Dechlorination of city’s water ‘just weeks away’
One in five Christchurch residents could be drinking largely chlorine-free water in just a matter of weeks.
The Christchurch City Council announced on Tuesday that seven pump stations out of the city’s 56 could be dechlorinated as soon as early August.
The changes would affect
27,000 of Christchurch’s 145,000 households – affecting about 19 per cent of the population.
It looked likely to affect parts of Belfast, Redwood, Bishopdale and Burnside in the city’s northwest; parts of Mairehau and Burwood in the city’s north-east, and Woolston in the south-east.
Christchurch drinking water to be chlorinated for a year as councillors approve plan to keep it safe.
Water supply improvements programme manager Helen Beaumont said living in those areas carried no chlorine-free guarantee as the city’s water supply system was interlinked.
‘‘The number of households supplied from a particular pump station does vary depending on the demand for water and which pumps are in operation.
‘‘That also means that an individual household may receive water from a different pump station at different times.’’
The changes will affect 17,500 households in the north-west,
6000 in the north-east and 3700 in Woolston.
The council has begun minor remedial works on 23 above ground well heads at the seven pump stations so they can be ticked off for dechlorination.
In a press release, the council said the remedial work and subsequent inspections were expected to be completed by the end of July. Any below well ground heads in those areas will be isolated, allowing chlorination to be stopped.
The council originally ruled out ultra violet (UV) light disinfection as too expensive, but said in the release that it was ‘‘feasible and we are assessing the costs and benefits of using UV at a number of pump stations’’.
The council has completed preliminary design work for UV disinfection at the main central city supply zone in Beckenham.
The council’s infrastructure, transport and environment committee will consider a recommendation that the council seek tenders for the work at its next meeting.
In January this year, the council voted for temporary chlorination of the city’s water supply while well heads were repaired in anticipation of expected changes to New Zealand’s water standards, following the 2016 Havelock North campylobacter outbreak which made 4000 sick.
The subsequent rollout of chlorination across the city resulted in public complaints about the water’s taste and smell, and various claims as to its effect on health.
Three pump stations in New Brighton and Prestons were the only ones to escape the rollout as they were deemed above-ground and secure.