Sean C. Morgan
Of The New Era
A filter at the city’s wastewater treatment plant apparently wasn’t thick enough to keep odors from escaping the plant and reaching the nostrils of residents and visitors to Sweet Home.
Thursday and Friday, based on information provided by a consultant from CH2M Hill, OMI, Inc., which operates and manages the plant, the amount of hog fuel used to filter the odors from the offending basin was nearly doubled.
The consultant, the head of odor remediation with CH2M Hill, identified the apparent source of the odor last week.
“He was able to determine the filter needed adjusting,” Public Works Director Mike Adams said.
This year, the city had the filter and a dome installed on the basin, but the odor has continued to escape.
The city wanted someone to come in and take samples around the wastewater treatment plant to identify the source of the odor, perhaps another part of the plant, Public Adams said.
The consultant identified odor still escaping through the filter and recommended that the city increase the thickness of the filter from roughly 2.5 feet to more than 4 feet, approximately 30 cubic yards of hog fuel, Adams said, and the city will add even more hog fuel.
A set of perforated pipes runs through the filter, keeping the hog fuel damp. OMI installed an additional level of the pipes above the first one.
The city is trying to reduce the odor to a quantifiable level that is acceptable, Adams said. Samples have been sent to a lab for identification.
Once the odor-causing agent is identified, the city may be able to counter it, he said.
In a couple of weeks, the consultant will return to run further tests and find out if the filter adjustment has been successful, Adams said. “The person we had is confident that most, if not all of the odor, should be taken care of.”
Of course, with what’s happened so far, Adams is hesitant to make that a guarantee at this point, he said. Still, there is a noticeable difference in the intensity of the odor right at the filter.
The testing cost approximately $1,000. The hog fuel and changes to the filter were handled as part of the city’s contract with OMI.