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.
LabPhoto
Substance Maximum Contaminant Level* Most Recent Result Date
Arsenic 0.01 mg/L < 0.001 mg/L + July 10, 2017
Chloride No MCL 50 mg/L + August 15, 2017
Chlorine Residual 4.0 mg/L + 3.8  mg/L + August 29, 2017
Mercury 0.002 mg/L + < 0.00020 mg/L + July 10, 2017
Radon*** 300 pci/L**** < 100 pci/L Jan. 2016
Total Coliforms > 5% positive 0% positive August 2017
Hardness No MCL 64 mg/L + August 15, 2017
Hardness No MCL 3.7 grains/gallon August
15, 2017
* 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.
** ug/L = micrograms per liter = parts per billion
*** Raw water sample
**** pci/L = picoCuries per liter
+ mg/L = milligrams per liter or parts per million