After year of repairs, Mattawa sewer plant soon to be back up and running

MATTAWA — Repairs should be completed early next year on the wastewater treatment facility in Mattawa, badly damaged in an early-morning fire Jan. 9.

While the origin of the fire has been linked to an electrical panel in the blower room, the exact cause of the fire is unknown.

The exact time the fire started also is unknown, but City of Mattawa Public Works Director Juan Ledezma has stated that officials estimate it to have started around 2 or 3 a.m., based on the size of the room destroyed and how hot the fire was when the fire department arrived on scene.

On the evening of Jan. 8, the area directly west of Mattawa, extending down past Desert Aire, experienced a power outage. The outage started at 6:51 p.m. and affected 1,608 people, according to Ryan Holterhoff, Grant County PUD public affairs officer, in an interview in January 2020. Power was restored to the area at 10:08 p.m.

But the load of all the heaters in the area attempting to all turn back on at the same time was too much for the system to handle and another power outage occurred at 10:24 p.m. The second outage only affected 300 customers. Power was totally restored to the area after 6 a.m. the next morning.

The wastewater treatment facility was one of the locations affected by the power outage. The electrical outage near the 2,000 square-foot wastewater treatment facility was caused by a low oil alarm on one of the transformers at the substation. Power was out for a little more than three hours while crews temporarily transferred customers over to a different transformer. Repairs to the offending transformer were completed and customer loads routed back as normal at 6:09 a.m.

Meanwhile at the Mattawa Wastewater Treatment Facility, a fire started in the electrical panel that was located in the blower room.

It is speculated that once the fire ignited, it spread to nearby fuel, such as oil and aerosol cans, that caused the fire to get hot very quickly. When fire crews arrived on the scene, the exterior of the building was more than 600 degrees Fahrenheit, according to information obtained from Grant County Fire District No. 8 Fire Chief David Patterson in the days immediately following the fire.

A public works employee, Kevin Webster, attempted to check on the facility remotely and was unsuccessful. Ledezma said Webster wasn’t surprised, due to the power outage.

Webster, who was not on call that night or scheduled to be at the plant the next day, decided to check on the facility remotely the next morning.

However, Webster was still unable to check on the computer remotely. He went to the treatment facility, arriving around 5:30 a.m. He noticed the area around the facility looked foggy. Realizing the fog was really smoke coming from the facility, he called 911.

When fire crews arrived, the thermal cameras used by the fire department showed the building exterior to be more than 600 degrees. In the January interview, Peterson said it took an hour and a half to extinguish the fire and another hour to mop up. The blower room portion of the wastewater treatment facility was a complete loss.

In the process of getting the facility up and running, some sewage spilled between 8 and 9:30 a.m. and contained untreated liquid waste.

In the five-day report required by the Washington State Department of Ecology, Ledezma said an estimated “7,000 to 10,000 gallons of sewage was spilled based on the time it took to set up pipes and trash pumps as the WWTP (wastewater treatment plant) had no source of power.” Of that, an estimated 2,000 gallons was removed from the ditch between the facility and Road U. Working with the Grant County Health Department, the spill was cleaned up by 4 p.m.

As the city fixes the damages caused by the fire, it is taking measures to prevent a fire from happening again. Instead of having the electrical panels in the same room as the blowers, a separate electrical room is being built and air conditioned. Both the power and internet connections are getting backups.

“We want a double safeguard to prevent anything like this from happening again,” Ledezma said.

Once the rebuild is complete, the City of Mattawa will be doing some previously-planned upgrades on the facility’s clarifiers.