Wastewater Discharge to West Okoboji Lake
MILFORD – A break in a force main sent untreated wastewater into West Okoboji Lake over the weekend.
The break, on the southeast corner of the lake, was discovered at 11:30 a.m. Monday. However, a DNR environmental specialist on site said it looks as if the wastewater has been discharging for a few days.
After a report from a resident who heard water running, staff from the Iowa Great Lakes Sanitary Sewer District investigated and found untreated wastewater discharging into a culvert. The culvert runs under the street and into a grass waterway. Then it runs into a ravine where the wastewater is diluted with surface water as it flows about one-fourth mile to the lake.
“We appreciate when residents notice and report unusual things,” said Bryon Whiting, a DNR environmental specialist. “Due to the location of this break, the bypass could have occurred for much longer. People need to report these types of observations.”
Staff from the DNR estimate about 35 gallons per minute of wastewater was being released until about 2:30 p.m. Monday. At that time, the sanitary district began pumping and hauling wastewater to the treatment plant. A small amount of wastewater continues to bypass.
Whiting said people should keep children and pets away from the shoreline and out of the water for the next 48 hours in the Wheelers Woods area. Also, people who plan to swim at Terrace Park beach should be aware that bacteria counts could be elevated for the next 48 hours and should use their own discretion.
DNR staff took water samples near the discharge to test for bacteria and other pollutants. They also notified residents who live in the immediate area of the discharge.
The DNR has notified the three drinking water plants which draw water from the lake so they can protect their water systems: Milford Municipal Utilities, Central and Wahpeton water supplies. Normal water treatment processes at these plants should adequately protect residents’ drinking water.
The DNR will consider appropriate enforcement action for the wastewater discharge.