Chloroform
Watertown City
Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Read More.
In addition to tap water disinfection, chloroform pollution in the environment also comes from industrial discharges from pulp and paper mills, and from urban wastewater effluent. Human studies show that chloroform damages the kidneys, liver and central nervous system. In animals, chloroform causes infertility, birth defects and cancer.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | 55.2 ppb | 34 | 34 | 2.80 ppb - 129.0 ppb |
2015 | 45.0 ppb | 48 | 48 | 13.0 ppb - 97.0 ppb |
2016 | 54.5 ppb | 49 | 49 | 15.0 ppb - 117.0 ppb |
2017 | 56.9 ppb | 50 | 48 | ND - 120.0 ppb |
2018 | 53.6 ppb | 48 | 48 | 17.0 ppb - 120.0 ppb |
2019 | 58.3 ppb | 48 | 48 | 17.0 ppb - 120.0 ppb |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.4 ppb
The EWG Health Guideline of 0.4 ppb for chloroform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
ppb = parts per billion
All test results
Date | Lab ID | Result |
---|---|---|
2014-02-05 | 1401657-012 | 14.0 ppb |
2014-02-05 | 1401657-011 | 14.0 ppb |
2014-02-05 | 1401657-010 | 15.0 ppb |
2014-02-05 | 1401657-007 | 22.0 ppb |
2014-02-05 | 1401657-013 | 2.80 ppb |
2014-04-02 | 1404398-009 | 22.0 ppb |
2014-05-07 | 1406257-011 | 35.0 ppb |
2014-05-07 | 1406257-012 | 37.0 ppb |
2014-05-07 | 1406257-001 | 43.0 ppb |
2014-05-07 | 1406257-004 | 37.0 ppb |
2014-07-16 | 1410755-011 | 81.0 ppb |
2014-07-16 | 1410755-012 | 71.0 ppb |
2014-07-16 | 1410755-010 | 93.0 ppb |
2014-07-16 | 1410755-007 | 129.0 ppb |
2014-08-06 | 1412351-007 | 105.0 ppb |
2014-08-06 | 1412351-012 | 74.0 ppb |
2014-08-06 | 1412351-011 | 77.0 ppb |
2014-08-06 | 1412351-010 | 89.0 ppb |
2014-09-10 | 1414832-009 | 97.0 ppb |
2014-09-10 | 1414832-011 | 65.0 ppb |
2014-09-10 | 1414832-008 | 78.0 ppb |
2014-09-10 | 1414832-012 | 67.0 ppb |
2014-10-08 | 1416618-012 | 47.0 ppb |
2014-10-08 | 1416618-010 | 44.0 ppb |
2014-10-08 | 1416618-011 | 45.0 ppb |
2014-10-08 | 1416618-007 | 66.0 ppb |
2014-11-05 | 1418303-010 | 68.0 ppb |
2014-11-05 | 1418303-007 | 85.0 ppb |
2014-11-05 | 1418303-011 | 49.0 ppb |
2014-11-05 | 1418303-012 | 57.0 ppb |
2014-12-03 | 1419724-012 | 35.0 ppb |
2014-12-03 | 1419724-011 | 33.0 ppb |
2014-12-03 | 1419724-008 | 26.0 ppb |
2014-12-03 | 1419724-009 | 53.0 ppb |
2015-01-14 | 1500772-010 | 18.0 ppb |
2015-01-14 | 1500772-012 | 14.0 ppb |
2015-01-15 | 1500772-011 | 13.0 ppb |
2015-01-15 | 1500772-007 | 25.0 ppb |
2015-02-04 | 1501522-011 | 14.0 ppb |
2015-02-04 | 1501522-008 | 22.0 ppb |
2015-02-04 | 1501522-012 | 16.0 ppb |
2015-02-04 | 1501522-009 | 23.0 ppb |
2015-03-04 | 1502825-010 | 19.0 ppb |
2015-03-04 | 1502825-011 | 16.0 ppb |
2015-03-04 | 1502825-012 | 14.0 ppb |
2015-03-04 | 1502825-007 | 25.0 ppb |
2015-04-08 | 1504564-012 | 20.0 ppb |
2015-04-08 | 1504564-010 | 22.0 ppb |
2015-04-08 | 1504564-011 | 19.0 ppb |
2015-04-08 | 1504564-007 | 23.0 ppb |
2015-05-06 | 1506084-012 | 51.0 ppb |
2015-05-06 | 1506084-010 | 51.0 ppb |
2015-05-06 | 1506084-007 | 50.0 ppb |
2015-05-06 | 1506084-011 | 51.0 ppb |
2015-06-03 | 1507791-012 | 34.0 ppb |
2015-06-03 | 1507791-010 | 33.0 ppb |
2015-06-03 | 1507791-011 | 45.0 ppb |
2015-06-03 | 1507791-007 | 49.0 ppb |
2015-07-08 | 1510103-011 | 64.0 ppb |
2015-07-08 | 1510103-012 | 61.0 ppb |
2015-07-08 | 1510103-010 | 66.0 ppb |
2015-07-08 | 1510103-007 | 97.0 ppb |
2015-08-05 | 1511980-012 | 62.0 ppb |
2015-08-05 | 1511980-011 | 59.0 ppb |
2015-08-05 | 1511980-007 | 85.0 ppb |
2015-08-05 | 1511980-010 | 68.0 ppb |
2015-09-09 | 1514301-010 | 97.0 ppb |
2015-09-09 | 1514301-012 | 75.0 ppb |
2015-09-09 | 1514301-011 | 73.0 ppb |
2015-09-09 | 1514301-007 | 88.0 ppb |
2015-10-07 | 1516030-012 | 43.0 ppb |
2015-10-07 | 1516030-011 | 39.0 ppb |
2015-10-07 | 1516030-006 | 44.0 ppb |
2015-10-07 | 1516030-009 | 56.0 ppb |
2015-11-04 | 1517576-010 | 67.0 ppb |
2015-11-04 | 1517576-011 | 46.0 ppb |
2015-11-04 | 1517576-007 | 63.0 ppb |
2015-11-04 | 1517576-012 | 47.0 ppb |
2015-12-02 | 1519086-011 | 35.0 ppb |
2015-12-02 | 1519086-012 | 40.0 ppb |
2015-12-02 | 1519086-007 | 57.0 ppb |
2015-12-02 | 1519086-010 | 62.0 ppb |
2016-01-06 | 1600312-010 | 32.0 ppb |
2016-01-06 | 1600312-011 | 19.0 ppb |
2016-01-06 | 1600312-007 | 29.0 ppb |
2016-01-06 | 1600312-012 | 22.0 ppb |
2016-02-03 | 1601638-012 | 22.0 ppb |
2016-02-03 | 1601638-007 | 30.0 ppb |
2016-02-03 | 1601638-011 | 21.0 ppb |
2016-02-03 | 1601638-010 | 21.0 ppb |
2016-03-02 | 1602966-007 | 23.0 ppb |
2016-03-02 | 1602966-010 | 15.0 ppb |
2016-03-02 | 1602966-011 | 16.0 ppb |
2016-03-02 | 1602966-012 | 17.0 ppb |
2016-04-06 | 1604789-007 | 39.0 ppb |
2016-04-06 | 1604789-012 | 34.0 ppb |
2016-04-06 | 1604789-010 | 44.0 ppb |
2016-04-06 | 1604789-011 | 36.0 ppb |
2016-05-04 | 1606613-010 | 69.0 ppb |
2016-05-04 | 1606613-012 | 43.0 ppb |
2016-05-04 | 1606613-007 | 78.0 ppb |
2016-05-04 | 1606613-011 | 49.0 ppb |
2016-06-08 | 1608681-014 | 49.0 ppb |
2016-06-08 | 1608681-009 | 74.0 ppb |
2016-06-08 | 1608681-013 | 55.0 ppb |
2016-06-08 | 1608681-006 | 75.0 ppb |
2016-06-08 | 1608681-012 | 70.0 ppb |
2016-07-06 | 1610588-011 | 77.0 ppb |
2016-07-06 | 1610588-010 | 102.0 ppb |
2016-07-06 | 1610588-012 | 73.0 ppb |
2016-07-06 | 1610588-007 | 96.0 ppb |
2016-08-03 | 1612539-009 | 56.0 ppb |
2016-08-03 | 1612539-012 | 94.0 ppb |
2016-08-03 | 1612539-010 | 57.0 ppb |
2016-08-03 | 1612539-007 | 104.0 ppb |
2016-09-07 | 1614875-012 | 72.0 ppb |
2016-09-07 | 1614875-007 | 117.0 ppb |
2016-09-07 | 1614875-010 | 112.0 ppb |
2016-09-07 | 1614875-011 | 72.0 ppb |
2016-10-05 | 1616823-002 | 63.0 ppb |
2016-10-05 | 1616823-011 | 46.0 ppb |
2016-10-05 | 1616823-009 | 112.0 ppb |
2016-10-05 | 1616823-012 | 45.0 ppb |
2016-11-02 | 1618348-010 | 48.0 ppb |
2016-11-02 | 1618348-012 | 45.0 ppb |
2016-11-02 | 1618348-007 | 78.0 ppb |
2016-11-02 | 1618348-011 | 40.0 ppb |
2016-12-07 | 1620270-012 | 31.0 ppb |
2016-12-07 | 1620270-009 | 79.0 ppb |
2016-12-07 | 1620270-002 | 40.0 ppb |
2016-12-07 | 1620270-011 | 30.0 ppb |
2017-01-04 | 1700403-004 | 17.0 ppb |
2017-01-04 | 1700403-011 | 41.0 ppb |
2017-01-04 | 1700403-002 | 23.0 ppb |
2017-01-04 | 1700403-003 | 17.0 ppb |
2017-02-01 | 1701549-003 | 36.0 ppb |
2017-02-01 | 1701549-004 | 24.0 ppb |
2017-02-01 | 1701549-002 | 17.0 ppb |
2017-02-01 | 1701549-001 | 15.0 ppb |
2017-03-01 | 1702919-002 | 20.0 ppb |
2017-03-01 | 1702919-001 | 19.0 ppb |
2017-03-01 | 1702919-004 | 20.0 ppb |
2017-03-01 | 1702919-003 | 38.0 ppb |
2017-04-05 | 1704744-004 | 24.0 ppb |
2017-04-05 | 1704744-003 | 24.0 ppb |
2017-04-05 | 1704744-001 | 32.0 ppb |
2017-04-05 | 1704744-002 | 40.0 ppb |
2017-05-03 | 1706368-001 | 75.0 ppb |
2017-05-03 | 1706368-004 | 65.0 ppb |
2017-05-03 | 1706368-002 | 52.0 ppb |
2017-05-03 | 1706368-003 | 54.0 ppb |
2017-05-31 | 1801970-005 | ND |
2017-05-31 | 1800236-005 | ND |
2017-06-07 | 1708525-003 | 64.0 ppb |
2017-06-07 | 1708525-001 | 92.0 ppb |
2017-06-07 | 1708525-004 | 63.0 ppb |
2017-06-07 | 1708525-002 | 95.0 ppb |
2017-07-05 | 1710148-001 | 103.0 ppb |
2017-07-05 | 1710148-004 | 86.0 ppb |
2017-07-05 | 1710148-003 | 115.0 ppb |
2017-07-05 | 1710148-002 | 87.0 ppb |
2017-08-02 | 1712271-003 | 120.0 ppb |
2017-08-02 | 1712271-004 | 100.0 ppb |
2017-08-02 | 1712271-002 | 100.0 ppb |
2017-08-02 | 1712271-001 | 120.0 ppb |
2017-09-06 | 1714647-001 | 109.0 ppb |
2017-09-06 | 1714647-002 | 85.0 ppb |
2017-09-06 | 1717647-004 | 87.0 ppb |
2017-09-06 | 1714647-003 | 110.0 ppb |
2017-10-04 | 1716498-002 | 57.0 ppb |
2017-10-04 | 1716498-004 | 50.0 ppb |
2017-10-04 | 1716498-003 | 77.0 ppb |
2017-10-04 | 1716498-001 | 80.0 ppb |
2017-11-01 | 1718017-003 | 55.0 ppb |
2017-11-01 | 1718017-0025 | 77.0 ppb |
2017-11-01 | 1718017-004 | 58.0 ppb |
2017-11-01 | 1718017-001 | 80.0 ppb |
2017-12-06 | 1719921-003 | 44.0 ppb |
2017-12-06 | 1719921-002 | 28.0 ppb |
2017-12-06 | 1719921-004 | 28.0 ppb |
2017-12-06 | 1719921-001 | 24.0 ppb |
2018-01-03 | 1800236-001 | 28.0 ppb |
2018-01-03 | 1800236-003 | 22.0 ppb |
2018-01-03 | 1800236-004 | 21.0 ppb |
2018-01-03 | 1800236-002 | 18.0 ppb |
2018-02-07 | 1801970-004 | 19.0 ppb |
2018-02-07 | 1801970-003 | 17.0 ppb |
2018-02-07 | 1801970-001 | 31.0 ppb |
2018-02-07 | 1801970-002 | 20.0 ppb |
2018-03-07 | 1803438-004 | 20.0 ppb |
2018-03-07 | 1803438-001 | 26.0 ppb |
2018-03-07 | 1803438-002 | 19.0 ppb |
2018-03-07 | 1803438-003 | 17.0 ppb |
2018-04-04 | 1804899-004 | 21.0 ppb |
2018-04-04 | 1804899-001 | 28.0 ppb |
2018-04-04 | 1804899-002 | 20.0 ppb |
2018-04-04 | 1804899-003 | 19.0 ppb |
2018-05-02 | 1806564-002 | 33.0 ppb |
2018-05-02 | 1806564-001 | 50.0 ppb |
2018-05-02 | 1806564-004 | 35.0 ppb |
2018-05-02 | 1806564-003 | 30.0 ppb |
2018-06-06 | 1808768-002 | 75.0 ppb |
2018-06-06 | 1808768-001 | 115.0 ppb |
2018-06-06 | 1808768-004 | 80.0 ppb |
2018-06-06 | 1808768-003 | 80.0 ppb |
2018-07-11 | 1811277-001 | 120.0 ppb |
2018-07-11 | 1811277-004 | 87.0 ppb |
2018-07-11 | 1811277-002 | 86.0 ppb |
2018-07-11 | 1811277-003 | 89.0 ppb |
2018-08-01 | 1812785-004 | 85.0 ppb |
2018-08-01 | 1812785-002 | 81.0 ppb |
2018-08-01 | 1812785-001 | 105.0 ppb |
2018-08-01 | 1812785-003 | 79.0 ppb |
2018-09-05 | 1815311-001 | 115.0 ppb |
2018-09-05 | 1815311-004 | 84.0 ppb |
2018-09-05 | 1815311-003 | 74.0 ppb |
2018-09-05 | 1815311-002 | 79.0 ppb |
2018-10-03 | 1817320-004 | 75.0 ppb |
2018-10-03 | 1817320-002 | 74.0 ppb |
2018-10-03 | 1817320-003 | 69.0 ppb |
2018-10-03 | 1817320-001 | 120.0 ppb |
2018-11-07 | 1819262-001 | 61.0 ppb |
2018-11-07 | 1819262-004 | 45.0 ppb |
2018-11-07 | 1819262-002 | 41.0 ppb |
2018-11-07 | 1819262-003 | 40.0 ppb |
2018-12-05 | 1820706-001 | 43.0 ppb |
2018-12-05 | 1820706-004 | 28.0 ppb |
2018-12-05 | 1820706-003 | 25.0 ppb |
2018-12-05 | 1820706-002 | 26.0 ppb |
2019-01-09 | 1900591-002 | 20.0 ppb |
2019-01-09 | 1900591-001 | 43.0 ppb |
2019-01-09 | 1900591-003 | 18.0 ppb |
2019-01-09 | 1900591-004 | 23.0 ppb |
2019-02-06 | 1901746-002 | 18.0 ppb |
2019-02-06 | 1901746-001 | 28.0 ppb |
2019-02-06 | 1901746-003 | 17.0 ppb |
2019-02-06 | 1901746-004 | 21.0 ppb |
2019-03-06 | 1903127-003 | 19.0 ppb |
2019-03-06 | 1903127-001 | 36.0 ppb |
2019-03-06 | 1903127-004 | 22.0 ppb |
2019-03-06 | 1903127-002 | 20.0 ppb |
2019-04-03 | 1904663-002 | 31.0 ppb |
2019-04-03 | 1904663-001 | 37.0 ppb |
2019-04-03 | 1904663-004 | 32.0 ppb |
2019-04-03 | 1904663-003 | 28.0 ppb |
2019-05-01 | 1906163-001 | 40.0 ppb |
2019-05-01 | 1906163-003 | 54.0 ppb |
2019-05-01 | 1906163-002 | 45.0 ppb |
2019-05-01 | 1906163-004 | 43.0 ppb |
2019-06-05 | 1908563-004 | 54.0 ppb |
2019-06-05 | 1908563-002 | 51.0 ppb |
2019-06-05 | 1908563-001 | 66.0 ppb |
2019-06-05 | 1908563-003 | 48.0 ppb |
2019-07-10 | 1911002-003 | 93.0 ppb |
2019-07-10 | 1911002-004 | 91.0 ppb |
2019-07-10 | 1911002-002 | 91.0 ppb |
2019-07-10 | 1911002-001 | 120.0 ppb |
2019-08-07 | 1912989-004 | 86.0 ppb |
2019-08-07 | 1912989-002 | 91.0 ppb |
2019-08-07 | 1912989-003 | 110.0 ppb |
2019-08-07 | 1912989-001 | 91.0 ppb |
2019-09-04 | 1914985-004 | 95.0 ppb |
2019-09-04 | 1914985-003 | 91.0 ppb |
2019-09-04 | 1914985-002 | 86.0 ppb |
2019-09-04 | 1914985-001 | 120.0 ppb |
2019-10-02 | 1916930-002 | 71.0 ppb |
2019-10-02 | 1916930-004 | 69.0 ppb |
2019-10-02 | 1916930-003 | 98.0 ppb |
2019-10-02 | 1916930-001 | 84.0 ppb |
2019-11-06 | 1918840-003 | 120.0 ppb |
2019-11-06 | 1918840-001 | 80.0 ppb |
2019-11-06 | 1918840-004 | 74.0 ppb |
2019-11-06 | 1918840-002 | 83.0 ppb |
2019-12-04 | 1920288-002 | 33.0 ppb |
2019-12-04 | 1920288-003 | 54.0 ppb |
2019-12-04 | 1920288-001 | 26.0 ppb |
2019-12-04 | 1920288-004 | 29.0 ppb |