“Grasspave2 was perfect for what we needed, especially in the sandy soil, “ says Ryan Damery, an aviation engineer and project manager for HNTB. According to Damery, the Grasspave2 sits on 12 inches of PMB material. Additionally, 18 inches of soil were removed outside of the units to provide sand filtration for the runoff, enough to filter out bacteria from the stormwater before it infiltrates into an underground storage unit or reaches ground water supplies.
For runoff that will exceed the infiltration rates that the existing soil conditions can handle, HNTB deigned a cyclonic filter to treat the water before it reaches the city storm drain. These devices will collect debris, pollutants, sediment, oils and grease. The cyclonic filters are primarily used in the east side of the airport where the clay soil conditions would not allow high enough infiltration rates to satisfy SUSMP requirements with the infiltration swale alone.
Porous pavers, such as Grasspave2, provide a drivable surface suitable for H-20 rated maintenance roads, and also allow rainwater to flow into the ground instead of sheet flowing off site carrying pollutants to fresh water supplies.
reader service no. 144
