State Water Project – Water Quality Data


Nearly all of the surface water entering the District is conveyed through the California Aqueduct of the State Water Project (SWP). Use the links below to obtain SWP water quality data. Note that water quality can vary significantly from month to month and year to year. For example, electrical conductivity (EC) which is related to salt content, is lower in spring than in the fall and lower in wet water years than dry water years. The Engineering Department can provide assistance upon request.

General Minerals, General Characteristics and Metals

 About once per month, the DWR collects grab samples from various points on the Aqueduct. These are analyzed by Bryte Chemical Laboratory for general minerals, general physical characteristics and metals. The closest sampling point and the one most reflective of District water quality is located at DWR’s Teerink Pumping Plant. The Teerink Pumping Plant is located roughly 4.5 miles downstream from Maricopa Highway and 2 miles upstream from the WRM 10 Pumping Plant.

  1. Click on link below:  
    1. Change the “Search By” to “Station Group”
    2. Next use the drop down menu, find “O&M CA Aqueduct Grab Sample Data”, then click “Search”
    3. Then at the top, select Specific Analytes or Analyte Group 4. Then check on “Teerink Pumping Plant”, Which is 7th station down from the top of the list.
    4. Then click, “Get Data”


Coli form Bacteria and E. coli

Once per week, the District collects a water sample at its headquarters on Highway 166 to help provide an indication of the amount of coliform bacteria in the California Aqueduct. These samples are only representative of one arbitrary point in the District’s WRM 8 system and are neither intended to suggest fitness for human consumption nor to represent bacterial levels at all points in the Districts 300-mile piped system. Customers that need to know bacteria levels in their process water, wash water, or irrigation water for compliance purposes should collect their own samples downstream from their meter.

Aqueduct Water Bacteriological Analysis, Samples taken at District Headquarters:

Bacteria Analysis