Shop – California Water Library

Page

Showing
31-35 of 35

Per Page

Sort By

San Francisco Bay Nutrient Management Strategy Observation Program

San Francisco Estuary Institute (SFEI) | July 1st, 2020

Summary

This document presents a planning-level description of the draft Nutrient Management Strategy Observation Program (NMSOP), including estimated budget and approach for ph

This document presents a planning-level description of the draft Nutrient Management Strategy Observation Program (NMSOP), including estimated budget and approach for phased growth. The NMSOP represents the design that is needed to address NMS†data needs¨ not an existing program. The proposed design represents a balance between two key goals: ● Target high priority NMS data collection needs ● Where feasible, align field work and data collection efforts with other programs’ established infrastructure, to enhance cost-effectiveness and sustainability. While an inter-program collaborative approach is important for securing NMSOP’s long-term sustainability, building a reliable consortium will require up-front effort to establish inter-program science, management, and financial agreements. This document focuses on the NMSOP scientific program design and growth, with institutional program development described in a companion work plan (SFEI 2016b).

View Document Download Now Email

Synthesis of Data from High-Frequency Nutrient and Associated Biogeochemical Monitoring for the Sacramento– San Joaquin Delta, Northern California

U.S. Geological Survey (USGS) | July 11th, 2017

Summary

This report is the second in a series of three reports that provide information about high-frequency (HF) nutrient and biogeochemical monitoring in the Sacramento–San J

This report is the second in a series of three reports that provide information about high-frequency (HF) nutrient and biogeochemical monitoring in the Sacramento–San Joaquin Delta of northern California (Delta). The purpose of this report is to synthesize the data available from a nutrient and water-quality HF (about every 15 minutes) monitoring network operated by the U.S. Geological Survey in the northern Delta. In this report, we describe the network and focus on the purpose of each station. We then present and discuss the available data, at various timescales—first at the monthly, seasonal, and inter-annual timescales, and second, for comparison, at the tidal and event timescales. As expected, we determined that there is substantial variability in nitrate-N concentrations at short timescales within hours, but also significant variability at longer timescales such as months or years. Resolving this variability is made possible by the HF data, with the largest variability caused by storms, tides, and diel biological processes. Given this large temporal variability, calculations of cumulative nutrient fluxes (for example, daily, monthly, or annual loads) is difficult without HF data. For example, in the Cache Slough, calculation of the annual load without the tidal variability resulted in a 30 percent underestimation of the true annual load value. We conclude that HF measurements are important for accurate determination of fluxes and loads in tidal environments, but, more importantly, provide important insights into processes and rates of nutrient cycling. This report, along with the other two reports of this series (Bergamaschi and others, 2017; Kraus, Bergamaschi, and others, 2017), was drafted in cooperation with the Delta Regional Monitoring Program to help scientists, managers, and planners understand how HF data improve our understanding of nutrient sources and sinks, drivers, and effects in the Delta.

View Document Download Now Email

Technical Approach to Develop Nutrient Numeric Endpoints for California

California State Water Resources Control Board (SWRCB) | July 31st, 2006

Summary

This report provides an approach for the development of nutrient (nitrogen and phosphorus) numeric endpoints for use in the water quality programs of the California’s S

This report provides an approach for the development of nutrient (nitrogen and phosphorus) numeric endpoints for use in the water quality programs of the California’s State Water Resources Control Board (State Water Board) and Regional Water Quality Control Boards (Regional Water Boards). The approach provides a methodology to support several water quality program components including: setting numeric limits for National Pollutant Discharge Elimination System (NPDES) permits; development of Total Maximum Daily Load (TMDL) nutrient numeric endpoints; and for those Regional Water Boards that choose to, the development of numeric nutrient criteria. Guidance for this technical report comes from participants at workshop (Nutrient Numeric Endpoints Training Workshop held on May 18 & 19 2005 in Sacramento, CA) that is a part of a longer running process that has been sponsored by EPA Region IX and the State Water Board. The workshop summary (Summary of May 18-19, 2005 Nutrient Workshop) of this workshop can be downloaded from the project website: http://rd.tetratech.com/epa/. The CA Nutrient Numeric Endpoints process includes a Regional Technical Advisory Group (RTAG); and a collaborative forum of Regional Water Boards, Tribes, and other state and federal agencies in the State Regional Technical Advisory Group (STRTAG). The result of the RTAG / STRTAG process is an approach that has achieved a high level of consensus among participants. The purpose of this document is to describe the approach that has been reviewed and approved by the STRTAG. The intention of the proposed approach is to select nutrient response indicators that can be used to evaluate risk of use impairment, rather than using pre-defined nutrient limits that may or may not result in eutrophication for a particular water body. The report provides a description of the proposed approach that includes innovative elements such as: A water body classification framework that uses three Beneficial Use risk classification categories; Risk-based secondary indicators that are more closely linked to Beneficial Use condition than water column nutrient concentrations; and Modeling tools that provide the necessary linkage analysis between secondary indicators and water column nutrient concentrations. The modeling tools also account for site-specific cofactors such as flow, light availability, and others. This report provides the starting point for a process that will lead to refinements in the classification framework, secondary indicators, and linkage analysis modeling tools through the development of site-specific endpoints. The report has been reviewed by workshop participants; other State, Federal, and Tribal staff; and the Technical Evaluation Committee identified in Appendix 1. This report includes changes made in response to comments received. As an adaptive management process technical updates will be made and new dated editions of this document will be made available. A potential outcome of this process is the adoption of the framework and endpoints by various Regional Water Quality Control Boards for use as nutrient numeric criteria.

View Document Download Now Email

Technical Approach To Develop Nutrient Numeric Endpoints For California Estuaries

California State Water Resources Control Board (SWRCB) | November 20th, 2007

Summary

Eutrophication is one of the top three leading causes of impairments of the nation’s waters, with demonstrated links between anthropogenic changes in watersheds, increa

Eutrophication is one of the top three leading causes of impairments of the nation’s waters, with demonstrated links between anthropogenic changes in watersheds, increased nutrient loading to coastal waters, harmful algal blooms, hypoxia, and impacts on aquatic food webs. These ecological impacts of eutrophication of coastal areas can have far-reaching consequences, including lowered fishery production, loss or degradation of seagrass and kelp beds, smothering of benthic organisms, nuisance odors, and impacts on human and marine mammal health. These modifications have significant economic and social costs. In California, the impacts of nutrient loading on estuaries and coastal waters have not been wel lmonitored. Without management actions to reduce anthropogenic nutrient loads, symptoms are expected to develop or worsen in the majority of systems, due to projected population increases in coastal areas. The purpose for this report is to outline a conceptual framework for the development of nutrient numeric endpoints (NNE) for estuaries and to highlight data gaps and research recommendations critical for their development. The purpose of NNEs for California estuaries is to provide a scientifically defensible framework that can serve as guidance for adopting regulatory numeric criteria. This framework is founded on an evaluation of risk relative to designated beneficial uses. The objective is to control excess nutrient loads to levels such that the risk of impairing the designated uses is minimized. If the nutrients present–regardless of actual magnitude–have a low probability of impairing uses, then water quality standards can be considered to be met. The ultimate goal of this effort is to develop a set of tools that can be used to support the water quality programs of the California State Water Resources Control Board (SWRCB), Regional Water Quality Control Boards and the regulated community. To reach this goal, we envision the development of a set of estuarine NNE tools, including 1) a classification scheme that groups estuaries according to factors that control their biological response to nutrient loading, 2) risk-based indicators of biological response that can provide quantitative measures of the status of beneficial uses relative to nutrient loads; 3) thresholds that define beneficial use risk categories (BURCs), which provides a framework for regulatory decisions based on quantitative assessments of impairment; and 4) modeling tools that link biological response indicators to watershed nutrient loads. To develop a NNE toolkit for estuaries, the first step in this process was to provide a working framework and to identify key data gaps and research recommendations critical for NNE development. The NNE conceptual framework for estuaries is based on previous work by the SWRCB and US EPA Region IX, which provided guidance for development of NNE in streams and lakes (TetraTech 2005). This framework is founded on the concept that biological response indicators are better suited to evaluate the risk of beneficial use impairment, rather than using pre-defined nutrient limits that may or may not result in mitigation of eutrophication for a particular water body. The advantage of the proposed approach is a more robust link to actual impairment of use, rather than an approach that relies on concentration data alone. The California NNE framework for estuaries is based on three organizing principals: • Biological response indicators provide a more direct risk-based linkage to beneficial uses than nutrient concentrations alone. • A weight of evidence approach with multiple indicators will produce NNE with greater scientific validity. • For many of the biological indicators associated with nutrients, no clear scientific consensus exists on a target threshold that results in impairment.

View Document Download Now Email

The Development of Nutrient Criteria for Ecoregions within: California, Arizona, and Nevada

U.S. Environmental Protection Agency (EPA) | January 1st, 2002

Summary

Development of regional nutrient criteria is one component of a larger strategy to address water quality problems associated with nutrient over-enrichment and cul

Development of regional nutrient criteria is one component of a larger strategy to address water quality problems associated with nutrient over-enrichment and culturally-induced accelerated rates of eutrophication of waterbodies in the U.S. The U.S. Environmental Protection Agency (EPA) and Department of Agriculture have several active program initiatives to address the nutrient overenrichment problem. These programs address point and nonpoint sources of pollution, evaluate public health impacts from animal feeding operations, conduct research and monitoring to provide data and assessment techniques to better characterize the problem, and have offer nutrient management policies to provide practical support to agricultural operations to reduce the export of nutrients from their lands. The purpose of the regional nutrient criteria development process is to provide numeric targets for the various nutrient management programs that are regionally appropriate by reflecting geographic variations of waterbody response to nutrients. The current nutrient criteria development process for California and EPA Region IX (California, Nevada, Arizona, and Hawaii) started with the publication of the National Strategy for the Development of Regional Nutrient Criteria (EPA 1998) in June 1998.

View Document Download Now Email

← Prev

Page : 4