The Archaeological Impact Assessment (AIA) is a stage of cultural resource management focussing on the impacts a project may have on archaeological sites. It is conducted by a qualified professional archaeologist, involving the visual inspection and subsurface testing of a project area followed by an evaluation of identified archaeological sites in relation to development activities. An AIA may follow an Archaeological Overview Assessment (AOA), where documented archaeological sites or the likelihood of archaeological sites was noted. Ideally, AIA is initiated early in project design to allow adequate time for the implementation of site-specific recommendations.
In BC, an archaeological site must not be damaged nor artifacts removed except under a Heritage Conservation Act (HCA) permit. This also applies to an AIA, where subsurface testing may intercept buried archaeological deposits and artifacts collected. An archaeologist’s HCA permit outlines the methods they implement during AIA fieldwork, analysis, and reporting for the proposed project. The Archaeology Branch of the provincial government reviews applications and issues HCA permits. First Nations bands in whose territories a project is proposed also review and comment on HCA permit applications. Further, the archaeologist will apply for First Nations cultural heritage permits where bands have developed their own permitting systems.
The AIA fieldwork is conducted by crews composed of archaeologists and First Nations members. Following visual inspection, subsurface testing is initially conducted through manual shovel testing to discover and define the extent of buried archaeological sites. Where there is a likelihood of deeply-buried archaeological sites, mechanical procedures such as auger or backhoe testing may be implemented.
If archaeological sites are found, the artifacts are collected and to-scale maps are produced of the site area. Information is collected on the depth, extent, and type of artifacts recovered as well as any features encountered at the sites (e.g., cultural depressions, buried hearths, culturally-modified trees, etc.). In some cases, evaluative units measuring 1 m x 1 m may be excavated in a systematic manner to gain additional information about the archaeological deposits. Following fieldwork, the archaeologist makes site interpretations based on analysis of the artifacts and field data.
At this point, the archaeologist must evaluate and review the sites versus project plans so that management strategies can be formulated where impacts might occur.
An evaluation considers the sites’ significance relating to scientific, public, economic, historic, and ethnic variables. These relate to a site’s potential to generate understanding about human history; contribute to other disciplines or industries; provide educational, interpretive, or economic opportunities; and, reflect connections to current ethnic groups. Ethnic significance is typically determined through discussion with the applicable First Nations for Indigenous sites.
Project plans are then reviewed to identify the extent of possible impacts to archaeological sites. These include direct impacts such as mechanical blading of site sediments and indirect impacts like on-going erosion to site areas or artifact collecting due to increased public access. If it is determined that developments may alter a site, the management strategies take into account the type of impact, the level of disturbance, and the evaluated significance of the site.
The recommended strategies may include site avoidance, protection measures, excavation programs, and/or construction surveillance. With the exception of site avoidance, these strategies may involve additional, possibly significant amounts of archaeological work and HCA permits. It is always preferable to avoid or reduce impacts to an archaeological site both in terms of preserving a culturally-important, non-renewable resource and to the cost-implications for proposed projects.
At the conclusion of an AIA, an HCA permit-compliant report must be submitted to the Archaeology Branch for review. The Archaeology Branch will respond in writing about the recommendations and outline requirements for any additional archaeological work relating to the project. The report is also provided to applicable First Nations so they may remain knowledgeable about archaeological results and recommendations pertaining to their identified territories.
