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Continuous Water Quality Meta Data

I. Contact Information

Lead Contact: Mike Dempsey
Department of Water Resources
Division of Environmental Services
3500 Industrial Blvd, West Sacramento, CA 95691
(916) 376-9775
Email Mike Dempsey

Email Sal Batmanghilich

DWR Bryte Laboratory
1450 Riverbank Road,
West Sacramento, CA 95605
(916) 375-6008

Sid Fong - Supervisor Chem. Test Section
Email Sid Fong

II. Study Mandate and Objectives

The State Water Resources Control Board (SWRCB) sets water quality objectives to protect beneficial uses of water in the Sacramento-San Joaquin Delta and Suisun Bay. These objectives are met by establishing standards mandated in water right permits issued to the Department of Water Resources (DWR) and U.S. Bureau of Reclamation (USBR) by the SWRCB. The standards include minimum Delta outflows, limits to Delta water export by the State Water Project (SWP) and the Central Valley Project (CVP), and maximum allowable salinity levels.

In 1971, the SWRCB established Water Right Decision 1379 (D-1379). This Decision contained new water quality requirements for the San Francisco Bay-Delta Estuary. D-1379 was also the first water right decision to provide terms and conditions for a comprehensive monitoring program to routinely determine water quality conditions and changes in environmental conditions within the estuary. The monitoring program described in D-1379 was developed by the Stanford Research Institute through a contract with the SWRCB. Implementation of the monitoring program began in 1972, as SWRCB, DWR, and USBR met to define their individual responsibilities for various elements of the monitoring program. In 1978, amendments to water quality standards were implemented and resulted in Water Right Decision 1485 (D-1485). More recently these standards were again amended under the 1995 Water Quality Control Plan and Water Right Decision 1641 (D-1641) established in 1999. The SWP and CVP are currently operated to comply with the monitoring and reporting requirements described in D-1641. D-1641 requires DWR and USBR to conduct a comprehensive environmental monitoring program to determine compliance with the water quality standards and also to submit an annual report to SWRCB discussing data collected.

Continuous water quality monitoring is one element of the Environmental Monitoring Program (EMP) conducted by DWR and USBR with assistance from the USGS under the Interagency Ecological Program (IEP) umbrella. The overall objective of the water quality monitoring program is to provide information for water resource management in compliance with flow-related water quality standards set forth in the series of Water Right Decisions described above. These decisions permit the USBR and DWR to appropriate water for operation of the CVP and the SWP. In return, the two agencies are required to monitor the effects of diversions and flow manipulations resulting from project operations and ensure the compliance with existing water quality standards.

III. Study Area and Sample Sites

A. General Information

The study area includes the Delta within its legal boundaries, Suisun Bay and Suisun Marsh. The EMP continuous sampling sites range from Martinez east through the upper Estuary up river to Hood on the Sacramento River and up river to Vernalis on the San Joaquin river. These sites represent the main inflows and outflows of the Sacramento-San Joaquin Delta, and Suisun Bay and Suisun Marsh. In early June, 2015, the California Department of Water Resources installed 10 new monitoring stations that were established for the Emergency Drought Barriers due to four years of drought in California.  As of now, all 10 new stations are funded for another year with most being funded longer term by Division of Environmental Services (DES), Bay Delta office (BDO), etc.   As a result,  the Real-time Section is in charge of the six out of ten pile stations, which are now permanent stations.  These new pile stations are operated under Decision 1641 which is mandated by State Water Resources Control Board (SWRCB) for San Francisco / Sacramento / San Joaquin Delta Estuary (Bay-Delta) Program.

Currently, 15 sites are sampled continuously every 15 minutes throughout the year.

B. Name and Location Information for Continuous Water Quality Sampling Sites

Map of Stations

Description of Both Active and Historic RTM Sites

  • Coordinates are in decimal degrees, Geographic coordinate system, North American Datum 1983 and have been verified to be accurate for 1:24,000 scale mapping.
  • Habitat types are based on ecologically important physical and chemical habitat characteristics.
  • Regions are based on cluster analyses of monthly water quality variables. For specific analyses see Lehman 1996 and Lehman and Smith 1991; Jassby and Cloern 2000.
  • C. Sample Sites' History and Rationale for Monitoring


    • "Rationale-1970" is from the Stanford Research Institute report to the State Water Resources Control Board of 1970.
    • "Rationale-2002" is from the EMP Review of 2001-2002.

    IV. Period of Record

    The first six real-time stations and variables monitored by the EMP were started in 1978 to accommodate compliance monitoring for new water quality standards establish in D-1485. In the early 1990's additional bottom sensors were added to the Martinez, Mallard Island and Antioch stations to better monitor the salinity intrusion developed with the incoming tides. In 1999 one of the continuous multi-variable shore stations (Sacramento River at Hood) was added to replace the USBR long-term site (Sacramento River at Greene's Landing), in the early 2000's two new multi-variable continuous stations San Joaquin river at Prisoner's Point and San Joaquin river at Vernalis were added and four new salinity and temperature stations were added as part of the EMP review. Some sampling stations were moved to a nearby location over time to alleviate access problems or to shift from shore sampling to vessel sampling (or vice versa). In the EMP data base, all moved stations are identified by a modified station name (usually the letter A is added). However, the original station names are generally retained in the successive water right decisions specifying monitoring requirements for the EMP.

    V. Sampling Frequency

    From 1978 to the later part of 2008 water samples were acquired hourly with meteorological variables sampled every 15 minutes. Since 2008 all variables are sample every 15 minutes .

    VI. Data availability in EMP-CMS's Continuous Water Quality database

    Although water quality data have been collected for some stations since 1968 under various programs, only data gathered by the EMP continuous water quality since 1983 are available in this database.

    VII. Field Methods

    All stations with, the exception of the four mid-channel locations, are service by car every two weeks where the variables are verified with lab calibrated field instruments and cleaned. The mid-channel locations are serviced by boat every two months or sooner if conditions require.

    A. Field measurements

    Calibration Procedures and Frequency: Procedures have been developed for routine testing, maintenance and calibration of the field measurement equipment. Instruments are calibrated to comply with manufacturers or laboratory specifications.
    Accuracy: The maximum deviation allowed for instrument calibration is 3 percent. If a field visit verification indicates significant drift has occurred, data collected prior are flagged as questionable and the instrument is calibrated to specs or replaced. An "Instrument Maintenance, Calibration and Repair" log is maintained for each instrument documenting its condition, scheduled periodic services, the date, and the individual performing the calibration.

    B. Sample Collection

    Chlorophyll samples are generally collected monthly, except when an unusual event triggers a special collection. These samples are analyzed at Bryte lab and the results are used to quantify the fluorescence values generated continuously at the stations.

    Water samples are collected at a depth of approximately 3 feet for surface measurements and approximately 5 feet off the channel bottom for the bottom measurements.

    C. Sample Containers and holding times

    The DWR Bryte laboratory supplies all necessary sampling materials to the EMP field sampling crews. Requirements for sample containers, preservation techniques, and holding times are found in one of the following references (or later editions): Standard Methods for the Examination of Water and Waste Water, American Public Health Association, et al., 19th Edition; Handbook for Sampling and Sample Preservation of Water and Wastewater, EPA 600/4-82-029, September 1982.

    To monitor possible contamination during the collection, transport, and storage of water samples, two field blanks are taken each month (at rotating site locations). Laboratory prepared blank water is processed in the same manner as regular samples including field filtration, addition of preservatives and storage.

    VIII. Laboratory Methods

    Since 1975, all water quality analyses are conducted by staff at the DWR Bryte Laboratory. Located in West Sacramento, its primary function is to analyze drinking water, surface water, groundwater, and wastewater. DWR Bryte lab has maintained certification by the Environmental Protection Agency and the California Department of Health Services for water analysis since 1978. It also provides quality assurance, and related technical services.

    IX. Data Management

    Station visit field measurements are recorded on field data sheets and entered in the site visit module of DWR EMP-CMS database.n. Laboratory analyses are performed by DWR Bryte Laboratory and the results are entered in the FLIMS database at the lab. On a regular basis data from the FLIMS database are loaded into DWR’s Water Data Library (WDL) database. EMP’s laboratory results are sent via Email and stored in a binder to calibrate field Fluorometer data . After reviewing of the results for accuracy and completeness, EMP-CMS’s continuous water quality data are available here.

    X. Reference

    A. Methodological Texts

    1. Bryte Chemical Laboratory Quality Assurance Manual. 2002. Quality Assurance Technical Document 8. Department of Water Resources Publications, Sacramento, California. 48 pp.
    2. Methods for Chemical Analyses of Water and Wastes. 1983. EPA-600/4-79-020
    3. Standard Methods for the Examination of Water and Wastewater. 1992. 19th Edition or later, APHA, American Water Works Association, Water Pollution Control Federation, Washington, D.C.
    4. Methods for Determination of Inorganic Substances in Water and Fluvial Sediments. 1985. Techniques of Water Resources Investigations, USGS, Book 5, Washington, D.C.
    5. Annual Book of American Society for Testing and Materials Standards. 1988. Volumes 11.01 and 11.02, ASTM, Philadelphia, Pennsylvania
    6. Official Methods of Analysis. 1994. 14th Edition, AOAC International, Arlington, Virginia
    7. Methods for Organic Chemical Analysis of Municipal and Industrial Wastes. 1982. EPA 600/4-82-057
    8. Guidelines Establishing Test Procedures for the Analysis of Pollutants Under Clean Water Act. 1984. Federal Register, EPA, 40 CFR, Part 136
    9. Biological Field and Laboratory Methods. 1973. EPA-670/4-73-001
    10. Test Methods for Evaluating Solid Wastes, Physical / Chemical Methods. 1986. EPA, SW846, Volumes 1A, 1B, 1C and II

    B. Reports, Publications and Other Pertinent Literature

    1. Jassby, A. D.; Cloern, J. E.. 2000. Organic matter sources and rehabilitation of the Sacramento-San Joaquin Delta (California, USA). Aquatic Conservation 10 (5): 323-352.
    2. Lehman P. W. and R. W. Smith. 1991. Environmental factors associated with phytoplankton succession for the Sacramento-San Joaquin Delta and Suisun Bay Estuary, California. Est. Coast. Shelf. Sci. 32:105-128.
    3. Lehman, P. W. 1996. Water quality conditions in the Sacramento-San Joaquin Delta, 1970-1993. Environmental Services Office, Department of Water Resources, 3251 S Street, Sacramento CA 95818.
    4. State Water Resources Control Board. 1970. An Environmental Monitoring Program for the Sacramento-San Joaquin Delta and Suisun Bay. Stanford Research Institute. SWRCB Publication No. 40
    5. Triboli, K., Mueller-Solger, A. and Vayssi´┐Żres, M. 2003. The Grind about Sonicated Chlorophyll (or: Did a Method Change in 1998 Affect EMP Chlorophyll Results?) IEP Newsletter, Winter 2003. 16 (4): 13.