Chehalis City Council received a mid-course update on the city' wastewater comprehensive plan on Monday, Aug. 11, 2025, as consultants from KJ Engineering reviewed preliminary risk findings, capacity projections and options for biosolids and reclaimed-water management. The presentation covered a 20-year planning horizon and next steps toward a final capital improvements program that will be submitted to the Washington State Department of Ecology.

KJ Engineering's interim project lead, Andrew, said the plan "does satisfy a requirement of the Washington Administrative Code" and is intended to "position the facility for long-term resiliency and ongoing compliance with current and potential future regulations." He described the project as a multi-phase effort that includes data collection, condition assessments, system analysis and a risk-based prioritization exercise.

The consultants said the plan uses a three-factor risk calculation (consequence of failure x business vulnerability x likelihood of failure) developed in multi-day workshops with city staff. The highest-priority items to date include electrical equipment at the plant (motor control centers and some switchgear nearing end of life), the plant's programmable logic controller and SCADA process-control systems, and biosolids handling and stabilization processes. "There's a lot of opportunity for improvement with the biosolids handling at the water reclamation facility," the presenter said.

KJ noted that two collection-system pump stations, Prindle and Riverside, scored high on consequence-of-failure because all wastewater flow passes through them; the consultants said those pump stations are in relatively good condition, so once likelihood-of-failure is applied they may move lower in a final priority list.

On capacity, consultants reported projected population and flow increases for the urban growth area are within the plant's permitted maximum-month flow. However, pounds-per-day biological oxygen demand (BOD) is the limiting treatment criterion; the analysis projects that plant loadings could reach about 85% of permitted BOD capacity within roughly five to 10 years under the current growth assumptions, a level that KJ said should trigger planning for capacity improvements.

For biosolids, presenters outlined a set of alternatives the report will analyze: maintaining the current lime pasteurization baseline (which consultants said creates a difficult work environment and a product unsuitable for local beneficial reuse), dewatering and hauling to landfill, adding digestion upstream of dewatering to enable Class B land application or hauling to a permitted beneficial-use facility, or adding Class A treatment after dewatering (for example thermal drying or composting) to enable local reuse. The consultants also discussed emerging thermal technologies such as pyrolysis and gasification as potential PFAS-mitigation pathways.

On reclaimed water, the study focuses on potential irrigation uses, including options for the city's poplar tree farm and nearby users such as Riverside Golf Club; KJ said it is intentionally avoiding overlap with separate feasibility work by other parties.

KJ told the council the final plan will include a prioritized capital improvements list, a financial implementation analysis and a package for Department of Ecology review; the consultants said an upgrade timeline under discussion would place some investments in 2027 and that having the comp plan in place strengthens eligibility for state and federal grant and loan programs.

City staff and council members asked for clarification about the electrical findings (consultants explained the issues are primarily motor control centers and switchgear nearing typical 20'to'25-year life cycles) and about whether inflow-and-infiltration (I&I) effects are incorporated into the capacity analysis (consultants said I&I primarily affects hydraulic capacity and the plant's limiting criterion in this study was BOD).

Next steps described by KJ include completing the remaining condition assessments, finishing a high-level lift-station capacity analysis, completing alternatives analyses for biosolids and reclaimed water, and producing the final comp-plan report for Department of Ecology submittal.

The council did not take formal action on the comp-plan update at the meeting; the presentation served as an informational mid-course report and preview of capital priorities and funding needs.