Total trihalomethanes (TTHMs)
White Plains 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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | 29.3 ppb | 32 | 32 | 14.0 ppb - 44.0 ppb |
2015 | 26.6 ppb | 31 | 31 | 20.0 ppb - 35.0 ppb |
2016 | 30.1 ppb | 32 | 32 | 20.0 ppb - 41.0 ppb |
2017 | 25.4 ppb | 32 | 32 | 17.0 ppb - 34.0 ppb |
2018 | 32.2 ppb | 32 | 32 | 22.0 ppb - 49.0 ppb |
2019 | 33.8 ppb | 31 | 31 | 24.0 ppb - 49.0 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 |
---|---|---|
2014-01-16 | 1401822-003DBP | 21.0 ppb |
2014-01-16 | 1401822-001DBP | 15.0 ppb |
2014-01-16 | 1401822-002DBP | 14.0 ppb |
2014-01-16 | 1401822-005DBP | 35.0 ppb |
2014-01-16 | 1401822-007DBP | 27.0 ppb |
2014-01-16 | 1401822-006DBP | 23.4 ppb |
2014-01-16 | 1401822-008DBP | 24.2 ppb |
2014-01-16 | 1401822-004DBP | 22.6 ppb |
2014-04-15 | 20140416886DBP | 27.0 ppb |
2014-04-15 | 201404160881DBP | 33.0 ppb |
2014-04-15 | 201404160883DBP | 30.0 ppb |
2014-04-15 | 20140416887DBP | 31.0 ppb |
2014-04-15 | 201404160882DBP | 31.0 ppb |
2014-04-15 | 201404160885DBP | 37.0 ppb |
2014-04-15 | 20140416888DBP | 33.0 ppb |
2014-04-15 | 201404160884DBP | 31.0 ppb |
2014-07-17 | 201407220320DBP | 20.0 ppb |
2014-07-17 | 201407220321DBP | 30.0 ppb |
2014-07-17 | 201407220319DBP | 22.0 ppb |
2014-07-17 | 201407220326DBP | 33.0 ppb |
2014-07-17 | 201407330324DBP | 30.0 ppb |
2014-07-17 | 201407220322DBP | 26.0 ppb |
2014-07-17 | 201407220325DBP | 35.0 ppb |
2014-07-17 | 20140722323DBP | 31.0 ppb |
2014-10-16 | 201410170209 DBP | 32.0 ppb |
2014-10-16 | 201410170207 DBP | 34.0 ppb |
2014-10-16 | 201410170210 DBP | 36.0 ppb |
2014-10-16 | 201410170205 DBP | 28.0 ppb |
2014-10-16 | 201410170204 DBP | 30.0 ppb |
2014-10-16 | 201410170208 DBP | 44.0 ppb |
2014-10-16 | 201410170211 DBP | 33.0 ppb |
2014-10-16 | 201410170206 DBP | 37.0 ppb |
2015-01-15 | 201501160214 DBP | 21.0 ppb |
2015-01-15 | 201501160215 DBP | 35.0 ppb |
2015-01-15 | 201501160219 DBP | 25.0 ppb |
2015-01-15 | 201501160218 DBP | 25.0 ppb |
2015-01-15 | 201501160213 DBP | 25.0 ppb |
2015-01-15 | 201501160216 DBP | 25.0 ppb |
2015-01-15 | 201501160217 DBP | 28.0 ppb |
2015-01-15 | 201501160220 DBP | 26.0 ppb |
2015-04-16 | DBP 5 | 30.0 ppb |
2015-04-16 | DBP 4 | 28.0 ppb |
2015-04-16 | DBP 6 | 28.0 ppb |
2015-04-16 | DBP 2 | 21.0 ppb |
2015-04-16 | DBP 1 | 31.0 ppb |
2015-04-16 | DBP 3 | 29.0 ppb |
2015-04-16 | DBP 8 | 24.0 ppb |
2015-04-16 | DBP 7 | 30.0 ppb |
2015-07-16 | 201505160085 DBP | 31.0 ppb |
2015-07-16 | 201505160084 DBP | 34.0 ppb |
2015-07-16 | 201505160078 DBP | 24.0 ppb |
2015-07-16 | 201505160082 DBP | 28.0 ppb |
2015-07-16 | 201505160080 DBP | 26.0 ppb |
2015-07-16 | 201505160079 DBP | 21.0 ppb |
2015-07-16 | 201502160083 DBP | 27.0 ppb |
2015-10-15 | 201508160046 DBP | 30.0 ppb |
2015-10-15 | 201508160040 DBP | 20.0 ppb |
2015-10-15 | 201508160043 DBP | 29.0 ppb |
2015-10-15 | 201506160039 DBP | 21.0 ppb |
2015-10-15 | 201508160044 DBP | 24.0 ppb |
2015-10-15 | 201508160042 DBP | 26.0 ppb |
2015-10-15 | 201508160045 DBP | 26.0 ppb |
2015-10-15 | 201508160041 DBP | 26.0 ppb |
2016-01-14 | 201511150041 DBP | 29.0 ppb |
2016-01-14 | 201511150042 DBP | 27.0 ppb |
2016-01-14 | 201511150044 DBP | 26.0 ppb |
2016-01-14 | 201511150043 DBP | 27.0 ppb |
2016-01-14 | 201511150046 DBP | 29.0 ppb |
2016-01-14 | 201511150039 | 21.0 ppb |
2016-01-14 | 201511150045 DBP | 33.0 ppb |
2016-01-14 | 201511150040 DBP | 21.0 ppb |
2016-04-14 | 201602140041 DBP | 28.0 ppb |
2016-04-14 | 201602140037 DBP | 28.0 ppb |
2016-04-14 | 201602140039 DBP | 28.0 ppb |
2016-04-14 | 201602140035 DBP | 23.0 ppb |
2016-04-14 | 201602140036 DBP | 29.0 ppb |
2016-04-14 | 201602140040 DBP | 33.0 ppb |
2016-04-14 | 201602140038 DBP | 30.0 ppb |
2016-04-14 | 201602140034 DBP | 21.0 ppb |
2016-07-14 | 201605160036 DBP | 20.0 ppb |
2016-07-14 | 201605160037 DBP | 31.0 ppb |
2016-07-14 | 201605160038 DBP | 33.0 ppb |
2016-07-14 | 201605160040 DBP | 35.0 ppb |
2016-07-14 | 201605160039 DBP | 36.0 ppb |
2016-07-14 | 201605160042 DBP | 41.0 ppb |
2016-07-14 | 201605160035 DBP | 26.0 ppb |
2016-07-14 | 201605160041 DBP | 32.0 ppb |
2016-10-13 | 201610140272 DBP | 28.0 ppb |
2016-10-13 | 201610140275 DBP | 39.0 ppb |
2016-10-13 | 201610140277 DBP | 36.0 ppb |
2016-10-13 | 201610140271 DBP | 30.0 ppb |
2016-10-13 | 201610140276 DBP | 37.0 ppb |
2016-10-13 | 201610140273 DBP | 30.0 ppb |
2016-10-13 | 201610140274 DBP | 36.0 ppb |
2016-10-13 | 201610140278 DBP | 41.0 ppb |
2017-01-12 | 201701130573 DBP | 30.0 ppb |
2017-01-12 | 201701130575 DBP | 32.0 ppb |
2017-01-12 | 20101130569 DBP | 17.0 ppb |
2017-01-12 | 201701130574 DBP | 26.0 ppb |
2017-01-12 | 201701130576 DBP | 29.0 ppb |
2017-01-12 | 201401130571 DBP | 24.0 ppb |
2017-01-12 | 201701130572 DBP | 25.0 ppb |
2017-01-12 | 201701130570 DBP | 19.0 ppb |
2017-04-13 | 201704140311-DBP | 21.0 ppb |
2017-04-13 | 201704140316-DBP | 27.0 ppb |
2017-04-13 | 201704140318-DBP | 28.0 ppb |
2017-04-13 | 201704140312-DBP | 21.0 ppb |
2017-04-13 | 201704140314-DBP | 30.0 ppb |
2017-04-13 | 201704140317-DBP | 29.0 ppb |
2017-04-13 | 201704140313-DBP | 29.0 ppb |
2017-04-13 | 201704140315-DBP | 28.0 ppb |
2017-07-20 | 201705160219-DBP | 22.0 ppb |
2017-07-20 | 201705160223-DBP | 24.0 ppb |
2017-07-20 | 201705160222-DBP | 30.0 ppb |
2017-07-20 | 201705160225-DBP | 28.0 ppb |
2017-07-20 | 201705160226-DBP | 24.0 ppb |
2017-07-20 | 201705160224-DBP | 21.0 ppb |
2017-07-20 | 201705160220-DBP | 19.0 ppb |
2017-07-20 | 201705160221-DBP | 21.0 ppb |
2017-10-19 | 201708160156-DBP | 22.0 ppb |
2017-10-19 | 201708160152-DBP | 22.0 ppb |
2017-10-19 | 201708160155-DBP | 34.0 ppb |
2017-10-19 | 201708160153-DBP | 28.0 ppb |
2017-10-19 | 201708160157-DBP | 27.0 ppb |
2017-10-19 | 201708160158-DBP | 27.0 ppb |
2017-10-19 | 201708160151-DBP | 23.0 ppb |
2017-10-19 | 201708160154-DBP | 27.0 ppb |
2018-01-18 | 201801190612-DBP | 23.0 ppb |
2018-01-18 | 201801190616-DBP | 26.0 ppb |
2018-01-18 | 201801190614-DBP | 26.0 ppb |
2018-01-18 | 201801190613-DBP | 27.0 ppb |
2018-01-18 | 201801190617-DBP | 28.0 ppb |
2018-01-18 | 201801190618-DBP | 28.0 ppb |
2018-01-18 | 201801190611-DBP | 22.0 ppb |
2018-01-18 | 201801190615-DBP | 29.0 ppb |
2018-04-17 | 201802130177-DBP | 35.0 ppb |
2018-04-17 | 201802130180-DBP | 35.0 ppb |
2018-04-17 | 201802130175-DBP | 26.0 ppb |
2018-04-17 | 201802130176-DBP | 26.0 ppb |
2018-04-17 | 201802130178-DBP | 36.0 ppb |
2018-04-17 | 201802130181-DBP | 41.0 ppb |
2018-04-17 | 201802130179-DBP | 39.0 ppb |
2018-04-17 | 201802130182-DBP | 41.0 ppb |
2018-07-17 | 201805160173-DBP | 30.0 ppb |
2018-07-17 | 201805160176-DBP | 39.0 ppb |
2018-07-17 | 201805160177-DBP | 33.0 ppb |
2018-07-17 | 201805160178-DBP | 33.0 ppb |
2018-07-17 | 201805160175-DBP | 32.0 ppb |
2018-07-17 | 201805160172-DBP | 26.0 ppb |
2018-07-17 | 201805160179-DBP | 36.0 ppb |
2018-07-17 | 201805160174-DBP | 24.0 ppb |
2018-10-19 | 201810170153-DBP | 25.0 ppb |
2018-10-19 | 201810170154-DBP | 41.0 ppb |
2018-10-19 | 201810170158-DBP | 36.0 ppb |
2018-10-19 | 201810170156-DBP | 49.0 ppb |
2018-10-19 | 201810170155-DBP | 37.0 ppb |
2018-10-19 | 201810170157-DBP | 38.0 ppb |
2018-10-19 | 201810170159-DBP | 38.0 ppb |
2018-10-19 | 201810170152-DBP | 26.0 ppb |
2019-01-16 | 201901170539-DBP | 45.0 ppb |
2019-01-16 | 201901170544-DBP | 42.0 ppb |
2019-01-16 | 201901170538-DBP | 30.0 ppb |
2019-01-16 | 201901170541-DBP | 49.0 ppb |
2019-01-16 | 201901170542-DBP | 42.0 ppb |
2019-01-16 | 201901170543-DBP | 42.0 ppb |
2019-01-16 | 201901170537-DBP | 28.0 ppb |
2019-01-16 | 201901170540-DBP | 40.0 ppb |
2019-04-17 | 201904110697-DBP | 44.0 ppb |
2019-04-17 | 201904110696-DBP | 38.0 ppb |
2019-04-17 | 201904110698-DBP | 36.0 ppb |
2019-04-17 | 201904110699-DBP | 34.0 ppb |
2019-04-17 | 201904110694-DBP | 28.0 ppb |
2019-04-17 | 201904110693-DBP | 27.0 ppb |
2019-04-17 | 201904110700-DBP | 37.0 ppb |
2019-04-17 | 201904110695-DBP | 42.0 ppb |
2019-07-17 | 201907180326-DBP | 29.0 ppb |
2019-07-17 | 201907180327-DBP | 31.0 ppb |
2019-07-17 | 201907180323-DBP | 28.0 ppb |
2019-07-17 | 201907180325-DBP | 32.0 ppb |
2019-07-17 | 201907180328-DBP | 27.0 ppb |
2019-07-17 | 201907180321-DBP | 26.0 ppb |
2019-07-17 | 201907180322-DBP | 24.0 ppb |
2019-10-16 | 201910180397-DBP | 35.0 ppb |
2019-10-16 | 201910180393-DBP | 32.0 ppb |
2019-10-16 | 201910180392-DBP | 32.0 ppb |
2019-10-16 | 201910180396-DBP | 31.0 ppb |
2019-10-16 | 201910180394-DBP | 31.0 ppb |
2019-10-16 | 201910180395-DBP | 30.0 ppb |
2019-10-16 | 201910180390-DBP | 28.0 ppb |
2019-10-16 | 201910180391-DBP | 29.0 ppb |