2010/12 + 2017/23: Monteith (South Australia) – Trihalomethanes, Bromodichloromethane, Chloral Hydrate

Monteith (South Australia) – Trihalomethanes

Breaches to Australian Drinking Water Guidelines Levels Only

3/5/2017 Monteith Bells Road Trihalomethanes – Total 289ug/L

30/3/22: Monteith Trihalomethanes 30/3/22 (max) 152.1ug/L (av. 2021/22)

Trihalomethanes Australian Guideline Level 250μg/L (0.25mg/L)

Why and how are THMs formed?
“When chlorine is added to water with organic material, such as algae, river weeds, and decaying leaves, THMs are formed. Residual chlorine molecules react with this harmless organic material to form a group of chlorinated chemical compounds, THMs. They are tasteless and odourless, but harmful and potentially toxic. The quantity of by-products formed is determined by several factors, such as the amount and type of organic material present in water, temperature, pH, chlorine dosage, contact time available for chlorine, and bromide concentration in the water. The organic matter in water mainly consists of a) humic substance, which is the organic portion of soil that remains after prolonged microbial decomposition formed by the decay of leaves, wood, and other vegetable matter; and b) fulvic acid, which is a water soluble substance of low molecular weight that is derived from humus”. Source: https://water.epa.gov/drink/contaminan

Monteith (South Australia) – Bromodichloromethane

2018/19: Monteith (South Australia) Bromodichloromethane 66ug/L (max), 46.8ug/L (av.)

2022/23: Monteith (South Australia) Bromodichloromethane 96ug/L (max), 58.05ug/L (av.)

WHO Guideline level BDCM: 60ug/L (Australian Guideline for BDCM is included in the combined total of BDCM, Chloroform, Dibromochloromethane and Bromoform. THM guideline is 250ug/L)

“Carcinogenicity : Bromodichloromethane is reasonably anticipated to be a human carcinogen based on sufficient evidence of carcinogenicity from studies in experimental animals.
Cancer Studies in Experimental Animals: Oral exposure to bromodichloromethane caused tumors at several different tissue sites in mice and rats. Administration of bromodichloromethane by stomach tube caused benign and malignant kidney tumors (tubular-cell adenoma and adenocarcinoma) in male mice and in rats of both sexes, benign and
malignant liver tumors (hepatocellular adenoma and carcinoma) in female mice, and benign and malignant colon tumors (adenomatous polyps and adenocarcinoma) in rats of both sexes (NTP 1987, ATSDR 1989, IARC 1991, 1999).

Since bromodichloromethane was listed in the Sixth Annual Report on Carcinogens, additional studies in rats have been identified. Administration of bromodichloromethane in the drinking water increased the combined incidence of benign and malignant liver tumors (hepatocellular adenoma or carcinoma) in males (George et al. 2002) and caused benign liver tumors (hepatocellular adenoma) in females (Tumasonis et al. 1987).

Cancer Studies in Humans
The data available from epidemiological studies are inadequate to evaluate the relationship between human cancer and exposure specifically to bromodichloromethane. Several epidemiological studies indicated a possible association between ingestion of chlorinated drinking water (which typically contains bromodichloromethane) and increased risk of
cancer in humans, but these studies could not provide information on whether any observed effects were due to bromodichloromethane or to one or more of the hundreds of other disinfection by-products also present in chlorinated water (ATSDR 1989).” (1)

Monteith (South Australia) – Chloral Hydrate

30/6/10 Monteith  Chloral Hydrate 21.8ug/L

12/10/11 Monteith  Chloral Hydrate 21.6ug/L

10/11/11 Monteith  Chloral Hydrate 31.2ug/L

6/12/11 Monteith  Chloral Hydrate 31.9ug/L

11/1/12 Monteith  Chloral Hydrate 25.7ug/L

½/12 Monteith  Chloral Hydrate 20ug/L

1/3/12 Monteith  Chloral Hydrate 38.4ug/L

29/3/12 Monteith  Chloral Hydrate 38.3ug/L

26/4/12 Monteith  Chloral Hydrate 38.5ug/L

23/5/12 Monteith  Chloral Hydrate 34.4ug/L

20/6/12 Monteith  Chloral Hydrate 29.8ug/L

Chloral hydrate is a disinfection by-product, arising from chlorination of water containing naturally occurring organic material (NOM). Chloral hydrate is a sedative and hypnotic drug. Long-term use of chloral hydrate is associated with a rapid development of tolerance to its effects and possible addiction as well as adverse effects including rashes, gastric
discomfort and severe renal, cardiac and hepatic failure.

2004 Australian Drinking Water Guideline: Trichloroacetaldehyde (chloral hydrate): 0.02mg/L

2011 Australian Drinking Water Guideline: Trichloroacetaldehyde (chloral hydrate): 0.1mg/L