The Phase III archaeological data recovery or mitigation effort represents the most intensive level of archaeological investigation offered by P2P Environmental.

When an archaeological site is considered significant and avoidance of the site is not possible, a data recovery or adverse effects mitigation may be undertaken. Through this process, the archaeological site undergoes intensive controlled sampling typically through the excavation of large uniform pits, surface collection, and sometimes mechanical stripping. Ideally, enough data will be recovered from excavations at this phase to answer research questions. Mitigation, in lieu of data recovery, can also be performed. This is done through consultation and agreement with federal, state, local, and tribal authorities to safeguard the site from any adverse impacts. Mitigation plans vary widely as no one mitigation plan is correct for each site.