"We have a responsibility to deliver infrastructure that's efficient, effective and appropriate - I do not have confidence we can meet that."
She said the report would make recommendations on the appropriateness of the Waipukurau wastewater system and its ability to meet resource consent requirements.
For both systems, the regional council requirements would be considered, as well as their capacity to deal with residential and trade demands as well as the growing population.
The report would outline any potential capital investment required to address the issues and the results would be used to inform the Long Term Plan, working with potential external funders and capital works.
"I want to be extremely clear around our expectations - we have been patient but there comes a time we have to put a stake in the ground very firmly," Ms Walker said.
Councillor Shelley Burne-Field said this was one of a number of legacy issues the council had been unravelling over the last year.
"This is one of those items. In the past this issue has been kick the can down the road, it's been put in the too hard basket."
She said the situation was hard on staff, with options such as putting the wastewater on to land purchased by the Hawke's Bay Regional Council rejected due to political reasons.
Deputy mayor Ian Sharp, who was on council when the decision was made to go with floating wetland wastewater treatment plants at both sites, said he hoped the report focused on solutions going forward and not on the past.
"Blaming everyone else seems to be a favourite topic around this table.
"It's hard to convince people we really are concerned because they do not see anything happening - as long as this does not become a witch hunt to blame people."
Councillor Gerard Minehan lived near the Waipukurau treatment plant and said the odour had worsened again in recent weeks and his frequent communications with residents had shown they were "at the end of their tether and so am I quite frankly".
Chief executive Monique Davidson said the Waipukurau plant had been under review over the last year, while a separate review of the Waipawa plant had been prompted by an Environment Court enforcement order, following the Hawke's Bay Regional Council's prosecution of the CHB council over a consent breach.
The total cost of that review and any subsequent actions was capped at $100,000, which would be sourced from the existing wastewater renewal budget.
Mrs Davidson said the report due in November would cost between $10,000 and $20,000 (funded from the operational budgets), authored by two independent experts who were working collaboratively.
Once completed it would be presented to the finance and planning committee, which comprised all councillors.