A proposal to dispose of wastewater to land in the Tairua Forest as part of the planned multi-million dollar upgrade and expansion of the Whangamata Wastewater Treatment Plant is appropriate and necessary, an Environment Waikato Hearing Committee has found.
In its decision released on Monday, the four-member regional council committee granted the Thames-Coromandel District Council resource consent to discharge treated wastewater to land and contaminants to air (mainly odours) in association with the operation of the proposed upgraded treatment plant.
At the hearing in Whangamata last month, the committee heard evidence from the district council regarding the proposed upgrade of the treatment plant and the potential environmental effects of the proposal.
It also considered submissions from a number of people opposing the proposal or requesting special conditions.
“The committee was impressed with the comprehensive case made for upgrading the treatment plant and disposal system,” said hearing committee chairman Rex Hawkins.
“Whangamata needs a system that can cope with the holiday peak demand, provide capacity for an increasing population and reduce the impact on the environment of the treated effluent discharge.
“The committee is satisfied that the resource consent conditions imposed, the mitigations proposed and the implementation of a comprehensive monitoring programme will ensure the plant is unlikely to have any adverse effects on people or the environment.”
The district council proposes to change the treatment and disposal process which will greatly reduce nitrogen loading to groundwater and the risk of faecal contaminants polluting nearby streams.
The committee gave special consideration to concerns about the location of the plant but found that the new system will be a clean, sealed system with no discharge or leakages to the environment.
Requests that the wastewater be treated to drinking water standards prior to discharge to land in the Tairua Forest were considered. The committee found however that treating the water to such a standard would impose significant and unnecessary cost on ratepayers of Whangamata.
In light of concerns about the possible effects of seepage on the Moanaanuanu Estuary from the plant’s unsealed holding pond, the committee called for a full investigation into the geotechnical properties and potential stability of the lagoon. The seepage of wastewater from the lagoon is still the subject of a resource consent application on hold with Environment Waikato.
The committee also included a review clause to allow the potential effects of hormones such as oestrogen or other possible wastewater constituents entering water and affecting fish or other kaimoana to be investigated should issues arise in the future.
The potential effects on human health were also considered. The committee accepted that increasing the buffer distance for properties bordering the spray zone from 70 to 100 metres should alleviate concerns about spray drift or overland flow.
The consents expire in 30 years at the end of November 2036.
The hearing committee comprised three representatives from regional council Environment Waikato Councillors Rex Hawkins, Steve Osborne, Jim Howland and Commissioner Robert Koroheke.