Volume 2-05, Chapter 3 - City of Wichita

Section 3.3.2 - Gravity (Oil-Water) Separator
3.3.2 Gravity (Oil-Water) Separator Secondary Water Quality Facility
Description: Hydrodynamic separation device
designed to remove settleable solids, oil and grease,
debris, and floatables from stormwater runoff through
gravitational settling and trapping of pollutants.
KEY CONSIDERATIONS
DESIGN CRITERIA:
• Intended for hotspot, space-limited, or pretreatment
applications
• Intended for the removal of settleable solids (grit and
sediment) and floatable matter, including oil and grease
• Performance dependent on design and frequency of
inspection and cleanout of unit
STORMWATER MANAGEMENT
SUITABILITY
Water Quality Protection
Channel Protection
On-Site Flood Control
Downstream Flood Control
DISADVANTAGES / LIMITATIONS:
• Usually cannot alone achieve the 80% TSS removal
target
• Limited performance data
• Dissolved pollutants are not effectively removed
MAINTENANCE REQUIREMENTS:
• Frequent maintenance required
IMPLEMENTATION CONSIDERATIONS
L Land Requirements
H Relative Capital Costs
H Maintenance Burden
Varies
Varies
No Data
No Data
POLLUTANT REMOVAL
Total Suspended Solids
Nutrients – Total Phosphorus & Total Nitrogen
Metals – Cadmium, Copper, Lead & Zinc
Pathogens – Coliform, Streptococci & E. Coli
Residential Subdivision Use: No
High Density/Ultra-Urban: Yes
Drainage Area: 1 acres max.
Soils: No restrictions
Other Considerations:
• Hotspot areas
• Pretreatment
L=Low M=Moderate H=High
Volume 2, Technical Guidance Page 3 - 151