Category:806 Pollution, Erosion and Sediment Control

Providing for erosion prevention is a necessary part of many highway construction and maintenance activities. EPG 806, as well as EPG 611 Embankment Protection and EPG 750.6 Erosion Control and Energy Dissipation are concerned with methods and criteria for the control of erosion and sedimentation from sheet and gully erosion associated with building and maintaining a transportation system.

Provisions of the federal Clean Water Act and related state rules and regulations require storm water permits where construction activities disturb one acre or more over the life of a project as part of a common plan or sale. MoDOT has a general State Operating Permit, obtained from the Missouri Department of Natural Resources (DNR), which allows for land disturbance activities associated with highway, bridge and compensatory mitigation construction as well as maintenance activities related to the upkeep of these features. The permit stipulates that MoDOT will develop effective Storm Water Pollution Prevention Plans (SWPPP) and follow certain guidelines to install temporary and permanent erosion and sediment control measures.

Locally sponsored federal aid projects involving an acre or more of land disturbance will need to obtain their own permits and develop effective SWPPPs. In some instances cities, counties and other government entities may already possess their own State Operating Permit and, in that case, must comply with their own SWPPP.

There are instances where contractors are working off MoDOT right of way or easement and will have to obtain their own permits for work involving borrow, staging areas, and excess (waste) disposal areas, and in some instances when portable plants are used. (See Fig. 806.8.1 MoDOT/Contractor Responsibility for details about the permitting requirements of these scenarios.) Also, in a few rare cases, MoDOT may require contractors to obtain their own individual State Operating Permit for land disturbance activities even though the project is being constructed on MoDOT right of way. These unique situations will normally be Design/Build projects that are funded by MoDOT, but totally managed by the contractor.

MoDOT's contract plans shall include erosion and sediment control measures that are sufficient to protect rivers, streams, lakes, ponds, wetlands and private land adjacent to MoDOT right of way.

Temporary and permanent erosion and sediment control measures shall be included in design plans such that contractors can develop appropriate bids. Control of water pollution will be accomplished through the use of best management practices (BMPs) such as berms, slope drains, ditch checks, sediment basins, sediment traps, silt fences, seeding and mulching, and other erosion and sediment control devices or methods.

Temporary erosion and sediment controls must be kept in place, inspected and maintained until final stabilization has occurred. Final stabilization is defined as 70% perennial vegetative cover over 100% of the project or when permanent building materials such as pavement, buildings, and structures cover all areas that have been disturbed.