SD1 • 1045 Eaton Drive, Ft. Wright, KY 41017 • Ph 859-578-7450For more information or a tour of Public Service Park, call the storm water hotline at 859-578-6745.

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OverviewOil/water separators are structures designed to remove oil, grease, sediment, and floatable materials from storm water runoff through gravitational settling and trapping. These Best Management Practices(BMPs) are well suited for dense, urban areas, where they can be installed underground to treat runoff from parking lots and other vehicle use areas.

DescriptionOil/water separators, also called oil/grit or gravity separators, are BMPs that use gravity and settling to separate grit, sediment, and floatable materials like oil and grease from storm water.

The oil/water separator consists of chambers that are separated by baffles, one for sediment removal and the other for oil removal. The water flows into the first chamber, which is designed to allow solids to settle out of the water column and be stored at the bottom of the chamber. The water and oils then pass over the top of a baffle into the second chamber. Here, a vertical baffle extends down into the water column and allows the oil and grease to float to the top while the clean water flows out.

The oil/water separator is efficient in trapping pollutants, but these must be removed through regular maintenance to maintain effectiveness. Additionally, oil/water separators do not reduce the volume of storm water nor remove dissolved pollutants.

Oil/water separators can be cast in place or are available as prefabricated proprietary systems from a number of vendors.

Benefits• Improves water quality by removing sediment, grit, oil, grease, and

other floatables from storm water runoff• Easily accessed for maintenance• Underground installation for urban areas• Compatible with storm drain systems• Long life span with proper maintenance

Design & Siting Considerations• Oil/water separators are best for areas with high

vehicular traffic such as industrial, commercial, or ultra-urban settings. • Sizing of the oil/water separator will depend on the

size of the site, and contributing drainage area.• Contributing drainage area should not exceed one

acre of impervious area.

Maintenance• Clean out every one to six months.• Catch basin cleaning equipment should be used for

cleaning.

Cost ConsiderationsCosts vary tremendously based on the amount of con-tributing drainage area and the numerous proprietary vendors.

Links• SD1 BMP Manualhttp://www.sd1.org/resourcehandler.aspx?id=261

• Metropolitan Council, St. Paul, MNwww.metrocouncil.org/environment/Watershed/BMP/CH3_STDetOilGrit.pdf

• Georgia Stormwater Management Manual, Volume two: Technical manualwww.georgiastormwater.com/vol2/3-3-6.pdf

Public Service Park OIL/WATER SEPARATOR DetailsSD1’s oil/water separator is located in the rear of the building, collecting runoff from the materials storage area and parking surrounding the maintenance garage. It is installed under the pavement and connected to the catch basins in the parking lot. SD1’s unit is 60 feet long and 6 feet in diameter. It was donated to SD1 by Advance Drainage Systems (ADS) for demonstration purposes.

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P U B L I C S E R V I C E P A R KP U B L I C S E R V I C E P A R K

EATON DRIVE

BANKLICK CREEK

ADMINISTRATION BUILDING LAKEVIEW

PUMP

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LAKEVIEW

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Vegetated Roof

Underground Detention

Bio�ltration Swale

Permeable Pavers

Vegetated Swale

Wetland

Retention Pond

Permeable Concrete

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Outdoor Classroom

Storm Water Garden

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Urban Forest

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P U B L I C S E R V I C E P A R KP U B L I C S E R V I C E P A R K

EATON DRIVE

BANKLICK CREEK

ADMINISTRATION BUILDING LAKEVIEW

PUMP

STATION

GARAGE

LAKEVIEW

GARAGE

Vegetated Roof

Underground Detention

Bio�ltration Swale

Permeable Pavers

Vegetated Swale

Wetland

Retention Pond

Permeable Concrete

Permeable Asphalt

Outdoor Classroom

Storm Water Garden

Cistern

Runo� Surfaces

Oil/Water Separator

Detention Pond

Urban Forest

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Step Pools

Upper Trail

Lower Trail

Creek Overlooks

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2020

COLLECTION SYSTEMBARN

MATERIAL STORAGE AREA