Researchers at the Green Infrastructure Lab at Auburn University, Ala., are working on ways to reduce thermal pollution in stormwater by testing different types of pervious, impervious, shaded and porous cements.

The problem is that stormwater is currently reaching temperature levels that are too hot for aquatic life. Reaching temperatures of up to 122 degrees Fahrenheit, the stormwater runoff makes its way to larger bodies of water and unnaturally heats them, disrupting marine life.

Evidence suggests that this form of thermal pollution is happening in Mobile Bay, Ala., which is home to Alabama's seafood industry. The main stormwater outflow for downtown Mobile, Ala. flows directly into Mobile Bay and the water temperature of this stormwater has been recorded as high as 122 degrees Fahrenheit one July.

In order to find a solution to this problem, a test facility has been constructed at Auburn University. The goal of the research is "to evaluate the ability of multiple pavement types (impervious concrete, pervious concrete, pervious brick pavers), and rain gardens in mitigating thermal pollution in stormwater runoff."

Within the testing site are bins of different forms of concrete that are heated up by heating lamps (to simulate the sun) and an irrigation system. Each concrete bin is heated and then the sprinklers are turned on. Four thermometers are placed on/in each of the bins; one on top, one inside the concrete, one in the subgrade of the concrete and one in a catch basin below the bin. Temperatures are recorded and the data is collected, determining which form of concrete works the best in reducing thermal pollution.

The team hopes that this research can "establish a baseline measurement of heat removal effectiveness of pervious paving and rain gardens when used alone or in combination."