Microplastic Monitoring and Science Strategy for San Francisco Bay

San Francisco Estuary Institute (SFEI) | February 1st, 2017

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducted a

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducted a special study to measure microplastic in treated wastewater effluent and Bay surface water. Bay surface water appeared to have higher microplastic levels than other urban water bodies sampled in North America, such as the Great Lakes and Chesapeake Bay. Microbeads derived from personal care products and tiny fibers, a portion of which were likely derived from synthetic clothing, were recovered from all nine Bay sites. Tiny particles, primarily fibers, were also detected in treated effluent from Bay Area facilities; not all of these particles are known to be plastic. These findings received considerable media attention and catalyzed state and federal policy shifts. 

Microplastic Monitoring and Science Strategy for the San Francisco Bay

San Francisco Estuary Institute (SFEI) | February 7th, 2017

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducte

Microplastic is commonly defined as plastic particles smaller than 5 mm. In 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) conducted a special study to measure microplastic in treated wastewater effluent and Bay surface water. Bay surface water appeared to have higher microplastic levels than other urban water bodies sampled in North America, such as the Great Lakes and Chesapeake Bay. Microbeads derived from personal care products and tiny fibers, a portion of which were likely derived from synthetic clothing, were recovered from all nine Bay sites. Tiny particles, primarily fibers, were also detected in treated effluent from Bay Area facilities; not all of these particles are known to be plastic. These findings received considerable media attention and catalyzed state and federal policy shifts. In 2016, the RMP authorized a special study to develop a strategy for continued study of microplastic in San Francisco Bay. To form this strategy, the RMP convened stakeholders to articulate management questions specific to microplastic pollution, and then conducted a one-day workshop that brought together stakeholders and microplastic experts to develop an understanding of the state of the science on this emerging contaminant, and determine consensus priorities for future work. The resulting strategy document provides: • an overview of microplastic science relevant to San Francisco Bay, • the management questions that will guide future work, • a summary of available sampling and analysis methods, and • a multi-year plan for studies that would provide answers to the management questions. The monitoring and management of both macro- and microplastic are issues that extend beyond the scope of the RMP. In this document, we seek to identify data gaps, next steps, and strategic partners who can help provide information and resources to inform management decisions. This Microplastic Strategy will be refined and adjusted in years to come based on advances in understanding and changes in the sources and management of plastic pollution.

Microplastic Strategy Update on behalf of the Regional Monitoring Program (RMP) for Water Quality in San Francisco Bay

San Francisco Estuary Institute (SFEI) | December 2nd, 2019

Based on the detection of microplastics in San Francisco Bay surface water and Bay Area wastewater effluent in 2015, the Regional Monitoring Program for Water Quality in

Based on the detection of microplastics in San Francisco Bay surface water and Bay Area wastewater effluent in 2015, the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) convened a Microplastic Workgroup (MPWG) in 2016 to discuss the issue, identify management information needs and management questions (MQs), and prioritize studies to provide information to answer these management questions. The MPWG meets annually to review on-going microplastic projects and to conduct strategic long-term planning in response to new information in this rapidly evolving field.

Microplastics from Tire Particles in San Francisco Bay

San Francisco Estuary Institute (SFEI) | March 14th, 2022

Microplastics in Lake Mead National Recreation Area

U.S. Geological Survey (USGS) | October 9th, 2019

  This dataset describes the quantity and morphology of microplastics in water, surficial sediment, sediment core, fish, and shellfish samples from Lake Mead Nation

  This dataset describes the quantity and morphology of microplastics in water, surficial sediment, sediment core, fish, and shellfish samples from Lake Mead National Recreation Area (Nevada/Arizona). Water and surficial sediment samples were collected once at 9 locations. A sediment core (33 cm long) was extracted from Las Vegas Bay to assess changes in microplastic deposition over time. Striped bass (Morone saxatilis), common carp (Cyprinus carpio), quagga mussels (Dreissena bugensis), and Asian clams (Corbicula fluminea) were sampled at a subset of locations to assess biological uptake of microplastics. Sampling and analysis methods are described in the Processing Steps section of the metadata. All samples were collected in March 2017 except the sediment core, which was collected in March 2018.  

Middle Santa Ana River Watershed TMDL Task Force

Santa Ana Watershed Project Authority (SAWPA) | July 5th, 2018

The Task Force is an 18-agency collaborative effort organized by the Santa Ana Watershed Project Authority. It was formed in January 2006 to coordinate water quality impr

The Task Force is an 18-agency collaborative effort organized by the Santa Ana Watershed Project Authority. It was formed in January 2006 to coordinate water quality improvement activities related to bacteria in the Middle Santa Ana River Watershed. The activities were designed to manage or eliminate sources of bacterial indicators in local waterbodies. The Task Force supports on-going source investigation efforts to identify major sources of bacterial indicators and to understand how to best address them. Task Force resources are allocated on a risk-reduction priority basis in order to achieve compliance where it will provide the greatest improvement in public health.

Modeling the dynamic penetration depth of post-1950s water in unconfined aquifers using environmental tracers: Central Valley, California

Journal of Hydrology (Elsevier) | December 5th, 2022

The penetration depth of post-1950s recharge (D-1950) in aquifers is a marker that is frequently used to identify groundwater that is susceptible to anthropogenic contami

The penetration depth of post-1950s recharge (D-1950) in aquifers is a marker that is frequently used to identify groundwater that is susceptible to anthropogenic contamination. Here, we compute D-1950 values at wells, interpolate them in space, and project them across time to map the moving front of modern recharge in four dimensions in the Central Valley aquifer system, California, USA. Tracers of groundwater age (tritium, carbon-14, noble gases, sulfur hexafluoride, and chlorofluorocarbons) were collected at 650 wells spatially distributed throughout the Central Valley and were fit to a lumped-parameter model that assumes a logarithmic age-depth profile in the aquifer. For samples where tritium was present (>0.3 tritium units), the model was used to predict D-1950 at wells screened above or across the modern-premodern interface (n = 484). Wells with samples where tritium was absent (≤0.3 tritium units) were used to define the depth beyond which groundwater is completely premodern (n = 166). Predicted D-1950 values were below the depth of screen bottoms for wells where groundwater is completely modern, and above the depth of screen tops for wells where groundwater is completely premodern. The interpolated surface of D-1950 is dynamic, less prone to extreme values, and produces maps with lower interpolation errors due to a higher spatial density of wells than maps based on the depth of premodern groundwater. Between 2005 and 2025, D-1950 is expected to deepen by 11 and 12 m in the northern and southern parts of the Central Valley, respectively. Areas where D-1950 increases rapidly are likely to see increases in nitrate and other anthropogenic contaminants associated with the downward moving front of modern water.

Monitoring for Acidification Threats in West Coast Estuaries: A San Francisco Bay Case Study

San Francisco Estuary Institute (SFEI) | June 6th, 2017

The estuaries of the U.S. Pacific Coast are diverse and productive ecosystems of high ecological, cultural, and economic value. They have many stakeholders, are managed t

The estuaries of the U.S. Pacific Coast are diverse and productive ecosystems of high ecological, cultural, and economic value. They have many stakeholders, are managed to meet many different, often competing, objectives, and contend with environmental stressors from a variety of sources. Ocean acidification (OA) is one stressor expected to have widespread impacts on the Pacific coastal ecosystems. Recently, the West Coast Ocean Acidification & Hypoxia Science Panel recommended improved monitoring to assess biological impacts in the coastal ocean and estuaries. However, the current status and impacts of ocean acidification on West Coast estuaries are largely unknown. A workshop in October 2016 brought together scientists from throughout the West Coast of the United States, leading researchers on San Francisco Bay, the region’s largest estuary, and representatives from a variety of management agencies. The main objectives of the Workshop were to assess whether acidification is of concern in the Bay and to identify its potential impacts to beneficial uses, cost-effective monitoring strategies, and potential management actions. Although the Bay was the case study, the aim was to develop general guidance that could be applied to West Coast estuaries.

Monitoring Program for the Santa Maria Valley Management Area

California Department of Water Resources (DWR) | April 11th, 2013

The terms and conditions of a Stipulation in the Santa Maria Valley Groundwater Basin Litigation passed down by the Superior Court of the State of California, County of

The terms and conditions of a Stipulation in the Santa Maria Valley Groundwater Basin Litigation passed down by the Superior Court of the State of California, County of Santa Clara, on June 30, 2005, are intended to “impose a physical solution establishing a legal and practical means for ensuring the Basin’s long-term sustainability.” Under the Stipulation, the groundwater, imported and developed water, and storage space of the Basin are to be managed in three management areas, including one for the Santa Maria Valley (SMVMA) (Figure 1). The management area is approximately 175 square miles in size encompassing the Santa Maria and Sisquoc Valleys, extending north to the Nipomo Mesa, east to the cliffs above the Santa Maria River and terraces along the Sisquoc River, south to the Casmalia and Solomon Hills, and west to the coast. According to the Stipulation, a monitoring program is to be established for each of the three management areas to collect and analyze data regarding water supply and demand such that the following objectives are met: 1) assessment of groundwater conditions, both levels and quality; 2) determination of land use, water requirements, and water supply; and 3) accounting of amounts and methods of disposition of water utilized. This monitoring program has been prepared to meet these objectives in the SMVMA. Also in accordance with the Stipulation, it is expected that the monitoring results will be utilized for preparation of annual reports on the SMVMA, including an assessment of whether conditions of severe water shortage are present. The monitoring program for the SMVMA, with minor revisions from October 2008, is described by individual element in the following section. Among other components, the monitoring program includes networks of historically monitored wells, stream gauges, and climatic stations. These monitoring points were selected based on publicly available information about their locations, characteristics, and historical data records with the intent of continuing those records as much as possible. It is recognized that, as implementation of the program proceeds, the inclusion of some network wells may be determined to be impractical or impossible due to problems of access or abandonment. Further, the reestablishment of inactive (or installation of new) wells, stream gauges and climatic stations will depend on interagency coordination, permitting procedures, and budgetary constraints. Thus, it is anticipated that the overall monitoring program will be incrementally implemented as practicalities like those mentioned above dictate. Similarly, it is expected that, with time, the program will undergo modification in response to various factors (e.g. replacing network wells abandoned in the future, revising well classifications by aquifer depth zone), while maintaining the overall goal of facilitating interpretation and reporting on water requirements, water supplies, and the state of groundwater conditions in the SMVMA.

Monitoring Special Study (MSS) Salinity Point Source and Ion Sampling CY 2022–2023

California Department of Water Resources (DWR) | August 15th, 2022

The interior southern Delta region of the San Francisco Estuary (SFE) has relatively higher seasonal-based salinity compared to other interior freshwater regions. Some of

The interior southern Delta region of the San Francisco Estuary (SFE) has relatively higher seasonal-based salinity compared to other interior freshwater regions. Some of this degradation in water quality in the interior southern Delta likely originates in upstream salt loading from agriculture drainage in the San Joaquin River prior to reaching the channels of Old River and Grant Line Canal. However, there is also measurable increases in salt loading within the channel networks of Old River at Head (OH1) east to lower Old River near Mountain House Creek (ORM) and the interconnected sloughs of Paradise and Sugar Cut in the region of Doughty Cut (Figure 1) (in-Delta agriculture drainage), as well as other naturally occurring (i.e., groundwater) sources and other non-point and point sources. The California Department of Water Resources (DWR) and U.S. Bureau of Reclamation (Reclamation), under the State Water Resources Control Board’s (State Water Board) Water Right Decision 1641 (D-1641), are assigned partial responsibility for meeting interior southern Delta water quality objectives each year at multiple compliance stations that measure specific conductance (EC) data continuously at 15-minute intervals.