Recent Water Quality Results

Water quality reports are found in the table below. The substances shown are ones that CCWD customers have the most questions about.

You can also view the CCWD Annual Water Quality Report, which lists the annual results for these substances as well as many others.

Have questions? Call the CCWD Water Quality Hotline at 925-688-8156 or email us.

Water Quality Results

Substance Maximum Contaminant Level* Most Recent Result Date Source
Arsenic 0.01 mg/L < 0.001 mg/L 7/11/2017 R/BCWO annual
Chloride No MCL
(65 mg/L CCWD Internal Action Level)
51 mg/L 2/13/2018 R/BCWO
Chlorine Residual 4.0 mg/L 3.0 mg/L 2/27/2018 R/BCWO
Mercury 0.002 mg/L <0.00020 mg/L 7/11/2017 R/BCWO annual
Radon ** 300 pci/L <100pci/L 1/2016 Mallard Res; triennial
Total Coliforms >5% positive 0% positive 2/2018 Last DDW report
Hardness No MCL 94 mg/L 2/13/2018  R/BCWO
Hardness No MCL 5.5 grains/gallon 2/13/2018  R/BCWO

*Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water based on health risk coupled with economic and technical feasibility for control/treatment.                

**untreated (raw) water sample

pci/L = picocuries per liter

mg/L = milligrams per liter = parts per million

ug/L = micrograms per liter = parts per billion