2000/13: Lock (South Australia) – Trihalomethanes, Chloral Hydrate

Lock (South Australia)

Breaches to Australian Drinking Water Guidelines Levels Only

Nov 2000? Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 342 ug/L

16/01/2001  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 599 ug/L

26/03/2001  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 330 ug/L

22/01/2002  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 655 ug/L

20/03/2002  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 366 ug/L

28/05/2002  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 252 ug/L

18/12/2007  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 315 ug/L

18/12/2007  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 297 ug/L

15/01/2008  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 288 ug/L

12/02/2008  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 287 ug/L

17/06/2008  Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 270 ug/L

1/05/13 Lock Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 259 ug/L

28/08/13 Lock Lock  3 Railway Tce (SAW Depot) Trihalomethanes – Total 277 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: http://water.epa.gov/drink/contaminants/ind

Lock (South Australia) – Chloral Hydrate

1/6/10 Lock  Chloral Hydrate 25.8ug/L

26/6/12 Lock  Chloral Hydrate 32.5ug/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