Chlorate
Northampton Bucks County Municipal Authority
Chlorate forms in drinking water as a byproduct of disinfection. Chlorate impairs thyroid function, making chlorate exposure most harmful during pregnancy and childhood. Read More.
In 2002, California scientists proposed an advisory value, called an action level, for chlorate at 200 parts per billion. Between 2013 and 2015, the EPA collected data through the Unregulated Contaminant Monitoring Rule program and found that over 15 percent of water tests from 38 percent of utilities had chlorate levels above a health-protective concentration, which federal scientists defined as 210 parts per billion, nearly equivalent to the California advisory value.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | N/A | 0 | 0 | N/A |
2015 | 78.1 ppb | 46 | 34 | ND - 200.0 ppb |
2016 | N/A | 0 | 0 | N/A |
2017 | N/A | 0 | 0 | N/A |
2018 | N/A | 0 | 0 | N/A |
2019 | N/A | 0 | 0 | N/A |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 210 ppb
The EWG Health Guideline of 210 ppb for chlorate was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against hormone disruption.
ppb = parts per billion
All test results
Date | Lab ID | Result |
---|---|---|
2015-02-12 | 00111 022015 | 38.0 ppb |
2015-02-12 | 00109 022015 | 150.0 ppb |
2015-02-12 | 00112 022015 | ND |
2015-02-12 | 00110 022015 | ND |
2015-02-12 | 00114 022015 | 110.0 ppb |
2015-02-12 | 00001 022015 | 130.0 ppb |
2015-02-12 | 00115 022015 | ND |
2015-02-12 | 00113 022015 | 29.0 ppb |
2015-02-12 | 00107 022015 | 40.0 ppb |
2015-02-12 | 99001 022015 | 130.0 ppb |
2015-02-12 | 00108 022015 | ND |
2015-02-12 | 00106 022015 | 99.0 ppb |
2015-02-18 | 00104 022015 | 110.0 ppb |
2015-02-18 | 00105 022015 | ND |
2015-02-18 | 00102 022015 | ND |
2015-02-18 | 00103 022015 | 72.0 ppb |
2015-02-18 | 99001 022015 UCM | 200.0 ppb |
2015-02-18 | 99001 022015 UCM | 150.0 ppb |
2015-02-18 | 99001 022015 UCM | 150.0 ppb |
2015-02-18 | 00101 022015 | 95.0 ppb |
2015-02-18 | 00010 022015 | 110.0 ppb |
2015-05-12 | 00001 072015 | 140.0 ppb |
2015-05-12 | 00010 072015 | 150.0 ppb |
2015-08-18 | 00113 0815 | ND |
2015-08-18 | 00112 0815 | ND |
2015-08-18 | 00010 0815 | 150.0 ppb |
2015-08-18 | 00001 0815 | 150.0 ppb |
2015-08-18 | 00115 0815 | ND |
2015-08-18 | 0010 0815 | 56.0 ppb |
2015-08-18 | 99001 0815 | 120.0 ppb |
2015-08-18 | 00104 0815 | 78.0 ppb |
2015-08-18 | 00114 0815 | 57.0 ppb |
2015-08-18 | 00102 0815 | ND |
2015-08-18 | 00103 0815 | 72.0 ppb |
2015-08-25 | 99001.0815 | 180.0 ppb |
2015-08-25 | 99001 0815 | 170.0 ppb |
2015-08-25 | 00106 0815 | 72.0 ppb |
2015-08-25 | 99001_0815 | 72.0 ppb |
2015-08-25 | 00111 0815 | 34.0 ppb |
2015-08-25 | 00109 0815 | 140.0 ppb |
2015-08-25 | 00108 0815 | ND |
2015-08-25 | 00110 0815 | ND |
2015-08-25 | 00105 0815 | 23.0 ppb |
2015-08-25 | 00107 0815 | 56.0 ppb |
2015-11-17 | 00010 1115 | 120.0 ppb |
2015-11-17 | 00001 1115 | 140.0 ppb |