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 6, 2015
Chloride No MCL 100 mg/L + May 10, 2016
Chlorine Residual 4.0 mg/L + 2.9  mg/L + May 31,  2016
Mercury 0.002 mg/L + < 0.00020 mg/L + July 6, 2015
Radon*** 300 pci/L**** < 100 pci/L Jan. 2016
Total Coliforms > 5% positive 0.5 % positive May 2016
Hardness No MCL 122 mg/L + May 10, 2016
Hardness No MCL 7.1 grains/gallon May 10, 2016
* 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