LMP Post-Construction Stormwater Control Measures

Page 1

5. Post-Construction Stormwater Control Measures CHAPTER CONTENTS INTRODUCTION

71

STORMWATER CONDITIONS AT AUBURN UNIVERSITY

71

STORMWATER MANAGEMENT INTEGRATED GOALS

73

STORMWATER BEST MANAGEMENT PRACTICES IMPLEMENTATION

73

STORMWATER MANAGEMENT PRELIMINARY BEST MANAGEMENT PRACTICE IDEAS

75


gg

W WWWW West Magnolia Ave W g W WW WgWW WWWWg Wg W gWWW WW W WWW W ggW WWW g W WW W WW g WWg W Wg gg g g g W g W g W W W g g g g g g g gg g ggggg Wg g Wg W g g ggg WW g W W WW WW g W gWg WW g gW g ggWWWWW g g gg W gg gggg g WWWW W WWW Wgg g g W W g W W W g W g g g g W W W gg ggggg ggW WW W WW W gggggg ggW g W gg g g W WWg Wgg g Wg g g W W W W W W g WW WWW g g W W g g g W W W g W W g WWW W WW W W W gg ggW WW ggWg ggW g gg W W gWWWWWWW g WW g g g gW gW W W gg g W Wgg g g g g W g g W W g g g g W g g g W g g g g g g g g gg WW gW W gg g g g W W WWW W W W gWWWg gWWggWW ggWg Wg g gggg gggg ggg Wg W WW Wgg g gWgg g gg g W g g W W WW W W W g g g W g g g W W g g W W g W g g g g W g g g Wg g gW WW gggg WW WWWW g g gggg g W W g g WWgWg g g g g WWg g WWWW g W g Wg W g gg Wg g gg g gggWWgW gWg g WgW Wggg ggg WWWg gg W g g ggg g g WW W gg gg g WWWWW WWg gg g g gggggg gg Wg g ggg g W W g g gWggg g g g g Wg g g W g g g W W g W g g g g g g W g g W W g g g W g g g g g g g g W g W W g W W g g W W g g g W g W W W W g W W g g g g W W g g W g WW W W WW W W ggg W gW g Wg W g gggg g W ggg g g ggg gg gg WW gg gggg gg g WW gW ggg W gg g gg gg g g gg ggg gg ggggg gWW WgW g gg gW gWg g W W WW W Wgggg g g g g g g g g Wg g W Wg g g g g W g g WW W W W W W W g g g g ggg gg W g gW W g WW gg Wg ggWgW g ggWgg gW gW ggWWW W WWgggWgW W Wg gW ggggg gWg WW W gg g g W W W W g g W g W W W g g gg WW g gW g g WgW W ggg g gg gWgg W Wg g g g W ggW WW g g gggggWWgg g gggg W gggg WW W ggg g W W W gW g gg WgW WW Wg g gg g g W W W gg WW W W W W W g g Wg ggg g W g Wg g W WWgWW g gW g gWW gggWgWggg gg W Wg g WWggggg W W g g W W g g W g g g W g g g g g W g W WW g W W g gg WW WW g g ggg gW gggWgWW ggWgWW WWg g g g gg g gW W g ggg W WWW Wgg gW g gg W gg ggg gg gggW gW WgWgWg g W WW gg g gW g g gWg g g g g g gW W g W W g g g g W g gg g ggg g gg Wg Wg g g g W W g g g W g gg g g gg g g gg g W g g ggW W g gW W g gg g WW g gg gWg gg W W gg gg gg g ggg g W Wg g g g WW g g ggWg g gW gg g gW gW gg W W g W g g g gg gg g W g W WW W gW gW gW gg WW W ggWW g g g g ggg gg g g W g W g g W W g g WW g g WWW W g g g g W g g gg WW gg WW g gg gg W ggg gg WW W g WW g g g g g g W g WW W gg WW W W W W W W W W W WW ggg g g ggg W W gggg W W WWW W g W g WWW WW W W WW WWg g g W W gggg g WW W W W W g W g Wg gW WW g gWWW gggg WWW WW WW W W WWW WWW g gWgW W WgWg Wg g WW W g W g gg gWg g gg WW W W gg W W g g g WW g g g W g gW W W WW g g Wg WWW g g WgggW ggg g g gg g g WW g WWWWW WWW WWW WWg g gW WW WW Wg g Wg W WW W gWgW Wg g g WW W gW g W W gg WW W gg Wg g g W WW W g g W ggg gg W WgWgg g W W W g gW gWWWgg g W g g WW g g ggg W g g gggg W gW g W ggW gg gWW g g g gW g g W WW g gg g gW WW WWg gg g W gg gWWW W W W g W g W W

gg

INTRODUCTION

W

W Wg W

gg g g g g g

g W g

g W

g

S. Donahue Dr

Auburn University is forward thinking in its approach to evaluate the opportunity for integrated stormwater management early and in full collaboration with the larger Campus Master Planning and Landscape Master Planning efforts. There are opportunities to use the landscape as stormwater infrastructure, and to incorporate stormwater infrastructure in the landscape to contribute to flood protection, resource protection, and regulatory stormwater management compliance goals while maintaining the aesthetic goals for the intended land uses. This integrated approach will allow for evaluation of big picture cost savings as larger stormwater management projects and goals may be incorporated into the overall campus plans rather than attempting to apply these on a project by project basis after other plans are set. This will reduce the potential for future constraints and lost opportunities.

South College Street

In urbanized and developed areas, stormwater that runs off of impervious areas such as rooftops, and pavement during rain events typically carry contaminants such as sediment, bacteria and nutrients that were accumulated on the surface. These typically piped flows discharge the runoff faster and with more volume than would occur if the rainwater infiltrated naturally through the soils. This often causes erosion and scouring in the receiving location. This is the case at Auburn University, where these larger volumes of stormwater and associated sediments and pollutants typically discharge directly to Parkerson Mill Creek. The stream has become eroded, widened and degraded in terms of water quality and habitat. It is estimated that 85% of the stream channel within campus boundaries is in poor condition, and with much of the original stream in pipes, the natural presence of the stream as a valued resource /natural amenity within the core campus has been lost.

STORMWATER CONDITIONS AT AUBURN UNIVERSITY

In recent years the University has begun including stormwater best management practices in the design of new roadway and building projects as well as a few stormwater specific demonstration projects. These include a vegetated detention basin at the intersection of Samford Avenue and Wire Road; terraced parking with integrated biofiltration swales at the West Thach parking lot (Figure 5-3); a vegetated detention basin for the parking lot runoff for the Band Practice field; numerous underground detention structures at new developments designed to discharge at pre-development levels; and a pervious concrete installation at the arboretum (Figure 5-4). The University has recognized that there is currently no cohesive plan, guidance document, or performance standards in place to assist in consistent implementation of these types of post construction stormwater best management practices (BMPs). Part of the current Landscape Master Plan process is focused on providing recommendations for post construction stormwater management BMPs and a mechanism for implementation.

Lem Morrison Drive

W W

W Wg

WW

W

WW

W

W

M

ill C

W WW W

ggggg g g W W ggWWg g gWW WW gW gW Wg W W g g g gggWW

gW gg

g

ggg ggg g g WW

W W W WW W W g W Wg

g W WW Wg W W

WW W

WW

re ek

WW

gg W W

on

Stormwater at the University is managed mostly through a closed piped drainage system that receives runoff via large surface curb inlets. Pavement and rooftop runoff typically discharges directly to the piped system and pre-treatment methods are not typically in place for older developed areas. As previously mentioned, there are two large subsurface detention areas located on the northern portion of Campus at the City/Campus limit where stormwater from the City enters the campus drainage system and continues in a 60-inch pipe on to the open section of Parkerson Mill Creek downstream (Figure 5-1). While there are four (4) trash racks/screens installed within the closed pipe drainage system, stormwater pre-treatment practices such as; forebays, deep sumps, or vegetated treatment/ filtering methods are not generally incorporated into the system.

W

er s

New developments on campus are required by the Alabama Department of Environmental Management (ADEM) to provide stormwater storage structures with controlled discharges, but the majority of developed areas on campus were constructed before these requirements were in place. These combined factors have resulted in the discharge of increased stormwater volumes to the collection system including the culverted portions of Parkerson Mill Creek and ultimately to the open channel sections downstream. Significant impacts are evident along the stream corridor. These are outlined in the Wetland Resources Report prepared for the University.

WW W

Pa rk

The most heavily developed urbanized areas of Auburn University (Core Campus) are located in the headwaters of the Parkerson Mill Creek Watershed. Portions of the original stream and its tributaries are piped beneath the core campus (See Figure 5-1). While this area has the highest impervious percentage on campus, it employs only two (2) significant stormwater management areas. The 2 large stormwater detention basins (providing 1.2 million gallons and 0.8 million gallons of storage) are positioned in the upper reaches of the campus basin and were designed with the intent of controlling and storing stormwater running onto campus via the City of Auburn’s collection system.

W

W W

W

gg g gW g g g gg g g gW gWg g g g g gW g

W g gW gg

W WW

g ggg gg g gg g W gg WW gg WW g

W

g W

LEGEND Outfalls

AUBURN UNIVERSITY STORMWATER MANAGEMENT EXISTING STORMWATER DRAINAGE SYSTEM

o

g

Catch Basins

W

Drain Manholes Culverted Channel Drain Lines

0

500

1,000

Feet 2,000

Sources: VHB, Sasaki, KREBs

Figure 5-1. Existing Stormwater Drainage System Diagram 71

Auburn University Landscape Master Plan, Comprehensive Campus Master Plan Update 2014


The University has already completed a new Sedimentation and Erosion Control Guidance document to assist contractors in preventing the discharge of sediment contaminated runoff during construction activities. This has resulted in decreases of sediment loads to Parkerson Mill Creek. The Landscape Services Department has also implemented a sustainable practices program that includes: Plant debris recycling Mulching mowers Hand pruning practices Slow release fertilizer applications Integrated pest management (IPM) for the reduction of pesticides, and an impressive Landscape Water Management Plan to reduce water consumption Some areas on campus do not have stormwater management success stories to tell and it has been recognized that standardization of practices and guidance on materials would help to encourage good practices for construction projects as well as emergency repairs and ongoing maintenance activities. For example, when severe stream bank erosion at the Forestry and Wildlife Sciences Building, threatened the integrity of the building, stream bank erosion was so severe that concern over the structural integrity of the building led to concrete being dumped into the stream channel to stop future erosion (Figure 5-6). While this emergency repair did stabilize the embankment, it was not in keeping with common environmentally protective stream bank stabilization practices that also strive to protect wildlife habitat, stream morphology and aesthetics. An effective procedures document may have prevented this choice of remedy. Appendix A includes a figure entitled “STORMWATER DRAINAGE - INITIAL SITE OBSERVATIONS” that identifies existing stormwater management features on campus, as well as preliminary thoughts relative to opportunities for enhancing and expanding stormwater management through retro-fits, or new practices. This figure was produced as a preliminary planning document, coordinated with the Landscape Master Plan development process, and was the first step towards the development of the Post Construction Stormwater Management Manual.

Figure 5-2. Typical stormwater curb inlet

This Manual will be the cohesive plan that defines the desired practices to be used consistently on campus for achieving the defined stormwater management goals.

Figure 5-3. West Thach parking lot terraces with grassed biofiltration swales

Post-Construction Stormwater Control Measures

Figure 5-4. Pervious concrete at the Arboretum

Figure 5-5. Successful sediment control basin, intersection of Wire Road and Samford Avenue

Figure 5-6. Concrete placement to prevent further stream bank erosion 72


STORMWATER MANAGEMENT INTEGRATED GOALS Goals of the Auburn University stormwater management program include the following key components: 1. Safe Stormwater Conveyance and Flood Protection

rates input from the many departments and personnel associated with campus stormwater management The following section describes some of the key BMP recommendations and implementation plan for the goals and tasks as stated above. These have been incorporated into the Post Construction Stormwater Management Manual.

2. Stormwater Runoff Quality Control 3. Stormwater Runoff Volume Reduction 4. Regulatory Compliance 5. Local Collaboration 6. Education and Outreach 7. Standardization of Stormwater Best Management Practices 8. Standardization of Operation and Maintenance Guidelines 9. Formalization and implementation of a Stormwater Site Plan Review Process 10. Integrated Data Management and Record keeping Recommended actions to achieve these goals include: 1.

Develop Flood Plain Management and Protection Plans – for human safety, property and resource protection.

2.

Develop Storm Drain System Design Standards - for storm drain conveyance system design, volume and velocity control specifications.

3.

Comply with NPDES Stormwater Permit -fully implement the 6 minimum measures.

4. Comply with Alabama State Water Quality Criteria – specifically the pathogen TMDL for Parkerson Mill Creek. 5.

Implement Sedimentation and Erosion Control Guidelines – implementation of Auburn University construction activity sedimentation erosion control procedures as well as overall volume/velocity reduction goals/requirements.

6.

Standardize Stormwater BMP Design Selections - recommendations for BMP designs for various campus areas.

7.

Standardize Stormwater BMP Design Materials and Methods – recommendations for the materials and design criteria for BMPs

8.

Standardize Design/Review process for Stormwater Management - applies to stormwater management components associated with any new or redevelopment on campus.

9.

Framework/outline of the Mechanisms for Implementation – this will require ongoing input and development by University Team and utilization of readily available guidelines, procedures and programs. - Implement Standardized O&M Procedures – reference to the O&M document that will standardize maintenance goals, processes and schedules for stormwater management BMPs, including training and related activities.

10. Record keeping – evaluation of options and development of a recommendation for setting up a framework for central record keeping processes that incorpo-

73

STORMWATER BEST MANAGEMENT PRACTICES IMPLEMENTATION The goal of the Campus Landscape Master Plan is to improve the character and increase the use of vegetation across the campus. Many stormwater best management practices (BMPs) include using vegetation. Often the only difference between a landscaped island and a stormwater management BMP is that in order to improve stormwater management, the landscape island would be designed as a depression to encourage more stormwater to collect there. By integrating the two efforts, landscape planning and stormwater management planning, the University can achieve their goal of having a cohesive landscape plan and meet the regulatory requirements of protecting Parkerson Mill Creek at the same time and with the same practices. Stormwater BMPs can range from vegetated practices to maintenance guidelines. Table 5-2 outlines BMPs which have been selected as appropriate for Auburn University. They are divided into structural practices (post construction and construction related) and nonstructural practices (educational, operation and maintenance and program/evaluations). The Table provides a brief description of the practice, the stormwater management goal it supports, and if available, the estimated pollutant removal of the practice based on the best available local resource data. General cost estimates and general operation and maintenance requirements are provided. Also included in the table is the recommended location for the practice in terms of the Landscape Master Plan.

Figure 5-5. Inlet could be retrofitted with a tree box filter or biofiltration swale prior to discharge into close pipe drainage system.

Some of the key structural practices that address stormwater management and are selected based on their look and feel in the campus landscape are described below. Overall the goal of all stormwater BMPs proposed for Auburn University are to improve the quality and reduce the quantity of stormwater reaching Parkerson Mill Creek and other water resources in Auburn. This may be accomplished in part by placing retro-fits in existing areas, as well as designing new areas. Figures 5-5 through 5-10 below show typical conditions on campus that represent good opportunities to retrofit existing conditions to better manage stormwater runoff. A description of a few key BMPs identified as focal points of the recommended plan proposed for the University are as follows: Bioretention Bioretention facilities, often referred to in the past as “Rain Gardens” are planting areas installed in shallow basins in which the stormwater runoff is treated by filtering through the basin soils. They may be used in poor soils with the use of underdrains and they may be designed visual landscape amenities as well as stormwater BMPs. They may be designed to be more naturalistic looking with a goal to blend into a more wild landscape or more manicured and area suitable for interspersion through the campus. Examples photos are shown in Table 5-2.

Figure 5-8. Vegetated Island could be retrofitted to be a depressed bioretention area with storage and treatment

Auburn University Landscape Master Plan, Comprehensive Campus Master Plan Update 2014


Permeable Pavement Pervious pavement allows for high rates of rainfall to infiltrate into the sub base layers of the pavement system, and if appropriate the native soils. Even if sub soils are not appropriate for infiltration, permeable pavements can be designed with underdrains and will provide water quality treatment, peak runoff rate reductions, temperature control and volume reductions. Permeable pavements are available as concrete, asphalt, or interlocking pavers. While the University has tried each of these permeable pavement types with limited success, this practice is a viable option for achieving the goals for stormwater management and landscape improvement simultaneously. A comparison of advantages and disadvantages is shown below in table 5-1:

aeration of the soil will decrease the density/compaction of the turf and soil, and provide additional assistance with infiltration/filtration of stormwater through the upper layer of the soil strata. Soil amendments help to provide water quality benefits, not only by increasing the infiltration capacity of the soil, but also by: Filtering and breaking down potential pollutants Immobilizing and degrading pollutants by holding potential pollutants in place so that soil microbes can decompose them Reducing the need for fertilizers, pesticides and irrigation by supplying more nutrients and a slow-release to plants Holding more rainwater on site, decreasing runoff, and providing increased soil moisture and infiltration capacity Increasing soil stability, leading to less potential erosion Providing added protection to groundwater resources, especially from heavy metal contamination Reducing thermal pollution by maintaining runoff in the soil and on site longer (LID Center, 2002) It is recommended that soil amendment be used campus wide as much as possible. Implementation

Table 5-1. Pavement comparison table.

Subsurface Storage Figure 5-9. Impervious pavers at the stadium. Future pavement patterns could be completed with permeable interlocking concrete pavement.

The reduction of stormwater peak flow rates and volumes is a primary goal for stormwater management at the University, thus detention storage of stormwater is a high priority BMP option. Because much of the core campus area is developed and surface land area is valuable for building and open space needs, subsurface storage is likely preferred to large surface detention areas. While the cost for subsurface storage may be high, if structural containment devices are used, such as concrete tanks, other feasible options such as rock storage areas beneath permeable pavement parking lots, or plastic chamber systems should be considered. It should be noted that the use of subsurface storage, as opposed to surface storage areas, results in no net loss of surface land area and a decrease in the need for piped infrastructure in the case of permeable pavement systems and may result in cost benefits. While wet pond and dry detention basins are included in the BMP selection table, the preference for the core campus area would likely be sub-surface storage. These planning stage efforts looked at opportunities for larger more regionalized storage locations rather than multiple small locations throughout. These are shown on the attached Plan for Proposed Stormwater BMPs. Soil Amendment

Figure 5-10. Example of a permeable interlocking concrete pavers installation.

Post-Construction Stormwater Control Measures

Infiltration and filtration of stormwater runoff can be promoted by amending the topsoil layer of soils on campus with sand, compost, mulch topsoil, lime and gypsum. The amended soil allows for greater absorption and retention of rainwater. This reduces runoff, and also contributes to improved plant health and vigor which also reduces runoff. Also,

The University has prepared a Post Construction Stormwater Management Manual and an Operations and Maintenance Manual for Stormwater Management related activities at the University. These two documents are the first step at initiating a cohesive process for stormwater management on the campus. The Post-Construction Manual is intended to be the guiding document for selecting and implementing stormwater management practices when new or redevelopment projects occur on University Property. A preliminary concept for implementation of some of the recommended stormwater BMPs was prepared during the planning stages and is titled “Stormwater Management – Preliminary Best Management Practice Ideas” (See Table 5-2). See Figure 5-11 for a plan diagram showing potential locations for the Stormwater Preliminary Best Management Practice Ideas. Together, these documents are the framework for a living document that can move forward and develop as it receives input from the variety of departments and personnel associated with stormwater management on campus. These documents are meant to change and develop to become more complete over time as Alabama develops a statewide stormwater handbook, and as campus planning processes proceed. The documents are not intended to be final documents, but rather the framework and first steps at preparing a stormwater program with key goals and procedures identified, within the context of the larger campus master planning effort and landscape planning effort. The documents reference already available stormwater management practice design information as developed by the City of Auburn, and other agencies that have developed guidance material. These resources are referenced throughout the stormwater documents.

74


STORMWATER MANAGEMENT - PRELIMINARY BEST MANAGEMENT PRACTICE IDEAS

West Magnolia Ave

V U 267

South College Street

V U 14

W. Samford Ave

S. Donahue Dr

Sh u g J

ord an Pa rk w

Lem Morrison Drive

Pa

rk

er

so

n

M

ill

Cr

ee

k

ay

Legend

Bioretention Stream Daylighting Dump Station Surface Detention Basin Permeable Pavement Parking Green Roof Stormwater Wetland Underground Detention Riparian Buffer

Figure 5-11. Campus Best Management Practices Diagram 75

Auburn University Landscape Master Plan, Comprehensive Campus Master Plan Update 2014


TABLE 5-2. STORMWATER BEST MANAGEMENT PRACTICES

PERFORMANCE METRICS1 STORMWATER MANAGEMENT PRACTICE

DESCRIPTION

MANAGEMENT GOALS & COMPLIANCE1

APPLICATION AT AUBURN UNIVERSITY

POLLUTANT REMOVAL1

LANDSCAPE TYPES (AS DEFINED BY SASAKI)

TSS: 80% Nutrients: 60% Metals: 90% Pathogens: 90%6

Subsurface structures could be located in a variety of locations.

Medium Annual inspection, depending on accumulation of materials may need a vactor for cleaning.

Civic Spaces Pedestrian Concourses Quadrangles Building-related Plazas Gardens and Courtyards Sports Landscapes Parking Services Landscapes

Medium Annual inspection, depending on accumulation of materials may need a vactor for cleaning.

TYPICAL BUDGET ALLOWANCE

RELATIVE LEVEL OF MAINTENANCE

Structural Best Management Practices (BMPS) Post Construction BMPS Subsurface Infiltration Systems Subsurface infiltration systems may be comprised of: t open bottom concrete vaults/ tanks/chambers t perforated pre-cast concrete vaults/ tanks/chambers t perforated plastic storage chambers t series of perforated plastic pipes

TMDL Compliance MS4 Compliance Volume Reduction Flow Reduction Temperature Reduction

Figure 5-12

Underground Detention

Figure 5-13

Underground detention is typically precast concrete vaults/tanks/chambers or plastic storage chambers or pipes that are sealed. They do not infiltrate into the subsurface soils, but have an outlet control structure similar to a surface detention basin that holds the water temporarily and lets the water leave the storage area at a slower controlled rate via small outlets designed to mimic natural flow patterns.

MS4 Compliance Volume Reduction Flow Reduction

The process of capturing stormwater runoff typically from roofs, terrace, walkways, turf areas, and sometimes from pavements in subsurface storage chambers (“cisterns”) for re-use. Collected rainwater often used for nearby landscape irrigation and nonpotable demands.

MS4 Compliance Volume Reduction Flow Reduction

Rainwater Harvesting Volume Reduction TSS reduction Nutrient removal if reused as irrigation water

Sports Landscapes Agricultural Landscapes and Ag Heritage Park Building-related Plazas Gardens and Courtyards

$4–$6/gallon of storage depending on site geometry and system configuration (pumping, filtration, distribution, etc.).

Low Inspection of equipment, cleaning of filters and sediment accumulation collection area. Replacement of pumping systems may be required every 10-15 years.

Figure 5-14

Post-Construction Stormwater Control Measures

76


APPLICATION AT AUBURN UNIVERSITY

PERFORMANCE METRICS1 STORMWATER MANAGEMENT PRACTICE

DESCRIPTION

MANAGEMENT GOALS & COMPLIANCE1

POLLUTANT REMOVAL1

LANDSCAPE TYPES (AS DEFINED BY SASAKI)

TYPICAL BUDGET ALLOWANCE

RELATIVE LEVEL OF MAINTENANCE

TMDL Compliance

TSS reduction

Stream Corridors

$150–$400 per linear foot depending on nature of work.

Low Self sustaining after initial grow in of plant materials.

TSS: 85% Nutrients: 40% Metals: 50% Pathogens: 70% Temperature control6

Unmanaged Areas Agricultural Landscapes and Ag Heritage Park Parking and Service Landscapes The Arboretum Managed Natural Areas

$5,000/acre for tublings on 10’ centers with tree tube protection; substantially more for container grown or caliper grade specimens.

Low Monitoring ecological health and function of the buffer. Remove invasive species and mitigate for erosion or other damage.

Flow Reduction Temperature Control

All

Cost dependent on type, number and size of tree.

Low Self sustaining after planting. Using permeable materials near or around the tree/roots will ensure greater plant health. Leaving natural leaf litter as mulch also improves moisture retention and provides nutrients as it decays. Minor cleanup for visual purposes, or for branch/leaf litter that falls on pavements or pathways.

Structural Best Management Practices (BMPS) Post Construction BMPS Stream Restoration Restoration of natural channel dimensions, pattern and profile of channel designed to establish a stable channel and floodplain for the developed watershed conditions. May include instream rock structures and riparian plant installations.

PMC WMP Action Plan Volume & Flow Attenuation Aquatic/riparian habitat improvement

Figure 5-15

Riparian Buffer Mature vegetated ecosystem adjacent to surface water, between 35-100 feet wide from each bank of the water body. Buffer serves to filter pollutants from overland stormwater flow. Buffers also act to slow (reducing erosion) and cool stormwater flows before reaching the surface waters. Buffers also provide exceptional habitat for wildlife and aquatic organisms.6

MS4 Compliance

Specific benefits related to stormwater is canopy that shades the pavement and keeps temperatures cooler. Leaf interception reduces stormwater runoff. When permeable pavements or infiltration practices are nearby, nutrients from infiltrated runoff support beneficial growth of trees. Leaf litter can remain naturally as mulch instead of applying mulch from other sources to retain moisture and provide nutrients.

Temperature reduction

PMC WMP Action Plan Volume & Flow attenuation Habitat improvement6

Figure 5-16

Increased Tree Canopy

Figure 5-15

77

Volume & Flow reduction Aquatic/riparian habitat improvement

Auburn University Landscape Master Plan, Comprehensive Campus Master Plan Update 2014


PERFORMANCE METRICS1 STORMWATER MANAGEMENT PRACTICE

DESCRIPTION

MANAGEMENT GOALS & COMPLIANCE1

APPLICATION AT AUBURN UNIVERSITY

POLLUTANT REMOVAL1

LANDSCAPE TYPES (AS DEFINED BY SASAKI)

TYPICAL BUDGET ALLOWANCE

RELATIVE LEVEL OF MAINTENANCE

Flow Reduction Temperature control

Selected new campus rooftops

Materials $10–$30 s.f. (not including installation)

Low Requires irrigation and fertilization in the first year only for initial plant growth, then becomes self sustaining. Requires some landscape maintenance, removal of dead vegetation, invasives and inspection of roof. EPA Fact Sheet estimate $0.75–$1.50 s.f. annual maintenance cost.

TSS Reduction Volume Reduction

All Construction Projects Exposed soil locations, stockpiles and slopes

Erosion control prices vary with project and BMPs used.

Updates as necessary.

Civic Spaces Front Yards Pedestrian Concourses Building-related Plazas Gardens and Courtyards Interstitial / Connective Spaces Sports Landscapes The Arboretum

Varies based upon desired communication program and protocols.

Structural Best Management Practices (BMPS) Post Construction BMPS Green Roofs Utilize the simpler design for shallow “extensive” green roofs in campus areas. These may be designed on sloped or flat roofs and are recommended for new construction rather than a retrofit. The design is primarily for smaller storm interception rather than for large stormwater volume storage. Green Roofs are effective to delay flows and utilize nutrients from atmospheric deposition.

Figure 5-18

MS4 Compliance PMC WMP Action Plan for Volume & Flow reduction practices

Construction Activity Erosion and Sediment Control BMPS Erosion and Sedimentation Control Implementation of the University of Auburn Erosion and Sedimentation Control Practices (Auburn University Design and Construction Standards, Section G10–Site Preparation, Part 9.2– Erosion and Sediment Control Plan)

MS4 Permit Compliance PMC WMP Action Plan

Figure 5-19

Non-Structural Best Management Practices (BMPs) Educational BMPs Signage Signage and other communication means regarding BMPs, their description, purpose and use as well as signage describing watershed water quality goals as related to campus stormwater management practices.

MS4 Permit Compliance PMC WMP Action Plan

Figure 5-20

Post-Construction Stormwater Control Measures

78


PERFORMANCE METRICS1 STORMWATER MANAGEMENT PRACTICE

DESCRIPTION

MANAGEMENT GOALS & COMPLIANCE1

POLLUTANT REMOVAL1

APPLICATION AT AUBURN UNIVERSITY LANDSCAPE TYPES (AS DEFINED BY SASAKI)

TYPICAL BUDGET ALLOWANCE

RELATIVE LEVEL OF MAINTENANCE

PMC WMP Action Plan estimated $7,500 plus staff time for total football program education. This estimate recommends additional funding to support more signage and inclusion of information in all sports related media venues in addition to on-site training of event planning/ management staff.

Updates as necessary.

Non-Structural Best Management Practices (BMPs) Educational BMPs Game Day Education Provide educational information for football game attendees and program workers/students etc. regarding critical stormwater pollution prevention, stream protection goals and behaviors needed to achieve goals.

MS4 Permit Compliance

Provide waste dump stations for RV users on campus.

TMDL Compliance

PMC WMP Action Plan

Potential for pathogen decrease, TSS decrease and erosion/ sedimentation decrease.

Figure 5-21

RV Waste Dump Station

MS4 Permit Compliance

Significant pathogen removal potential TMDL compliance.

Sports Landscapes Parking and Service Landscapes

Potential for pathogen decrease, TSS decrease and erosion/ sedimentation decrease.

Campus-wide

Varies depending on size, type, and location.

PMC WMP Action Plan

Figure 5-22

General Housekeeping Best Practices Training University employees should receive regular training on housekeeping best pracitices for all facilities activities. This may include vehicle and equipment maintenance practices, landscape practices, and general pollution prevention practices. Good housekeeping practices can greatly eliminate pollutant sources to water resources.

MS4 Permit Compliance

Updates as necessary.

Figure 5-23

79

Auburn University Landscape Master Plan, Comprehensive Campus Master Plan Update 2014


APPLICATION AT AUBURN UNIVERSITY

PERFORMANCE METRICS1 STORMWATER MANAGEMENT PRACTICE

DESCRIPTION

MANAGEMENT GOALS & COMPLIANCE1

POLLUTANT REMOVAL1

LANDSCAPE TYPES (AS DEFINED BY SASAKI)

Significant pathogen removal potential TMDL compliance.

Campus-wide

Updates as necessary.

All pavements

Twice per year minimum for parking and ancillary roads. More frequent, to be determined by deposition on heavily trafficked and utilized pavements.

All

Recommend to inspect annually for three years after entire stormwater maintenance plan is in place to determine long term cleaning schedule. After street sweeping is in place, the need for cleaning structures will likely reduce and cleaning can be planned based on documented buildup.

TYPICAL BUDGET ALLOWANCE

RELATIVE LEVEL OF MAINTENANCE

Non-Structural Best Management Practices (BMPs) Educational BMPs Pet Waste Management Education and outreach regarding proper pet waste management on campus.

TMDL Compliance MS4 Permit Compliance PMC WMP Action Plan

Figure 5-24

Maintenance/Management BMPs Street Sweeping Use of vacuum sweepers preferred for permeable pavements. Regular rotary brush sweepers acceptable for standard pavement.

TMDL Compliance MS4 Permit Compliance

Figure 5-25

Catch Basin Cleaning Use of vactor truck apparatus rather than clamshell cleaning for all catch basin/manhole cleaning.

TMDL Compliance MS4 Permit Compliance

Figure 5-26

Post-Construction Stormwater Control Measures

80


PERFORMANCE METRICS1 STORMWATER MANAGEMENT PRACTICE

DESCRIPTION

MANAGEMENT GOALS & COMPLIANCE1

POLLUTANT REMOVAL1

APPLICATION AT AUBURN UNIVERSITY LANDSCAPE TYPES (AS DEFINED BY SASAKI)

TYPICAL BUDGET ALLOWANCE

RELATIVE LEVEL OF MAINTENANCE

Non-Structural Best Management Practices (BMPs) Maintenance/Management BMPs Landscape Waste Management Management plan for yard waste and landscape materials (including fertilizer/herbicide) to be prepared and implemented as part of the campus wide stormwater management plan.

TMDL Compliance

Continue to implement the Landscape Services’ comprehensive program of sustainable landscaping that limits the use of herbicides, pesticides and fertilizers and manages the storage and use of these products. Avoid overwatering and choose native plants that require less water and fertilizer. Avoid applying herbicides, pesticides and fertilizers in wet weather conditions when the materials will quickly runoff into receiving waters.

Implement a campus-wide program to amend all disturbed soils with organic materials (preferably from the University’s yard waste compost). Also helpful with existing soils, planted areas, and especially sloped areas.Amending soils will allow healthy vegetation growth and prevent erosion.

Facilities/Management Locations

Updates as necessary.

MS4 Permit Compliance

Agricultural Lanscapes and Ag Heritage Park

Updates as necessary.

TMDL Compliance

Campus-wide

Updates as necessary.

MS4 Permit Compliance

Figure 5-25

Landscape Product Management

Figure 5-28

Soil Amendment

Figure 5-29

81

Auburn University Landscape Master Plan, Comprehensive Campus Master Plan Update 2014


APPLICATION AT AUBURN UNIVERSITY

PERFORMANCE METRICS1 STORMWATER MANAGEMENT PRACTICE

DESCRIPTION

MANAGEMENT GOALS & COMPLIANCE1

POLLUTANT REMOVAL1

LANDSCAPE TYPES (AS DEFINED BY SASAKI)

TYPICAL BUDGET ALLOWANCE

RELATIVE LEVEL OF MAINTENANCE

Non-Structural Best Management Practices (BMPs) Maintenance/Management BMPs Ground Cover

Figure 5-30

Landscaped areas across the Campus should include ground cover vegetation instead of grass or mulch as appropriate. Native ground cover has many benefits over grass or mulch. Ground cover can help to capture and slow stormwater runoff, acting as volume control assistance and assisting in eliminating erosion and also requires less maintenance than grass.

Campus-wide

Updates as necessary.

Litter Trash Containers Solid waste litter from events and daily campus activities impair water quality. Evaluation of additional trash container locations and a clear collection program will help reduce litter transported to PMC.

TMDL Compliance

All

MS4 Permit Compliance

PMC WMP estimates $300 per new trash container.

Trash collection schedule per events and routine maintenance on campus. Evaluate plastic/paper recycling program ease of use in outdoor spaces.

Figure 5-31

Dumpster Use/Maintenance

Figure 5-32

Post-Construction Stormwater Control Measures

Waste materials that may leak nutrients, contaminants or hazardous fluids should not be placed in open dumpsters. Dumpsters should be covered and not exposed to rain, or allowed to drain fluids from the bottom. Enclosure and regular maintenance of all dumpsters is recommended to prevent leakage from the interior of th d t

Campus-wide

Updates as necessary.

82


PERFORMANCE METRICS1 STORMWATER MANAGEMENT PRACTICE

DESCRIPTION

MANAGEMENT GOALS & COMPLIANCE1

POLLUTANT REMOVAL1

APPLICATION AT AUBURN UNIVERSITY LANDSCAPE TYPES (AS DEFINED BY SASAKI)

TYPICAL BUDGET ALLOWANCE

RELATIVE LEVEL OF MAINTENANCE

Non-Structural Best Management Practices (BMPs) Maintenance/Management BMPs Outdoor Storage of Materials Any materials stored outside should be evaluated for the potential to leach contaminants when in contact with stormwater and covered or stored inside as appropriate. This includes stockpiled landscape waste, soils, machinery and related metal parts. Materials storage for construction activities should be addressed completely in the Stormwater Pollution Prevention Plan for construction activities with greater than 1-acre of soil disturbance.

Figure 5-33

NPDES Construction Permit Compliance

Campus-wide

Updates as necessary.

Campus-wide

Updates as necessary.

Agricultural Landscapes and Ag Heritage Park

Updates as necessary.

Construction Soil Management The University may choose to have a specific soil re-use and stockpiling program for soils excavated during construction projects. Contractors should adhere to the requirements of their contracts with the University in terms of the location for storage and/or reuse of soils removed or brought in for projects. Opportunities for the sale or re-use of surplus should be investigated and practice recommendations made.

Figure 5-34

Livestock Management Livestock waste management in the southern portions of the Campus (around the swine breeding facility, the bull testing facility, poultry management houses, and the Veterinary school) help protect Parkerson Mill Creek. Management of livestock waste helps prevent the runoff of pathogens and nutrients into the Creek and affect the health of the Creek and other surface waters downstream. 83

TMDL Compliance MS4 Permit Compliance

Significant pathogen removal potential TMDL compliance

PMC WMP Action Plan

Figure 5-35

Auburn University Landscape Master Plan, Comprehensive Campus Master Plan Update 2014


PERFORMANCE METRICS1 STORMWATER MANAGEMENT PRACTICE

DESCRIPTION

MANAGEMENT GOALS & COMPLIANCE1

POLLUTANT REMOVAL1

APPLICATION AT AUBURN UNIVERSITY LANDSCAPE TYPES (AS DEFINED BY SASAKI)

TYPICAL BUDGET ALLOWANCE

RELATIVE LEVEL OF MAINTENANCE

Non-Structural Best Management Practices (BMPs) Maintenance/Management BMPs Bridges/Culverts Maintenance Cleaning and Maintenance of Bridge Cross sections and Culverts and maintaining capacity help prevent erosion or build up of debris.

MS4 Permit Compliance

Investigation of discharges other than stormwater to the storm drain system and/or Parkerson Mill Creek and removal of any illicit connections to the storm drain system prevents water quality degradation.

TMDL Compliance

Auburn University Hydrologic/ Hydraulic Study includes survey and documentation of closed pipe drainage system for condition and capacity, as well as watershed wide hydrologic analysis including PMC H/H characteristics. Will be useful tool for future design of stream restoration and on-campus conveyance system requirements in collaboration with campus design goals, water quality goals and conveyance (flood protection) goals

MS4 Permit Compliance

Figure 5-36

Evaluations or Programs Illicit Discharge Detection Program

MS4 Permit Compliance

Significant pathogen removal potential TMDL compliance

Figure 5-35

Hydrologic and Hydraulics Study

Figure 5-38

Post-Construction Stormwater Control Measures

PMC WMP Action Plan

84


Notes and Sources of Information 1. TMDL = Final Total Maximum Daily Load for Parkerson Mill Creek for Pathogens (E. coli). Assessment Unit ID: AL03150110-0202-200. Alabama Department of Environmental Management, September 2011. MS4 = Municipal Separate Storm Sewer System NPDES Discharge Permit. Refers to the six minimum measures and overall stormwater management requirements required by the State Stormwater Permit issued to the University. PMC WMP = Parkerson Mill Creek Watershed Management Plan (Alabama Department of Environmental Management, December 2010.) NPDES: National Pollutant Discharge Elimination System TSS: Total Suspended Solids TP: Total Phosphorus TN: Total Nitrogen

85

2.

Typical Budget Allowance Generally based on; “Stormwater BMP Costs�, Division of Soil & Water Conservation Assistance Program prepared by North Carolina State University, 2007 and general industry information.

3.

Typical Budget Allowance based on ASCE Permeable Pavement Technical Committee Draft Manual 2012 and general industry information

4.

Typical Budget Allowance Based on Parkerson Mill Creek Watershed Management Plan (add more title info) and general industry information

5.

Brown, W., and T. Schueler. 1997. The Economics of Stormwater BMPs in the Mid-Atlantic Region. Prepared for Chesapeake Research Consortium. Edgewater, MD. Center for Watershed Protection. Ellicott City, MD. As referenced in EPA Fact sheet

6.

City of Auburn Water Resources Management Design and Construction Guide, Oct. 2011

Auburn University Landscape Master Plan, Comprehensive Campus Master Plan Update 2014


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.