Questions raised over drinking water

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But councils say testing process is the problem

CAL ROBERTS
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Wairarapa drinking water has received a chequered report from the Ministry of Health, with water standards not being met in several of the region’s towns.

But those charged with keeping our water safe say the testing process is partly to blame, and the fail marks don’t mean we’re not getting good, clean water in our taps.

An annual report on drinking water quality published last week for the period July 2016 to June 2017, shows one in five people in New Zealand are drinking water from a source which does not meet safe drinking water standards.

Drinking water was measured against three standards – bacteria, protozoa and chemical.

The report shows that Featherston failed all three standards, Greytown and Martinborough failed the bacteria and protozoa standards, while Carterton failed the protozoa standard.

Masterton passed all three standards.

South Wairarapa District Council chief executive Paul Crimp said the results were disappointing, and not representative of water quality in the area.

Rather, the council had not completed the number of tests required, so failed some of the standards.

He said in Greytown, 32 samples of a required 52 were completed.

“In Martinborough we took 107 which is over the required 104, but as we missed taking one weekend sample it is reported as a ‘total fail’.

“Both these sampling indiscretions result in a fail. As I say, the fail is not in actually detecting bacteria and protozoa, it is missing sampling.”

Crimp said he didn’t want to underestimate the importance of drinking water safety.

“The results are disappointing in that they relate to the sampling regime rather than the presence of any contaminants.”

He said Featherston’s water had failed because of a lack of regular testing, having sampled 49 times rather than 52.

“In no cases did any samples show positive readings for bacteria and protozoa.

“Our theory is correct, our practice is not.”

Chemical standards were tested against 12 samples over the year. Featherston completed two.

Crimp said the council would be working with its contractor to improve the sampling regime.

In Carterton, one of the challenges was recording information in a format that was favourable for assessors.

Council chief executive Jane Davis said the non-compliance reported by the ministry reflected more the processes of aquifer designation requiring a greater level of monitoring rather than any greater risk to the Carterton community.

Since the end of the report’s sample date, CDC officer Selwyn Osborne said Carterton “has been doing more than it needs to”.

“We monitor daily and sample weekly. This is how greatly we value the safety of our drinking water.”

For Masterton, its council-owned supply was given three ticks, meeting all standards required to maintain a healthy pool of drinking water.

The latest results are inline with the previous report covering 2015-2016.

Masterton District Council’s acting chief executive David Hopman, said it was good to have its water treatment methods and procedures formally recognised again as meeting government expectations.

“We carry out stringent testing and treatment, including coagulation, filtration and treatment to ensure Masterton’s water supply is safe to drink.”

Two zones not owned by the council, Opaki and Wainuioru rural water, did not meet standards.

The council’s infrastructural services committee has an obligation to encourage individuals to treat water before consumption.

Lobby group Water New Zealand’s chief executive, John Pfahlert, said the results were not good enough.

“I think we simply can and should do better.”

Pfahlert said sometimes a failure to comply with the standards was “technical”.

“They might not have done the right amount of samples or they might have done them at the wrong time.”

The report showed more than 81 per cent of the country received drinking water which met all requirements of the standards.

He said discussion needed to go beyond beating up on small communities such as Wairarapa for failing standards.

How testing is done

The testing was carried out by the Institute of Environmental Science and Research under contract with the Ministry of Health.

Passing bacteria standards was determined primarily by monitoring E.coli levels.

Protozoa standards are based on the likelihood that the water’s treatment process will protect the community if pathogens like cryptosporidium are present.

Chemical standards are assessed by monitoring chemicals, such as fluoride, in water supplies to ensure they were within safe levels where present.