Know Your Environment. Protect Your Health.

Total trihalomethanes (TTHMs)

Baton Rouge Water Company

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.

 

132

Samples

0

Samples exceeding legal limit (MCL)

94

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20181.42 ppb3220ND - 5.50 ppb
20191.64 ppb3218ND - 6.90 ppb
20201.14 ppb2014ND - 5.60 ppb
20211.43 ppb1612ND - 6.50 ppb
20222.26 ppb16160.510 ppb - 7.30 ppb
20232.03 ppb1614ND - 6.40 ppb

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

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
2018-01-12353683490011.10 ppb
2018-01-12353683490020.600 ppb
2018-01-12353683490030.460 ppb
2018-01-12353683490045.30 ppb
2018-01-12353683490011.10 ppb
2018-01-12353683490020.600 ppb
2018-01-12353683490030.460 ppb
2018-01-12353683490045.30 ppb
2018-04-13353861440011.50 ppb
2018-04-1335386144002ND
2018-04-1335386144003ND
2018-04-1335386144004ND
2018-04-13353861440011.50 ppb
2018-04-1335386144002ND
2018-04-1335386144003ND
2018-04-1335386144004ND
2018-07-06354026090010.900 ppb
2018-07-0635402609002ND
2018-07-06354026090030.560 ppb
2018-07-06354026090045.50 ppb
2018-07-06354026090010.900 ppb
2018-07-0635402609002ND
2018-07-06354026090030.560 ppb
2018-07-06354026090045.50 ppb
2018-10-12354240300011.50 ppb
2018-10-1235424030002ND
2018-10-1235424030003ND
2018-10-12354240300045.30 ppb
2018-10-12354240300011.50 ppb
2018-10-1235424030002ND
2018-10-1235424030003ND
2018-10-12354240300045.30 ppb
2019-01-17354431630011.20 ppb
2019-01-1735443163002ND
2019-01-1735443163003ND
2019-01-17354431630046.90 ppb
2019-01-17354431630011.20 ppb
2019-01-1735443163002ND
2019-01-1735443163003ND
2019-01-17354431630046.90 ppb
2019-04-0835460486001ND
2019-04-0835460486002ND
2019-04-0835460486003ND
2019-04-08354604860045.10 ppb
2019-04-0835460486001ND
2019-04-0835460486002ND
2019-04-0835460486003ND
2019-04-08354604860045.10 ppb
2019-07-18354835350010.520 ppb
2019-07-18354835350020.420 ppb
2019-07-18354835350030.510 ppb
2019-07-18354835350045.50 ppb
2019-07-18354835350010.520 ppb
2019-07-18354835350020.420 ppb
2019-07-18354835350030.510 ppb
2019-07-18354835350045.50 ppb
2019-10-18355062380010.740 ppb
2019-10-1835506238002ND
2019-10-1835506238003ND
2019-10-18355062380045.30 ppb
2019-10-18355062380010.740 ppb
2019-10-1835506238002ND
2019-10-1835506238003ND
2019-10-18355062380045.30 ppb
2020-01-17355251880010.920 ppb
2020-01-1735525188002ND
2020-01-17355251880030.560 ppb
2020-01-1735525188004ND
2020-04-17355445950015.10 ppb
2020-04-17355445950020.510 ppb
2020-04-17355445950030.620 ppb
2020-04-17355445950044.60 ppb
2020-07-24355657140010.320 ppb
2020-07-24355657140020.750 ppb
2020-07-24355657140030.470 ppb
2020-07-24355657140040.430 ppb
2020-07-24B2003696-001ND
2020-07-24B2003696-002ND
2020-07-24B2003696-003ND
2020-07-24B2003696-004ND
2020-10-16355856730012.00 ppb
2020-10-16355856730020.400 ppb
2020-10-16355856730030.450 ppb
2020-10-16355856730045.60 ppb
2021-01-08356034860011.40 ppb
2021-01-0835603486002ND
2021-01-0835603486003ND
2021-01-0835603486004ND
2021-04-16356268130011.80 ppb
2021-04-16356268130020.990 ppb
2021-04-16356268130030.830 ppb
2021-04-16356268130040.430 ppb
2021-07-16356485750011.30 ppb
2021-07-16356485750020.610 ppb
2021-07-1635648575003ND
2021-07-16356485750045.40 ppb
2021-10-14356712520012.00 ppb
2021-10-14356712520020.780 ppb
2021-10-14356712520030.760 ppb
2021-10-14356712520046.50 ppb
2022-01-12356900340010.880 ppb
2022-01-12356900340025.80 ppb
2022-01-12356900340030.600 ppb
2022-01-12356900340040.630 ppb
2022-04-07357095600011.80 ppb
2022-04-07357095600020.540 ppb
2022-04-07357095600030.610 ppb
2022-04-07357095600047.30 ppb
2022-07-07357301280010.710 ppb
2022-07-07357301280020.700 ppb
2022-07-07357301300011.20 ppb
2022-07-07357301300027.10 ppb
2022-10-13357537790010.740 ppb
2022-10-13357537790026.40 ppb
2022-10-13357537790030.570 ppb
2022-10-13357537790040.510 ppb
2023-01-11357725260011.20 ppb
2023-01-11357725260024.80 ppb
2023-01-11357725260030.550 ppb
2023-01-11357725260040.580 ppb
2023-04-13357926650011.90 ppb
2023-04-13357926650026.40 ppb
2023-04-13357926650030.720 ppb
2023-04-13357926650040.580 ppb
2023-07-12358131460010.830 ppb
2023-07-12358131460026.30 ppb
2023-07-12358132540010.600 ppb
2023-07-12358132540020.790 ppb
2023-10-12358343960036.40 ppb
2023-10-1235834396004ND
2023-10-12358344320010.850 ppb
2023-10-1235834432002ND