State Water Board technical staff described the approach they will use to model and cost remedies for facilities flagged as inadequate, proposing modular “solution packages” that combine technical remedial actions with administrative and operational assistance.

Caitlin, a research engineer with the Office of Water Programs, described the team’s approach: identify the presumed underlying cause for a facility’s inadequacy (for example, hydraulic overloading, treatment-process failure, or reporting deficiencies); then assign a set of remedial actions drawn from a menu of common fixes. "We kind of narrowed on this idea of having a solution package, which is gonna be a package of what we're referring to as remedial actions," she said.

Remedial action examples for treatment plants include storage basins, pond desludging, liners, filtration or flotation additions, or full facility replacement; for collection systems, options include spot pipe repair, lining or widespread rehabilitation scaled by miles of pipe, and pump-station rehabilitation. Administrative and operational interventions include technical assistance, interim administrative appointments, contract operator support and SCADA upgrades.

Jonathan Kaplan outlined the cost methodology: derive capital and O&M costs from state engineering reports (approximately 200 DFA reports were reviewed), apply soft-cost multipliers (planning, design, permitting, construction contingency and oversight), calculate net-present-value of O&M over a 20-year window and add managerial/technical-assistance costs. Staff said they will use regional cost adjustments and CPI updates to normalize older estimates and may borrow methodology from the drinking-water needs assessment.

Staff flagged open issues still under development: thresholds for choosing facility replacement versus remedial fixes, non-economic selection criteria (climate resilience, operational simplicity, future regulations), and how to cost and assign managerial/administrative assistance. The team requested technical feedback and said they may consult advisory-group members and wastewater practitioners for better cost inputs, especially for administrative support measures.

Next steps: staff will complete cost curves, finalize soft-cost multipliers and provide more detailed modeling outputs in phase 2 and in office hours for technical review.