Onsite Wastewater
Operation and Maintenance Requirements. New and replaced onsite systems for domestic wastewater
installed after the effective date of Subpart B shall be subject to the same requirements for operation and
maintenance as structural stormwater BMPs for stormwater, including, at a minimum, annual inspection
reports and a recorded operation and maintenance agreement, pursuant to §42-241 (Maintenance). 
Standards for Operation and Maintenance. Onsite systems for domestic wastewater covered by Subpart B
shall be operated and maintained so as to avoid adverse effects on surface water and groundwater,
including eutrophication of surface water and microbial or nitrate contamination of groundwater. Septic
tank residuals shall be pumped whenever necessary to assure the proper operation of the system to meet
these standards, and the septage shall be reused or disposed of in a manner that does not present significant
risks to human health, surface water or groundwater.