Council asks staff to draft standards to allow low-pressure sewer systems in source-protection area

Nate Reeves, a consultant who presented design options to the Wellsville City Council on Feb. 5, described low-pressure sewer systems — small grinder pumps on private lots that pump effluent through small-diameter pressurized mains — as an alternative to deep gravity sewers in the city————————————source-protection zone. Council members asked staff to draft a resolution adding the systems to the city's public works design standards and continued the item until the draft returns for review.

Reeves told the council the pump chamber sits on the homeowner's property and contains about a 60-gallon reserve; there is no long-term holding tank at each lot. "So there is not a holding tank associated with these," he said, describing a unit that grinds solids and pumps effluent into a small-diameter pressure main. He said jurisdictions that use this style of system have not had to replace pumps in 20'22 years of installations he reviewed.

Why it matters: the low-pressure approach reduces the need to trench 12'20 feet to chase gravity grades, lets pipe follow topography and uses smaller-diameter mains that, Reeves said, are self-scouring because pumps periodically flush the line. That could reduce heavy-equipment maintenance such as vac trucks and large lift stations, but it also shifts some equipment to homeowners (their grinder pumps) and requires new maintenance roles for the city on shared conveyance or community drain fields.

Details of the presentation and council discussion: Reeves said a single pressure main can serve up to about 50 homes at 3'4-inch pipe sizes and that manholes/cleanouts and flushing stations are spaced differently from gravity systems. He explained check valves at each pump prevent backflow into neighbors' homes and said the systems typically run at about 20'30 psi; larger regional lift stations operate at much higher pressures. When asked about power outages, Reeves said owners with backup generators commonly route the generator to the pump; otherwise residents would need to limit water use during an outage because the pump chamber holds only minutes of effluent.

City staff and consultants discussed limits and trade-offs. A city reviewer who said he's used the systems called them a "known solution" but warned they are "not foolproof" and will require occasional maintenance and cleanouts. Staff clarified that while homeowners would own and maintain on-lot pumps, the city would likely be responsible for the shared conveyance and any community drain field in the RPC/source-protection context. Reeves and staff also said if the receiving disposal exceeds 5,000 gallons per day the project would fall under state/Bear River Health Department jurisdiction for drain-field approvals; Reeves named Robert Beers at the state as an approver he has worked with.

The council and staff discussed alternatives and constraints. Reeves said some pump systems (he cited "Prelos" in the discussion) use on-site septic holding tanks which the city's source-protection code prohibits inside the source protection zone; that was one reason staff favored the grinder-pump model that avoids on-lot holding tanks.

Outcome and next steps: the council voted to continue the discussion so staff (Jay, the city attorney) can draft a resolution and update the design standards. Staff said the draft could return to the next council meeting after the planning commission public hearing cycle (roughly a month if the commission notices a two-week cycle). Council members said they expect to limit allowance to certain situations rather than permitting the technology everywhere.

Ending: Staff will prepare a draft resolution and updated public-works specification language and return it to the council (and then to planning commission) for public hearing and final action.