Deck Drains
Drains (usually 6-inch vertical pipes) located in a bridge deck to drain water off the bridge. The drains can also be placed horizontally (usually 4-inch pipes) through the bridge rails.
DeMinimus Impact (4f)
Under SAFETEA-LU, the Secretary can comply with Section 4(f) in a streamlined manner by finding that the program or project will have a "deminimus" impact on the area - i.e., there are no adverse effects of the project and the relevant State Historic Preservation Officer or other official with jurisdiction over a property concurs.
Department of Transportation Act of 1966 [Section 4(f)]
See Glossary of Environmental Laws
Design Speed
A selected speed used to determine the various geometric design features of the roadway. The assumed design speed should be a logical one with respect to topography, the adjacent land use, the classification of the highway and the anticipated operating speed.
Design-Build Process
A construction project that combines two usually separate services into a single contract. Design-build allows an agency to contract a team of both designers and a contractor to simultaneously design and construct a project. The design-build entity may be a single firm, a consortium, joint venture or other organization assembled for a particular project. (CG)
Detailed Study Alternatives [Carried Forward] (DSAs)
Under the Merger Process, DSAs are preliminary alternatives found to be reasonable and feasible transportation alternatives that are studied and evaluated in greater detail for presentation in the environmental document. The alternatives selected and to be further considered under Concurrence Point 2.
Detention Ponds
Ponds that are sized and configured to provide significant removal of pollutants from the incoming stormwater runoff. They maintain a permanent pool of water that is designed for a target sediment removal rate according to the size and imperviousness of the contributing watershed. Water is released at a rate such that downstream erosion is lessened.
Direct Effects
Effects caused by the action and occurring at the same time and place (40 CFR 1508.8). Changes in noise levels, fill discharges in wetlands and relocations of homes and businesses are some examples of direct effects. Used interchangeably with Direct Impacts. NCDOT will normally use Direct Impacts in the Merger Process. Other agencies may consider that when an effect is quantified it becomes a direct impact.
Disposal Areas
[See Waste Areas] The disposal site for surplus excavated materials. Waste and debris is disposed of in areas outside of highway right of way and the areas are to be provided by the contractor.
Disturbed/Maintained Land
A general land use category contained in environmental documents that includes lawns, parking lots, cleared areas, and other properties which have been substantially altered or developed. It does not include terrestrial forests, wetlands, prime farmlands and other specific natural resource land uses.
Division Environmental Officer (DEO)
As of 2001, all NCDOT Divisions have a DEO. The DEO Program's functions are to increase environmental stewardship, assist with obtaining permits, build relationships with local agencies, and provide environmental training.
Division of Air Quality (N.C. DAQ)
See Acronym Cross Reference
Division of Coastal Management (N.C. DCM)
See Acronym Cross Reference
Division of Community Assistance (N.C. DCA)
See Acronym Cross Reference
Division of Forest Resources (N.C. DFR)
See Acronym Cross Reference
Division of Marine Fisheries (N.C. DMF)
See Acronym Cross Reference
Division of Water Quality (N.C. DWQ)
See Acronym Cross Reference
Draft Environmental Impact Statement (DEIS)
The preliminary environmental document prepared by a State or Federal agency on the environmental impacts of its project and/or program proposals. The general FHWA criteria for preparing DEISs is found at 23 CFR 771.115 and the procedures for issuance at 23 CFR 771.123.
Drilled Pier
A deep foundation designed to support loads from a bent by distributing those loads to surrounding soils. A drilled pier is constructed by placing fluid concrete and reinforcing steel in a drilled hole.
Drilled Shaft
See Drilled Pier
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