While it was spring break for some last week, others stayed and enjoyed some of the warm and rainy weather.  The city continued to work on solutions for a recent problem with the wastewater system. Over the past two months, the wastewater treatment plant has received waste that causes it to foam.   This has happened on Tuesdays for the prior 7 weeks and on Wednesday this past week.  The issue is coming from the East side of town since we see the foam in the Rock Creek pump station.  A couple of times it has also been found at the Kanaka Creek pump station.

What are the consequences?  The city does not staff the treatment plant 24 hours a day.  If staff is able to notice a problem right away, we can make changes at the plant to reduce the foaming impact.  When we do not catch the issue in time, it can lead to a foam over of the facility and we need to contact the Department of Ecology (DOE).  Another impact of the foam is that it prevents adequate treatment of the wastewater.  This can lead to the city exceeding its permitted levels of effluent (water going into the Columbia) for BOD (Biochemical Oxygen Demand) or TSS (Total Suspended Solids).  This occurred in late March with a foaming event.  Staff regularly tests the effluent and fecal coliform was not present.  The city is currently under an Administrative Order with DOE and if we continue to violate the permitted effluent limits, it may lead to fines.  On top of that the city is working with DOE to conduct a value planning effort and possibly extend the timeline on some compliance schedule requirements.  When the permit violations persist, it removes any negotiating power we may have.

What are we doing?  Staff has contacted high strength users to see if they have changed processes which may have led to the foaming and none have.  Staff continues to research causes and will start monitoring the sewer lines to determine where the issue may be coming from.  Consultants have also been helpful with trying to determine the cause and working for a solution absent of finding the source of the problem.

If you are aware of any event or activity that may be causing this issue, please contact Eric Hansen, Public Works Director at 509-427-5970.

 

Foaming event at the WWTP on 4/4/18.

Foaming event at the WWTP on 4/4/18.