Historic And Archaeological Resources

Historic And Archaeological Resources

The Connecticut Department of Transportation (ConnDOT) and the Federal Highway Administration (FHWA) view archaeological sites and historic structures as important components of the cultural heritage of the state. Working with the Connecticut State Historic Preservation Office (SHPO), the National Park Service (NPS), the Advisory Council on Historic Preservation (ACHP), which is a part of the federal executive branch, and local officials, ConnDOT makes every effort to identify resources which are on or eligible for listing in the National Register of Historic Places and to avoid affecting them. When they cannot be avoided, ConnDOT coordinates with these same agencies and officials to

  1. identify the value of the resource and the estimated effect of the action on it, and
  2. develop and implement measures to minimize harm and techniques to mitigate construction impact on affected resources.

Archaeological Resources

There are two basic types of archaeological sites: pre-historic (prior to European settlement) and historic (subsequent to European settlement). The latter is often associated with a building or bridge that once occupied the site.

In two discrete phases, ConnDOT investigates and documents existing material and traces of cultural activity at archaeological sites affected by construction work. This is done in accordance with the methodology prescribed in the "Environmental Review Primer for Connecticut's Archaeological Resources" prepared by SHPO.

Phase 1: Archaeological Assessment and Reconnaissance Survey

The general scope of work includes:

  • walk-over
  • (photographic documentation, visual evaluation, hand-auger testing),
  • background investigation
  • (searching state/local archives, published literature, land records, historic maps/photographs and existing collections, and interviewing local officials/historians),
  • sub-surface investigation
  • (excavating test pits to define the boundaries of cultural material and permit sampling and lab analysis), and
  • a written report
  • (stating the findings and a recommendation whether to investigate further and, if so, what action to take).

Phase 2: Intensive Archaeological Survey and Data Recovery

The general scope of work includes:

  • supplemental background investigation
  • (expanding the literature search to additional sources),
  • more extensive sub-surface investigation
  • (digging test pits and/or excavation units to systematically remove, analyze and catalogue a representative sampling of material occupying the archaeological site or all the material if performing data recovery; prior to being archived at the Office of the State Archaeologist at the University of Connecticut), and
  • a written report
  • (stating findings and a recommendation whether to investigate further and recover more material or to employ preservation-in-place)

Historic Structures or Sites

Historic structures are those that exhibit architectural merit or are associated with a person, event or use of historical significance. Bridges may, in addition, be determined historic because of their type of design or construction. The ruins of such structures, or the location of an event, are referred to as historic sites. A building, bridge or site generally must be at least fifty years old to be eligible for historic designation.

Historic documentation includes:

  • photographs
  • (depicting the resource from several viewpoints, interior and exterior, prior to commencement of work), and
  • a written narrative
  • (describing the design, construction, use and history of the resource, as well as each photographic view, indicating the viewpoints and sight line of each on an index plan).

Documentation is of two types: state-level (in accordance with SHPO requirements) and federal-level (in accordance with NPS requirements). The procedure is similar for both, but federal requirements for detail and documentation are greater.

Section 106 and Section 4(f)

§106 of the National Historic Preservation Act (administered by SHPO and NPS) and §4(f) of the U.S. Department of Transportation Act (administered by FHWA) are the controlling laws regarding historic resource documentation.

§ 106 requires that all historic and archaeological resources potentially affected by a project be identified, the effect assessed and ways to minimize, or avoid, harm be developed. §106 also stipulates the requirements for photographic and written documentation of affected buildings and bridges for the Historic American Building Survey and the Historic American Engineering Record.

A project deemed detrimental to historic resources is noted as having an "adverse effect" and triggers a § 4(f) evaluation. § 4(f) requires that for those resources actually affected by the project, a description of the resource, the type and magnitude of the impact and proposed methods of protection, restoration and enhancement be detailed.

A Memorandum of Agreement is also executed, in which ConnDOT and FHWA agree to carry out archaeological investigation and historic documentation according to the directives of SHPO and the specifications of the ACHP.

In a project containing § 4(f) resources, an alternative which avoids impact to such resources must be included and assessed. For example, if it is proposed to realign an existing roadway, which passes through a historic district, and at least one § 4(f) resource would be affected, an alternative alignment, completely beyond the district's boundary, must be evaluated as well. These alternative alignments can affect other resources such as wildlife and wetlands.

Impact is categorized as one of the following:

  • Total Taking
  • (requires the acquisition of the entire historic resource property; ConnDOT offers relocation assistance to affected families and businesses. Consideration is given to moving the historic structure),
  • Partial Taking
  • (requires the acquisition of a portion of the historic resource property),
  • Construction Easement
  • (does not require the permanent acquisition of any portion of the historic resource property, but, because of roadside grading, may affect trees, lawns, stone walls, fences, or overall historic setting), or
  • Constructive Use
  • (occurs when construction interferes with the historic resource so severely that its intrinsic attributes are substantially impaired).


test pit (Phase 1): a methodically hand-dug excavation for the purpose of locating, removing and documenting pre-historic or historic cultural material; pits are laid out in a linear or grid pattern.

excavation unit (Phase 2): similar to a test pit, but many times the volume and at a spacing appropriate to the Phase 1 findings; may also be dug as a linear trench.

preservation-in-place: backfilling the excavation to protect the found material in its context for future study; used when material of significance is encountered, but the construction work will not directly affect it.

August 1998

Connecticut Department of Transportation

Office of Environmental Planning

2800 Berlin Turnpike

PO Box 317546

Newington, CT 06131-7546