Water consultant Iain Rabbitts was sacked by the Christchurch City Council after saying he believes permanent chlorination in the city is almost inevitable if an independent regulator is brought in.

A water expert brought in to review Christchurch's chlorination programme has been sacked by the city council after raising concerns over public health issues.

Iain Rabbitts​ was employed as an external consultant to carry out health and safety assessments while council engineers roll out temporary treatment ahead of repairs to fix substandard wells across the city.

But his contract was terminated after he publicly gave his view that fixing the faulty well heads is unlikely to prevent the city's water supply having to be chlorinated permanently.

In an article published last week, Rabbitts told Stuff he believes the Government is likely to set up an independent drinking water regulator as part of its response to the 2016 Havelock North outbreak, and that such a body will likely clamp down on unregulated supplies.

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He also suggested that while 103 vulnerable bores are being fixed in Christchurch, about 1850 other unmonitored bores could potentially pollute supplies.

Authorities want the city's famously pure water to be regarded as a "special case", but Rabbitts said he believes there is much more work needed for it to be exempt from any mandatory permanent chlorination.

Following the story's publication, Rabbitts – a water specialist with engineering consultancy Harrison Grierson who was an expert adviser to the Havelock North inquiry – and his employer were told by the council his contract was being terminated.

The council refused to say whether it was ended directly because of his comments, saying the decision had been "mutual" between the authority and his employer because the work was largely completed.

IAIN McGREGOR/STUFF Mayor Lianne Dalziel is adamant water supplies are safe and has vowed to fight "tooth and nail" to keep them chlorine-free in the future.

It is not clear who made the decision, but Christchurch Mayor Lianne Dalziel is known to have been infuriated by his comments.

The council also refused to say whether Rabbitts himself would be considered for future work, though it suggested Harrison Grierson would not be blacklisted from applying for contracts.

In a statement David Adamson, the council's general manager of city services, said: "The council had a contract with Harrison Grierson to provide expert technical advice on the implementation of the temporary chlorination for Christchurch water.

"Harrison Grierson provided a team to undertake this work. It was mutually agreed between the council and Harrison Grierson that as the temporary chlorination was substantially completed it was the right time to finish this contract.

"The council's equipment supply and physical works contractors along with council staff had enough expertise to finish the works in a professional and cost-effective manner.

"Harrison Grierson have supplied services to the council for a number of years. There is no reason why in the future they will not continue to do this.

"The council assumes Harrison Grierson will provide as part of any future proposal a list of suitably qualified personnel to undertake the necessary works for which they are bidding."

JOHN KIRK-ANDERSON/STUFF Repairs are being carried out across Christchurch to ensure well heads are safe from potential contamination.

Rabbitts declined to comment when contacted by Stuff.

In the wide-ranging interview published last week, Rabbitts said he believed permanent chlorination was the only feasible option to make certain Christchurch's water supply was safe for public consumption.

He also said that despite the council's best intentions, there was no chance work to fix the damaged well heads will be completed within 12 months, meaning the current chlorination will continue beyond a year.

Dalziel said she would fight "tooth and nail" for the water supply to be saved from any mandatory permanent chlorination, saying she had "absolute confidence" in the supply.

Adamson said water from aquifers beneath the city was extensively monitored and secure.