2000/12 & 2022: Kimba (South Australia) – Trihalomethanes, Chloral Hydrate, Total Haloacetic Acids

Kimba (South Australia)

Breaches to Australian Drinking Water Guidelines Levels Only

22/02/2000 Kimba CT  High St (SAW Depot) Trihalomethanes – Total 305 ug/L

20/02/2001 Kimba CT  High St (SAW Depot) Trihalomethanes – Total 535 ug/L

17/04/2001 Kimba CT  High St (SAW Depot) Trihalomethanes – Total 722 ug/L

18/12/2001 Kimba CT  High St (SAW Depot) Trihalomethanes – Total 290 ug/L

16/04/2002 Kimba CT  High St (SAW Depot) Trihalomethanes – Total 263 ug/L

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/contaminants/ind

Kimba (South Australia) – Chloral Hydrate

14/12/10 Kimba  Chloral Hydrate 27.4ug/L

10/1/11 Kimba  Chloral Hydrate 23.6ug/L

8/2/11 Kimba  Chloral Hydrate 27.2ug/L

7/3/11 Kimba  Chloral Hydrate 32.7ug/L

4/4/11 Kimba  Chloral Hydrate 23.8ug/L

10/1/12 Kimba  Chloral Hydrate 21.5ug/L

30/4/12 Kimba  Chloral Hydrate 23.4ug/L

28/5/12 Kimba  Chloral Hydrate 22.6ug/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

Kimba (South Australia) – Total Haloacetic Acids

17/5/22: Kimba (South Australia) Total Haloacetic Acid (HAA 9)131ug/L (max) 120.5ug/L (av.)

“Chloroacetic acids are produced in drinking water as by-products of the reaction between chlorine and naturally occurring humic and fulvic acids. Concentrations reported overseas range up to 0.16mg/L and are typically about half the chloroform concentration. The chloroacetic acids are used commercially as reagents or intermediates in the preparation of a wide variety of chemicals. Monochloroacetic acid can be used as a pre-emergent herbicide, dichloroacetic acid as an ingredient in some pharmaceutical products, and trichloroacetic acid as a herbicide, soil sterilant and antiseptic.” Australian Drinking Water Guidelines – National Health and Medical Research Council