Manhattan Beach Resort chief financial officer Tom Grimsley said patrons of a popular cluster of rental units on West Lake Okoboji should be able to use the nearby private beach before the end of the week.
Until then, the public is urged to avoid the immediate area around Manhattan Beach on the west side of West Lake Okoboji. A lightning storm Sunday temporarily knocked out a pumping station causing sewage to back up near the resort.
The sewage backup affected about 12 ground level rental units at the complex. Department of Natural Resources officials say the lightning knocked out a fuse that prevented an automatic telephone dialer from activating to alert Iowa Great Lakes Sanitary District personnel of the problem.
By the time the sanitary district was alerted, the sewage was backing up into the lower floor of the facility and out of the building.
Water and beach samples gathered Sunday and Monday will determine when patrons can return to the beaches and water. Barb Lynch, chief of the DNR's field services and compliance bureau, expects to learn the findings soon.
Grimsley said the mishap came at a peak time for resort operators.
"It really was nothing we could control," he said. "We're cooperating with the environmental people to make sure any damage is minimal."
Lynch said the beach area has been washed down by the fire department and lime has been applied to disinfect the area. DNR officials have not determined the amount of sewage that was released as a result of the power outage.
"Most of the sewage ran out onto the sand of Manhattan Beach where it soaked in, but some people said they saw at least some of the sewage reach the lake," Lynch said.
Only the immediate area around Manhattan Beach was affected by the incident, according to the DNR. Yellow caution tape and temporary orange fencing roped off the beach area for much of the day Monday. She will keep the beach closed pending test results, but Lynch didn't expect much, if any, harm to the nearby lakes.
Sunshine and warm weather Sunday and Monday may help dissipate any bacteria that may have reached the lake, according to the specialist.
"There's going to be a lot of cleanup work in the rental units where this occurred, but we're fortunate that this is the only area on the lake that was affected by the storm," she said. "The Great Lakes Sanitary District also worked very quickly to get the situation taken care of once they were notified of the problem. Everyone has been patient and cooperative."