2010: Lower Lakes (South Australia) – NDMA, Chlorine Total

Lower Lakes (South Australia) – NDMA

The Highest NDMA levels recorded in South Australia 2007-12 were at Keith 140ng/L 17/11/10 and Lower Lakes 130ng/L 24/2/10 and 17/11/10.

Australian Drinking Water Guideline NDMA: 100ng/L (0.1ug/L)

N-Nitrosodimethylamine (NDMA) can be created through water treatment via cholorination or chloramination or organic nitrogen containing waste water. NDMA is highly toxic and a suspected carcinogen. It was widely discovered in groundwater in California in the late 1970’s as a by-product unsymmetrical dimethylhydrazine (UDMH), which is a component of rocket fuel that requires NDMA for its synthesis. Eight other nitrosamines of interest in drinking and
recycled water are: N-nitrosodiethylamine (MDEA) , N-nitrosodi-n-propylamine (NDPA) , N-nitrosodi-n-butylamine (NDBA) , N-nitrosomethylethylamine (NMEA) , N-nitrosomorpholine (Nmor) , N-nitrosopiperidine (Npip), Nnitrosopyrrolidine (NPyr) and N-nitrosodiphenylamine ((NDPha) .

“More recently, rubber components such as valves and joiners/0-rings that are used in treatment plant pumps and in distribution systems have been found to leach significant levels of nitrosamines into the water supply (Morran etal., 2011). .. In Australia, chloramination is widely practiced and in South Australia the South Australian Water Corporation implemented a routine monitoring program for NDMA in four systems in 2007. From these results it is
clear that the levels in the distribution system vary considerably with time, indicating a seasonal influence due to variations in detention time controlled by demand. There was also evidence of a strong influence of water quality during a period of high flow, colour and turbidity in the river feeding the treatment plants. However, the average concentration of NDMA of more than 750 samples analysed from 2007 to present was low, < 20ng/L. Knight et at. (2011) recently reported nitrosamine data from five drinking water treatment plants in South-East Queensland. Three
of these plants practice chloramination, one uses chlorination, and the other a combination of ozone and chlorine fordisinfection. ” Source: NDMA ATTRACTING INTERNATIONAL ATTENTION The latest news on nitrosamines G Newcombe, J Morran, J Culbert

Meningie (South Australia) – Chlorine Total

Highest SA Water Chlorine Free Levels 2000-12: 31/10/00 Port Pirie 23mg/L, 8/1/01 Angaston 22mg/L. Highest SA Water Chlorine Total Levels 2000-12: 7/6/00 Meningie 7.8mg/L.

Chlorine (Free) ADWG Guideline: 5mg/L (Chlorine in chloraminated supplies 4.1mg/L). Chlorine dissociates in water to form free chlorine, which consists of aqueous molecular chlorine, hypochlorous acid and hypochlorite ion.

Chlorine (Total) ADWG Guideline 5mg/L (chloraminated supplies 4.1mg/L): The term total chlorine refers to the sum of free chlorine and combined chlorine present in a sample.