HERMISTON — A sewer line backed up along West Hartley Avenue in Hermiston on Wednesday, March 31.

Assistant City Manager Mark Morgan said wastewater backed up into the basement of two homes on the 600 block of West Hartley Avenue during the evening. The city paid for O So Kleen to clean up the homes, something Morgan said is standard when a city line was at fault. The cause of the backup was roots from trees in the vicinity of Third Street and Hartley working their way into the city’s sewer main and blocking it.

Morgan said root intrusions are common, and city crews clean more than 10,000 feet of sewer main each month to address the problem. He said one of the first sewer projects after the city created its Capital Improvement Plan two years ago was to run a video camera down a “large percentage” of the city’s sewer lines to determine causes of clogging and figure out how to better fix and prevent them. The city now has $1.9 million in sewer main replacements planned for the next five years.

The city asks residents to never dump grease down their drain or flush “flushable” wipes or baby wipes down the toilet. Wipes get stuck on roots and then fats, such as bacon grease, congeal around the wipes, creating what the wastewater industry calls “fatbergs” that clog sewer mains.

A March 26 article by Bloomberg News reported that wipes flushed down the toilet previously caused cities in the United States about $1 billion annually to clear out blockages, and cities are reporting an increase in those blockages since the pandemic began.