The National Environmental Policy Act (NEPA) was signed into law by President Richard Nixon on Jan. 1, 1970. It was one of the first laws written to protect the environment, ensuring that federal agencies undertake an assessment of the environmental effects of their proposed actions prior to making decisions. Those decisions can include, but are not limited to, decisions regarding permit applications, federal land management actions, and construction of publicly owned facilities. Federally funded projects that require NEPA documentation can include airports, buildings, military complexes, highways, parkland purchases, and other federal activities.
The following account of an environmental assessment for a roadway project illustrates the range of factors that often need to be considered to comply with NEPA.
The state of Tennessee has seen significant tornado activity over the years, some leaving massive devastation in their wake. Madison County, located about 70 miles northeast of Memphis, is one particular area that has been affected repeatedly. Unfortunately, debris from these storms often blocks US 45, the lone route crossing a major river, leaving southern portions of the county completely cut off from emergency services.
Following a major tornado in 2003, the City of Jackson, Madison County, and the Metropolitan Planning Organization (MPO) agreed that a need existed for improved access between north and south Jackson for both congestion and safety reasons. At that time, the city initiated discussions with the Tennessee Department of Transportation (TDOT) about a possible southern extension of the existing US 45 Bypass (State Route 186), a major four-lane facility that currently ends at US 45 just south of city hall. The new bypass extension will provide an alternate route to and from south Jackson for through traffic and an alternate route in the event of an emergency blocking the US 45 crossing of the South Fork of the Forked Deer River.
Currently, there are only two crossings of the South Fork of the Forked Deer River connecting north and south Jackson. US 45 serves as the only major north/south crossing in the area, connecting downtown Jackson with residential, commercial, and industrial development and the community of Bemis, all south of the river. Riverside Drive provides the only additional crossing of the South Fork of the Forked Deer River. On occasion, Riverside Drive is blocked due to flooding of its lower-elevation bridges and roadway. In addition, Riverside Drive does not have the facilities or capacity to serve as an alternate route when incidents close US 45. This road has only two narrow lanes and little or no shoulders along the route.
As part of an early planning study, TDOT evaluated a number of alternatives for the Southern Extension of the US 45 Bypass. In 2004, regulatory agencies reviewed alternatives developed and concluded that acquiring permits for a new crossing of the South Fork of the Forked Deer River and associated wetlands would be difficult and recommended that the city consider following the existing Riverside Drive for the new bypass.
In 2009, Gresham, Smith and Partners (GS&P) began the NEPA process for the City of Jackson to look at potential impacts to the social and natural environment within the project area, and develop build alternatives to be evaluated in the Environmental Assessment. Building on the alternatives previously considered, the project team developed a single build alternative with two options to connect to existing US 45 at the northern project terminus.
The alignment begins at a proposed intersection with US 45 about 2.17 miles south of the South Fork of the Forked Deer River (Figure 1). The proposed alignment goes west from US 45, then turns north to follow Riverside Drive until it ties into the existing US 45 Bypass, ending at the intersection with Airways Boulevard (US 70). It runs along new alignment as well as following existing Riverside Drive. The new roadway is 5.25 miles long with a realigned connection to State Route (SR) 18 near the southern terminus, adding an additional 1.53 miles to the project length, for a total length of 6.78 miles.
The corridor has two options to connect to US 45 – the build alternative and the build alternative with option C-1. The build alternative begins on a new location, parallel to the north side of the river. The road is proposed to be at-grade or on fill, continuing north to connect with the existing bypass, just south of Airways Boulevard.
The second option (C-1) follows Riverside Drive farther north, tying into the existing US 45 Bypass east of State Street, then following the existing bypass to Airways Boulevard. This option C-1 was considered to minimize the length of the bypass extension, to avoid a National Priority List (NPL) hazardous materials site, and to provide a more direct connection to the existing US 45 Bypass than Corridor C.
The build alternative was evaluated for direct, indirect, and cumulative impacts to the environment. There were many environmental and constructability issues involved, the majority of which were located in the area where the alternative will follow Riverside Drive. This particular section passes through a large area of floodplain and wetlands adjacent to the South Fork of the Forked Deer River. Issues that had to be considered during alternative development included:
- constructing the road above the 100-year floodplain;
- potential impacts to an electric line and 10-inch gas main, both running along the east side of Riverside Drive;
- two sites along the alignment that are listed on the National Register of Historic Places (NRHP);
- 15 streams impacted by the project;
- 28 wetlands identified in the project area;
- an NPL site in a brownfields agreement is located at the northern terminus of the alignment; and
- a site that has been under remediation measures since 1992 for benzene contamination is located at the northern terminus of the alignment.
After consultation with state and federal agencies, GS&P recommended measures to mitigate the issues that include the following:
Floodplain – The grade of the existing roadway will have to be raised above the 100-year floodplain. Along Riverside Drive, a series of new bridges and overflow structures are proposed to replace the existing structures as the grade is raised and the roadway widened.
Utilities – Riverside Drive will be widened to the west side only in order to avoid substantial impacts to the utilities to the east and to allow the roadway to remain open during construction.
Historic – The Riverside Cemetery, located at the intersection of Sycamore Street and Riverside Drive, was added to the NRHP in 2003. Established in 1824, the cemetery is the resting place for many of Jackson’s founders and earliest leaders. Due to the historical significance, the proposed alignment will avoid taking property from the cemetery and, therefore, will not have a physical impact.
The Bemis Historic District, located south of the City of Jackson and to the east side of Riverside Drive, was listed in the NRHP in 1991. Bemis holds historical significance because it was originally developed as a model industrial village to support the cotton spinning mills of the Jackson Fiber Company. The district is approximately 455 acres in size and contains 523 contributing properties. To avoid impacting the Bemis Historic District the proposed alternative will be located to the west of this site.
Water – The project will affect 15 streams including Meridian Creek, Bond Creek, and the South Fork of the Forked Deer River. Where avoidance is not feasible, streams will be bridged or placed in culverts and will require mitigation by permitting agencies.
Wetlands – There are 28 wetlands identified in the project area, consisting primarily of forested wetlands. Of those 28 wetlands, 25 will be impacted by the project. Due to the need to utilize Riverside Drive roadway, avoiding the wetlands in the area would not be practical. The build alternative will impact 38.56 acres of the wetlands area, and the build alternative with option C-1 will impact 24.08 acres of the wetlands area.
Each wetland was evaluated for avoidance and minimization measures. Steepened roadside fill slopes, a narrower roadway cross-section with a median barrier, retaining walls, and minor shifts in alignment are all being considered to reduce wetland impacts. Some existing wetland areas will be spanned to preserve wetland integrity. Bridge construction with methods such as “top-down” or “progressive” construction, which substantially minimize impacts to wetlands and alleviate the need for a haul road, are also being considered. Mitigation will be required by permitting agencies.
Hazardous materials sites – Former American Creosote NPL Site is in a brownfields agreement with the Tennessee Department of Environment and Conservation (TDEC) for property reuse and clean up. Approximately eight acres of the 30-acre site of creosote material were excavated, solidified, placed onsite, and capped. Subsurface investigations indicate creosote present at depths of 60 feet below ground surface. Therefore, excavation of the site for treatment was not cost effective and treatment has been in-situ (in place). The proposed build alternative will traverse the southwest corner of the property. However, the build alternative with Option C-1 will not impact the NPL site.
TDEC indicated that construction of the road on fill over the southwest corner of the property is acceptable. However, no piling can be driven within the contaminated area for bridge foundation construction.
A former Coca-Cola Bottling Company plant is located within the right-of-way of the build alternative Option C-1. This site has been under remediation measures since 1992 for benzene contamination. There is currently a dual-phase extraction system being used to pump groundwater to volatize the benzene to lower levels. Measures to avoid this site will be taken if Option C-1 is selected.
In 2005, the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU) High Priority Projects (HPP) Program provided $4 million in federal funds for the Southern Extension of US 45 Bypass. In July 2007, the city requested assistance from TDOT and has received matching funds for the early stages of the project’s development. The Environmental Assessment has been approved, and the project is awaiting additional funding to become available to move forward.
Sandy Layne-Sclafani, P.E., CPESC, is a senior civil engineer in the Nashville, Tenn. office of Gresham, Smith and Partners. She has more than 25 years of environmental and civil engineering experience. Her work with GS&P involves preparing NEPA documentation; transportation planning reports; environmental permitting (NPDES, ARAP, UIC, USACE 404); erosion prevention and sediment control inspections; preparation of stormwater pollution prevention plans and spill prevention control and countermeasures plans; and environmental site assessments.