The National Historic Preservation Act of 1966 (NHPA, and amendments) Section 106 requires Federal agencies to take into account the effects of their sponsored undertakings on cultural resources/historic properties (including archaeological sites, buildings/structures, monuments, etc.). This act only affects construction and developments that will either utilize federal funds or will seek to obtain a federal permit. You can read the entire act as amended August 5, 2004 here.
Initiating the Process
Once it has been determined that a project will require compliance with cultural resource regulations, the responsible party (i.e., developer, state or federal agency, representative cultural resources consultant) must initiate consultations with the State Historic Preservation Office (SHPO). The SHPO will require a description of the proposed project and maps showing its location. This information will be used to determine what level of cultural resources investigation will be necessary to meet the state’s Section 106 requirements. Unless a project area has been previously investigated for cultural resources or has already been developed, it is likely that the SHPO will require an intensive (Phase I) cultural resources survey. If such an investigation is necessary, a professional cultural resources management firm (CRM) must be hired to conduct it. The SHPO can provide a listing of CRM firms active in your area.
As this process can be time consuming, early coordination is important. Involving a professional cultural resources consultant early in the planning stages can allow for a proactive approach to this compliance area. A consultant would be able to identify potential cultural resource related complications, by conducting archival research and a field reconnaissance, and develop a Scope of Work that can then be presented to the SHPO as part of the initial correspondence. This can often speed the SHPO consultation process and provides a “head start” on further investigations, if they are necessary.
Phase I Survey
A Phase I survey is comprised of systematic pedestrian examination of the investigation area. All exposed ground surface is comprehensively examined for the presence of artifacts. Subsurface observations are made through excavation of 30 cm (12 in) diameter shovel tests at varying intervals (usually 30 or 60 meters [98 to 196 ft]), in a grid over the entire project area. These shovel tests are excavated to sterile subsoil (commonly red clay or light tan/white sand). All dirt fill removed from these tests is screened through 1/4 inch hardware mesh. Notes on soil type (e.g., texture, color, compaction) and the presence or absence of artifacts are recorded in field notebooks. All artifacts are recovered and sealed in labeled acid free bags.
If artifacts or other indications of human activity (i.e., standing structures) are identified, the resource will be fully defined and mapped. Site boundaries are determined by a number of factors. For instance, if the resource is a historic building/structure, the boundaries would encompass the building and any related features (e.g., outbuildings, well). In the case of archaeological sites, the boundaries are established by the absence of artifacts or by specific landforms that form natural barriers.
Once the resource is defined, it must be evaluated for its significance and eligibility for the National Register of Historic Places (NRHP). NRHP eligibility criteria are specified in Department of the Interior Regulation 36 CFR Part 60: National Register of Historic Places. This criteria states that cultural resources can be considered significant (i.e., eligible for the NRHP) if they “possess integrity of location, design, setting, materials, workmanship, feeling, and association,” and if they:
(A) Are associated with events that have made a significant contribution to the broad pattern of history; or
(B) Are associated with the lives of persons significant in the past; or
(C) Embody distinctive characteristics of a type, period, or method of construction, or represents the work of a master, possess high artistic values, or represents a significant and distinguishable entity whose components may lack individual distinction; or
(D) Have yielded, or may be likely to yield, information important in prehistory or history.
A battlefield may be considered eligible under Criterion A, whereas houses and structures are generally evaluated relative to Criteria B and C. Archaeological sites are usually evaluated under Criterion D and may be eligible if it “has been used as a source of data and contains more, as yet unretrieved data” (NRHP publication). In other words, under Criterion D, level of significance can be defined as research potential. The research potential of an archaeological site (lacking architectural remains) can be determined by demonstrating that the site retains intact archaeological deposits, such as culturally or temporally diagnostic artifacts (e.g., projectile points, decorated ceramics), intact features (e.g., hearths, storage pits), discrete artifact clusters denoting activity areas, or preserved organic material (i.e., plant remains, bone) associated with the site occupation.
Occasionally, Phase I survey data is insufficient to determine the NRHP eligibility of a resource. This situation occurs most frequently with archaeological sites. If additional data is necessary to define the significance of a site, it will be considered potentially eligible pending further evaluation and a Phase II testing investigation may be instigated.
Phase II Testing
Phase II testing of an archaeological site may involve a variety of activities, the goal of which is to determine the research potential of the site. The activities may include short interval (5 m [16 ft]) shovel testing, excavation of large shovel tests (50×50 cm [20x20 in]), machine scraping or trenching, or excavation of 1 by 1 meter (3.3×3.3 ft) units. These tasks provide additional data from which a NRHP eligibility recommendation can be made.
How does the NRHP eligibility of a site impact the proposed project?
If a resource does not meet NRHP eligibility criteria, it is recommended ineligible and no further work is required. The project can move forward without further consideration of that resource. If a resource is recommended eligible for the NRHP and the SHPO concurs with that recommendation, avoidance of the resource vicinity should be sought. Preservation in place of eligible resources is always the best option and can often be accomplished through modification of design plans, and/or green spacing. If avoidance is not possible, any adverse impacts to that resource must be mitigated. Mitigation can take many forms, including detailed photo-documentation and architectural drawings in the case of significant buildings or full-scale data recovery excavations at significant archaeological sites. Although mitigation can be time consuming and costly, once completed, the project can move forward without further consideration of the significant resource.