Batavia staff: Wastewater plant rehabilitation nearing completion; work focused on final electrical, HVAC and paving

Jerry, the project presenter, gave the City Council an update on the wastewater treatment plant rehabilitation project, saying crews have moved into final electrical, HVAC and equipment start-ups and site paving preparation as the plant nears startup.

“On paper 67% of their schedule because they're not scheduled to be finished until next year,” Jerry said, summarizing the contractor's schedule and noting that construction costs to date total just over $41,000,000 and about 93% of the construction budget has been spent. Jerry said the contractor submitted change order No. 5 (about $67,000) and that one or two additional change orders are expected as small items are refined during the finish work.

The presenter described progress by major area: Headworks (HVAC, makeup-air units and equipment start-ups), primary clarifiers (coating, electrical terminations, actuator installation), primary clarifier diversion structure (concrete fillets and slide‑gate operators) and the primary clarifier control building (PCCB). He showed photos of pavement removal, new access roads and electrical work for a motorized gate at the south entrance.

Jerry said the project team has completed final clarifier rehabilitation and is finalizing piping, coatings and control panels; the odor-control system and clarifier lighting are in place and the team is preparing sludge-handling areas and some interior wiring. He showed aerial photos comparing June 1 and July 18 progress and noted sidewalk and grading work at the south end of the site.

On regulatory drivers, Jerry reminded the council that the city must meet a permit limit of 0.5 milligrams per liter (mg/L) total phosphorus by 2030, which is the primary reason for the tertiary filtration portion of the project. He said the expansion from a 4.2 million gallons per day (MGD) design to a 4.9 MGD future capacity triggers an anti‑degradation review, which limits the receiving stream to no additional loading; that requirement, not just flow projections, shapes decisions about process selection for nitrogen and phosphorus removal.

Jerry also reviewed planning assumptions and flow projections. He said recent community development trends push projected annual average flow toward the facility’s 4.9 MGD design point by the middle decades of the century, and that rainfall and groundwater infiltration remain important variables in estimating future flows. He described how the city completed sewer separation in a major area in 2020 and noted that seasonal rainfall increases infiltration into the collection system.

On future regulatory issues, Jerry said state permitting will require PFAS testing in influent, effluent and biosolids for permit renewals in the coming round; Illinois has not yet set numeric PFAS limits but the state and regional groups are researching pathways and source reduction. He said microplastics are principally a concern for membrane systems such as reverse osmosis, which the city is not using now.

Council members and the mayor asked about tours, timing and startup. Jerry said some peer municipalities have requested site visits but the site may not be fully suitable for tours until spring after startup and paving are completed. He invited council members to send questions to him by phone or email.

Why it matters: the rehabilitation upgrades clarifiers, headworks and odor-control systems and includes tertiary treatment required by future permit limits. The project’s cost, schedule and regulatory compliance will affect future operation and any decisions about capacity or additional construction.