Fluid migration pathways to groundwater in mature oil fields: Exploring the roles of water injection/production and oil-well integrity in California, USA

Science of The Total Environment (Elsevier) | August 23rd, 2023

Forest Management (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

Forest lands in California, the majority of which are in the middle to high elevation foothills and mountains, produce a diverse array of resources such as water, timber,

Forest lands in California, the majority of which are in the middle to high elevation foothills and mountains, produce a diverse array of resources such as water, timber, native vegetation, fish, wildlife, and livestock, and outdoor recreation. However, the water produced by these forests has economic value that equals or exceeds that of any other forest resource (Krieger 2001; California Department of Forestry and Fire Protection 2003). Most of California’s major rivers and a substantial portion of its runoff originate in these forests; therefore, most of California’s major water development projects are tied strongly to forested watersheds. Forest management activities can affect water quantity and quality. This strategy focuses on forest management activities, on both public and privately-owned forest lands, whose goals specifically include improvement of the availability and quality of water for downstream users.

Fourth Five Year Review Report for the San Gabriel Valley Area 2 Superfund Site, Los Angeles, California

U.S. Environmental Protection Agency (EPA) | September 15th, 2022

This is the fourth Five-Year Review of the San Gabriel Valley Area 2 (Site) located in the San Gabriel Valley in Los Angeles County, California. The purpose of this Five-

This is the fourth Five-Year Review of the San Gabriel Valley Area 2 (Site) located in the San Gabriel Valley in Los Angeles County, California. The purpose of this Five-Year Review is to review information to determine if the remedy is and will continue to be protective of human health and the environment. The Site addresses approximately 10 square miles of groundwater contamination in eastern Los Angeles County within the San Gabriel Valley. Groundwater contamination is believed to result from the cumulative impact of decades of improper chemical handling and disposal practices at numerous industrial operations in the Valley. The Site contamination originates at current and former industrial facilities in and near Azusa, California and extends to the southwest through portions of the cities of Irwindale, Baldwin Park, West Covina, and Industry. The most prevalent contaminants in groundwater are trichloroethylene, tetrachloroethylene, carbon tetrachloride, perchlorate, n-nitrosodimethylamine (NDMA), and 1,4-dioxane.

Fragmented kelp forest canopies retain their ability to alter local seawater chemistry

Nature Portfolio (Springer Nature) | July 20th, 2020

Kelp forests support some of the most productive and diverse ecosystems on Earth, and their ability to uptake dissolved inorganic carbon (DIC) allows them to modify loca

Kelp forests support some of the most productive and diverse ecosystems on Earth, and their ability to uptake dissolved inorganic carbon (DIC) allows them to modify local seawater chemistry, creating gradients in carbon, pH, and oxygen in their vicinity. By taking up both bicarbonate and CO2 as a carbon source for photosynthesis, kelp forests can act as carbon sinks, reducing nearby acidity and increasing dissolved oxygen; creating conditions conducive to calcification. Recent stressors, however, have reduced kelp forest canopies globally; converting once large and persistent forests to fragmented landscapes of small kelp patches. In a two-year study, we determined whether fragmented kelp patches retained the ability to alter local seawater chemistry. We found that diel fluctuations of multiple parameters of carbonate chemistry were greater in the kelp canopy than in the kelp benthos and in adjacent urchin barrens, consistent with metabolic activity by the kelp. Further, kelp fragments increased pH and aragonite saturation and decreased pCO 2 during the day to a similar degree as large, intact kelp forests. We conclude that small kelp patches could mitigate OA stress and serve as spatial and temporal refugia for canopy-dwelling organisms, though this effect is temporary and confined to daylight hours during the growing season.

Framework to Coordinate Water Quality Improvement and Wildlife Habitat Conservation to Protect California Streams, Wetlands and Riparian Areas

San Francisco Estuary Institute (SFEI) | February 1st, 2016

The emergence of comparable landscape approaches to wildlife conservation and water quality improvement through federal and California state regulatory and management pr

The emergence of comparable landscape approaches to wildlife conservation and water quality improvement through federal and California state regulatory and management programs provides an opportunity for their coordination to better protect California’s aquatic resources, especially streams, wetlands, and riparian areas. Such coordination is patently desirable. A framework has been developed to help coordinate restoration and compensatory mitigation across policies governing wildlife conservation and water quality in the landscape context. The framework is based on the Wetland and Riparian Area Monitoring Plan (WRAMP) of the California Wetland Monitoring Workgroup (CWMW) of the Water Quality Monitoring Council. The framework presented here is a version of the standard WRAMP framework. It only differs from the standard framework to better accommodate wildlife conservation planning, assessment and reporting. To distinguish this version from the standard version, it is termed theWRAMP for wildlife (WRAMPw).

Franks Tract Futures

Delta Stewardship Council (Delta Council) | April 26th, 2022

From Sediment to Top Predators: Broad Exposure of Polyhalogenated Carbazoles in San Francisco Bay

American Chemical Society (ACS) | January 23rd, 2017

The present study provides the first comprehensive investigation of polyhalogenated carbazoles (PHCZs) contamination in an aquatic ecosystem. PHCZs have been found in soi

The present study provides the first comprehensive investigation of polyhalogenated carbazoles (PHCZs) contamination in an aquatic ecosystem. PHCZs have been found in soil and aquatic sediment from several different regions, but knowledge of their bioaccumulation and trophodynamics is extremely scarce. This work investigated a suite of 11 PHCZ congeners in San Francisco Bay (United States) sediment and organisms, including bivalves (n = 6 composites), sport fish (n = 12 composites), harbor seal blubber (n = 18), and bird eggs (n = 8 composites). The most detectable congeners included 3,6-dichlorocarbazole (36-CCZ), 3,6-dibromocarbazole (36-BCZ), 1,3,6-tribromocarbazole (136-BCZ), 1,3,6,8-tetrabromocarbazole (1368-BCZ), and 1,8-dibromo-3,6-dichlorocarbazole (18-B-36-CCZ). The median concentrations of ΣPHCZs were 9.3 ng/g dry weight in sediment and ranged from 33.7 to 164 ng/g lipid weight in various species. Biomagnification was observed from fish to harbor seal and was mainly driven by chlorinated carbazoles, particularly 36-CCZ. Congener compositions of PHCZs differed among species, suggesting that individual congeners may be subject to different bioaccumulation or metabolism in species occupying various trophic levels in the studied aquatic system. Toxic equivalent (TEQ) values of PHCZs were determined on the basis of their relative effect potencies (REP) compared to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The median TEQ was 1.2 pg TEQ/g dry weight in sediment and 4.8–19.5 pg TEQ/g lipid weight in biological tissues. Our study demonstrated the broad exposure of PHCZs in San Francisco Bay and their characteristics of bioaccumulation and biomagnification along with dioxin-like effects. These findings raise the need for additional research to better elucidate their sources, environmental behavior, and fate in global environments.

From the Sierra to the Sea: The Ecological History of the San Francisco Bay-Delta Watershed

Bay Institute | January 1st, 1998

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two cent

A vast watershed connects the mountain streams surrounding California’s Central Valley with San Francisco Bay and the ocean beyond. Over the course of the last two centuries, much of the natural productivity, biodiversity and ecological integrity of the watershed has been destroyed by modifying the environment without fully understanding the long-term environmental consequences. Long the site of some of the nation’s most intensive conflicts over the use of land and water resources, this system is now emerging as the focus of one of the most ambitious ecological restoration efforts ever undertaken in the United States. This report was designed to provide a coherent and defensible ecological framework and information base for restoration. The need for such an historical, broad-scale perspective on system ecology stems from two fundamental principles of ecological restoration - the need to manage toward a natural template and to manage at ecosystem and landscape levels.

Frontiers in Ecology and the Environment: Alteration of streamflow magnitudes and potential ecological consequences: a multiregional assessment

Ecological Society of America (Wiley) | October 19th, 2010

Human impacts on watershed hydrology are widespread in the US, but the prevalence and severity of streamflow alteration and its potential ecological consequences have not

Human impacts on watershed hydrology are widespread in the US, but the prevalence and severity of streamflow alteration and its potential ecological consequences have not been quantified on a national scale. We assessed streamflow alteration at 2888 streamflow monitoring sites throughout the conterminous US. The magnitudes of mean annual (1980–2007) minimum and maximum streamflows were found to have been altered in 86% of assessed streams. The occurrence, type, and severity of streamflow alteration differed markedly between arid and wet climates. Biological assessments conducted on a subset of these streams showed that, relative to eight chemical and physical covariates, diminished flow magnitudes were the primary predictors of biological integrity for fish and macroinvertebrate communities. In addition, the likelihood of biological impairment doubled with increasing severity of diminished streamflows. Among streams with diminished flow magnitudes, increasingly common fish and macroinvertebrate taxa possessed traits characteristic of lake or pond habitats, including a preference for fine-grained substrates and slow-moving currents, as well as the ability to temporarily leave the aquatic environment.

Functional Flows in Modified Riverscapes: Hydrographs, Habitats and Opportunities

Oxford University Press (OUP) | August 5th, 2015

Building on previous environmental flow discussions and a growing recognition that hydrogeomorphic processes are inherent in the ecological functionality and biodiversity

Building on previous environmental flow discussions and a growing recognition that hydrogeomorphic processes are inherent in the ecological functionality and biodiversity of riverscapes, we propose a functional-flows approach to managing heavily modified rivers. The approach focuses on retaining specific process-based components of the hydrograph, or functional flows, rather than attempting to mimic the full natural flow regime. Key functional components include wet-season initiation flows, peak magnitude flows, recession flows, dry-season low flows, and interannual variability. We illustrate the importance of each key functional flow using examples from western US rivers with seasonably predictable flow regimes. To maximize the functionality of these flows, connectivity to morphologically diverse overbank areas must be enhanced in both space and time, and consideration must be given to the sediment-transport regime. Finally, we provide guiding principles for developing functional flows or incorporating functional flows into existing environmental flow frameworks.