A significant spill of partially treated wastewater, likely storm-related, happened in Sonoma County last weekend, but officials seem to be downplaying the matter.

The spill began Friday evening and continued into Saturday, according to officials with the Sonoma County Water Authority, and it involved approximately 277,000 gallons of "secondary treated wastewater" at the Russian River County Sanitation District Treatment Plant south of Guerneville.

According to the agency, a portion of the spill was contained within treatment plant property, however some of the spill traveled about a third of a mile through a forested area and reached the "mainstem of the Russian River."

Main Street in Guerneville is at the center of the map, showing the water district.

Officials say they have not observed any impacts on wildlife so far, and environmental specialists have been dispatched to assess any impacts.

Secondary treated wastewater is sewage that has had large, inorganic material removed, and much of the organic material is biologically neutralized, according to officials. It has already gone through one stage of treatment, flowing through clarifiers to remove solids, but some solids remain until it is clarified again in the third and final stage of the process.