There’s something leaving the water in St. Louis Park
One of the most prolific jokes in St. Louis Park is that “there’s something in the water.”
The saying is true, though St. Louis Park workers strive to remove substances before they reach residents’ faucets.
St. Louis Park actually adds a form of manganese to some of its water – temporarily – in an effort to remove radium, which became problematic in past years.
Manganese is an element found naturally in drinking water, food, soil and the air throughout the state; however, consumption of too much may be harmful, according to the Minnesota Department of Health.
While small amounts of manganese are necessary to maintain a healthy diet, infants are more at risk because they absorb more of the element as they grow, according to the department.
The Brooklyn Center City Council learned last month that average manganese levels in that city exceed the Minnesota Department of Health maximum.
“The message we want to have as a city is there is an advisory that there is manganese in the drinking water and it may be harmful,” Brooklyn Center Public Works Director Steve Lillehaug said. “Brooklyn Center is and has taken immediate steps to reduce risk and we are exploring options to further reduce risks,”
Meanwhile, St. Louis Park uses a form of manganese, hydrous manganese oxide, in its efforts to lower radium levels. The additive attracts radium in St. Louis Park’s water at four water treatment plants. After the radium “sticks” to the chemical mix containing manganese, St. Louis Park filters it out through a backwash process, said St. Louis Park Supt. of Utilities Scott Anderson.
Along with water treatment plant rehabilitations that wrapped up last year, the process has helped keep St. Louis Park’s radium levels below Minnesota Department of Health levels since 2008. In that year, the city had a violation at Water Treatment Plant No. 6, 4241 Zarthan Ave. in St. Louis Park.
As for the manganese, Anderson said, “There’s some leakage through there, but the levels are basically what we refer to as trace amounts of the manganese.”
St. Louis Park provides official samples from its six water treatment plants to the Minnesota Department of Health. Water test results in 2003 began indicating increasing levels of alpha emitters. Alpha radiation has been linked to cancer and other diseases.
Radium emits several types of radiation, including alpha radiation and gamma radiation, according to the U.S. Environmental Protection Agency. Radium occurs naturally in the environment at low levels in “virtually all” rock, soil, water, plants and animals, according to the EPA.
“The concentration of radium in drinking water is generally low, but there are specific geographic regions in the United States where higher concentrations of radium occur in water due to geologic sources,” an EPA fact sheet states.
The reason for the increase in 2003 in St. Louis Park is unknown, Anderson said. Nevertheless, the city began working with Minnesota Department of Health to establish a plan of attack to lower the radium levels.
St. Louis Park hired the Howard R. Green Co. to study the levels of radium and alpha emitters that year.
The company recommended that St. Louis Park upgrade the filtration processes in four city water treatment plants and use the technique using hydrous manganese oxide.
The EPA has identified hydrous manganese oxide as a small system compliance technology for removing radium. The method can remove up to 90 percent of radium, as well as arsenic, according to the agency.
The hydrous manganese oxide method is very effective for systems where water is not detained for treatment for long, like in St. Louis Park, said Karla Peterson, community water supervisor for the Minnesota Department of Health. The system also filters out the manganese itself.
“Even though they’re adding manganese as part of the process, by the time it leaves the treatment plant there’s practically no detect from manganese,” Peterson said.
About a dozen water treatment plants in Minnesota use the process, Peterson said. In the metro area, Champlin also uses hydrous manganese oxide.
In another effort to reduce radium and increase water quality, St. Louis Park also launched its water treatment plant rehabilitation program in 2003.
The plan’s implementation wrapped up in 2012 with the rehabilitation of Water Treatment Plant 6. Costs for the rehabilitation of each of the city’s six plants varied from $188,100 for Water Treatment Plant 4, which was built in 1991 and needed fewer upgrades, to $854,400 for Water Treatment Plant 1.
To finance the approximately $3 million project, St. Louis Park sold municipal bonds and paid back investors using its water revenues.
“This investment is providing the city with higher quality water, more dependable service and has extended the water treatment plants for many years,” Anderson said.
Although Anderson said water treatment plants in St. Louis Park have not violated health department standards since the city began using the hydrous manganese oxide process, the city did hire a consultant to help staff improve levels at one plant recently.
“We’re always looking to improve it,” Anderson said. “This one wasn’t working quite as effectively as we wanted it to. We have not exceeded (health department levels), but we always want to keep it below.”
He added, “In our job, I just make sure the water’s safe to drink and there’s plenty of it.”
Brooklyn Center Community Editor Katy Zillmer contributed to this article. Contact Seth Rowe at firstname.lastname@example.org or Katy Zillmer at email@example.com.