2023/24: Minnipa (South Australia) Trihalomethanes
3/10/23: Minnipa (South Australia) Trihalomethanes 264ug/L (max), 175.75ug/L (av. 2023/24)
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/in
2023/24: Minnipa (South Australia) Bromoform
2023/24: Minnipa (South Australia) Bromoform 109ug/L (max), 66.25ug/L av.
WHO Bromoform Guideline 100ug/L. Bromoform is a Trihalomethane, which combined with Dibromochloromethane, Bromodichloromethane and Chloroform amount to Total Trihalomethanes. Trihalomethanes (combined) have an Australian Guideline of 250ug/L
Natural production of bromoform by phytoplankton and seaweeds in the ocean is thought to be its predominant source in the environment.[5] However, locally significant amounts of bromoform enter the environment formed as disinfection byproducts known as trihalomethanes when chlorine is added to drinking water to kill bacteria. It is somewhat soluble in water and readily evaporates into the air. Bromoform is the main trihalomethane produced in beachfront salt water swimming pools with concentrations as high as 1.2 ppm (parts per million). Concentrations in freshwater pools are 1000 times lower.[6] Occupational skin exposure limits are set at 0.5 ppm