HydroVisions | Spring 2022

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2022 Spring Issue th ANNIVERSARY


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 editor@grac.org or faxed to (916) 231-2141. 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 editor@grac.org

EXECUTIVE OFFICERS PRESIDENT R.T. Van Valer Roscoe Moss Company Tel: 323-263-4111 VICE PRESIDENT/SECRETARY Christy Kennedy Woodard & Curran Tel: 925-627-4122 TREASURER Rodney Fricke GEI Consultants Tel: 916-631-4500 DIVERSITY, EQUITY AND INCLUSION OFFICER Lyndsey Bloxom The Water Research Foundation Tel: 571-384-2106 IMMEDIATE PAST PRESIDENT Abigail Madrone West Yost Associates Tel: 530-756-5905 ADMINISTRATIVE DIRECTOR Sarah Erck Groundwater Resources Association of California Tel: 916-446-3626


Jena Acos Brownstein Hyatt Farber Schrek Tel: 805-882-1427 Erik Cadaret West Yose Associates Tel: 530-756-5905 Marina Delgiannis Lake County Water Resources Tel: 707-263-2213 Murray Einarson Haley & Aldritch, Inc. Tel: 530-752-1130 Todd Jarvis Institute for Water & Watersheds, Oregon State University Tel: 541-737-4032 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 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 th commercial products, processes, or services, or the use of any ANNIVERSARY 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.

2022 Spring Issue

V.31 2

2022 Spring Issue


President’s Note

Wells and Words

Page 4

Page 6

Call for Nomination

Page 13


Diversity, Equity, and Inclusion

Drought Conditions

Page 9

Page 10

Key Technical Aspects of DWR Reviews

PFAS Fate and Transport Processes

The Geochemist’s Gallery

ISMAR Is Nearly Here!

Parting Shot

Page 24

Page 26

Page 14

Page 18

Page 22

President’s Note


still remember my first GRA board meeting. It was Saturday, February 13, 2011, in the Nossaman LLP conference room, overlooking our beautiful state capitol building and I was terrified. My father, now a GRA Emeritus Director, wanted me to learn about business by assisting him with the GRA finances as Bookkeeper, while he took on the role of Treasurer. He informed me I would be working with some of the most dedicated and brightest volunteers in California groundwater. As I had just entered the groundwater field 6 months earlier, I was intimidated to sit in the same board room with GRA founders like Vicki Kretsinger, Brian Lewis, and Tim Parker, but quickly found they were so nice and willing to help me learn about the organization they formed in 1992. Continuing to get more involved, I learned so much about groundwater and leadership, as well as built great friendships with so many GRA members. While it has been fun the past few weeks taking a trip down memory lane, I understand GRA is about the future.

GRA has grown a lot since its inception 30 years ago, but one thing that has not changed is we have always strived to be at the forefront of the groundwater world. As I look at our present group of exceptional leaders, I continue to see individuals dedicated to resource management that protects and improves groundwater supply and quality through education and technical leadership. All of these members are striving to make this organization stronger than ever. In 2017, we were excited our first Western Groundwater Congress (WGC) would help connect us with our neighboring western states. Now five years later, GRA will be welcoming people from all over the world at the 11th International Symposium on Managed Aquifer Recharge. The extraordinary experience will kick off a stream of exceptional events, including the Law and Legislation Forum, the GSA Summit and Groundwater 101 Week. Sprinkled between those events will be our GRACast series and then GRA will end the year with an impressive 5th annual WGC, themed “Built for Change.”


R.T. Van Valer has worked for Roscoe Moss Company, a leading manufacturer of water well casing, screen and water transmission pipe, since 2001. R.T. currently serves as the Product Manager and Director of Human Resources for the company. In his 11th year with GRA, R.T. has previously served in multiple executive offices, chaired committees and twice chaired the Western Groundwater Congress.

With events like these, this outstanding organization has sufficiently educated me and given me the courage to not only be able to chair the very first Western Groundwater Congress, but to now lead GRA into this next stage of crucial development. Of course, a lot of that assurance comes from having a remarkable team of executive leaders, members, committee chairs and branch executives to work alongside over the coming years. Our four newest board members have already begun taking on huge responsibilities. We are so excited to have Clayton Sorensen, Marina Deligiannas, Abhishek Singh, and Yue Rong join our board in 2022. It is truly an honor and a privilege to lead GRA into its 30th anniversary and beyond. I look forward to reconnecting with many of my old groundwater friends, as well as meeting new members along the way. HV Best regards,

R.T. Van Valer



Wells and Words

Groundwater pumping impacts: Part 2–Land Subsidence by David W. Abbott, P.G., C.Hg. Consulting Geologi


and Subsidence1 means the lowering of a natural land surface in response to: (a) local earth movements (i.e., mass wasting, creep, landslides, etc.); (b) lowering of fluid pressure (i.e., groundwater and oil/ gas exploitation); (c) removal of underlying supporting materials by mining or solution of solids, either artificially or from natural causes; (d) compaction caused by wetting (hydrocompaction); (e) oxidation of organic matter in soils; (f) added load on the land surface (infrastructure including reservoirs); (g) regional tectonic activity; or (h) lithification. This article will focus on Land Subsidence that is caused by excessive use of groundwater and application of water to certain soils.

Todd2 describes briefly four recognized groups of Land Subsidence that involve groundwater: (1) lowering of the potentiometric (less preferred term piezometric3) surface by mining groundwater in water table and artesian aquifers, especially in thick and inter-bedded confined aquifer systems [San Joaquin Valley – Figure 14 and Santa Clara Valley5]; (2) hydrocompaction6 is the reduction in volume of a low-density sedimentary deposit in response to the application of water - susceptible deposits include loess and alluvial fans derived from fine-grained source materials [west side of the San Joaquin Valley along the CA7 Aqueduct corridor]; (3) dewatering of organic soils which

Figure 1

lowers the water table [SacramentoSan Joaquin Delta]; and (4) sinkhole formation where soluble rocks (i.e., limestone, gypsum, evaporites, etc.) are slowly dissolved by groundwater [many parts of Florida and the southeast US]. Sinkhole formation is relatively uncommon in CA but has occurred recently due to subsurface water conveyance systems that leak (or break) and result in tunnel erosion (a.k.a. piping8) of surrounding sediments and ultimate ground surface failure [Northern CA9 and Los Angeles10]. Land Subsidence has occurred throughout the world, most notably in Venice, Italy; Mexico City, Mexico; and the Netherlands. USGS and Todd11 report that nearly 80% of Land Subsidence identified in the US results from groundwater mining. 6

Mining groundwater from an aquifer (especially artesian) combined with exporting too much water from the watershed that contributes to the recharge of the groundwater basin can result in Land Subsidence that can have significant and very serious negative impacts to ground surface elevations, aquifers, and water supply wells. These permanent surface elevation changes can create major and costly impacts to infrastructure including roads, pipelines, aqueducts, buildings, foundation piers, water supply wells, etc. Physical barriers (i.e., levees) can be constructed to protect low-lying areas (near or below sea level) from flooding and complete devastation from encroaching waters, especially coastal properties [Alviso, CA, Sacramento-San Joaquin Delta, and much of the Netherlands]. Over-pumping near Alviso (Figure 212) caused about 15 feet of Land Subsidence between 1930 and 1960. Sea level rises due to climate change will only exacerbate these problems. Note that levees and other structures may prevent flooding along coastal areas, but a system of pumping plants must also be engineered and maintained to lift water over the levees in order to remove rainwater (and other waters) from low-lying areas and the levees must be periodically inspected to assess their integrity and repaired accordingly.

from both overlying and underlying aquitard units. An aquitard1 is a confining bed or rock formation that retards the movement of groundwater to or from adjacent beds; aquitards do not prevent the flow of water and may serve to store groundwater, although they are not effective as sources of water to wells. An aquiclude3 is a saturated geologic unit that is incapable of transmitting significant quantities of water under ordinary hydraulic gradients. Over-pumping an aquifer increases the vertical hydraulic gradient across the aquitard layers, which can cause dewatering of the aquitards and a lesser hydraulic pressure to support the sediment matrix. When this condition happens, the structural framework of the aquitards become thinner due to compaction which results in the lowering of the ground surface elevation. This inelastic Land Subsidence is permanent and cannot be corrected. Environmental impacts become more serious when the Land Subsidence occurs near sea level. Groundwater pumping should be managed so that overdraft does not occur, and Land Subsidence can be avoided entirely.

Significant Land Subsidence occurs usually over timeframes of decades and might not be readily perceptible to local property owners or well operators.

Figure 2

Land Subsidence is caused by changes to the geotechnical properties (and the soil mechanics) of subsurface sediments (or strata) with the release of groundwater due to overdraft (i.e., over-pumping) of an aquifer. Over-pumping of an aquifer system with aquitards (silts and clays) and/or aquicludes (clays or rock) allows water to slowly drain 7

Significant Land Subsidence occurs usually over timeframes of decades and might not be readily perceptible to local property owners or well operators. Maximum Land Subsidence may occur decades after groundwater pumping has stopped; and can occur over large areas (50 to 4,500 square miles). Note that very local Land Subsidence can also occur around poorly constructed and developed water supply wells by pumping groundwater that is turbid/ silty over a long period of time13 or by pumping sand. This conditions indicates a flaw in the well design, well damage, or the well is over-pumped. Note that centrifugal sand samplers8 (separators) located at the wellhead should not be used for sand control prior to final distribution of groundwater to customers. Sand/silt that is removed with an operational supply well will breakdown the structural fabric of the aquifer around the well which can result in local Land Subsidence at the well location. Figure 1 – Land Subsidence in the San Joaquin Valley, CA. Pictured is Joseph F. Poland, Ph.D., a major scientific contributor to the understanding of Land Subsidence. Location is about 10 miles southwest of Mendota, CA (photo from Bertoldi, Gilbert L. et al., 1991). Figure 2 – In 1914, the Alviso Yacht Club is near sea level; in 1978, the Alviso Yacht Club is about 10 feet below sea level; and a Levee was constructed to prevent flooding of the Town of Alviso, CA (Galloway et al., 1999).

Land Subsidence can be prevented with dynamic, proactive, and proper groundwater management. The groundwater basin and/or aquifer should not be pumped greater than the perennial yield. The perennial yield2 of a groundwater basin defines the rate at which water can be withdrawn annually under specified operating conditions without producing an undesired result; often referred to as “safe yield.” Perennial yield is similar to the more recent Sustainability Groundwater Management Act (SGMA) definition for “sustainable yield”. The perennial yield may change from year to year depending upon the variability of available sources of water in the watershed. Strategies to prevent Land Subsidence in an active groundwater basin may include reduction of pumping rates from wells and/or a decrease of water exports from the contributing watershed; the installation of injection wells to replenish the aquifer; and planning of other conjunctive-use activities. The important message here is that groundwater management should make certain that Land Subsidence does not occur in the first place in a groundwater basin. The susceptibility of a groundwater basin to Land Subsidence can be evaluated with characterization of the subsurface aquifer systems and evaluation of the entire contributing watershed balance. Tools that are available to measure and evaluate the occurrence of Land Subsidence include extensometers, GPS monitoring stations, InSAR, and traditional land surveying. Considerable information is available via the CA DWR SGMA Data Viewer14. A comprehensive volume of Land Subsidence, which was dedicated to one of the prolific and early investigators (Joseph Poland, PhD – see Figure 1), was published in 199515. Watershed and groundwater basin budgets can also help to determine whether Land Subsidence is operative in a groundwater basin. HV

References: 1. National Ground Water Association (NGWA), 2003, Illustrated Glossary of Ground Water Industry Terms: Hydrogeology, Geophysics, Borehole Construction, and Water Conditioning, published by NGWA, Westerville, Ohio, 69 p. 2.

Todd, David Keith, 1980, Groundwater Hydrology (Second Edition), John Wiley and Sons, Inc., NY, 535 p.

3. Wilson, William E. and John E. Moore (editors), 1998, Glossary of Hydrology, published by the American Geological Institute, Alexandria, VA, 248 p. 4. Bertoldi, Gilbert L., Richard H. Johnston, and K.D. Evenson, 1991, Ground Water in the Central Valley, California: A Summary Report, USGS Professional Paper 1401-A, US Government Printing Office, Washington DC, 44 p. 5.

The classic [examples] given below are in CA (with the exception of sinkhole formation).


Neuendorf, Klaus K.E., James P. Mehl, Jr., and Julia A. Jackson (editors), 2005, Glossary of Geology (Fifth Edition), published by the American Geological Institute, Alexandria, VA, 779 p.

7. Time stamp February 22, 2019 and update April 28, 2021: https:// www.ocregister.com/2019/02/22/sinkholes-are-popping-up-allover-california-thanks-to-the-rain-heres-what-to-know/ 8.

Poehls, D.J. and Gregory J. Smith (editors), 2009, Encyclopedic Dictionary of Hydrogeology, Elsevier Inc, Amsterdam, 517 p.


Time stamp April 28, 2016: https://www.onlyinyourstate.com/ northern-california/sinkholes-in-northern-california/

10. Time stamp March 25, 2021: https://abc7.com/sinkhole-south-losangeles-water-main-break-ladwp/10446821/ 11. Todd, David Keith and Larry W. Mays, 2005, Groundwater Hydrology (Third Edition), John Wiley and Sons, Inc. NY, 636 p. and USGS, https://www.usgs.gov/mission-areas/water-resources/ science/land-subsidence 12. Galloway, Devin, David R. Jones, and S.E. Ingebritson [editors], 1999, Land Subsidence in the United States published by USGS in Circular 1182, 178 p.) Photo from Part 1: Mining Ground Water – Introduction: Santa Clara Valley, CA: A case of arrested subsidence. 13. Abbott, David W., Summer 2019, Notes on Well Development and collecting useful hydraulic information in the process in HydroVisions,Vol. 26, No. 2, published by the Groundwater Resources Association of CA, Wells and Words, pp. 14-19 (last paragraph and Figure 1). 14. https://sgma.water.ca.gov/ webgis/?appid=SGMADataViewer#landsub 15. Borchers, James W. (editor), 1995, Land Subsidence: Case Studies and Current Research, Proceedings of the Dr. Joseph Poland Symposium on Land Subsidence, Association of Engineering Geologists (AEG), Special Publication No. 8, Star Publishing Company, Belmont, CA, 576 p.


Diversity, Equity, and Inclusion GRA’s Newest Committee Inviting Your Support!


or groundwater to be sustainable, it must be equitable. Accepting this simple truth means that we must strive for equity, promote diversity and inclusion throughout GRA and the water industry, and continue to work to achieve our mission of Sustainable Groundwater for All. In 2021, GRA leadership took a major step toward this goal by establishing the Diversity, Equity, and Inclusion (DE&I) Committee.

Diversity, Equity

The Committee began this effort in 2021 by developing three DE&I focused sessions for & Inclusion the Western Groundwater Congress (WGC). In 2022, we aim to build upon these successes by integrating DE&I conversations more broadly, including the GSA Summit, the Law & Legislation Forum, HydroVisions, webcasts, and again at the WGC. We also hope to build partnerships with diverse communities and local and state agencies that will expand our understanding and our reach related to DE&I issues. To accomplish these tasks, we will need your support and engagement! The Committee comprises volunteers from GRA membership who are passionate about this topic. If you are interested in supporting the DE&I Committee, please contact GRA’s DEI Officer, Lyndsey Bloxom at lbloxom@waterrf.org. HV


Drought Conditions and Impacts in the Western United States – Part II by Meeta Pannu, Todd Jarvis, Abhishek Singh, Azita Assadi


he winter of 2021/2022 has been a testament to the hydrologic variability that is characteristic of much of the western United States, which was in the midst of historical and extreme drought conditions headed into the winter of 2021. Over half the region was under “extreme” or “exceptional” drought conditions, with more than 90% under some designated class of drought from moderate to exceptional, as shown in Figure 11. The worst conditions were in Montana, Idaho, Oregon, California, Nevada, and Utah. Heavy precipitation, especially along the West Coast, in October and December 2021 and January 2022 brought some much-needed relief to several of these states, easing the drought conditions to moderate to severe drought in California and most of Washington and Utah as seen in Figure 1. The severity of drought also lessened in Montana, Oregon, and Nevada. Above average snowpacks in the Cascades, Sierras, and Rockies built up through December and January. However, after a promising start to the

season, the rest of Winter was disappointing in terms of rainfall and snowpack. The first two months of 2022 were among the driest on record in several places across the West (e.g., San Francisco’s 2-month total of 0.65 inch eclipsed the record low of 0.72 inch established in January-February 1852) and the early season snowpack effectively flatlined through January and February. At the time of the writing of this article, below-average snowpack was common across the Sierra Nevada, the northern Great Basin (extending into parts of southern and eastern Oregon), and parts of eastern Wyoming and large sections of the Southwest. As such, the “drought watch” across the West is on-going, with over 70% of the West still characterized by severe to exceptional drought conditions. Studies (Williams et al., 2022) indicate that the West is in the midst of the worst protracted “mega drought” in the last 1200 years (2000 – 2021 was the driest 22year period since 800 AD). The drought’s impacts on groundwater will be even longer lasting. Reliance on groundwater only increased

Year 2021 had recordbreaking droughts in much of eastern Washington despite the promising spring snowpack...


during the drought, and winter storms did not translate to enough recharge to alleviate groundwater level declines from the last several years. Having looked at drought conditions in California and Oregon in our first article, the second article of this series shifts focus to the states of Washington and Nevada. Washington Like other western states, Washington relies on surface water for about three-quarters of its freshwater use. Washington state is split by the Cascade Mountains into two distinct climatic regions. The west receives about 50 inches of annual precipitation, which is four times the amount in the east. The snowpack is critical to maintain water supplies in the state, especially in the watersheds of Columbia, Yakima, and Snake Rivers, which are the primary sources of water for eastern Washington. A drought emergency is declared when the water supply is less than 75 percent of average and hardships are anticipated due to low water supply to meet human needs. If drought conditions seem imminent, a drought advisory is declared first to encourage proactive water conservation. Year 2021 had record-breaking droughts in much of eastern Washington despite the promising spring snowpack in the Cascade Range that measured at 132 percent of normal. A historically dry spring and summer, and record-breaking heat wave resulted in a drought emergency for most of the state. March through June precipitation levels tied with 1926 as the second driest period since 1895. Triple digit temperatures in late June worsened the drought conditions. Water temperatures rose in rivers to levels lethal to threatened salmon species. Farmers in eastern Washington had to cut back on irrigation and crops. Dry conditions also lead to wildfires burning the dry vegetation. Twelve significant fires burnt large areas of the state and by July 2021, a total of 900 fires burned at least 220 square miles, which was equal to the total area burned in all of 2019.

Hot and dry conditions in the summer were followed by an unusually wet late fall and winter, with heavy precipitation causing flooding on many western Washington rivers. Despite the wet Figure 1 conditions, nearly half the state remained in some level of drought in January 2022. Nevada Nevada boasts being the driest state in the United States, yet 2021 created abnormally dry conditions with all 17 counties earning USDA disaster designations, despite an unusually wet December that brought more than 100% of normal precipitation to much of the state. The most intense period of drought occurred in July, where exceptional drought affected almost 41 percent of the state. Even with heavy rains in December 2021, almost 100 percent of the state remained in some class of drought with about 20 percent of the state still in extreme to exceptional drought conditions in January 2022. Nevada’s crown jewel, Lake Tahoe, reached within three feet of the historical low surface water level. Almost no flow occurred at the Truckee River outflow during parts of October prior to the atmospheric river events in late October and December. Southern Nevada receives about 90 percent of its water from the Colorado River. The lifeblood of southern Nevada’s water storage system, Lake Mead, reached historically low water levels in 2021 leading to a Tier 1 shortage declaration, which translated to 7% less water. Given the shortfall, Nevada passed a new law outlawing about 31 percent of the grass in the Las Vegas area in an effort to conserve water, making Nevada the first in the nation to enact a permanent ban on certain types of grass. Landscape watering is only allowed one day a week this winter.

Figure 1 - Comparison of Drought Conditions in the Western United States between November 2, 2021, and January 11, 2022 (taken from https:// droughtmonitor.unl.edu/Maps/CompareTwoWeeks.aspx )


Nevada’s groundwater situation is complicated by the fact that most of the state lies within the Basin and Range Province that has 256 separately managed basins. Nevada manages groundwater in these basins using the perennial yield concept which has determined 2 million acre-feet of water per year is potentially available for pumping. The largest groundwater use is for irrigation, comprising 69% of total statewide pumping, the largest of which occurs in Humboldt County along the border of Nevada and Oregon. In 2017, Nevada attempted to make a policy decision to manage surface water and groundwater conjunctively to improve water management, however, water rights issues have confounded its ability to capture streamflow for groundwater recharge. For example, attempts to adopt local market-based systems of water exchanges in the Diamond Valley to forestall curtailments in this basin have been forestalled in court. HV

References: 1. Figure 1 https://droughtmonitor.unl.edu/CurrentMap/ StateDroughtMonitor.aspx?west 2. Drought preparedness and response. Department of Ecology, State of Washington. Available at https://ecology.wa.gov/WaterShorelines/Water-supply/Water-availability/Statewide-conditions/ Drought-response 3. Drought 2021. Department of Ecology, State of Washington. Available at https://ecology.wa.gov/Water-Shorelines/Water-supply/ Water-availability/Statewide-conditions/Drought-2021 4. Williams, A.P., Cook, B.I. & Smerdon, J.E. Rapid intensification of the emerging southwestern North American megadrought in 2020–2021. Nat. Clim. Chang. (2022). https://doi.org/10.1038/ s41558-022-01290-z 5. http://water.nv.gov/documents/Nevada%20Groundwater%20 Pumpage%202017.pdf


GRA is proud to announce the Call for Nominations for our 2022 Awards!


Active participation in one or more GRA committee, previous participation in GRA event planning, or previously volunteered at a GRA event,


Evidence of technical competence, high character and integrity, and

roundwater Resources Association of California is proud to announce the Call for Nominations for our 2022 Awards! Nominations opened on March 15, 2020. Please nominate worthy recipients by April 30, 2022. Lifetime Achievement: Presented to individuals for their exemplary contributions to the groundwater industry, contributions that have been in the spirit of GRA’s mission and organization objectives. Individuals that receive the Lifetime Achievement Award have dedicated their careers to the groundwater industry and have been pioneers in their field of expertise. Kevin J. Neese: Established in 1999 to honor the late GRA Director, geologist, and attorney, the Kevin J. Neese award recognizes a recent, significant accomplishment by a person, persons, or entity that fosters the understanding, development, protection, and management of groundwater. Emerging Groundwater Professional (EGP): A brand new award! This recognition may be awarded annually to active GRA Members who are 35 years of age or less or in the profession/industry 10 years or less during the year of the award and who are judged to have attained significant professional achievement, who have actively participated in a local Branch for at least 1 year, and have shown attributes that may include:


Service to the advancement of the profession,

Leadership in the development of younger member attitudes toward the profession. One EGP from Northern California and one from Southern California will be awarded each year. PRESENTATION Awards are formally presented to all recipients at GRA’s Annual Meeting, which usually takes place in the fall every year at the Western Groundwater Congress. Nominations are open from March 15, 2022, to April 30, 2022, and can be made online at https://www.grac.org/ awards. If you have any questions, comments, or concerns, please reach out to Clay Sorensen (csorensen@balancehydro.com) or Sarah Erck (serck@gra.org). HV

Key Technical Aspects of DWR Reviews on Submitted 2020 GSPs Developed by Lisa Porta, M&A, with input from Marcus Trotta/Sonoma Water, Abhishek Singh/INTERA, and Samantha Adams/West Yost, of the GRA Technical Committee


basin is not pumping more than its overall sustainable yield. he California Department of Water Resources However, a water budget only provides a general view of (DWR) has released their reviews on the the amount of water available in the basin, how much is Groundwater Sustainability Plans (GSP) submitted extracted and replenished and if use of groundwater has by Groundwater Sustainability Agencies (GSAs) in January stayed consistent over time or increased. It does not provide 2020. These first plans were developed for critically an indication of localized impacts on beneficial users overdrafted basins that have to overcome a myriad of water within the basin. This is where Sustainable Management resources challenges to achieve sustainability by 2040. The Criteria (SMCs) and the local definition of undesirable DWR reviews identified deficiencies in a number of GSPs results come into play. Sustainable management is only and provide some insights on improvements to technical truly achievable with an adaptive plan that relies on a wellanalysis, data collection and use, and interpretation of developed monitoring current information, network and policies that as they relate to the trigger action in response Sustainable Groundwater to basin conditions. Management Act (SGMA) DWR provided two types of reviews on the The interplay of water Legislation and the GSP 2020-submitted GSPs: accounting, monitoring, Regulations. and actionable/adaptable One of the key disconnects 1. Approved GSPs with minor deficiencies where policies with robust in the GSPs found to be DWR included recommended corrective actions, stakeholder outreach and deficient by DWR, is that which can be addressed in the 5-year update. engagement provide the sustainability was often 2.GSPs deemed incomplete that have to address best tools for GSAs to measured in terms of a specific deficiencies within 180 days, and resubmit manage their basins for balanced groundwater the GSPs to DWR for review. long-term sustainability. budget – e.g., sustainability

is achieved as long as the


Common Themes from the GSP Evaluations: 1. The primary intent of SGMA is to manage the basin while avoiding undesirable results. 2.Eliminating overdraft is central to SGMA but not the only requirement. 3.Sustainable management criteria need to be developed with consideration of all beneficial uses and users.

In many cases, DWR contends that the SMCs developed for the six sustainability indicators were not backed by robust data or analysis and failed to consider all beneficial users that may be impacted by setting policies based on these criteria. SGMA Sustainability Indicators:

levels at those wells, 3) determining what past levels were too low and have resulted in significant and unreasonable impacts on beneficial users, 4) running simulation models to determine what the groundwater levels may be in the future under projected conditions including land use changes and climate change. DWR’s main comments on chronic lowering of groundwater levels is that domestic well users were not adequately taken into consideration when setting minimum thresholds. One challenge is that domestic well information such as location, depth, screen intervals and pump setting is not adequately documented, and DWR’s online well completion database is incomplete. Despite these data gaps, an initial analysis can be done by intersecting the domestic well density and depth information from DWR, with a contour map of groundwater elevation minimum thresholds. This approach can provide an initial estimate of the percentage of domestic wells that would be impacted if all representative monitoring wells reach the minimum threshold at the same time, as a worst-case scenario estimate. Some GSPs predicted that a small percentage of wells would likely be impacted in the future, and DWR noted that these GSPs should have included specific plans for mitigation. Lastly, it was not deemed acceptable by DWR to set undesirable results at representative monitoring wells such that groundwater levels “fall below their minimum threshold value for two consecutive non-dry water years”. In other words, if exceptions are used for consecutive droughtyears, potential impacts on domestic well owners should be considered and disclosed, or a mitigation plan developed. 2. Land subsidence:

The four major technical aspects of the DWR reviews that need to be considered by GSAs for implementation and to correct deficiencies, include: 1. Groundwater levels 2. Land subsidence 3. Interconnected surface water 4. Data gaps 1. Groundwater levels: Groundwater levels are generally the most straight forward and commonly understood metrics that groundwater managers rely on, as they are easily measured in wells and the effect of chronic lowering of groundwater levels translates directly to failing pumps or dry wells. However, setting criteria such as minimum thresholds to protect wells of varying depths and sizes, needs to include the various stakeholders and all affected beneficial users. Setting minimum thresholds for chronic lowering of groundwater levels requires: 1) identifying the appropriate representative monitoring wells, 2) evaluating historical groundwater 15

Land subsidence affects areas with geology that is prone to compaction (clay layers that can compact under the effect of water withdrawals to levels below historic lows) and with excessive pumping that causes groundwater level declines. Land subsidence becomes an undesirable result if it affects land surface users. Impacts include cracked levees, reduced canal conveyance capacity, and reduced structural integrity of bridges and buildings. SGMA regulates inelastic (e.g., irreversible) pumping-induced subsidence, which can be halted through management of groundwater pumping and control of water level declines. SGMA’s intent is to avoid or minimize land subsidence impacts on beneficial users, and that has not been adequately addressed in some GSPs, according to DWR’s reviews. Thus, there is a need for “additional analysis to understand the significant correlation between groundwater levels and land subsidence, particularly where groundwater levels will continue to decline” (DWR presentation at ACWA) to avoid significant impacts on land users.

the representation of surface water systems, and most The rate of subsidence can only be identified after multiple, numerical groundwater models operate on a monthly time successive ground surface elevation measurements. step, while surface water flow is best measured or assessed Subsidence monitoring primarily includes assessment of on a daily or hourly time ground surface elevations, step. The lack of coupled and often includes flow gage data and shallow groundwater levels. For groundwater levels is a GSPs that rely on using groundwater levels as By 2025, provide the specific methodology challenge to establishing a proxy for monitoring to quantify stream depletion, including the groundwater levels as a proxy for ISW SMC. It is subsidence, DWR expects location, quantity, and timing of depletion even more challenging to an analysis to demonstrate of interconnected surface water”. (DWR establish when and where a significant correlation review letter) the surface flow losses between groundwater are due to pumping and levels and subsidence. if the losses constitute Ground surface elevation a significant and unreasonable effect on beneficial users, can be directly monitored using a variety of methods, including groundwater-dependent ecosystems. Nonetheless, including: while many GSPs did not adequately evaluate ISW, SGMA • Levelling surveys tied to known benchmarks legislation does provide for additional time to further • Global Positioning Systems (GPS) assess it. To practically address ISW in the long-term, the plans will need to include robust monitoring to enable • Borehole extensometer data implementation of the management actions needed. • InSAR data. InSAR is a remote sensing technology that

measures ground elevation using microwave satellite imagery data. DWR provides monthly InSAR data mapped for groundwater basins throughout the state. These data are available starting in June 2015.

Of these techniques, leveling surveys and extensometers provide the most precise data. However, InSAR data provide for basin-scale analysis that may not be feasibly accomplished with extensometers depending on the extent of the area vulnerable to subsidence. 3. Interconnected surface water Interconnected surface water (ISW) with groundwater is an important aspect of sustainable groundwater management because minimizing surface water losses while maximizing groundwater production affects a diverse group of beneficial users of both groundwater and surface water. Interconnected surface water can be depleted when nearby pumping causes surface water to flow towards groundwater. ISW is also the most complex criteria of SGMA as it is the least monitored and understood indicator, and the one that GSAs struggle with the most to develop appropriate policies for management. It is not a coincidence that many GSPs failed to meet the regulations’ expectations for ISW, which require an estimation of “the quantity and timing of depletion of interconnected surface water systems due to groundwater pumping”. This effect is very difficult to measure directly in the field, and modeling tools are often used to estimate 1) where surface water and groundwater are connected, 2) if surface water is losing or gaining relative to shallow groundwater, and 3) the volume or rate of water exchange between surface water and groundwater. Groundwater models have significant uncertainty on

4. Data Gaps:

Many GSAs struggled with a lack of adequate historical data to develop their first comprehensive GSP. Data gaps mostly centered around: • Geologic and hydrogeologic data to understand stratigraphy and groundwater flow between aquifer units • Groundwater pumping, as metering of wells is generally not required outside of public water supply systems • Groundwater levels at an adequate geographic and depth distribution within a basin • Surface water flow and stage measurements • Location and health of groundwater-dependent ecosystems, and instream flow needs by surface water species in ISWs DWR recognizes that these first GSPs did not have all the adequate information available, but stressed the fact that data gaps should be explicitly identified, and a plan developed to fill them over a set period of time during GSP implementation. GSAs are asking DWR and other state agencies to help fill some of the regional data gaps. A number of programs have been developed by DWR to address data gaps, such as: technical support services to install monitoring wells, airborne electromagnetic (AEM) surveys, and access to free InSAR and land use spatial data. However, the cost to adequately fill state-wide data gaps is large and will require additional funding and regional collaboration for efficient data collection.


SGMA Implementation Grant Funding Available for Planning and Projects Development: • Approximately $300 million over 3 years • Fund Planning and Implementation including, but not limited to: • GSP update activities and filling data gaps • Outreach and engagement efforts • Project development, planning, and construction • Proposal Solicitation Package Posted December 2021 • Round 1 solicitation ended February 18, 2022 • Approximately $152M for Award to Critically Overdrafted Basins • Approximately $7.6M available per eligible basin through a modified competitive process • Round 2 Opens Late 2022/Early 2023 • Approximately $205M for Award to non-Critically Overdrafted High/Medium Priority Basins • Traditional Competitive Process More information on the SGM Grant Funding Website

Despite the challenges presented in DWR’s reviews, an important positive effect on the development of GSPs is that it brought together beneficial users in each basin, opened up lines of communication, provided education on very technical and complex aspects of groundwater management, and provided a forum for data and information exchange at the local level and with state agencies. Everyone involved in developing the 2020 and 2022 GSPs has provided tremendous advancement in helping shape the future of sustainable groundwater management in California. HV To learn more, GRA invites you to attend the 5th Annual GSA Summit, June 9th in Sacramento, preceded by GRA’s 2022 Groundwater Law and Legislation Forum the previous day. More information on the DWR reviews can be found at: GSP Status Summary on SGMA Portal: https://sgma.water.ca.gov/ portal/gsp/status Frequently Asked Questions on Next Steps: https://water.ca.gov/-/ media/DWR-Website/Web-Pages/Programs/GroundwaterManagement/Sustainable-Groundwater-Management/GroundwaterSustainability-Plans/Files/GSP/GSP-Incomplete-Assessment-FAQ.pdf


PFAS Fate and Transport Processes and Modeling Approaches by Jeffrey Hale, PGPA, Meeta Pannu, Leila Saberi, Ph.D. and Raghavendra Suribhatla, PhD, PE


he last four articles in this PFAS HydroVisions series have summarized due-diligence, prevalence, release, source-types, monitoring, and treatment of per- and polyfluoroalkyl substances (PFAS). Part 5 of this series continues this discussion with a focus on fate and transport processes as well as modeling approaches for PFAS in water in the subsurface. Fate and transport describe the behavior of a compound once it is released into an environment like water. PFAS source masses are predominantly retained in soils and the unsaturated zone above the water table, sometimes for decades. PFAS are highly soluble and recalcitrant. Once PFAS enter groundwater, their transport is governed by well-known hydrogeologic processes of advection, dispersion and sorption. Occurrence of extensive PFAS plumes may be attributed to fast advective transport as is common in alluvial aquifers and near pumping wells, longer travel times of recalcitrant PFAS from older releases, and multiple non-point sources. Subsurface fate and transport of PFAS is generally governed by: • Degradation (transformation) of precursor compounds to terminal PFAS, and • PFAS sorption to air-water interface (especially in the vadose zone) and solid phases (partitioning), as shown by Figure 1.

These fate and transport processes are influenced by • Porewater chemistry, such as pH and ionic strength of the solution, • Chemical characteristics of individual PFAS, such as functional group (carboxylate or sulfonate), chain length and structural characteristics (e.g., branched or straight chain), and • Nature and type of soil/aquifer matrix (e.g., fraction of organic carbon and positively charged mineral surfaces). Impact of Groundwater Chemistry Sorption to solid surfaces (sediments) and to the airwater interface are the dominant processes controlling PFAS retention and transport. PFAS partitioning to sediments occurs through adsorption to organic carbon via hydrophobic interactions and electrostatic interactions1. The adsorption rate depends on partition coefficients, Kd and Koc (organic carbon normalized adsorption coefficient). Kd values of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) have been found to be correlated with the organic carbon content1. Additionally, lower pH, increased calcium ion activity, and ionic strength of solution tend to promote sorption to aquifer matrices. Due to their unique chemical characteristics, PFAS tend to preferentially accumulate and adsorb at the air-water 18

Figure 1

interface, with high concentrations of PFAS seen at or near the air-water interface within unsaturated pores and at the water table interface. Impact of PFAS Characteristics

Ionic state determines the charge on a compound, which affects its physical and chemical properties. PFAS can dissociate into ions at appropriate pH values. Most PFAAs occur in the environment in anionic (negatively charged) state because of high dissociation constants. The ion associated with the fluoroalkyl part of ionic PFAS can be negatively charged, positively charged, both negatively and positively charged (zwitterion), or nonionic. Cationic and anionic PFAS have different environmental transport behavior. For instance, anion sorption is suppressed at higher pH and cations can be expected to sorb strongly to solids.

PFAS Modeling Tools PFAS fate and transport is also affected by PFAS characteristics such as chain length, extent of fluorination Modeling of PFAS fate and transport in groundwater (per or polyfluorinated PFAS), type of functional group is an active area of research with few tools that can (linear, branched; terminal or precursor) and ionic comprehensively simulate all key processes. These state (polar/non-polar). These properties affect the processes include advection/dispersion in the vadose zone, PFAS partitioning, stability, and transformation in the advection/dispersion in the saturated zone, adsorption environment. For instance, salts of perfluorosulfonic and accumulation at the air-water interface, sorption to acid PFSA are more stable (more persistent) in the the solids (soil) media, and precursor transformations to environment than salts of terminal PFAS. Leaching perfluorinated carboxylic from the vadose zone acid (PFCA)1. PFAS that is typically the most can transform are referred significant source of PFAS Most PFAAs occur in the environment in to as precursors. Biotic to the saturated zone, and anionic (negatively charged) state... and abiotic precursor vertical migration in the transformations occur by vadose zone is heavily processes like hydrolysis, retarded by air-water photolysis and oxidation interfacial adsorption. leading to formation of shorter chain PFAAs, which At high concentrations, PFAS reduces surface tension and primarily occur under ambient conditions. For instance, the impacts flow of water within the vadose zone. Presence of production of PFOA, which is a terminal PFAS, results from any non-aqueous phase liquids (NAPL) presents additional the transformation of a precursor called perfluoro octane complication due to multi-phase flow and partitioning to sulfonyl fluoride (POSF). NAPL phase.

PFAS sorption to organic matter is influenced by its chain length, with higher sorption rates associated with longer chain PFAS1. Additionally, structure of PFAS functional group may influence its sorption rate. For instance, (PFSA) adsorb more readily than (PFCA) of equal chain length due to greater electronegativity. Additionally, perfluorinated molecules are more stable to chemical transformations than polyfluorinated molecules. Figure 1 - Fate and transport processes relevant to PFAS in surface and groundwater matrices³


Figure 2

Amongst the few comprehensive modeling tools are a modified HYDRUS model2 (Silva et al, 2020) and a research tool developed by Brusseau (2019). These research modeling tools are capable of simulating key flow and transport processes and use onedimensional form of the Richards’ equation to simulate vadose zone flow. Transport is simulated using the standard advection-dispersion equation (ADE) with sorption at air-water interface and to solid phase using non-linear isotherms. These modeling tools have been used to test the impact of different sorption isotherms, soil heterogeneities, and sensitivity of PFAS transport to different parameters. Mainstream modeling tools that can simulate key PFAS processes at the field-scale are a critical need for practitioners. Several existing models are currently being evaluated for their applicability to simulate PFAS fate and transport in the vadose zone and groundwater, including MODFLOW-SURFACT, MODFLOW-UZFRT3D, TOUGH-REACT and STOMP. Some groundwater models, like MODFLOW-MT3D, typically only simulate saturated zone fate and transport and must be linked to source models that account for PFAS contributions from the vadose zone. 1-D leaching models, (previously used for metals, chlorinated solvents, and perchlorate) are generally used as screening-level tools and for estimating source loading for subsequent input to groundwater models. This modeling is a fast-evolving area and interested readers are referred to recent studies that summarize the state of the art in modeling tools for PFAS fate and transport.

Notwithstanding the emerging science of PFAS identification and characterization, some important insights have originated from academic research using rigorous lab-scale models. In particular, Brusseau (2019) demonstrated that simplified sorption models are sufficient to model PFAS at low concentrations, paving the way for modification of the traditional ADE modeling tools that have been applied at the field-scale. Apart from modeling tools, currently significant data gaps exist with field-scale sorption and precursor transformation parameters, in addition to large variability in published data3. In the interim, datacentric approaches are filling the gap in assessing PFAS fate and transport. Empirical Resources for Assessing PFAS Fate & Transport A growing body of PFAS groundwater sampling data, relative to known PFAS release locations, are being archived in publicly available databases (California PFAS Geotracker4, New Hampshire PFAS sampling data5), allowing for an empirical assessment of potential and likely migration distances (Figure 2). Such information allows us to 1) assess the validity of modeling results; 2) locate monitoring wells in an informed way; and 3) assess receptor vulnerability relative to know PFAS sources. HV References: Brusseau, Mark. (2019). Simulating PFAS transport influenced by ratelimited multi-process retention. Water Research. 168. 115179. 10.1016/j. watres.2019.115179. Hale, J., 2022, PFOA Empirical Fate & Transport Assessment and Predictive Model, RemTEC Emerging Contaminants Summit [accepted] Silva, Jeff Allen Kai, Jiří Šimůnek, and John E. McCray. “A modified HYDRUS model for simulating PFAS transport in the vadose zone.” Water 12, no. 10 (2020): 2758. 1. https://www.michigan.gov/documents/pfasresponse/Review_of_ Available_Software_for_PFAS_Modeling_Within_the_Vadose_ Zone_699324_7.pdf 2. https://www.ncasi.org/wp-content/uploads/2020/03/Arcadis-PFASResiduals-Modeling-v1-1.pdf 3. https://pfas-1.itrcweb.org/5-environmental-fate-and-transportprocesses/

Figure 2 - Normalized PFOA concentration versus migration distance from source; aggregated from four municipal waste sites in similar hydrogeologic settings (from Hale, 2022).

4. https://geotracker.waterboards.ca.gov/map/pfas_map 5. https://nhdes.maps.arcgis.com/home/index.html


Thursday, June 9th Sterling Hotel, 1300 H Street, Sacramento, CA 95814 , June

GRA wants to recognize all GSAs that have achieved important SGMA milestones this January 2022! High and Medium Priority Basins submitted their GSPs and moved on to implementation Critically Overdrafted Basin GSPs were evaluated by DWR – some were approved, and others need more work. One way or another way all Sustainability Planners are…


Come join us at the GSA Summit to collectively discuss how we translate our sustainability vision into action. Key reasons to attend the Summit this year: •

Celebrate the 7-year anniversary of SGMA implementation and milestones achieved

The GSA Summit is hosted back-to-back with the GRA Groundwater Law and Legislation Forum. Take advantage of two days of legal, policy, and technical insights on all things groundwater.

Learn, network, and collaborate with fellow SGMA enthusiasts

Exchange information, ideas and best practices for successful GSP updates, Data Collection, and GSP Implementation.

This year’s Summit will feature several ways to engage and connect: •

Interactive panel sessions – including a Q&A with DWR and the State Board

Informative presentations and discussions

Stakeholder Outreach Awards

Exhibitors and Sponsorship Opportunities

Celebratory joint reception with the Law and Legislation Forum


https://www.grac.org/events/414/ For more information, contact Abhishek Singh, GRA Director and 2022 GSA Summit Chair (asingh@intera.com)


The Geochemist’s Gallery Toxic Terra (Part 6) by William E. (Bill) Motzer


n Part 5 of this series (Winter 2021-HydroVisions), I discussed natural (geogenic) chromium-6 [Cr(VI)] occurrences in California’s rocks, soil, and groundwater. As indicated in Part 5, most naturally occurring chromium in source rocks and soil are from Cr(III) minerals (e.g., chromite), many of which are relatively water insoluble. However, serpentine soils, precipitation runoff in streams, and groundwater can have soluble Cr(III) cations and Cr(VI) oxyanions (Figure 1; also see and compare with Figure 4 in Part 5). The process of conversion of Cr(III) species to Cr(VI) is a rather interesting geochemical process, requiring the presence of manganese oxides to oxidize slightly soluble Cr(III) to more soluble Cr(VI). Over the last 40 years, this process has been established by experimental and empirical data. Manganese minerals and deposits are also very common in California, particularly in the Coast Ranges, occurring in Franciscan Complex manganiferous cherts.

Figure 1 - Eh-pH stability diagram for Cr(III) and Cr(VI) species in serpentinite soils, groundwater, and streams (Oze, 2003). Figure 2 - Eh-pH stability diagram for Mn-O-C-S at 25o C and 1 atmosphere pressure. Solid Mn species highlighted in gray. Diagram from Hem (1989). Figure 3 - Electrochemical model for sorption of cations (on left) to MnO2 with formation of Cr(VI) oxyanion species such as CrO42‒ and subsequent sorption on ferrihydrite (FeOOH) (on right). Sorption of cations and oxyanions is generally restricted to particle surfaces which may occur at nanometer scales. Diagram modified after Koschinsky and Heim (2017).

Figure 1 The EhpH (redox) diagram in Figure 2 is an example of how different manganese species form in groundwater. Comparing Figures 1 and 2, note that the stability zones for Cr(VI) species are in similar positions as those for Mn(IV) species (Figure 2 gray shaded areas). What occurs is that Mn oxides in insoluble Mn minerals, such as bernessite (MnO2•nH2O), “catalyze” and oxidize Cr(III) species to Cr(VI). Bernessite( δMnO2) and other MnO2 polymorphic1 minerals tend to sorb Cr cations because they have negative charges (see Figure 3).

In California, groundwater in alluvial aquifers underlying or adjacent to ultramafic rock and serpentinite source rock may contain Cr(VI) oxyanions. Geochemical conditions favoring Cr(VI) formation include the presence of (1) 22

Figure 2

oxygenated water, i.e., high Eh, (2) alkaline water, i.e., pH ≥ 7.0, and (3) manganese oxides, particularly Mn(IV) oxides. Additionally, for Cr(VI) to form, aquifer materials should be low in ferrous iron [Fe(II)], organic matter, and clays (e.g., aluminum oxides) that may be Cr(VI) adsorbents and reductants that either prevent formation of Cr(VI) or transform it back to Cr(III). Cr(VI) may also be sorbed to hydrous ferrous oxides occurring either as coatings on quartz sand grains or as weathered iron oxides (e.g., hematite, i.e., Fe2O3). These materials may be storage sites for Cr(VI) oxyanions. Naturally-occurring Cr(VI) in groundwater collected from wells is generally in the low μg/L (ppb) range. However, U.S. Geological Survey studies of California groundwater have determined that 4.5 percent of 918 sampled wells had Cr(VI) exceeding the former California Cr(VI) maximum contaminant level (MCL) of 10 ppb. (Note: see Part 5 for an explanation of the status of the Cr(VI) MCL). Once Cr(III) species are oxidized to Cr(VI), hydrous ferrous oxides (HFOs), such as ferrihydrite (generally, FeOOH • nH2O), become the predominant sorptive substances for complex oxyanions, such as CrO42–, because these HFOs have positive surface charges (Figure 3). Therefore, HFOs likely act as “storage” sites for Cr(VI) oxyanions. This condition is important because, as infiltrating water percolates downward through the unsaturated zone, the water tends to “remobilize” the sorbed Cr(VI), which then accumulates in groundwater. HV Figure 3

1Manganese dioxide (MnO2) occurs in several different polymorphic

forms (aka polymorphs), which are minerals that have the same chemical compositions but different crystal forms or structures. For MnO2 different Greek letters are assigned to the different polymorphs, i.e., hollandite (α), pyrolusite (β), intergrowth (γ), birnessite (δ), and defect spinel structures (λ).

Disclosure and Acknowledgement Portions of this research were conducted for a recycled water project while employed by Todd Groundwater in Alameda, CA; with special thanks to P. Stanin, the late E. Lin, I. Priestaf, G. Yates, and S, McCraven.

References for Parts 5 and 6 Hem J.D., 1989 (third edition), Study and Interpretation of the Chemical Characteristics of Natural Water: U.S. Geol. Survey Water Supply Paper 2254, USGS, Alexandria, VA, 263 p. Izbicki, J.A., Wright, M.T., Seymour, W.A., McCleskey, R.B., Fram, M.S., Belitz, K., and Esser, B.K., 2015, Cr(VI) Occurrence and Geochemistry in Water from Public Supply Wells in California: Applied Geochemistry, v.63, pp. 203-217. Koschinsky, A. and Heim, J.R., 2017, Marine Ferromanganese Encrustations: Archives of Changing Oceans: Elements, v. 13, n. 3, pp. 177–182. Morrison, J.M., Goldhaber, M.B., Lee, L., Holloway, J.M., Richard B. Wanty, J.B., Wolf, R.E., Ranville, J.F., 2009, A Regional-scale Study of Chromium and Nickel in Soils of Northern California, USA: Applied Geochemistry, v.24, pp. 1500–1511. Motzer, W.E., 2005, Chemistry, Geochemistry, and Geology of Chromium and Chromium Compounds (Chapter 2), in J. Guertin, J.A. Jacobs, and C.P. Avakian (editors), Chromium(VI) Handbook – Independent Environmental Technical Evaluation Group (IETEG), CRC Press, Boca Raton, FL, pp. 23-91. Motzer, W.E., 2017, Toxic Terra – Parts 10 and 11 (Chromium): The Vortex, v. LXXIX, n. 6 and 7, pp. 6-7, www.calacs.org. Motzer, W.E. and Petrofsky, M., 2018, Field Guide to the Unique Geology/Geochemistry of Ring Mountain Open Space Preserve (RMOSP), Marin, County, CA: Northern California Geological Society, 30 p., http://www.ncgeolsoc.org Oze, C., 2003, Chromium Geochemistry of Serpentinites and Serpentine Soils: Stanford University Doctoral dissertation, 198 p. Oze, C., Bird, D.K., and Fendorf, S., 2007, Genesis of Hexavalent Chromium from Natural Sources in Soil and Groundwater: Proceedings of the National Academy of Sciences (PNAS), v. 104, n. 16, pp. 6544– 6549. Priestaf, M.J. and Rednock, D., 2015, An Electrochemical Study of Chromium Oxidation by Manganese Oxides: Geological Society of America Abstracts with Programs, v. 47, n.7, pp. 301, https://gsa. confex.com/gsa/2015AM/webprogram/Paper269901.html. Snyder, W.S., 1978, Manganese Deposited by Submarine Hot Springs in Chert-Greenstone Complexes, Western United States: Geology, v. 6, pp. 741-744. Taliaferro, N.L., and Hudson, F.S, 1943, Genesis of the Manganese Deposits of the Coast Ranges of California, in Manganese in California: California State Division of Mines (CSDM) Bulletin No. 125, CSDM, Ferry Building, San Francisco, pp. 217-275. Trask, P.D., Wilson, I.F. and Simons, F.S.,1943, Manganese Deposits of California: A Summary Report, in Manganese in California: California State Division of Mines (CSDM) Bulletin No. 125, CSDM, Ferry Building, San Francisco, pp. 51-216.


ISMAR Is Nearly Here!


he 11th International Symposium on Managed Aquifer Recharge is just around the corner, April 1115, 2022 in beautiful Long Beach, California.

ISMAR11 includes three pre-conference workshops, keynote speakers, two days of multi-track technical sessions, the Herman Bouwer Awards luncheon, post-conference field trips, post conference geophysics workshop, networking, socializing, and networking opportunities.

Pre-Conference Workshops & Field Trips Join us on April 11th at 8am for our pre-conference session; Achieving Successful Groundwater Recharge and Recovery Through Wells. The aim of this workshop is to provide attendees with an appreciation and practical understanding of the technical, scientific, engineering design, and other issues that need to be addressed when developing managed aquifer recharge (MAR) systems that utilize wells, whether aquifer recharge (AR) wells, aquifer storage recovery (ASR) wells or aquifer storage transfer recovery (ASTR) wells.

Online registration closes on March 28, 2022.

Online registration closes on March 28, 2022. So be sure to sign up today! Kicking off the conference is a keynote address on leadership in water by former Arizona Governor and Secretary of the Interior Bruce Babbitt. He will be followed by Dr. David Kreamer, professor of Hydrology at the University of Nevada, Las Vegas and current president of IAH. To dive into the policy and governance issues related to MAR are two curated panels, one moderated by Felicia Marcus focused on MAR in California and the other by Dr. Sharon Megdal focused on MAR in Arizona, Israel and other areas. Dr. Megdal is also offering a pre-conference workshop on the role of MAR governance and policy in meeting water management objectives.

On April 15th at 8:30am we will be taking a field trip to both Orange County Water District and Water Replenishment District of Southern California. Please note that a separate registration is required for the pre-con sessions and the field trips. And if all the great content and networking opportunites wasn’t enough to convice you, on Wednesday evening from 8pm - 11pm we will be dressed up and get ready to enjoy big-band music, drink and dessert bar, photo booth and casino games at ISMAR’s speakeasy event featuting Sergio Vellatti, Big Band Music 24

You won’t want to miss this event. So, whether you are a MAR veteran, someone new to MAR, a policy maker or board member, there is something for you at ISMAR 11. And check out the draft program here: https://www.grac. org/ismar-agenda-highlights/ ISMAR 11 will be held at the Hilton Long Beach, which is a tremendous venue that is close to multiple restaurants and other attractions. ISMAR 11 will run from April 11-15, 2022. To register go to ismar11.net. HV

2022 Spring Issue | Authors

John Karachewski is a geologist for the California EPA (DTSC) in Berkeley. He is an avid photographer and often teaches geology as an instructor and field trip leader. David W. Abbott, P.G., C.Hg., Consulting Geologist is a Geologist with 45+ years of applied experience in the exploration and development of groundwater supplies; well location services; installation and design of water supply wells; watershed studies; contamination investigations; geotechnical and groundwater problem solving; and protection of groundwater resources. Bruce K. Marvin, P.E. is a Senior Principal at Geosyntec Consultants in Oakland, CA. Bruce works on PFAS, remediation, and redevelopment projects nationwide. He was co-chair of the GRA Technical Committee and a co-author of several Interstate Technology and Regulatory Council guidance manuals on DNAPL, chemical and biological remediation methodologies. He is an advisor to research teams at two universities investigating PFAS remediation technologies. John Merrill is an Engineer at Geosyntec Consultants in Oakland, CA. John works on PFAS projects nationwide involving site investigation and remediation, litigation support, environmental due diligence, and applied research. Funded by the U.S. Department of Defense, he is helping develop lines of evidence to assess the effectiveness of PFAS remedial technologies. Balaji Seshasayee, P.E. is a Project Engineer at Geosyntec Consultants in Chicago, IL. Balaji works on groundwater treatment solutions for PFAS and other emerging contaminants, including technology evaluation, treatability testing, and treatment system design. His experience includes the analysis and design of fixed-bed adsorbers as well as other unit processes for water treatment. Manmeet “Meeta” Pannu, Ph.D., is a Senior Scientist in the Research and Development Department of Orange County Water District (OCWD) at Anaheim, CA. Meeta is currently completing research at OCWD related to PFAS. These projects include evaluation of GAC, IX, and alternative adsorbents to remove PFAS from groundwater during wellhead treatment. Meeta also works on managed aquifer recharge evaluating insitu adsorption and alternative methods to measure total PFAS in water samples. William E. (Bill) Motzer, PHD, PG, CHG, is a somewhat retired Forensic Geochemist Jeffrey Hale, PGPA is the Practice Leader for Woodard & Curran’s Emerging Contaminants group. He provides consultation, strategy, and direction for challenging environmental and natural resources issues with emphasis on PFAS, emerging contaminants, complex sites, remediation, liability management, and environmental forensics.

#ISMAR11 Please visit www.ismar11.net for more information.

Leila Saberi, Ph.D. is a Hydrogeologist at INTERA, LA, CA. Leila’s work focuses on groundwater flow and transport simulations using multiand single-phase hydrological and reactive transport models including TOUGH, MODFLOW-MT3D, MODPATH, and MODFLOWSURFACT. Additionally, she implements uncertainty and sensitivity analysis for model calibration and uncertainty quantifications in model simulations using tools such as PEST++ and PyEmu. The primary objective of these projects is to evaluate contaminant transport and seawater intrusion through the saturated and unsaturated zones to provide strategies for a comprehensive water quality and quantity management plan. Raghavendra (Raghu) Suribhatla, PhD, PE is a Senior Engineer and Technical Services Manager for INTERA’s California projects. He serves as modeling manager for water resources and recycled water projects in Southern California, and is the lead engineer for preparation of regulatory reports for seawater barrier projects in Los Angeles and Orange Counties.



Parting Shot By John Karachewski


ijuana Slough National Wildlife Refuge is a 1,072acre wetland located where the Tijuana River meets the ocean near Imperial Beach. The refuge was established in 1980 and is part of the 2,800-acre Tijuana River National Estuarine Research Reserve, one of only 28 such reserves in the United States. This Refuge was designated as a Wetland of International Importance by the Ramsar Wetlands Convention. The international scope of the Tijuana River watershed, the diversity of habitats, and the range of human and physical problems facing the Reserve make the area rich for study in both the biological and social sciences. The Tijuana River National Estuarine Research Reserve preserves, protects, and manages the natural and cultural resources of the Tijuana River Estuary by focusing on research and education with compatible recreation and resource use. The Reserve encompasses beach, dune, mudflat, salt marsh, riparian, coastal sage scrub, and upland habitats surrounded by the growing cities of Tijuana, Imperial Beach, and San Diego. Critical issues confronted by the Reserve include habitat conservation and restoration, endangered species management, management of the wastewater from Mexico, sediment management, and the integration of recreation. The Tijuana Estuary participates in the National Estuarine Research Reserve System Wide-Monitoring Program. Three data loggers are used to measure water depth, temperature, salinity, dissolved oxygen, turbidity, and pH at 30-minute intervals, and the Boca Rio station is shown above. The data are available at: https://trnerr.org/system-wide-monitoringprogram/. HV Photographed along the River Mouth Loop trail at the Tijuana Slough National Wildlife Refuge on October 21, 2021, by John Karachewski, PhD. Photograph taken at 32.559647° and -117.128755°. For additional information, refer to: Tijuana Slough National Wildlife Refuge and Tijuana River National Estuarine Research Reserve



Another year of incredible GRA Events!


ome immerse yourself in two days of groundwater law, legislation, SGMA policy, GSA management, and GSP implementation at the back-to-back “Law and Legislative Forum” and the “GSA Summit”. The two events are combined this year (with a discounted rate and joint reception) and packed with interactive learning, discussion, and panels!

And be sure to check out the many Branch Meetings, GRACasts and other perioiduc training opportunitis that pop up, all which can be found here: https://www. grac.org/events/search/



Tier One Sponsors

Tier Two Sponsors

Thank You For Your Support! 29