Drinking water repeatedly contaminated with pathogens in rural NSW towns
9 October 2017: https://www.abc.net.au/news/2017-09-06/drinking-water-contaminated-with-pathogens-in-nsw-towns/8875464
NSW Health documents obtained by the ABC reveal areas where deadly pathogens are regularly detected at dangerous levels in unfiltered drinking water pumped from rivers, lakes and dams.
The water safety reports, obtained after a lengthy freedom-of-information battle, also show more than 100,000 NSW residents were issued protective boil-water alerts in the last five years.
Grafton, Kempsey, Scone, Jindabyne and Bega are cited as the five worst-performing areas, with repeated “contamination incidents” triggering “potential health risks”.
Around Grafton, a population of 40,000 are at risk from cryptosporidium, a parasite that causes gastrointestinal illness.
Residents have faced 10 boil-water alerts since 2006, issued “in response to the inability of the water supply system to manage risks”.
The documents say faecal contamination from cattle, and even swimmers along the lower Clarence River catchment, is the parasite’s source.
Similar problems plague the Bemboka River catchment, near Bega, with four boil-water alerts issued by Bega Valley Council in 10 years.
Deadly bugs originate in “onsite sewerage system discharges”, “failures and presence of septic systems” and from dairy farms upstream.
The documents say “chlorine-resistant pathogens” — not killed by chemical treatments — are a threat to more than 40,000 people.
Around Kempsey, the risk identified is cyanobacteria — a toxic blue-green algae that can shut supply for 15,000 residents.
Grazing dairy cattle and raw sewage discharges near the Steuart McIntyre Dam trigger algae outbreaks here.
Alarmingly, the documents say “all pathogen groups” including e. coli are present in Kempsey water, and that a further “vulnerability assessment” should be undertaken.
In the Upper Hunter, more than 6,000 residents in Scone, Murrurundi and Aberdeen are rated at “very high risk” from dangerous pathogens flowing from an abattoir and septic tanks in the catchment.
The alpine towns of Jindabyne and Barry Way also face a “moderate risk from the presence of cryptosporidium” as well as toxic “blue-green algae” in their catchment.
Livestock faeces, and sewage, including from the Perisher ski resort are blamed.
The documents also identify other communities with one-off water concerns.
Last year boil-water alerts were issued in Dubbo, as well as villages including Toomelah, Gravesend, and Jubullum.
In the Upper Hunter, more than 6,000 residents in Scone, Murrurundi and Aberdeen are rated at “very high risk” from dangerous pathogens flowing from an abattoir and septic tanks in the catchment.
The alpine towns of Jindabyne and Barry Way also face a “moderate risk from the presence of cryptosporidium” as well as toxic “blue-green algae” in their catchment.
Livestock faeces, and sewage, including from the Perisher ski resort are blamed.
The documents also identify other communities with one-off water concerns.
Last year boil-water alerts were issued in Dubbo, as well as villages including Toomelah, Gravesend, and Jubullum.
“In recent years, Cryptosporidium has come to be regarded as one of the most important waterborne human pathogens in developed countries. Over 30 outbreaks associated with drinking water have beenreported in North America and Britain, with the largest infecting an estimated 403,000 people (Mackenzieet al. 1994). Recent research has led to improved methods for testing water for the presence of humaninfectious species, although such tests remain technically demanding and relatively expensive.
Cryptosporidium is an obligate parasite with a complex life cycle that involves intracellular development in the gut wall, with sexual and asexual reproduction. Thick-walled oocysts, shed in faeces are responsible for transmission. Concentrations of oocysts as high as 14,000 per litre in raw sewage and 5,800 per litre in surface water have been reported (Madore et al. 1987). Oocysts are robust and can survive for weeks to months in fresh water under cold conditions (King and Monis 2007).
There are a number of species of Cryptosporidium, with C. hominis and C. parvum identified as the main causes of disease (cryptosporidiosis) in humans. C. hominis appears to be confined to human hosts, while the C. parvum strains that infect humans also occur in cattle and sheep. C. parvum infection sare particularly common in young animals, and it has been reported that infected calves can excrete up to 10 billion oocysts in one day. Waterborne outbreaks of cryptosporidiosis have been attributed to inadequate or faulty treatment and contamination by human or livestock (particularly cattle) waste.
C. hominis and C. parvum can be distinguished from one another and from other Cryptosporidium species by a number of genotyping methods. Infectivity tests using cell culture techniques have also been developed. Consumption of contaminated drinking water is only one of several mechanisms by which transmission (faecal-oral) can occur. Recreational waters, including swimming pools, are an important source of cryptosporidiosis and direct contact with a human carrier is also a common route of transmission.Transmission of Cryptosporidium can also occur by contact with infected farm animals, and occasionally through contaminated food.” ADWG 2011
Iron the cause of Bega, Tathra brown water woes
https://www.begadistrictnews.com.au/story/5631365/iron-the-cause-of-bega-tathra-brown-water-woes/
Sep 26 2018
Analysis of discoloured tap water samples taken following reports from Bega and Tathra residents and business owners in recent weeks has shown the predominant cause of the discolouration to be iron, council says.
Naturally occurring iron in the groundwater from the Bega Borefield supply source and corrosion of water supply network infrastructure are the known causes of this issue.
Periodically these iron deposits become disturbed and subsequently flow from taps at home, giving the water a rust-brown appearance and sometimes also staining laundry.
However, the council said, iron in drinking water is an aesthetic issue, not a health one.
BVSC Water and Sewerage Services manager Jim Collins said without the existence of a water treatment plant to remove the iron from the water, small solids flow through and deposit in the system, particularly in those areas where water flow is low.
“The water is disinfected, safe to drink and of a high quality in terms of most indicators, however we fully understand that when the water is discoloured it can be unpleasant and annoying for people,” Mr Collins said.
“Impacts on laundry and poor experiences for visitors to holiday accommodation are particularly regrettable and we are continually looking at solutions.
“In the immediate term, we will continue with our water mains flushing program, however the effectiveness of this method is limited by the water pressures and flow available and other cleaning techniques are also needed and used periodically, such as air scouring and ice-pigging.
“We (Council) are also purchasing an in-pipe camera and tapping gear to allow staff to undertake a more detailed inspection of the various pipes and fittings in the area and more effectively prioritise asset renewals.
“The water mains in Tathra, including Andy Poole Drive and Bega Street, will be among the first to be examined in this way.”
Mr Collins said the construction of four water treatment plants remained a primary focus and a reserve balance of $10million has been set aside to help achieve that goal.
“But we won’t be able to deliver these in a timely manner solely through current income sources without excessive borrowings and/or a major increase in residential water and sewer bills.
“As such we have submitted an expression of interest application to the NSW Government Safe and Secure Water Program for the scoping phase of a water treatment plant at South Bega. This will include water treatment options planning and site investigations,” Mr Collins said.
Council keeps a record of all discoloured water complaints so that any particularly troublesome locations can be investigated. People experiencing issues are encouraged to lodge a report on 6499 2222.
readings) from 1 Jan 2004 to 31 Mar 2014. The two exceedances of 1.97 and 1.53 mg/L
occurred on 27 Jan 2009 and 16 Apr 2010, respectively.
“Fluoride occurs naturally in seawater (1.4 mg/L), soil (up to 300 parts per million) and air (from volcanic gases and industrial pollution). Naturally occurring fluoride concentrations in drinking water depend on the type of soil and rock through which the water drains. Generally, concentrations in surface water are relatively low (<0.1–0.5 mg/L), while water from deeper wells may have quite high concentrations (1–10 mg/L) if the rock formations are fluoride-rich.” 2011 ADWG.
Bega (New South Wales) – Turbidity
From a total of 120 samples, 1 exceedance of turbidity has occurred from 1 Jan 2004 to 31 Mar
2014. The 31.3 NTU exceedance was recorded on 4 July 2011 at sample site 121 in Bega. This
exceedance was likely due to iron, recorded at a concentration of 2.5 mg/L in the same sample.
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.