Total trihalomethanes (TTHMs)
Syracuse City
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 29.8 ppb | 16 | 16 | 14.0 ppb - 52.0 ppb |
| 2015 | 31.8 ppb | 16 | 16 | 18.0 ppb - 45.0 ppb |
| 2016 | 32.1 ppb | 16 | 16 | 17.0 ppb - 47.0 ppb |
| 2017 | 34.4 ppb | 16 | 16 | 19.0 ppb - 64.0 ppb |
| 2018 | 32.6 ppb | 16 | 16 | 21.0 ppb - 47.0 ppb |
| 2019 | 32.7 ppb | 16 | 16 | 20.0 ppb - 49.5 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 |
|---|---|---|
| 2014-02-11 | 1Q2014 MAMA NANC | 14.0 ppb |
| 2014-02-11 | 1Q2014 MUZAK COR | 18.0 ppb |
| 2014-02-11 | 1Q2014 COLEMAN F | 18.0 ppb |
| 2014-02-11 | 1Q2014 MCCHESNEY | 14.4 ppb |
| 2014-05-13 | 2Q2014 MUZAK COR | 26.0 ppb |
| 2014-05-13 | 2Q2014 CANNON TR | 22.0 ppb |
| 2014-05-13 | 2Q2014 COLEMAN F | 25.0 ppb |
| 2014-05-13 | 2Q2014 MCCHESNEY | 23.0 ppb |
| 2014-08-12 | 3Q2014 MAMA NANC | 52.0 ppb |
| 2014-08-12 | 3Q2014 MUZAK COR | 45.0 ppb |
| 2014-08-12 | 3Q2014 COLEMAN F | 48.0 ppb |
| 2014-08-12 | 3Q2014 MCCHESNEY | 50.0 ppb |
| 2014-11-12 | 4Q2014 COLEMAN F | 31.0 ppb |
| 2014-11-12 | 4Q2014 MUZAK COR | 29.0 ppb |
| 2014-11-12 | 4Q2014 MCCHESNEY | 31.0 ppb |
| 2014-11-12 | 4Q2014 MAMA NANC | 31.0 ppb |
| 2015-02-11 | 1Q2015 MAMA NANC | 18.0 ppb |
| 2015-02-11 | 1Q2015 MCCHESNEY | 21.0 ppb |
| 2015-02-11 | 1Q2015 MUZAK COR | 25.0 ppb |
| 2015-02-11 | 1Q2015 COLEMAN F | 20.0 ppb |
| 2015-05-13 | 2Q2015 MAMA NANC | 24.0 ppb |
| 2015-05-13 | 2Q2015 MUZAK COR | 40.0 ppb |
| 2015-05-13 | 2Q2015 COLEMAN F | 31.0 ppb |
| 2015-05-13 | 2Q2015 MCCHESNEY | 27.0 ppb |
| 2015-08-11 | 3Q2015 MUZAK COR | 45.0 ppb |
| 2015-08-11 | 3Q2015 COLEMAN F | 44.0 ppb |
| 2015-08-11 | 3Q2015 MAMA NANC | 43.0 ppb |
| 2015-08-11 | 3Q2015 MCCHESNEY | 42.0 ppb |
| 2015-11-09 | 4Q2015 MAMA NANC | 27.0 ppb |
| 2015-11-09 | 4Q2015 MCCHESNEY | 30.0 ppb |
| 2015-11-09 | 4Q2015 MUZAK COR | 37.0 ppb |
| 2015-11-09 | 4Q2015 COLEMAN F | 34.0 ppb |
| 2016-02-09 | 1Q2016 MUZAK COR | 18.0 ppb |
| 2016-02-09 | 1Q2016 MAMA NANC | 17.0 ppb |
| 2016-02-09 | 1Q2016 MCCHESNEY | 17.0 ppb |
| 2016-02-09 | 1Q2016 COLEMAN F | 17.0 ppb |
| 2016-05-10 | 2Q2016 MAMA NANC | 26.0 ppb |
| 2016-05-10 | 2Q2016 MUZAK COR | 26.0 ppb |
| 2016-05-10 | 2Q2016 COLEMAN F | 24.0 ppb |
| 2016-05-10 | 2Q2016 MCCHESNEY | 23.0 ppb |
| 2016-08-11 | 3Q2016 MUZAK COR | 45.0 ppb |
| 2016-08-11 | 3Q2016 MCCHESNEY | 45.0 ppb |
| 2016-08-11 | 3Q2016 MAMA NANC | 47.0 ppb |
| 2016-08-11 | 3Q2016 COLEMAN F | 45.0 ppb |
| 2016-11-16 | 4Q2016 COLEMAN F | 39.0 ppb |
| 2016-11-16 | 4Q2016 MAMA NANC | 44.0 ppb |
| 2016-11-16 | 4Q2016 MCCHESNEY | 43.0 ppb |
| 2016-11-16 | 4Q2016 MUZAK COR | 38.0 ppb |
| 2017-02-16 | 1Q2017 MUZAK COR | 21.0 ppb |
| 2017-02-16 | 1Q2017 COLEMAN F | 23.0 ppb |
| 2017-02-16 | 1Q2017 MAMA NANC | 19.0 ppb |
| 2017-02-16 | 1Q2017 MCCHESNEY | 20.0 ppb |
| 2017-05-10 | 2Q2017 MAMA NANC | 25.0 ppb |
| 2017-05-10 | 2Q2017 MUZAK COR | 27.0 ppb |
| 2017-05-10 | 2Q2017 MCCHESNEY | 26.0 ppb |
| 2017-05-10 | 2Q2017 COLEMAN F | 29.0 ppb |
| 2017-08-16 | 3Q2017 MAMA NANC | 64.0 ppb |
| 2017-08-16 | 3Q2017 MCCHESNEY | 63.0 ppb |
| 2017-08-16 | 3Q2017 MUZAK COR | 54.0 ppb |
| 2017-08-16 | 3Q2017 COLEMAN F | 49.0 ppb |
| 2017-11-15 | 4Q2017 MAMA NANC | 33.0 ppb |
| 2017-11-15 | 4Q2017 COLEMAN F | 34.0 ppb |
| 2017-11-15 | 4Q2017 MUZAK COR | 33.0 ppb |
| 2017-11-15 | 4Q2017 MCCHESNEY | 30.0 ppb |
| 2018-02-23 | 1Q2018 MCCHESNEY | 22.0 ppb |
| 2018-02-23 | 1Q2018 COLEMAN F | 29.0 ppb |
| 2018-02-23 | 1Q2018 MUZAK COR | 29.0 ppb |
| 2018-02-23 | 1Q2018 MAMA NANC | 21.0 ppb |
| 2018-05-10 | 2Q2018 MAMA NANC | 24.0 ppb |
| 2018-05-10 | 2Q2018 COLEMANS | 31.0 ppb |
| 2018-05-10 | 2Q2018 MUZAK COR | 32.0 ppb |
| 2018-05-10 | 2Q2018 MCCHESNEY | 26.0 ppb |
| 2018-07-17 | 3Q2018 COLEMAN F | 37.0 ppb |
| 2018-07-17 | 3Q2018 MAMA NANC | 47.0 ppb |
| 2018-07-17 | 3Q2018 MCCHESNEY | 38.0 ppb |
| 2018-07-17 | 3Q2018 MUZAK COR | 37.0 ppb |
| 2018-10-17 | 4Q2018 COLEMAN F | 35.0 ppb |
| 2018-10-17 | 4Q2018 MCCHESNEY | 36.0 ppb |
| 2018-10-17 | 4Q2018 MUZAK COR | 35.0 ppb |
| 2018-10-17 | 4Q2018 MAMA NANC | 43.0 ppb |
| 2019-01-28 | 1Q2019 MOOD DARW | 26.0 ppb |
| 2019-01-28 | 1Q2019 MAMA NANC | 20.0 ppb |
| 2019-01-28 | 1Q2019 COLEMAN F | 22.0 ppb |
| 2019-01-28 | 1Q2019 MCCHESNEY | 22.0 ppb |
| 2019-04-18 | 2Q2019 MAMA NANC | 20.0 ppb |
| 2019-04-18 | 2Q2019 MCCHESNEY | 20.5 ppb |
| 2019-04-18 | 2Q2019 COLEMANS | 25.9 ppb |
| 2019-04-18 | 2Q2019 MOOD MEDI | 24.5 ppb |
| 2019-07-17 | 3Q2019 MAMA NANC | 48.1 ppb |
| 2019-07-17 | 3Q2019 MCCHESNEY | 42.0 ppb |
| 2019-07-17 | 3Q2019 COLEMANS | 47.3 ppb |
| 2019-07-17 | 3Q2019 MOOD DARW | 49.5 ppb |
| 2019-10-16 | 4Q2019 MCCHESNEY | 35.6 ppb |
| 2019-10-16 | 4Q2019 COLEMANS | 38.8 ppb |
| 2019-10-16 | 4Q2019 MAMA NANC | 42.9 ppb |
| 2019-10-16 | 4Q2019 MOOD DARW | 38.7 ppb |