Oil Water Separators
HydroTech Environmental supplies, installs and services oil water separators for wash water. The oily, gritty runoff from pressure washing, wash racks and vehicle wash bays. Our above-ground oil/water/solids separators, clarifier systems and portable Porta-Pad wash systems remove free oil and settleable solids so wash water can go to the sanitary sewer or on to a recycle system. Every system is sized to your flow rate and site, then installed and maintained by our team in Rohnert Park, serving Sonoma County and the North Bay since 1990.
How an Oil Water Separator Works
Oil is lighter than water, and an oil water separator puts that to work. Wash water enters the tank and slows down, giving free oil time to rise and heavier solids time to settle. Closely spaced plates gives small oil droplets a surface to collect on until they grow large enough to float. A skimmer or decanter draws the oil off the top for disposal, solids are cleaned out of the bottom, and the treated water flows out.
Our WOS and WCL systems also add corona-discharge ozone injection, commonly used to control odor and bacteria in stored/treated water.
One limit to know: a mechanical separator does not remove emulsified oil. Heavy degreasers and some detergents can emulsify oil so it stays mixed in the water. If that’s your wash stream, a reactant system may be needed alongside or instead of a separator.
Which Oil Water Separator Fits Your Operation?
| System | Best For | Flow Rate | Key Features |
|---|---|---|---|
| Above-Ground Water, Oil, Solids Separator (WOS Series) | Fixed wash racks and shops discharging to the sanitary sewer | 0-15 or 0-30 GPM | 3-stage stainless-steel tank with sloped bottom; 672 or 1152 sq. ft. coalescing media; 170- or 340-gallon capacity; oil skimmer/decanter; ozone |
| Clarifier and Oil/Water Separator (WCL Series) | High-solids wash water: mud, grit and sand from heavy equipment, construction and ag | 0-30 GPM | 600-gallon cone-shaped clarifier; bag-filter solids chamber; 73 or 425 sq. ft. coalescing area; oil skimmer; ozone |
| Porta-Pad & Water Oil Separator System | Sites without a permanent wash bay, or washing that moves between locations | Sized to the job | Patented 12′ x 22′ containment mat; submersible pump; drive-on ramps; water oil separator; one-person setup |
Where Oil Water Separators Are Used
Any operation that washes vehicles, equipment or parts produces water carrying oil, grease, fuel and grit. Common applications include:
- Fleet, transit and bush washes
- Rental car and equipment rental yards
- Auto and truck dealerships and service shops
- Construction, landscaping and heavy equipment washing
- Vineyard and agricultural equipment washing
- Municipal corporation yards and public works facilities
- Mobile pressure washing crews that need containment on site
Oil Water Separator vs. Wash Water Recycling System
An oil water separator cleans wash water so it can be discharged. A wash water recycling system treats it further so you can reuse it, cutting both fresh water use and sewer discharge.
The two often work together: the separator handles oil and solids first, and the recycling stage polishes the water for reuse. If you’re washing at high volume, paying sewer fees on discharge, or can’t connect to the sewer at all, a recycle or biological treatment system is worth pricing alongside a separator. A properly designed pit system under the wash area helps either setup run reliably.
Oil Water Separator Installation & Service in Sonoma County
HydroTech has designed, installed and serviced wash water treatment equipment from our shop in Rohnert Park since 1990. We work directly with engineers, contractors and regulatory agencies to get the system specified correctly, handle installation and training, and back it with service contracts so your separator keeps performing.
We provide on-site service within 40 miles of our shop, covering Santa Rosa, Petaluma, Rohnert Park, Windsor, Sebastopol, Healdsburg, Sonoma, Napa, Novato and the rest of the North Bay.