Phase I: Site Identification - Phase I surveys are designed to determine if archaeological resources are present within your project area. The methods used to locate archaeological sites depend upon the type of ground and surface conditions within the project area. In agricultural areas, fields are plowed and disked, and the exposed soils are examined for the presence of artifacts. In areas where plowing is not possible, such as wooded areas or residential areas, archaeologists dig shovel test pits (STPs) at regular intervals (typically 50 ft) across the project area. Soil removed from STPs is screened to recover artifacts if present.
Phase II: Site Evaluation - Phase II surveys are designed to collect additional information on archaeological sites already discovered. The additional information is used to evaluate the importance of the archaeologcial site and to determine if the site is potentially eligible for listing on the National Register of Historic Places. The importance or research value of an archaeological site is judged against a set of standards established by the U.S Department of Interior National Register Program. Only those archaeological sites determined to contain significant research potential are designated as National Register eligible. Phase II surveys typically expand the area excavated during the Phase I survey to collect a larger sample of artifacts, and to look for evidence of subsurface refuse pits, fire hearths, foundations, and other structures created by the site's inhabitants.
Phase III: Mitigation of Adverse Effects - Archaeological mitigation seeks to preserve important information contained in National Register eligible sites that will be adversely affected by the development project. One form of mitigation is to redesign the development project so that ground disturbing activities will avoid the archaeological site. Avoidance is often the most logical and least expensive form of mitigation. If the development project cannot be redesigned then a Phase III Data Recovery Plan is negotiated and agreed to through a formal Memorandum of Agreement. The Data Recovery Plan is a research plan designed specifically for the archaeological site being mitigated. A typical Data Recovery Plan includes the excavation of a significant portion of the archeological site, and the analysis and interpretation of the artifacts and features discovered by the Phase III investigation.
The Pennsylvania State Historic Preservation Office (PA SHPO) is the state review agency for archaeological surveys conducted in Pennsylvania. Detailed descriptions of archaeological requirements and survey methods are provided in PA SHPO's 2016 guidelines:
Guidelines for Archaeological Investigations in Pennsylvania (1.6 MB - .pdf )