Park Rapids to investigate clean water solutions
Park Rapids is running out of options for finding clean water from wells in the city and is looking into water treatment facilities.
City engineer Jon Olson and colleague Bala Vairavan, with Ulteig Engineers in Fargo, N.D., presented a draft study to the Park Rapids City Council Tuesday night. The goal of the study is to evaluate the city's well water sources and look into water blending and alternatives, such as water treatment facilities.
They explained that the city uses well water primarily from shallow wells 5 and 6 but includes water from deep well 8 during periods of high demand.
Water from the shallow aquifer has been seeing increasing levels of nitrates, which is a health concern. The deep aquifer has increasing levels of iron, which, while not a health concern, creates staining and taste concerns.
The recommended iron concentration is less than .3 mg/L. The iron level in well 8 has increased from .57 mg/L in 2009 to 2.3 mg/L in 2011.
The system is operating at peak capacity and is able to meet maximum demand due to water storage. The average daily demand is 430 gallons per minute and maximum daily demand is 859 gallons per minute.
Olson said the desired improvement would be to install another deep well and blend this with the existing shallow wells. The capacity would exceed short-term and long-term demands.
However, this well would also likely have high iron levels.
The estimated cost is $410,000 and it will meet the health-based requirements for city water. Olson noted that if the nitrate levels in the shallow wells continued to rise this option could become unfeasible at some point.
Alternative solutions include pressure filtration systems to treat the water and eliminate concerns for nitrates and iron. Another option is an ultra filtration system or a conventional water treatment plant.
Costs for treatment systems range from about $2.4 million to $7.19 million.
The city's public works director, Scott Burlingame, said there is an urgency to fixing these water issues and high iron concentrations aren't an acceptable option.
"When we turn on well 8 it turns everything yellow," he said.
The system will also become full of iron and leave remnants in the pipes, Burlingame said.
The next step is to have the engineers move forward with a preliminary engineering report for a pressurized filtration plant.
The city will seek out funding possibilities as well.