NSW Health documents reveal staff concerns over the “very high risk” of contamination to Bega Valley drinking water.
The GIPA documents obtained by ABC journalist Greg Miskely reveal an internal NSW Health email raised concerns over the “potential health risks” surrounding unfiltered water supplies drawing on surface water, and supplies lacking “an adequate standard of treatment”.
“Based on the Drinking Water Management System risk assessment there is a very high risk from chlorine resistant pathogen contamination due to on-site sewerage system discharges and failures and presence of septic systems in the Bemboka river catchment,” an email from NSW Health’s Water Unit manager Dr Paul Byleveld states.
The emails also focus on the “inability to adequately disinfect the water”, and the possible threat posed by livestock on 12 farms around the Bemboka catchment.
Risk assessments identified unfiltered surface water systems have no treatment barrier against pathogenic Ciyptosporidium, which is resistant to chlorine disinfection, the documents say.
“They also face risks from changes to raw water quality, cyanobacteria blooms and uncontrolled water chemistry,” the documents state.
The email also raises concerns over the fact “recreational activities are permitted on Yellow Pinch Dam that supplies water to over 10,000 people”.
Further emails discuss the introduction of multiple boil water notices by council, supported by the Public Health Unit after consultation with the Water Unit for the Brogo-Bermagui water supply.
A letter from NSW Health’s Dr Kerry Chant, Chief Health Officer and Deputy Secretary of Population and Public Health, to Deputy Director-General of Water at the Department of Primary Industries, states Australian drinking water guidelines recommend more than one barrier be applied to prevent risk events in water supplies.
Water sourced for town water supply in the region is currently disinfected with chlorine, and not filtrated or treated further chemically.
“Most regional water utilities in NSW are constrained in their ability to construct new water treatment infrastructure without support from the NSW Government,” Dr Chant states in the email in December 2015.
Council’s water and sewer manager, Jim Collins, said the introduction of water filtration plants is a priority for all shire water supplies.
He said four boil water notices have been issued by council to residents since 2010.
“In March 2010, a notice was issued for the Bemboka water supply and Bega-Tathra water supply following flooding rains,” he said.
“Three boil water notices have been issued for the Brogo-Bermagui water supply.”
The email from Dr Byleveld states boil water alerts “may present a risk to public health with the potential of burns and scalds”.
“Also repeated boil water alerts can undermine consumer confidence in the drinking water supply,” Dr Bylveld said.
The DPI quotes the cost of achieving health based targets at $1.5billion to $2billion for country towns across the state.
NSW Health’s Dr Kerry Chant said while filtration can provide protection against Ctyptosporidium, cyanobacteria, and changeable raw water quality, it “reduces the turbidity (particles) and dissolved organic material in the water, which if uncontrolled reduces the activity of chlorine and feeds the microbial films lining pipes”.
Mr Collins assured residents Bega Valley water is currently of “high quality”, and there have been “no detections of e-coli or any other pathogenic contaminants in the supplies before or during these boil water notice periods”.
“There have been no water-borne disease outbreaks attributed to BVSC drinking water supplies at any time during their long-term operation over many decades,” Mr Collins said.
“The water quality monitoring evidence shows that drinking water quality in the Bega Valley Shire is of a high standard due to the high quality of local source waters and catchment health, well operated disinfection systems and sound management, maintenance and monitoring of drinking water supplies.
“It is disappointing that members of the public have been left unnecessarily upset and concerned that they may be threatening their own wellbeing by using the water.”