Know Your Environment. Protect Your Health.

Total trihalomethanes (TTHMs)

City of Bogalusa Water System

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.

 

128

Samples

0

Samples exceeding legal limit (MCL)

118

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20182.04 ppb3230ND - 4.20 ppb
20191.99 ppb3226ND - 5.30 ppb
20201.71 ppb1615ND - 3.20 ppb
20212.24 ppb16161.02 ppb - 3.50 ppb
20222.70 ppb1615ND - 5.10 ppb
20232.96 ppb16160.940 ppb - 9.20 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
2018-01-12353684070012.80 ppb
2018-01-12353684070021.70 ppb
2018-01-12353684070030.800 ppb
2018-01-12353684070041.40 ppb
2018-01-12353684070012.80 ppb
2018-01-12353684070021.70 ppb
2018-01-12353684070030.800 ppb
2018-01-12353684070041.40 ppb
2018-04-05353846300012.20 ppb
2018-04-05353846300020.520 ppb
2018-04-05353846300032.90 ppb
2018-04-05353846300044.20 ppb
2018-04-05353846300012.20 ppb
2018-04-05353846300020.520 ppb
2018-04-05353846300032.90 ppb
2018-04-05353846300044.20 ppb
2018-07-05354025390012.60 ppb
2018-07-05354025390023.30 ppb
2018-07-05354025390033.50 ppb
2018-07-05354025390042.60 ppb
2018-07-05354025390012.60 ppb
2018-07-05354025390023.30 ppb
2018-07-05354025390033.50 ppb
2018-07-05354025390042.60 ppb
2018-10-04354225490011.70 ppb
2018-10-0435422549002ND
2018-10-04354225490031.10 ppb
2018-10-04354225490041.30 ppb
2018-10-04354225490011.70 ppb
2018-10-0435422549002ND
2018-10-04354225490031.10 ppb
2018-10-04354225490041.30 ppb
2019-01-11354418650012.50 ppb
2019-01-11354418650020.510 ppb
2019-01-11354418650032.60 ppb
2019-01-11354418650042.50 ppb
2019-01-11354418650012.50 ppb
2019-01-11354418650020.510 ppb
2019-01-11354418650032.60 ppb
2019-01-11354418650042.50 ppb
2019-04-05354599590011.60 ppb
2019-04-0535459959002ND
2019-04-05354599590031.30 ppb
2019-04-05354599590041.20 ppb
2019-04-05354599590011.60 ppb
2019-04-0535459959002ND
2019-04-05354599590031.30 ppb
2019-04-05354599590041.20 ppb
2019-07-19354836710013.00 ppb
2019-07-1935483671002ND
2019-07-19354836710032.70 ppb
2019-07-19354836710043.00 ppb
2019-07-19354836710013.00 ppb
2019-07-1935483671002ND
2019-07-19354836710032.70 ppb
2019-07-19354836710043.00 ppb
2019-10-04355028580015.30 ppb
2019-10-0435502858002ND
2019-10-04355028580033.00 ppb
2019-10-04355028580042.60 ppb
2019-10-04355028580015.30 ppb
2019-10-0435502858002ND
2019-10-04355028580033.00 ppb
2019-10-04355028580042.60 ppb
2020-01-09355234120010.880 ppb
2020-01-09355234120020.580 ppb
2020-01-09355234120031.40 ppb
2020-01-09355234120041.20 ppb
2020-04-03355414630012.50 ppb
2020-04-0335541463002ND
2020-04-03355414630032.80 ppb
2020-04-03355414630043.10 ppb
2020-07-10355623780011.50 ppb
2020-07-10355623780021.40 ppb
2020-07-10355623780031.40 ppb
2020-07-10355623780041.20 ppb
2020-10-02355820990012.20 ppb
2020-10-02355820990021.01 ppb
2020-10-02355820990033.00 ppb
2020-10-02355820990043.20 ppb
2021-01-08356034830011.90 ppb
2021-01-08356034830021.20 ppb
2021-01-08356034830033.50 ppb
2021-01-08356034830043.20 ppb
2021-04-09356250800012.60 ppb
2021-04-09356250800021.28 ppb
2021-04-09356250800033.40 ppb
2021-04-09356250800042.14 ppb
2021-07-09356463690012.00 ppb
2021-07-09356463690021.02 ppb
2021-07-09356463690032.20 ppb
2021-07-09356463690042.00 ppb
2021-10-01356687370013.00 ppb
2021-10-01356687370021.22 ppb
2021-10-01356687370033.50 ppb
2021-10-01356687370041.64 ppb
2022-01-07356892150011.70 ppb
2022-01-0735689215002ND
2022-01-07356892150032.60 ppb
2022-01-07356892150042.00 ppb
2022-04-01357074970012.00 ppb
2022-04-01357074970020.630 ppb
2022-04-01357074970033.30 ppb
2022-04-01357074970043.20 ppb
2022-07-07357310640014.80 ppb
2022-07-07357310640025.10 ppb
2022-07-07357310640035.00 ppb
2022-07-07357310640044.30 ppb
2022-10-06357514580012.20 ppb
2022-10-06357514580020.500 ppb
2022-10-06357514580033.20 ppb
2022-10-06357514580042.70 ppb
2023-01-06357709680011.55 ppb
2023-01-06357709680020.940 ppb
2023-01-06357709680033.00 ppb
2023-01-06357709680041.62 ppb
2023-04-05357909120012.00 ppb
2023-04-05357909120020.990 ppb
2023-04-05357909120033.10 ppb
2023-04-05357909120042.10 ppb
2023-07-14358134410013.30 ppb
2023-07-14358134410021.28 ppb
2023-07-14358134410033.50 ppb
2023-07-14358134410043.00 ppb
2023-10-06358329610019.20 ppb
2023-10-06358329610025.60 ppb
2023-10-06358329610033.10 ppb
2023-10-06358329610043.10 ppb