Safe Drinking Water Act of 1944 (SDWA)
See Glossary of Environmental Laws
Safe, Accountable, Flexible and Efficient Transportation Equity Act - Legacy for Users of 2005 (SAFETEA-LU)
See Glossary of Environmental Laws
Saturated Soils
A condition in which all easily drained voids (pores) between soil particles in the root zone are temporarily or permanently filled with water to the soil surface at pressures greater than atmospheric. (USACE; Technical Report Y-87-1, Corps of Engineers Wetlands Delineation Manual, Department of the Army, Waterways Experiment Station, January 1987.)
Scoping Letter
Scoping is a formal coordination process, which determines the scope of issues to be addressed, and identifies the significant issues related to the proposed action. Scoping usually involves an internal meeting with NCDOT staff. It occurs early in the planning process and may involve agencies and interested public. The scoping letter is the first formal request for NCDOT staff to become involved in the planning process. Documented with formal meeting minutes.
Scrub-shrub Vegetation
1. Woody vegetation less than 20 feet tall. (Cowardin, L.M., et al., Classification of Wetlands and Deepwater Habitats of the United States, December 1979); 2. Shrub wetlands including areas dominated by woody vegetation less than 6 meters (20 feet) tall. The species include true shrubs, young trees, and trees or shrubs that are small or stunted because of environmental conditions. (Dahl, T.E. and C.E. Johnston, 1991. Status and Trends of Wetlands in the Conterminous United States, Mid-1970's to Mid-1980's. U.S. Department of the Interior, Fish and Wildlife Service, Washington, D.C.).
Secondary Effect
An effect or environmental impact from a proposed action that are caused by the action and are later in time or farther removed in distance but are still reasonably foreseeable. A secondary effect may include land use pattern changes resulting from the construction of a new highway, air quality changes within a locality, etc. Note: Secondary effect and indirect effect are used interchangeably; NCDOT uses indirect effect.
Secondary Nursery Area
Located in the lower portions of creeks and bays. As they develop and grow, young fish and shellfish, primarily blue crabs and shrimp, move into these waters.
Section 10 [of the Rivers and Harbors Act of 1899]
See Glossary of Environmental Laws
Section 106 [of the National Historic Preservation Act of 1966]
See Glossary of Environmental Laws
Section 303(d) Listed Waters [of the Clean Water Act of 1977]
See Glossary of Environmental Laws
Section 4(f) [of the Transportation Act of 1966]
See Glossary of Environmental Laws
Section 401 [of the Clean Water Act of 1977]
See Glossary of Environmental Laws
Section 401 Certification/Water Quality Certification
Section 401 of the Clean Water Act requires the states to issue a 401 Water Quality Certification for all projects that require a Federal Permit (such as a Section 404 Permit). The "401" is essentially a verification by the state that a given project will not degrade Waters of the State or otherwise violate water quality standards.
Section 404 [of the Clean Water Act of 1977]
See Glossary of Environmental Laws
Section 7 [of the Endangered Species Act of 1973]
See Glossary of Environmental Laws
Service Road
Also known as a frontage road that generally parallels a highway or through street. Businesses, such as gas stations, restaurants and motels, may be located along the service road. On occasion, a service road in rural areas may have been the original alignment of the highway prior to the construction of the freeway. (CG)
Shellfishing Waters
Also known as class SA waters, these are saltwater areas suitable for commercial shellfishing.
Shoulder Section
A roadway with an earth shoulder and a ditch on the outside of the pavement.
Significant Impacts
Any number of social, environmental or economic effects or influences which may be brought about as a result of the implementation of a transportation improvement that are of such a magnitude or degree of intensity or duration as to 'require' the preparation of an environmental impact statement under NEPA. 'Significant impacts' may include effects that are direct, indirect or cumulative and include both the short-term and long-term duration of the effect. FHWA project development and environmental planning requirements under transportation decision-making refers to the context of an action and intensity or the severity of impact (referring to criteria at 40 CFR 1508.2).
Significant Natural Heritage Program Area
A Significant Natural Heritage Area (SNHA) is an area of land or water identified by the N.C. Natural Heritage Program (NCNHP) as being important for conservation of the State's biodiversity. SNHA's contain one or more Natural Heritage elements - high-quality or rare natural communities, rare species, and special animal habitats. Approximately 25% of the SNHA's in North Carolina are entirely or partially in conservation ownership, including conservation easements. However, many remain privately owned and are unprotected from threats such as development.
A sill is a sediment retention device typically made of rock or concrete which is installed at the upstream end to one side of a culvert to create diversity in flow velocity, depth and energy dissipation patterns that aid fish passage. Sills are used as velocity control devices and can be used to restore the natural stream width after the installation of a culvert.
Slope Stakes
Point of reference indicating the earthwork limits on each side of the centerline of a roadway. The slope stake represents the intersection of the ground and each side slope.
1. A depression or hollow usually filled with deep mud or mire;
  2. A stagnant swamp, marsh, bog, or pond, especially as part of a bayou, inlet or backwater; or
  3. A local or regional term referring to a man-made, 'concrete' water conveyance system (e.g., a concrete-lined roadside ditch).
Soil and Erosion Plan
May also be referred to as a 'Soil Erosion and Sediment Control Plan'. A plan that addresses the construction related impacts from a project, including measures to reduce extensive areas of soil disturbance, identification of clearing and grubbing (construction) limits, installation of sedimentation devices such as silt fences, gravel or stone berms around drainage inlets/outlets, staked hay-bales, diversion swales, detention/retention ponds, etc., measures to re-grade, re-vegetate and stabilize exposed soils, and the use of other appropriate best management practices to minimize sediment runoff to streams, rivers and other water bodies or from high winds.
Special Aquatic Sites [under Section 404]
Wetlands, mud flats, vegetated shallows, coral reefs, riffle and pool complexes, sanctuaries, and refuges as defined in the CWA regulations at 40 CFR 230.40 through 230.45. These areas get special consideration under the guidelines at Section 404(b)(1) of the Clean Water Act that address avoidance, minimization and compensatory mitigation of waters of the United States.
Sponsor Agencies
[See Primary MOU Signatory Agencies]
Start of Study Letter
This letter officially initiates the coordination process between NCDOT and groups outside NCDOT. The letter solicits input from federal and state agencies (including the State Clearinghouse), local government agencies, and the public. Since these letters are sent early in the planning process, the level of detail provided is very general and usually only includes a TIP description and a vicinity map.
State (North Carolina) Environmental Policy Act (SEPA or NCEPA)
The purpose of the N.C. Environmental Policy Act is to provide a method by which decision-makers may consider environmental aspects and consequences of a proposed development. A review under SEPA may be triggered whenever a project meets the following criteria:
  1. Expenditure of public monies or use of public lands (includes submerged public bottom lands);
  2. An action (i.e. a State permit decision;
  3. A potential impact; and
  4. The project exceeds approved minimum criteria. State agencies may choose to establish specific minimum criteria designating minimum levels of environmental impact. Once these criteria have been approved, no filing of environmental documents is required for projects whose impacts do not exceed the criteria thresholds. If an agency establishes minimum criteria, the agency must review the criteria every five years and revise them as necessary. All proposed minimum criteria and revisions to minimum criteria must be approved by the Secretary of Administration prior to an agency's publication of Notice of Text under G.S. 150B establishing or revising such minimum criteria.
State Clearinghouse
The State Clearinghouse operates and manages the N.C. Environmental Review Process. The purpose of the process is to notify potentially affected state/local government agencies and the public of proposed activities in their jurisdiction and offer them the opportunity to review and comment on the adequacy of the environmental impact documents prepared for the proposals before final decisions are made. The State Clearinghouse provides the following services to carry out this process:
  1. Administers the state and local agency review and comment process for environmental review documents prepared pursuant to the National and North Carolina Environmental Policy Acts; and
  2. Publishes the North Carolina Environmental Bulletin (a bi-weekly summary of environmental documents currently being circulated for review and comment).
State Implementation Plan (SIP)
A term referred to under the Clean Air Act requirements that comprise the regulations and other materials for meeting clean air standards. A SIP may include State regulations that EPA has approved, orders requiring pollution control at individual companies, and planning documents such as area-specific compilations of emissions estimates and computer modeling analyses that demonstrate that regulatory limits can be met.
Statewide or Locally Important Farmland
A third designation under the Farmland Protection Policy Act (FPPA) that includes land identified by state or local agencies for agricultural use (e.g., Local Agricultural Districts), but are not of national significance. A specific discussion of avoidance measures in NEPA documents is not required for potential impacts to this agricultural land classification.
Statewide Planning Branch
See Transportation Planning Branch
Stormwater Management Plan
A Stormwater Management Plan protects sensitive waters by maintaining a low density of impervious surfaces, maintains vegetative buffers, and transports runoff through vegetative conveyances.
Strategic Highway Corridors (SHCs)
A set of primarily existing highways vital to moving people and goods to destinations within and just outside North Carolina. The corridors include 55 major or "parent" corridors along with the associated "spurs" (denoted by letters), totaling 5,378 centerline miles, including all existing and proposed interstates. These corridors only account for approximately 7% of the entire state-maintained highway system, yet they carry approximately 45% of the state's traffic.
Strategic Highway Network (STRAHNET)
The Department of Defense's Strategic Highway Network for moving military personnel and equipment. (SHC) This is a network of highways which are important to the United States' strategic defense policy and which provide defense access, continuity and emergency capabilities for defense purposes.
A general construction term used to describe the layer of materials beneath the asphalt, concrete or other final roadway surface (e.g., gravel or stone).
Submerged Aquatic Vegetation (SAVs)
Vegetation rooted in the substrate of a body of water (usually no deeper than 10 feet) that does not characteristically extend above the water surface and usually grows in associations or beds. It serves as a nursery area for juvenile aquatic species and supports adult populations of economically important seafood species. SAV beds also enhance water quality by reducing turbidity and stabilizing sediments. Also referred to as seagrass.
Substantive Comments
A phrase that may be used to describe the type or 'degree' of review comments. Under Merger, the phrase may be synonymous with 'Essential', 'Actual,' 'Substantial' or 'Firm' comments and typically involve regulatory concerns or issues identified by a review agency. Substantive comments may differ from other review comments in being less advisory in nature and more prescribed.
The elements of a bridge that support the superstructure of a bridge. Typically the substructure consists of a foundation, one or more columns, and a cap upon which the superstructure rests. The substructure units of a bridge may be referred to as end bents or abutments which are the end units that assist in tying the bridge to the approach roadway, or bents or piers which are those units supporting two spans of the superstructure where they join together.
Sulfur Dioxide (SO2)
A colorless, reactive gas produced when sulfur-containing fuels such as coal and oil are burned. For transportation related projects, diesel powered equipment and motors are most often associated with this priority air pollutant.
The banking of a roadway around a curve to counter some of the lateral centrifugal force.
The element of a bridge on which traffic, pedestrians or cyclists travel. The superstructure spans the creek, river, wetlands, road, highway or railroad. The superstructure may consist of rails or barriers, deck, and girders and rests atop the substructure. The structural element or the main element of the superstructure may be a structural slab, concrete or steel I-girders, concrete or steel box girders, voided slabs such as cored slabs or box beams, or others.
Supplemental Draft Environmental Impact Statement (SDEIS)
A DEIS that has been updated or 'supplemented' with new or revised information. Under NEPA, numerous documents may be 'supplemental', including EAs, FEISs, etc. Decisions to supplement EISs rest with the Lead Federal Agency.
Surface Waters
Water present above the substrate or soil surface. (USACE; Technical Report Y-87-1, Corps of Engineers Wetlands Delineation Manual, Department of the Army, Waterways Experiment Station, January 1987;).
A water drainage conveyance that directs stormwater drainage to receiving waters and/or holds it and allows it to gradually infiltrate into the soil.
A swamp is a wetland that features permanent inundation of large areas of land by shallow bodies of water, generally with a substantial number of hummocks, or dry-land protrusions. Swamps usually are regarded as including a large amount of woody vegetation. When a wetland area does not, it is usually termed a marsh.
System Linkage
With regards to the purpose and need of a project, this term refers to the need to provide roadway improvements due to discontinuity of the existing roadway network. For example, this may refer to the need to provide a more direct connection between activity centers or to create continuity in terms of facility type and function. Information about system linkage explains how the project fits in with the transportation system, including the relationship to other plans and other modes. Possible data to support this need includes roadway network discontinuity, travel time comparison, travel demand studies, Intra-state and Strategic Corridor systems, Military/Homeland security needs, and access needs.
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