Pesticide Hot Spot: For Mackay also see Nebo Road WTP
2017/18 – Mackay (Queensland) – E.coli
July 24 2017: E. coli was detected in a sample collected from McEwens Beach as part of the routine drinking water monitoring program. It is believed the E. coli detection was due to frogs
found within the sample tap. In response to this incident a plug was installed at the sample tap to ensure no frogs could make their way back in.
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
2017/18 – Mackay (Queensland) – Lead
2017/18: 0.02381mg/L (max).
2020/21: Nebo Road Treated 0.0338mg/L (max), 0.0011(mean)
October 4 2017: Lead was detected at a concentration above the ADWG health guideline in a sample collected from Seaforth as part of the routine drinking water monitoring program.
Sample tap deterioration was deemed to be the cause of the high lead result. The sample tap
has since been replaced and a sample tap cover installed as part of MRC’s drinking water sample point refurbishment program.
Feb 26 2018: Lead was detected at a concentration above the ADWG health guideline in a sample collected from McEwens Beach as part of the routine drinking water monitoring program. Sample tap deterioration was deemed to be the cause of the high lead result. The sample tap has since been replaced.
July 26 2021: Lead was detected during routine sampling a Walkerston 1 – Skate Park, above the ADWG heath guideline value of 0.01mg/L. Elevated turbidity and iron results were also identified. A sample taken on the same day from a nearby drinking monitoring point returned a compliant result, indicating the breach was localised.
Additional sampling at the Skate Park on 3 August 2021, the Walkerston Reservoir and nearby drinking water sample points returned results that were compliant with the ADWG guidelines. An inspection of the Walkerston 1 – Skate Park sample tap identified that there was degradation of the tap. The sample box also had obvious signs of maintenance work, with the latch having been recently repaired. It is likely that the cause of the high lead, turbidity and iron levels are related to the degradation of the sample tap and the repairs to the sample box. No immediate corrective actions were undertaken as water quality results from nearby sample points and follow up sampling from 3 August 2021 did not indicate any ongoing issues.
Guideline Level 0.01mg/L
“… 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…ADWG 2011
Mackay (Qld) – Turbidity
2020/21: Mackay Reticulation (Qld) Turbidity 6.4NTU (max), 0.3NTU (mean)
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.
Mackay (Qld) – Iron
2020/21: Mackay Reticulation (Qld) Iron 0.43745 (max), 0.0199NTU (mean)
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
Mackay tap water, once rated country’s best, now brown and dirty
Jan 12 2021
https://www.abc.net.au/news/2021-01-12/mackay-tap-water-brown-and-dirty/13047630
Less than two years ago, Mackay was named as having “Australia’s best-tasting tap water”, but that honour has gone down the drain in recent weeks.
Bucasia resident Jade Hayward used to take the high quality of the city’s water for granted. Afterall, Mackay’s tap water was named Australia’s best by the Water Industry Operators Association of Australia (WIOA) in 2019.
But last week, she became alarmed when she was running a bath for her children and noticed how discoloured the water was.
“I went in to check on the bath, the water was half full and it was … a rusty dirt brown,” she said.
“You could still see the bottom of the bath, but it was still dirty to look at.
“The council came to our home and said it wasn’t their issue, it was our issue.”
Ms Hayward assumed the issue was caused by rusty pipes, but after her partner checked them throughout their property, they realised the issue was external as all their pipes were plastic.
“The fact they said it was our issue and they didn’t test the water made me angry,” she said.
Multiple reports of dirty water
Ms Hayward took to social media, posting to local community groups about the issue.
Dozens of people on social media across suburbs including South Mackay, the CBD and Beaconsfield also reported similar problems with water discolouration.
Mackay Regional Council has blamed the discolouration on heavy rainfall across the region over the past week.
“The extended rain period has made the river water dirtier and more difficult to treat,” a council spokesperson said.
“Council has had to supplement the supply with bore water from the Nebo Road Water Treatment Plant.
“The bore water has a higher iron concentration than the river water and customers may be noticing a slight brown or cloudy discolouration in their water supply.”
Water still safe to drink, says council
The spokesperson said despite the discolouration, the water continued to meet the Australian Drinking Water Guidelines and was safe to drink.
“Council conducts regular water quality testing and any results that don’t meet the guideline values are reported to Queensland Health,” the spokesperson said.
Rossarden, in north-east Tasmania, was awarded the title of “best drinking water in Australia” by WIOA in 2020.