The precipitation water from the area to be drained is discharged at the lower end of the precipitation water treatment plant. The water is deflected tangentially by the deflection aid.
Here, sedimentation of particles, especially the sand fraction, takes place in a hydrodynamic separator due to turbulent secondary flows in a radial laminar flow regime.
These are collected via an opening in the lower part of the cleaning shaft in a sludge trap below the system. The sludge trap is sucked out at intervals.
Six filter elements are located in the center of the cleaning shaft. These are used to filter the fines in an upflow process, and a large proportion of the dissolved pollutants are adsorptively bound. The filter can be backwashed from the top and can be easily replaced in case of complete colmation.
The filter elements are easily removed through the existing manhole opening.
Above the stormwater treatment system, the clean water passes through an oil separator and then flows down the drain to infiltration or a surface water body.
The precipitation water treatment plant of the Hydrosystem 1500 type is installed in a plastic or concrete manhole with an internal diameter of 1.5 m at the factory.
A hydrodynamic separator causes the sedimentation of solids in a radial flow regime characterized by secondary flows. The action of the separator causes the solids to enter the flow-calmed sludge trap located below the separator hopper. Above the separator chamber are the six filter elements. The water passes through the filter elements in an upflow process. The system removes pollutants such as heavy metals, petroleum hydrocarbons and polycyclic aromatic hydrocarbons from the stormwater. It also binds nutrients such as phosphates. The quality of the treated water is so high that it can be discharged directly into groundwater or a surface water body. The difference in height between the inlet and outlet of this stormwater treatment system is only 25 cm, just like its little brother, the Hydrosystem 1500.
Since the stormwater treatment system is installed under the traffic surface, it does not require any additional space on the property or in the road space.
The stormwater treatment system can be used for traffic areas such as parking lots and roads of all traffic loads, industrial areas and metal roofs. The drain is equipped with a dip tube for light material retention. The sludge trap can be exhausted through the central maintenance pipe.
Stormwater treatment plant Technical data
Inner diameter of the concrete, plastic or fiber manhole: 1,5 m
Minimum height loss between inlet and outlet: 25 cm
Connectable area: 1,600 m² to 3,200 m² depending on the pollution and the cleaning objective
Maximum flow rate: Q = 105 l/s
Maximum filtration capacity: Q = 24 l/s
NJDEP Certified Test Results
Tested Model = 1500mm diameter with 4 filter cartridges
TSS Removal Rate of 80%
Particle size range 1-1,000 microns, D50=48 microns
Maximum Treatment Flow Rate (MTFR) = 53.6 gpm
Scour Test Flow Rate (≤20 mg/L) = 110 gpm
Sediment Loading per cartridge = 117.6 lbs
Maximum allowable drainage area = 0.2 acres (Based on an annual sediment load of 600 lbs per acre)