Stormwater runoff plant

OFFLINE TREATMENT OF STORMWATER RUNOFF

Material:
Offline treatment of stormwater runoff sized in accordance with Lombardy Regional Law n°62 of 27th May 1985 consisting of underground modular tanks in LLDPE produced by rotomoulding and PVC pipes. The plant includes a flow splitting chamber, a modular storage system/grit separator with automatic shut-off valve and timed submersible pump, a grit and an oil separation system with coalescing filter sized according to UNI-EN 858-1 and complying with the requirements of D.lgs 152/2006.

Use:
Treatment of stored stormwater runoff from impermeable areas with presence of mineral oils, hydrocarbons and heavy sediments coming from vehicules parks placed in industrial and residential areas as well as service stations.

Application:
the runoff water coming from impermeable transit areas flow to the treatment system, which is sized to treat the first 5 mm of rainfall. Once the storage tank has been filled, a shut-off valve activates the bypass which sends the secondary and not-polluting rainwater to the storage tank. The stored and polluted rainwater is evacuated by a submersible pump controlled by an electric panel that regulates the emptying of the storage tank in such a manner that 48/72 hours after the rainfall, the system is ready for a new operating cycle. This step is required in order to avoid overloading the urban drainage system and to ensure that only the rainwater producing a potentially polluted runoff flow is treated. The runoff water is consequently sent to the grit and oil separators. The last stage of the treatment is defined according to the discharge: a gravity oil separator is foreseen in case of a public sewer, while in case of a surface watercourse the treatment plant consists of a coalescing filter oil separator.

Installation: please strictly follow the “installation instructions” provided by Rototec.

INFINITANK TREATMENT OF STORED STORMWATER RUNOFF

Material:
Treatment of stored stormwater runoff sized in accordance with Lombardy Regional Law n°62 of 27th May 1985 consisting of underground modular tanks in LLDPE produced by rotomoulding and PVC pipes. The plant includes a flow splitting chamber, a modular storage system/grit separator with automatic shut-off valve and timed submersible pump, a grit and an oil separation system with coalescing filter sized according to UNI-EN 858-1 and complying with the requirements of D.lgs 152/2006.

Use:
Treatment of stored stormwater runoff from impermeable areas with presence of mineral oils, hydrocarbons and heavy sediments coming from vehicules parks placed in industrial and residential areas as well as service stations.

Application:
the runoff water coming from impermeable transit areas flow to the treatment system, which is sized to treat the first 5 mm of rainfall. Once the storage tank has been filled, a shut-off valve activates the bypass which sends the secondary and not-polluting rainwater to the storage tank. The stored and polluted rainwater is evacuated by a submersible pump controlled by an electric panel that regulates the emptying of the storage tank in such a manner that 48/72 hours after the rainfall, the system is ready for a new operating cycle. This step is required in order to avoid overloading the urban drainage system and to ensure that only the rainwater producing a potentially polluted runoff flow is treated. The runoff water is consequently sent to the grit and oil separators. The last stage of the treatment is defined according to the discharge: a gravity oil separator is foreseen in case of a public sewer, while in case of a surface watercourse the treatment plant consists of a coalescing filter oil separator.

Installation: please strictly follow the “installation instructions” provided by Rototec.

INFINITANK CONTINUOUS TREATMENT OF STORMWATER RUNOFF 

Material:
continuous  treatment  of  stormwater  runoff  consisting  of LLDPE modular tank, one-piece structure, with PVC inlet and outlet pipes and NBR rubber gaskets, including flow  splitting  chamber, grit  and  oil  separators  with  coalescing  filters sized according to UNI-EN858-1 and complying with requirements of Reg. Lombardia L.R. 27 maggio 1985 n. 62.

Application:
The  plant  allows  the  continuous  treatment  of  stormwater  runoff from  impermeable  surfaces  up  to  10000 m2  used  for  transit  or parking in industrial areas, residential zones and service stations subject  to  possible  pollution  from  mineral  oils,  hydrocarbons, sand/grit  and  inert  materials.  The  stormwater runoff  treatment system makes use of the action of a grit and oil separator in continuous operation capable of treating flows of up to 40 l/s. Runoff from impermeable transit areas must be carried to the treatment system. The treatment tanks receive the flow appartaining to first 5 mm of rain falling over a 15 minute period. For higher flows, the bypass is activated which sends the excess to the stormwater storage tanks. The treatment plant consists of a grit separator and an oil separator with coalescing filter, thus ensuring that the final effluent possesses the appropriate characteristics for discharge to a body of surface water.

Use and maintenance:
the grit, oils and other light liquids transported by stormwater runoff accumulate inside the tanks during the normal exercise of the plant. These accumulations become excessive over time and tend to affect the efficiency of the purification. For this reason, it is essential to carry out periodic inspections of the tanks and, if necessary, proceed with purging and cleaning. The frequency of such operations depends on the pollutant load of the effluent. As regards the coalescing filter, it is necessary to pull it out periodically and wash it with a strong jet of water. The purging must be carried out by competent and authorized companies as the effluent is considered hazardous waste and must be treated as such.

Installation:
please strictly follow the “installation instructions” provided by ROTOTEC.