Midway officials warn sewer plant near capacity; ground-level audit could lead to development moratorium

Midway city leaders said the town’s sewer treatment plant cannot be expanded further under current conditions and that the city will deliver a ground‑level audit to the county in a few months to clarify remaining capacity.

That audit will inform whether the county — which controls the special service district that governs sewage service — should impose limits on acceptance of new development. “We let the county know we can't have anything else, that we are doing a ground level audit. We'll be ready in a couple months. We'll go back to the county with more information,” Mayor said during the March strategy meeting.

Why it matters: Municipal development approvals often assume sewer capacity is available. If the audit confirms capacity limits, the county (which controls the Heber Valley Special Service District) could adopt a moratorium or other restrictions that would directly affect pending subdivisions and building permits in Midway and nearby communities.

City officials described the technical and governance issues that complicate capacity accounting. Midway said the plant currently processes about 2,500,000 gallons per day and was designed to handle about 4.5 million gallons per day, but prior planning used “ERUs” (equivalent residential units) rather than measured flows; officials do not yet know how ERUs translate to actual flow in every case. “When we approve a new development … that's a minuscule amount almost. But that's the only thing we're trying to determine. We do everything based on ERUs, and we don't know how the ERUs really translate in terms of flow,” the Mayor said.

Officials also described cross‑jurisdictional wheeling agreements that have shifted demand. Some developments were allowed to “wheel” sewage through Heber to the HVSSD plant under loose arrangements, which blurred accounting and left Midway uncertain how much capacity remains for its own growth. The council recounted that Heber and other jurisdictions have made informal arrangements in the past that now complicate dividing remaining capacity among Midway, Heber and Charleston.

The city discussed alternatives and limits of local authority. Midway’s advisory sewer board cannot deny service; that authority rests with the county. The city can ask the county to act, or it could seek a temporary development moratorium if county action is not forthcoming. The Mayor noted alternatives such as on‑site septic systems and “alternative systems” approved by the health department, but cautioned those would require local code changes to prohibit them: “So we could end up with a bunch of alternative systems … We would have to change our code to say we wouldn't accept that.”

Officials also outlined disposal constraints. Unlike nearby systems with broader effluent options, Midway relies mainly on rapid infiltration basins and a farm; the city said it has no feasible option to discharge effluent to the Provo River, limiting opportunities to expand treatment capacity.

What comes next: City staff will complete the ground‑level audit and return to the county and the council with specific flow data and recommendations in a few months. Council members repeatedly said they will press the county and the special service district to develop clearer allocation rules so Midway can make informed land‑use decisions.

Speakers quoted in this article appear in the meeting record and are listed in the speaker section below.