MOSES LAKE — The Grant County Health District declined to extend a no-contact advisory for the waters of Moses Lake on Friday, seven days after a sewer line breach under the water was discovered.
The decision to lift the advisory was based on water sampled from a single location, near the original breach, which showed acceptable levels of fecal bacteria, agency administrator Theresa Adkinson said in an interview with the Columbia Basin Herald.
Samples, which are taken by the city staff and analyzed by the Health District, have been taken in other locations. Adkinson said those results are expected to arrive Monday at the earliest.
Pending further results, the Health District still recommends that people stay out of the lake waters at Blue Heron Park, where bacteria would be most likely to drift, Adkinson said. Swimming is still not recommended in any portion of the lake due to blue-green algae.
Adkinson said that although the Health District operates with an abundance of caution, and the possibility remains that a no-contact advisory could be reinstated pending further test results, the district made the decision to lift the advisory based on the data available to them.
“We had a lengthy conversation with our health officer about that,” Adkinson said. “Because we had acceptable results already, because we had a seven-day window, we felt like it would be better to have the advisory out there rather than close the lake without having data.
“We run on data, and when you don’t have information yet, we’re just making sure that people make informed decisions about the waterway.”
However, in a press release shared with media and publicly on social media by other agencies, the City of Moses Lake suggested a broader array of data had been analyzed before the no-contact advisory was discontinued.
“Most of Moses Lake is safe for boating and irrigating ... according to information provided by the Grant County Health District on Friday,” the city wrote in a press release disseminated Friday evening. “The newest lake samples taken this week showed most of the affected areas had improved.”
City officials won’t be available to provide clarification until Monday, according to city communications staff.
The test results received by the Health District showed normal levels of fecal matter bacteria, such as E. coli, Adkinson said. Such bacteria are naturally present at low levels in bodies of water due to wildlife, Adkinson noted.
The seven-day no contact advisory for Moses Lake was issued Aug. 28 after a baseball-sized hole was found in the aging Knolls Vista Siphon, which runs sewage under the lake to a wastewater treatment facility.
City wastewater employees installed a steel band around the breach to stop the discharge about five hours after discovery.
The city estimated that around 64,000 gallons of raw sewage was released into the lake during those five hours. At the time of the breach, city staff were uncertain whether sewage had only recently started to be released or if it had only just been discovered. City staff were not immediately available for comment Saturday.
Last week’s repair was the second for the decades-old pipeline in the last two years, after an exposed portion of the pipe was reportedly vandalized during a recent winter, according to city staff.
Due to the age and recent history of damages to the Knolls Vista Siphon, the city is planning immediate upgrades to the collection system in the Knolls Vista and Sage Bay tributaries, according to the press release. A preliminary design meeting with the City Engineering Division was held on Wednesday and the city council will consider issuing an emergency declaration to replace the sewer main at the Sept. 10 council meeting.
Once finalized, the upgrades would start with bypassing the Knolls Vista Siphon by installing a gravity main directly to Sage Bay Lift Station. Sage Bay Lift Station had the capacity for additional flows, according to the press release.
The second phase of the project would include the installation of a forced main to the existing main, connecting downstream of Sage Bay Lift Station. During the final stage, a parallel force main will be added from Sage Bay Lift Station across the lake. The force main would allow for emergencies and increased flow capacity, according to the press release.
Emry Dinman can be reached via email at firstname.lastname@example.org.