Plumbers spoken to yesterday said, if anything, the council's building inspectors were too rigorous when examining their handiwork on new homes.
"They are doing too good a job," growled one Aitken Plumbers Ltd employee, who would not give his name.
"They are not very popular with us. We have just got to do everything exactly to the letter of the plumbing law. It can cost people a lot of money."
Others spoken to argued the media attention on the problem of cross-connected pipes was "blowing it all out of proportion" and feared the only result would be even more vigilance by council inspectors.
Drainage Solutions Ltd drainlayer Michael Hammer said he had come across "three or four" examples of cross-connected pipes in the past eight years, although he stressed none was the result of his work.
"[It's] quite shocking really - it all comes down to reading plans," he said.
However, blaming council inspectors for missing a fault like that at Orchard Grove was "quite unreasonable", he said.
"They [city inspectors] don't know what connection is what. It's up to the drainlayers to read the plans properly," he said.
The error - which went undetected for 18 months - saw a sewerage pipe mistakenly connected to a stormwater drain, emptying human waste from a new home into a creek running through the upmarket sub-division.
The mistake was repeated six months ago, when plumbers working on a second home in the subdivision copied the work from the first house.
Avon Plumbers owner Wayne MacDonald, of Dunedin, said such connection faults could easily be missed, particularly when working on homes in new subdivisions.
"You have got pipes of the same colour and same diameter, so it's easy enough to make a mistake," he said.
A. G. Foley Plumbers Ltd director Chris Sutherland, of Dunedin, agreed.
His company had worked to rectify similar problems before in Dunedin, and was responsible for one fault during his 20 years with the company.
"It's not an uncommon thing, but I wouldn't hold the council responsible. It rests on the plumber.
"The inspectors are not there to go check every little nth degree," Mr Sutherland said.
The Otago Regional Council is awaiting results of water tests conducted on Tuesday, expected within days, and a staff report into the contamination, expected in weeks, before deciding what action - if any - to take.
Regional council director of resource management Selva Selvarajah, who on Tuesday criticised the council's inspections regime, said a prosecution could be launched once results were in.
City council development services manager Kevin Thompson has defended the inspections process, blaming the plumbers involved and saying it was "not unreasonable" for the mistake to be missed by council staff.
