Lincoln City’s grease problem came to head Wednesday. March 10, when a. blocked sewer line led to the discharge of 50,000 gallons of sewage onto City-owned woodland just south of Devils Lake. (See Spill Report to DEQ)
City workers discovered the spill eight days after someone passing the wooded area south of the SE 3rd Street reported a foul odor.
Lila Bradley, the City’s public works director, said the spill was caused by a grease blockage in a sewer line about a mile south, at S.E. 19th Street, and that the backed-up sewage had diverted into a abandoned line that crosses the woodland.
“If it had stayed in the area of the blockage, we would have found it much faster.” she said. “It was an investigative process to find it.
The City notified the Oregon Department of Environmental Quality (DEQ) about the spoil and posted the area to warn people of the contamination.
Bradley said the spill is contained in the woodland and not flowing toward the lake.
City waste crews used a high-powered vacuum to clear sewage from the abandoned pipe and, as much as possible, from the spill site before adding lime to the area.
Lake Manager Paul Robertson said adding lime will raise the PH of the sewage, killing pathogens such as E.coli.
“Generally, it will leave a burn on the soil,” he said. “Grass will have a hard time growing there for a while”.
Robertson said that, over time, the woodland ecosystem will absorb the spill, making use of its nutrients.
“It’s just the same as a bear in the woods,” he said. “Or an animal that dies in the woods – nature absorbs it”.
Meanwhile, City workers have removed the S.E. 19th Street blockage that caused the backup and have resealed the abandoned sewer line to prevent and future diversions of waste.
Bradley said grease is a constant problem for her department, with workers regularly having to climb down into wet wells at the City’s sewage lift stations and remove buckets of coagulated grease by hand.
In 2004, the City adopted a grease ordinance requiring food service establishments to install grease traps and prohibiting the use of waste disposal units that discharge into the sewer system.
Bradley said the public works department checks to make sure grease traps are being cleaned regularly and that new staff members are trained in their use.
She said most restaurants are very cooperative but that grease discharged from residential properties is also a problem.
She said S.E. 19th Street is home to two large apartment buildings, which tend to produce a lot of grease.
The City produces flyers in both English and Spanish listing substances that should not be put down the drain. Copies are available at City Hall.
Bradley said the public works department also provided grease containers that residents can place next to their sinks to collect fats and oils for disposal in the trash.
Used cooking oil can also be dropped off at the North Lincoln Sanitary Service’s recycling center, at 1726 N.W. Highway 101.
The oil, which must still be in liquid form when deposited, is used as an ingredient for biodiesel fuel.