The Horowhenua District Council has hit back at Green Party allegations that the Levin wastewater treatment plant is leaking into Lake Horowhenua, claiming that Green co-leader Russel Norman is “simply political point scoring.”

“It is extremely disappointing that the Greens have chosen to offer wide-ranging criticism, much of it based on speculation rather than fact,” HDC chief executive David Ward said.

Mr Ward believes heavy rainfall has pushed the average rainfall levels in July and August past record levels.

“While currently the rainfall has ceased, unfortunately the effect will continue to affect groundwater levels for some time,” he said.

Mr Norman had argued that mayor Brendan Duffy should resign over what he claims is “one of New Zealand's worst sewage disasters in years.”

Mr Ward rejected the claims and said: “It is important that we acknowledge that the buffer storage ponds hold treated effluent. We are mindful that the impact of groundwater levels will continue to be with us for some time, Mr Ward said.

“The situation that the council is currently facing is outside its control – we are dealing with highest ever recorded groundwater levels – a result of an act of nature, not an act of Council.”