For inspection purposes only. Consent of copyright owner required ...

OIL INTERCEPTORS
Example of an Oil Interceptor
DESCRIPTION
il interceptors generally
comprise three underground
Oretention chambers designed
to remove coarse sediments and retain
oils. The first chamber is used for
sedimentation and removal of large
debris. This chamber contains a
permanent pool of water and a well
screened orifice which allows regulated
flow into the second chamber. The
second chamber is used for oil retention
and also contains a permanent pool of
water. An inverted elbow pipe permits
regulated flow from this chamber into
the third chamber. The inverted pipe
collects water from deep in the
permanent pool leaving oil
contaminants floating on the surface
until it is removed or absorbed by
sediment particles when they settle.
The third chamber is used to collect and
disperse flow into the stormwater drain
network or an infiltration basin. This
chamber contains an orifice outlet
which is often raised to create a third
settling pool and regulate outflow.
Inflow
Inlet
Accumulated
Coarse Sediments
TRIPLE INTERCEPTOR DEVICE
Construction Cost
L and Take
PRIMARY CONSIDERATIONS
Maintenance Requirements
MEDIUM
HIGH
LOW
DESIGN
1) Run-off segregation:
Only run-off from areas which are likely
to have oil contamination (e.g. filling
areas for service stations) should be
directed to the separator. This will
reduce the size of the separator
required. Appropriate use of bunding
may help segregate oil contamination
from 'clean' run-off.
2) High flow bypass:
The separator should be designed to
accept low flow only, with a high flow
bypass installed to provide for the
residual flow up to the capacity of the
pipe system.
Litter Screen
Over Opening
For inspection purposes only.
Consent of copyright owner required for any other use.
Inspection Hatch
Baffle Oil Elbow Pipe
BENEFITS
�Water
Quality Control YES
�Water
Quantity Control YES
�Amenity
Value NO
�Habitat
Creation Value NO
�Biological
Treatment NO
3) Interceptor chamber screening:
Ensure that the orifice between the
primary and secondary chambers is
effectively screened. This should
generally not allow debris greater than
5 millimetres in diameter to enter the
second chamber. It should be easily
accessible and easily removed for
cleaning.
4) Maintenance access:
Easy access is required for inspection
and cleaning. Each chamber could
have its own inspection entrance, with
step rings leading to the bottom of the
chamber.
Outlet Pipe
S OURCE
CONTROL
MORE OVERLEAF - 1 of 2
GREATER DUBLIN STRATEGIC DRAINAGE STUDY - ENVIRONMENTAL MANAGEMENT POLICY
EPA Export 24-08-2012:23:55:53