Much environmental stewardship practice in construction over the past thirty years has focused on erosion and sedimentation controls and protection of water quality. Virtually every DOT now produces guidance for design engineers on design of stormwater pollution prevention plans and implementation and maintenance of stormwater best management practices (BMPs). The cutting edge in stormwater protection is now focusing on ensuring 100 percent compliance with these practices at construction sites; Maryland State Highway Administration and Caltrans, many of whose practices are included in this Chapter, lead the way in this regard. While links to some of the best on-line resources in water quality protection are included herein, this Chapter focuses on the wider range of environmental stewardship practices in construction, which are less common than erosion and sedimentation control and for which resources are sometimes harder to find. As Knuth et al. noted in their 2006 TRB presentation, “[r]econstruction of highways has huge environmental impacts: first in terms of the direct impacts of the construction, and secondly the impacts of increased congestion caused by necessary lane closures and detours.” [N]

These general practices have been collected from multiple DOTs and from requirements by federal land management agencies to protect the environment in the course of construction:

• Select the right equipment for the job.

Establish an emergency notification program.

• Before beginning a project, conduct an on-site meeting. At a minimum, include team members with vegetation, local climate, and soils knowledge.
• Avoid earthwork in saturated soils. When possible, schedule heavy equipment work during periods of low precipitation.

Develop and implement BMPs for mobile operations common to the construction of a project as well as the earthwork: include asphalt recycling, concrete mixing, crushing and the storage of materials, as appropriate to control the individual situations these mobile operations can create.

Inspect project work daily.

• Consider the following often overlooked erosion and sedimentation control areas:
  • Round the top edge of a slope failure, which is often a vertical face. For project success, it is critical to address this “initiation point” or persistent source of erosion by removing or rounding off the slope overhang.
  • Smooth all eroding areas such as rills or gullies. In addition, prepare a seed bed by slightly roughening Do this by raking across the slope face, not downhill.
  • Create terraces when slopes exceed 35 percent. Dig these terraces 10 to 14 inches deep across the slope face. Horizontal spacing usually varies from 14 to 10 feet depending on conditions. The steeper the slope, the closer the terraces should be to one another. The objective is to accelerate establishment of plants by reducing the slope angle of the planted locations.