ConnDOT: On-Site Mitigation for Transportation Projects

On-Site Mitigation for Transportation Projects
The Connecticut Department of Transportation (ConnDOT) is committed to meeting its legal responsibilities in accordance with environmental permits and to ensuring the protection of natural resources during, and following, the completion of construction of projects and maintenance activities. When environmental degradation, resulting from either human error or aggravated by nature, is identified, arresting and correcting the damage is of utmost concern to the Department. ConnDOT’s Office of Environmental Planning, (OEP) works to ensure that these legal responsibilities are met during construction, and that environmental impacts are avoided and minimized through the use of on-site mitigation techniques. OEP also works to make certain that permit conditions and environmental compliance requirements are adhered to during the construction stage of projects. The following is an overview of the environmental and construction mitigation measures utilized by the Department on all construction projects.

On-site mitigation measures for construction activities:
  • An erosion and sedimentation control plan designed in accordance with the 2002-CT Guidelines for Soil Erosion – Sediment Control (CT Council on Soil & Water Conservation) is prepared and approved. Such controls must be put into use before work can begin on the project.
  • No equipment or machinery should be refueled within 25 feet of any wetland or watercourse unless approved by the project engineer.
  • Measures to prevent construction debris, paint or other material from entering any wetlands or watercourses are undertaken before construction can begin. These materials are to be collected and disposed of in an environmentally safe manner in accordance with state and federal laws and regulations.
  • No degradation of adjacent wetlands or watercourses from materials being placed in or near them as a result of construction activities is allowed.
  • No equipment should ford streams. Where equipment frequently travels along stream banks and beds, washed stone shall be placed to minimize impacts.
  • Off-site disposal locations for materials and debris should be determined to be acceptable and outside of designated wetlands and watercourses. Approval of areas not outside of designated wetlands and watercourses must be approved by local, state and federal agencies.
  • Prior to commencement of any construction activity in a waterway, a construction sequencing plan and a water handling plan must be submitted in writing for approval. Water in the channel shall be kept at an appropriate depth and continuous flow to allow fish passage.
  • A written proposal for specific methods and devices to be used for dewatering activities must be submitted to the project engineer before those operations can begin. The engineer may cease dewatering operations if excessive turbidity becomes a problem.
  • Work within and adjacent to wetlands or watercourses shall be done during periods of low flow, whenever possible. The contractor shall make every effort to secure the work site before a major storm event, as defined by the National Oceanic and Atmospheric Administration Weather Service.
  • All temporary fill shall be stabilized during construction to prevent sediment or particulate matter from entering a wetland or watercourse. All areas affected by temporary fill shall be returned to their original contours or as directed by the engineer, and revegetated.
  • Within 7 days of setting the approximate final grade on slopes, seeding will be accomplished as determined by the engineer. If the grading operation will be suspended for 30 or more consecutive days, seeding or some form of soil stabilization will be required.
  • Provisions must be made for the collection, retention and proper disposal of drained oil, removed oil filters or other deleterious materials. All spills will be reported immediately to the Connecticut Department of Environmental Protection (DEP) by the contractor.
  • For pesticide and herbicide application, a proposed applicator’s name and license number must be supplied for approval. No application of pesticides or herbicides within 25 feet of a wetland or watercourse will be allowed
  • During spawning season, as defined in the contract, discharges and construction activities in spawning areas of state waters shall be restricted so as not to disturb or inhibit aquatic species which are indigenous to the waters.
On-site mitigation measures are taken in the field to avoid and minimize construction-related impacts to water resources. These measures are considered early on in the project design and are in addition to any special conditions or terms stated in permits from the DEP and the U.S. Army Corps of Engineers. The DEP, ConnDOT and its associated personnel and contractors work closely with one another to ensure the protection of water resources within a project area.
August 1998
Connecticut Department of Transportation
Office of Environmental Planning
2800 Berlin Turnpike
PO Box 317546
Newington, CT 06131-7546