Excess levels of manganese are to blame for recurring brown water problems in Winnipeg -- and a chemical used to treat the water supply could be exacerbating the problem, a city-commissioned report has found.

An independent report released Thursday blamed the naturally-occurring metal, which is found in groundwater, while city officials stressed there are no health issues.

“I’m not an expert,” said Mayor Sam Katz. “I can tell you, I sat in a room with an expert – Dr. Richards, and we were told our water is safe, period.”

"Yes, the water is safe," confirms the report, which notes the manganese levels have risen slightly over the years in Shoal Lake, Winnipeg’s water source.

However, the primary source of the increase in manganese is ferric chloride, used in one of the key treatment processes (coagulation) at the drinking water treatment plant, the report states.

Each red dot represents a report to the city about discoloured water. (City of Winnipeg) The materials used to manufacture ferric chloride contain manganese.

The report also said the problem could be worse because the city switched types of ferric chloride last year.

"... a change in chemical supplier in 2013 resulted in a product with higher concentration of manganese, although the chemical product does meet industry standards for water treatment use,” the report said.

Despite the increased presence of the manganese, the levels have remained well below World Health Organization and Health Canada guidelines, said Diane Sacher, the city's director of water and waste.

The consultants who wrote the report provided a number of recommendations for the city, and "we are already putting these recommendations in to action," said Sacher.

The solution

“To get the buildup of manganese out of reservoirs and water mains, we are ramping up cleaning schedules,” said Sacher

The city’s 2,500 kilometres of water mains will be flushed and cleaned within two years, a process that would normally take six years, said Sacher.

Mayor Sam Katz, Diane Sacher, director of water and waste department, and Coun. Justin Swandel, public works chair, address the media on Thursday about the brown water report. (Alana Cole/CBC) ​“Winnipeggers should expect to see some difference this summer since we’re starting this work immediately,” she said.

The city is also looking to replace the type of ferric chloride — used in drinking water treatment plants across North America — with a new water treatment product that contains lower levels of manganese.

The city will also change its water treatment process to better filter manganese.

“Until now, we haven’t been able to pinpoint the cause of increased occurrences of discoloured water,” said Mayor Sam Katz. “This report gives us the answers we need. Now we can get on with implementing solutions.”

The city will also hire an independent consultant to monitor the implementation of the recommendations at a cost of $500,000.

Brown water compensation

Thousands of Winnipeggers have complained about discoloured tap water — in some cases, as dark as coffee — showing up sporadically since last summer.

A number of Winnipeggers have had their clothes and other property ruined as a result of brown water, and the city has provided some compensation to them.

On Thursday, officials released a breakdown of claims and payouts since January 2013.

A total of 21 people successfully filed compensation claims related to brown water, totalling a city payout of about $1,318.14.

The following is a breakdown of how the city has handled the requests for reimbursements: