Human faecal matter leaking from septic tanks has regularly contaminated the Urenui River and mudflats. FIle photo. Photo: Supplied
The cost of a proposed sewerage scheme for two popular Taranaki beach settlements has blown out to $41 million - $180,000 for each household - according to a new report.
New Plymouth District Council's strategic projects committee is considering the Urenui and Onaero Wastewater - Deep Dive report on Wednesday morning.
Human faecal matter leaking from septic tanks in the area contaminating the Urenui River and mudflats was a long-standing issue, the report said, noting the "property size and soil [type was] not suitable for septic tanks in large parts of Urenui and Onaero townships".
It said the current Urenui septic tank drain field at the Urenui Domain was on land significant to Ngāti Mutunga, while the leach fields at Onaero were close to an eroding cliff.
Flow rates at both septic tank drain fields were in breach of current resource consents and subject to abatement notices.
The report said when a scheme to treat wastewater in the area was first mooted in 2004 it was estimated to cost $4 million. Its latest estimate is $41 million - $180,000 for each of the 228 households currently in the area.
In the 2006 Long-Term Plan (LTP) it was proposed to start construction in 2008/2009, but in the subsequent LTP councillors kicked it down the road for three years and revised the estimated cost to $14 million.
It was removed completely from the 2012 LTP due to cost increases and not reintroduced until the 2021-2031 LTP after the community identified solving the human waste problem as a "high priority".
At this stage consultation began about a local treatment plant and discharge of treated waste to land. The cost estimate based on minimal planning work was now $29 million.
Progression of the sewerage scheme was proposed in the 2024-2034 LTP, which calls for options to be finalised and consenting work to begin and for additional funding to be found for the new estimated cost of $41 million.
But even that came with a warning.
"The current estimate is still considered to be a preliminary [Class 5] estimate. Further assessment of options is required prior to preparing applications for resource consents and site designations which are significant unknowns, so budget is subject to future change," the deep-dive report said.
The council has already spent at least $8 million on the project.
In 2020, it bought a 41-hectare $3.3 million Waiau Road property for the proposed plant, but that came up against community resistance.
The deep-dive report reveals council has now bought an 84 hectare Main North Road property in Onaero for $5.5 million and is hoping to sell the Waiau Road property for its purchase price.
Councillors were not expected to make any decisions on the proposed project today.