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EWG's Tap Water Database — 2019 UPDATE

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Total trihalomethanes (TTHMs)

City of Aiken

Trihalomethanes are cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform. Read More.

Studies conducted in the U.S. and Europe have found that drinking tap water that carries disinfection byproducts increases the risk of developing bladder cancer. In animal studies, all trihalomethanes cause liver, kidney and intestinal tumors. Some human epidemiological studies also reported an association between disinfection byproducts and an increased risk of problems during pregnancy, including spontaneous miscarriage, cardiovascular defects, neural tube defects and low birth weight.

The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.

Click here to read more about disinfection byproducts.

 

180

Samples

12

Samples exceeding legal limit (MCL)

130

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201223.0 ppb6433ND - 128.0 ppb
201335.8 ppb5237ND - 149.8 ppb
201428.5 ppb1615ND - 75.4 ppb
201527.5 ppb16163.30 ppb - 68.4 ppb
201623.1 ppb1615ND - 64.7 ppb
201730.1 ppb1614ND - 70.1 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.15 ppb

The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.

EPA Maximum Contaminant
Level (MCL) 80 ppb

The legal limit for the group of four trihalomethanes, established in 1998, was based on the need for residual disinfectant levels in water served to customers and the cost of treatment. This limit does not fully protect against the risk of cancer due to exposure to trihalomethanes.

ppb = parts per billion

All test results

Date Lab ID Result
2012-02-292120301-1972.3 ppb
2012-02-292120301-2065.6 ppb
2012-02-292120301-21ND
2012-02-292120301-22ND
2012-02-292120301-2313.6 ppb
2012-02-292120301-2435.4 ppb
2012-02-292120301-25ND
2012-02-292120301-2618.4 ppb
2012-02-292120301-2726.5 ppb
2012-02-292120301-28ND
2012-02-292120301-2930.6 ppb
2012-02-292120301-305.32 ppb
2012-02-292120301-31ND
2012-02-292120301-32ND
2012-02-292120301-33ND
2012-02-292120301-34ND
2012-06-132120614-4155.1 ppb
2012-06-132120614-4267.1 ppb
2012-06-132120614-4315.4 ppb
2012-06-132120614-44ND
2012-06-132120614-457.67 ppb
2012-06-132120614-466.71 ppb
2012-06-132120614-47ND
2012-06-132120614-4826.7 ppb
2012-06-132120614-4958.9 ppb
2012-06-132120614-50ND
2012-06-132120614-5142.5 ppb
2012-06-132120614-52ND
2012-06-132120614-53ND
2012-06-132120614-54ND
2012-06-132120614-55ND
2012-06-132120614-56ND
2012-09-122120913-19109.0 ppb
2012-09-122120913-20128.0 ppb
2012-09-122120913-2116.4 ppb
2012-09-122120913-228.00 ppb
2012-09-122120913-2366.6 ppb
2012-09-122120913-24105.0 ppb
2012-09-122120913-25ND
2012-09-122120913-2658.7 ppb
2012-09-122120913-28ND
2012-09-122120913-29114.3 ppb
2012-09-122120913-30ND
2012-09-122120913-3129.8 ppb
2012-09-122120913-3240.2 ppb
2012-09-122120913-33ND
2012-09-122120913-34ND
2012-09-132120913-27ND
2012-12-122121213-1958.7 ppb
2012-12-122121213-2049.4 ppb
2012-12-122121213-21ND
2012-12-122121213-225.45 ppb
2012-12-122121213-2336.0 ppb
2012-12-122121213-2423.6 ppb
2012-12-122121213-25ND
2012-12-122121213-2623.6 ppb
2012-12-122121213-27ND
2012-12-122121213-28ND
2012-12-122121213-2949.4 ppb
2012-12-122121213-30ND
2012-12-122121213-31ND
2012-12-122121213-32ND
2012-12-122121213-33ND
2012-12-122121213-34ND
2013-03-273030015-01RE1103.8 ppb
2013-03-273030015-02RE1107.2 ppb
2013-03-273030015-034.20 ppb
2013-03-273030015-042.50 ppb
2013-03-273030015-0534.4 ppb
2013-03-273030015-0637.6 ppb
2013-03-273030015-07ND
2013-03-273030015-0819.3 ppb
2013-03-273030015-0951.5 ppb
2013-03-273030015-10ND
2013-03-273030015-1153.6 ppb
2013-03-273030015-12ND
2013-03-273030015-13ND
2013-03-273030015-141.60 ppb
2013-03-273030015-15ND
2013-03-273030015-16ND
2013-06-193060023-01RE1106.3 ppb
2013-06-193060023-02RE1142.7 ppb
2013-06-193060023-035.20 ppb
2013-06-193060023-042.70 ppb
2013-06-193060023-05RE167.2 ppb
2013-06-193060023-06RE194.7 ppb
2013-06-193060023-07ND
2013-06-193060023-08RE1115.9 ppb
2013-06-193060023-09RE1117.7 ppb
2013-06-193060023-10ND
2013-06-193060023-11RE1149.8 ppb
2013-06-193060023-12ND
2013-06-193060023-13ND
2013-06-193060023-14RE177.9 ppb
2013-06-193060023-152.20 ppb
2013-06-193060023-16ND
2013-09-183090015-0159.5 ppb
2013-09-183090015-0250.9 ppb
2013-09-183090015-0310.7 ppb
2013-09-183090015-042.30 ppb
2013-09-183090015-0559.6 ppb
2013-09-183090015-0656.8 ppb
2013-09-183090015-07ND
2013-09-183090015-0865.4 ppb
2013-09-183090015-0952.1 ppb
2013-09-183090015-10ND
2013-09-183090015-1148.7 ppb
2013-09-183090015-12ND
2013-09-183090015-13ND
2013-09-183090015-1442.1 ppb
2013-09-183090015-152.50 ppb
2013-09-183090015-161.000 ppb
2013-11-203110004-0158.2 ppb
2013-11-203110004-024.40 ppb
2013-11-203110004-037.70 ppb
2013-11-203110004-0441.4 ppb
2014-02-264020324-0133.0 ppb
2014-02-264020324-02ND
2014-02-264020324-036.90 ppb
2014-02-264020324-0419.3 ppb
2014-05-214050227-0167.8 ppb
2014-05-214050227-024.40 ppb
2014-05-214050227-0358.0 ppb
2014-05-214050227-0428.9 ppb
2014-08-204080430-0158.4 ppb
2014-08-204080430-025.10 ppb
2014-08-204080430-0360.8 ppb
2014-08-204080430-0475.4 ppb
2014-11-244110019-0122.9 ppb
2014-11-244110019-024.70 ppb
2014-11-244110019-032.40 ppb
2014-11-244110019-047.20 ppb
2015-02-255020019-0126.3 ppb
2015-02-255020019-028.50 ppb
2015-02-255020019-038.90 ppb
2015-02-255020019-0420.1 ppb
2015-05-205050006-0150.8 ppb
2015-05-205050006-026.90 ppb
2015-05-205050006-0347.8 ppb
2015-05-205050006-0439.1 ppb
2015-08-265080042-0168.4 ppb
2015-08-265080042-026.10 ppb
2015-08-265080042-0364.1 ppb
2015-08-265080042-0418.8 ppb
2015-11-245110026-0150.6 ppb
2015-11-245110026-025.30 ppb
2015-11-245110026-033.30 ppb
2015-11-245110026-0415.6 ppb
2016-02-246020026-0411.1 ppb
2016-02-246020026-0126.4 ppb
2016-02-246020026-022.40 ppb
2016-02-246020026-031.000 ppb
2016-05-256050026-0423.8 ppb
2016-05-256050026-0126.5 ppb
2016-05-256050026-024.20 ppb
2016-05-256050026-0333.3 ppb
2016-08-246080042-0442.5 ppb
2016-08-246080042-0164.7 ppb
2016-08-246080042-025.30 ppb
2016-08-246080042-0362.9 ppb
2016-11-226110006-0425.6 ppb
2016-11-226110006-0131.8 ppb
2016-11-226110006-02ND
2016-11-226110006-038.40 ppb
2017-02-227020006-0416.3 ppb
2017-02-227020006-0152.0 ppb
2017-02-227020006-02ND
2017-02-227020006-0339.9 ppb
2017-05-237050026-049.80 ppb
2017-05-237050026-0150.9 ppb
2017-05-237050026-024.00 ppb
2017-05-237050026-0351.3 ppb
2017-08-227080025-0452.1 ppb
2017-08-227080025-0162.8 ppb
2017-08-227080025-02ND
2017-08-227080025-0370.1 ppb
2017-11-207110006-0421.9 ppb
2017-11-207110006-0124.9 ppb
2017-11-207110006-021.000 ppb
2017-11-207110006-0324.0 ppb