The Philadelphia Water Department (PWD) is using a major employee parking lot as a testing ground for various types of permeable pavement materials designed to prevent stormwater runoff from polluting local rivers and streams. Funded by the PWD and the Environmental Protection Agency, the project will test and showcase up to six different types of permeable pavement.

Construction of the permeable parking lot is already underway at the Southwest Water Pollution Control Plant and is expected to conclude next spring. Because permeable pavement has the potential for widespread use throughout Philadelphia, the employee parking lot will include multiple forms of pervious concrete, porous asphalt and permeable paver products. Additional upgrades to the site will include new landscaping and demonstrable stormwater management techniques.

The success of each material will be monitored closely for factors such as cost of installation, stability of the systems, permeability over time, maintenance requirements, and the ability to replicate it elsewhere. A review of how each type of material performs and reacts under the same conditions will allow PWD to determine its role for future projects around the city. The parking lot initiative is one of three PWD green infrastructure projects that will receive a total of $1.14 million in EPA funds.