2006/09 + 2014/15: Corinella (Victoria) – Lead, Trihalomethanes, Iron, pH, Turbidity

Corinella – Victoria – Lead

2006/7: Corinella (Victoria) Lead 0.03mg/L (Highest level only)

2008/9 – Corinella (Victoria) Lead 0.026mg/L (Highest Level only)

On 15/02/2007 an elevated lead level was detected in the Corinella and Cowes water sampling locality. Due to the recent previous detections of lead, these exceedances of the ADWG health guidelines were reported to DHS as an incident under section 22 of the Safe Drinking Water Act. The mains in the problem areas were flushed to remove any residual lead. Water quality results on the next sampling event showed that the lead concentration had decreased to below the guideline level. No further actions were taken. Based on health considerations, the concentration of lead in drinking water should not exceed 0.01 mg/L.
http://www.westernportwater.com.au/wp-content/uploads/WebFiles/Services/DHS%20annual%20water%20quality%20report%202006-07.pdf
A sample was taken on 10 February, 2009 at 67 Bayview Road Tenby Point. The lead reading
of 0.026 mg/L was above the ADWG limit of 0.01 mg/L. The cause of the high lead result was difficult to determine. After receiving notification of this lead reading, the main was flushed and no further actions were taken. Because of the time taken to receive this non-compliance result, Weste rnport Water decided it was too late to resample, as this would not have been a representative sample of the original sample date. The above elevated lead reading requires a Section 22 to be forwarded to DHS; however in this instance, it did not occur. Westernport Water and its laboratory services provider, Ecowise Environmental, investigated the processes related to the sample and the timing of exceedence- report generation. Apart from human error associated with the sample, it was difficult to determine the exact cause of non-reporting. Both Westernport Water and Ecowise have reviewed the way the exceedence reports are reported to minimise the chance of reoccurrence happening again.
http://www.westernportwater.com.au/wp-content/uploads/WebFiles/Services/DHS%20annual%20water%20quality%20report%202008-09.pdf

“… Lead can be present in drinking water as a result of dissolution from natural sources, or from household plumbing systems containing lead. These may include lead in pipes, or in solder used to seal joints. The amount of lead dissolved will depend on a number of factors including pH, water hardness and the standing time of the water.

Lead is the most common of the heavy metals and is mined widely throughout the world. It is used in the production of lead acid batteries, solder, alloys, cable sheathing, paint pigments, rust inhibitors, ammunition, glazes and plastic stabilisers. The organo-lead compounds tetramethyl and tetraethyl lead are used extensively as anti-knock and lubricating compounds in gasoline…

Lead can be absorbed by the body through inhalation, ingestion or placental transfer. In adults,
approximately 10% of ingested lead is absorbed but in children this figure can be 4 to 5 times higher. After absorption, the lead is distributed in soft tissue such as the kidney, liver, and bone marrow where it has a biological half-life in adults of less than 40 days, and in skeletal bone where it can persist for 20 to 30 years.

In humans, lead is a cumulative poison that can severely affect the central nervous system. Infants, fetuses and pregnant women are most susceptible. Placental transfer of lead occurs in humans as early as the 12th week of gestation and continues throughout development.

Many epidemiological studies have been carried out on the effects of lead exposure on the intellectual development of children. Although there are some conflicting results, on balance the studies demonstrate that exposure to lead can adversely affect intelligence.

These results are supported by experiments using young primates, where exposure to lead causes significant behavioural and learning difficulties of the same type as those observed in children.

Other adverse effects associated with exposure to high amounts of lead include kidney damage, interference with the production of red blood cells, and interference with the metabolism of calcium needed for bone formation…” ADWG 2011

Corinella (Victoria) – Trihalomethanes

High Levels Only

2007/08: Corinella Trihalomethanes 0.250mg/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/index.cfm

Corinella – Victoria – Iron

2006/7: Corinella (Victoria)  – Iron 730ug/L (Highest level only)

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

Corinella – Victoria – Manganese

2006/7: Corinella (Victoria) – Manganese 0.28mg/L (highest level only)

Manganese: ADWG Guidelines 0.5mg/L. ADWG Aesthetic Guideline 0.1mg/L
Manganese is found in the natural environment. Manganese in drinking water above 0.1mg/L can give water an unpleasant taste and stain plumbling fixtures and laundry.

Corinella (Victoria) – pH

Widespread elevated pH levels were detected in Cowes, Grantville, Corinella, Kilcunda, and Cape Woolamai. They were detected in samples collected on 24/10/2007. The non- compliance with the ADWG health guideline was reported to DHS as an incident under section 22 of the
Safe Drinking Water Act. The pH meter that controls the Caustic Soda dosing was recalibrated and dosing returned to normal. No further actions were taken.

http://www.westernportwater.com.au/wp-content/uploads/WebFiles/Services/DHS%20annual%20water%20quality%20report%202007-08.pdf

Based on the need to reduce corrosion and encrustation in pipes and fittings, the pH of
drinking water should be between 6.5 and 8.5.

New concrete tanks and cement-mortar lined pipes can significantly increase pH and
a value up to 9.2 may be tolerated, provided monitoring indicates no deterioration in
microbiological quality.

pH is a measure of the hydrogen ion concentration of water. It is measured on a logarithmic scale from 0 to 14. A pH of 7 is neutral, greater than 7 is alkaline, and less than 7 is acidic.

One of the major objectives in controlling pH is to minimise corrosion and encrustation in pipes and fittings. Corrosion can be reduced by the formation of a protective layer of calcium carbonate on the inside of the pipe or fitting, and the formation of this layer is affected by pH, temperature, the availability of calcium (hardness) and carbon dioxide. If the water is too alkaline (above pH 8.5), the rapid deposition and build-up of calcium carbonate that can result may eventually block the pipe.

Corinella – Victoria – Turbidity

2014/15: Corinella (Victoria) – Turbidity 5.4 NTU (Maximum detection during year)

Chlorine-resistant pathogen reduction: Where filtration alone is used as the water treatment
process to address identified risks from Cryptosporidium and Giardia, it is essential
that filtration is optimised and consequently the target for the turbidity of water leaving
individual filters should be less than 0.2 NTU, and should not exceed 0.5 NTU at any time
Disinfection: A turbidity of less than 1 NTU is desirable at the time of disinfection with
chlorine unless a higher value can be validated in a specific context.

Aesthetic: Based on aesthetic considerations, the turbidity should not exceed 5 NTU at the
consumer’s tap.