Use
Rainwater runoff treatment system for outdoor yard sized
considering a rainfall of 400 l/s*ha suitable to convey rainwater
(5 mm in 15 minutes as per Regional Reg. Lombardy no. 4 of
24/03/06) in the storage area to then be degreased prior to the
delivery into the final receptor after a time of ..... h (between 1 and
100 hours) from the end of the rainfall. The final receptors may be
watercourses.
Operation
The rainwater containing oils, hydrocarbons, suspended solids
and sediment, enter the selection tank where coarse solids (gravel,
crushed rock) decant, thus ensuring the perfect functioning of
purification in later stages.
The wastewater, free of coarse solids, overflows into the
COVERED AND UNCOVERED PAVED AREAS
COMPLETE PLANT - DRAIN TO WATERCOURSES
Maintenance
To maintain the EPRAIN ACC F.C. rainwater runoff treatment system
efficient it is necessary to check the following every six months:
•
Check the presence of inert materials (gravel and sand) inside
the selection tank;
•
Check for the presence of the sand inside the storage tanks
checking that they do not obstruct the suction port of the pump;
•
Check the presence of inert materials and oils inside the grease
separator;
•
Check that there are no materials that could obstruct the
coalescing filter;
•
Verify the correct operation of the inlet valve on the first
installation;
•
Check the electrical connections.
Proceed to the drainage in the case of:
•
excessive presence of gravel and sand inside the selection tank.
•
a level of sand inside the accumulation installations blocking the
mouth of the electric pump.
•
excessive material (sands) inside the grease separator (about
40 cm of material deposited on the bottom).
In the event of excess oils within the grease separator, proceed to
their removal.
If the coalescing filter is particularly dirty, proceed to its removal,
cleaning and reinsertion.
Specification Item
Supply of rainwater treatment plant (5 mm) for paved surfaces of....
m
2
and suitable for the drain of treated water into surface bodies; this
system consists of the following artefacts:
sedimentation/accumulation sector sized to contain
rainwater (the first 5 mm of rainfall evenly distributed over
entire drainage area served by the drainage network as
Regional Decree of Lombardy no. 62 of 27/05/85). Once
sedimentation/accumulation sector is filled the return valve,
located upstream of the system, blocks the return of the water
stored, while the wastewater that continues to enter the selection
tank causes the raising of the door in the well so that the water
overflows into the bypass pipe flowing directly into the final
receptor.
The wastewater stored in the sedimentation/accumulation
sector, after being separated from the sedimentable substances
is re-launched to a coalescing oil separator using a submersible
impeller electric pump complete with safety float.
The discharge of the sedimentation/accumulation sector takes
place at a distance of 48 hours from the end of the rainfall through
•
the electric pump triggered by an electronic control unit actuated
by a rain sensor. The switching off is guaranteed using a minimum
float placed inside the sedimentation/accumulation sector.
•
In the oil separator with the coalescing filter, the physical separation
of oils and hydrocarbons by flotation and by coalescence will take
place.
t (0-100 hours);
The grease separator can be equipped with a floating obstructer,
•
which guarantees the outgoing flow interruption in case the
setting area of the grease separator has accumulated an excessive
amount of oil/hydrocarbons avoiding, therefore, the drain into the
•
final receptor. The rainwater, once treated, is passed through an
inspection well into the final receptor.
The system is equipped with a non-return valve that closes the
accumulation when full and an electric pump that after a certain
time t will send the water to a grease separator.
Grease separator where the physical separation of oils and
hydrocarbons by flotation and coalescence will take place (by
passing the wastewater through a polyurethane foam filter);
the
the
per
the
Flow splitting chamber suitable to send the rainwater to the
storage tank and send the waters from secondary rainfall,
through bypass piping directly to the receiving body of the water;
Storage tank suitable to accommodate a quantity of rain of
height h = 5 mm uniformly distributed throughout the square in
question; the water to be treated will be stored inside for a time
•
End of rainfall sensors operate the electric pump which will
empty the installations after a time t from the end of the weather
event;
•
An electrical system suitable for the management of the plant.
All the artefacts are made of constant thickness polyethylene (12
mm) with the rotational moulding technique and consist of ribs,
which confer resistance for underground use, complete with screw
caps for inspection and relative extensions.
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