A new report recommends that states require standardized testing to safeguard against environmental contamination caused by a widely used method for rehabilitating aging drainage culverts. Culverts divert stormwater away from roadways and are frequently made of concrete or corrugated metal. These objects are generally out of sight, but across the United States culvert infrastructure is decaying, said Andrew Whelton, an assistant professor in Purdue's Division of Environmental and Ecological Engineering and Lyles School of Civil Engineering.