Sewer capacity shortfall: BOMA weighs on‑site treatment, I&I work and a temporary pump‑and‑haul for builders

Spring Hill staff warned the Board of Mayor and Aldermen on Oct. 20 that the city’s water reclamation facility currently reports a rolling 12‑month average flow of 4,230,000 gallons per day (4.23 MGD). With the Tennessee Department of Environment and Conservation reporting threshold at 5,000,000 gpd, staff said the city has roughly 800,000 gpd of remaining capacity but recommended maintaining an internal buffer and not allocating fully to the 5.0‑MGD cap.

Staff presentation and six buckets

City staff described six categories of vested commitments and estimated gallons per day associated with each: building permits already issued (approx. 357,000 gpd), grading permits (approx. 165,500 gpd), project sewer reservations tied to approved ordinances (Legacy Point, Spring Hill Commerce Center — combined estimates nearly 294,000 gpd after adjusting for units already vertical), critical infrastructure (hospital, public works — about 63,000 gpd), projects with engineering approval but no grading permit (approx. 172,000 gpd), and requested construction approvals (nearly 500,000 gpd). When combined with current flows, staff…