"They are taking this very seriously," he said.
Mr Waugh said Midwest manager Paul Mullinger felt it was not an insurmountable problem.
"They're keen to talk with council and they know the cost is going to be on them. Their preference is on-site treatment, and they are well aware of the expectation on them and their obligations."
Mr Waugh said he expected "a clear plan as to what we or they are going to do over the next few months".
Mr Mullinger said Midwest were looking at a range of options for either pre-treatment or total treatment of the leachate. "To do nothing is not an option," he said. "We're looking at immediate things we can do and long-term options."
Councillor Nigel Belsham asked if Midwest would accept any sludge cleaned out of the plant in the future, and Mr Waugh said it was something Midwest were expecting - "I don't expect any price gouging either."
Committee chairman Dean McManaway said he was pleased discussions had been advanced. "It's good to see we've still got the hammer down on this."
Meanwhile the latest council report shows the wastewater plant is still non-compliant.