Stanley will soon be getting a new central water treatment plant off Church Street to better enhance water quality through more reliably removing of iron, manganese, and hardness from city drinking water. Plans for the new treatment plant were shared at the Monday, Sept 15 Committee of the Whole. Project bids closed earlier this month, with bid awards still to come and project completion expected in November 2026.
City of Stanley Water Operator In Charge Jon Strand said the new central water treatment plant was required due to obsolete treatment equipment.
“The new Central Water treatment plant is required due to obsolete 1970 treatment equipment (iron and manganese filters, chloride-based softeners and chemical feed equipment),” he said. “The old treatment equipment has been utilized for 55 years and has frequent servicing needs. The old soften equipment relies on a salt brine system that discharges chlorides to the wastewater treatment plant. Chlorides are now being regulated to smaller amounts which requires the City to use a newer technology.”
Natural minerals present in the aquifer and causing water hardness will be removed through reverse osmosis in the new plant. The plant will also include stormwater ponds and be slightly higher than the present plant due to changes in what the DNR considers a 100 year storm for floodplain metrics. A 100 year storm is one that has a one percent (0.01) chance of happening in any given year.
The new central water treatment plant meanwhile will be built with an addition on the north side, as Strand said the plant must be in operation at all times. A small N&I pond some 4 1/2 feet deep would be included as well to remove suspended matter, the city using three feet of the pond each year. A 2013 plant addition will stay with the new construction but have a raised floor on the tank, with a stairway to stay as well on top of the reclaim tank. The project will also replace the Well 3 wellhouse which is an older 1940’s building that is in need of replacement.
Also included for removal with the new plant meanwhile are PFAs present in the central treatment plant’s source aquifer. PFAs is a generic term for a set of manmade chemicals with flourocarbon bonds historically used for manufacturing but since tied to health risks, including cancer.
The source of the aquifer’s PFAs is unknown, being somewhat pervasive in the modern environment. Local PFAs levels are not considered hazardous under current standards set by the Wisconsin Department of Public Health Services or United States Environmental Protection Agency. Removal will take place via positively charged resin to attract the negatively charged (anion) PFAs, with later removal to a landfill or incinerator.
Strand shared more information on PFAs and its removal from city water.
“At the Central Water Treatment Plant PFOS (perflourooctane sulfanate) is present at 0.81 ng/l but after Reverse Osmosis Treatment the blended level will be approximately 0.4 ng/l which is actually below the laboratory level of detection amount of 0.48 ng/l,” he said. “The drinking water maximum amount allowed is 4 ng/l.
“For PFOA (perflourooctanic acid) the level in the aquifer is 0.87 ng/l but after Reverse Osmosis Treatment the blended level will be approximately 0.4 ng/l which is below the laboratory level of detection amount of 0.47 ng/l. The drinking water maximum amount allowed is 4 ng/l. These are very low levels, one ng/l is equal to 1 part per trillion.”
The new central water treatment plant awaits bid awards to begin construction, a rate increase helping to pay for construction.