Improving the Cost Effectiveness of Highway Construction Site Erosion and Pollution Control

摘要

A comprehensive two-phase effort was conducted to improve the cost-effectiveness of erosion and pollution control at highway construction sites. The initial work included laboratory model-scale testing of sedimentation pond designs and field monitoring of ponds to establish their effectiveness in pollutant removal. A sedimentation pond was designed according to the laboratory findings, constructed in a highway right-of-way, and monitored for pollution control performance. Another sedimentation pond without these design features was tested for comparison. Monitoring consisted of flow measurement and water runoff composite sampling at pond inlets and outlets. Samples were analyzed for solids, metals, phosphorus, and organic content. Results demonstrated that the ponds designed according to the laboratory findings were both more efficient in pollutant removals and less costly (per unit area served) than the pond to which they were compared. The later phase of the work concentrated most on testing the ability of various mulches, blankets, and chemical products to prevent erosion on test slopes, as well as on the ability of silt fencing to contain erosion from such slopes. Overall, wood fiber mulch accompanied by grass seeding was the most cost-effective slope covering. The report is issued in conjunction with an erosion and pollution control manual, which is designed to implement the findings in highway construction practice.