An official website of the United States government. Here's how you knowHere's how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Latest Earthquake | Chat Share
Permeable pavement is a porous urban surface which catches precipitation and surface runoff, storing it in the reservoir while slowly allowing it to infiltrate into the soil below. This study will evaluate how well different types of permeable pavement reduces the amount of pollutants and runoff volume.
Urbanization of the landscape has an appreciable negative impact on the quantity and quality of runoff water entering our lakes and streams (Davis, 2005; Wang and others, 2001; Williamson, 1993). By replacing natural land covers (like grasslands and forests) with impervious surfaces (like parking lots and streets), we lose the water retaining role of the soil and vegetation. Increased runoff from impervious surfaces causes dangerous floods, severe erosion damage to our stream channels, diminished recharge of groundwater, and degraded habitat for our fisheries. These same impervious surfaces can transport the many pollutants deposited in urban areas, such as nutrients, sediment, bacteria, pesticides, and chloride. In the worst cases, the amount of pollutants in urban runoff are high enough to prevent us from being able to swim or fish in our local waters.
Efforts to reduce the impacts of urban runoff have been happening for some time at federal, state, and local levels. The Clean Water Act (CWA) is the primary federal law that regulates the quality of the nation’s water bodies. The CWA, through the National Pollutant Discharge Elimination System (NPDES) program, establishes pollution limits for anyone discharging into streams and lakes, including cities. In Wisconsin, NPDES permits are issued by the Wisconsin Department of Natural Resources (WDNR) which identify performance standards and limits for things like peak flow, runoff volume, phosphorus, and total suspended solids. As part of their permit, each city must prepare a management plan to meet these prescribed limits by implementing best management practices (BMPs). BMPs are practices, treatments, and technologies that can alleviate one or more if these negative effects. Permeable pavement is one of these BMPs that is believed to improve water quality and reduce the impacts of urban runoff.
What is Permeable Pavement?Permeable pavement is a porous urban surface composed of open pore pavers, concrete, or asphalt with an underlying stone reservoir. Permeable pavement catches precipitation and surface runoff, storing it in the reservoir while slowly allowing it to infiltrate into the soil below or discharge via a drain tile. The most common uses of permeable pavement are parking lots, low-traffic roads, sidewalks, and driveways.
What are the Potential Benefits of Permeable Pavement?General hydrologic benefits
Concerns People Have About Using Permeable PavementHere are some of the concerns and questions about permeable pavement:
Durability – Will permeable pavement last as long as traditional pavement?
Upkeep and maintenance – Permeable pavement can clog with sediment and pollutants, reducing its permeability and beneficial productivity.
Water quality – How much pollutant reduction can be expected? Of particular interest, low reductions have been observed for nutrients (phosphorus and nitrogen). This concern has two implications:
Temperature – What temperature reductions can be expected with permeable pavement?
Residence time – How long does the runoff need to stay in the storage layer to adequately treat the runoff?
Model accuracy – How well can existing urban runoff models predict the water quality benefits of permeable pavement?
Purpose of this study
We hope to determine the levels of volume and pollutant reduction achieved by permeable pavement by testing three different types of pavement (fig. 2). The following are the specific objectives:
A small portion of green space, adjacent to the overflow parking lot serving the Madison Streets Division’s East Office, in Madison, Wis., has been designated as the study location (fig. 3 and 4). The white study area shown in figure 4 is split equally into three smaller study plots, each receiving similar volumes of runoff from the adjacent parking lot. These plots will test three types of pavement: permeable pavers, permeable concrete, and permeable asphalt (fig. 5). Each plot is equipped with instrumentation to measure reductions in runoff volume (water quantity) and pollutants (water quality).
Measuring Water Quantity
Runoff from the parking lot flows toward an existing curb cut, which is equipped with a calibrated flume. Runoff enters the flume and drains into a concrete structure that divides the runoff into three equal portions, each draining to one of the three test plots (fig. 5). The runoff either infiltrates into the permeable subsurface or exits the plot as overflow runoff. Each test plot is lined with an impermeable membrane, which captures and routes infiltrated runoff through a buried drain tile (fig. 6). Runoff that does not infiltrate into the permeable surface is captured by an overflow surface grate. The test plots are constructed to prevent cross-contamination from adjacent test plots and surrounding soils.
Both the drain tile and surface grate are routed into a monitoring facility, where the volume of infiltrated and overflow runoff is captured separately (fig. 7). The monitoring facility accurately measures all inputs and outputs of water using calibrated flumes.
Measuring Water Quality
Water-quality samples will be collected from seven locations:
Water-quality samples will be tested at the Wisconsin State Lab of Hygiene, a certified USGS analytical laboratory. Samples will be tested for concentrations of the following pollutants:
Ancillary data will also be collected, including, but not limited to: precipitation, sand/salt application during winter months, runoff temperature at depth, and a record of maintenance.
This permeable pavement test site will be operated and maintained through 2018.
Davis, A.P., 2005, Green engineering principles promote low-impact development: Environmental Science and Technology, A-pages, v. 39, no. 16, p. 338A–344A.
Houle, K., Roseen, R., Ballestero, T., Briggs, J., and Houle, J., 2009, Examinations of Pervious Concrete and Porous Asphalt Pavements Performance for Stormwater Management in Northern Climates: World Environmental and Water Resources Congress 2009: p. 1–18.
Roseen, R., Ballestero, T., Houle, J., Briggs, J., and Houle, K., 2012, Water Quality and Hydrologic Performance of a Porous Asphalt Pavement as a Storm-Water Treatment Strategy in a Cold Climate: Journal of Environmental Engineering, vol. 138, no. 1, p. 81–89.
Wang, L., Lyons, J., Kanehl, P., and Bannerman, R., 2001, Impacts of urbanization on stream habitat and fish across multiple spatial scales: Environmental Management, v. 28, no. 2, p. 255–266.
Williamson, R. B., 1993, Urban runoff data book: a manual for the preliminary evaluation of urban stormwater impacts on water quality. Water Quality Centre, Ecosystems Division, National Institute of Water and Atmospheric Research
Below are publications associated with this project.
Below are partners associated with this project.