How Rutherford County might count wastewater and soils when calculating subdivision density

Williamson County planning director Aaron Holmes told Rutherford County planners that when a conservation subdivision uses a nontraditional or 'step' wastewater system, the acreage dedicated to soils and wastewater infrastructure is removed from the parent parcel before calculating allowable density. "So if they have a 100 acres, for example, they have 10 acres of wastewater, they only get to develop 90 acres of that, and that's what we base the density off of," Holmes said.

Holmes also said that even when a subdivision pumps to a regional wastewater system, the subdivision must hold soils on the parent parcel in reserve to support the system if the regional connection fails or is unavailable. He referenced local examples (Pine Creek and the Cox Ladd regional system) and described the county practice of requiring reserve soils and documentation within the concept plan.