Guidelines for Design
|Automotive repair facilities and paint shops, dealerships, gas
stations, equipment degreasing areas, parking structures/areas, and
other facilities generating wastewater with significant oil and grease
content are required to pretreat these wastes before discharging to the
city or storm drain systems. Pretreatment requires that a clarifier or
oil/water separator be installed and maintained on site.
Clarifiers or oil/water separators for commercial/ industrial processes
must be sized on a case-by- case analysis of wastewater
characteristics. Typically a minimum capacity of 750 gallons is
required for small gas stations, auto repairs, and light commercial
sites; 1500 gallon capacity for large-scale truck washing and steam
cleaning facilities. The ultimate discharge must be directed to the
sewer system. All units regardless of size shall be fitted with a
standard final-stage sample box and spill-absorbent pillows.
|Clarifiers or oil/water separators should be installed in all new and
rebuilt parking structures or parking areas of newly built facilities.
Oil/water separators installed for parking areas and garages will be
sized according to10-minute peak flow guidelines. Ultimate discharge
shall be to the city storm drain system.
In all cases a site plan and sizing proposal must be submitted to the
Industrial Waste Section for initial approval. Plumbing hook-ups must
be performed by state licensed plumbers under permit and inspection of
the Building and Safety Division.
Clarifiers and oil/water separators cannot be used for the disposal of
hazardous waste such as coolants, solvent, Freon, hydraulic fluids,
transformer oils, etc. (SMMC 5.20.040 and 5.20.050)
Both clarifiers and oil/water separators must be periodically pumped
and have maintenance contracts in order to keep discharges within
limits. City inspections will ensure compliance.
Last updated: Friday, 02/05/2010