Florida Water Resources Journal - January 2015 by Florida Water Resources Journal

Editor’s Office and Advertiser Information:

Florida Water Resources Journal 1402 Emerald Lakes Drive Clermont, FL 34711 Phone: 352-241-6006 • Fax: 352-241-6007 Email: Editorial, editor@fwrj.com Display and Classified Advertising, ads@fwrj.com

Business Office: P.O. Box 745, Windermere, FL 34786-0745 Web: http://www.fwrj.com General Manager: Editor: Graphic Design Manager: Mailing Coordinator:

Michael Delaney Rick Harmon Patrick Delaney Buena Vista Publishing

Published by BUENA VISTA PUBLISHING for Florida Water Resources Journal, Inc. President: Richard Anderson (FSAWWA) Peace River/Manasota Regional Water Supply Authority Vice President: Greg Chomic (FWEA) Heyward Incorporated Treasurer: Rim Bishop (FWPCOA) Seacoast Utility Authority Secretary: Holly Hanson (At Large) ILEX Services Inc., Orlando

Moving? The Post Office will not forward your magazine. Do not count on getting the Journal unless you notify us directly of address changes by the 15th of the month preceding the month of issue. Please do not telephone address changes. Email changes to changes@fwrj.com, fax to 352-241-6007, or mail to Florida Water Resources Journal, 1402 Emerald Lakes Drive, Clermont, FL 34711

News and Features 14

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Membership Questions

Training Questions FSAWWA: Donna Metherall – 407-957-8443 or fsawwa.donna@gmail.com FWPCOA: Shirley Reaves – 321-383-9690

For Other Information DEP Operator Certification: Ron McCulley – 850-245-7500 FSAWWA: Peggy Guingona – 407-957-8448 Florida Water Resources Conference: 888-328-8448 FWPCOA Operators Helping Operators: John Lang – 772-559-0722, e-mail – oho@fwpcoa.org FWEA: Karen Wallace, Executive Manager – 407-574-3318

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Got A Permit Renewal? Facing Shifting Regulations Using Collaborative Permitting—Katherine D. Ovalle La Torre, Terri S. Holcomb, Patricia DiPiero, Howard S. Wegis, and Darryl A. Parker Immokalee Water and Sewer District: Case Study of Effective Biosolids Management— Gary Ferrante, Kevin Higginson, Tom Welch, and Eva Deyo Don’t Pass on the Gas: More Bang for Your Biogas Buck—Matthew Munz and Bruce Petrik You Don’t Know What You’re Missing: Designing a Grit Removal System That Works—Marcia Sherony and Pat Herrick Continuous Rotating Belt Filtration for Primary Treatment and Combined Sewer Overflows—Miguel Gutierrez

Florida Water Resources Conference CEU Challenge TREEO Center Training FWPCOA Online Training Institute FSAWWA Training FWPCOA State Short School ISA Water/Wastewater and Automated Controls Symposium AWWA/AMTA Membrane Technology Conference FWPCOA Training Calendar

Columns 46 54 56 57

Certification Boulevard—Roy Pelletier FWEA Chapter Corner—Amy M. Baricevich and Samantha Nehme Legal Briefs—Gerald Buhr Process Page—Kristiana Dragash C Factor—Jeff Poteet FSAWWA Speaking Out—Mark Lehigh

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New Products Service Directories Classifieds Display Advertiser Index

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Technical Articles 4

FSAWWA: Casey Cumiskey – 407-957-8447 or fsawwa.casey@gmail.com FWEA: Karen Wallace, Executive Manager – 407-574-3318 FWPCOA: Darin Bishop – 561-840-0340

Education and Training

AWWA Exemplary Source Water Protection Award Recognizes Water Quality Protection Programs King Elected as FWPCOA President 2014-2015 FSAWWA Board of Governors FWRJ Looking for Articles and Column Information Florida Firm Receives Chamber of Commerce Recognition FWEA/FWRC Operations Challenge Meet and Greet Evaluation of a Composting System Using Sludge From Wastewater Treatment Plants—Hector G. Avilan News Beat FSAWWA Awards FSAWWA Legislative Day in Tallahassee FSAWWA Drop Savers Contests FWEA Wastewater Collection System of the Year Award

Departments

Websites Florida Water Resources Journal: www.fwrj.com FWPCOA: www.fwpcoa.org FSAWWA: www.fsawwa.org FWEA: www.fwea.org and www.fweauc.org Florida Water Resources Conference: www.fwrc.org Throughout this issue trademark names are used. Rather than place a trademark symbol in every occurrence of a trademarked name, we state we are using the names only in an editorial fashion, and to the benefit of the trademark owner, with no intention of infringement of the trademark. None of the material in this publication necessarily reflects the opinions of the sponsoring organizations. All correspondence received is the property of the Florida Water Resources Journal and is subject to editing. Names are withheld in published letters only for extraordinary reasons. Authors agree to indemnify, defend and hold harmless the Florida Water Resources Journal Inc. (FWRJ), its officers, affiliates, directors, advisors, members, representatives, and agents from any and all losses, expenses, third-party claims, liability, damages and costs (including, but not limited to, attorneys’ fees) arising from authors’ infringement of any intellectual property, copyright or trademark, or other right of any person, as applicable under the laws of the State of Florida.

ON THE COVER: The Virginia Key Wastewater Treatment Plant in Miami. The white building on the far left houses oxygen generation equipment, the two towers provide cryogenic cooling, and the odor control building is on the right. (photo: Michael Gardner)

Volume 67

January 2015

Number 1

Florida Water Resources Journal, USPS 069-770, ISSN 0896-1794, is published monthly by Florida Water Resources Journal, Inc., 1402 Emerald Lakes Drive, Clermont, FL 34711, on behalf of the Florida Water & Pollution Control Operator’s Association, Inc.; Florida Section, American Water Works Association; and the Florida Water Environment Association. Members of all three associations receive the publication as a service of their association; $6 of membership dues support the Journal. Subscriptions are otherwise available within the U.S. for $24 per year. Periodicals postage paid at Clermont, FL and additional offices.

POSTMASTER: send address changes to Florida Water Resources Journal, 1402 Emerald Lakes Drive, Clermont, FL 34711

Florida Water Resources Journal • January 2015

F W R J

Got A Permit Renewal? Facing Shifting Regulations Using Collaborative Permitting Katherine D. Ovalle La Torre, Terri S. Holcomb, Patricia DiPiero, Howard S. Wegis, and Darryl A. Parker 5-mil-gal-per-day (mgd) advanced wastewater treatment facility in Fort Myers has a discharge permit that required renewal in 2013. It was originally built in the 1980s to serve communities in south Fort Myers and some unincorporated areas of Lee County and has expanded to increase its capacity to serve the growing population in the service area. The facility utilizes an oxidation ditch aeration/activated sludge process with nutrient removal and chlorination/dechlorination to treat raw wastewater. The plant’s effluent is subsequently reused through reclaimed water irrigation of golf courses and public access residential reuse. When the effluent flow exceeds the demands of the reclaimed system, the facility directs the excess treated effluent to a surface water discharge into the Caloosahatchee River, which is a Class III marine water. Due to impeccable operations by the staff and proactive repair and rehabilitation investments made by the utility/owner, in the five years that the current permit has been valid, the facility was mostly free of permit violations and nuisance complaints despite high population density within its service area. The only significant violation involved an exceedance of dichlorobromomethane (DCBM) limits, which led to a consent order from the Florida Department of Environmental Protection (FDEP) in 2011. Outside of this obstacle, the potential challenges this renewal process would face were mostly related to evolving regulations, either relatively new, such as the Biosolids Rule, or imminent, such as the Numeric Nutrient Criteria (NNC). This article describes how the utility/owner worked with HDR to focus on three specific areas to meet permitting requirements. The initial discussion summarizes the impact of these regulations in the permit renewal process, as well as the resolution of the consent order through a mixing zone allowance, changes in groundwater monitoring, and reporting updates to make reuse flow data collection more efficient without losing significance in the results. Second, the article highlights the utility’s continuous efforts to streamline its record keeping procedures, making the required data compilation for future applications a more straightfor-

ward endeavor in comparison to previous permit renewals. And third, it provides practical recommendations that the utility/owner and similar utilities can consider and apply in the permit renewal processes to facilitate navigation through any related regulatory and operational challenges. Similar to many treatment facilities in large cities throughout Florida, the wastewater treatment plant (WWTP) is in close proximity to residences and schools that surround the facility on all sides. The sensitivity of these neighbors to odors and other nuisances, in combination with increased regulations, make it essential that the WWTP’s operations and reporting protocols be managed and documented effectively.

Treatment Process The WWTP has a permitted capacity of 5 mgd and can discharge its treated effluent to a public access reclaimed water system, or to the Caloosahatchee River. The treatment process follows this sequence: Preliminary Treatment: Raw wastewater is combined with return activated sludge (RAS) prior to screening and grit removal. Biological Treatment: Carbonaceous biochemical oxygen demand (CBOD) oxidation and some nitrification take place in oxidation ditches mixed by stationary brush aerators. Clarification and Phosphorus Removal: Alum is added for phosphorus removal downstream of the oxidation ditches. Settling of the active biomass takes place in the clarification basins and is pumped to sludge processing as waste activated sludge (WAS) or recycled to the oxidation ditches or the headworks as RAS. Denitrification: The clarified effluent goes through gravel and sand filters that provide further solids removal and denitrification aided by the addition of methanol. Filtration is followed by reaeration in the filter backwash basin. Disinfection and Dechlorination: Sodium hypochlorite is added to the reaerated effluent and sent to the chlorine contact chambers, which provides contact time for

January 2015 • Florida Water Resources Journal

Katherine D. Ovalle La Torre, P.E., is project engineer and Terri S. Holcomb, P.E., is project manager with HDR Inc. in Tampa. Patricia DiPiero is legislative and compliance programs manager, Howard S. Wegis is staff engineer, and Darryl A. Parker is lead operator with Lee County Utilities in Fort Myers.

disinfection. The chlorinated effluent overflows into the dechlorination basin after addition of sodium bisulfite to remove the remaining chlorine from the water. Effluent Pumping and Storage: The final dechlorinated effluent is conveyed to the ground storage tank by the transfer pumps. Reclaim high-service pumps distribute this effluent to the reclaimed water system, an interconnection to another treatment facility, and/or the river outfall. Solids Handling and Processing: The WAS is pumped from the clarifiers to sludge holding tanks, where it is accumulated until it is dewatered on site by a mobile centrifuge or at another treatment facility for processing. The dewatered biosolids are taken to the Lee/Hendry County Class I landfill for further treatment and/or disposal.

Permit History The last permit cycle for the WWTP started in 2008. In the five years of its validity, the WWTP had been exempt from several new regulations that would normally apply to the facility and could potentially impact its operation. These new regulations included the NNC and the Biosolids Rule. In terms of violations, proactive operation and maintenance (O&M) policies of the utility/owner kept such instances to a minimum. An indication of this trend can be found in the small amount of exceedances observed between December 2012 and March 2013. Only five instances were observed during this time period, mostly related to minor operational issues that Continued on page 6

Continued from page 4 were quickly corrected and upgrades to the WWTP’s dechlorination system. The only exceedance of significance between 2008 and 2013 was an annual average exceedance of the discharge permit’s DCBM limits reported in 2010. This chemical is a disinfection byproduct (DBP), which is generated as a result of the WWTP’s disinfection process. This violation resulted in the issuance of a consent order in May 2011, which is described later. Additionally, there has only been a single nuisance complaint between 2008 and 2013 from the surrounding neighbors to the WWTP regarding fleeting odors originating from headworks improvements. This is yet another indication of the impeccable operation of the WWTP over the years. In 2013, the utility/owner retained the services of HDR to prepare documentation for the discharge permit renewal application and provide support for additional permit requirements

and preapplication meetings with FDEP. The prepared documents included a Capacity Analysis Report (CAR) that evaluated the WWTP’s present and future flows and water quality demands, as well as a comprehensive O&M performance review that extensively assessed various aspects of the WWTP’s operations and equipment.

Permit Renewal Development Data Management Up until April of 2011, the WWTP’s operators would populate spreadsheets to track the treatment performance of the plant based on routine monitoring and laboratory testing. These spreadsheets would populate discharge monitoring reports (DMRs) that would be submitted monthly to FDEP. Several recognized drawbacks to this method of data entry include: High investment of time that could be used in other, more critical tasks.

Unreliability of monthly output due to high potential of data entry errors. Inaccuracies in monthly data would cascade into quarterly, semiannual, and annual averages and/or reports. In April 2011, the utility/owner implemented a program that provided a centralized data management system, dramatically cutting the time investment required to keep track of the WWTP’s water quality parameters. This software also generated on-demand reports of relevant averages and trends of the collected data. The combination of data sources proved to be a time-consuming endeavor for the compilation of the required data to be included in the permit renewal application documents. Dichlorobromomethane Exceedance, Consent Order, and Mixing Zone Report Due to the 2010 DBP violation, the utilContinued on page 8

Figure 1. Wastewater Treatment Plant Process Flow Diagram (1 of 2)

Figure 2. Wastewater Treatment Plant Process Flow Diagram (2 of 2)

January 2015 • Florida Water Resources Journal

Continued from page 6 ity/owner was faced with the possibility of expensive changes to the WWTP’s disinfection system, along with the difficulty of completing the design, construction, and implementation of such changes in a timely manner. After some negotiation with FDEP, the May 2011 consent order issued for this occurrence required the facility to apply for a DCBM mixing zone by June 2013 and to submit quarterly reports of the status and progress of these efforts. The utility/owner procured the services of a consultant to evaluate the behavior of the treated effluent discharged by the WWTP into the Caloosahatchee River and the consequent receiving water quality variations. The results of this study were summarized in a mixing zone report

issued in November 2012, which became the basis for the application required by the consent order. Instead of pursuing a stand-alone application process for the mixing zone, the utility/owner decided to integrate the proposed mixing zone report and application into the permit renewal process. This approach, welcomed by the FDEP, consolidated the two permits and streamlined the regulatory process. Numeric Nutrient Criteria and Total Maximum Daily Load Report After many years of using narrative criterion to regulate nutrients in Florida’s waters, the FDEP moved in conjunction with the U.S. Environmental Protection Agency (EPA) to enact rules based on the NNC. At the time of the per-

Figure 3. Groundwater Wells: Total Dissolved Solids, mg/L

Figure 4. Groundwater Wells: Chloride, mg/L as Cl

January 2015 • Florida Water Resources Journal

mit’s renewal, an implementation plan1 illustrating plans for statewide application of the proposed regulation was published. In order to interpret the potential impact of the NNC regulations on the WWTP, the hierarchical approach described in the document was reviewed. Given that a total maximum daily load (TMDL) report for nutrients2 was issued for the Caloosahatchee River Basin, the hierarchy presented in the implementation plan dictates that the limits would be based on the existing TMDL. The TMDL concluded that none of the facilities permitted to discharge at the time of its issue (including the WWTP) were “expected to cause or contribute substantially to the nutrient load,” and were assigned their permitted loads at the time. The final form of the implementation plan was released in April 2013 with no changes to the approach described. Consequently, no changes to the permitted limits were expected stemming from enactment of the NNC or the 2009 TMDL on the 2013 renewal cycle. Any updates or changes to the Caloosahatchee’s TMDLs for total nitrogen or other constituents (if any) may be relevant to future permit renewals. Biosolids Rule In 2010, sweeping changes in the guidelines for the management of biosolids generated at WWTPs were enacted. In the case of this particular facility, the impact of this update would be largely in the reporting associated with the disposal of its biosolids. For the permit application, FDEP agreed in a preapplication meeting that additional language in the O&M performance report could satisfy the requirements of this rule. The section provided details regarding a biosolids storage and disposal plan reflecting the current procedures used to manage biosolids in the WWTP and future efforts to improve their solids handling facilities that are expected to include onsite dewatering. Groundwater Monitoring Wells Relocation The 2008 permit required groundwater monitoring of a network of seven 15-ft-deep wells that help assess the surficial aquifer in the proximity of reclaimed water users. A July 2011 inspection from FDEP found several deficiencies in these wells, noting in particular, multiple exceedances of groundwater quality standards in background monitoring wells. This could indicate that the location of the monitoring wells may not be suited to accurately represent the effects of reclaimed water application on groundwater quality. This phenomenon was verified in the review of groundwater monitoring reports for the permit renewal application, particularly

in total dissolved solids, chloride, total sulfate, and dissolved sodium measurements, as shown in Figures 3 through 6, respectively. As a result of this inspection, the utility/owner requested a revision of the groundwater monitoring plan based on an evaluation completed by a consultant. This update would eliminate the existing wells and replace them with four new ones at a new location in order to get a more representative assessment of the impact of reclaimed water application in groundwater quality. The FDEP issued a minor permit modification in February 2011, updating the groundwater monitoring plans as requested. Inclusion of the updated groundwater monitoring plan in the permit renewal, along with discussions with FDEP staff at the preapplication meeting, allowed the utility/owner to incorporate additional information into the permit renewal, consolidating and formalizing the regulatory process.

on background well readings. Elevated concentrations and exceedances could be a sign that an accurate representation of the groundwater conditions is not being provided. Ensure that at least three thorough laboratory tests are performed throughout the permit cycle. Review Section 3A (parts 12 through 14) of FDEP’s Form 2A3 for the applicable schedules, methodologies, and constituents, depending on permitted flow capacity and pretreatment program requirements.

References 1

Florida Department of Environmental Protection (March 2013). Implementation of

Florida’s Numeric Nutrient Standards. Retrieved from http://www.dep.state.fl.us/secretary/news/2013/03/NNC_Implementation_311-13.pdf Florida Department of Environmental Protection (September 2009). Final TMDL Report – Nutrient TMDL for the Caloosahatchee Estuary. Retrieved from http://www.dep.state.fl.us/ water/tmdl/docs/tmdls/final/gp3/tidalcaloosa-nutr-tmdl.pdf Florida Department of Environmental Protection (June 2001). Wastewater Permit Application Form 2A for Domestic Wastewater Facilities. Retrieved from http://www.dep.state.fl.us/ water/wastewater/forms/pdf/620_2_.pdf

Lessons Learned for Future Permit Applications In a normal situation, some of the items described may have warranted stand-alone permitting processes. In this case, close collaboration among the utility/owner, HDR, and FDEP allowed this permit renewal to be streamlined through open dialogue and preapplication meetings. This team endeavor saved time, cost, and effort for all the parties involved by addressing all regulatory drivers impacting the WWTP into a single permitting process. Additional lessons that can be applied in permit renewal applications include: Efficient water quality data management is crucial for ongoing compliance, as well as the preparation of reports required for the renewal application. This may require an upfront investment from utilities/owners, but the return on the investment for day-to-day operations in treatment plants would be recognized immediately. Utilities/owners should continuously monitor the status of regulations as they apply to their facilities. Some of the regulations may not apply until such facilities are up for permit renewal, but it gives utilities/owners a good idea of impending changes to expect in the new permit. Ultimately, this would help utilities/owners prepare for significant regulatory requirements in the future. Mixing zones are a viable avenue to mitigate the expense of costly treatment changes that may be required due to ongoing violations, as long as they fulfill the criteria outlined by FDEP. If a groundwater monitoring plan is part of the permit, utility/owners should keep an eye

Figure 5. Groundwater Wells: Total Sulfate, mg/L

Figure 6. Groundwater Wells: Dissolved Sodium, mg/L Florida Water Resources Journal • January 2015

AWWA Exemplary Source Water Protection Award Recognizes Water Quality Protection Programs The American Water Works Association (AWWA), an international nonprofit and educational society, is the largest and oldest organization of water professionals in the world, with a membership of approximately 50,000 people and 4,600 utilities that supply water to 180 million people in North America. Members represent treatment plant operators and managers, scientists, environmentalists, manufacturers, academicians, regulators, and others who hold genuine interest in water supply and public health. The organization is considered an authoritative resource on safe water. Each year, AWWA recognizes the efforts of source water protection programs. Through its Exemplary Source Water Protection Award program, three awards are issued to organizations representing different water-system-size classifications based on the population served. Organizations may self-nominate or be nominated by an AWWA member, regulatory agency responsible for source water protection, a local chapter of the National Rural Water Association, or regional authorities. The Exemplary Source Water Protection Award recipients have included:

(SIZE CLASS, Recipient, AWWA Section) LARGE GROUNDWATER SYSTEM City of Kalamazoo, Mich. Michigan VERY LARGE/MIXED SYSTEM Spokane Aquifer Joint Board, Wash. Pacific Northwest Nominations are judged on how well a water system meets six components of AWWAâ&#x20AC;&#x2122;s source water protection standard: Program vision Source water characterization Source water protection goals Development of an action plan Implementation of the action plan Periodic evaluation and revision of the entire program In addition to how well a source water protection program satisfies each of the six program components outlined for the AWWA standard, the award is also based on the following three criteria: Effectiveness of the program Innovativeness of the program approach Difficulties overcome by the organization in

satisfying the eligibility criteria The first six items directly relate to the program component criteria set forth in the AWWA Standard for Source Water Protection (ANSI/AWWA G300-07). Applicants are strongly encouraged to review the specific criteria for each of the six program components provided in the AWWA standard, which is available from the AWWA Bookstore (http://www.awwa.org/publications.aspx). Nomination packages for the upcoming award are due to the staff secretary, AWWA Water Resource Sustainability Division, by Thursday, Jan. 15, 2015. Typically, sections may choose to work with water utilities and suppliers in their region to submit nominations; however, a water utility/supplier may self-nominate. Please feel free to provide this information to others who might be interested in nomination for the award. For more information about the award, including nomination forms, visit: http://www.awwa.org/membership/get-involved/awards/award-details/articleid/90/exemplary-source-water-protection-award.aspx.

Lake Maumelle in Pinnacle Mountain State Park near Little Rock, Ark., is one of the source waters for Central Arkansas Water that serves approximately 400,000 customers.

January 2015 â&#x20AC;˘ Florida Water Resources Journal

King Elected as FWPCOA President

Thomas King was elected as president of the Florida Water and Pollution Control Operators Association (FWPCOA) for 2015 by the organizationâ&#x20AC;&#x2122;s board of directors at their October 2014 meeting. King is utility manager for Kennedy Space Center Utilities in Orlando. He has been at the Space Center for over 25 years, in charge of plumbing, water

treatment, and fire systems. He is the current instructor for courses covering maintenance and operation of fire sprinkler systems, which are taught in preparation for National Institute for Certification in Engineering Technologies (NICET) certifications. He is a current member of the Florida Fire Sprinkler Association. King served in the U.S. Army and was honorably discharged in 1972; he received his first wastewater/water operator license that same year. In addition to this license, he has a water operator license, a backflow tester certification, a water distribution license, an effluent disposal certification,

January 2015 â&#x20AC;˘ Florida Water Resources Journal

and a wastewater collection system license. He was president of FWPCOA in 2008 and has been a member of the state board of directors since 2006. He is the current director of Region 3 of FWPCOA. An instructor for the association since 1980, King has taught utility management, trenching and shoring, and an array of other utility courses. He is the state chair of the Stormwater Committee and received the Pat Flanagan Award, which is given to instructors for outstanding achievement. He was also voted into the Florida Select Society of Sanitary Sludge Shovelers; when you see him,

ask him about the small silver shovel he wears. Prior to his job at the Space Center, King was the superintendent of utilities for Brevard County for five years and held the position of utility director for Seacoast Utilities in Palm Beach Gardens. He is has six children and is engaged to be married soon.

Operators: Take the CEU Challenge! Members of the Florida Water & Pollution Control Association (FWPCOA) may earn continuing education units through the CEU Challenge! Answer the questions published on this page, based on the technical articles in this month’s issue. Circle the letter of each correct answer. There is only one correct answer to each question! Answer 80 percent of the questions on any article correctly to earn 0.1 CEU for your license. Retests are available. This month’s editorial theme is Wastewater Treatment . Look above each set of questions to see if it is for water operators (DW), distribution system operators (DS), or wastewater operators (WW). Mail the completed page (or a photocopy) to: Florida Environmental Professionals Training, P.O. Box 33119, Palm Beach Gardens, FL 334203119. Enclose $15 for each set of questions you choose to answer (make checks payable to FWPCOA). You MUST be an FWPCOA member before you can submit your answers!

___________________________________________ SUBSCRIBER NAME (please print)

Article 1 ________________________________________ LICENSE NUMBER for Which CEUs Should Be Awarded

Article 2 ________________________________________ LICENSE NUMBER for Which CEUs Should Be Awarded

If paying by credit card, fax to (561) 625-4858 providing the following information:

Earn CEUs by answering questions from previous Journal issues!

___________________________________________

Contact FWPCOA at membership@fwpcoa.org or at 561-840-0340. Articles from past issues can be viewed on the Journal website, www.fwrj.com.

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You Don’t Know What You’re Missing: Designing a Grit Removal System That Works

Immokalee Water and Sewer District: Case Study of Effective Biosolids Management

Marcia Sheroney and Pat Herrick

Gary Ferrante, Kevin Higginson, Tom Welch, and Eva Deyo

(Article 1: CEU = 0.1 WW)

(Article 2: CEU = 0.1 WW)

1. According to the Water Environment Federation (WEF) Manual of Practice No. 8, design intent for grit removal systems targets grit of ____ microns and larger. a. 265 b. 2.65 c. 210 d. 2.10

1. The request for proposals indicated that waste activated sludge would be provided to the contractor at ___ percent solids. a. 1.8 b. 3.0 c. 5.0 d. 18

2. When a screw classifier is fed at a high surface loading rate, most of the organics a. overflow along with the lighter grit. b. are left behind. c. squeezed from the grit stream. d. are unaffected. 3. Which of the following materials has a specific gravity greater than silica sand? a. Quartz sand b. Clay c. Asphalt d. None of the above.

2. Which of the following Florida rules governs the land application of biosolids? a. 62-602 b. 6-610 c. 62-640 d. 40 CFR 504 3. The process selected by the Immokalee Water and Sewer District uses quicklime to adjust biosolids pH to a. a maximum of 8.5. b. exactly 10. c. above 12. d. none of the above.

4. Grit removal basins designed to take advantage of centrifugal force to aid settling are known as _______________ basins. a. gravity sedimentation b. aerated grit c. vortex d. vacuum

4. Fugitive lime dust is controlled by a. a pinch valve at the reactor discharge. b. hard piping or sealing connections to the mixing hopper. c. placing the entire process within a sealed building. d. a vacuum-regulated air odor control system.

5. A 100-micron particle having a specific gravity of 1.35 will settle _________ as the same size particle having a specific gravity of 2.65. a. half as fast b. one quarter as fast c. at the same rate d. twice as fast

5. Landfill disposal of biosolids is considered environmentally beneficial only when a. the landfill is located very near the wastewater treatment plant. b. grass or other crops are grown at the landfill. c. the landfill is equipped to convert methane to electricity. d. the correct ratio of biosolids to refuse can be maintained.

Florida Water Resources Journal • January 2015

2014-2015 FSAWWA BOARD OF GOVERNORS Executive Committee Mark D. Lehigh Chair Hillsborough County Water Resource Services 332 N. Falkenburg Road Tampa, Florida 33619 P: (813) 272-5977, ext. 43270 F: (813) 635-8152 E: lehighm@hillsboroughcounty.org Kimberly A. Kunihiro Chair-Elect Orange County Utilities 9124 Curry Ford Road Orlando, Florida 32825 P: (407) 254-9555 F: (407) 254-9558 E: kim.kunihiro@ocfl.net Grace M. Johns, Ph.D. Vice Chair Hazen and Sawyer P.C. 4000 Hollywood Blvd., Suite 750N Hollywood, Florida 33021 P: (954) 987-0066 F: (954) 987-2949 E: gjohns@hazenandsawyer.com

Robert J. Dudas Trustee Orange County Utilities 8100 Presidents Drive, Suite C Orlando, Florida 32809 P: (407) 836-6835 F: (407) 836-6862 E: bob.dudas@ocfl.net

Florida Section AWWA By Region

Ana Maria Gonzalez, P.E. General Policy Director Hazen and Sawyer P.C. 999 Ponce de Leon Blvd., Suite 1150 Coral Gables, Florida 33134 P: (954) 967-7040 E: agonzalez@hazenandsawyer.com

Carl R. Larrabee Jr., P.E. Past Chair St. Johns River Water Management District 525 Community College Parkway, S.E. Palm Bay, Florida 32909 P: (386) 329-4222 E: clarrabee@sjrwmd.com

Jacqueline W. Torbert Association Director Orange County Utilities Water Division 9150 Curry Ford Road, 3rd Floor Orlando, Florida 32825 P: (407) 254-9850 F: (407) 254-9848 E: jacqueline.torbert@ocfl.net

William G. Young Secretary St. Johns County Utilities 1205 State Road 16 St. Augustine, Florida 32084 P: (904) 209-2703 F: (904) 209-2702 E: byoung@sjcfl.us

Matt Alvarez, P.E. Alternate Association Director CH2M HILL Inc. 201 Alhambra Circle, Suite 600 Coral Gables, Florida 33134 P: (305) 443-6401 F: (305) 443-8856 E: matt.alvarez@ch2m.com

Kim Kowalski Treasurer Wager Company of Florida Inc. 720-B Industry Road Longwood, Florida 32750 P: (407) 834-4667 F: (407) 831-0091 E: kkowalski@wagerco.com

Trustees

Fred Bloetscher, Ph.D., P.E. Trustee Florida Atlantic University P.O. Box 221890 Hollywood, Florida 33022 P: (239) 250-2423 F: (954) 581-5076 E: h2o_man@bellsouth.net

January 2015 â&#x20AC;˘ Florida Water Resources Journal

Christine S. Ellenberger Trustee Jacobs Engineering 245 Riverside Avenue, Suite 300 Jacksonville, Florida 32202 P: (904) 636-5432 ext. 127 F: (904) 636-5433 E: christine.ellenberger@jacobs.com Mark Kelly Trustee Garney Construction 370 E. Crown Point Road Winter Garden, Florida 34787 P: (321) 221-2833 F: (407) 287-8777 E: mkelly@garney.com Dave Slonena Trustee Pinellas County Utilities 14 S Ft. Harrison Avenue Clearwater, Florida 33756 P: (727) 464-4441 F: (727) 464-3595 E: dslonena@pinellascounty.org

Council Chairs Tyler Tedcastle, P.E. Administrative Council Chair Carter & VerPlanck Inc. 4910 W. Cypress Street Tampa, Florida 33607 P: (850) 264-9391 F: (813) 282-8216 E: tylertedcastle@carterverplanck.com Donnie Belloit Contractors Council Chair WPC Industrial Contractors Ltd. 11651 Philips Highway Jacksonville, Florida 32256 P: (904) 268-0099 F: (904) 268-2922 E: dbelloit@wpcind.com

Todd Lewis Manufacturers/Associates Council Chair U.S. Pipe and Foundry LLC 14580 St. Georges Hill Drive Orlando, Florida 32828 P: (407) 592-1175 F: (877) 505-1570 E: tlewis@uspipe.com

Christopher Jarrett Region III Chair (Central Florida) American Cast Iron Pipe Company 2200 Winter Springs Blvd., Suite 106-294 Oviedo, Florida 32765 P: (412) 721-6338 F: (205) 307.3824 E: cjarrett@american-usa.com

Steve Soltau Operators Council Chair Pinellas County Utilities 3655 Keller Circle Tarpon Springs, Florida 34688 P: (727) 453-6990 F: (727) 453-6962 E: ssoltau@pinellascounty.org

Emilie Moore, P.E. Region IV Chair (West Central Florida) Tetra Tech 400 N. Ashley Drive, Suite 2600 Tampa, Florida 33602 P: (727) 709-1705 F: (813) 282-7893 E: emilie.moore@tetratech.com

Scott Richards, P.E. Public Affairs Council Chair Atkins 482 S. Keller Road Orlando, Florida 32810 P: (407) 806-4326 E: scott.richards@atkinsglobal.com

Ronald Cavalieri, P.E. Region V Chair (Southwest Florida) AECOM 4415 Metro Parkway, Suite 404 Fort Myers, Florida 33916 P: (239) 278-7996 F: (239) 278-0913 E: ronald.cavalieri@aecom.com

Roberto Denis, P.E. Technical and Education Council Chair Liquid Solutions Group LLC 680 Valley Stream Drive Geneva, Florida 32732 P: (407) 349-3900 F: (407) 349-3935 E: rdenis@liquidsolutionsgroup.com Rob Teegarden, P.E. Utility Council Chair Orlando Utilities Commission 3800 Gardenia Avenue P.O. Box 3193 Orlando, Florida 32802 P: (407) 434-2570 F: (407) 434-2671 E: rteegarden@ouc.com

Region Chairs Edward A. Bettinger, RS, MS Region I Chair (North Central Florida) DOH â&#x20AC;&#x201C; Bureau of Water Programs 4052 Bald Cypress Way, Bin #A-08 Tallahassee, Florida 32399 P: (850) 245-4444 ext. 2696 F: (850) 487-0864 E: ed.bettinger@flhealth.gov Andrew May, P.E. Region II Chair (Northeast Florida) JEA 21 W. Church Street Jacksonville, Florida 32202 P: (904) 665-4510 F: (904) 665-8099 E: mayar@jea.com

Kyle A. Kellogg Interim Region X Chair (West Central Florida) Atkins 100 Paramount Drive, Suite 207 Sarasota, Florida 34232 P: (941) 225-4823 E: kyle.kellogg@atkinsglobal.com Kristen Sealey Region XI Chair (North Florida) Gainesville Regional Utilities P.O. Box 147051 Gainesville, Florida 32614 P: (352) 393-1621 F: (352) 334-3151 E: sealeykm@gru.com Donald E. Hamm Region XII Chair (Central Florida Panhandle) Bay County Utility Services 3410 Transmitter Road Panama City, Florida 32404 P: (850) 248-5010 F: (850) 248-5006 E: dhamm@baycountyfl.gov

Section Staff

Mike Bailey, P.E. Region VI Chair (Southeast Florida) Cooper City Utilities 11791 S.W. 49th Street Cooper City, Florida 33330 P: (954) 434-5519 F: (954) 680-3159 E: mbailey@coopercityfl.org

Peggy Guingona Executive Director Florida Section AWWA 1300 9th Street, Building B-124 St. Cloud, Florida 34769 P: (407) 957-8449 F: (407) 957-8415 E: fsawwa@gmail.com

Juan Aceituno, P.E. Region VII Chair (South Florida) CH2M HILL Inc. 3150 S.W. 38 Avenue, Suite 700 Miami, Florida 33146 P: (305) 443-6401 ext. 59120 F: (305) 443-8856 E: juan.aceituno@ch2m.com Brad Macek Region VIII Chair (East Central Florida) City of Port St. Lucie Utility Systems Department 900 S.E. Ogden Lane Port St. Lucie, Florida 34983 P: (772) 873-6400 F: (772) 873-6405 E: bmacek@cityofpsl.com Monica Autrey Region IX Chair (West Florida Panhandle) Destin Water Users Inc. P.O. Box 308 Destin, Florida 32540 P: (850) 837-6146 F: (850) 837-0465 E: mautrey@dwuinc.com

Casey Cumiskey Membership Specialist/Training Coordinator Florida Section AWWA 1300 9th Street, Building B-124 St. Cloud, Florida 34769 P: (407) 957-8447 F: (407) 957-8415 E: fsawwa.casey@gmail.com Donna Metherall Training Coordinator Florida Section AWWA 1300 9th Street, Building B-124 St. Cloud, Florida 34769 P: (407) 957-8443 F: (407) 957-8415 E: fsawwa.donna@gmail.com Jenny Arguello Staff Assistant Florida Section AWWA 1300 9th Street, Building B-124 St. Cloud, Florida 34769 P: (407) 957-8448 F: (407) 957-8415 E: fsawwa.jenny@gmail.com

Florida Water Resources Journal â&#x20AC;˘ January 2015

F W R J

Immokalee Water and Sewer District: Case Study of Effective Biosolids Management Gary Ferrante, Kevin Higginson, Tom Welch, and Eva Deyo he Immokalee Water and Sewer District (IWSD) is currently paying a premium to have the biosolids from its wastewater treatment plant (WWTP) dewatered and hauled to a landfill. The annual cost to IWSD for contract dewatering, hauling, and landfill disposal has historically been upwards of $500,000. Although landfill disposal of biosolids is still common in Florida, it should not be viewed as a long-term solution. Landfill disposal is considered to be environmentally beneficial only when the landfill is equipped to recover and convert methane gas into electricity. Landfills are carefully engineered and monitored to ensure protection of groundwater and surface water and stability of the landfill mass. As such, landfills have a limited capacity to accept biosolids in proportion to the total tons of refuse received. Most importantly, landfill disposal does not take advantage of the nutrient value and soil-building properties of biosolids and takes up landfill space that can be better used for other materials. The updated Florida Biosolids Regulation, Chapter 62-640, F.A.C., became effective on Aug. 29, 2010. After four years, the full impact of this regulation is now being felt, particularly where Class B biosolids are produced and disposal is required. These regulations limit the number of available disposal sites as each site is required to complete and submit a nutrient analysis plan to the state for approval. Typically, this nutrient management plan is completed at significant expense. In addition, the available sites for Class B biosolids land application may now be much farther from the WWTP, thereby increasing transportation costs. Many WWTP operators are starting to incur increased costs to haul and dispose of biosolids, which is directly attributed to the new state regulations. In some cases, the costs of properly managing and utilizing these solids have nearly doubled. To address this concern, Class AA biosolids, in conjunction with designated fertilizer licenses from the Florida Department of Agriculture and Consumer Services (FDACS), are becoming the new Florida industry standard. A number of different factors should be considered when evaluating technologies that produce Class AA biosolids, including capital

cost, operating cost, reliability, ease of operation, complexity and safety of operation, odors and side streams of the processes, required space, and the ease of disposal. As part of a strategy to reduce operational costs and improve biosolids management, IWSD directed its engineering consultant, Greeley and Hansen, to prepare and issue two requests for proposals (RFPs) in the summer of 2012. The RFP-1 requested design-buildfinance (DBF) teams to provide a detailed lease to plan, design, and finance the entire cost of a Class AA biosolids production facility. The RFP-2 incorporated a land-lease option to allow an outside vendor to design, build, finance, and operate the facility. Under each RFP, the total annual payment, plus the annual operation and maintenance (O&M) cost, could not exceed $470,000, which is the existing operating cost for Class B biosolids dewatering and disposal. The facility would include permanent dewatering equipment and Class AA biosolids processing equipment, and it also needed to fit in a small footprint to be centrally located on the WWTP site where existing dewatering beds were located. After consideration of the various proposals, IWSD selected Schwing Bioset’s DBF proposal under RFP-1. The lease-to-own agreement allows IWSD to purchase the facility at any time during the 10-year, lease-to-own agreement. Initially, the annual cost savings would be over $70,000 compared to the existing operations. At the end of the 10-year lease, the annual cost savings is expected to be almost $400,000 and the equipment will be owned by IWSD. After giving consideration to the amount of interest that would be charged, the board of directors of IWSD opted to pay for the system entirely from its own funds. The IWSD took the opportunity to achieve a cost savings versus maintaining the current Class B operations. The result is a long-term Class AA biosolids production facility owned by IWSD that will meet the needs for many years into the future. The permanent dewatering facility will be directly connected to the Class AA process and will be housed under the same roof in a compact operation, which optimizes materials handling. The agreement allows

January 2015 • Florida Water Resources Journal

Gary Ferrante, P.E., and Kevin Higginson, P.E., are civil sanitary engineers with Greeley and Hansen in Fort Myers; Tom Welch is the southeast regional sales manager with Schwing Bioset in Fort Myers; and Eva Deyo is executive director of the Immokalee Water and Sewer District in Immokalee.

IWSD to maintain ownership of the Class AA biosolids and utilize them on its sprayfield as is currently permitted through the Florida Department of Environmental Protection (FDEP). The IWSD currently leases the 300-acre sprayfield land to a cattle farmer and is required to fertilize the property annually. The use of the Class AA fertilizer produced at the new biosolids facility will eliminate the need and cost for commercial fertilizer, and at the same time, eliminate the hauling and disposal costs of material taken to the landfill. The new facility was put into operation in April 2014. This article focuses on the IWSD case study to provide a cost-effective solution for biosolids handling, which is a challenge that other smaller utilities are now struggling with due to the increase in hauling and disposal costs resulting from the new disposal regulations.

Immokalee Water and Sewer District Experience The IWSD’s WWTP currently produces Class B biosolids. The WWTP was originally designed with six sludge drying beds and had space for three more to be constructed at a later date. At the time the WWTP was designed, the common practice was land application of Class B biosolids on agricultural land. The IWSD had six permitted land application sites. In 2007, the United States Department of Agriculture (USDA) and FDEP were contemplating changes to the biosolids land application regulations, which would add phosphorus limits and thus restrict land application of Class B municipal biosolids on agricultural lands. The IWSD’s consultant at that time wrote a report titled, “Biosolids Disposal Alternatives Evaluation for the Immokalee Water and Sewer Dis-

trict Wastewater Treatment Plant.” This report compared several alternatives, but ultimately recommended the short-term solution of contract dewatering and hauling until the pending regulations came into effect to be sure that whatever was designed for the long-term solution would be in conformance with the regulations. Therefore, in 2007, the IWSD entered into a contract with Synagro for dewatering the Class B biosolids and hauling the dewatered solids to a landfill for disposal. The IWSD “piggybacked” on a bid and contract from Martin County with Synagro. Originally, the contract price was $46 per 1,000 gal, resulting in an annual cost of $309,000; however, the contract allowed Synagro to use the cost-of-living adjustment (COLA) to adjust disposal charges each year during the term of the contract. For the contract, the biosolids have been disposed of at the Okeechobee Landfill, which is located 102 mi from the WWTP. The total annual cost for biosolids disposal has reached $470,000 due to increased sludge quantities and unit disposal cost. The IWSD realized that it needed to explore options to reduce this cost. Also, the current contract with Synagro expired on May 31, 2013, and the IWSD board voted to renew the contract for one year. The current price is $50.73 per 1,000 gal. The IWSD board was split on whether to purchase the biosolids processing equipment or to simply act as the landlord and let another entity handle the operations. The board decided to issue two RFPs in July 2012. The RFP1 was for design-build-finance of the biosolids facility at the existing WWTP site. Under this

option, IWSD would own and operate the equipment. The RFP-1 Part 1 was for handling the sludge from the Immokalee WWTP only, and RFP-1 Part 2 was for converting the facility into a regional facility. The RFP-2 also had two parts: RFP-2 Part 1 was for a land lease for an entity to rent land from the IWSD for the sole purpose of constructing a regional Class A biosolids handling facility, and RFP-2 Part 2 was for contract dewatering and hauling, similar to the current arrangement with Synagro, while the regional facility was being designed, permitted, and constructed. Greeley and Hansen assisted the IWSD in developing the following criteria for RFP-1: 1. 188,000 gal per week of 1.5 percent solids waste activated sludge (WAS) at Immokalee only. 2. Provide dewatering equipment to process 1.5 percent solids sludge to 18 percent solids. 3. Expandable to regional facility to handle an additional 27,000 tons of 18 percent solids sludge (from Collier County facilities). 4. Convert dewatered solids into a beneficial fertilizer/soil amendment product. 5. Utilize existing 200 amp, 460 volt, threephase electric service. 6. Provide metal roof structure to house the equipment. 7. Equipment footprint to fit in one of the three cross-hatched areas available, shown in Figure 1. 8. Dried solids must meet Class A requirements (minimum). 9. Structural designs based on:

10. 11. 12. 13.

14.

15.

16. 17.

18.

a. 100 mi per hour (mph) sustained winds, 120 mph gusts, b. Exposure Class B, c. Occupancy Category II, and d. 20 pounds per sq ft (psf) roof live load. Signed and sealed structural drawings. Maximum of 16 hours/day operation. Provide list of references and FDEP-permitted installations in Florida. Provide list of personnel from the technology supplier, engineer, general contractor, and subcontractors working on this project, including documented similar experience and resumes. Provide documentation of financial strength of the entity or entities providing project financing. Provide general layout and general equipment arrangements for both Phase 1 and Phase 2. Provide process flow diagram for Phase 1 and Phase 2. Provide a narrative detailing the process for sludge treatment that specifically states the method of compliance with the FDEP 62-640.600 and 40 CFR 503 regulations. Include details for transporting sludge from the dewatering equipment to the sludge process equipment, plus details for accepting sludge from other facilities for Phase 2, as well as a narrative detailing the transition from Phase 1 to Phase 2. Also include the expected nitrogen/phosphorus/potassium (NPK) values of the final fertilizer/soil amendment product. Provide detailed list of equipment being Continued on page 22

Figure 1. Available Cross-Hatched Areas Florida Water Resources Journal • January 2015

Continued from page 21 provided for Phase 1 and Phase 2, including electrical phase, voltage, full load amps, and horsepower requirements (460V, threephase is available). 19. Provide detailed capital cost breakdown, including engineering, installation, and equipment for Phase 1 and Phase 2. 20. Provide minimum of three current quotes for each chemical required from different sources. 21. Provide detailed annual O&M cost breakdown for Phase 1 and Phase 2 with calculations including chemical dosing ratios based on the average chemical cost from the sources obtained above, electrical cost of $0.08 per kilowatt-hour, diesel fuel cost of $4.25 per gallon, plus all assumptions made. 22. Provide statement regarding the treatment plant operator class required to operate the system. 23. Provide a detailed lease-to-own plan to finance the entire cost, specifically stating the monthly payments, fixed interest rate, and length of term. For Phase 1, the total annual payment plus the annual O&M costs shall not exceed $470,000. 24. Provide tentative project schedule indicating the number of days from Notice to Proceed until completion of construction for Phase 1 and Phase 2. 25. Provide information regarding training technical support and maintenance responsibilities during lease period. 26. Provide detailed information regarding the lengths and types of warranties being provided after the ownership transfer occurs when the equipment has been paid off. Greeley and Hansen also assisted IWSD in developing the following criteria for RFP-2:

1. 188,000 gal per week of 1.5 percent solids WAS, Immokalee only. 2. Provide list of references and FDEP-permitted installations in Florida. 3. Provide list of all personnel from the technology supplier, engineer, general contractor, and subcontractor who will be working on the project, including documented similar experience and resumes. 4. Provide documentation of the financial strength of the entity or entities providing project financing. 5. Provide a general layout and general equipment arrangement. 6. Provide a process flow diagram. 7. Provide a narrative detailing the process for sludge treatment that specifically states the method of compliance with FDEP 62640.600 and 40 CFR 503 regulations. Include details for transporting sludge from the dewatering equipment to the sludge process equipment, plus details for accepting sludge from other facilities. Also include the expected NPK values of the final fertilizer/soil amendment product. 8. Provide detailed list of equipment being provided. 9. Provide tentative project schedule indicating the number of days from Notice to Proceed until completion of construction with adequate time for permitting. For both RFPs, proposers were directed to utilize the same costs for electricity, diesel fuel, etc. In addition, proposers was directed to provide three quotes for all chemicals that would be utilized in their processes, and to utilize the average of the three quotes for each chemical in developing the anticipated annual cost of operations. Prior to issuing the RFPs, IWSD met with

Figure 2. Bioset Process Flow Diagram

January 2015 â&#x20AC;˘ Florida Water Resources Journal

representatives of other local municipal utilities regarding the possibility of developing a regional facility and with Collier County officials regarding expanding their current conditional use (zoning) to cover the sprayfield area. Expanding the conditional use proved to be a difficult process. Also, the other utilities could not commit to participating in the regional facility. Accordingly, IWSD decided to move forward with the turnkey DBF option for the IWSD sludge volumes only and reject all submittals received for RFP-2. In September 2012, IWSD evaluated submittals received for RFP-1. Schwing Bioset was selected due to the number of permitted installations it has in Florida, the experience of its design-build team, and its financial strength.

The Bioset Process This process consists of blending the sludge cake with quicklime and sulfamic acid and allowing the reaction to occur under pressure to meet the requirements of the stateâ&#x20AC;&#x2122;s Chapter 503 rule. To accomplish this, it was necessary to control the flow of the biosolids through the reactor and dose them with quicklime and sulfamic acid so that the retention time and temperature rise achieved within the reactor match the required temperature set forth by equation 2 in Chapter 503.32. Additionally, this dosage of quicklime raises the pH of the biosolids above 12, per Chapter 503.33. The final lime and sulfamic acid dosages for a specific application are designed such that U.S. Environmental Protection Agency (EPA) requirements are fulfilled for pathogen and vector attraction reduction, while also taking into consideration the local costs of chemicals. The goal is to strike the optimum balance between regulatory requirements and processing economies. Key features of the bioset process include: Totally enclosed o Contains dust o Contains odors Ideally suited to operate as a regional facility: o Accommodate fluctuations in percent solids of the incoming wet cake o Accommodate rapid increases and decreases in throughput o Accommodate biosolids from any wastewater process (aerobic, anaerobic, etc.) without any modifications to operations Fully automated o Chemical feed rate adjusted based on reactor temperatures for Phase 1 Long-term product stability o Regional facilities and fertilizer marketing

operations require product that is stable and can be stored for extended periods to span growing seasons and/or periods of unstable weather Easy to operate and maintain o Simple processes that do not require multiple shifts of operators or complicated and/or potentially dangerous operating conditions are generally preferred technologies Mixing Design Poor lime/sludge mixing is a problem observed with other lime stabilization systems where portions of unreacted lime can be found in the discharged cake. The bioset system uses a twin auger mixer with counter-rotating, intermeshing augers. Mixing continues with turbulence induced in the piston pump control valve housing. The thoroughly blended product can be seen with a homogeneous consistency and coloration. The homogeneous product is evidence that all the biosolids are uniformly treated and unreacted lime is not wasted. Dust Control Historically, biosolids treatment processes that use lime have been plagued by dusty conditions that create unpleasant working conditions for plant staff; even some of the original bioset process installations had these same issues. As a result, a common reaction to a proposed lime stabilization system is a knee-jerk negative response; however, controlling fugitive lime dust was recognized as one of the most important issues for a successful installation. With this in mind, great care has been made to ensure that the handling of lime does not result in dusty conditions. The photos in Figure 3 show equipment that illustrates the connections into the mixing hopper. All of the

Figure 5. Advanced High-Performance Screw Press

connections are either hard-piped or sealed with a flexible boot to ensure that lime dust cannot escape, and a clean working environment is provided. Odor Control Another common complaint related to biosolids treatment technologies that utilize lime is the associated odors. Some competitorsâ&#x20AC;&#x2122; systems and legacy bioset systems create overpowering amounts of unpleasant odors that have adverse impact on plant operations. As shown in Figure 3, this issue was addressed by completely enclosing the system where the mixing is taking place. The bioset reactor, a pressurized pipe, completely contains the

odors until they are released at the reactor discharge. This single-point location results in a strategic location to capture the odors. Also included is a pinch valve at the reactor discharge to flatten the sludge flowing out of the reactor to create additional surface area to allow the ammonia and other compounds to be released, and subsequently captured, and scrubbed under the collection hood. The resulting end product has an odor similar to wet concrete as a result of the lime content, which is not offensive. Typically, the first comment prospective customers make when touring a bioset installation is how clean the system is and the obvious lack of odors (Figure 4). Continued on page 24

Figure 3. Equipment Showing Connections in Hopper

Figure 4. Clean and Odor-Free Operation of Bioset Facility

Figure 6. Costs of Sludge Handling

Florida Water Resources Journal â&#x20AC;˘ January 2015

Continued from page 23

Figure 7. Product Analysis

Maintainability A remarkable feature of the bioset process is how little maintenance is required, as there are very few moving components. Aside from the two feed augers that require normal drive and bearing maintenance, the only other item that requires regular maintenance is the piston pump. The system uses piston pump technology; these pumps were originally developed for pumping concrete and have over the past 25 years been adapted to other industries. The basic pump models offered are designed for pumping concrete, essentially a mix of rock and sand, at operating pressures up to 1,500 pounds per sq in (psi). By anyone’s account, this is considered a severe duty application. When used in these applications, by comparison, the duty is much less severe, as biosolids will contain a small percentage of grit and the system will

Figure 8. Project Area Before Construction

Figure 9. Completed Facility (Small Footprint)

January 2015 • Florida Water Resources Journal

operate at less than 50 psi. As a result, the wear lives of the replaceable parts in the piston pump are capable of exceeding 5,000 hours of runtime. Screw Press Dewatering Process While there are many methods of dewatering municipal biosolids in wastewater treatment plants, screw press technology has emerged as a low-energy alternative to the historical technologies. Until recently, screw press technology has been unable to deliver dewatering performance capable of competing with these legacy technologies, thereby limiting their market appeal. A new high-performance screw press offers improved throughput, capture, and consistent high-dry solid content for the full range of capacities, providing wastewater plant operators with the features, benefits, and low-energy consumption expected from a screw press, with the performance similar to high-speed centrifuges. An advanced high-performance screw press (Figure 5) for high-solids cake offers a flexible dewatering solution for a wide range of facilities for digested and undigested biosolids. The precision machined screen and replaceable sealing lip produce high-solids capture rates with low power and wash water consumption. Wash cycles occur without interrupting the dewatering process, allowing greater uptime and dewatering capacity. This screw press offers simple start up and shutdown cycles, as well as having fully automatic and unattended operation. Financial Considerations Figure 6 shows the cumulative amounts the IWSD would have spent on sludge hauling (disposal) over the next few years compared to the capital and processing costs of running the bioset equipment (including chemical costs and electricity). The chart indicates a break-even point around the year 2019. Fertilizer License The IWSD further decided to obtain a bulk fertilizer license from FDACS. The IWSD had a staff competition to select the name for the product and the winning entry was Organi’Kalee. The IWSD’s FDACS fertilizer license was issued on Feb. 7, 2014. The IWSD utilized Thornton Laboratories to determine the guaranteed analysis of the fertilizer product (Figure 7) and will provide a copy of its label to purchasers of the product in accordance with FDACS rules. Construction of the facility is now completed, and IWSD began processing Class AA biosolids in April 2014 (Figures 8 and 9). Since the facility went into operation in April 2014, IWSD began to realize a significant savings in its annual cost of biosolids disposal.

FWRJ Looking for Articles and Column Information The Journal is always interested in receiving any technical or feature articles that deal with Florida water, wastewater, and operator issues to publish in the magazine. Each issue of the Journal has a theme, and the list can be found on the magazine’s website at www.fwrj.com, but articles on all topics are welcome. Subjects of interest include, but are not limited to, the following: utility management; water conservation and

SERVING FLORIDA S WATER AND WASTEWATER INDUSTRY SINCE 1949

December 2014

reuse; water and wastewater treatment; operator training; sustainability; biosolids; stormwater; distribution and collection systems; reclamation; financial issues; customer service; new facilities, ex-

pansions, and upgrades; energy efficiency; section, chapter, and regional activities; computer, information management, and technical issues; regulations; public involvement; and research.

The magazine’s News Beat column includes a company’s new personnel and promotions, organization and individual awards, and new projects. The New Products column highlights recent industry products. Send completed articles, article ideas, and column information to editor@fwrj.com. If you would like to discuss an article, contact the Journal editor, Rick Harmon, at 303-759-4966.

Florida Water Resources Journal • January 2015

Certification Boulevard

Test Your Knowledge of Wastewater Treatment Topics

Roy Pelletier 1. Given the following data, what is the solids loading rate on this secondary clarifier? • The plant influent flow is 15.5 mil gal per day (mgd) • The return activated sludge (RAS) rate is 65 percent of Q • There are two 120-ft-diameter secondary clarifiers • The aeration mixed liquor suspended solids (MLSS) is 3,200 mg/L a. 60.4 lbs/day/ft2 b. 8.6 lbs/day/ft2 c. 30.2 lbs/day/ft2 d. 15.5 lbs/day/ft2 2. Which is the highest life form in the activated sludge process: a free swimming ciliate, a stalked ciliate, or a rotifer? a. Free swimming ciliate b. Stalked ciliate c. Rotifer d. They are all the same. 3. What does the term “loading” refer to? a. Pounds of mixed liquor volatile suspended solids (MLVSS) under aeration b. Cu ft per minute (cfm) of air supplied to the aeration tank c. Pounds of carbonaceous biochemical oxygen demand (CBOD5) entering the aeration tank d. Amount of waste sludge removed from the system

4. Which condition may produce the best denitrification efficiency in an aeration tank? a. Low CBOD5 b. High aeration dissolved oxygen (DO) c. Low aeration DO d. Low waste activated sludge (WAS) rate 5. Which adjustment will create an increased contact time in the aeration tank? a. Lowering the weir b. Increasing the air supply rate c. Decreasing the WAS rate d. Decreasing the RAS rate 6. Which group of bacteria is responsible for conversion of inorganic ammonia in wastewater? a. Carbon eaters b. Methanogens c. Autotrophic d. Heterotrophic 7. What is the total length of weir for these secondary clarifiers? • Two secondary clarifiers • Each is 120 ft in diameter and 14 ft deep a. 1,507 ft b. 754 ft c. 377 ft d. 1,885 ft 8. What time of day will generally produce the highest DO in an unaerated stabilization pond? a. 12 midnight b. 6 p.m. c. 6 a.m. d. 12 noon

LOOKING FOR ANSWERS?

Check the Archives Are you new to the water and wastewater field? Want to boost your knowledge about topics youʼll face each day as a water/wastewater professional? All past editions of Certification Boulevard through 2000 are available on the Florida Water Environment Associationʼs website at www.fwea.org. Click the “Site Map” button on the home page, then scroll down to the Certification Boulevard Archives, located below the Operations Research Committee.

January 2015 • Florida Water Resources Journal

9. Given the following data, what is the velocity (ft per min) in this channel? • Flow rate is 1,500 gal per min (gpm) • The channel is 6 ft wide with a depth of flow of 15 in. a. About 27 ft per min b. About 17 ft per min c. About 35 ft per min d. About 13 ft per min 10. Which factor is the most important in maintaining efficient operation of a primary clarifier? a. Location of the tank b. Characteristics of the influent wastewater c. Number of operators in the facility d. Activated sludge solids retention time (SRT)

Answers on page 70

SEND US YOUR QUESTIONS Readers are welcome to submit questions or exercises on water or wastewater treatment plant operations for publication in Certification Boulevard. Send your question (with the answer) or your exercise (with the solution) by email to: roy.pelletier@cityoforlando.net, or by mail to: Roy Pelletier Wastewater Project Consultant City of Orlando Public Works Department Environmental Services Wastewater Division 5100 L.B. McLeod Road Orlando, FL 32811 407-716-2971

Florida Water Resources Journal â&#x20AC;˘ January 2015

FWEA CHAPTER CORNER Welcome to the FWEA Chapter Corner! Each month, the Public Relations Committee of the Florida Water Environment Association hosts this article to celebrate the success of recent association chapter activities and inform members of upcoming events. To have information included for your chapter, send the details via email to Suzanne Mechler at MechlerSE@cdm.com.

Suzanne Mechler

Southeast Chapter Holds Quarterly Meeting and Learns About University Of Miami Net-Zero Water Project Amy M. Baricevich n Nov. 18, 2014, the Southeast Chapter hosted its fourth quarterly meeting at the Wyndham Deerfield Beach Resort. The chapter president, Wisler Pierre-Louis, opened the meeting with the following announcements: The chapter held a very successful young professionals event on Sept.18, 2014, at the Funky Buddha Brewery in Oakland Park. He noted that everyone who attended enjoyed a great event. Another young professionals event is being planned for this year. The Southeast Chapter held a Wastewater Process Seminar on Nov. 6, 2014. Eric Stanley spoke briefly about the success of the event, which was held in Boca Raton. The next quarterly meeting will be in March.

Net-Zero Water Project The speaker for the evening was Dr. James Englehardt, Ph.D., P.E., from the University of Miami. Dr. Englehardt is a professor in the department of civil, architectural, and environmental engineering, and he gave a presentation on the University of Miami’s autonomous net-zero water project. Dr. Englehardt discussed how typical treated wastewater in South Florida meets 87 of the 93 drinking water requirements. Most of the treated wastewater is then disposed of into the ocean or deep aquifers, which subsequently increase impurities. This sparks the question of how to save energy and reuse the treated water. The net-zero water project is a research project funded by the National Science Foundation that evaluates technologies to take buildings off the water grid without raising the cost of high-quality water. Dr. Englehardt discussed how this is being tested at a four-bedroom university apartment that has been modified to include a net-zero treatment facility, cistern rainwater col-

lection, and separate city water supply for drinking and cooking. The low-energy treatment system at the apartment incorporates biological treatment, iron-mediated aeration/vacuum ultrafiltration, and peroxone advanced oxidation with rainwater makeup to treat wastewater from the showers, toilets, sinks, and laundry, avoiding the use of high-energy membrane treatment. The project collects data to study the process development and optimization. In addition, psycho-cultural studies are being conducted to develop an understanding of factors driving the acceptance, and sometimes lack of acceptance, of net-zero water technology. Finally, machine learning and evidence processing techniques are being developed to detect risk in real time based on continuously monitored water quality parameters. More information on the project can be found on its website: http://www6.miami.edu/netzerowaterdorm/index.html. Amy M. Baricevich, P.E., is with CDM Smith in West Palm Beach.

Happy New Year from the Manasota Chapter! Samantha Nehme

Mike Knowles, Manasota Chapter vice chair, assists a participant with the World Water Monitoring Day kits at the Sarasota Bay Water Festival.

January 2015 • Florida Water Resources Journal

As 2015 begins, I want to reflect on 2014 and review how the Manasota Chapter has been active in the community and the events we’re planning for the year ahead. From the community-based gatherings that raised money and awareness for great causes to the quarterly luncheons where presentations were given to a roomful of water and wastewater professionals, there was never a dull moment for the chapter. In recent news, our chapter represented FWEA at the Sarasota Bay Water Festival on No-

vember 1. The event was held to celebrate the importance of Sarasota Bay to the region’s environment, economy, and quality of life. At the FWEA exhibitor booth, our members assisted children and adults in performing tests of pond water for dissolved oxygen, pH, and turbidity using the World Water Monitoring Day kits. It was a lot of fun with games, live music, delicious food, and raffles! Our chapter had a great time being a part of the event and is looking forward to the festival next year. A big thank you to Kristiana Dragash, Lindsay Marten, Mike Knowles, Mike Jankowsi, Kyle Kellogg, and Mike Nixon for taking time out on a Saturday to volunteer at the event! We also had a great chapter presence at this year’s Water Environment Federation Technical Exhibition and Conference (WEFTEC). Kristiana Dragash, our director at large, presented a session entitled, “Planning, Why Bother? Just Let the Reuse Flow,” which featured presenters from North Carolina, California, and Australia. The presentations highlighted the vast difference in reuse through the United States and the world. While our steering committee has grown throughout 2014, we have also seen members move up within the organization at the state level. Danielle Bertini was recently appointed as chair of the Student and Young Professionals Committee. Congratulations, Danielle! The last luncheon of the year was held on November 4 at our new location, the Sarasota County Operations Center. The speaker, Andy Burnham with Burton and Associates, discussed high-level ratemaking. The presentation identified best practices to develop rates that provide sufficient revenue to meet the financial requirements of a utility system in environments of declining demand. The presentation also discussed the development of specific rate structures that reflect a community’s unique blend of other common ratemaking objectives. We had a great turnout of water and wastewater professionals! The holiday social was held on December 18 at Evie’s Tavern on Bee Ridge Road. It was a joint professional society event with the local chapters of the American Water Works Association, Florida Engineering Society, American Public Works Association, and American Society of Civil Engineers, and a great time was had by all! Last year was packed with exciting events! On behalf of the FWEA Manasota Chapter, we would like to thank all of the participants, volunteers, presenters, and sponsors for making these events possible. Keep your eyes and ears open for more great opportunities and occasions to come in 2015! Samantha Nehme is an engineering intern at Stantec in Sarasota. Florida Water Resources Journal • January 2015

F W R J

Don’t Pass on the Gas: More Bang for Your Biogas Buck Matthew Munz and Bruce Petrik n June 2013 the City of Tampa retained MWH to evaluate the production and utilization of biogas at the City’s Howard F. Curren Advanced Wastewater Treatment Plant (AWTP). Its study included a detailed analysis of current biogas quantity and quality, a condition assessment of the current biogas handling facilities, an investigation of environmental regulations affecting the biogas cogeneration at the facility, and an economic analysis comparing various biogas utilization alternatives. The AWTP is permitted for 96 mil gal per day (mgd), with current flows averaging between 50 and 60 mgd. The biosolids handling facilities include gravity thickening of the waste activated sludge (WAS), anaerobic digestion, dewatering using belt filter presses, and sludge drying facilities for the Class AA end product. The digester gas from the anaerobic digestion process is used for mixing the digesters, cogeneration, and firing boilers for the digestion heating process during the winter months. The hot water from the engine’s cooling system is used as the primary heating source for the di-

gestion system. The biosolids dryer facility consists of two rotary drum dryers that use natural gas as fuel. Currently, the drying system is not operational and the dewatered sludge cake is hauled from the site for land application.

Objectives The objectives of the study were to develop a business case for the continued utilization of biogas, provide operational enhancement recommendations, and present the potential cost savings associated with the recommendations. In order to meet these objectives, several tasks were completed, including: Analysis of current biosolids and biogas production Condition assessment of existing biogas handling system Evaluation of energy production and requirements Evaluation of environmental regulations Development of biogas utilization alternatives Economic analysis of preferred alternatives

Figure 1. Digester Loading, 2005-2011

Matthew Munz, E.I., is an associate civil engineer and Bruce Petrik, P.E., is principal wastewater leader with MWH Global in Tampa.

January 2015 • Florida Water Resources Journal

Current Biosolids and Biogas Production The AWTP currently operates as a highpurity oxygen (HPO) facility with primary sedimentation, carbonaceous reactors, nitrification reactors, denitrification filters, and disinfection facilities. The current biosolids handling facilities include a thickening step for WAS, mesophilic anaerobic digestion for sludge stabilization, dewatering facilities, and a sludge drying facility. The WAS comes from carbonaceous reactors and is pumped from the plant pump station to two gravity thickeners for sludge thickening. Thickened WAS and primary sludge are pumped to a common wet well before being introduced to the anaerobic digesters for Class B sludge stabilization. The digested (stabilized) sludge is dewatered and then either hauled off site for land application or dried to produce a Class AA biosolid product. Plant data from January 2005 to December 2011 was reviewed in an attempt to better understand the facility’s overall treatment process and the biosolids produced. The liquid treatment process, and the sludge produced from those processes, affects the quality and quantity of the biosolids produced and must be considered when determining potential biosolids project alternatives utilizing gas production. Historical sludge flow quantities, as well as volatile solids (VS) loadings to the anaerobic digesters, are shown in Figure 1.The average VS loading rate is approximately 125,000 lbs/day and the average sludge flow is roughly 396,000 gal per day (gpd). A slight downward trend in production is noted from 2005-2011 and equates to an approximately 34 percent reduction over that time frame. Based on conversations with the Continued on page 32

Continued from page 30 City, this trend is not expected to continue and sludge production will stabilize, and may increase, based on wastewater flow projections due to population growth. Figure 2 shows the reported quantity of total monthly biogas produced from 2005 to 2011. The graph shows a downward trend (30 percent drop) in biogas production over the last seven years. The average value dropped from 27.8 mil cu feet (mcf) per month to 21.9 mcf. It is important to note that even though there are three gas meters at the engine building, none of these meters are used to measure biogas flow. The City indicated that the biogas production is calculated based on the engine runtime. Each engine has a known fuel (biogas) consumption rate. This value is multiplied by the total runtime during the day to estimate the biogas produced per day.

The reported downward trend in biogas production has two main contributors, with one being that the downward trend correlates with the reduced sludge loading, as shown in Figure 1. In addition, there is a leak in the engine jacket water piping that requires the City to run the biogas-fueled hot water boilers to make up the hot water that has leaked. This would have diverted biogas from the engines and caused a decrease in the reported biogas production, as biogas production is calculated based on engine runtime. The City is currently replacing the leaking engine jacket water pipe. In order to establish the quality of the biogas produced, samples were taken of the gas and tested for major gas constituents, gross heating value, siloxanes, sulfur compounds, and volatile organic compounds. Samples were taken from the biogas system both upstream and downstream of the existing filter units in order to provide the City with infor-

mation on how well the current biogas conditioning system operates. Table 1 presents a summary of testing results that were used to determine biogas quality and potential treatment options when utilizing biogas in cogeneration engines. The concentrations shown in Table 1 for the biogas upstream of the existing filters at the AWTP are very typical of anaerobically digested wastewater sludge. The methane concentration of 54.4 percent is slightly lower than the typical 60 percent. The lower methane content leads to a slightly lower heating value as well; the 550 British Thermal Unit (BTU)/ft3 value reported is under the industry standard of 600 BTU/ft3. Table 1 shows that hydrogen sulfide and siloxane concentrations are higher downstream of the biogas filter units; this increase in concentration is caused by what is called the â&#x20AC;&#x153;rolloverâ&#x20AC;? effect. The filter units purge sulfur compounds (hydrogen sulfide) and siloxanes, which have smaller molecular weights as they fill with the siloxanes that have high molecular weights. This purging creates higher concentrations of siloxanes and hydrogen sulfide downstream of the existing filter units.

Current Biogas Handling and Utilization

Figure 2. Biogas Production, 2005-2011 Table 1. Biogas Testing Results

Inspections were conducted of all of the biogas handling equipment, including storage, conveyance, treatment/conditioning, and cogeneration. The biogas produced is stored in the floating, gas-holder-type covers on digester Nos. 1 through 4. This limited storage capacity is used to build biogas reserves during nonpeak hours so that the maximum electricity production is done during peak hours, when electricity is more valuable. The biogas is conveyed through sediment traps for moisture removal and then flows through biogas conditioning filters. After passing through the conditioning filters, biogas is pressurized by rotary positive displacement compressors where it is discharged through a common header to the cogeneration engines.

Table 2. Existing Cogeneration Engine Specifications

January 2015 â&#x20AC;˘ Florida Water Resources Journal

Table 3. Biogas Energy Calculations

The AWTP currently has five cogeneration engines. Table 2 lists the specifications for each of the engines. Waste heat is recovered from the engines and used to provide heat to the anaerobic digestion system. Mounted on each of the five engines are heat exchangers to transfer the waste heat from the engine to the jacket water loop to provide heat to the digesters. In the event that additional heat is needed for the digestion system, there are four biogas-fueled water boilers integrated into the heating loop. Primary concerns with the current biogas handling facilities are centered on the biogas treatment system and the aging cogeneration engines. The current biogas conditioning system is highly inefficient, as supported by the biogas testing results. Operations staff has complained about the quality of the biogas used to fuel the engines; excessive moisture, white deposits on the engine pistons (siloxanes), and corrosion have been observed on the engine system. It was recommended that a new biogas conditioning system targeting hydrogen sulfide, moisture, and siloxanes be installed. The biogas-fueled engines are old and in need of repair and/or replacement. Engine No. 1 is out of service and in need of major repairs and the City indicated that the estimated repair costs for this engine is $100,000. Engine Nos. 2, 3, 4, and 5 are currently in operation. Engine operators have indicated that the maintenance of these biogas-fueled engines is very labor intensive and time-consuming due to the poor condition of the engines. Engine operators have reported that the engines require oil replacement every 500 hours; as a comparison, the engine operations manual indicates that the oil should be replaced every 1,500 hours. Additionally, the sludge drying facilities are unoperational and it is unclear if the City will be making the necessary investment to repair sludge drying facilities as the hauling of Class B solids is a suitable disposal method at this time.

Table 4. Heat Energy Demands

Figure 3. Heat Energy Available Versus Heat Energy Required

Energy Production and Requirements Using the biogas testing results, the amount of energy available in the biogas created was calculated. These calculations are shown in Table 3. The primary demand of energy associated with the anaerobic digestion process comes from the heat required to maintain digester temperatures. The heat energy demands for the anaerobic digestion system are summarized in Table 4. The total energy required to maintain and operate the digestion system is approximately 7,981,952 and 4,274,987 BTU/hr during the winter and summer months, respectively. Figure 3 shows the biogas heat energy available versus the seasonal digester operational heating/energy demands.

Environmental Regulations The AWTP currently has a Title V air operation permit (Permit No. 0570373-018-AV) granted by the Environmental Protection Commission (EPC) of Hillsborough County. The Title V permit will expire on Nov. 1, 2016. The City was concerned that language in its current air permit would require that the ex-

isting cogeneration engines be replaced in order to operate in compliance with its permit past October 2013. The current air permit states that the existing engines must comply with the emissions standards of 40 Code of Federal Regulations (CFR) Subpart ZZZZ by Oct. 19, 2013. The consultant spoke with air-permitting staff at the Florida Department of Environmental Protection (FDEP) and determined that there are no emissions standards in Subpart ZZZZ that would apply to the Cityâ&#x20AC;&#x2122;s existing biogas-fueled engines. Subpart ZZZZ only outlines maintenance requirements for existing, nonemergency, digester-gas-fueled engines and the City is already in compliance with these requirements. This means that under current regulations, the Cityâ&#x20AC;&#x2122;s existing engines can be run indefinitely. This would also apply to any future renewals of the air permit as long as current regulations remain in effect. There is currently no regulatory need to update the cogeneration system.

Development of Biogas Utilization Alternatives As indicated in Figure 3, there is heat energy available in the biogas produced at the Continued on page 34

Florida Water Resources Journal â&#x20AC;˘ January 2015

Continued from page 33 AWTP. The City is currently utilizing some of this energy to produce electricity; however, concerns about the operational costs of the engines, new regulations, and the age of the existing equipment have led the City to evaluate alternatives for the utilization of the biogas. Alternative methods of biogas utilization were presented to the City based on the following considerations: Financial benefits (business case) Beneficial use of existing equipment Amount of energy provided Site constraints Technical viability Operational issues Six alternatives were developed and presented to the City in an initial screening workshop. Alternative 1 - Replace the five existing biogas engines with three new 1000-kilowatt (kW) combined heat and power (CHP) engines located in the existing generator building. Heating needs in the anaerobic digesters would be met by heat recovered from the three new CHP engines. Alternative 2 – Similar to Alternative 1, with the addition of absorption chillers to provide heating and cooling to the facility’s buildings. Alternative 3 - Replace the five existing

500-kW engines with three new 1000-kW CHP engines located in an existing building adjacent to the dryer facility, allowing for engine exhaust to be used to supplement natural gas requirements in the dryer facility. Heating needs in the anaerobic digester would be met by hot water recovered from the dryer facility. Alternative 4 - Replace the five existing biogas engines with three new 1000-kW CHP engines located in the existing generator building and construct a new dryer facility located near the digesters. This would allow waste heat from the cogeneration engines to be used in the new dryer facility. Alternative 5 - Eliminate the five existing 500-kW engines and route all of the biogas to the existing dryer facility. Heating needs in the anaerobic digesters would be met by hot water recovered from the dryer facility. Alternative 6 – Similar to Alternative 5, this would eliminate the existing cogeneration engines, but also require the construction of a new dryer facility near the digesters to allow for easier conveyance of the biogas to the new dryer facility. Heating needs in the anaerobic digesters would be met by hot water recovered from the dryer facility.

During the initial screening workshop, it was determined that Alternatives 1, 3, and Table 5. Economic Analysis Parameters 5 would be further evaluated in an economic analysis. In addition to these three alternatives, the City requested that two additional alternatives be included in the economic analysis for comparison purposes:

Table 6. Economic Analysis Summary (Dryer Facility Inoperable)

January 2015 • Florida Water Resources Journal

Alternative 5a - Eliminate the five existing 500-kW engines and use biogas to meet the heating needs of the anaerobic digesters. Any excess biogas would be routed to the existing dryer facility to offset natural gas use. Alternative 7 - Eliminate the five existing 500-kW engines and fuel the digester boilers with biogas and flare the excess biogas. A number of other biogas processing and utilization options are available in the marketplace, but were not considered feasible. Some of these alternatives are: Fueling fleet vehicles - Some municipalities have constructed gas stations for their municipal fleet using biogas as fuel. Although this alternative is an environmentally conscious alternative, the capital expenses, the complex logistics, and difficulty in operations represent a challenge to the City. In addition, the biogas needs to be treated and cleaned to very stringent fuel characteristics; biogas is high in carbon dioxide and hydrogen sulfide, which must be removed before the gas is burned in vehicle engines. Exporting biogas to other Tampa port users Although the AWTP is located near the port in Tampa, with easy access to trains and freight carriers, no other port user has been identified with the need for biogas. Researching other biogas users within the area was out of the scope of this study. However, it is important to note that the AWTP has a need for use of the biogas generated, as illustrated in this section. It makes more sense to the City to utilize the biogas in its facility prior to considering selling it to other outside users. Microturbines - Microturbine manufacturers were consulted to determine the feasibility of using their equipment. The largest Continued on page 36

Table 7. Economic Analysis Summary (Dryer Facility Repaired)

Continued from page 34 microturbine engine available in the market is 250 kW. Based on current evaluation assumptions, microturbines would not be cost-effective to install because of the large amount of units needed. In addition, microturbines require more stringent fuel characteristics; the cost for cleaning the biogas to microturbine fuel characteristics is more expensive than cleaning it to engine characteristics. Fuel cells - The fuel cell technology, although very promising, has not been fully developed. At this time, itâ&#x20AC;&#x2122;s uncertain if this new technology is adequate for the City. In addition, implementing this new technology will mean training, or possibly adding, new skilled operators dedicated to this type of system.

Economic Analysis To further evaluate the five preferred alternatives, an economic analysis that included capital and operational and maintenance costs was conducted. This analysis allows for the five alternatives to be compared in order to determine the most economically beneficial alternative. Parameters for conducting the economic analysis are outlined in Table 5. At the request of the City, two scenarios were evaluated for each of the alternatives; Scenario 1 assumed that the dryer facilities remain

offline, while Scenario 2 assumed that the dryer facilities were repaired and operational. The economic analysis conducted presents annualized costs and benefits for each of the preferred alternatives. These annualized values allow for inflation and the time value of money to be considered. In order to calculate the annualized values, costs and revenues for each alternative were estimated for fiscal year 2012 and then increased by the specified inflation rate of 2.5 percent over 20 years to coincide with the capital-cost amortization period. These annual costs were then equated to a net present worth, which was annualized over the same 20-year period using a 5 percent interest rate. Table 6 presents a summary of the economic analysis considering that the dryer facilities are not repaired and Table 7 summarizes the economic analysis considering that the dryer facilities are operational.

Conclusions As shown by the results of this study, there is a very realistic business case to be made for the continued utilization of biogas at the AWTP. While the economic benefits of biogas utilization are reduced due to the age of the biogas facilities and equipment, they are still present and should not be overlooked. The conclusions reached as a result of this study include the following:

Alternative 1 provides the greatest net benefit if the dryer is out of operation, largely because of the revenue generated from increased electricity production. Alternative 3 has the greatest net benefit if the dryer is operational because it produces the same amount of electricity as Alternative 1, as well as offsets natural gas use in the dryer. Regardless of the operational status of the dryer, Alternative 1 provides a $425,019 increase in net benefit over the current system. Alternatives 5, 5a, and 7 have the lowest net benefit in both dryer operational scenarios, and are considered impractical for the following reasons: o Flaring provides the lowest annual net benefit as there is no electricity production and natural gas offset is minimal. o Flaring does not utilize all of the stored energy in the biogas, a readily available resource at the plant. o Producing electricity is more advantageous and economical than offsetting or supplementing natural gas based on current energy prices. The current biogas filter units are not providing any benefit to the City and may actually degrade the quality of the biogas produced at the plant. This has greatly increased the required maintenance costs to operate the existing cogeneration engines.

Recommendations

Figure 4. Comparison of Recommended Project and Current System

January 2015 â&#x20AC;˘ Florida Water Resources Journal

It was recommended that the City replace its current biogas conditioning system in the next one to two years. As was discussed, the current filter units are not providing any benefit to the City and may actually degrade the quality of the biogas produced. The costs of a new biogas treatment system have been included in the capital cost estimate of this recommendation. It was also recommended that the City replace its five existing biogas-fueled engines with three new 1,000-kW engines. New engines will reduce maintenance costs and will increase revenues due to greater efficiencies in engine design. Alternative 1 is the most cost-effective, feasible alternative for the City. These improvements can be phased in over the next 20 years. In order to demonstrate the financial benefit of this capital investment, the recommended alternative was compared to the current engine operation. Figure 4 shows the capital cost, labor cost, materials cost, revenues, and net benefit for both Alternative 1 and the current system annualized over the 20-year capital amortization period.

Florida Firm Receives Chamber of Commerce Recognition

Left to right are: Lawson Brown, Duval School principal; Buford Davis, landscape architect for the project; and Jones Edmunds founders and directors, Dick Jones and Bob Edmunds.

January 2015 â&#x20AC;˘ Florida Water Resources Journal

Jones Edmunds, an engineering and environmental sciences consulting firm that has seven offices throughout Florida, has been recognized by the Gainesville Area Chamber of Commerce as the Best Overall Business for 2014. The firm, which has been involved in community projects since 1974, was cited by the Chamber for its core values of integrity, knowledge, and service, and for local projects that showcase the Gainesville region at statewide conferences. As an example of its commitment to the community, Jones Edmunds employees were out on a recent Saturday morning to take the lead on a beautification service project at Duval Elementary School. Parents of students and other community leaders worked to improve the curb appeal of the school, which is near the firmâ&#x20AC;&#x2122;s Gainesville headquarters.

Florida Water Resources Journal â&#x20AC;˘ January 2015

Evaluation of a Composting System Using Sludge From Wastewater Treatment Plants Hector G. Avilan Wastewater treatment plants are an integral part of a community. They provide treatment and disinfection of wastewater for residences, businesses, and industries. After a long process, sludge (biosolids) is produced, to be used in an environmentally acceptable manner as a beneficial and valuable fertilizer and soil conditioner. The best way to use the sludge or biosolids from wastewater treatment plants is through a suitable composting process. The combination of naturally occurring beneficial microorganisms, enzymes, and botanical products (BMEBP) obtained from the air, land, and water enhance the composting process and could improve the use of biosolids for fertilizer. Any products used in the process should be generally recognized as safe (GRAS) material and be pathogen-free.

The mixing of biosolids with other city waste material, such as yard waste and the addition of BMEBP, was used in conjunction with a management process within the composting facilities of West Palm Beach County.

Biosolids Defined Land Application of Biosolids Biosolods are defined by the U.S Environmental Protection Agency (EPA) as nutrient-rich organic material resulting from the treatment of domestic sewage sludge in a treatment facility. When treated and processed, these residuals can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth. There are two types of biosolids: Class A: Biosolids containing no detectible levels of pathogens. Class B: Biosolids are treated, but still contain detectible levels of pathogens. About 8 mil dry metric tons (MT) of biosolids were produced last year in the United States. Approximately 55 percent of the total biosolids generated each year are land-applied,

and the remainder were either incinerated or processed for energy recovery, compost, or landfill. The EPA estimates that biosolids are applied to approximately 0.1 percent of available agricultural land in the U.S. on an annual basis.

January 2015 â&#x20AC;˘ Florida Water Resources Journal

The benefits of land application include: Can be used as a soil conditioner. Improves physical, chemical, and biological properties of soil, especially degraded or disturbed soils. Acts as a food source for microorganisms; organic material is the major binding agents for aggregate formation and stabilization. Reduces soil erosion. Yard waste refers to waste resulting from maintenance or removal of vegetation, including but not limited to brush, branches, leaves, flowers, shrubs, and small trees. After itâ&#x20AC;&#x2122;s processed, the waste is taken to landfills or it becomes compost and mulch.

Composting Composting is a biological process of breaking up organic waste such as food waste, manure, leaves, grass trimming, paper, worm, coffee grounds, etc., into an extremely useful humus-like substance by various microorganisms including bacteria, fungi, and actinomycetes in the presence of oxygen. The most important parameters for composting are: Temperature Moisture Content Aeration pH Carbon-to-Nitrogen (C:N) Ratio Time Temperature - Between 130°F and 160°F; the initial temperature could reach up to 160°F. Many pathogen microorganisms are killed. • Windrow Composting: 130°F for at least 15 days with five turns • Aerated Static Pile or In–Vessel: 130°F for at least three days Moisture - Optimum content is 35–65 percent. Moisture that is too high results in fermentation, putrefaction, and odors; if it’s too low, there is dust, charring, fire, and nuisance fungi.

Figure 1

Aeration - Reduces high temperature; the main method is turning the compost. Aerobic organisms need to breathe air to survive. Aeration is also useful in reducing high initial moisture content in composting materials. Turning the material is the most common method of aeration when composting is done in stacks. Hand turning of the compost in piles or in units is most commonly used for small garden operations. Mechanical turning is more economical in large municipal or commercial operations. Carbon-to-Nitrogen (C:N) Ratio - The microorganisms need more carbon than nitrogen. If there is too much carbon, decomposition slows when the nitrogen is used up and some organisms die. The optimum values are 20-30:1. pH - The measure of the acidity or alkalinity of soil, with 7 pH considered neutral. Numbers below and above 7 acidity are alkaline. If the material has begun putrefying before being received for composting, the pH will be near the lower value since anaerobic organisms produce acids. When the initial pH is between 6 and 7, the pH of the composting material may drop a little during the first two or three days of aerobic composting, which is also due to the formation of acids. Time - The time required for satisfactory stabilization depends primarily upon initial C:N

ratio, particle size, maintenance of aerobic composition, and moisture content. The advantages of composting include: Lack of availability of landfill space for solids disposal Emphasis on beneficial reuse at federal, state, and local departments Addition of biosolids compost to soil increases soil’s phosphorus, potassium, nitrogen, and organic carbon content The disadvantages include: Odor production in composting site Survival and presence of primary pathogens in the product

A Sustainable Bioaugmentation System Through some extensive research and studies, a product has been developed that is changing how the wastewater industry handles biochemical oxygen demand/chemical oxygen demand (BOD/COD), sludge, compost accelerations, odor, and other problems that wastewater treatment facilities deal with on a daily basis. The product is an all-natural botanical Continued on page 42

Figure 2 Florida Water Resources Journal • January 2015

Continued from page 41 blend that seems to be nontoxic, environmentally safe, and meets or exceeds federal, state, and local government standards. This natural mix compound has proven to be effective in many wastewater treatment facilities across the Southeast, with both domestic and industrial wastewater. It is being used in lift stations, high-pressure sewer cleaning equipment, compost accelerations, and landfill applications. It has also proven to be more economical in wastewater treatment than conventional chemicals, bacteria/enzymes, and physical treatments. The mix is compounded by: Beneficial microorganisms Enzymes Botanical product extract Beneficial microorganisms - Bacillus and Lactobacillus microbial strain, at a rate of 4 bil colony-forming units (CFU). Enzymes – Includes protease, amylase, lipase, and cellulase. Botanical product extract: Includes yucca schidigera, which controls odor, ammonia, and other gas emissions, and has a surfactant effect. The characteristics of these three compounds include: All microorganisms are from natural origin, not genetically manipulated or engineered Nonpathogenic and nontoxic Aerobic, anaerobic, and facultative microbes Natural botanical extracts and enzymes All organic All are GRAS by Food and Drug Administration (FDA), Section 21, CFR 184

Evaluation of Composting Versus Composting With Mix Product The new compost was made using the same process used in the Palm Beach facility, plus the mix, which was then compared with the compost control made in the same facility without the mix.

Figure 3

Procedures Materials: A reactor bay (252 ft long x 6.5 ft x 6.5 ft) Compost turner Biosolids: 46 MT Yard waste: 46 MT Mix product: 2 gal Water 1. Apply 1 gal of the mix uniformly to the 92 tons of mixed material the first day. 2. The gal should be previously diluted in nonchlorinated water at the ratio of 1:19. 3. Apply the resulting 20 gal of the mix uniformly to the 92 tons of mixed material. 4. Repeat the same procedure at the third week. There should be a daily control of temperature and moisture of the composting material, and all the regular observations that are usually applied to the product in its different stages are made. It’s recommended to always apply the same parameters during the process; for example, the temperature should be between 140160°F, and the moisture should be at 50 to 60 percent

After comparison, the following results were received from the Pennsylvania State University laboratory: Control Compost - These numbers are from the normal compost and all values are between the normal parameters, although the compost was processed for only two weeks (Figure 1). Mix Product - In this report, the levels of ammonia and the solids amount have lowered, and the organic matter has kept its values. Also, the nitrogen lowered its value, and the C:N ratio is closer to optimum values (Figure 2). The percentage of organic matter in solid amount (72 percent) and the percentage of moisture (28 percent) are shown in Figure 3. The organic matter is kept, and the solid amount is reduced around 10 points (Figure 4). There needs to be a differentiation between organic matter and organic material, as they both are used for different purposes. Organic material is used to make compost (garden waste, yard waste, leaves, woody material, grass, and animal remains), and it conforms the solids. Organic matter, on the other hand, is decomposed organic material.

Measurement Parameters These parameters should be used to compare a compost control and the new compost: pH Solids Moisture Organic matter Total nitrogen Organic nitrogen Ammonium (NH4-N) Carbon C:N Phosphorus (P2O5) Potasium (K2O) Calcium (Mg) Fecal coliform

C:N Ratio The control compost has a slower stabilization of 12:1. The mix product has a faster stabilization of 18:1. The optimum C:N ratio is 20-30:1. If the relation is less than 20, it could produce ammonia gas, which not only harms the environment, but also worsens the quality of the compost. The mix compost, despite being younger, has a ratio that is closer to optimum values. Level of Ammonium The reduction of the ammonium level is relevant in the mix compost (Figure 5). Continued on page 44

Figure 4

January 2015 • Florida Water Resources Journal

Figure 5

Continued from page 42

Conclusions The following determinations were made: Despite being an immature compost (two weeks), the C:N ratio is very close to normal standards. The levels of ammonium are much lower than the control, resulting in a compost with no foul odor. The nitrogen obtained is of better quality,

and it is useful for land application. The C:N ratio was higher than the control. There was a visible decrease of flies. In less amount of time, the mix compost had better qualities as fertilizer. There was a decrease of solids. The levels of organic matter were kept. The mix accelerates the compost process, resulting in a better quality compost in less time. The following suggestions were also made:

Solid Waste - In this study, solid waste was not used as a bulking agent, but it could be a very good alternative for a community. The compost could be controlled in its chemical composition, improving the quality of the nitrogen/phosphorus/potassium (NPK) relation. Organic Fertilizer - Controlling the bulking (yard waste, solid waste, and other organic wastes) could result in, not a compost, but an organic fertilizer capable of supplying the necessities for crops, gardens, nurseries, etc., leaving behind the use of inorganic fertilizer, which can cause damage to the ecosystem. Also, this could decrease the expenses for municipalities and allow them use more garbage for raw material. The aim of this study is to improve the physical, chemical, and aromatic aspects of the composting material being produced at several wastewater treatment facilities, but also focus on obtaining an organic fertilizer that will be able to substitute partially harmful inorganic fertilizers, preventing environmental pollution and contamination of air, soil, and water. The new fertilizer obtained in this process would help diminish the contamination of underground aquifers by changing the chemical form of phosphorus, one of the most damaging contaminating elements, into organic acids, which are better absorbed by the plant rooting system, leaving less free inorganic phosphorous to contaminate the underground water.

References • Biosolids Technology Fact Sheet, Use a Composting for Biosolids Management. U.S. EPA. • Sewage Sludge Biosolids, Frequently asked questions. U.S. EPA. • Land Application of Biosolids in the U.S.A.: A Review. Qin Lu, Zhenli L. He, and Peter J. Stoffella. • Question and Answer on Land Applications of Biosolids. Water Environment Federation. Hector G. Avilan is general director with CoinVet Inc. in Hialeah.

January 2015 • Florida Water Resources Journal

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Utilities Maintenance I & II ............................................$225/$255

Backflow Tester Recertification ......................................$85/$115

Wastewater Collection System Operator C, B & A ......$225/$255

Basic Electrical and Instrumentation ............................$225/$255

Water Distribution System Operator Level 3, 2 & 1 ......$225/$255

Facility Management Module I......................................$275/$305

Wastewater Process Control ........................................$225/$255

Reclaimed Water Distribution C, B & A ........................$225/$255 (Abbreviated Course) ................................................$125/$155

Wastewater Sampling for Industrial Pretreatment & Operators................................................................$160/$190

Stormwater Management C & B ...................................$260/$290

Wastewater Troubleshooting ........................................$225/$255

Stormwater Management A .........................................$275/$305

Water Troubleshooting ..................................................$225/$255

For further information on the school, including course registration forms and hotels, download the school announcement at www.fwpcoa.org/fwpcoaFiles/upload/2015SpringSchool.pdf

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FWPCOA Training Office 321-383-9690 Florida Water Resources Journal • January 2015

LEGAL BRIEFS

Fees and Flying Meter Covers Gerald Buhr Martin County Woman Badly Injured by Flying Water Meter Cover It has been reported that a Martin County woman was badly injured with lifethreatening injuries when a county maintenance crew ran over a steel meter cover with a lawn mower, breaking it into a sharp projectile. The cover hit the woman in the head while she sat in her car. This occurred in July, and I could find no official statement of her condition; however, the Martin County Sheriff ’s Office Facebook timeline did have a final comment by a well-wisher who was glad to see she was “back home and doing well.” I truly hope she has recovered, and that all this is behind her. I recall when I was at a Boy Scout camp (many, many years ago), the person mowing a lawn with a commercial mower stopped when I got too close and told me (actually, he yelled

at me) never to pass by a commercial mower because it could throw a stone at the speed and impact “of a .22 rifle bullet.” It certainly appears from the reports that this poor woman was innocently minding her own business when she was so severely struck. If commercial mowers are that dangerous, hopefully, the utility and/or the mowers are considering the consequences. At some point, it will be necessary for somebody to evaluate the cause of the accident, at least for future safety concerns, if not for litigation purposes. I do not have nearly enough facts to assign blame to anybody, nor would I care to do so, but some things a person could consider for future public safety are: Was the meter cover properly secured to the meter box? If so, was the meter cover properly closed? Was the meter box placed too high relative to the surrounding grade of the soil such that running it over would cause it to be too close to the blade? Was the mower in an area suitable for such commercial mowers to operate? If any of those questions were answered “no,” then was that condition observable to the person mowing? Negligence is loosely de-

fined as the failure to use the reasonable care necessary in a given situation, and that is what a court will consider. Hopefully, the members of our industry, for safety’s sake, use much more care than what is simply “necessary,” and I am sure the majority do. But if you want a shock, go to Google and look up “meter box injuries” and see how many alleged incidents are reported in the news; then, consider how many more are not reported. Source: CBS 12 News, story by Victoria Price; and https://www.facebook.com/MartinCountySheriffsOffice/photos/a.316726388337911.87592.309649 922378891/820095614667650/.

Judge Approves Fruitland Park Settlement Over Improper Utility Fees It has been reported that a judge has approved an amount of $530,000 to be paid into a settlement account by the City of Fruitland Park. It was alleged that the city had imposed an additional $8 fee on water and sewer bills to pay for police and fire charges. The court allowed the attorney fees and costs of $255,000, and awarded the primary (named) class members $1,200. The remaining utility customers got around $270,000 to be split among that class, amounting to roughly $100 per person. If you charge for a municipal service other than water, sewer, garbage, and stormwater through your general utility billing, you should check with your attorney as to whether such fees are valid. The attorney that prevailed in this matter has at least two other cases pending, of which I am aware. Source: http://articles.orlandosentinel.com/201404-27/news/os-lk-fruitland-park-fees-lawsuit20140427_1_judge-oks-settlement-fire-fees-jim-ri chardson ; and http://www.wuft.org/news/2014/ 03/12/ocala-faces-lawsuit-over-unauthorizeduser-fees/.

Gerald Buhr is a utilities attorney who holds a Class A license in back water and wastewater treatment. A Florida Bar-certified specialist in city, county, and local government law, he is the city attorney for Mulberry, Zolfo Springs, Bowling Green, and Avon Park and reprresent Lake Wales on water and wastewater legal issues.

January 2015 • Florida Water Resources Journal

F W R J

You Don’t Know What You’re Missing: Designing a Grit Removal System That Works Marcia Sherony and Pat Herrick eeting regulatory requirements for treated effluent and solids quality has been the major focus for wastewater treatment facilities. Grit is often treated as an afterthought, and yet, wastewater treatment plants are significantly impacted by grit. A nuisance material, grit causes abrasive wear and tear to mechanical equipment, increases maintenance and operational costs, and accumulates in processes throughout the plant, which all reduce processing capacity and efficiency over time. It’s common to find operator dissatisfaction with grit removal systems; the design of grit removal processes has been labeled as inadequate, neglecting, and misunderstood. Conventional design guidelines target removal of grit larger than 210 micrometres (µm), while minimizing organic content. In fact, many wastewater treatment plants across the United States find that over 50 percent of their influent grit is smaller than 210 µm. In addition to designing for inadequate removal based on size alone, other factors contribute to grit system failure. Conventional engineering practices assume that municipal grit behaves like clean sand particles in clean water. Grit removal systems are traditionally based on settling velocities of perfect spheres of clean silica sand particles with a 2.65 specific gravity (SG) in clean water. In reality, wastewater grit is comprised of silica sand, as well as

asphalt, limestone, concrete, and various other materials that do not have an SG of 2.65. Grit particles are not all perfect spheres, and further, wastewater grit is exposed to fats, oils, greases, and soaps in the collection system, which coat the grit and alter its settling velocity. The cumulative result is inadequately performing grit removal systems that allow grit to be carried over to downstream processes and equipment. Grit systems can work as intended when designed with an accurate understanding of the nature and characteristics of the grit arriving at the treatment plant and how this grit actually behaves in wastewater. An effective system addresses size as well as settleability, produces a clean dry product for landfill, and minimizes deposits and accumulations in the plant. This article discusses why conventional grit system design criteria are ineffective and provides guidelines for determining design requirements. Also discussed are types of grit collection, washing, and the dewatering equipment and processes that are available and their effectiveness. The reduction in processing capacity can affect a plant’s ability to achieve process design goals, such as reduced methane production or increased alkalinity in digesters, and increase operational costs, such as horsepower requirements in aeration basins. Accumulations happen gradually and continuously, and they often go unno-

Figure 1. Grit deposition in fine bubble aeration basin.

January 2015 • Florida Water Resources Journal

Marcia Sherony is national sales manager and Pat Herrick is regional sales manager with Hydro International, Water and Wastewater Division, in Hillsboro, Ore.

ticed until a process is completely overwhelmed and needs to be shut down to manually remove the deposited grit, which is a labor-intensive and costly operation. When a process must be taken offline, the entire plant flow must be diverted. This requires building excess plant capacity to use as grit storage, which can significantly increase the size and cost of the plant The main focus in the design of a wastewater treatment plant is meeting regulatory requirements for treated effluent and solids quality. Traditionally, the design intent of grit removal systems, based on information from Metcalf & Eddy and the Water Environment Federation Manual of Practice No. 8, has been to target grit at 210 µm and larger (with an SG of 2.65). This design criterion has been more focused on producing a product with low organic content in order to make it acceptable at a landfill than it is on a specific target for removal efficiency of the grit itself. Producing a product with low organic content is a goal to keep in mind when designing a grit removal system. Organics create odor issues and increase volume and water content, which can make the product unacceptable at a landfill The wastewater industry has not taken much more than a cursory view of grit removal design criteria and the characteristics of the grit entering wastewater treatment plants. Unfortunately, the result of this approach has resulted in the capture of less than 50 percent of the grit entering a plant. As the industry moves toward higher-performing processes, effective grit removal will become a more important criterion in treatment plant design. The acceptance of membrane bioreactor (MBR) technology brings the need for advanced grit management systems into consideration for effective pretreatment processes. The MBR technology requires extensive screening pretreatment, which often allows elimination of primary clarification. Without the Continued on page 50

FWPCOA TRAINING CALENDAR SCHEDULE YOUR CLASS TODAY! JANUARY 12-15 12-16 23 26-30 26-30 26-30

....Backflow Tester ........................................St. Petersburg ....$375/405 ....Reclaimed Water Field Site Inspector ....Deltona ............$350/380 ....Backflow Tester Recert*** ........................Deltona ............$85/115 ....Water Distribution 3, 2 ............................Deltona ............$275/305 ....Wastewater Collection A..........................Orlando ............$225/255 ....Water Distribution 1 ................................Orlando ............$225/255

FEBRUARY 2-17 ....Wastewater Collection C, B** ..................Miami-Dade ......$225/255 9-12 ....Backflow Tester ........................................Deltona ............$375/405 27 ....Backflow Tester Recert*** ........................Deltona ............$85/115

MARCH 2-5 ....Backflow Tester ........................................St. Petersburg ....$375/405 9-13 ....Reclaimed Water Field Site Inspector ....Deltona ............$350/380 16-20 ....Spring State Short School ........................Ft. Pierce

April 13-15 13-16 13-17 13-17 13-17 24

....Backflow Repair ........................................St. Petersburg ....$275/305 ....Backflow Tester ........................................Pensacola ..........$375/405 ....Reclaimed Water Field Site Inspector ....Orlando ............$350/380 ....Water Distribution Level 3, 2 ..................Deltona ............$275/305 ....Reclaimed Water Distribution C..............Deltona ............$275/305 ....Backflow Tester Recert*** ........................Deltona ............$85/115

Course registration forms are available at http://www.fwpcoa.org/forms.asp. For additional information on these courses or other training programs offered by the FWPCOA, please contact the FW&PCOA Training Office at (321) 383-9690 or training@fwpcoa.org. * Backflow recertification is also available the last day of Backflow Tester or Backflow Repair Classes with the exception of Deltona ** Evening classes *** any retest given also

You are required to have your own calculator at state short schools and most other courses. Florida Water Resources Journal â&#x20AC;˘ January 2015

Continued from page 48 protection of primary clarification, advanced grit removal should also be part of an effective MBR pretreatment system design. Ideally, grit should not be entering a MBR plant where it can damage the membranes, which are the most expensive component of the plant. Even as upgrades are made from coarse bubble aeration to fine bubble aeration, the potential for grit deposition increases as the scouring velocities in the basins change (Figure 1). In conventional plants, where primary clarifiers are eliminated and aeration basins are converted to fine bubble aeration, the aeration basin directly follows the headworks. An ineffective grit removal process presents a new maintenance challenge as diffusers cover the full floor of the basin, which restricts the abil-

ity to clean the basin, making the cleaning process more operator intensive and expensive. Diffusers covered with grit are less effective and additional horsepower may be required to achieve desired results. A major reason that conventional grit removal systems do not work is a lack of understanding of how municipal grit actually behaves in wastewater. Since grit is not well understood, it is often erroneously treated as clean sand particles. This is a major reason why most grit removal systems fail to capture the quantity and sizes of grit for which they were designed. Understanding the actual characteristics of grit at a particular plant helps determine the size and type of grit removal system that is needed to remove it. Conventional design criteria have made

Figure 2. Compiled Particle Size Distribution from Treatment Plants

Table 1. Specific Gravity of Various Materials

January 2015 â&#x20AC;˘ Florida Water Resources Journal

the assumptions of dealing only with silica sand having an SG of 2.65. Each particle is assumed to be a perfect sphere settling in a quiescent basin of clean water. Ideal assumptions rarely work in municipal wastewater; in reality there are a variety of materials with a variety of SGs. The particles vary in shape and many plants have noted that much of their larger grit is flat. A flat particle will display much different settling characteristics than a sphere, and, while in the collection system, the grit particles are exposed to fats, oils, greases, soaps, and scum, which attach to the grit particles and alter the particles settling characteristics. Looking strictly at the size, and comparing the distribution, of grit from a variety of plants around the U.S., there are many plants where 50 percent of the incoming grit is smaller than the conventional design cut point of 210 Âľm (Figure2). Therefore, based solely on size distribution, half of the incoming grit is missing. If the design criteria are modified to remove 90 percent of the incoming grit, the design cut point needs to be changed to somewhere between 70-150 micron, depending on the endemic grit gradation. The conventional design criterion of 210 Âľm removal has allowed passage of a large amount of small grit into wastewater treatment plants; larger material is often found downstream of the grit removal process as well. The larger material that passes must be accounted for based on different criteria. One reason is that municipal grit is comprised of various materials and is not only silica sand. Table 1 shows the list of various materials that are likely to be constituents of grit that enters a wastewater treatment plant. None of the materials listed have an SG of 2.65. At the East Bay Municipal Utility District wastewater treatment plant in the Oakland, Calif., area, it was determined that the SG of its influent grit ranged from 1.95-1.6, with an average of 1.35. The settling velocity of a 1.35-SG particle is vastly different than a 2.65-SG particle. A 100-micron particle having an SG of 1.35 will take over four times longer to settle just 1 ft than the same size particle with an SG of 2.65. This is an important fact considering that grit collection devices predominately rely on gravity to make the separation. Additionally, attached fats, oils, greases, soaps, etc., coat the grit particles and change their settling velocity. As grit is more closely examined for its makeup and factors that affect settling velocity, it is easy to see that influent grit does not settle like clean sand in clean water. Determining grit-size distribution and settling velocity is not an easy task. First, there is no industry standard method for measuring

grit and obtaining a representative sample is difficult because grit does not flow evenly into the plant. It tends to travel in a higher concentration at the bottom of the channel; volume fluctuates with diurnal flow variations and grit volume significantly increases during wet weather events. Because of these variations, testing should occur over several days and ideally include a wet weather event, if possible. During peak wet weather events, grit volume entering the plant can be 20-40 times higher depending on peak-to-average flow ratio, age, and type of collection system. As much as 70 percent of the annual grit load can be received at the plant during a handful of first-flush events. These peak periods frequently overload poorly performing systems. Once sampling is complete, the size distribution must be determined, and in order to have the most accurate data upon which to base a design, the settling velocity or SG should be determined. Since conventional design guidelines continue to prove ineffective, a more comprehensive design guideline should be used. Several factors should be considered when designing a grit removal system, starting with a full-characterization endemic grit, including grit load, size distribution, and SG. With good data of the endemic grit, a cost-benefit analysis can be determined, evaluating grit removal efficiency as compared to cost. Other considerations include upstream screening requirements, maintenance requirements, space, and headloss.

Technology Review There are three basic types of grit collection systems: gravity sedimentation, aerated grit basins, and vortex grit basins. Gravity sedimentation systems, which include velocity control channels and detritus tanks, are the oldest types of systems. Maintaining a constant channel velocity or overflow rate at wide rages of flows can be a challenge. To maintain a balance, the system may be undersized at peak flows and oversized at low flows. These systems can be designed to effectively capture grit; however, when sized for a high-capture efficiency, organics will be captured along with the grit and an effective washing and dewatering system is needed. As organics in the captured grit became a nuisance, aerated grit systems became popular. The addition of air helped to reduce the amount of organics captured with the grit and provided preaeration to the incoming flow stream. Air, which is introduced into a basin via diffusers located near the bottom, creates a spiral roll pattern directing grit to the bottom for collection, while keeping organics in suspen-

Figure 3. Free Vortex and Forced Vortex Measures

sion. There is conflicting research as to what constitutes optimum aerated grit basin geometry and aeration rate. As a result, there are many improperly functioning systems. There are many improperly functioning aerated grit removal systems that lead to the popularity of vortex systems. In addition, in the U.S., many plants are large and significant cost savings can be realized using vortex basins in lieu of the constant cost of energy required to induce air into an aerated grit basin. Vortex basins are classified as either a forced vortex or free vortex. Both take advantage of centrifugal force to assist in grit removal, but the flow regimes are very different (Figure 3). In a forced vortex, the fluid rotates as a solid body with a constant angular velocity. Circumferential velocity is lowest at the center of the tank creating a quiescent zone at the center. The grit migrates to the center and is collected into a sump located at the bottom of the unit. In the open or free vortex, the centrifugal velocity increases as the flow migrates toward the center of the unit. In a free vortex vessel, the grit is thrown to the outside of the vessel, or held in suspension, then settles to the bottom where it is captured in the boundary layer and swept to the center of the unit for collection. The forced vortex flow regime is characterized by low headloss, with wall velocities being highest and decreasing performance as flows increase. In contrast, open or forced vortex flow regimes are characterized by high headloss, with wall velocities being lowest and increasing performance as flows increase. Several types of vortex technologies are available; mechanically-induced vortex, structured flow vortex, and stacked tray vortex are all examples of forced vortex technologies. Forced vortex systems are predominantly gravity-based systems, as gravity tends to be the

dominating force. Because of the head requirement and size restrictions, the free vortex products have limited application in grit collection. Free vortex devices are more commonly applied in mountainous areas where natural head is available or when the flow is pumped to an elevated headworks. These open vortex units offer the benefit of collecting and washing the grit in a single step. Due to the headloss requirement, the open vortex design is more commonly used for grit washing. The mechanically-induced vortex unit is popular. Characterized by low headloss, typically < 15cm (6 in.), removal efficiency is generally based on larger particles, 95 percent removal of 300 micron, and lesser removal of smaller size fractions. It is not uncommon for the design engineer to add a safety factor of 1.52 to the basin sizing recommended by manufacturers. The manufacturer sizing does not seem to be consistent across unit sizes with varying overflow rates and detention times. Plants have reported varying success with this technology. A laminar flow pattern into the basin is needed with approach channels typically four to seven times the channel width; flow discharges from the perimeter of the unit and a specific downstream channel configuration or effluent weir are required. In the center of the chamber a rotating paddle maintains circulation within the chamber, lifting organics out of the grit sump. Grit is collected in a center sump and pumped from the unit intermittently. The structured flow unit has proven to be effective at removing grit as small as 106 micron. Headloss through this type of unit is slightly higher, in the range of 15-30cm (6-12 in.). Internal components structure the flow regime, taking full advantage of the area within the vesContinued on page 52

Florida Water Resources Journal â&#x20AC;˘ January 2015

Table 2. Technology Summary

Continued from page 51 sel and eliminating short circuiting. A downward spiral is created at the outside of the unit, encouraging grit toward the bottom of the unit. Near the bottom of the unit, flow direction changes, creating a shear zone that has near-zero velocity, allowing grit to fall out and be captured in the bottom of the unit beneath an inverted cone. Flow must exit the unit near its center and within the dip plate. The dip plate helps to structure the flow and increase residence time of the grit, providing time for it to settle. All flow passes through the zero velocity zone prior to discharge ensuring effective removal. Grit is collected in a sump at the bottom of the unit, fluidizing water is added intermittently to remove organics, and the grit slurry is then intermittently pumped to a dewatering unit. The stacked tray vortex unit utilizes the simple principles of surface area, settling velocity, and overflow rates. Flow is evenly distributed via a distribution header to stacked, multiple, conically-shaped trays. Trays are available in several diameters and can be supplied in stacks up to 12 trays tall. Tangential feed to the stacked trays provides the vortex flow pattern. Solids have a very short distance to settle before they are captured in the boundary layer, swept to the center of the tray, and fall through a common opening to a grit sump located at the bottom of the unit. Design headloss is 30 cm (12 in.) at peak flow and headloss is less at lower flows. Particle settling velocity and overflow rates or surface area loading rates are used for sizing with proven capture efficiency as small as 75 micron. The grit slurry captured in the grit sump is typically pumped continuously to washing and dewatering. A summary of the technologies is listed in Table 2. When designing a grit removal system, the

washing and dewatering component must be as effective as the collection device, otherwise the overall system efficiency will suffer. A system approach is best. A study done in Fox Lake, Ill., showed that while the aerated grit basin removed 58 percent of total grit volume entering the plant, the cyclone/screw conveyor washing and dewatering equipment only retained 17 percent of what it received. The loss of grit in the washing and dewatering step reduces the systemâ&#x20AC;&#x2122;s overall efficiency to only 10 percent. Cyclones partnered with screw classifiers have traditionally been the technology of choice for washing and dewatering, without much evaluation of their effectiveness. Both technologies are borrowed from the mining industry. When applied in mining, a slurry is delivered to the equipment with a specific cut point particle in mind. The slurry is relatively consistent in flow and concentration. Flows of collected grit are not consistent in concentration. The material to be separated included fine and coarse grit, as well as fine and coarse organics. The goal is to retain all grit, both large and small, while discharging most organics. In these systems, the larger organics tend to be captured with the grit and grit fines are lost back to the system. The cyclone operates with a free vortex flow regime; headloss is high, and therefore, the flow is typically pumped to the unit. Grit is forced to the outside of the unit and concentrated as is sours down the tapered sides through the apex valve at the bottom of the unit. The apex valve is a fixed orifice and restricts the volume that can be discharged. Wet weather events, when the grit load can be 20 to 40 times the normal volume, present problems for cyclones. The increased volume of grit cannot physically pass through the apex valve. Since what goes in must come out, the

January 2015 â&#x20AC;˘ Florida Water Resources Journal

grit that cannot physically pass through the apex valve discharges out of the top of the unit and ends up in downstream processes or the valve plugs. Other free vortex units available possess a larger diameter body, providing a larger capacity for grit during these wet weather events. The larger diameter free vortex units utilize a panshaped bottom. A boundary layer develops at the bottom of the unit sweeping the settled grit toward a center collection and discharge point. The boundary layer is effective for retaining even the fine grit particles, but because it is thin, the larger organics that will tend to settle with the grit are too large to remain in the boundary and are swept back into the rotating vortex above and ultimately discharged. Screw classifiers have conventionally been sized on the capacity of the rotating screw. The overflow rate of the clarifier section is often overlooked. When the classifier is fed with a high-surface loading rate, most organics overflow out of the system along with the fine and lighter grit, yet some of the larger organic particles are retained with the captured grit. Volatile solids discharged from these systems typically range from 25-35 percent, with some plants seeing volatile solids concentrations as high as 70 percent. In addition, screw speed is often overlooked. For example, a screw with a 30-cm (12 in.) diameter rotating at only four revolutions per minute (rpm) has a tip speed roughly equivalent to the settling velocity of a 400-micron particle. As the screw rotates, it suspends the finer material, both organics and grit alike. As additional flow is fed to the clarifier, the smaller particles that are in suspension are lost over the weir and end up in downstream processes. Clarifier overflow rates should be considered in the design of the classifier, especially following effective washing. The screw must run slowly so as not to resuspend the captured material. In lieu of a rotating screw, a slow-moving belt can be utilized so as not to resuspend the grit, but gently raise settled grit out of the clarifier to a discharge point at the top of the unit, which deposits the dewatered grit into a dumpster. Test results on the large-diameter free vortex unit, coupled with the dewatering device with a large clarifier area and slow moving belt, are excellent, generally delivering a product with fewer than 20 percent volatile solids and >60 percent total solids.

Conclusions It is not uncommon to find operator dissatisfaction with grit removal systems. Many installed grit systems fail to keep depositable grit

out of the plant; in fact, they fail to remove the sizes and amounts of grit they were designed to capture. Grit system failure happens primarily due to a faulty assumption that municipal grit behaves like clean sand particles in clean water. The failure of many traditional grit removal systems has led to the misconception that grit removal systems cannot work, and that the only option is to deal with the grit deposits downstream of the headworks and the abrasive wear from grit by increasing maintenance and operational budgets. In order to design an effective system, design guidelines should be more comprehensive than referring to an industry standard that has been labeled as inadequate, neglecting, and misunderstood. A clear understanding of the grit entering the plant that includes grit load, size distribution, and settling velocity is needed. Only with a clear understanding of the material to be removed can a system be designed to achieve specified results. Table 3. Design Guidelines Define Design Requirements:

• Grit Particle Size Analysis • Settling Velocity or SG • Required System Removal Efficiency • Screening Requirements Evaluate Equipment • Removal Efficiency/Performance • Equipment Design/Features • Space • Headloss • Cost: Capital, Installed, Operational • Maintenance Requirements

A grit removal system is just that, a system. All components of the system must be effective in order for the overall system efficiency to yield the desired results. Improving grit collection only to lose a major portion of it back to the process in the washing and dewatering step is detrimental to overall results. Capturing a high percentage of the incoming grit load, along with a high concentration of organics, yields a product difficult to landfill and can starve the biological processes. Each step of the grit removal process is important. Grit systems can work as intended when designed with an accurate understanding of the nature and characteristics of the grit arriving at the treatment plant and how this grit actually behaves in wastewater. An effective system addresses size as well as settling velocity or SG, produces a clean dry product for landfill, and minimizes deposits and accumulations in the plant.

References • Andoh, R.Y.G. and Neumayer, A. (2009). Fine Grit Removal Helps Optimize Membrane Plants. WaterWorld. January 2009, pp 28. • Boyrs, A., Gabb, D., and Hake, J. (2002). Performance Evaluation of Aerated Grit Chambers and Proposed Modifications to Increase Grit Removal Efficiency at East Bay Municipal Utility District WWTP. Conference Proceedings from California Water Environment Association Annual Conference, April 4. Session 22. • Griffiths, J. (2004). Fox Lake Regional WRF Grit Testing Results. Grit Solutions. May 7, 2004 and Aug. 19, 2003. • Boldt, J. (2005). Eliminating Grit Deposition Problems through Objective Grit System Design: A Case Study at the Fox lake NRWRP – Fox Lake, Ill. Illinois WEA Conference, January 2005. • Herrick, P. (2009). A Portable Solution for Degritting Aeration Basins. Pollution Equip-

ment News, January 2009, pp 17-18. • Keller, J. (2009). Buffalo Sewer Authority Aeration Basin Cleaning. Western New York WEA, February 2009. • Osei, K. and Andoh, R.Y.G, (2008). Optimal Grit Removal and Control in Collection Systems and at Treatment Plants, World Environmental and Water Resources Congress, Honolulu, Hi., 12-16 May. • Wilson, G., Tchobanoglous, G., and Griffiths, J. (2007). The Grit Book. Eutek Systems Inc., Hillsboro, Ore. • Reade Advanced Materials. Weight per Cubic Foot and Specific Gravities. Reade Specialty Chemical Resource Company. http://www.reade.com/Particle_Briefings/ spec_gra2.html (Accessed February 2010). • Water Environment Federation and ASCE (2009) WEF Manual of Practice No. 8, 5th Edition, Alexandria, Va., WEF, ASCE. • Wilson, G.E. (1998). Why do Conventional Grit Systems Have Performance Problems? PNPCA Annual Conference, Portland, Ore.

News Beat The Resources and Ecosystems Sustainability, Tourist Opportunities, and Revived Economies of the Gulf Coast Act of 2012 (RESTORE Act) allocates 80 percent of the Clean Water Act administrative and civil penalties resulting from the Deepwater Horizon incident to the Gulf Coast Restoration Trust Fund. To date, Transocean is the only responsible party to settle its civil liability, and a portion of those funds are now available. The councilselected restoration component, commonly known as Bucket 2, equates to 30 percent of available funds and is managed by the council. For this first round, the total funding available for projects is roughly $150 to $180 million to be shared among 11 council members. Once the council staff receives all member proposals they will be reviewed for eligibility and posted online. The council members will then work to create a draft funded priorities list, which will be available in the spring/summer of 2015 for public review and comment. Florida will compete for Bucket 2 funding with the other states and federal agencies represented on the council. The proposals must align with the council’s comprehensive plan, which was published in August 2013. The Department of Environmental Protection and Florida Fish and Wildlife Conservation Commission have been working diligently to ensure Florida’s Bucket 2 proposals align with the council’s goals, have

wide support, and significantly contribute to the overall health of the Gulf of Mexico. The RESTORE Act funding is just a small portion of the overall environmental restoration work that is being implemented in Florida to compensate the public for injuries caused by the Deepwater Horizon spill. To date, there has been nearly $175 million in approved projects and programs across Florida’s Gulf Coast communities through other funding sources, such as Natural Resource Damage Assessment early restoration and National Fish and Wildlife Foundation’s Gulf Environmental Benefit Fund. These projects range from living shorelines, land acquisitions, boat ramps, coastal conservancy, and enhanced recreational use. Project selection processes among these multiple funding sources are coordinated to ensure projects that are chosen are complementary and successful for the Gulf Coast. These projects come on the heels of Florida securing a record level of funding for important environmental projects through the state budget. This year, more than $300 million was approved for projects to improve water quality in south Florida and the Florida Keys. This investment will be used for critical projects for families and businesses that rely on these areas, mitigate the impacts of Lake Okeechobee’s discharges on estuaries, and divert more fresh water south to help restore the Everglades.

Florida Water Resources Journal • January 2015

PROCESS PAGE Greetings from the FWEA Wastewater Process Committee! We are excited to bring you this edition of “The Process Page,” with information on one of the many outstanding educational events we sponsor.

Southeast Process Seminar a Success! Kristiana Dragash rom feeding $2 million of illegally imported honey into the digesters at Reedy Creek Improvement District to implementing a $1.6 billion sewer system consent decree in Miami Dade, the line-up of topics—and distinguished speakers—at the Southeast Process seminar, presented on November 6th last year, covered it all! Over 70 professionals, including plant operations staff to utility directors and consultants from around the state, listened intently in the City of Boca Raton’s spacious auditorium for a full day of wastewater process presentations. The topics and presenters included: Operational Approaches to Improve Nitrogen Removal and Save Energy - Sean Scuras, Ph.D., P.E., Tetra Tech

Sidestream Management Alternatives: Finding a Practical and Economical Approach Rod Reardon, P.E., Carollo Engineers Implementation of Miami-Dade County’s Consent Decree for Sewer System Improvement - Manuel Moncholi, Miami-Dade Water and Sewer District Thermal Hydrolysis Systems Around The World to Increase Sludge Volatile Solutions Reduction - Paul Christy, CAMBI Energy and Nutrient Extraction from Organic Wastes to Achieve Net-Zero Treatment Objectives - Ted McKim, P.E., Reedy Creek Energy Services Sustainable Aeration and Other Methods for Saving Energy and Capital Costs in Broward County - Chuck Flynn, City of Plantation Getting More Out of Activated Sludge Plants by Using a Biomag Process - Eli Tilen, P.E.,

January 2015 • Florida Water Resources Journal

Brown and Caldwell Redefining Being Green: Advanced Biological Nutrient Recovery with Algae - Jane Madden, P.E., CDM Smith Direct Aquifer Recharge: Advanced Oxidation Process Treatment for Microconstituent Removal Without Reverse Osmosis - Enrique Vadiveloo, P.E., Hazen and Sawyer The Current State of the Art in Membrane Bioreactor Design - Carsten Owerdieck, GE Water As with all of our seminars, the committee worked very hard to put together this top-notch program. We would like to express our sincerest thanks to the following individuals for their hard work and contributions in the planning of this successful seminar: City of Boca Raton and Lisa-Wilson Davis for supplying the wonderful facility.

Our generous sponsors who helped to make this event possible. All of the speakers, who donated their time and energy to their presentations. Maricela Fuentes with AECOM for sponsorship coordination. Wisler Pierre-Louis with City of North Miami Beach and Ron Shupler with Heyward Florida for coordinating lunch and refreshments. Eric Stanley and Rosalyn Matthews with Hazen and Sawyer, for technical program coordination and chairing the event. Suzanne Mechler with CDM Smith, and Monique Durand and Cristina Garcia-Marquez, for working on the registration committee. Kenny Blanton with Black and Veatch for coordinating the professional development hours and continuing education units. Matt Love with McKim and Creed and Karen Wallace with FWEA for taking care of the website. Jody Barksdale with Gresham, Smith, and Partners for chairing the statewide FWEA Wastewater Process Committee. I was honored to chair the publications subcommittee.

Ted McKim, P.E., with Reedy Creek Energy Services, explains anaerobic digestion in a simplistic yet amusing manner during his presentation, “Energy and Nutrient Extraction from Organic Wastes to Achieve Net Zero Treatment Objectives.”

We will have many events in 2015, with a full-day workshop at the Florida Water Resources Conference in May, and more seminars in other locations, with Jeff Lowe of McKim and Creed at the helm of the Wastewater Process

Committee ship! We hope to see you at one of our events! Kristiana Dragash, P.E., is with Carollo Engineers in Sarasota and is an FWEA director at large.

Florida Water Resources Journal • January 2015

C FACTOR

Thanks for a Great Two Years! Jeff Poteet President, FWPCOA

his is my last article as your president. It’s hard for me to believe that two years have passed since I took over the helm of this great association. As I reflect back on my tenure here, I am amazed by the dedication of our membership. It is our members that have made my two terms as president a truly amazing and enjoyable experience. As president, there are a few of our members that I would like to highlight for their efforts and contributions. I cannot possibly mention all of those people who have contributed to the success of FWPCOA; however, there are people like: Art Saey, who heads up the association’s largest committee, the Education Committee. Art has done an excellent job organizing this group and it is the efforts of the entire committee that make our programs stand out from the crowd. Jim Smith is the chair of our Short School Committee. This past short school was one of the most successful schools the association has had and we could not have done it without his efforts. Rene Moticker is our Awards Committee chair. She has done an outstanding job in getting the word out about our awards program. The number of nominations submitted for awards has dramatically improved since her involvement, making those recognized stand out even more. In today’s high-tech environment you need a savvy computer geek, and we have that in Walt Smyser. Walt is our webmaster and he is instrumental in helping us get important information to our membership. Walt is another member that donates countless hours to improve our industry. Shirley Reaves, our training coordinator, helps our regional and state programs meet the Florida Department of Environmental Protection’s continuing education unit requirements and makes sure we all get the educational credits we achieve. Although Shirley is financially compensated

for her efforts, she goes far beyond what we pay her for. It would be remiss of me not to mention our Historical Committee Chair, Al Monteleone. Al helps us all recount the history of the association and stands up for what he believes in. And of course, there are the endless efforts of Rim Bishop, secretary/treasurer; our former executive director, Tim McVeigh; and past-president, Ray Bordner. Rim, Tim, and Ray have helped me and this association in countless ways. They have guided my efforts in promoting the association and helping us continue to provide the best training in our industry, while helping to keep the cost of those programs down. I truly appreciate all of the people I have mentioned and their ongoing efforts for the organization, along with so many more members that I haven’t mentioned. Thank you all for your confidence and support. I look forward to working with you for many years to come!

Silent Sentinels As I have professed on many occasions, I truly believe that our water professionals are the “silent sentinels” of our communities. When we do our jobs properly, regardless of the daily situations that test our drinking water and wastewater systems, the consumer does not realize the struggles that we, as water and wastewater professionals, go through; our efforts typically—and unfortunately—go unnoticed. We don’t get the accolades or recognition of our fine police and fire departments do, even though we, too, are first responders—without us doing our jobs, it would be impossible for them to do theirs. When we do our jobs correctly, we are not in the minds of the public, and that’s okay, it’s what we do, as silent sentinels. We all should be proud of the roles we play in the communities that we serve. On behalf of FWPCOA, I recognize and thank you for your efforts.

License Renewal and Continuing Education Please remember that 2015 is a license renewal period and FWPCOA can help you meet your educational requirement for li-

January 2015 • Florida Water Resources Journal

cense renewal. In 2015, we will continue to have some outstanding training opportunities for our members. Many of these opportunities will expand your knowledge and, at the same time, allow you to acquire those needed continuing educations credits. The FWPCOA Spring Short School is all set for March 16-20. The school will once again be hosted at the Indian River State College and applications are available online at www.fwpcoa.org. For many of our members, however, a short school may not be the answer. If you’re looking to get your educational requirements from the convenience of your home, then our online training program is what you’re looking for. Our online experience has expanded and has an array of topics to choose from. Please see our website for more information on the association and additional regional information.

Your Association Needs You! If I have one last message to give out it is a plea for you to get involved in the industry that you are a part of. I have mentioned this before and I’ll continue to opine about the importance of being involved in the industry in which you work. Many people get involved because they want to give back to something that has given them so much. I got involved for selfish reasons: I saw it as a way to help my career. I had little leadership experience and I needed something to put on my resume. I started going to meetings with little participation; kind of like a lampshade sitting in the corner. Then I progressed to helping at a regional short school, then teaching, and then setting up an entire school. My career has directly benefitted through my involvement with the association. Before I knew it, my job went from an operator trainee to the director of the utility. But that is only the tip of the iceberg! It is from the lifelong friendships and memories that I have truly gained most. To know people like Grady Sorah, Bill Allman, Ray Bordner, Tim McVeigh, and Rim Bishop (just to name a few) has truly changed my life for the better. There are a few other people that I need to thank for helping me take the lampshade off my head and getting me involved in this Continued on page 57

FSAWWA SPEAKING OUT

Reasons to be Thankful in the New Year Mark Lehigh Chair, FSAWWA

s I sit here days before the Thanksgiving holiday writing my article for this issue, my mind is flooded with all the things that I am thankful for. First and foremost are my family and my health. I am extremely thankful for my family and the support they have given me to pursue my career and passions. I have also enjoyed good health in my life and do not take it for granted. The last two past chairs of the section have been the key to my success and continue to help me out every time I ask. I want to thank Carl Larrabee for his service to the section this past year. His wisdom and guidance have helped me on both a personal and professional level. The mentoring program he rolled out has been a big success and he has all my support with this program moving forward. I also offer my thanks to Jason Parrillo for his guidance, knowledge, and passion for the section, all of which are second to none. He helps me on a daily basis and is always glad to do so. His three-year membership vision utilizing the Strategic Membership Task Force has moved the section in the right direction. I plan to finalize his vision and bring it to fruition this year. I would be remiss if I did not mention a

C Factor Continued from page 56 life-changing organization. To Dave Denny, Jake Rohrich, Mike Switzer, and Jon Meyer, I say thank you! My life is truly enriched because you asked me to get involved in the organization. Whether you have noble intentions, or your motivation is self-centered (like mine

few of the other past chairs who have taken me under their wing and or given me advice along the way: Jeff Nash, is the consummate professional, a great speaker, and a close friend. Jackie Torbert, the “Million Dollar Chair,” has freely shared her utility viewpoint. Matt Alvarez, with his blue blazer, is who I want beside me when things get tough. He shines in those situations. Rick Ratcliff, my Region IV compadre and conference organizer extraordinaire, slices straight to the core of any issue with common sense and laser focus. He gets things done, period. Richard Anderson, who was my first mentor as Region IV chair, paved the way for me. I have learned much from all of these great leaders. The time to act is now—no more “wax on and wax off ” for me. Hillsborough County Public Utilities Department has been my place of employment for 32 years. The department name has changed at least three times over my career, but the vision, mission, and goals have remained steady. It’s a great time to be a county employee. I thoroughly enjoy the people I work with; the authentic connection with management and the camaraderie amongst the employees are at an all-time high. I am trusted and treated with respect, and have been given the opportunity to grow while participating as a member of FSAWWA. Great workplaces are built through the dayto-day relationships that employees experi-

was), go out to your local FWPCOA meeting and sit in the corner. Just maybe, someone will come by and take the shade off your head and improve your life and your career.

Last Meeting My last meeting as your president will be in Winter Haven on January 16. At that meeting, the gavel will be returned to Tom King

ence, and my experience has been a very good one. The Florida Section of the American Water Works Association is my trade organization of choice and I think it’s a perfect fit for me. Many years ago, Glenn Yaney, a past chair of the section, longtime friend, and a chair of Region IV at the time, reached out and got me involved. Little did I know it would lead to serving as the chair of Region IV, and now serving as section chair. If you haven’t helped out or volunteered at the regional level, I highly recommend it. My experience was extremely rewarding. I made many contacts with manufacturers, learned about new products, and met some amazing people who are close friends to this day. I can’t begin to tell you how helpful the training, mentoring, and contacts have been to me daily in my job with the county. As a utility person, I have found membership with FSAWWA to be invaluable. Peggy Guingona and the FSAWWA staff have been nothing short of professional, friendly, helpful, and of course, amazing. Thanks to Peggy, Casey Cumiskey, Donna Metherall, and Jenny Arguello for a job well done. They are always there to answer any questions and help with last-minute requests. They have nearly erased the memory of what it was like before this all-star staff was assembled. If you ever need a question answered or require information about FSAWWA, please don’t hesitate to call any one of them at section headquarters—I guarantee you will be pleased. Thank you all for the opportunity to represent and serve FSAWWA

for a second term. Tom is another one of my heroes! He is dedicated to improving our organization and I look forward to supporting him in the year to come. I also look forward to reading his articles; he has a terrific sense of humor and a genuine ability to communicate ideas that will help the association move forward. See you in Winter Haven!

Florida Water Resources Journal • January 2015

F W R J

Continuous Rotating Belt Filtration for Primary Treatment and Combined Sewer Overflows Miguel Gutierrez n effective equivalent to screening and primary settling, rotating belt filters enable a design with minimal footprint, as well as implementation at a fraction of the life cycle cost of conventional technologies. Existing wastewater treatment plants needing an upgrade can implement these filters to expand primary clarification, relieve solids loading to the secondary system, or provide treatment for combined sewer overflows (CSO). The associated hair and grit removal provides a high level of protection for membrane plants. There are multiple drivers for rethinking conventional settling and clarification, including footprint, level of treatment, and the power demands for operations. Rotating belt filtration is becoming an accepted solution to several distinct challenges in clarifying wastewater in municipal and industrial applications and the prevalence of use has grown, particularly in Europe, over the past two decades. With hundreds of plants around the world utilizing this technology, it is worthwhile to take a closer look at the design considerations. Real estate can often make or break the feasibility of a wastewater system upgrade or expansion. Many plant expansions are halted, slowed, or come with astronomical costs due to lack of space. Upgrades, including the expansion of design flow to the facility of process redesign to incorporate biological nutrient removal (BNR), are examples of situa-

tions that would benefit from rotating belt filters (RBFs). The RBFs can being integrated to gain back space. They require 5 percent of the footprint of a conventional clarifier and offer higher levels of primary treatment, including grit removal. Existing primaries can be expanded or changed over completely with RBFs, and the real estate previously occupied can be reallocated for secondary treatment. This strategy is being considered and applied throughout the United States, the South Pacific, and Asia. Figure 1 illustrates the relative footprint savings of RBF technology when compared to conventional primary clarification of the same performance capacity; the rendition on the left illustrate a nominal 3-mil-gal-per-day (mgd) footprint, while the rendition on the right illustrates a nominal 100-mgd comparison. Designing RBFs as primary treatment in new plants will save capital expenditure in equipment and civil works. With a smaller footprint, there are potential savings in excavation, engineering, piping, and many other aspects of the capital project. The compact footprint and low life cycle cost make this technology a desirable method for treating sewer overflow. Another beneficial aspect of treatment with RBFs is that the technology provides a physical rather than hydraulic sequestration of particulate and hair, which can create havoc in the secondary system. A range of activated sludge and

Miguel Gutierrez is business development manager for Blue Water Technologies in Hayden, Idaho.

fixed film secondary systems benefit from the mitigation of hair, as do membrane systems. Multiple membrane manufacturers around the world are transitioning to RBFs for primary and pretreatment in membrane plants to extend membrane life. The RBFs are appealing from a life cycle cost standpoint as well. Implemented at a fraction of the construction cost of conventional primary tanks, is has a big up-front savings. Power usage savings, both in the primary treatment system as well as in downstream aeration, help provide a life cycle cost comparison that is one-fifth of the conventional costs associated with primary settling.

Method of Treatment The RBFs remove solids through the use of a continuous-loop fine mesh belt screen. A side-view sketch of a RBF unit is shown in Figures 2. The belted screens move linearly, directed by filter headloss input to a programmable logic controller. As the screen moves, it acts as a conveyor and carries captured solids out of the incoming wastewater. A

Figure 1. Scale Comparison of Rotating Belt Filters to Conventional Clarification With the Same Performance Capacity

January 2015 â&#x20AC;˘ Florida Water Resources Journal

capable cleaning system is a critical aspect of RBFs as the cleaning system is responsible for removing collected solids and providing a clean surface for treating incoming water. Solids from the belt screen are discharged and deposited into a screenings hopper. The solids drop into a hopper and the screen is cleaned as it moves past the rollers. High-pressure water spray is use to dislodge the remaining solids off the belt. For applications with oil and greases, periodic hot water high-pressure washes are implemented to redissolve the oil and grease and to consequently regain the porosity of the belt. This method has proven highly effective over air backwash techniques, which tend to cook the oil and greases right into the pores of the belt. A screw press dewaters the collected screenings that have be-

tween 20-40 percent dry solids, while screened wastewater continuously passes through the unit. Dewatering screens pass a paint filter test, which is approved by the U.S. Environmental Protection Agency (EPA, 9095B) and helps determine if the dewatered solids have any free liquids after a predetermined sample is placed in a standard conical paint filter with a 60-

Figure 2. Rotating Belt Filters, Side-View Sketch

Figure 4. Total Suspended Solids Performance Data

mesh rating. If any portion passes through the filter in a five-minute period, the sample is deemed to have free liquid, making it unsuitable for landfill application. The RBFs remove between 40-70 percent total suspended solids (TSS) and 20-40 percent biochemical oxygen demand (BOD) from Continued on page 60

Table 1. Performance Data: Plummer Wastewater Treatment Plant

Figure 3. 1.7 mgd Capable Unit Tested at Plummer Wastewater Treatment Plant

Figure 5. Biochemical Oxygen Demand Performance Data Florida Water Resources Journal â&#x20AC;˘ January 2015

Continued from page 59 wastewater and the unique design allows for removal of organic and inorganic solids as fine as 15-30 micron. Removal efficiencies are affected in part by the ability to vary the belt speed. A slower belt speed results in higher capture rate of solids, creating a mat that not only results in a lower TSS effluent, but also shifts the particle size distribution for removal of smaller particulates. At higher belt speeds, the opposite effect seems to correlate; furthermore, the ability to control the belts’ speed and porosity allows a relative customization of a particular BOD performance to increase the efficiency of downstream biological digestion processes. The RBF units are compact, completely enclosed, low-maintenance solutions for wastewater. The integral odor containment of the design allows for indoor installation in a clean environment, and some models are even designed for food-grade compatible maintenance regulated by the Food and Drug Administration (FDA). Three manufacturers in the industry offer standard equipment, ranging in sizes suitable for small communities to large cities. There is no limitation in flow capacity designs.

Multiple engineering firms around the world have had an opportunity to study the umbrella of primary treatment technologies, and their reports deserve a studious look. To date, this technology has been installed on every continent around the globe. Case history, design considerations, and lessons learned from implementation of this treatment technology will highlight some of the residual benefits and operation and maintenance (O&M) savings to a municipality.

Primary Treatment Expansion with Capital Affordability: City of Plummer (Idaho) Wastewater Treatment Plant The City of Plummer, Idaho, is a small community of approximately 1,000 residents. Having commissioned a wastewater treatment plant in 2010 for advanced nutrient treatment to discharge less than 0.05 mg/L, it has struggled with the headworks configuration of its facility, primarily with grease and solids plugging the installed screens. The City’s most effective option to reduce O&M costs was to test a self-cleaning RBF unit that can effectively handle variable influent quality and levels. Fig-

ure 3 shows the RBF unit tested at the facility. The performance modeling completed during the summer of 2012 shows consistent removal of TSS between 33 and 87 percent and particulate BOD between 37 and 46 percent. The flow tested averaged 363 gal per minute (gpm), ranging from 283 to 434 gpm. Table 1 summarizes the overall results and Figure 4 and 5 depict the data graphical representations for TSS and BOD performance. This system will mitigate past O&M expense associated with the old headworks and screening configuration. Performance charts illustrate a dampening effect on influent condition extremes. The level of TSS and BOD delivered to the biological portion of the plant is more consistent following the RBF, leading to a more stable biomass in the secondary system.

City of McHenry, Ill. The wastewater division maintains and operates the City of McHenry's two wastewater treatment plants and 19 wastewater lift stations. Its goal is to efficiently maintain these facilities and to produce plant effluents meeting both state and federal standards. The division regularly performs testing to operate the plant and to report to the state EPA. The performance modeling completed during the spring of 2013 shows consistent removal of TSS between 24 and 63 percent and particulate BOD between 22 and 49 percent. The flow test averaged 169 gpm, ranging from 125 to 225 gpm. Table 2 summarizes the overall results. The level of TSS and BOD delivered to the biological portion of the plant is more consistent following the RBF technology, leading to a more stable biomass in the secondary system. Figure 7 and 8 depict the TSS and BOD achieved with the RBF unit

Primary Treatment of Inflow and Infiltration and Combined Sewer Overflow Conditions: City of Glendale, Ore.

Figure 6. 0.5 mgd Capable Unit Tested at City of McHenry Wastewater Treatment Plant Table 2. Performance Data: City of McHenry Wastewater Treatment Plant

January 2015 • Florida Water Resources Journal

During heavy rains and snow melts, the City of Glendale inflow and infiltration (I&I) inflow results in the bypassing and discharging of raw sewage to nearby Cow Creek. To demonstrate the effectiveness of RBF technology as the appropriate solution, the treatment objectives of operations were to remove a minimum of 50 percent TSS and 30 percent BOD. Treatment objectives were safely met during the pilot demonstration. As a less expensive alternative to a complete plant upgrade, the RBF unit cost ranges from $0.05-$0.10 per gal/day treated. Installation requires little civil work

Figure 7. Total Suspended Solids Performance Data

Figure 8. Biochemcial Oxygen Demand Performance Data

and construction, and the unit requires roughly the footprint of an automobile to treat the peak flows that Glendale experiences.

Total Suspended Solids and Biochemical Oxygen Demand Compliance

Demonstration Site Description The design capacity of the Glendale wastewater treatment facility is 0.451 mgd, or 313 gpm. Subunits of the plant process are as follows in order of water flow: Wet well immediately upstream of headworks. This gives operators the ability to bypass the plant during washout level flows and direct water to the outfall (Cow Creek). Raw sewage pumping station through headworks. Activated sludge treatment consisting in aeration, reaeration, and clarification. Tertiary sand filtration. Disinfection with liquid hypochlorite. Waste activated sludge (WAS) is routed to the aerobic digester and thickened utilizing a waste reduction unit.

The equipment ran smoothly without upsets, and maintained good performance throughout. Challenges with I&I and CSO peak wet weather flows included treating a diluted influent and dealing with the added volume that is typically much higher than plant capacity. Typical raw wastewater to municipal plants ranges from 200-450 mg/L in TSS. During periods of I&I, the TSS is significantly di-

The filtered effluent is discharged yearround to Cow Creek through a single outfall. The Glendale wastewater treatment facility receives an average of 100,000 gal per day (gpd), or 69 gpm, and 1 mil gal per day (mgd), or 690 gpm, under typical peaking conditions. According to the Glendale treatment plant staff, the plant produces approximately 117,000 gal of sludge per year, and the sludge is land-applied from June through October. By implementing RBF technology, Glendale would be able to bypass the existing plant during periods of peak flow without discharging raw sewage to Cow Creek. As the testing demonstrated, a very high level of solids and BOD removal can be accomplished. Combined with disinfection, the RBF technology can help facilities like Glendale minimize the environmental impact observed during peaking flow conditions.

luted to 50-150 mg/L. Diluted water streams are typically harder to treat with desired efficiency. The data set from this demonstration suggest that the RBF technology can maintain the minimum treatment efficiency of 50 percent TSS removal, easily meeting the challenges posed by peaking flows due to I&I. For this demonstration, influent TSS analysis contained no outliers and averaged 222 mg/L. Figure 9 illustrates the influent TSS consistency as separated from the filtration belt. Variable operations beyond plant control Continued on page 62

Figure 9. Influent Total Suspended Solids off the Belt by Nonmechanical Cleaning System

Table 3. Performance Data: Glendale Wastewater Treatment Plant

Florida Water Resources Journal â&#x20AC;˘ January 2015

Continued from page 61 occurred during the demonstration, resulting in influent levels a little higher than desired for influent infiltration or CSO applications and were handled effectively by the RBF unit. The unit

treated a flow of 95 gpm on average and the flow ranged from 65 gpm to 155 gpm. Effluent TSS averaged 51 mg/L, which corresponds to a 68 percent removal of TSS. Removal of BOD was likewise very efficient; influent averaged 212

Figure 10. Percent Removal for Total Suspended Solids/Biochemical Oxygen Demand and Flow Rate Range at Glendale Wastewater Treatment Plant

January 2015 â&#x20AC;˘ Florida Water Resources Journal

mg/L and the effluent averaged 75 mg/L. This corresponds to a reduction of 53 percent. Table 3 summarizes the performance achieved. Figure 10 depicts the percent removal of TSS and BOD as it corresponds to the flow range tested. Maximum BOD values were noted and were due to upstream dischargers such as restaurants or other industries. The level of treatment was nonetheless maintained during each day of operation. Composite of influent and effluent wastewater were also sampled for laboratory analysis. Results were very positive and showed slightly higher removal than that shown in grab samples. The TSS removal was 77 percent and BOD removal was measured at 67 percent. This demonstrates a reliable and sustainable process over an extended period of time during which influent conditions are constantly in flux. The equipment was operated at slightly lower hydraulic loading in order to get the highest removal possible for I&I and CSO applications. As a design parameter, the requirement of 50 percent TSS removal and 30 percent BOD removal could be comfortably achieved. This would allow the City of Glendale to treat wet weather flows to the levels outlined for discharge compliance.

New Products The Mini-Cam Proteus crawler, from Jack Doheny Companies, is an entry-level modular system for pipeline inspection. A robust, lightweight, and powerful six-wheel-drive, steerable crawler, it offers CAN technology, allowing communication directly between each piece of attached equipment, and can relay control and status information such as activity, speed, pressure, inclination, and temperature. It is compatible with ProPipe and WinCam V8 reporting

software, saving time and money and increasing productivity, Various system configurations can be adopted to suit individual requirements. (www.dohenycompanies.com)

STRAIGHT-Fit valves from Mainline Backflow Products come in 3-, 4-, and 6-in. sizes and are available in both PVC and ABS. They have a body that is extendable to whatever

depth is required and the gate can be extended for easy extraction as well. The valves have a Smart CURVE gate designed to allow a sewer snake to feed and retract without catching on the gate itself. A clear insert in the body eases the feeding and retrieval of a snake without hanging up, reducing excessive wear on the body. An optional test gate can be used to pressure-test the system or isolate the property. (www.backwatervalve.com)

Perma-Liner Industries distributes the Vac-A-Tee, which allows access to a lateral pipe for cleaning inspection and lateral lining through a clean-out. It can also be used to establish a new service connection at the mainline pipe. It is compatible with all types of pipe, incuding clay, cast iron, concrete, PVC, and HDPE, and is available in diameters from 4 to 24 in. The unit is homeowner friendly, with minimal disruption and restoration; utility friendly, eliminating the hazard of digging up water and gas lines; environmentally friendly, saving trees and landscaping; and installer friendly, requiring no large equipment or shoring. (www.perma-liner.com)

The Powervac Suck N Dump, from Presvac Systems, is a positive displacement blower wet/dry vacuum loader that operates as an air mover for dry applications. It offers full vacuum and extreme recovery rates for tough liquid, sludge, and slurry jobs. The material knock-out feature in the debris tank minimizes carryover and the heavy-duty modular filtration configured to blower CFM provides protection and minimum maintenance. It has 12-in. dump chutes and spring-tensioned bolts that allow for adjustments to maintain leak-proof sealing. The dump chute doors open with the debris tank door. Blower options include Hibon, Roots, or Robuschi, with a full vacuum offering 3,500 to 6,600 cfm. (www.presvac.com)

Summit software from Ritam Technologies allows users to start simple with printed route sheets or go high-tech with scanning of units serviced and integration of smartphone routing capabilities. It uses advanced mapping technologies to optimize route efficiencies with considerations for tank capacity, target schedules, and driver working hours. Digital signatures can be obtained on site, while the sites serviced instantly drop from the pending dispatch log. Information is easily accessible to office personnel while tracking drivers dynamically on street-level maps as they progress through their routes. (www.ritam.com)

January 2015 â&#x20AC;˘ Florida Water Resources Journal

ENGINEERING DIRECTORY

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EQUIPMENT & SERVICES DIRECTORY

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EQUIPMENT & SERVICES DIRECTORY

CLASSIFIEDS Positions Av ailable

CITY OF WINTER GARDEN – POSITIONS AVAILABLE The City of Winter Garden is currently accepting applications for the following positions:

Utilities Treatment Plant Operations Supervisor $53,039 - $74,631/yr. Assists in the admin & technical work in the mgmt, ops, & maint of the treatment plants. Class “A” Water lic. & a class “C” Wastewater lic. req. with 5 yrs supervisory exp.

Utilities Treatment Plant Will Call Operator $17.93-$27.82/hour. Part time. Must have passed the C drinking water or wastewater exam. Apply Online At: http://pompanobeachfl.gov Positions are open until filled. E/O/E

City of Vero Beach Electronics Technician Services, maintains, installs and performs preventative maintenance of electronic and electrical equipment throughout the water and sewer system. Must have thorough working knowledge of configuring, programming and maintenance of Modicon Programmable Logic Controllers and GE IFix HMI software version 5.5 and later. Visit website for complete job description, qualifications needed, and instruction to apply. $28.04 p/hr www.covb.org City of Vero Beach EOE/DFWP 772 978-4909

The Town of Hillsboro Beach is accepting applications for a Class C or higher Water Treatment Plant Operator or a trainee who has completed the DEP approved coursework. For application, please visit www.townofhillsborobeach.com.

January 2015 • Florida Water Resources Journal

- Collection Field Tech – I & II - Utilities Operator II - Water/Wastewater Plant Operator Class C - Distribution Field Tech – I & II - Public Service Worker I/Parks Please visit our website at www.cwgdn.com for complete job descriptions and employment application. Applications may be submitted online, emailed to jobs@cwgdn.com or faxed to 407-877-2795.

Assistant Director of Public Works (Utilities) The City of Hallandale Beach is now seeking an Assistant Director of Public Works (Utilities). Interested candidates meeting the minim requirements should apply online at http://www.hallandalebeachfl.gov/jobs.

Water Plant Positions The City of Hallandale Beach Water Pant is now seeking Part-Time Relief Water Plant Operators and a Public Service Worker II. Interested candidates meeting the minim requirements should apply online at http://www.hallandalebeachfl.gov/jobs.

DESTIN WATER USERS, INC WASTEWATER TREATMENT PLANT OPERATOR Destin Water Users, Inc. is currently taking applications for a Wastewater Treatment Plant Operator. This position is responsible for the overall operation and preventative maintenance of our 6MGD wastewater treatment plant and its associated equipment. Operators are subject to work shift work and holidays as assigned. A minimum of "C" license and a valid Florida Drivers License are required for consideration. DWU offers a generous benefits package and compensation will be commensurate with education and experience. To apply: please visit http://dwuinc.com/contact-us/career-opportunities/. EOE.

Treatment Plant Operator C-Wastewater Full-time, $33,863 annually, Open until Filled. All applicants should apply at: www.palmbayflorida.org

Lift Station Mechanic Ready for an exciting new chapter in your career? Join our team of Utility professionals at the City of Tavares, America’s Seaplane City, in beautiful Central Florida and enjoy these advantages! • Salary range: $26,500 - $39,750 • Excellent health, dental, life, disability and Florida Retirement System benefits • Generous time off and holiday plans • Positive and progressive work environment, focused on staff development The qualified candidate will possess: • High school graduate or accredited equivalent • Two (2) years experience in maintenance and repair of water/sewer pumps, motors, electrical panels and related equipment • Valid and insurable Florida Class “B” CDL • Florida FWPCOA Wastewater Collection license or ability to obtain within 6 months of hire For more detailed information and electronic access to our employment application, please visit our website at www.tavares.org.

Graduation from high school supplemented by college level course work in chemistry, biology, math, or related courses, and 1 to 2 years of experience in water purification or wastewater treatment plant operation and mechanical repair work; or any equivalent combination of training and experience which provides the required knowledge, skills and abilities. Must possess a valid Florida Driver’s License and have an acceptable driving record and maintain an acceptable driving record. SPECIAL REQUIREMENTS Level "C" certification as a wastewater treatment plant operator from the State of Florida Department of Environmental Resources.

Looking For a Job? The FWPCOA Job Placement Committee Can Help! Contact Joan E. Stokes at 407-293-9465 or fax 407-293-9943 for more information.

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APPLY TODAY! We welcome your resume or application in person or by mail to City of Tavares Human Resources, 201 East Main Street, Tavares, FL 32778, or by fax to 352-742-6351. We are an EOE, ADA, E-Verify and Drug-Free Workplace!

CDM Smith is Hiring in Florida! CDM Smith provides lasting and integrated solutions in water, environment, transportation, energy and facilities to public and private clients worldwide. As a full-service consulting, engineering, construction, and operations firm, we deliver exceptional client service, quality results and enduring value across the entire project life cycle. We are currently looking to fill Water/Wastewater Senior Project Manager openings in: • Jacksonville • Orlando

• Fort Myers • Miami • Broward/Palm Beach County

Successful candidates will have a Bachelors in engineering (Masters preferred), 10+ years of experience including project management experience, P.E. registration in Florida or ability to obtain quickly. We also have openings for a variety of other opportunities in our 10 Florida offices. For more information and to apply online, please visit www.cdmsmith.com. Those interested may also contact Will Vereen at vereenwp@cdmsmith.com. EOE Minorities/Females/Protected Veterans/Disabled Florida Water Resources Journal • January 2015

Certification Boulevard Answer Key From page 26 1. C) 30.2 lbs/day/ft

5. D) Decrease the RAS rate The total flow entering an aeration tank is Q plus QR (influent flow plus RAS flow). As the RAS flow is decreased, the contact time through the aeration tank zones is increased due to a reduction of the total flow entering the aeration tank.

Formula Total lbs/day entering the secondary clarifier ÷ total clarifier surface area, ft2 = lbs/day/ft2 Total lbs/day entering the secondary clarifier = (15.5 mgd + 10.075) x 3,200 mg/L x 8.34 lbs/gal = 682,546 lbs/day

6. C) Autotrophic There are two main groups of autotrophic bacteria that are responsible for the conversion of inorganic ammonia to nitrate. The first group, nitrosomonas (known as ammonia-oxidizing bacteria), convert ammonia to nitrite. The second group, nitrobacter (known as nitrite-oxidizing bacteria), convert nitrite to nitrate. The process of nitrification does not necessarily remove nitrogen from the wastewater; it only converts it to a more stable form.

Clarifier surface area = πr2 = 3.14 x (60 ft x 60 ft) = 11,304 ft2 = x 2 clarifiers = 22,608 ft2 682,546 lbs/day ÷ 22,608 ft2 = 30.19 lbs/day/ft2

2. C) Rotifer Beginning with the lowest life form, the microorganism indicators are amoebas, small flagellates, large flagellates, free swimming ciliates, stalk ciliates, rotifers, nematodes (worms), and water bears. Of the three indicators listed in the question, the rotifer is the highest life form in the activated sludge process.

7. B) 754 ft Length of weir, ft = circumference = πd (or 2πr) = 3.14 x 120 ft diameter x two tanks = 753.6 ft

8. B) 6 p.m.

3. C) Pounds of CBOD5 entering the aeration tank The term “loading” refers to the pounds of CBOD5 entering the aeration system. A highly loaded, or overloaded, plant typically has a high food-tomicroorganism (F/M) ratio and a low SRT.

4. C) Low aeration DO Because denitrification is an anoxic reaction, low dissolved oxygen levels in the aeration tank will typically result in the best (quickest) denitrification efficiency.

An unaerated stabilization pond is provided DO by activity from algae. During the sunlight hours, algae convert carbon dioxide to oxygen via photosynthesis. This activity increases the DO level in the pond; however, during the nonsunlight hours, oxygen is removed from the water and converted to carbon dioxide. This activity reduces the DO in the water. Of the available hours in this question, 6 p.m. is the time when photosynthesis will have been at its highest for the longest period of time, providing the most amount of oxygen into the water and the highest DO for the day.

Display Advertiser Index AWWA Membrane................47

FWPCOA Training ................49

Blue Planet..........................71

FWRC ............................10-13

B Magic ..............................40

Garney .................................5

CDM Smith..........................69

Gemini Group ......................15

CEU Challenge ....................17

GML Coating..................38, 62

Crom ..................................29

Hudson Pump......................35

Data Flow............................37

Hydro International ..............54

FSAWWA Drop Savers ........63

ISA ......................................46

FSAWWA Operators Awards 55

McKim & Creed ..................16

FSAWWA Tallahassee Day ..63

Polston Technology..............44

FSAWWA Training ................43

Reiss Engineering..................7

FWEA Collection Awards ......64

Schwing Bioset....................25

FWEA Ops Challenge ..........39

Stacon...................................2

FWPCOA Online Training ......31

TREEO ................................27

FWPCOA Short School ........45

Xylem .................................72

January 2015 • Florida Water Resources Journal

9. A) About 27 ft per min Ft per minute = cu ft per minute (cfm) ÷ cross sectional area in ft2 = 1,500 gpm x 1,400 minutes per day = 2,160,000 gpd ÷ 1,000,000 = 2.16 mgd cfm = mgd x 92.84 cfm per mgd = 2.16 mgd x 92.84 cfm per mgd = 200.53 cfm cross sectional area, ft2 = width, ft x depth, ft = 6 ft x (15 in. ÷ 12 in. per ft) = 7.5 ft2 ft per minute = 200.53 cfm ÷ 7.5 ft2 = 26.7 ft per minute

10. B) Characteristics of the influent wastewater The characteristics of the influent (including the flow rate, concentrations of CBOD5, total suspended solids, fats, oil and grease, temperature, and other criteria), probably have the largest impact on the overall performance of a primary clarifier. Certainly, the removal rate and frequency of the primary sludge also has an impact on the performance efficiency and quality of the primary effluent produced.

Editorial Calendar January ........Wastewater Treatment February ......Water Supply; Alternative Sources March ..........Energy Efficiency; Environmental Stewardship April..............Conservation and Reuse May ..............Operations and Utilities Management; Florida Water Resources Conference June ............Biosolids Management and Bioenergy Production July ..............Stormwater Management; Emerging Technologies; FWRC Review August..........Disinfection; Water Quality September....Emerging Issues; Water Resources Management October ........New Facilities, Expansions, and Upgrades November ....Water Treatment December ....Distribution and Collection Technical articles are usually scheduled several months in advance and are due 60 days before the issue month (for example, January 1 for the March issue). The closing date for display ad and directory card reservations, notices, announcements, upcoming events, and everything else including classified ads, is 30 days before the issue month (for example, September 1 for the October issue). For further information on submittal requirements, guidelines for writers, advertising rates and conditions, and ad dimensions, as well as the most recent notices, announcements, and classified advertisements, go to www.fwrj.com or call 352-241-6006.