Clarifiers
& Oil/Water Separators
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.
Cautions
- 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.
