Quality of Groundwater Used for Domestic Drinking-Water Supply in the Coachella Valley, 2020

U.S. Geological Survey (USGS) | January 13th, 2023

Quality of Groundwater Used for Domestic Supply in the Northern San Joaquin Valley, California

U.S. Geological Survey (USGS) | July 28th, 2021

 Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Moni

 Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project (PBP) of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and provides increased public access to groundwater-quality information. Private domestic and small-system drinking-water wells in the Northern San Joaquin Valley (NSJV) were the target for this assessment. These wells tend to pump water from shallower parts of alluvial aquifers compared to deeper, long-screened public-supply wells in the region. 

Quality of Groundwater Used for Public Supply in the Continental United States: A Comprehensive Assessment

American Chemical Society (ACS) | October 21st, 2022

Quality of Water from Domestic Wells in Principal Aquifers of the United States, 1991–2004: Overview of Major Findings

U.S. Geological Survey (USGS) | November 5th, 2009

This report is one of a series of publications, The Quality of Our Nation’s Waters, which describes major findings of the NAWQA Program on water-quality issues of regio

This report is one of a series of publications, The Quality of Our Nation’s Waters, which describes major findings of the NAWQA Program on water-quality issues of regional and national concern. This report presents a national assessment of the quality of water in private domestic wells based on samples from about 2,100 wells located in 48 states and tapping 30 regional aquifers used for water supply. Compared to previous investigations of domestic well water quality, “Quality of Water from Domestic Wells in Principal Aquifers of the United States, 1991–2004 —Overview of Major Findings” greatly expands the number of contaminants assessed in domestic wells and improves geographic coverage of wells sampled. More than 43 million people—about 15 percent of the U.S. population—rely on domestic wells as their source of drinking water (Hutson and others, 2004). The quality and safety of water from domestic wells, also known as private wells, are not regulated by the Federal Safe Drinking Water Act or, in most cases, by state laws. Rather, individual homeowners are responsible for maintaining their domestic well systems and for monitoring water quality. The lack of regular monitoring of domestic wells makes periodic assessments at national, regional, and local scales important sources of information about this key source of drinking water. This study from the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS) assesses water-quality conditions for about 2,100 domestic wells. The sampled wells are located in 48 states and in parts of 30 regionally extensive aquifers used for water supply in the United States. As many as 219 properties and contaminants, including pH, major ions, nutrients, trace elements, radon, pesticides, and volatile organic compounds (VOCs), were measured. Fecal indicator bacteria and additional radionuclides were analyzed for a smaller number of wells. The large number of contaminants assessed and the broad geographic coverage of the present study provides a foundation for an improved understanding of the quality of water from the major aquifers tapped by domestic supply wells in the United States.

Quality of Water from Public-Supply Wells in the United States, 1993–2007: Overview of Major Findings

U.S. Geological Survey (USGS) | July 12th, 2010

In this study by the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS), chemical water-quality conditions were assessed in source (un

In this study by the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS), chemical water-quality conditions were assessed in source (untreated) groundwater from 932 public-supply wells, hereafter referred to as public wells, and in source and finished water from a subset of 94 wells. The public wells are located in selected parts of 41 states and withdraw water from parts of 30 regionally extensive water-supply aquifers, which constitute about one-half of the principal aquifers in the United States. Although the wells sampled in this study represent less than 1 percent of all groundwater-supplied public water systems in the United States, they are widely distributed nationally and were randomly selected within the sampled hydrogeologic settings to represent typical aquifer conditions. All source-water samples were collected prior to any treatment or blending that potentially could alter contaminant concentrations. As a result, the sampled groundwater represents the quality of the source water and not necessarily the quality of finished water ingested by the people served by these public wells.

Responses of drinking water bulk and biofilm microbiota to elevated water age in bench-scale simulated distribution systems

Biofilms and Microbiomes (Nature) | January 22nd, 2024

Safe Drinking Water Plan for California

California State Water Resources Control Board (SWRCB) | June 9th, 2015

In 1993, the California Department of Health Services (CDHS) (now the California Department of Public Health (CDPH) submitted to the Legislature the report entitled, "Dri

In 1993, the California Department of Health Services (CDHS) (now the California Department of Public Health (CDPH) submitted to the Legislature the report entitled, "Drinking Water into the 21st Century: Safe Drinking Water Plan for California" (1993 Plan). In 1996, the California Legislature enacted Senate Bill (SB) 1307 (Chapter 755, Statutes of 1996). SB 1307 amended Health and Safety (H&S) Code Section 116355 to require a periodic update of the original Plan. The issues that were to be addressed were essentially the same as those included in the 1993 Plan. CDPH assembled a team of experts that conducted extensive reviews and analyses, resulting in a draft plan that included an overview of drinking water regulation, reviews and plans for drinking water quality/monitoring and threats, treatment technologies, funding aspects and financial assistance, and a focus on the challenges faced by small drinking water systems. Following the July 1, 2014 transition of the Drinking Water Program to the State Water Board, the draft plan’s recommendations and implementation plan has been enhanced based on the synergies and resources resulting from incorporation of the program into the State Water Board.  California continues to be dependent on a mixture of surface water and groundwater supplies for drinking water. The degree to which each type of supply is used in a given year is dependent upon the region of the state, water needs, water resource availability, and climatologic conditions within the state. During periods of normal to high rainfall, surface water sources make up a higher percentage of the overall drinking water supplies across the state. However, during periods of lower than average rainfall, use of groundwater increases and surface water supplies are strained. As California’s population has grown since the 1993 Plan was published, the demand on the State’s limited water resources have increased. To meet this demand, many public water systems (PWS) have promoted conservation measures as well as looked to other potential sources of supply such as recycled water and desalination. Mirroring the regulatory scope of the Division of Drinking Water, the scope of this Plan focuses on the state’s public water systems (PWS), as defined in Health and Safety Code 116275(h). These are systems that either have (a) 15 or more service connections or (b) systems that serve at least 25 individuals daily at least 60 days out of the year. There are currently more than 7,600 PWS in the state. This is a significant reduction from the more than 10,000 that were in existence in 1993.  However, California’s population has grown from approximately 29 million to over 38 million. Of those 7,600 PWS, approximately seven percent serve communities with more than 10,000 service connections (approximately 33,000 people). The majority of PWS serve smaller communities with more than 63 percent of PWS serving communities with less than 200 service connections (approximately 660 people). Many of the small PWS are challenged by lack of technical, managerial, and financial (TMF) capacity; many do not serve drinking water that meets standards (“safe drinking water”). In 2012, California became the first state to enact a Human Right to Water law, AB 685 (Chapter 524, Statutes of 2012). Public policy continues to be focused on the right of every human being to have safe, clean, affordable, and accessible water adequate for human consumption, cooking, and sanitation. Water supply, contaminants, costs of treatment and distribution systems, the number and nature of small PWSs, especially in disadvantaged communities, and many other factors will continue to challenge progress in addressing the Human Right to Water. The State Water Board is committed to actively pursuing initiatives to address the Human Right to Water, beginning with the state’s residents who are served by PWS but who do not receive safe drinking water.

Safe Drinking Water Plan for California: Report to the Legislature in Compliance with Health and Safety Code Section 116365

California State Water Resources Control Board (SWRCB) | June 8th, 2015

The State Water Board recognizes that to fulfill the Human Right to Water in California, every resident should have access to affordable, safe drinking water regardless

The State Water Board recognizes that to fulfill the Human Right to Water in California, every resident should have access to affordable, safe drinking water regardless of the water system size. Provided data become available on this topic, in a future update of the Safe Drinking Water Plan the Water Board could expand the scope to include systems below 15 service connections, but to do that would require new and expanded authority, significantly more resources, as well as commitment and involvement of other local and state agency partners. At this time, this report contains 32 practical recommendations in 9 areas that would expand the State Water Board’s efforts to bring a greater number of systems into compliance and contribute to realizing the Human Right to Water in California. Each chapter provides a background discussion covering the areas mandated by the Legislature including a description of problems and issues and a set of conclusions and recommendations with the basis and justification for them. A detailed five-year implementation plan addressing the major recommendations is provided in Appendix 10.

Salinity Effects on MUN‐Related Uses of Water

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | December 1st, 2016

Purpose: Summarize current state of knowledge regarding the effects of elevated conductivity, salinity or TDS and hardness on drinking water supply

Purpose: Summarize current state of knowledge regarding the effects of elevated conductivity, salinity or TDS and hardness on drinking water supply and other domestic purposes for water use. Identify/summarize unique concerns related to specific ions (e.g. sodium, chloride, boron, etc.).

San Gabriel Valley Superfund Sites Progress Updates

U.S. Environmental Protection Agency (EPA) | May 31st, 2021