Knox County, TN Environmental Rules: Erosion Control (2026)

Sec. 26-251, part of the county's Division 5 erosion prevention and sediment control rules, requires "adequate erosion prevention and sediment control measures" on all land-disturbing activities, including projects exempted from filing a full stormwater management plan under Sec. 26-171, specifically to keep sediment from leaving the site or reaching state waters. Operators failing to install controls and causing off-site sedimentation are subject to enforcement. Sec. 26-252 spells out how: design, installation, maintenance and inspection must follow the State of Tennessee NPDES General Permit for construction stormwater, the TDEC erosion and sediment control handbook, and the county's own stormwater management manual, and wherever these conflict, the stricter standard controls.

Sites discharging into impaired or exceptional Tennessee waters, and "priority construction activities," face additional requirements, and the director can demand more stringent controls where a threatened or endangered species' habitat is at risk. Sediment basin and trap discharges must run through a pipe or a rip-rap-lined spillway so they do not cause erosion, and sediment-laden water pumped from excavations must be held in a settling basin or filtered before release, discharged only onto a stabilized outlet point. Construction site operators must also control other construction wastes, such as discarded building material, concrete truck washout and sanitary waste, that could harm water quality.

The erosion-control portion of a project's performance bond is released only after the site reaches final stabilization under the state general permit, and the director can hold it longer or demand extra measures on a priority site or one with a history of off-site sediment damage.