COTTONWOOD — Cottonwood residents know their community doesn’t have the best tap water, Cottonwood City Administrator Teather Bliss said. But it was a surprise this winter when city staff learned that Cottonwood’s water supply had unusually high levels of the mineral manganese.

“Right now your manganese levels are probably the highest ones I have seen in southwest Minnesota,” engineer John Graupman told Cottonwood residents at a public hearing Tuesday night. “In recent years, the Department of Health has started to issue a health advisory limit to communities. You are well above what that health advisory limit is.” The city’s manganese levels were at 1.5 milligrams per liter, compared to the state health advisory limit of 0.2 milligrams per liter, presenters at the hearing said.

Next week, the Cottonwood City Council will be faced with making a decision on how to address the problem. One possible solution could be connecting to the Lincoln Pipestone Rural Water system, residents learned at the public hearing.

The hearing on Cottonwood’s water drew close to 100 people to the Cottonwood Community Center on Tuesday, Bliss said. The event was also livestreamed. In addition to city staff and members of the city council, representatives from LPRW and engineers from Bolton & Menk were at the hearing.

Manganese is a naturally-occurring mineral that is often found in ground water. The body does need some manganese to be healthy, but high levels could lead to health problems, according to the Minnesota Department of Health.

Manganese isn’t a contaminant that is required to be tested for, said Kim Larsen, supervisor of the Community Public Water Supply Unit at the MDH. However, in recent years, the Environmental Protection Agency has taken a closer look at manganese, Larsen said. For example, having high levels of manganese in drinking water could pose a health risk for infants who are already getting enough manganese in their formula, she said.

Bliss said Cottonwood might possibly be required to issue a public health advisory from the MDH about the manganese in its water. However, at this point, she did not know what that advisory would say.

The levels of minerals in Cottonwood’s water were discovered within the past few months, as the city was looking into other infrastructure improvements, Bliss told the Independent this week. Cottonwood is currently making an $8 million state bonding request to pay for the first phase of a project to replace aging sewer and water lines in parts of the city.

“We were working on gathering information for our engineers, in regards to our water and sewer,” she said. Water testing was part of that process.

In addition to high levels of manganese, Cottonwood also had moderate levels of iron and high levels of sulfates and sodium in its well water, Graupman said.

There were some possible alternatives for Cottonwood to reduce levels of minerals and sulfates in city water, Graupman said. One option could be to connect to the LPRW system instead of using city well water. If the city went that route, there would be a both a buy-in cost and a cost for building the connection to the system.

If Cottonwood connects to LPRW, they could still use the city wells for emergency purposes like fire response, presenters said.

The city could also build a filtration plant to lower the levels of manganese and iron in the water supply. However, this would have “a fair amount of cost” for the city, and not address water hardness, or sodium or sulfate levels, Graupman said. The third option would be to use reverse osmosis to soften Cottonwood’s water. This option would also have an effect on Cottonwood’s wastewater system.

Presenters at the hearing said all three solutions would carry costs for the city. The total annual cost of connecting to LPRW would be about $453,000, or $265,000 if the city gets funding help from an Emerging Contaminant Grant. The cost of building a filter plant would be $592,000 a year, or $390,000 with grant funding. The cost of using reverse-osmosis water softening would be $800,000 a year, or $599,000 with grant funding.

While there were possible options to help Cottonwood cover the cost of addressing water supply problems, but the city would need to make a decision soon, Bliss said. If Cottonwood joins LPRW before June 1, they would have a lower buy-in cost. The city could also apply for Emerging Contaminant Grant funding, but the deadline to apply for the funding is in May, she said.

Bliss said she didn’t know why Cottonwood had never been informed about the manganese levels in city water before. The state had done water sampling in southwest Minnesota in 2010 as part of a general water chemistry project, but Cottonwood’s water was not tested in that project, she said.

Larsen also said she wasn’t sure why Cottonwood’s water was not sampled in 2010.

“We didn’t get to all the (water) systems,” she said.

Staff from the MDH did come to Cottonwood on Wednesday to take water samples, Bliss and Larsen said. More samples will also be collected two to three weeks later.

“I expect there will be more information to come,” Bliss said.

In the meantime, the Cottonwood City Council will meet at 5:30 p.m. on March 21, to act on the city water question, Bliss said.