Total trihalomethanes (TTHMs)
Erie County Water Authority (ECWA)
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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | 39.3 ppb | 48 | 48 | 8.70 ppb - 75.0 ppb |
2015 | 36.1 ppb | 51 | 51 | 13.6 ppb - 66.0 ppb |
2016 | 42.4 ppb | 48 | 48 | 15.0 ppb - 79.4 ppb |
2017 | 37.1 ppb | 47 | 47 | 10.6 ppb - 64.9 ppb |
2018 | 43.3 ppb | 48 | 48 | 17.4 ppb - 85.1 ppb |
2019 | 42.8 ppb | 48 | 48 | 14.0 ppb - 78.3 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 |
---|---|---|
2014-02-16 | 20140216_523 | 52.2 ppb |
2014-02-16 | 20140216_491 | 21.5 ppb |
2014-02-16 | 20140216_340 | 18.2 ppb |
2014-02-16 | 20140216_530 | 37.8 ppb |
2014-02-16 | 20140216_484 | 37.6 ppb |
2014-02-16 | 20140216_433 | 35.3 ppb |
2014-02-18 | 20140218_1047 | 26.8 ppb |
2014-02-18 | 20140218_402 | 21.3 ppb |
2014-02-18 | 20140218_527 | 26.0 ppb |
2014-02-18 | 20140218_393 | 34.1 ppb |
2014-02-18 | 20140218_291 | 66.1 ppb |
2014-02-18 | 20140218_391 | 25.8 ppb |
2014-05-19 | 20140519 | 33.6 ppb |
2014-05-19 | 20140519_393 | 33.1 ppb |
2014-05-19 | 20140519_391 | 34.1 ppb |
2014-05-19 | 20140519_291 | 34.8 ppb |
2014-05-19 | 20140519_402 | 25.9 ppb |
2014-05-19 | 20140519_491 | 24.7 ppb |
2014-05-19 | 20140519_530 | 36.8 ppb |
2014-05-19 | 20140519_1047 | 28.4 ppb |
2014-05-19 | 20140519_527 | 25.9 ppb |
2014-05-19 | 20140519_340 | 24.1 ppb |
2014-05-19 | 20140519_523 | 51.9 ppb |
2014-05-19 | 20140519_484 | 47.7 ppb |
2014-08-18 | 1408F19-005 | 62.0 ppb |
2014-08-18 | 1408F19-013 | 56.0 ppb |
2014-08-18 | 1408F19-001 | 69.0 ppb |
2014-08-18 | 1408F19-004 | 16.0 ppb |
2014-08-18 | 1408F19-022 | 68.0 ppb |
2014-08-18 | 1408F19-017 | 46.0 ppb |
2014-08-18 | 1408F19-008 | 59.0 ppb |
2014-08-18 | 1408F19-011 | 48.0 ppb |
2014-08-18 | 1408F19-020 | 48.0 ppb |
2014-08-18 | 1408F19-016 | 66.0 ppb |
2014-08-18 | 1408F19-019 | 56.0 ppb |
2014-08-18 | 1408F19-007 | 75.0 ppb |
2014-11-17 | 1412027-019 | 30.0 ppb |
2014-11-17 | 1412027-014 | 36.0 ppb |
2014-11-17 | 1412027-012 | 50.0 ppb |
2014-11-17 | 1412027-009 | 8.70 ppb |
2014-11-17 | 1412027-013 | 49.0 ppb |
2014-11-17 | 1412027-002 | 31.0 ppb |
2014-11-17 | 1412027-010 | 41.0 ppb |
2014-11-17 | 1412027-001 | 56.0 ppb |
2014-11-17 | 1412027-005 | 20.0 ppb |
2014-11-17 | 1412027-007 | 30.0 ppb |
2014-11-17 | 1412027-017 | 25.0 ppb |
2014-11-17 | 1412027-004 | 39.0 ppb |
2015-02-17 | 523-20150217 | 56.9 ppb |
2015-02-17 | 340-20150217 | 19.3 ppb |
2015-02-17 | 391-20150217 | 26.4 ppb |
2015-02-17 | 433-20150217 | 27.7 ppb |
2015-02-17 | 1047-20150217 | 23.3 ppb |
2015-02-17 | 291-20150217 | 18.6 ppb |
2015-02-17 | 527-20150217 | 25.4 ppb |
2015-02-17 | 393-20150217 | 27.8 ppb |
2015-02-17 | 491-20150217 | 18.9 ppb |
2015-02-17 | 402-20150217 | 18.9 ppb |
2015-02-17 | 484-20150217 | 34.7 ppb |
2015-02-18 | 530-20150218 | 28.7 ppb |
2015-05-18 | 20150518-A | 30.6 ppb |
2015-05-18 | 340616W | 35.0 ppb |
2015-05-18 | 340616L | 31.0 ppb |
2015-05-18 | 340616A | 45.0 ppb |
2015-05-18 | 340616R | 36.0 ppb |
2015-05-18 | 340616B | 35.0 ppb |
2015-05-18 | 340616F | 42.0 ppb |
2015-05-18 | 34066BA | 29.0 ppb |
2015-05-18 | 340616 | 41.0 ppb |
2015-05-18 | 340616ED | 51.0 ppb |
2015-05-18 | 340616N | 38.0 ppb |
2015-05-18 | 20150518 | 29.4 ppb |
2015-05-18 | 340616TR | 17.0 ppb |
2015-05-18 | 20150518-B | 44.9 ppb |
2015-05-18 | 340616M | 31.0 ppb |
2015-08-20 | 347018-2 | 38.0 ppb |
2015-08-20 | 347018-1 | 64.0 ppb |
2015-08-21 | 347018-4 | 26.0 ppb |
2015-08-21 | 347018-6 | 24.0 ppb |
2015-08-21 | 347018-10 | 56.0 ppb |
2015-08-21 | 347018-7 | 52.0 ppb |
2015-08-21 | 347018-9 | 66.0 ppb |
2015-08-21 | 347018-3 | 55.0 ppb |
2015-08-21 | 347018-5 | 61.0 ppb |
2015-08-21 | 347018-12 | 42.0 ppb |
2015-08-21 | 347018-8 | 65.0 ppb |
2015-08-21 | 347018-11 | 40.0 ppb |
2015-11-16 | 11/16/2015-484 | 13.6 ppb |
2015-11-16 | 11/16/2015-523 | 15.0 ppb |
2015-11-16 | 11/16/2015-340 | 28.0 ppb |
2015-11-16 | 11/16/2015-530 | 31.0 ppb |
2015-11-16 | 11/16/2015-291 | 26.0 ppb |
2015-11-16 | 11/16/2015-433 | 48.0 ppb |
2015-11-16 | 11/16/2015-491 | 27.0 ppb |
2015-11-16 | 11/16/2015-393 | 41.0 ppb |
2015-11-16 | 11/16/2015-402 | 36.0 ppb |
2015-11-16 | 11/16/2015-1047 | 41.0 ppb |
2015-11-16 | 11/16/2015-391 | 51.0 ppb |
2015-11-16 | 11/16/2015-527 | 33.0 ppb |
2016-02-16 | 02/16/2016-527 | 20.1 ppb |
2016-02-16 | 02/16/2016-393 | 27.3 ppb |
2016-02-16 | 02/16/2016-402 | 18.4 ppb |
2016-02-16 | 02/16/2016-291 | 18.0 ppb |
2016-02-16 | 02/16/2016-1047 | 35.0 ppb |
2016-02-16 | 02/16/2016-391 | 33.0 ppb |
2016-02-16 | 02/16/2016-484 | 31.0 ppb |
2016-02-17 | 02/17/2016-530 | 20.0 ppb |
2016-02-17 | 02/17/2016-523 | 47.0 ppb |
2016-02-18 | 02/18/2016-433 | 26.0 ppb |
2016-02-18 | 02/18/2016-340 | 19.4 ppb |
2016-02-18 | 02/18/2016-491 | 20.0 ppb |
2016-05-16 | 05/16/2016-291 | 27.0 ppb |
2016-05-16 | 05/16/2016-523 | 27.0 ppb |
2016-05-16 | 05/16/2016-402 | 30.0 ppb |
2016-05-16 | 05/16/2016-527 | 31.0 ppb |
2016-05-16 | 05/16/2016-393 | 37.0 ppb |
2016-05-16 | 05/16/2016-484 | 41.0 ppb |
2016-05-16 | 05/16/2016-433 | 51.0 ppb |
2016-05-16 | 05/16/2016-391 | 42.0 ppb |
2016-05-16 | 05/16/2016-1047 | 28.0 ppb |
2016-05-16 | 05/16/2016-340 | 27.0 ppb |
2016-05-16 | 05/16/2016-491 | 27.0 ppb |
2016-05-16 | 05/16/2016-530 | 35.0 ppb |
2016-08-15 | 1608H81-013 | 26.8 ppb |
2016-08-15 | 1608H81-001 | 79.4 ppb |
2016-08-15 | 1608H81-007 | 58.2 ppb |
2016-08-15 | 1608H81-002 | 75.6 ppb |
2016-08-15 | 1608H81-008 | 67.5 ppb |
2016-08-15 | 1608H81-009 | 60.8 ppb |
2016-08-15 | 1608H81-010 | 77.1 ppb |
2016-08-15 | 1608H81-015 | 69.1 ppb |
2016-08-15 | 1608H81-003 | 68.0 ppb |
2016-08-15 | 1608H81-014 | 31.5 ppb |
2016-08-15 | 1608H81-005 | 60.3 ppb |
2016-08-15 | 1608H81-012 | 66.0 ppb |
2016-11-14 | 704956020 | 37.6 ppb |
2016-11-14 | 704956013 | 51.8 ppb |
2016-11-14 | 704956014 | 30.9 ppb |
2016-11-14 | 704956011 | 54.4 ppb |
2016-11-14 | 704956017 | 44.4 ppb |
2016-11-14 | 704956010 | 57.6 ppb |
2016-11-14 | 704956007 | 15.0 ppb |
2016-11-14 | 704956001 | 61.0 ppb |
2016-11-14 | 704656004 | 74.0 ppb |
2016-11-14 | 704956008 | 36.3 ppb |
2016-11-14 | 704956002 | 69.9 ppb |
2016-11-14 | 705335001 | 46.0 ppb |
2017-02-21 | 7011956014 | 42.9 ppb |
2017-02-21 | 7011956016 | 23.7 ppb |
2017-02-21 | 7011956012 | 26.4 ppb |
2017-02-21 | 7011956001 | 37.3 ppb |
2017-02-21 | 7011956002 | 24.3 ppb |
2017-02-21 | 7011956009 | 26.8 ppb |
2017-02-21 | 7011956021 | 25.0 ppb |
2017-02-21 | 7011956007 | 64.9 ppb |
2017-02-21 | 7011956004 | 49.4 ppb |
2017-02-21 | 7011956015 | 35.8 ppb |
2017-02-21 | 7011956019 | 25.5 ppb |
2017-05-15 | WOHLHUETER 5152 | 36.5 ppb |
2017-05-15 | AUTO INF 5152017 | 49.2 ppb |
2017-05-15 | FELLOW BAP 51520 | 55.2 ppb |
2017-05-15 | RICE HILL 515201 | 25.1 ppb |
2017-05-15 | TREVETT TANK 515 | 14.0 ppb |
2017-05-15 | TOPS MRKT 515201 | 23.3 ppb |
2017-05-15 | 3330 BAKER 51520 | 24.7 ppb |
2017-05-15 | NAPA AUTO 515201 | 35.1 ppb |
2017-05-15 | MARILLA STAT 515 | 27.0 ppb |
2017-05-16 | BENNING TANK 516 | 58.2 ppb |
2017-05-16 | LACK FIRE 2 5162 | 28.7 ppb |
2017-08-14 | 7027324003 | 56.6 ppb |
2017-08-14 | 7027324004 | 62.7 ppb |
2017-08-14 | 7027318002 | 46.0 ppb |
2017-08-14 | 7027324001 | 44.8 ppb |
2017-08-14 | 7027318001 | 23.2 ppb |
2017-08-14 | 7027319004 | 51.1 ppb |
2017-08-14 | 7027318007 | 53.9 ppb |
2017-08-14 | 7027319002 | 32.7 ppb |
2017-08-14 | 7027318004 | 47.3 ppb |
2017-08-14 | 7027324005 | 48.6 ppb |
2017-08-15 | 7027324009 | 37.3 ppb |
2017-08-15 | 7027324008 | 32.5 ppb |
2017-12-01 | 7037142003 | 48.9 ppb |
2017-12-01 | 7037142011 | 26.8 ppb |
2017-12-01 | 7037142013 | 24.5 ppb |
2017-12-01 | 7037142002 | 22.0 ppb |
2017-12-01 | 7037142004 | 45.8 ppb |
2017-12-01 | 7037142016 | 50.9 ppb |
2017-12-01 | 7037142017 | 48.5 ppb |
2017-12-01 | 7037142007 | 46.3 ppb |
2017-12-01 | 7037142009 | 28.1 ppb |
2017-12-01 | 7037142001 | 10.6 ppb |
2017-12-01 | 7037142018 | 39.6 ppb |
2017-12-01 | 7037142020 | 23.5 ppb |
2017-12-01 | 7037142014 | 32.9 ppb |
2018-02-12 | 7042886008 | 18.9 ppb |
2018-02-12 | 7042886001 | 32.2 ppb |
2018-02-12 | 7042886021 | 49.0 ppb |
2018-02-12 | 7042886010 | 20.9 ppb |
2018-02-12 | 7042886017 | 35.3 ppb |
2018-02-12 | 7042886004 | 34.8 ppb |
2018-02-12 | 7042886012 | 17.4 ppb |
2018-02-12 | 7042886003 | 34.3 ppb |
2018-02-12 | 7042886014 | 42.7 ppb |
2018-02-12 | 7042886019 | 21.3 ppb |
2018-02-12 | 7042886011 | 63.3 ppb |
2018-02-12 | 7042886005 | 32.8 ppb |
2018-05-14 | ECWA7 DBP 2ND Q | 34.6 ppb |
2018-05-14 | ECWA 3 DBP 2ND Q | 29.0 ppb |
2018-05-14 | ECWA 5 DBP 2ND Q | 32.3 ppb |
2018-05-14 | ECWA 2 DBP 2ND Q | 30.0 ppb |
2018-05-14 | ECWA 4 DBP 2ND Q | 42.8 ppb |
2018-05-14 | ECWA12 DBP 2ND Q | 30.7 ppb |
2018-05-14 | ECWA10 DBP 2ND Q | 33.0 ppb |
2018-05-14 | ECWA 1 DBP 2ND Q | 38.0 ppb |
2018-05-14 | ECWA9 DBP 2ND Q | 27.4 ppb |
2018-05-14 | ECWA 6 DBP 2ND Q | 38.0 ppb |
2018-05-15 | ECWA11 DBP 2ND Q | 29.2 ppb |
2018-05-16 | ECWA8 DBP 2ND Q | 37.3 ppb |
2018-08-13 | DBP2 ECWA 3RDQ 1 | 37.9 ppb |
2018-08-13 | DBP2 ECWA 3RDQ18 | 67.0 ppb |
2018-08-13 | DBP 2 ECWA 3RDQ | 63.2 ppb |
2018-08-13 | DBP2 ECWA 3RDQ 1 | 82.9 ppb |
2018-08-13 | DBP 2 ECWA 3RDQ | 82.0 ppb |
2018-08-13 | DBP2 ECWA 3RD Q1 | 30.0 ppb |
2018-08-13 | DBP2 ECWA 3RD Q | 76.8 ppb |
2018-08-13 | DBP2 ECWA 3RDQ 1 | 79.0 ppb |
2018-08-13 | DBP 2 ECWA 3RD Q | 52.3 ppb |
2018-08-13 | DBP 2 ECWA 3RDQ1 | 69.7 ppb |
2018-08-13 | DBP2 ECWA 3RD Q1 | 85.1 ppb |
2018-08-13 | DBP2 ECWA 3RDQ 1 | 57.2 ppb |
2018-12-04 | ECWA 4TH Q 18 12 | 51.5 ppb |
2018-12-04 | ECWA DBP2 4THQ 1 | 45.3 ppb |
2018-12-04 | ECWA DBP2 4THQ 1 | 51.5 ppb |
2018-12-04 | ECWA DBP 4THQ 18 | 40.0 ppb |
2018-12-04 | ECWA DBP 4TH Q 1 | 51.5 ppb |
2018-12-04 | ECWA DBP2 4THQ18 | 34.0 ppb |
2018-12-04 | ECWA DBP 4TH Q 1 | 33.0 ppb |
2018-12-04 | ECWA DBP 4THQ 18 | 20.9 ppb |
2018-12-04 | DBP2 ECWA 4THQ 1 | 33.3 ppb |
2018-12-04 | ECWA DBP 4THQ 18 | 48.0 ppb |
2018-12-04 | ECWA DBP 4THQ 18 | 39.0 ppb |
2018-12-04 | ECWA DBP 4THQ 18 | 42.0 ppb |
2019-02-19 | 484 DBP 1ST Q 19 | 41.0 ppb |
2019-02-19 | 527 DBP 1ST Q 19 | 24.0 ppb |
2019-02-19 | 433 DBP 1ST Q 19 | 43.0 ppb |
2019-02-19 | 491 DBP 1ST Q 19 | 29.0 ppb |
2019-02-19 | SITE 340 1ST Q 2 | 27.0 ppb |
2019-02-19 | SITE 391 DBP 1ST | 30.2 ppb |
2019-02-19 | SITE 393 DBP 1ST | 33.0 ppb |
2019-02-19 | 523 DBP 1ST Q 19 | 49.0 ppb |
2019-02-19 | SITE 402 DBP 1ST | 30.4 ppb |
2019-02-19 | 1047 DBP 1ST Q 1 | 30.9 ppb |
2019-02-19 | 530 DBP 1ST Q 19 | 34.6 ppb |
2019-02-19 | DBP 1ST Q 291 | 25.8 ppb |
2019-05-21 | 393 DBP 2ND Q 19 | 37.5 ppb |
2019-05-21 | 1047 DBP 2ND Q 1 | 37.4 ppb |
2019-05-21 | 523 DBP 2ND Q 19 | 29.3 ppb |
2019-05-21 | 291 DBP 2ND Q 19 | 25.5 ppb |
2019-05-21 | 391 DBP 2ND Q 19 | 41.8 ppb |
2019-05-21 | 484 DBP 2ND Q 19 | 36.9 ppb |
2019-05-21 | 530 DBP 2ND Q 19 | 40.8 ppb |
2019-05-21 | 527 DBP 2ND Q 19 | 32.1 ppb |
2019-06-20 | 340 DBP 2ND Q 19 | 27.2 ppb |
2019-06-20 | 491 DBP 2ND Q 19 | 32.6 ppb |
2019-06-20 | 433 DBP 2ND Q 19 | 43.0 ppb |
2019-06-20 | 402 DBP 2ND Q 19 | 32.2 ppb |
2019-08-27 | 402 3RD Q 19 DBP | 66.1 ppb |
2019-08-27 | 484 3RD Q 19 DBP | 38.8 ppb |
2019-08-27 | 393 3RD Q 19 DBP | 78.3 ppb |
2019-08-27 | 340 3RD Q 19 DBP | 50.5 ppb |
2019-08-27 | 5223 3RD Q 19 DB | 55.7 ppb |
2019-08-27 | 530 3RD Q 19 DBP | 74.8 ppb |
2019-08-27 | 527 3RD Q 19 DBP | 66.2 ppb |
2019-08-27 | 1047 3RD Q 19 DB | 69.8 ppb |
2019-08-27 | 433 3RD Q 19 DBP | 69.4 ppb |
2019-08-27 | 391 3RD Q 19 | 77.8 ppb |
2019-08-27 | 491 3RD Q 19 DBP | 55.5 ppb |
2019-08-27 | 291 3RD Q 19 DBP | 71.8 ppb |
2019-11-19 | 393 DBP 4TH Q | 44.7 ppb |
2019-11-19 | 402 4TH Q 2019 D | 32.0 ppb |
2019-11-19 | 527 4TH Q 19 DBP | 43.7 ppb |
2019-11-19 | 340 4TH Q DBP | 31.4 ppb |
2019-11-19 | 433 4TH Q 2019 D | 45.5 ppb |
2019-11-19 | 484 4TH Q 19 DBP | 25.4 ppb |
2019-11-19 | 530 4TH Q 19 DBP | 55.0 ppb |
2019-11-19 | 1047 4TH Q 19 DB | 51.0 ppb |
2019-11-19 | 391 DBP 4TH Q | 47.5 ppb |
2019-11-19 | 291 DBP 4TH Q | 35.9 ppb |
2019-11-19 | 523 4TH Q 19 DBP | 14.0 ppb |
2019-11-19 | 491 4TH Q 19 DBP | 39.4 ppb |