I have an existing fueling facility (single 1,000gal tank) that was retrofitted a while back with a spill containment system that consists of a series of strip drains and catch basins to retain any spill during fueling. The issue is that the containment system has no outlet and is open to rainfall which can result in it filling with stormwater during the wet period. Low evaporation rates and consistent rainfall have been shown to allow fuel spilled during filling or delivery to simply overflow at the downstream catch basin and sheet flow over the pavement to the stormwater system. The system was designed to DEQ SPCC standards and accounted for rainfall contribution to the system, but some events have pushed it over the edge. The site is also within 1500ft of the Pacific Ocean.

Would an oil-water separator allow us to connect to the stormwater system so we don't have to worry about pumping the catch basins every time they fill with water? The stormwater system eventually discharges to a low point at the site. I'm not familiar with the limitations of oil-water separators and if one would even be allowed in this type of installation or what type of permitting would be required. I've only seen them installed in parking lots, which do connect to downstream stormwater systems, but I wasn't sure if a fuel facility would be treated differently.