Who is Potentially Impacted by the MSTP Wastewater Outfall Pipe in the Molalla River?

Coleman Ranch Impacts upon Molalla River

In late 1999, an agreement was signed between Coleman Ranch and the City of Molalla. The agreement called for Molalla to pipe their recycled sewage treatment plant wastewater, to be used during half of the year as irrigation for pasture at the ranch. The pipe used to deliver this water was later extended, creating a new Molalla sewage treatment plant (MSTP) wastewater outfall. Thus, while all MSTP wastewater was pumped into Bear Creek prior to 2006, once the new outfall was finished, the wastewater was pumped into the Molalla River. The northbound river flow is indicated by the blue arrow in the image above.

How does this impact local citizens? Well, during hot summer days, locals commonly swim in the Molalla River, just upstream from the Highway 211 bridge (see above aerial view, at “1”). People park near the 211 bridge and hike in, using trails on both the east side and west side of the river. Another popular site, for those willing to hike further, is at “2” above, where there is a rope swing over a pool. Both of these swimming sites are downstream from the MSTP outfall pipe, which is at the orange square (see “3” above).

MSTP is not allowed to discharge during the summer months. However, the same outlet pipe is used to supply treated sewage water to Coleman Ranch, for summer irrigation of cattle pastures. So, water quality for swimmers depends on the effectiveness of the valves on the MSTP discharge line. Also, over the years, MSTP has had repeated events where the ponds are too full and, due to heavy rain, MSTP has needed to open the valves and discharge into the river. Oregon DEQ is helpless to deny their requests, as MSTP cannot let the ponds overflow into the Bear Creek drainage. Consequently, it is conceivable that some may swim in the Molalla River in late Spring or early Fall, unaware that the water includes wastewater discharged  by MSTP.