Tumwater's smart cover technology helps avoid sewer overflow

Tumwater’s sewer monitoring system prevented an overflow in Tumwater’s sewers days before Christmas, data from the city’s water resources department shows.

The city employs a “smart cover” system to monitor the level of wastewater in the sewers using a sensor installed on the cover of a maintenance hole.

The sensor automatically notifies city staff when the wastewater level is up so that they can respond to possible overflows.

Data from the monitoring system showed the wastewater level spiked around December 24, reaching around 34 inches below the maintenance hole cover. The system alerts city staff that the wastewater level is high when it comes 44.5 inches below the cover.

Water Resources Director Dan Smith told The JOLT that had the technology not been deployed, large obstructions caused by fat, oil, and grease would have resulted in an overflow.

The monitoring system was first deployed in April 2022 along Somerset Hill Drive at Percival Creek. Smith said that they have not had any overflows since the installment of the sensors.

The city has since installed two additional units, with the department planning a fourth one. Smith explained that in choosing the location of these sensors, they prioritize remote areas or locations with the greatest risk of sewer overflows.