Department of Water Resources Home

Grab Sample Data Information

Grab Sample Data from State Water Project (SWP) Radioactivity Monitoring

The Division of Operations and Maintenance’s (O&M) Water Quality Section conducts quarterly monitoring of raw SWP surface water for radionuclides per Title 22 California Code of Regulations (22 CCR), §64442. Monitoring occurs at three SWP locations: Banks Headworks, Check 13, and Check 41. We continue to monitor quarterly even though 22 CCR, §64442(d)(4)(A) allows us to conduct less frequent sampling (i.e., once every 9 years) because our results for Gross Alpha are below the 3pCi/L detection level for purposes of reporting (DLR). Samples from February, May, August, and November are analyzed for Gross Alpha and Gross Beta per method SM 7110B, Potassium 40 per method EPA 901.1, and Tritium per EPA 906.0. Quarterly routine radionuclide sampling per 22 CCR, §64442 is beneficial to the State Water Contractors and the public and is an example of our commitment to monitoring water quality in the SWP.

SWP radioactivity monitoring results are as follows:

Our 2015 average Gross Alpha sample results are:

  • Banks (KA000331) = 2.56 pCi/L
  • Check 13 (KA007089) = 2.28 pCi/L
  • Check 41 (KA030341) = 1.89 pCi/L

Our 2015 average Gross Beta sample results are:

  • Banks (KA000331) = 2.19 pCi/L
  • Check 13 (KA007089) = 2.21 pCi/L
  • Check 41 (KA030341) = 1.97 pCi/L

Our 2015 average Potassium 40 sample results are:

  • Banks (KA000331) = 53.3 pCi/L
  • Check 13 (KA007089) = 61.7 pCi/L
  • Check 41 (KA030341) = 56.7 pCi/L

Our 2015 average Tritium sample results are:

  • Banks (KA000331) = 247 pCi/L
  • Check 13 (KA007089) = 250 pCi/L
  • Check 41 (KA030341) = 254 pCi/L

O&M’s Water Quality Section does not monitor the SWP water for radionuclides per 22 CCR, §64443 because the CA Department of Public Health (CDPH) has not informed us that the SWP is a “vulnerable system,” but Gross Beta and Potassium 40 (naturally occurring) are monitored in case we are ever notified by CDPH that the SWP is vulnerable.

Grab Sample Data Reports

The O&M Field Divisions maintain more than 30 standard grab sampling stations along the SWP. These sampling sites are routinely monitored according to this sampling schedule.

The O&M Water Quality Section prepares monthly Project Summary tables of important grab sample chemicals at key SWP locations.

Pesticide data for key SWP locations are generally available for the months of March, June, and September. Pesticide data are not available for September 2016. Pesticide Summary tables are prepared that report all detected pesticide values. Refer to the document entitled Analytical Methods for Organic Chemicals for a complete listing of all organic chemicals included in the laboratory analyses.

Grab Sample Data from Station Groups in the Water Data Library

Station Groups are a quick way to find results in the Water Data Library (WDL) for a collection of sampling locations. Use the links below to quickly retrieve O&M grab sample data from the WDL.

DWR Publications

Other O&M water quality reports may be found on the DWR Publicatons web page using the link to "Publications & Video Repository." Choose the "State Water Project" topic and then choose the "Water Quality" topic for a listing of publications.

For other parameters or reports, Contact Us.