Total trihalomethanes (TTHMs)
Dunkirk City and Area
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 |
---|---|---|---|---|
2013 | N/A | 0 | 0 | N/A |
2014 | 39.6 ppb | 20 | 20 | 26.3 ppb - 77.8 ppb |
2015 | 21.0 ppb | 20 | 20 | 10.2 ppb - 38.4 ppb |
2016 | 34.9 ppb | 16 | 16 | 19.3 ppb - 53.9 ppb |
2017 | 35.8 ppb | 16 | 16 | 14.0 ppb - 74.2 ppb |
2018 | 30.3 ppb | 17 | 17 | 13.4 ppb - 53.0 ppb |
2019 | 31.3 ppb | 16 | 16 | 13.0 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 |
---|---|---|
2014-02-06 | STAGE2 ST. COL F | 64.5 ppb |
2014-02-06 | STAGE2LAFAYETTE | 77.8 ppb |
2014-05-01 | MAY14 DUNKIRK SA | 45.5 ppb |
2014-05-01 | MAY14 DUNKIRK SA | 34.2 ppb |
2014-08-21 | AUG 2014 LAFAYET | 40.5 ppb |
2014-08-21 | AUG14 LAFAYETT T | 40.5 ppb |
2014-08-21 | AUG14 ST COL. TO | 49.8 ppb |
2014-08-21 | AUG 2014 DON FRA | 34.2 ppb |
2014-08-21 | AUG 2014 HOYT | 35.7 ppb |
2014-08-21 | AUG 2014 ST COLU | 49.8 ppb |
2014-08-28 | AUG14 HOYT TOTAL | 35.7 ppb |
2014-08-28 | AUG14 DONFRAME T | 34.3 ppb |
2014-11-05 | NOV14STCOLUMBAN | 37.1 ppb |
2014-11-05 | NOV14 DON FRAME | 30.8 ppb |
2014-11-05 | NOV14 DONFRAME T | 30.8 ppb |
2014-11-05 | NOV14 ST. COLUMB | 37.1 ppb |
2014-11-06 | NOV14LAFAYETTE T | 30.4 ppb |
2014-11-06 | NOV14 344 HOYT | 26.3 ppb |
2014-11-06 | NOV14 HOYT TOTAL | 26.3 ppb |
2014-11-06 | NOV14 17 LAFAYET | 30.4 ppb |
2015-02-04 | FEB15 HOYT TOTAL | 13.4 ppb |
2015-02-04 | FEB15COLUMBANS T | 21.6 ppb |
2015-02-04 | FEB15 4737 WILLO | 17.8 ppb |
2015-02-04 | FEB15 ST. COLUMB | 21.6 ppb |
2015-02-04 | FEB15 WILLOW TOT | 17.8 ppb |
2015-02-04 | FEB15 LAYFAYETTT | 15.1 ppb |
2015-02-04 | FEB15 344 HOYT | 13.4 ppb |
2015-02-04 | FEB15 LAFAYETTE | 15.1 ppb |
2015-05-14 | MAY15 ST. COLUMB | 16.0 ppb |
2015-05-14 | MAY15 LAFAYETTE | 20.2 ppb |
2015-05-14 | MAY15 WILLOW ROA | 10.2 ppb |
2015-05-14 | MAY15 HOYT ST | 10.7 ppb |
2015-08-06 | AUG15 344 HOYT | 38.4 ppb |
2015-08-06 | AUG15 17 LAFAYET | 35.2 ppb |
2015-08-06 | AUG15 ST. COLUMB | 35.5 ppb |
2015-08-06 | AUG15 4737 WILLO | 33.7 ppb |
2015-11-19 | NOV15 LAFAYETTE | 20.9 ppb |
2015-11-19 | NOV15 4737WILLOW | 17.5 ppb |
2015-11-19 | NOV15 HOYT ST | 19.5 ppb |
2015-11-19 | NOV15 ST COLUMBA | 27.2 ppb |
2016-02-23 | FEB16 JN ADAM | 22.4 ppb |
2016-02-23 | FEB16 334 HOYT | 21.2 ppb |
2016-02-23 | FEB16 ST. COLUMB | 28.2 ppb |
2016-02-23 | FEB16 17 LAFAYET | 19.3 ppb |
2016-05-10 | 2NDQT16 344 HOYT | 22.4 ppb |
2016-05-10 | 2NDQT16 JN ADAM | 27.8 ppb |
2016-05-10 | 2NDQT16 ST COLUM | 35.0 ppb |
2016-05-10 | 2NDQT16 17 LAFAY | 28.9 ppb |
2016-08-10 | AUG16 HOYT, DUNK | 47.0 ppb |
2016-08-10 | AUG16 ST COLUMBA | 53.9 ppb |
2016-08-10 | AUG16 JN ADAM DU | 52.5 ppb |
2016-08-10 | AUG16 LAFAYETTE | 51.4 ppb |
2016-11-02 | NOV16 JN ADAM | 40.9 ppb |
2016-11-02 | NOV16 17 LAFAYET | 33.6 ppb |
2016-11-02 | NOV16 344 HOYT | 29.8 ppb |
2016-11-02 | NOV16 ST COLUMBA | 43.6 ppb |
2017-02-08 | FEB17 ST. COLUMB | 26.0 ppb |
2017-02-08 | FEB17 17 LAFYETT | 20.6 ppb |
2017-02-08 | FEB17 344 HOYT | 14.0 ppb |
2017-02-08 | FEB17 JN ADAMS H | 24.3 ppb |
2017-05-03 | MAY17 344 HOYT | 21.2 ppb |
2017-05-03 | MAY17 ST COLULMB | 39.7 ppb |
2017-05-03 | MAY17 JN ADAMS | 37.2 ppb |
2017-05-03 | MAY17 LAFAYETTE | 40.0 ppb |
2017-08-09 | AUG17 JN ADAMS | 74.2 ppb |
2017-08-09 | AUG17 ST. COLUMB | 46.8 ppb |
2017-08-09 | AUG17 HOYT | 46.8 ppb |
2017-08-09 | AUG17 LAFAYETTE | 47.9 ppb |
2017-11-08 | NOV17 17 LAFEYET | 30.2 ppb |
2017-11-08 | NOV17 JN ADAM 20 | 37.0 ppb |
2017-11-08 | NOV17 344 HOYT | 24.3 ppb |
2017-11-08 | NOV17 ST. COLUMB | 42.0 ppb |
2018-02-13 | Q1DUNKIRK 2018 C | 27.5 ppb |
2018-02-13 | Q1DUNKIRK 2018 H | 13.4 ppb |
2018-02-13 | Q1DUNKIRK 2018 L | 26.0 ppb |
2018-02-13 | Q1DUNKIRK 2018 J | 25.0 ppb |
2018-05-08 | Q219 SENIOR CTR | 31.0 ppb |
2018-05-09 | Q2DUNKIRK 18 LAF | 28.0 ppb |
2018-05-09 | Q2DUNKIRK 18 HOY | 14.0 ppb |
2018-05-09 | Q2DUNKIRK 18 COL | 28.0 ppb |
2018-05-09 | Q2DUNKIRK 18 ADA | 31.0 ppb |
2018-08-15 | Q3DUNKIRK 18 ADA | 51.0 ppb |
2018-08-15 | Q3DUNKIRK 18 HOY | 51.0 ppb |
2018-08-15 | Q3DUNKIRK 18 ST | 51.0 ppb |
2018-08-15 | Q3DUNKIRK 18 LAF | 53.0 ppb |
2018-11-20 | Q4 18 HOYT DBPS | 17.7 ppb |
2018-11-20 | Q4 18 FISHERIES | 23.0 ppb |
2018-11-20 | Q4 18 SENIOR CTR | 18.1 ppb |
2018-11-20 | Q4 18 LAFAYETTE | 27.0 ppb |
2019-02-13 | Q1 19 FISHERIES | 22.0 ppb |
2019-02-13 | Q1 19 344 HOYT D | 14.1 ppb |
2019-02-13 | Q1 19 SENIOR CTR | 13.0 ppb |
2019-02-13 | Q1 19 LAFAYETTE | 18.7 ppb |
2019-05-08 | Q2 19 344 HOYT D | 29.0 ppb |
2019-05-08 | Q2 19 LAFAYETTE | 30.0 ppb |
2019-05-08 | Q2 19 SENIOR CTR | 31.0 ppb |
2019-05-08 | Q2 19 FISHERIES | 36.0 ppb |
2019-08-28 | Q3 19 LAFAYETTE | 49.5 ppb |
2019-08-28 | Q3 19 344 HOYT D | 48.5 ppb |
2019-08-28 | Q3 19 SENIOR CTR | 42.2 ppb |
2019-08-28 | Q3 19 FISHERIES | 44.6 ppb |
2019-11-13 | Q4 19 FISHERIES | 28.2 ppb |
2019-11-13 | Q4 19 SENIOR CTR | 28.2 ppb |
2019-11-13 | Q4 19 LAFAYETTE | 30.0 ppb |
2019-11-13 | Q4 19 344 HOYT D | 36.1 ppb |