Permapave Stormwater Filtration Grates are specifically engineered to filter pollutants from stormwater before it enters the collection system. Permapave Stormwater Filtration grates may be installed into any existing inground or Side Entry storm water inlet.
Permapave grates filter 100% of gross pollutants from stormwater runoff. Gross pollutants are left on the surface, where they are easily collected and disposed of to appropriate sites. Some suspended solids remain trapped within the homogenous mass, and are removed during periodical cleaning.
Permapave Stormwater Filtration Grates can be manufactured to fit any size opening. Typically Grates are between 100mm and 150mm deep unless otherwise specified. Stone infill must be of sufficient strength to comply as roadbase. Some colorful stone may not be suitable to use as infill.
Permapave Stormwater Filtration grates comply with Australia Standard AS 3992 – 1992 and may be manufactured to A class, B class, C class and D Class. Grates to take greater loadings may also be manufactured.
Typically, Permapave Stormwater Filtration grates with 14mm – 20mm infill stone will capture 57 litres per second per square metre of grate surface. Capture rates may be increased if necessary by adjusting stone size and shape. Normal road inclines do not significantly effect capture rates.
Frequency of cleaning will depend on the frequency of rainfall events, the contaminant profile of a location and the pavement capture area of each grate. For example, grates installed near the beach may require greater frequency of cleaning than an inner city installation. Depending on those factors, grates may require cleaning each 10 – 12 weeks. Grates are easily cleaned and maximum porosity restored by mechanical vacuum. Contaminants removed during this process are captured for disposal to an approved site.