CV-SALTS Groundwater Sustainability Plan Data Integration Report Integrated Scope of Work - Task 5.3 (Draft)

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | June 20th, 2024

The purpose of Prioritization & Optimization (P&O) Study Task 5.3 (Information Extraction from Groundwater Sustainability Plans [GSP]) is to extract and organize

The purpose of Prioritization & Optimization (P&O) Study Task 5.3 (Information Extraction from Groundwater Sustainability Plans [GSP]) is to extract and organize relevant GSP data and information that can be used to: Validate or refine information contained in the P&O Study’s Central Valley Soil and Water Assessment Tool (CV-SWAT) watershed model and other models (developed to support ongoing baseline characterization work and future salinity-related analyses); Support the eventual development of salinity management alternatives within specified Central Valley planning areas; and Help ensure that long-term Central Valley salt planning understands and considers ongoing Groundwater Sustainability Agency (GSA) planning efforts, efforts and potential future conditions of the water in the Central Valley region and benefits from the local investment in these plans. It is also expected that this report will be a foundation for enhanced coordination with GSAs as planning occurs in their regions. Click below for document appendices.  Appendix A: Selected GSP Information Summaries by Hydrologic Region Appendix B: Appendix B 1 - Sac Valley Hydrologic Region - GSP Hydrogeologic Conceptual Model Excerpts and Near AEM Profiles Appendix B 2 - San Joaquin Valley Hydrologic Region - GSP Hydrologic Conceptual Model Excerpts and Near AEM Profiles Appendix B 3 - Tulare Lake Hydrologic Region - GSP Hydrogeologic Conceptual Model Excerpts and Near AEM Profiles

CV-SALTS Prioritization & Optimization Study: Final Baseline Characterization Report

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | March 9th, 2024

The Central Valley Regional Water Quality Control Board (Central Valley Water Board) first adopted a three-phased Salt Control Program into the water quality regulations

The Central Valley Regional Water Quality Control Board (Central Valley Water Board) first adopted a three-phased Salt Control Program into the water quality regulations applicable to the Central Valley Region of California in 2018; these regulations were subsequently amended in 2020. Phase I of the Salt Control Program requires implementation of the Prioritization and Optimization (P&O) Study. The primary purposes of this Study are to characterize existing salinity conditions in surface water and groundwater in the Central Valley Region, establish appropriate salinity targets for the protection of beneficial uses, and facilitate the development of long-term salt management alternatives for implementation in Phases II and III of the Salt Control Program.

Delineation of Spatial Extent, Depth, Thickness, and Potential Volume of Aquifers Used for Domestic and Public Water-Supply in the Central Valley, California

U.S. Geological Survey (USGS) | September 5th, 2019

Identification of the groundwater resources used for drinking-water supplies is essential for the design of strategies to manage those resources. In this study, t

Identification of the groundwater resources used for drinking-water supplies is essential for the design of strategies to manage those resources. In this study, the spatial extent, depths, thicknesses, and volumes of groundwater aquifers used for domestic and public drinking-water supply were estimated from locations and well-construction data from 11,725 domestic-supply wells and 2,376 public-supply wells in the Central Valley, California. The data were compiled as part of the U.S. Geological Survey National Water Quality Assessment Project and California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment Program Priority Basin Project. The spatial distributions of the depth to top and bottom of well screens were interpolated using Empirical Bayesian Kriging across buffer areas surrounding domestic- and public-supply wells. These surfaces provide a measure of the likely maximum horizontal and vertical extent of the aquifer volume accessed for drinking water in the Central Valley during the past century. Well depth generally increased from north to south, and over time from 1905 to 2010. Well-construction depths were generally more consistent in the Sacramento Valley than in the San Joaquin Valley. The total potential aquifer volume accessed for public supply was calculated to be greater than domestic-supply access, even though the estimated spatial extent of domestic-supply wells was 1.5 times larger than the spatial extent of public-supply wells. Public-supply wells commonly have screen lengths greater than 51 meters, whereas domestic-supply wells typically have shorter screen lengths (overall median of 6 meters). Consequently, the accessed thickness and volume of the aquifer is on average 1.8 and 1.4 times greater for public-supply wells than domestic- supply wells, respectively. Results are presented as maps of areal extent, depth, and thickness of zones in the Central Valley aquifer system used for domestic and public drinking- water supplies.

Delta Vision Strategic Plan

State of California | October 17th, 2008

When it was created by Governor Schwarzenegger’s Executive Order S-17-06 in 2006, the charge of the Delta Vision Blue Ribbon Task Force (Task Force) was nothing less th

When it was created by Governor Schwarzenegger’s Executive Order S-17-06 in 2006, the charge of the Delta Vision Blue Ribbon Task Force (Task Force) was nothing less than to create a vision to repair the ecological damage to the Sacramento-San Joaquin River Delta (Delta), and then prepare a strategic plan which would sustain the Delta in future decades while ensuring a reliable water supply for the two-thirds of California’s population who depend in whole or in part on water from the Delta.

Delta Vision Strategic Plan -- from Phil Isenberg, 1939-2023

State of California | October 17th, 2008

When it was created by Governor Schwarzenegger’s Executive Order S-17-06 in 2006, the charge of the Delta Vision Blue Ribbon Task Force (Task Force) was nothing less th

When it was created by Governor Schwarzenegger’s Executive Order S-17-06 in 2006, the charge of the Delta Vision Blue Ribbon Task Force (Task Force) was nothing less than to create a vision to repair the ecological damage to the Sacramento-San Joaquin River Delta (Delta), and then prepare a strategic plan which would sustain the Delta in future decades while ensuring a reliable water supply for the two-thirds of California’s population who depend in whole or in part on water from the Delta.

Demographic predictors of urinary arsenic in a low-income predominantly Hispanic pregnancy cohort in Los Angeles

Journal of Exposure Science & Environmental Epidemiology (Springer) | July 27th, 2020

Arsenic (As) is a contaminant of top public health concern, due to its range of detrimental health effects. Arsenic exposure has not been well-characterized among the US

Arsenic (As) is a contaminant of top public health concern, due to its range of detrimental health effects. Arsenic exposure has not been well-characterized among the US Hispanic populations and has been particularly understudied in this population during pregnancy. As part of the MADRES ongoing pregnancy cohort of predominantly lower-income, Hispanic women in Los Angeles, CA, we examined levels of maternal first trimester urinary As, including total As and As metabolites (inorganic (iAs), monomethylated (MMA) and dimethylated As (DMA)), in relation to participant demographics, lifestyle characteristics, and rice/seafood consumption, to identify factors that may influence As exposure and its metabolites during pregnancy (N = 241). Total As concentrations ranged from low to high (0.8–506.2 μg/L, mean: 9.0 μg/L, SD: 32.9) in our study population. Foreign-born Hispanic women had 8.6% higher %DMA (95% CI: 3.3%, 13.9%) and −7.7% lower %iAs (95% CI: −12.6%, −2.9%) than non-Hispanic women. A similar trend was observed for US-born Hispanic women. In addition, maternal age was associated with 0.4% higher %iAs (95% CI: 0.1%, 0.6%) and 0.4% lower %DMA (95% CI: −0.7%, −0.1%) per year, which may indicate poor As methylation capacity. Individual factors may predict As exposure and metabolism in pregnancy, and in turn, greater risk of adverse health effects.

Detecting community response to water quality violations using bottled water sales

National Academy of Sciences (NAS) | September 30th, 2019

Direct potable reuse: a future imperative

International Water Association (IWA) Publishing | March 1st, 2011

As a result of population growth, urbanization, and climate change, public water supplies are becoming stressed, and the chances of tapping new water supplies for

As a result of population growth, urbanization, and climate change, public water supplies are becoming stressed, and the chances of tapping new water supplies for metropolitan areas are getting more difficult, if not impossible. As a consequence, existing water supplies must go further. One way to achieve this objective is by increased water reuse, particularly in supplementing municipal water supplies. Although water reuse offers many opportunities it also involves a number of problems. A significant cost for nonpotable water reuse in urban areas is associated with the need to provide separate piping and storage systems for reclaimed water. In most situations, the cost of a dual distribution system has been prohibitive and thus, has limited implementation for water reuse programs. The solution to the problem of distribution is to implement direct potable reuse (DPR) of purified water in the existing water distribution system. The purpose of this paper is to consider (a) a future in which DPR will be the norm and (b) the steps that will need to be taken to make this a reality. Following an overview, the rationale for DPR, some examples of DPR projects, technological and implementation issues, and future expectations are examined.

Distributions of waterborne pathogens in raw wastewater based on a 14-month, multi-site monitoring campaign

Water Research | February 9th, 2022

The California State Water Resources Control Board is the first regulatory body in the United States to develop statewide regulations for direct potable reuse (DPR). To s

The California State Water Resources Control Board is the first regulatory body in the United States to develop statewide regulations for direct potable reuse (DPR). To support this effort, a pathogen monitoring campaign was undertaken to develop and implement an optimized standard operating protocol to better characterize the concentration of human pathogens in raw wastewater. Methods to detect relevant viral and protozoan pathogens in raw wastewater were optimized and implemented during a 14-month monitoring campaign. Over 120 samples were collected from five wastewater treatment plants treating a quarter of California's population. Samples were analyzed for two protozoa (Cryptosporidium and Giardia) using microscopy methods, three enteric viruses (enterovirus, adenovirus, and norovirus) using culture and/or molecular methods, and male-specific coliphage using culture methods. The method recovery efficiency was measured in every protozoa sample and every other virus sample to confirm minimum recovery efficiencies were achieved and to correct the concentrations for pathogen losses during sample processing. The results from this study provide the industry with a large, high-quality dataset as demonstrated by the high degree of method sensitivity, method recovery, and QA/QC steps. Such high-quality data on pathogen concentrations in raw wastewater are critical for confirming the level of treatment needed to reduce pathogen concentrations down to acceptable levels for potable water in DPR projects.

Domestic well vulnerability to drought duration and unsustainable groundwater management in California's Central Valley

Environmental Research Letters (IOP) | March 18th, 2020

Millions of Californians access drinking water via domestic wells, which are vulnerable to drought and unsustainable groundwater management. Groundwater overdraft and th

Millions of Californians access drinking water via domestic wells, which are vulnerable to drought and unsustainable groundwater management. Groundwater overdraft and the possibility of longer drought duration under climate change threatens domestic well reliability, yet we lack tools to assess the impact of such events. Here, we leverage 943,469 well completion reports and 20 years of groundwater elevation data to develop a spatially-explicit domestic well failure model covering California’s Central Valley. Our model successfully reproduces the spatial distribution of observed domestic well failures during the severe 2012–2016 drought (n=2027). Next, the impact of longer drought duration (5–8years) on domestic well failure is evaluated, indicating that if the 2012–2016 drought would have continued into a 6 to 8 year long drought, a total of 4037–5460 to 6538–8056 wells would fail. The same drought duration scenarios with an intervening wet winter in 2017 lead to an average of 498 and 738 fewer well failures. Additionally, we map vulnerable wells at high failure risk and find that they align with clusters of predicted well failures. Lastly, we evaluate how the timing and implementation of different projected groundwater management regimes impact groundwater levels and thus domestic well failure. When historic overdraft persists until 2040, domestic well failures range from 5966 to 10 466 (depending on the historic period considered). When sustainability is achieved progressively between 2020 and 2040, well failures range from 3677 to 6943, and from 1516 to 2513 when groundwater is not allowed to decline after 2020.