MoDOT Minimizes Construction's Impact on Environment

The Missouri Department of Transportation, like many government entities and private contractors, makes an effort to reduce the impact of construction on the environment. A recent example to MoDOT's green commitment is its work on the Route 141 reconstruction project in west St. Louis County. The Route 141 project includes relocating a section of the road slightly east of its current location. It also calls for raising the roadway out of the floodplain, according to MoDOT. “As we were evaluating and designing the Route 141 project, one of the biggest concerns the public presented to us was preserving the environment,” said Karen Yeomans, MoDOT area engineer for west St. Louis County. The design team evaluated the entire construction area and established protection zones to reduce the number of trees being removed for the project. The construction contractor who removed or damaged trees in the protection zones would be penalized. “We also made sure, though, that we wouldn’t have trees too close to the road that could fall and endanger drivers,” Yeomans said. The construction contractor also got involved by incorporating an idling policy that prohibited construction vehicles from idling for extended periods of time. Additional environmentally friendly elements of the project include using wicking drains 0 which absorb ground water and bring it to the surface naturally - instead of pumps to help remove water from the ground. A lot of the material for the project is reused or recycled as well. The trees that were removed were made into mulch and used for erosion control. Concrete from Olive Boulevard and Ladue Road will be used for the new roadway base or for fill. In addition, MoDOT is also testing new environmentally friendly technologies. The department tested the "two lift paving" process to place concrete, which lays down a thick layer of concrete and then immediately places a second, thinner lift, or layer, of concrete on top of that thick layer. Concrete placed using this method is as strong as that used on standard concrete pours, MoDOT says. “What this process allows us to do is place two different concrete mixtures. On the Route 141 project, this will be used to test a special concrete additive that captures pollutants and breaks them down using sunlight,” said Yeomans. MoDOT will test a 2,000-foot section of the new Route 141 with this smog-eating concrete. Learn more about the Route 141 project and check for updates on the MoDOT website.