HydroVisions | Fall 2023

HydroVisions Official Publication of the Groundwater Resources Association

VOLUME THIRTY-THREE DECEMBER 2023

2023 Fall Issue

V.33

HydroVisions

HydroVisions ISSN 2837-5696

HYDROVISIONS is the official publication of the Groundwater Resources Association of California (GRA).

GRA’s mailing address is 808 R Street. Suite 209, Sacramento, CA 95811. Any questions or comments concerning this publication should be directed to the newsletter editor at hydrovisions@grac.org The Groundwater Resources Association of California is dedicated to resource management that protects and improves groundwater supply and quality through education and technical leadership.

EDITOR Rodney Fricke hydrovisions@grac.org EDITORIAL LAYOUT Smith Moore & Associates EXECUTIVE OFFICERS PRESIDENT R.T. Van Valer Roscoe Moss Company Tel: 323-263-4111 VICE PRESIDENT Christy Kennedy Woodard & Curran Tel: 925-627-4122 SECRETARY Erik Cadaret West Yost Tel: 530-756-5905 TREASURER Rodney Fricke GEI Consultants Tel: 916-631-4500 DIVERSITY, EQUITY AND INCLUSION OFFICER Marina Deligiannis Lake County Water Resources Tel: 707-263-2213

DIRECTORS Jena Acos Brownstein Hyatt Farber Schrek Tel: 805-882-1427 Murray Einarson Haley & Aldritch, Inc. Tel: 530-752-1130 Yue Rong Los Angeles Regional Water Quality Control Tel: 213-576-6710 Abhishek Singh INTERA Tel: 217-721-0301 Clayton Sorensen Balance Hydrologics, Inc. Tel: 510-704-1000 x206 John Xiong Haley & Aldritch, Inc. Tel: 530-752-1130 Roohi Toosi APEX Environmental & Water Resources Tel: 949-491-3049 Moises Santillan Water Replenishment District 562-275-4279

IMMEDIATE PAST PRESIDENT Abigail Madrone West Yost Associates Tel: 530-756-5905 ADMINISTRATIVE DIRECTOR Amanda Rae Hall Groundwater Resources Association of California ahall@grac.org To contact any GRA Officer or Director by email, go to www.grac.org/board-of-directors The statements and opinions expressed in GRA’s HydroVisions and other publications are those of the authors and/or contributors, and are not necessarily those of the GRA, its Board of Directors, or its members. Further, GRA makes no claims, promises, or guarantees about the absolute accuracy, completeness, or adequacy of the contents of this publication and expressly disclaims liability for errors and omissions in the contents. No warranty of any kind, implied or expressed, or statutory, is given with respect to the contents of this publication or its references to other resources. Reference in this publication to any specific commercial products, processes, or services, or the use of any trade, firm, or corporation name is for the information and convenience of the public, and does not constitute endorsement, recommendation, or favoring by the GRA, its Board of Directors, or its members.

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HydroVisions

HydroVisions

Official Publication of the Groundwater Resources Association

Contents President's Message

Page 4

Sea Level Rise Guidance

Page 6

Introduction to Subsidience

Page 10

Artificial Intelligence

Page 12

Salty Solutions (Pt. II)

Page 14

California Dust Bowls

Page 16

GeoH2OMysteryPix

Page 18

SGMA Implementation

Page 20

WGC Wrap-Up

Page 24

Parting Shot

Page 26

ISSN 2837-5696

8 California’s Sinking Feeling:

An Introduction to Subsidence

12 Salty Solutions (Part II)

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President’s Message As my term as President comes to a close, I find myself reflecting on the incredible journey we have embarked upon together the past two years. It is with a deep sense of gratitude I extend my heartfelt thanks to each and every one of you for your unwavering support, dedication, and tireless efforts in advancing the goals of our valued organization.

So what have we accomplished in the last 2 years? I would love to take the time to comment on everything we have done, but instead I will highlight a few of my favorites. First, we held ISMAR11 in Long Beach, which was both our largest and first ever international event.

We hosted the largest attended Western Groundwater Congress this year in Burbank with the debut of “GRA Silent Disco”. In Sacramento, our Law and Legislative Symposium was graced with presentations from both the President pro Tempore of the California State Senate, Senator Toni Atkins, as well as California's Natural Resources Secretary Wade Crowfoot and Senator Anthony Portantino. We have recently seen the revitalization of the San Joaquin Valley Branch and have watched many of our other branches flourish with a successful balance of in-person and virtual branch events. GRA has seamlessly worked through administrative changes with the help of our partners at Smith Moore & Associates. Finally, as the former GRA Treasurer, I am pleased to report we have reached the highest cash reserves in the history of GRA – a reflection of the prudence with which we have managed our resources, allowing us to set a solid foundation for future endeavors like scholarships and education sponsorships.

Working alongside such a dynamic, committed, and passionate group of individuals has been nothing short of inspiring. Our Board of Directors, in particular, has exhibited exceptional qualities that have propelled GRA to new heights as you can see.

Qualities like dedication, intelligence, resourcefulness, and hard work have been the pillars on which we’ve built our successes over the past few years. Our ability to have collaborative efforts in building our events have not only fortified GRA’s standing within the groundwater community, but have also positioned us as a beacon of excellence, and have contributed to the broader dialogue on sustainable groundwater management.

As I pass the torch to this next cadre of leaders, I am excited about the wealth of opportunities that lie ahead. I am confident GRA is in exceptionally capable hands with Individuals like Christy Kennedy, Erik Cadaret, Marina Deligiannis, and Moises Santillan who will be in leadership roles and bring a combination of experience, insight, and energy to the table. The pool of leaders within our organization is truly remarkable, and I am optimistic about the innovative and impactful initiatives they will spearhead in the coming years. GRA’s future can be characterized by a sense of optimism, fueled by the collective aspirations of our members and the strategic vision of our leadership. I encourage each of you to continue contributing your expertise and passion to ensure GRA’s continued success.

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I am confident that, under your continued guidance and dedication, GRA will not only sustain its momentum but will reach new heights of excellence.

While having an amazing Board is important, we know the strength of any organization lies in the collective commitment of its members, and I am truly fortunate to have witnessed the dedication so many of you have brought to GRA. Your enthusiasm and commitment have been instrumental in shaping our association and where it is headed. Beyond the organizational milestones, it is the camaraderie and collaboration among our members that make GRA a thriving community. The relationships forged, the knowledge shared, and the bonds created are invaluable. I am grateful for the friendships that have blossomed during my time as President and for the cooperative spirit that defines GRA. In closing, I extend my deepest appreciation to the entire GRA community. Your unwavering commitment has been the driving force behind all of our achievements. The Groundwater Resources Association of California stands as a testament to what can be accomplished when like-minded individuals come together with a shared purpose. As we embrace the future with enthusiasm and optimism, let us continue to uphold the values that define GRA—education, collaboration, and a dedicated commitment to resource management that protects and improves groundwater supply and quality through education and technical leadership.

Thank you for the honor and privilege of serving as your President. I look forward to witnessing the continued success and growth of GRA under the capable leadership of those who follow.

With sincere gratitude,

R.T. Van Valer Outgoing President

Thank you to all of our Annual Sponsors!

Tier Two Sposnors

Roscoe Moss Company

President’s Message

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HydroVis DTSC’s Draft Guidance on Incorporating Sea Level Rise (SLR) into Contaminated Site Cleanup

by Raghavendra Suribhatla, PhD, PE1; Roohi Toosi, PE2; Daniele Spirandelli, PhD1

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1. Haley & Aldrich; 2. APEX Environmental & Water Resources Rsuribhatla@haleyaldrich.com; roohi@apexwater.com; DSpirandelli@haleyaldrich.com

Agency (EPA) and the State of Washington Department of Ecology (WA DoE). We discuss how climate-resilient remediation represents a new paradigm for the remediation industry and will require a collaborative effort between stakeholders, regulators and practitioners to tackle challenges posed by SLR.

Introduction:

SLR Guidance for DTSC Project Managers

California’s coast could face sea-level rise (SLR) of up to 1 foot by 2050 and 3.5 feet by 2100 (OPC, 2022). SLR could create cascading and compounding impacts, including coastal floods, extreme wave action, as well as intensify seawater intrusion. SLR could lead to inundation at contaminated sites, halt remediation operations, and remobilize contaminants.

The California Ocean Protection Council (OPC) is the State’s recognized authority and provides a science-based methodology for state and local governments to analyze and assess the risks associated with sea-level rise, and to incorporate sea-level rise into state decisions. OPC’s Sea Level Rise Action Plan (OPC 2022) states that SLR Adaptation planning should include pathways for resilience to a 3.5foot rise by the year 2050 and a 6.0-foot rise by the year 2100. Following OPC’s SLR Action Plan, the California Department of Toxic Substances Control (DTSC) developed a draft “Sea Level Rise Guidance to DTSC Project Managers for Cleanup Activities” (DTSC 2023). The public comment period will close on October 31, 2023, and DTSC is planning to update the guidance in first quarter of 2024. In this article we highlight key elements of the draft DTSC SLR Guidance and provide an overview of other recent regulatory guidance documents from the United States Environmental Protection

The DTSC guidance aids DTSC project managers in evaluating SLR impacts on contaminated site cleanup. The draft guidance states that SLR Vulnerability Assessment (SLRVA) should be conducted at each stage of the remediation process, including remedial investigation, feasibility study, remedy selection and design, remedial action, operation & maintenance, and monitoring. The process outlined in DTSC’s draft guidance for conducting SLRVAs is based on the decision framework and SLR projections presented in the “State of California Sea Level Rise Guidance 2018 Update” (OPC 2018), further referred to as SLR Guidance 2018. The recent draft SLR guidance adds certain minimum requirements to the SLR Guidance 2018 decision framework with additional considerations for contaminated sites.

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The SLR Guidance 2018 includes projections for 12 active tide gauges in California, based on two emissions (low and high) trajectories. For each tide gauge, probabilistic SLR projections are provided over various timescales for each emissions trajectory, along with an extreme H++ scenario.

SLR values under the ‘Medium-High Risk Aversion’ probability correspond to a 0.5% probability or 1-in-200 chance. The H++ or the ‘Extreme Risk Aversion’ is not a probabilistic projection

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sions and corresponds to an extreme SLR scenario resulting from rapid ice loss from the West Antarctic Ice Sheet. The SLR Guidance 2018 presented a 5-step process for assessing risk due to SLR and developing adaptation plans: 1. Identify the nearest tide gauge.

2. Evaluate project lifespan.

3. Identify range of SLR projections for the nearest tide gauge and project lifespan.

4. Evaluate potential impacts and adaptive capacity across a range of SLR projections and emissions scenarios.

5. Select SLR projections, based on risk tolerances, and develop adaptation pathways that increase resiliency to SLR and include contingency plans if projections are exceeded.

The above steps are slightly modified in the draft DTSC guidance with specific minimums on the project lifespans and the risk tolerances. The project lifespan is required to be the larger of the projected timeframe for remedy completion or 30 years. DTSC will also require SLRVAs to use the higher SLR value based on the Medium-High Risk Aversion SLR or OPC’s targets for adaptation planning (3.5 feet by 2050 and 6.0 feet by 2100). For example, the projected SLR for San Francisco in 2100 is 6.9 ft (medium-high risk aversion). For contaminated sites with ‘water-reactive waste’ or critical infrastructure (highways, bridges, water treatment plants, etc.), the draft guidance required SLRVAs to use the H++ Extreme Risk Aversion SLR projections. However, based on a recent State Agencies SLR Workshop, the H++ scenario is no longer considered plausible. DTSC is expected to provide alternate projections in the updated guidance.

Potential impacts to be evaluated include changes to site hydrogeology, geochemistry, and exposure pathways, thus resulting in a comprehensive re-evaluation of the conceptual site model (CSM) under projected SLR. Most salient of the impacts are remobilization of residual contamination, alteration of groundwater flow and contaminant transport,

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and elevated vapor intrusion potential.

For sites with contamination above closure criteria, DTSC will evaluate remedial actions at least every five years as well as make protective determinations when new information arises. Following SLRVA review, DTSC Project Managers will determine if an adaptation plan is required. The guidance mentions that DTSC will require full action at the remedy implementation stage, although a phased adaptation approach may be considered on a selective basis.

Climate Resilient Remediation Guidance from Other Agencies The WA DoE Toxics Cleanup Program guidance for cleanup project managers (“Sustainable Remediation: Climate Change Resiliency and Green Remediation”) was based on a statewide vulnerability assessment of cleanup sites (WA DoE 2023). The assessment identified SLR as the largest risk to sediment and upland cleanup sites in or near marine and tidally influenced waterbodies followed by flooding, extreme precipitation, wildfire, landslides/erosion, and drought for inland cleanup sites. A GIS tool was developed for DoE staff to conduct site-specific vulnerability assessments using SLR projections and current flood, landslide, and wildfire risk maps. The document provides a step-wise process for performing assessment for a selected site, including a structured approach for identifying potential impacts and risk scenarios for a combination of specific climate hazard and site-type, followed by incorporating impacts in to the CSM and remedial investigation. The guidance includes examples of screening and evaluating remedial alternatives for different site-types and provides specific recommendations for increasing resilience for known vulnerabilities, along with two case studies focused on adaptation to SLR. article continues on next page

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EPA has also provided several resources through its Climate Change Adaptation Resource Center, including region and area-specific risks posed by climate change, relevant adaptation strategies, case studies, and EPA funding opportunities. Finally, the Superfund program prepared three technical fact sheets (EPA, 2021) summarizing remediation technology vulnerabilities to consider for: •

Contaminated sediment remedies (EPA 542-F-19-003);

•

Contaminated waste containment systems (EPA 542-F-19-004); and

•

Groundwater remediation systems (EPA 542-F-19-005).

Tables 2 or 3 in each fact sheet provide examples of potential adaptation measures for remediation system components to address climate change impacts associated with temperature, precipitation, wind, sea level rise, and wildfires.

Conclusion DTSC is addressing potential impacts of SLR on contaminated site cleanup through active engagement with impacted communities and practitioners. Incorporating future SLR projections into CSMs and remediation strategies represents a new paradigm for all stakeholders. Several resources are available for practitioners to incorporate SLR and work with DTSC PMs to implement climate-resilient remediation programs.

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References Department of Toxic Substances Control (DTSC), 2023. Sea Level Rise Guidance to DTSC project managers for cleanup activities, draft for immediate use and public comment, https://dtsc.ca.gov/wp-content/uploads/sites/31/2023/02/ DTSC-SLR-GUIDANCE-February-2023.pdf Ocean Protection Council (OPC), 2018, Sea-Level Rise Guidance 2018 Update, https://www.opc.ca.gov/webmaster/ ftp/pdf/agenda_items/20180314/Item3_Exhibit-A_OPC_ SLR_Guidance-rd3.pdf Ocean Protection Council (OPC), 2022, State Agency SeaLevel Rise Action Plan for California, 2022, Ocean Protection Council (OPC), https://www.opc.ca.gov/webmaster/_media_ library/2022/08/SLR-Action-Plan-2022-508.pdf Sustainable Remediation: Climate Change Resiliency and Green Remediation, 2023, Washington Dept. of Ecology, https://apps.ecology.wa.gov/publications/ SummaryPages/1709052.html United States Environmental Protection Agency, 2021, Consideration of Climate Resilience in the Superfund Cleanup Process for Non- Federal National Priorities List Sites, OLEM Dir. No. 9355.1-120, Memo to Regional Superfund National Program Managers, https://semspub.epa. gov/work/HQ/100002993.pdf 8

2023 Fall Issue

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KƚŚĞƌ ^ĞƌǀŝĐĞƐ

KƚŚĞƌ ƐĞƌǀŝĐĞƐ ŝŶĐůƵĚĞ D͕ Ɛd D͕ Zd͕ ^ĞŝƐŵŝĐ͕ ĂŶĚ ŵŽƌĞ͘ HydroVisions

HydroVisions

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HydroVis California’s Sinking Feeling: An Introduction to Subsidence Tyler Hatch, Wesley Neely, Vivek Bedekar, and Gus Tolley thatch@intera.com, wneely@stanford.edu, vivekb@sspa.com, gtolley@geo-logic.com Land subsidence is a general term for the lowering of land surface elevation due to physical changes in the underlying geologic material. Subsidence can occur naturally or be induced by human activity and is a global concern as it can damage critical infrastructure (e.g., roads, levees, canals, and pipelines) and exacerbate impacts from sea level rise in coastal areas. Causes of land subsidence include: • • • •

Sediment compaction from reductions in pore fluid pressure (e.g., from oil, gas, and groundwater extractions) Oxidation of peat soils Collapse of cavities in rock formations from dissolution or erosion (e.g., sinkholes) Tectonic and volcanic processes

In this series of articles, land subsidence due to sediment compaction resulting from groundwater pumping, particularly in California, will be explored. This first article provides a brief overview of the physical causes of subsidence from sediment compaction.

Subsequent articles in this series will discuss the following topics: • • • •

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Winter 2024 – Subsidence Data: Techniques, Availability, and Interpretation Spring 2024 – Tools and Models: Estimating and Predicting Subsidence Summer 2024 – Pitfalls of Subsidence: Damages Done Fall 2024 – Arrested Displacement: Subsidence Mitigation

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How does groundwater pumping lead to subsidence?

Unconsolidated sediments make up the majority of California’s Central Valley aquifer system, and the arrangement of particles (grains) in the subsurface exists in equilibrium with the surrounding environment. The weight of geologic materials above the aquifer (overburden) at a given location is balanced by a combination of the strength/ orientation of the grains and water pressure within the pore space between the grains (or more generally, pore pressure).

When under pressure, water shares the overburden with loosely packed materials in the subsurface due to its limited compressibility and buoyancy, a property of water that exerts outward thrust to counter the overburden. However, when the pore pressure is reduced by groundwater pumping, a portion of the support for the overburden is transferred from the pore water to the sediments. This weight transfer leads to a reduction in pore space between grains as the counteracting buoyant thrust to keep pores open is lowered. The reduction of pore space is observed at the surface as land subsidence (Figure 1).

If the pressure change is relatively small or recovers quickly, the pore water can retake a portion of the overburden from the sediment grains when the pore pressure returns to its initial value. This subsidence is classified as elastic (or reversible) and is typically on the order of millimeters to centimeters of vertical displacement. In groundwater reliant regions, pressure changes within an aquifer due to groundwater pumping can be large and/or persist for long periods of time (months to decades). In response to supporting more of the overburden, the orientation of grains may rearrange and result in a reduction of pore space.

This subsidence is classified as inelastic (or irreversible/ permanent); and impacts water resources management

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sions

Figure 1 – Diagram of unconsolidated aquifer compaction processes. (Courtesy of US Geological Survey; https://www.usgs.gov/media/images/aquifer-compaction)

because it permanently reduces groundwater storage (less pore space means less storage) and impacts surface water conveyance infrastructure. Further, inelastic land subsidence may reduce the effectiveness of flood control systems by reducing their design capacity and increasing the risk of failure during high water events.

Necessary Conditions. Not all sediments have equal potential to cause land subsidence. In the Central Valley, there is an array of grain sizes, shapes, and materials including gravel, sand, silt, and clay. Clays are often the most susceptible geologic material to inelastic land subsidence as most clay

minerals are relatively thin and flat. Due to their small size, clay particles are deposited in low energy environments, such as lakes or on the margins of flood plains and alluvial fans, and come to rest in random orientations leading to a large percentage of pore space by volume. Clay particles may remain loosely packed despite being buried deep within the subsurface so long as the overburden is supported by sufficient pore pressure. If pore pressure decreases sufficiently, the increase in effective stress (i.e., the difference between stress caused by weight of overburden and counteracting pore pressure) on the clay particles can lead to compaction and loss of available pore space as the grains collapse on each other. article continues on next page

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Time Scales. Subsidence can occur on multiple time scales, depending on the hydrological properties of the sediment (e.g., hydraulic conductivity and specific storage), subsurface structure (e.g., sediment type and distribution), and prior pressure changes experienced (e.g., historical lows in groundwater levels; pre-consolidation stress). For example, in coarser sediments where pumping wells are generally screened, the relatively high vertical hydraulic conductivity of sands and gravels allow for faster equilibration in response to pressure changes. However, if an interbedded clay unit is present, more time is required for the pressure drop to propagate through the clay unit as it has a lower vertical hydraulic conductivity.

The thicker the clay layer, the longer it takes for the pressure to propagate. Consequently, pressure could return to a former (higher) state in the coarser materials, but the clay would not re-pressurize (equilibrate) as quickly. As a result, in interbedded groundwater systems water levels can rebound in coarse-grained aquifers while subsidence may continue to occur for years to decades as the clay continues to equilibrate to a previous pressure drop.

Importance. The story of subsidence in the Central Valley is tied to the development of the Valley itself. In average years, groundwater supplies a third of the water demand while in drought years that value is doubled. During periods of high groundwater use (e.g., 1970s and 2010s), several meters of subsidence have been observed (Figure 2), jeopardizing vital water conveyance systems such as the Friant Kern Canal and the California Aqueduct. So important is subsidence that it is one of the six key sustainability indicators in California’s landmark Sustainable Groundwater Management Act (SGMA).

Forthcoming articles in this subsidence series will focus on the needs to measure (article 2), model (article 3), and manage (articles 4 and 5) land subsidence to attain sustainability goals and protect the health of our water resources.

Figure 2 – Markers of historical land subsidence showing considerable elevation change near Mendota, CA (left) and in Merced County CA (right). (Courtesy of US Geological Survey; https://www.usgs.gov/media/images/location-maximum-land-subsidence-us-levels-1925-and-1977; https://www.usgs.gov/media/images/ land-subsidence-near-el-nido-ca)

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Gain Control of Water Resources

Regulatory Compliance:

A comprehensive approach to water resource management is crucial for ensuring a sustainable and reliable supply of clean water. This involves a multi-faceted strategy that addresses various aspects of water acquisition, treatment, distribution, and monitoring. The Water Resources module aims to provide water utilities with the necessary tools to effectively manage these aspects. Here's a breakdown of the key components and strategies involved:

Adherence to Standards: Ensure compliance with local, regional, and national water quality and safety regulations.

Water Quality Management: Regular Monitoring: Implement a robust water quality monitoring system to continuously assess the chemical, physical, and biological characteristics of the water source.

Adaptive Management: Flexibility: Develop strategies that allow water utilities to adapt to changing conditions, such as varying water availability due to seasonal fluctuations or climate change.

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Network Resilience:

Innovation and Research:

Infrastructure Maintenance: Regularly inspect, maintain, and upgrade the water distribution infrastructure to prevent leaks, breaks, and inefficiencies.

Continuous Improvement: Stay updated with emerging technologies and research in water treatment, distribution, and management to implement innovative solutions.

Data-Driven Decision Making: Data Collection: Gather comprehensive data on water quality, consumption patterns, distribution system performance, and more.

Resource Efficiency: Water Conservation: Promote water conservation measures among consumers, such as efficient water use practices, leak detection, and reuse of treated wastewater.

Stakeholder Engagement: Collaboration: Engage with local communities, government agencies, NGOs, and other stakeholders to ensure a holistic and inclusive approach to water resource management.

By integrating these strategies and components, the Water Resources module can offer water utilities a comprehensive approach to managing water resources effectively, safeguarding water quality, promoting sustainability, and ensuring a reliable supply of clean water to communities.

Venusstraat 17 4105 JH Culemborg The Netherlands +31 (0)345 - 61 44 06 info@realworld-systems.com www.realworld-systems.com

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HydroVis Salty Solutions – Part II

by William E. (Bill) Motzer Introduction In Part I (Spring 2023 HydroVisions), I discussed the relationship of total dissolved solids (TDS) and electrical conductivity (EC), or conductivity, the ability of a substance (i.e., a solution) to conduct an electric current. Specific electrical conductivity is the conductivity of a body of unit length and unit cross section at a specified temperature. EC is widely applied as a basic tool in assessing water quality and often measured when water samples are collected for water quality chemical analyses. EC commonly is measured in micromhos per centimeter (µmhos/cm) or deciSiemens per meter (dS/m) (Driscoll, 1989), whereas TDS is measured in milligrams per liter (mg/L). As we shall see, there is a relationship between the two. EC’s value is that modern instrumentation allows one to easily measure it in the field using a conductivity meter. (Note: originally published in Motzer, 2016).

General Principles of Conductance and EC In metals, an electric current is transmitted by electrons, whereas in solutions it is carried by both cations and anions.

How well a solution conducts electricity depends on several factors, including temperature and ionic valences, mobility, and concentrations. In most aqueous solutions, ionic strength varies from those electrolytes having negligible to very low conductivity (i.e., distilled or deionized water) to the high conductivity of concentrated chemical samples and salty solutions. Therefore, water with few ions is less conductive than solutions with more ions.

Conductance in the laboratory is often measured by applying an electrical current (I) to two electrodes immersed in a solution and measuring the resulting voltage (V). During this process, cations migrate to the negative electrode and anions to the positive electrode; thus the solution acts as an electrical conductor (Figure 1). A solution’s resistance (R) to current flow can be calculated using Ohm’s law which states that the current through a conductor between two points is directly

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proportional to the voltage across the two points. With the constant of proportionality, one arrives at the simple equation that we all memorized in introductory physics and chemistry using Ohm’s law triangle (Figure 2): Therefore: I = V/R; V = I x R, and R = V/I, where I is the current through the conductor measured in amperes, V is the voltage measured across the conductor in volts, and R is the resistance of the conductor in ohms [Ω]. More specifically, Ohm's law states that R in this relationship is a constant, independent of current.

Using R = V/I, we may determine conductance (C) which is defined as the reciprocal of the electrical resistance (R) for a solution occurring between two electrodes. As stated above, it’s measured in Siemens [S] which equals [Ω-1] and is represented as Ʊ and measured in mohs (the reverse of ohms): C = 1/R

A conductivity meter therefore can be used effectively to measure a solution’s conductance and converting and displaying the instrumental reading as conductivity. It does this by using a cell constant (K), which is the ratio of the distance (d) between the electrodes to the area (a) of the electrodes, thus: K = 𝑑/𝑎, where:

K = cell constant in m-1 a = effective area of the electrodes in m2, and d = distance between the electrodes in m However, K is often expressed as cm-1 because the actual cell dimensions are in cm.

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sions Finally, the conductivity reading of a solution or water sample changes with temperatures, and the instrument corrects for this by using conductivity κ in which: κ = C x 𝐾, where:

Groundwater Specialists

C = conductance [S] K = cell constant [m-1 or cm-1] The conductivity κ is now expressed in S/cm, or a more convenient unit such as μS/cm.

However, when calculating TDS from a conductivity measurement, a TDS factor or constant must be applied that is dependent on the type of solids dissolved in water.

Depending on the water source, this constant changes.

Most conductivity meters use a common, approximate constant of 0.65. Fresh or nearly pure water generally has a lower TDS constant of ~0.47 to 0.50. However, when measuring mixed water types or saline water (with a conductivity values >5000 uS/cm), the TDS constant should be higher or ~0.735 to 0.80. Next time, we’ll explore this relationship in more detail.

Reference Driscoll, F.G., 1989, Groundwater and Wells (2nd edition), Johnson Filtration Systems, Inc., St. Paul, MN, 1108 p. (µmohs: p 92-94).

Motzer, W.E., 2016, Salty Solutions: The VORTEX, v.

LXXVII, n.4, pp.6-7. www.calacs.org.

Without The Suit & Tie

Our mission is to provide our clients with exceptional ser vice, our employees with a great work environment, and societ y with lasting value in the work we do.

Over 18 years providing:

• Hydrogeologic Characterization • Exploratory Drilling, Well Drilling & Construction Management • Depth-Specific Groundwater Quality Characterization • Potable & Non-Potable Well Siting & Design • Well Assessments & Rehabilitation • Regulatory Permitting Support • Groundwater Basin Characterizations • Recharge Basin Support

Figure 1: Ohms law triangle.

Figure 2: Simple flow cell diagram showing migration of ions in solution.

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www.woodrodgers.com/careers Sacramento | Roseville | Oakland | Pleasanton O r a n g e | S a n D i e g o | R e n o | L a s Ve g a s 15 2023 Fall Issue

HydroVis California Dust Bowls

by Todd Jarvis (todd.jarvis@oregonstate.edu) The Worst Hard Time: The Untold Story of Those Who Survived the Great American Dust Bowl is an American history book written by former New York Times journalist and Pulitzer Prize winner Timothy Egan. Historians say the American Dust Bowl was the nation's worst prolonged environmental disaster. The largest national migration occurred during the Dust Bowl, with nearly 200,000 folks relocating from the U.S. Midwest to the growing farming communities in the San Joaquin Valley of California.

Damned if Desiccated Are hard times coming again? Global declines in endorheic, or closed, basins are bellwethers of drying times, but not all endorheic basins are dry due to drying times. California's Owens Lake functioned with consistent inputs and water levels until the Owens River was diverted into the Los Angeles Aqueduct by Los Angeles Department of Water & Power (DWP) causing Owens Lake to desiccate by 1926.

and Rio Tinto Kennecott donated water rights to slow the drying. Utah State University is training "water shepherds" to ensure water donated to the Great Salt Lake actually makes it to the Great Salt Lake without pirating.

Saline Lakes Act In a surprising bipartisan effort Senators Merkley [D-OR], Rosen [D-NV],. Romney [R-UT], Cortez Masto [D-NV], Wyden [D-OR], and Feinstein [D-CA] championed the Saline Lake Ecosystems in the Great Basin States Program Act of 2022 (Saline Lakes Act), providing $25 million to the US Geological Survey (USGS) over the next five years to study lakes in the Great Basin. Most of the closed basins in California are included in the Saline Lakes Act.

Some of the mysteries and mythology of Great Basin groundwater are exemplified by lakes in closed basins. DWP began diverting water from Mono Lake’s tributary streams in the early 1940s, sending water 350 miles south to Los Angeles.

Since the diversion, Mono Lake’s water level has dropped by 45 feet and doubled in salinity. The magnificent tufa spires found at Mono Lake and tufa mounds at Oregon's Lake Abert reflect the intricate geochemical dance between discharging groundwater and surface water in closed basins.

The disappearance of the Great Salt Lake over the past few years due to drying times and diversions lead to the Great Salt Lake Strike Team, a collaboration between the University of Utah and Utah State University. Brigham Young University developed emergency measures calling for dramatic reductions in surface water diversions to slow the decline in water level. The Church of Jesus Christ of Latter Day Saints 16

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sions While the $25 million set aside is welcomed by the Great Basin states to "assess, monitor and conserve" saline lake ecosystems in the Great Basin, Brigham Young University and the Friends of Great Salt Lake are calling for immediate action, not just further study. The USGS Saline Lakes Ecosystems Integrated Water Availability Assessment (Saline Lakes Project) was established in 2022 and "is using an integrated scientific approach to monitor and assess water availability, migratory birds, and other wildlife dependent on saline lakes." The USGS has an annual budget of $5 million for the next few years, and the spending plan is under development. However, comparable projects underway in Oregon at Lake Abert and elsewhere within the Chewaucan Basin recognize the role of groundwater is poorly understood and the perspectives on whether groundwater should be part of collaborative discussions are far from settled.

The work ahead for the USGS will be challenging to say the least. Geologic complexity is an understatement in this region; mountain ranges such as the Confusion Range near the Sevier Lake in western Utah are named after the complex folding and related topography. The structural geologic term "chaos" was coined in the Death Valley region just east of Owens Lake in California. Water budgeting in the region typically provides only an order of magnitude estimate because of fault-bounded basins, fractured-rock and conduit-flow permeability architecture, and the limitations of collecting and interpreting surface water data over large geographic areas. Interbasin groundwater flow can occur naturally or be induced by pumping from wells in different hydrologic basins.

Much of the work of unraveling the mysteries in closed basin hydrogeology involves tracing groundwater with sophisticated methods such as isotope geochemistry and remote sensing using GRACE satellite data.

New Dust Bowl Drying lakes pose an ominous threat to public health and safety in the form of dust. The dry lakebed of California's Owens Lake is the largest single source of dust pollution in the United States. DWP rate payers have spent more than $2 billion on projects to reduce dust emissions by nearly

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100% from Owens Lake, including evaluating pumping groundwater. Dust from the drying Great Salt Lake poses a threat to the well-being of the nearly four million residents living along the Wasatch Front, as well as the multi-billion dollar ski industry as dust is causing the "greatest snow on earth" to melt two weeks early. Milky rain that coated cars in Portland, Oregon was found to be derived from Summer Lake located 480 miles distant. Further afield, the response to SGMA to pumping groundwater in the San Joaquin basin of California may require retiring 500,000 acres of cultivated land leading to an increase in dust.

Likewise, the drying Salton Sea is receiving $250 million from the federal government to supplement California's $583 million investment that includes dust suppression by creating wetlands and ponds fed by springs.

Damned if Drenched Record snowpack in the western United States spanning the Wasatch Mountains in Utah to the Sierra Nevada in California has temporarily slowed the great drying. Lake Tulare has returned once again in the San Joaquin Valley due in part to the subsidence associated with pumping, resulting in what has been referred to as an "Elaborate Tragedy of the Commons".

Mono Lake is expected to rise by 5.5 feet by the fall of 2023.

Likewise, the Great Salt Lake has risen five feet, but the rise in water levels is only expected to last a couple of years. The return of Owens Lake is not as welcomed as elsewhere across the Great Basin with the snow pack runoff damaging both the aqueduct and the billion dollar dust control measures.

An Even "Worst" Hard Time?

According to Timothy Egan, the severe erosion from abandoning soil conservation practices during low crop prices exacerbating the American Dust Bowl was stitched back together through a combination of groundwater derived from the Ogallala Aquifer and integrating the concepts of public entrepreneurship of common pool resources for soil conservation. Will slowing the wasteful haste of surface water diversions and groundwater pumping through SGMA save California and the Great Basin states from the new era of dust bowls, or will the saga become an even “worst” hard time?

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HydroVis GeoH2OMysteryPix

by Chris Bonds, Sacramento Branch Member at Large

GeoH2OMysteryPix is a fun addition to HydroVisions that started in Fall 2022. The idea is simple; I share some questions, some cool supporting geology and/or water resources photo(s) along with a hint, and readers email in their guesses.

In a future issue of HydroVisions, I will share the answer(s) along with some brief background/historical information about the photos and acknowledge the first person(s) to email me the correct answer(s).

GRA looks forward to your enthusiastic participation in GeoH2OMysteryPix.

SUMMER 2023 ANSWERS What is this? Where is it Located?

Hint: You might call this one an over-achieving firecracker!

Congratulations to GRA member Dan Gamon from the RWQCB, Central Valley Region for providing the following correct responses to the Summer 2023 GeoH2OMysteryPix questions: “I think I know this one as a former Hanford Nuclear Reservation Worker…

1) A nuclear device being prepared for underground detonation.

2) The detonation at the Nevada Test Site!”

Background/History: The above photos are relics of Project Sedan; part of the largely forgotten history of the Plowshare Program. The left-side photo shows a patriotically painted nuclear explosive device and associated test cables being carefully lowered into position inside a vertical emplacement shaft in preparation of the underground test for Project Sedan at the Nevada Test Site (NTS).

The right-side photo shows the surface expression and dust cloud from detonation of the Project Sedan nuclear explosive at 1000 A.M. on July 6, 1962.

In 1958, the United States Atomic Energy Commission established the Plowshare Program under the technical direction of Lawrence Radiation Laboratory as a research and development activity to explore the feasibility of using 18

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nuclear explosives for civil, industrial, and scientific purposes.

The reasoning was that the relatively inexpensive energy available from nuclear explosions could prove useful for a wide variety of peaceful purposes. Plowshare’s main applications fell into two broad categories: Large-scale excavation and quarrying (geographic engineering), and underground engineering. In response to a journalist’s request for a definition of geographic engineering, Edward Teller, Father of the Hydrogen Bomb and Plowshare technical director, quipped, “If your mountain is not in the right place, drop us a card.”

Project Sedan was the second underground nuclear test of the Plowshare Program, and its main purpose was to evaluate the feasibility and effects of large-scale nuclear excavation in desert alluvium. The Sedan device was lowered into place 635 feet below the ground surface inside a 36-inch diameter, steel emplacement casing and packed with alternating layers of backfill and sealing materials. The nuclear device was 17 feet long, 38 inches in diameter, and weighed 468 pounds. It took a small crew less than a week to build, working under high

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sions security, in a lightning-resistant building, using parts from all over the U.S. The Sedan thermonuclear explosive device had a yield of 104 kilotons via a 70% fusion and 30% fission reaction. In a matter of seconds, the explosion gouged out 12 million tons of earth and formed a crater 1,280 feet in diameter, 320 feet deep, with an apparent volume of about 6.5 million cubic yards or 4,000 acre-feet. The Sedan explosion released energy equivalent to a 4.75 magnitude earthquake and created the largest explosion crater in the

U.S. which can be seen from space. In 1994, the Sedan Crater was entered into the National Register of Historic Places and is one of the most popular stops on the tour of the former NTS. The Sedan Crater is visited by more than 10,000 tourists a year during monthly NTS tours that are free of charge but book out many months and sometimes years in advance. I highly recommend a tour of the former NTS and Sedan Crater if you are interested in nuclear energy and testing, Cold War history, and are in the Las Vegas area.

Good Reads: Teller, et. al., 1968, Constructive Uses of Nuclear Explosives O’Neill, 1994, The Firecracker Boys Kirsch, 2005, Proving Grounds Kaufman, 2013, Project Plowshare

Fall 2023 Questions What is this? Where is it Located?

Hint: Quite possibly, the most impressive 19th Century roadcut in the United States!

Think you know What this is and Where it is Located? Email your guesses to Chris Bonds at goldbondwater@gmail.com

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HydroVis SGMA Implementation:

the story of conflict, collaboration and lessons learned to reach groundwater sustainability.

A short report out from the GRA/ACWA SGMA Implementation Summit and Workshop, held June 7 and 8 in Sacramento

by Lisa Porta and Adam Hutchinson

This year, the newly revamped SGMA Implementation Summit provided a time to reflect, openly and honestly share stories of successes and challenges, empathize, and lift each other up to brave the next decades of what will be challenging groundwater management conditions. The GRA and ACWA collaboration, with Trevor Joseph and Soren Nelson, allowed for expanded attendance by groundwater managers and agency board members, and a mixing of technical experts and policy-makers.

Panelists provided insights on their “secret sauce” to make progress on the road to sustainability – namely, engage people early in the implementation process, listen to stakeholders, educate and inform, build trust and strong relationships, coordinate and partner with local communities. Sometimes the forced partnerships that were created through the local governance process required by SGMA has resulted in “dysfunctional GSA families”. And with any family, differences in approach and opinions can produce passionate interactions but, hopefully, lead to better outcomes in the end, although time and patience are needed for everyone to get on board. One GSA has had success in overcoming difficult hurdles by organizing a Coffee Shop Committee for a conversation in a casual setting.

With SGMA, it is also important to realize that we all need to come to the same understanding in our basins and that all aspects of SGMA and water management are interconnected. The interpretation of information can only be as good as the data shared; in other words, more sharing of data and information can go a long way in furthering the understanding and problem solving of the issues at hand. SGMA fluency or “SGMAntics” (as coined by Dave Ceppos) helps you use the same language with others in the basin; you may need a SGMA translator at the beginning of the process, but hopefully, SGMA fluency is ramping up.

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sions We are at a turning point in SGMA implementation: time for action and clear collaboration!

INNOVATION is driven by: 1.

2.

3.

4.

Having a problem to solve Having limited resources Having a “no-fail” culture Having a crazy idea

These conditions can perhaps be applied to SGMA implementation, echoing the panelists words of wisdom on the need for creative solutions.

Existing and potential conflicts in SGMA implementation are real, and attendees explored the potential hurdles and how to overcome them. According to attendees, the top conflicts in SGMA are shown below:

Panelists shared how they felt about SGMA and what words came to mind to describe the process: •

Optimistic

•

Inspired

•

Innovative

•

Iterative

•

Excited

•

Creative

Advice for SGMA stakeholder meetings and workshops: Be sure you all speak the same language or at least have a translator in the room who is SGMA fluent and can speak to SGMAntics!

The other question that comes up more and more now is “to adjudicate or not to adjudicate” – in any case, the first question is “who do you invite to the party to dance”? And make sure you teach them the basic steps first before you pursue the entire choreography. Don’t go too fast, consider taking a step back to regroup, as necessary. Finally, be clear about expectations and assumptions before going too far down the road.

While GSAs have been seen by some as “forced marriages”, basin adjudications can be seen as “forced divorces” where more often than not, everyone loses a bit. Orange County Water District explained that by collaborating, rather than adjudicating, the basin yield has more than doubled by aggressively pursuing managed aquifer recharge and water recycling. Hopefully, following the SGMA process will bring about better outcomes for all communities.

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Other potential conflicts were identified and include: • • • • • • •

Barriers to effective communication Clearly identifying roles and responsibilities Stalling (non-decision making) Different interpretations of the regulations Multi-interest approaches Complexity of the local situations Varying perspectives on issues and intended outcomes

On the second-day workshop, international conflict resolution expert Léna Salamé led participants through The Water Message Game role play. The role play was eye-opening to many and showed us that effective negotiation skills, understanding the other side’s concerns, and knowing the rules of the game are necessary to come to a win-win solution for all.

In the meantime, Stay Calm and SGMA On! Lisa & Adam GRA co-chairs of the 2023 SGMA Implementation Summit

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Environmental engineering and consulting.

Providing innovative water quality solutions throughout California for over 40 years.

WATER RESOURCES ENGINEERING SERVICES INCLUDE Groundwater • Wastewater • Stormwater • Watershed Management • Agricultural Water Quality Management

Davis 530.753.6400 Berkeley, San Diego, Santa Monica, Seattle, Ventura

www.lwa.com 22

2023 Fall Issue

Infrastructure Design: Canals and Pipelines Control Structures Pump Stations Wells Facility Rehabilitation Groundwater Recharge & Banking Studies and Modeling: System Master Planning Water Conveyance Water Budgets Subsidence Water Quality

www.provostandpritchard.com

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by By Roohi Toosi, Meeta Pannu, Dan Bryant, Rob Wilhelm, Heather Gosack, Abhishek Singh, Jim Strandberg

Regulatory efforts for enforcing assessment and cleanup on PFAS-impacted sites peaked recently when, on March 14, 2023, the United States Environmental Protection Agency (USEPA) proposed draft National Primary Drinking Water Regulation (NPDWR) standards or maximum contaminant levels (MCLs) for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) at 4 nanograms per liter (ng/L, or parts per trillion) for both. The MCLs are based on non-enforceable MCL goals (MCLg) for PFOA and PFOS of zero, indicating no concentration in drinking water is considered safe in terms of known or expected health risks (Read More on MCLg). In addition to health risks, the MCL also considers practical, economical, and technological limitations such that the MCL is higher than the MCLg. The USEPA also introduced the Hazard Index (HI) for four other common PFAS as the regulatory limit. The HI must be below 1 to be compliant with the regulation. The public comment period for this proposed ruling ended on May 30, 2023, and USEPA plans to finalize the rule by 2024 (Federal Register Document). This article describes the HI and how it is calculated, along with a brief discussion on implications of these proposed MCLs and HI on public water systems and permitting groundwater discharges through National Pollutant Discharge Elimination System (NPDES).

Let’s close the resiliency gap

Hazard Index Calculation We are collaborating with our clients to address the increasingly complex issues related to flood and drought in California.

Together, we can co-create more resilient groundwater and surface water resources.

YOU WAITING FOR? Whether you were born in the 90’s or fondly remember your Doc Martens, we want you!

YOU ARE LOOKING FOR A CHALLENGE YOU WANT TO MAKE A DIFFERENCE YOU WANT AN ENVIROMENT THAT ENCOURGAGES GROWTH

ADD YOUR YOU TO OUR WE WE ARE WEST YOST Use the QR code to apply for open positions

The West Yost crew celebrating the 30th Anniversary of GRA like it’s 1992!

Visit ramboll.com/lets-close-the-gap

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The 6th Annual Western Groundwater Congress Wrap-Up The Future of Groundwater is YOU

Almost two months following the closing of the 6th Annual Western Groundwater Congress (WGC) and I am still beaming. YOU all showed up in full force ready to discuss the difficult issues that we face as a groundwater community. When the WGC planning team and I were formulating the idea behind this conference - The Future of Groundwater is YOU - we wanted to create a shared space where ALL were encouraged to participate with the difficult yet important conversations related to groundwater sustainability in California and the Western United States.

We aimed to ensure that everyone had a seat at the table. I hope with all my heart that we accomplished that. I was completely serious in my opening remarks that this really was a conference focused on what YOU can do to support the groundwater community and based on the initial feedback we received, it sounds like we accomplished it!

The 6th Annual WGC represented a lot of firsts for the Groundwater Resources Association of California (GRA): • We rolled out a DE&I sponsorship opportunity allowing for increased participation.

• We held a brand new “How to Make the Most of Your GRA Membership” Forum where attendees could learn how to become more involved in GRA. • We introduced the “Flow Focused Forum,” where attendees could express their challenges within the groundwater industry.

• We held the first ever WGC Silent Disco, which turned into a 3+ hour dance party (and I am forever known henceforth as ‘Disco Daddy’ haha).

• We heard from groundwater users through our opening panel and what challenges they faced.

• We expressed our challenges and concerns directly to regulators during the closing panel.

• We heard from the most diverse group of speakers and panelists at any WGC to date.

• And last, but certainly not least, we experienced the most attended WGC to date!

This event could not have been a success without all your support - the GRA community and beyond. So before I sign off, I would like to take a moment to thank each of the attendees, sponsors, speakers, moderators, and all the volunteers that made this happen. THANK YOU.

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Some FUN facts from the Congress: • 303 Attendees • 69 sponsors and exhibitors • 3.5 hours of [somewhat silent] dancing • A total estimate here, but likely over 1,000 cups of coffee consumed • 2 talks and a workshop about AI • 9 panels/workshops • 84 platform presentations • Over 30 poster presentations • 6 DEI sponsors • Over 10 student (SNAPP) Presentations • And the most important metric… YOU! We hope you enjoyed the 6th Annual WGC and we hope to see you next year in beautiful Lake Tahoe!

Sincerely,

______________________ Clay Sorensen GRA Director and 6th Annual WGC Chair

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HydroVis Parting Shot

by John Karachewski, PhD

Entrenched meander in the lower Owens River Gorge with the White Mountains in the background. This steep 18-mile-long canyon is located near the eastern edge of the Sierra Nevada in southern Mono County and northern Inyo County. The Owens River eroded through the Bishop Tuff to form the Owens River Gorge.

The Bishop Tuff is the pyroclastic product of approximately 150 cubic miles of rhyolitic magma that erupted explosively during the collapse of Long Valley Caldera about 767,000 years ago. Pleistocene Long Valley Lake occupied the east half of the caldera for almost 600,000 years before overflowing and eroding the modern Owens River Gorge approximately 150,000 years ago.

The meanders in the Owens River Gorge (approximately 400-feet deep) provide evidence for entrenchment of a formerly low-relief stream in response to southward tilting and steepening of the Volcanic Tableland (a south-sloping ignimbrite plateau downgradient of the Long Valley Caldera). In addition to the arid climate and the weak drainage pattern elsewhere on the ignimbrite surface, the meandering course of the gorge suggests incision by overflow of a Pleistocene caldera lake rather than an origin by headward erosion.

Recreational opportunities on Los Angeles Department of Water and Power (LADWP) land in Owens River Gorge include fishing, hiking, and rock climbing. Due to the above average snowpack last winter and spring, LADWP closed the Owens River Gorge to public access for 3 weeks in June 2023, to release higher-than-normal volumes of snowmelt. In cooperation with the California Department of Fish and Wildlife and Mono County, the required 3-week flow helped improve fishery and riparian habitat between the Upper Gorge Power Plant and Pleasant Valley Reservoir.

Photographed on September 10, 2023, at a location with coordinates of 37.480839°and -118.560608°. This photo was taken at Stop 17 of the U.S. Geological Survey (2017) Geologic Field-Trip Guide to Long Valley Caldera, California published as Scientific Investigations Report 2017–5022–L. https://doi.org/10.3133/sir20175120L

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Thank You To Our Contributors Adam Hutchinson, PG, CHg, is the Recharge Planning Manager for the Orange County Water District in southern California. He has over 30 years water resources experience. In his 23 years at the District, he has worked as Director of Recharge Operations and as Senior Hydrogeologist. He has an undergraduate degree in Geology, a master’s degree in Hydrology from the University of Arizona.

Chris Bonds is a Senior Engineering Geologist (Specialist) with the California Department of Water Resources (DWR) in Sacramento. Since 2001, he has been involved in a variety of statewide projects including groundwater exploration, management, monitoring, modeling, policy, research, and water transfers. He has over 30 years of professional work experience in the private and public sectors in California, Hawaii, and Alaska and is a Professional Geologist and Certified Hydrogeologist.

Chris received two Geology degrees from California State Universities.

He has been a member of GRAC since 2010, a Sacramento Branch Officer since 2017, and has presented at numerous GRAC events since 2004.

Daniele Spirandelli, PhD is a Senior Climate Resilience Specialist with Haley & Aldrich. She is a strategic, systems-oriented resilience planner who enjoys working with a diverse range of clients and stakeholders to address their concerns about climate change.

Gus Tolley received a B.S. in geology from UC Santa Barbara, a M.S. in hydrology from New Mexico Tech, and a Ph.D. in hydrology from UC Davis. He has been with Daniel B. Stephens & Associates for six years and works out of the Grass Valley Geo-Logic Associates office specializing in groundwater hydrology, numerical modeling, groundwater-surface-water interactions, and database management systems.

John Karachewski, PhD, retired recently from the California-EPA in Berkeley after serving as geologist for many years in the Geological Support Branch of the Permitting & Corrective Action Division for Hazardous Waste Management. John has conducted geology and environmental projects from Colorado to Alaska to Midway Island and throughout California. He leads numerous geology field trips for the Field Institute and also enjoys teaching at Diablo Valley College. John enjoys photographing landscapes during the magic light of sunrise and sunset. Since 2009, John has written quarterly photo essays for Hydrovisions.

Lisa Porta, PE, is a senior water resources engineer and California Water Strategy Lead with Montgomery & Associates, in Sacramento, CA. She has more than 15 years of groundwater modeling and integrated water resources planning experience in California and the Western United States. She specializes in SGMA implementation and supports local water agencies with navigating the increasingly complex regulatory environment with using appropriate data and tools.

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Raghavendra Suribhatla, PhD, PE is a Technical Expert with Haley & Aldrich. He serves as the California modeling manager for H&A’s applied research and climate resiliency projects.

Roohi Toosi, PE | President & Principal Engineer at APEX Environmental & Water Resources Mr. Roohi Toosi, PE is a Board Director and a member of several committees at GRA. Over the course of his career, Mr. Toosi has conducted and managed projects for utilities, school districts, municipalities, military bases, private developers, contractors, farmers, water districts, and large consulting firms.

Todd Jarvis, PhD, is the Director of the Institute for Water and Watersheds, Oregon State University, Corvallis. Todd has 30 years of experience as a hydrogeologist specializing in groundwater development and source water protection with emphasis in fractured rock and karst terranes. With professional licenses as a Certified Engineering Geologist, Certified Water Right Examiner, and Certified Mediator, his interests include transboundary aquifers, environmental conflict resolution, and education in water science and policy.

Tyler Hatch is a Principal Engineer with INTERA. In his previous role, he was part of the Sustainable Groundwater Management Office (SGMO) at the California Department of Water Resources for almost six and a half years. For the last three years, he was a member of the SGMO management team and led the Modeling and Tools Support Section for the last 3 years. One of the major projects Tyler led was the development of the Fine-Grid California Central Valley Groundwater-Surface Water Simulation model (C2VSimFG), which included improvements to simulating land subsidence in the Central Valley.

Vivek Bedekar is a water resource and environmental consultant with Papadopulos and Associates. He develops numerical codes and model applications to address issues related to water availability and quality.

Dr. Wesley Neely is a Postdoctoral Researcher at Stanford University specializing in the use of land surface displacements for characterizing groundwater dynamics in California’s San Joaquin Valley.

William E. (Bill) Motzer, PhD, PG, CHg, CPG is a somewhat semiretired forensic geochemist. Formerly with Todd Groundwater, he has more than 40 years of experience as a Professional Geologist and more than 35 years of experience in conducting surface, subsurface, and environmental forensic geochemical investigations. His particular expertise is in stable and other isotopic “fingerprinting” and age dating techniques and water quality/contaminant source identification geochemistry.

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Official Publication of the Groundwater Resources Association

Thank you to our Annual Sponsors!

Tier Two

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