Environmental and anthropogenic drivers of contaminants in agricultural watersheds with implications for land management

Science of the Total Environment (Elsevier) | February 17th, 2021

Environmental Baseline Archeological and Historical Resources, Total Water Management Study for the Central Valley Basin, California

U.S. Bureau of Reclamation (USBR) | January 1st, 1975

Environmental Baseline Biological Resources - Fauna, Total Water Management Study for the Central Valley, California

U.S. Bureau of Reclamation (USBR) | January 1st, 1975

Environmental Characteristics of Select Managed Ponds in the Sacramento–San Joaquin Delta: Implications for Native Fish Conservation and Research

U.S. Geological Survey (USGS) | July 23rd, 2025

The use of wetlands to support native fish research and conservation efforts in the Sacramento–San Joaquin Delta (Delta) of California is a growing priority. The purpos

The use of wetlands to support native fish research and conservation efforts in the Sacramento–San Joaquin Delta (Delta) of California is a growing priority. The purpose of our study was to examine the physiochemical and biological characteristics of select managed ponds in the Delta to determine if they would be suitable habitats for research involving the conservation of delta smelt (Hypomesus transpacificus). We studied 10 managed ponds distributed across the central part of the Delta situated on Bacon Island and Bouldin Island in San Joaquin County, and Holland Tract and Webb Tract islands in Contra Costa County. The managed ponds had a diversity of physical habitat configurations and were not directly connected to waterways surrounding the islands and, therefore, not affected by tides. We studied the managed ponds from approximately November 2021 to December 2023 to assess water quality, zooplankton, fish, and pesticide metrics. Water levels in the managed ponds were managed to varying degrees and were mostly independent of climate-driven wet-dry seasonality. Water quality conditions varied among ponds and were independent of geographic location. Overall, mean monthly chlorophyll a concentration ranged from 15 to 57 (mean=30) micrograms per liter (μg/L), dissolved oxygen concentration ranged from 4 to 9 (mean=7) milligrams per liter (mg/L), pH was 8, salinity was 1 practical salinity units (PSU), specific conductance ranged from 1,202 to 1,839 (mean=1,471) microsiemens per centimeter (μS/cm), and turbidity ranged from 13 to 24 (mean=19) Formazin Nephelometric Units (FNU). Water temperature thresholds that contribute to stress (21 degrees Celsius [°C]) and mortality (28 °C) of delta smelt were often exceeded during summer and fall, though vertical stratification contributed to lower bottom temperatures in the deepest managed ponds, which could potentially provide thermal refugia for delta smelt so long as dissolved oxygen concentrations are suitable. Zooplankton populations were broadly similar among managed ponds and included calanoid and cyclopoid copepods that would be suitable prey for delta smelt. Overall average total zooplankton biomass, as measured with a Schindler-Patalas trap, was 0.6 μg/L (min=0, max=63.6) and peaked during spring at more than 4 μg/L. Fish populations highly varied among the managed ponds with potential predators of delta smelt such as largemouth bass (Micropterus salmoides) and black crappie (Pomoxis nigromaculatus) present in several of the managed ponds; predator distribution among ponds seemed to have been driven primarily by deliberate stocking to facilitate local fisheries. Measured pesticide concentrations were below U.S. Environmental Protection Agency Aquatic Life Benchmarks except for exceedances of three compounds (diuron [herbicide], clothianidin [insecticide], and deltamethrin [pyrethroid insecticide]) in samples collected from ponds on Bouldin Island and Webb Tract. Overall, most managed ponds seemed suitable to support delta smelt, though physical control of potential predators and summer temperature might be needed. The results provide guidance on how to engineer and manage new managed ponds to support research and conservation efforts for delta smelt and other native fishes.

Environmental flow limits to global groundwater pumping

Nature Portfolio (Springer Nature) | October 2nd, 2019

Groundwater is the world’s largest freshwater resource and is critically important for irrigation, and hence for global food security. Already, unsustainable groundwa

Groundwater is the world’s largest freshwater resource and is critically important for irrigation, and hence for global food security. Already, unsustainable groundwater pumping exceeds recharge from precipitation and rivers, leading to substantial drops in the levels of groundwater and losses of groundwater from its storage, especially in intensively irrigated regions. When groundwater levels drop, discharges from groundwater to streams decline, reverse in direction or even stop completely, thereby decreasing streamflow, with potentially devastating effects on aquatic ecosystems. Here we link declines in the levels of groundwater that result from groundwater pumping to decreases in streamflow globally, and estimate where and when environmentally critical streamflows—which are required to maintain healthy ecosystems—will no longer be sustained. We estimate that, by 2050, environmental flow limits will be reached for approximately 42 to 79 per cent of the watersheds in which there is groundwater pumping worldwide, and that this will generally occur before substantial losses in groundwater storage are experienced. Only a small decline in groundwater level is needed to affect streamflow, making our  estimates uncertain for streams near a transition to reversed groundwater discharge. However, for many areas, groundwater pumping rates are high and environmental flow limits are known to be severely exceeded. Compared to surface-water use, the effects of groundwater pumping are markedly delayed. Our results thus reveal the current and future environmental legacy of groundwater use.

Environmental Health Risks from Abandoned Mines in the Sierra Nevada

Sierra Fund | June 9th, 2014

The widespread pollution from Gold Rush mining activities, including mercury, arsenic and lead, constitutes the oldest and longest neglected environmental justice problem

The widespread pollution from Gold Rush mining activities, including mercury, arsenic and lead, constitutes the oldest and longest neglected environmental justice problem in California. The effects of this pollution on human health and the environment are only now beginning to be addressed. Today, the effects of historic mining pollution are an invisible but very real threat to people who live, work or recreate in the Sierra Nevada. Toxins of concern include mercury, arsenic, lead and asbestos.  There is little information about these potential exposures available to Sierra residents. State-issued fish consumption advisories in the region do not provide site-specific advice for many locations people fish, or the species people eat. In 2006, The Sierra Fund, in partnership with California State University Chico, conducted a survey of Sierra clinics. This study found that not one of 13 surveyed clinics included information on mercury in fish as part of their maternal/infant health programs, whether caught locally or not. Additionally, the study learned that none of the clinics surveyed administer an environmental health history form, so it is difficult to connect current health problems to environmental exposures. In order to address this lack of information and provide a springboard for more research, The Sierra Fund conducted three pilot studies of potential environmental exposures in 2009 and 2010 and a pilot outreach program to present these findings to Sierra communities in 2013-14. This report summarizes findings and recommendations from these efforts, in order to encourage continued research into these potentially serious health exposures.

Environmental Impact Report/Environmental Impact Statement (EIR/EIS) for the Cadiz Groundwater Storage Dry-Year Supply Program

Bureau of Land Management (BLM) | September 13th, 2001

In February 1999, Metropolitan issued a Notice of Preparation of an EIR for the Cadiz Project which would be constructed and operated by Metropolitan in the Cadiz and Fe

In February 1999, Metropolitan issued a Notice of Preparation of an EIR for the Cadiz Project which would be constructed and operated by Metropolitan in the Cadiz and Fenner Valleys of the eastern Mojave Desert, San Bernardino County, California. The BLM determined that an EIS would be required as the proposed action includes an amendment of the CDCA Plan for an exception to the utility corridor requirements and grant(s) of right-of-way across federal lands. The BLM issued a Notice of Intent to Prepare an EIS for the proposed action in March 1999. In May 1999, the BLM issued a Notice of Public Meeting and extension of the scoping comment period. The Draft EIR/EIS was published in November 1999 with a 104-day public review period that ended in March 2000. Because numerous comments raised questions regarding groundwater management issues, a Supplement to the Draft EIR/EIS was prepared to provide additional information and to present the Groundwater Monitoring and Management Plan (Management Plan) that has been incorporated into the proposed project. The Management Plan will govern the water storage and extraction operations in the affected groundwater basins to ensure that project operations will not result in any unacceptable adverse impacts to groundwater resources or air quality. The Supplement to the Draft EIR/EIS was circulated for an 80-day public review period that ended in January 2001. The Cadiz Project is proposed by Metropolitan who is acting in partnership with the private company Cadiz Inc. The project will involve construction and operation of a 35-mile pipeline for conveying water between the Iron Mountain Pumping Plant on the Colorado River Aqueduct and the Cadiz/Fenner area, a Cadiz Pumping Plant at Metropolitan.s existing Iron Mountain Pumping Plant facility, 390 acres of spreading basins for percolation of Colorado River water into the groundwater basin in the Cadiz/Fenner area, a wellfield for extracting stored Colorado River water and indigenous groundwater, and associated power poles and line along the conveyance pipeline and in the wellfield. This Final EIR/EIS contains comments received on the Draft EIR/EIS and the Supplement to the Draft EIR/EIS, detailed responses to those comments, and integrates the information contained in the Draft EIR/EIS and Supplement to the Draft EIR/EIS with revisions as appropriate in response to comments.

Environmental justice and drinking water quality: are there socioeconomic disparities in nitrate levels in U.S. drinking water?

Springer Nature | January 17th, 2019

Environmental Justice in California Government

State of California | October 1st, 2003

In California, we have spent over a century and billions of dollars to preserve and protect the environment for current and future generations. The EJ movement asks us to

In California, we have spent over a century and billions of dollars to preserve and protect the environment for current and future generations. The EJ movement asks us to put real people in that environment, particularly the most vulnerable populations such as ethnic minorities, low-income persons, the young and the elderly. In a nutshell, EJ can be said to be the vision and process of creating socially just, sustainable human and ecological systems, where all participate fully in decisions affecting their lives. The Governor’s Office of Planning & Research (OPR) assists the Governor and the Administration in land use planning, research, liaison with local government, small business advocacy, rural policy, and various interagency taskforces. 1999 legislation defined EJ in California law and also established OPR as the coordinating agency in state government for environmental justice (EJ) efforts. The placement of the central EJ program within OPR demonstrates the Legislature’s understanding that EJ efforts require coordination at the highest level of state government.  Indeed, California is the only state that has placed its EJ effort within the Chief Executive’s Office. The legislation establishing OPR as the “coordinating agency in state government for environmental justice programs” (California Government Code § 65040.12) directs the OPR director to consult with state agencies and interested members of the public and private sectors in this state, coordinate its efforts and share information regarding EJ programs with federal agencies, and review and evaluate any information from federal agencies that is obtained as a result of their respective regulatory activities. This policy report is intended to provide a brief history of EJ, report on the status of OPR's efforts, and provide an outline of EJ findings, goals and policies for future EJ efforts within state government. Much work remains to ensure that the most vulnerable of Californians, including people of color and low-income persons, are treated with dignity and respect regarding environmental decisions. OPR views its work thus far as a modest, although significant beginning.

Environmental Justice in California State Government

Governor's Office of Planning and Research (OPR) | November 5th, 2003

In California, we have spent over a century and billions of dollars to preserve and protect the environment for current and future generations. The EJ movement asks us to

In California, we have spent over a century and billions of dollars to preserve and protect the environment for current and future generations. The EJ movement asks us to put real people in that environment, particularly the most vulnerable populations such as ethnic minorities, low-income persons, the young and the elderly. In a nutshell, EJ can be said to be the vision and process of creating socially just, sustainable human and ecological systems, where all participate fully in decisions affecting their lives. The Governor’s Office of Planning & Research (OPR) assists the Governor and the Administration in land use planning, research, liaison with local government, small business advocacy, rural policy, and various interagency taskforces. 1999 legislation defined EJ in California law and also established OPR as the coordinating agency in state government for environmental justice (EJ) efforts. The placement of the central EJ program within OPR demonstrates the Legislature’s understanding that EJ efforts require coordination at the highest level of state government. Indeed, California is the only state that has placed its EJ effort within the Chief Executive’s Office. The legislation establishing OPR as the “coordinating agency in state government for environmental justice programs” (California Government Code § 65040.12) directs the OPR director to consult with state agencies and interested members of the public and private sectors in this state, coordinate its efforts and share information regarding EJ programs with federal agencies, and review and evaluate any information from federal agencies that is obtained as a result of their respective regulatory activities. This policy report is intended to provide a brief history of EJ, report on the status of OPR's efforts, and provide an outline of EJ findings, goals and policies for future EJ efforts within state government. Much work remains to ensure that the most vulnerable of Californians, including people of color and low-income persons, are treated with dignity and respect regarding environmental decisions. OPR views its work thus far as a modest, although significant beginning.