Oshkosh staff outline schedule for major water and wastewater projects, highlight chlorine risk removal

City staff briefed the Oshkosh City Council at a workshop Oct. 15 on the status and timing of major water and wastewater capital projects, saying the Clearwell project and a tertiary filtration and phosphorus-treatment upgrade are moving toward bids next winter and that the wastewater plant will include ultraviolet (UV) disinfection to replace gaseous chlorine.

The projects are part of the 2026 Capital Improvement Program (CIP) and remain in design or late-design phases, staff said. The Clearwell project—staff said the item has been in the CIP for several years and preliminary engineering began five to six years ago—was authorized for construction by the Public Service Commission in June, and staff expect to advertise the work for bids in November with a council award in January. The tertiary filtration and phosphorus project is between roughly 60%–90% design; staff said it is scheduled for bids in February 2026 and a council award in March 2026. The UV disinfection work will be combined with the tertiary filtration project to replace gaseous chlorine disinfection at the wastewater plant.

City staff described the chlorine hazard at the plant as significant: the existing gaseous-chlorine risk extends roughly a 1.3‑mile radius that includes parts of downtown Oshkosh, Lourdes, Oshkosh West and the University of Wisconsin–Oshkosh campus. Staff said replacing gaseous chlorine with UV disinfection will remove that community risk and reduce the need for several other chlorine-related projects previously planned in later CIP years.

Staff also described several related infrastructure items: a new, automated water‑meter test bench to meet Public Service Commission testing requirements (design underway); pump-station work, including the Washburn Booster Pump Station that serves elevated areas west of I‑41 and south of 20th Avenue; and collection‑system inspections for large-diameter river crossing interceptors, which require specialized inspection technology because high flows prevent simple bypass operations.

On intake and supply resiliency, staff reported two winters in which frazil ice partially or fully blocked the primary lake intake; those events required prolonged pumping and near-activation of fire-department dive operations. Because the lake depth and intake geometry make frazil formation possible, staff said design work will begin on backup intake options and on modifications to the primary intake to reduce the likelihood of future blockages.

City staff also noted generator upgrades tied to the filtration and UV projects because the added electrical load will require expanded standby power capacity.

Quotes in the meeting were from staff: “We did finally get that authorization, the June year…we are going to have that out on the street for bids in November with a bid award coming to council in January,” and “If you’re going to think about doing this, the best time to do it is with this tertiary filtration project,” (both staff member James, utility services). On public-safety benefits, staff said a member of the fire department hazardous‑materials team reacted positively to removing the chlorine risk.

Ending: Staff presented schedules and design progress but noted several items remain contingent on final design, procurement schedules and future council approvals. Councilmembers asked for further detail on rate impacts of utility projects before final budget approval; staff said they will provide rate‑impact estimates for the full set of utility projects at a later meeting to allow council review before rate decisions.