Oil-Water Separator Service

An oil-water separator is essentially a multi-chamber tank engineered around the density difference between water and petroleum products. Wastewater enters the inlet chamber, where heavier solids (grit, sediment, sludge) drop out. The flow then passes into a separation chamber sized to slow the water enough that suspended oil droplets can rise and coalesce — often helped along by coalescing media (corrugated plates or media packs that give the oil droplets surfaces to stick to and merge). Oil accumulates in an oil reservoir at the top; clean(er) water discharges from an outlet chamber to the sewer.

Facilities required to have one typically include auto dealerships with service departments, auto and heavy truck repair shops, commercial car washes (especially those that clean undercarriages), transportation fueling facilities and truck stops, fleet maintenance yards, vehicle auction yards, salvage and tow yards, scrap metal processors, and industrial maintenance operations where machinery is washed or oily process water is generated. Most are required by the local sewer authority's industrial discharge permit. The permit conditions usually dictate how often the separator must be serviced and inspected, with documentation kept on file for the permit reviewer.

The industry-standard service cadence is **quarterly oil-only pumpouts** plus **one annual full cleaning** per year. The quarterly visits skim the accumulated free oil off the top of the separator (and any easily-accessible sludge in the sediment chamber), keeping the unit's capacity from filling and reducing the risk of oil bypass into the sewer between annual cleanings. The annual visit empties the entire unit, washes the chambers, inspects baffles and coalescing media for damage or fouling, replaces media if needed, and verifies the unit is functioning as designed before refilling with clean water.

Facilities with higher oil-generation rates (busy car washes, heavy-truck repair shops, high-volume fueling) often need more frequent service than the quarterly/annual baseline. Conversely, low-volume operations may only need the annual visit. The first inspection visit tells us which category your operation falls into — we'll measure free-oil thickness and sediment accumulation and recommend a cadence calibrated to your actual usage rather than a generic schedule.

Every service visit produces a documentation packet: vacuum truck weight ticket, inspection notes (oil and sediment levels, media condition, any visible damage), and a certificate of disposition for the recovered material. For accounts under a sewer discharge permit, that documentation goes straight into the file the permit reviewer asks for during inspections.

Most oil-water separator service companies are middlemen on the disposal side. They pump out the separator, load the recovered oil/water/sludge into a tanker, and haul it to a third-party disposal facility — often through another subcontractor. The customer ends up with a manifest crossing two or three vendors and a disposal cost the OWS contractor doesn't control.

Cowart owns the whole chain. The vacuum truck that empties your separator is a Cowart truck. The driver is a Cowart employee. The DOT authority on the trailer is Cowart's. The destination is our non-hazardous wastewater treatment plant in Carrollton, GA, where the recovered material is characterized, treated, and disposed under our own permits and manifests. For your sewer-permit file, that means a single contractor name on every disposition record — and predictable pricing because we're not passing through markup from third-party haulers or disposal facilities.

We've been doing this work since 1974. Same family ownership, same treatment plant location, same operating model. For OWS customers under sewer discharge permits — where the inspector wants to see consistent contractor records year over year — that continuity is part of the value.