Porous Asphalt for Better Water Management

Oconomowoc-based company, Wolf Paving Co. Inc. is making porous asphalt. This technology allows water to flow through the asphalt into a stone bed collection area under the parking lot.

“Eventually, the water will move down through the ground and replenish the groundwater,” said Sean Wolf, vice president of Wolf Paving Co. “Porous asphalt allows businesses to be more creative on how to deal with water, plus it’s good for the environment.”

While it initially costs more to install, there are savings overall, Wolf said. For example, some local governments charge developers stormwater impact fees when water runoff from paved areas overwhelms the storm sewer system. With porous asphalt, the demand on storm sewers is reduced so the impact fee can be eliminated. 

Developers also save money by not needing to install a retention pond or other stormwater management solution on-site. That land can instead be used for development.

Another benefit: No standing water – which is especially helpful in Wisconsin, where standing water can turn into ice.

For businesses that prefer concrete, Waukesha-based Spancrete Inc. developed RePlenish, a pervious precast concrete.

“The name says it all – it helps replenish the aquifer by allowing rainwater to flow through it to the groundwater below,” said Kimberly Wacker, vice president of marketing and communications for Spancrete.

Some businesses use a cistern-like system under RePlenish to use the collected liquid to water on-site landscaping or vegetation, Wacker said.

“The pervious precast concrete allows some businesses to increase their parking space or concrete area,” said Wacker, adding Milwaukee World Festival Inc. installed some of the material at Henry Maier Festival Park, allowing it to expand the area covered by concrete, since the water was easily collected and placed back in the groundwater, versus treated as wastewater as it entered the city sewer system.

Both pervious concrete and porous asphalt require one bit of extra maintenance – they need to be swept or vacuumed off a couple times a year or else the small holes can become clogged, Wolf said.

For dealing with the rain and snow that hit a building’s roof, adding a blue roof is another option for businesses to handle water. A blue roof – not a green roof featuring plants, which is another option for handling water – has a structure that collects rain and rather than release it immediately into the municipal stormwater system, waits an allotted amount of time – about 12 hours – before slowly letting it flow down the drain spouts.

Blue roofs are relatively new, with few in the area. Mortara Instrument Inc. included one when it built its 64,000-square-foot facility in Milwaukee last year, as did Dominion Properties in its Sage on Prospect apartment building at 1825 N. Prospect Ave., Milwaukee.    

For businesses using a lot of water, improved resource management can lower costs and help the company be a better corporate citizen.

Source: BizTime 
Video source: NCAT Auburn University