Did you know that storm water runoff is a leading source of pollution in waterways? Pervious concrete is structurally quite similar to conventional concrete as it is made from a mixture of cement, coarse aggregates, and water, but it doesn’t contain much sand, leading to a porous open cell structure that water passes through easily. When used for paving, pervious concrete stores rainwater at 3-5 gallons per minute per square foot of surface area, which can be stored in a coarse gravel layer underneath the pavement or allowed to percolate into the underlying soil, leading to natural water filtration. The pavement itself acts as a retention area; it helps prevent polluted runoff that normally occurs with impervious pavements. The U.S Environmental Protection Agency is looking at pervious concrete as a viable solution to the fact that 90% of surface pollutants are carried by rainfall.