But the report failed to find the source of false positive tests of E. coli and coliform that sparked a two-day, city-wide boil-water advisory.
Geoff Patton, the city's director of water and waste, says the report by an external consultant has found that the problem likely stemmed from contamination in the way water samples were collected or in the lab that tested the water.
The Manitoba government ordered the external probe and is currently reviewing the 700-page report.
It was routine testing that turned up what appeared to be very low levels of E. coli and coliform in six of 39 locations in the city's water supply.
Patton says there is no way to be more specific about where the contamination came from — lab or sampling — and the city is working on improvements to its sampling and testing methods.
"All we were able to determine ... is that's basically where the issue occured and we're unable to point conclusively to either process," he told reporters Friday.
The review also couldn't determine whether the problems stemmed from equipment or human error, Patton added.
"There's a number of opportunities for a potential issue to occur. There's a simple touching (of) your eye, touching the edge of a bottle. There are a number of processes."