MILWAUKIE -- Excessive rainfall has caused sewers to overflow in some areas, creating a potential public health hazard, officials said Tuesday.

The rain prompted Water Environment Services to bypass treatment processes at the Kellogg Wastewater Treatment facility. Flows will continue to be bypassed until rains relent and normal flows resume. The Kellogg facility is located at 11525 SE McLoughlin Blvd in Milwaukie.

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As result of this bypass, untreated wastewater was being released into the Willamette River. WES officials estimate the Kellogg Facility was receiving as much as 20 million gallons per day on Monday afternoon. The plant is rated for an average daily flow of half that amount.

Treatment facility staff has been working around the clock since 8:30 p.m. on Sunday to manage flows and maintain treatment.

Signage has been placed along the Willamette River and the mouth of Kellogg Creek notifying citizens of the spill.

Also due to the heavy rainfall, two manholes began surcharging at the nearby Jefferson Street Boat Ramp. Milwaukie wastewater workers placed barricades and cones around the manholes and closed the entrance to the boat ramp until further notice.

One of the surcharging manholes is located on the boat ramp itself and the second is located on the south side of Kellogg Creek near the treatment plant. Due to the close proximity of the manholes to the Willamette River and Kellogg Creek, untreated wastewater is flowing into the river and creek. These surcharging manholes prevent sewage from backing up into nearby businesses and residences.

Once stormwater flows subside, Milwaukie workers will replace the manhole lids and conduct a site assessment to determine whether or not a cleanup effort is necessary.