The Power of Information

National Drinking Water Database

Randall-Bold Water Treatment Plant Utilities - Concord, CA

Serves 30,000 people


Chlorate is a disinfection byproduct (unregulated chlorine dioxide byproduct), an herbicide and a pollutant from explosives.
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
0 days
Test Days Exceeding Legal LimitsNumber of days in which the samples taken in that day exceed the Maximum Contaminant Level (Depending on the contaminant and its MCL, that may or may not trigger an MCL violation. Some MCLs are based on averages spanning several months to a year)
0 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
9 days
Tests ConductedNumber of individual tests done for this contaminant
9 tests

Testing Summary

Health Limit
Legal Limit

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
ChlorateChlorate is a disinfection byproduct (unregulated chlorine dioxide byproduct), an herbicide and a pollutant from explosives.380.11 ppb
690 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
NOTE: Each dot in the above graph represents one month.
* Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.

Health Based and Legal Limits for Chlorate

Health Based Limits for Chlorate

There are no health based standards that EWG is using for this chemical

Testing Results

Testing DateAverage
Samples taken that dayNumber of Non-DetectsRange of Results
2004-09-07290 ppb10290 ppb
2004-08-10250 ppb10250 ppb
2004-07-06260 ppb10260 ppb
2004-06-22300 ppb10300 ppb
2004-05-1855 ppb1055 ppb
2004-04-20456 ppb10456 ppb
2004-03-16590 ppb10590 ppb
2004-02-24690 ppb10690 ppb
2004-01-20530 ppb10530 ppb