How Is Stormwater Designed for Solid Waste Facility Sites?

The drainage design starts with the site map divided by use: every area is classified as clean or contact, and the grading enforces it. Clean areas get the standard stormwater design — inlets, piping, detention, and water-quality treatment sized for the jurisdiction's requirements. Contact areas — tipping floors and aprons, process pads, stockpiles, the maintenance yard, fueling — are graded inward to collection with berms and curbs at every boundary so clean runoff cannot run onto them and contact water cannot run off. The design checks the separation in the grading plan itself: if the contours do not show it, the separation does not exist.

Contact-water containment is sized for the design storm on the contact areas plus the daily generation — tanks with secondary containment or lined ponds with the freeboard the permit requires. Treatment follows the permit: sedimentation for the fines, oil-water separation at the fueling and maintenance areas, and whatever additional treatment the discharge limits demand; where no discharge is permitted, the design provides the storage and the loadout for hauling. The stormwater pollution prevention plan is built from the design — the controls, the inspection schedule, and the sampling points the permit requires. And the design proves the containment holds through the design storm, because the violation happens when the system overflows.

A solid waste site stays compliant when clean and contact water never meet. The grading plan is the compliance plan. • Site divided into clean and contact drainage areas with physical separation • Contact areas graded to contained collection with berms and curbs at boundaries • Containment sized for the design storm plus daily contact-water generation • Treatment or hauling designed to the discharge permit's limits • Pollution prevention plan with inspections and sampling built from the design