Raglan sewage discharge costs $56,250

The Waikato District Council has been fined $56,250 for discharging five million litres of partially-treated sewage into Raglan Harbour.

It's a fair penalty for a bad mistake, the council's chief executive reckons.

The discharge, in June last year, was due to an overflowing treatment pond at the Raglan wastewater treatment plant into an estuarine arm of the harbour.

The overflow happened over three days and resulted in contaminant flowing past the local boat ramp, camp ground and over shellfish beds, provoking outrage, including a call from Raglan Community Board member Bob MacLeod for "heads to roll".

In imposing the fine, Hamilton District Court Judge David Kirkpatrick said the errors committed by district council staff were "of a systemic nature, revealing poor training, supervision and ultimate[ly] management".

The judge went on to say "once the overflow commenced, the failure of the defendant's staff to alert senior council managers, the council itself, the regional council and the community also seriously aggravated the offending.

"Such failures meant that the people who were or could be directly affected were denied any information on which they might have acted to avoid the potential consequential effects on their health that such a discharge could cause."

No evidence had been submitted in the case that anyone had suffered any ill effects as a result of the discharge and that was "fortuitous", the judge said.

Kirkpatrick also acknowledged the district council "as a public body, does treat its environmental responsibilities as important".

The prosecution was initiated under the Resource Management Act by the regional council.

Waikato District Council chief executive Gavin Ion said lessons had been taken on board by the council.

"This process has been challenging for everyone involved. However we need to be accountable for our actions and we accept this fine as a fair penalty for a regrettable incident.

"Immediately after an internal investigation into the incident, a number of actions were put in place to ensure this situation doesn't occur again. This includes a major upgrade of our wastewater treatment plant monitoring systems district-wide.

"We're also taking every opportunity to strengthen our relationship with the affected community to develop open and transparent communication channels at all times."