Work has begun at the Wastewater Treatment Plant (WWTP) to address immediate operational needs and to continue to meet the water quality requirements prior to discharge to the Columbia River.
Due to the unusually cold and extended winter conditions, primary Lagoon #1 recently “turned over,” bringing solids to the lagoon surface and disrupting the normal sludge digestion operation of the lagoon. Left unchanged, this condition poses an immediate threat to the proper performance of the WWTP.
In consultation with the Washington State Department of Ecology, the work plan involves dredging a portion of Lagoon #1, dewatering the solids and stockpiling the solids onsite on an impervious liner, and allowing the solids to dry out over a likely 3-4 month period. Unfortunately, it is probable that the solids, while drying, will emit a strong odor in the immediate vicinity of the WWTP, depending on winds.
The second part of the action plan will be to accelerate the complete dredging of Lagoon # 2, which was already planned for later in 2017. Unlike the higher pathogen solids from Lagoon #1, Lagoon #2 solids can be dewatered and transported offsite for permitted land application.
The 2017/2018 adopted budget has $2.2 million programmed for lagoon dredging. This amount is anticipated to meet the funding needs for the proposed plan of action.