2004-14 – Bemboka (New South Wales) – E.coli, Iron, Copper

2010 – 2014 Bemboka (New South Wales) – E.coli
From a total of 265 samples, 2 E.coli detections occurred from 1 Jan 2004 to 31 Mar 2014.
Detection dates: 14 Sept 2010 and 30 Jan 2013 at sample sites 512 and 510 respectively. In
both instances 1 cfu/100 mL and 2 cfu/100mL of total coliforms was detected. Re‐sampling was
undertaken with no E. coli detected.

Thermotolerant coliforms are a sub-group of coliforms that are able to grow at 44.5 ± 0.2°C. E. coli is the most common thermotolerant coliform present in faeces and is regarded as the most specific indicator of recent faecal contamination because generally it is not capable of growth in the environment. In contrast, some other thermotolerant coliforms (including strains of Klebsiella, Citrobacter and Enterobacter) are able to grow in the environment and their presence is not necessarily related to faecal contamination. While tests for thermotolerant coliforms can be simpler than for E. coli, E. coli is considered a superior indicator for detecting faecal contamination…” ADWG

2004-14 Bemboka (New South Wales) – Iron

From a total of 21 samples, there were 13 exceedances from 1 Jan 2004 to 31 Mar 2014. The
ADWG value for iron is based on aesthetic considerations is 0.3 mg/L.

Based on aesthetic considerations (precipitation of iron from solution and taste),
the concentration of iron in drinking water should not exceed 0.3 mg/L.
No health-based guideline value has been set for iron.

Iron has a taste threshold of about 0.3 mg/L in water, and becomes objectionable above 3 mg/L. High iron concentrations give water an undesirable rust-brown appearance and can cause staining of laundry and plumbing fittings, fouling of ion-exchange softeners, and blockages in irrigation systems. Growths of iron bacteria, which concentrate iron, may cause taste and odour problems and lead to pipe restrictions, blockages and corrosion. ADWG 2011

2010 – Bemboka (New South Wales) – Copper

From a total of 21 samples, one exceedance occured from 1 Jan 2004 to 31 Mar 2014. The high
copper exceedance was 2.05 mg/L at sample site 513 on 15 Nov 2010.

Based on health considerations, the concentration of copper in drinking water should not
exceed 2 mg/L.
Based on aesthetic considerations, the concentration of copper in drinking water should
not exceed 1 mg/L.

Copper is widely distributed in rocks and soils as carbonate and sulfide minerals.

Copper is relatively resistant to corrosion and is used in domestic water supply pipes and fittings. It is also used in the electroplating and chemical industries, and in many household goods. Copper sulfate is used extensively to control the growth of algae in water storages.

Copper is present in uncontaminated surface waters at very low concentrations, usually less than 0.01 mg/L. The concentration can rise substantially when water with a low pH and hardness remains in stagnant contact with copper pipes and fittings. Under these conditions, the concentration of copper can reach 5 mg/L or higher. In one extreme case overseas, a concentration of 22 mg/L was reported.