A $19 million water treatment plant is being built in Brooklyn Center, a project that will improve the safety and aesthetics of the city's water supply.

The plant will include filters to remove manganese, which can be harmful to infants and children in high amounts, and iron. The water will also continue to be treated with chlorine and fluorinated.

Construction began last September and the plant is expected to be in operation this December.

Currently, water is treated with chlorine and fluorinated at the city's nine well sites, but it's not filtered.

Higher-than-recommended levels of manganese prompted the city to move forward with the centralized water treatment plant.

Manganese, a naturally occurring element, is widespread in central and southwestern Minnesota. It's beneficial to humans at low levels but may affect learning and behavior in infants and young children when concentrations are too high, according to the Minnesota Department of Health. Health effects in children have been measured only in large studies of school-aged children.

The average manganese level in Brooklyn Center tap water was 380 parts per billion in recent years, which is somewhat higher than the 300 ppb limit recommended by the Health Department. The department recommends the even lower level of 100 ppb for formula-fed infants and infants that regularly drink tap water.

"It's certainly one of the more significant considerations for putting in a water treatment plant," said Brooklyn Center City Engineer Steve Lillehaug. "There were other considerations, including the future ability to treat drinking water if other issues occur in groundwater with emerging pollutants."

The new filters will also reduce the amount of iron in the water, which can affect color and taste.

The city is borrowing the money for the water plant through the Minnesota Public Facility Authority loan program at a 1 percent interest rate.

"It was an opportune time to build a water treatment plant and capitalize on having a lower interest rate," Lillehaug said.

Crews with Knutson Construction Services are building the plant on city property on Camden Avenue, near Evergreen Park. The facility will have a brick facade, will be enclosed by a fence and will include a 1 million-gallon underground storage tank.

Residents can anticipate a utility rate increase.

Until the new plant is operational, the city is pumping water only from three of its wells that have the lowest levels of manganese.

The state Health Department has also issued a series of precautions that people with infants and small children can take, including using a charcoal filter or using bottled water, but only if the bottled water has been tested for manganese. Otherwise bottled water should not be considered safer than tap water. Residents with additional questions should consult their physicians.

Shannon Prather • 612-673-4804