KEY CONCLUSION: The main goal and purpose of a Phase 1 assessment is to determine the necessity of and the scope for a possible future Phase 2 subsurface investigation.
Phase 2 investigation refers to any subsurface or other sampling work that exceeds the scope of a Phase 1 ESA project. The ESA is simply an evaluation of environmental conditions based on available agency and other printed documents. A Phase 2 project may be needed to assess subsurface environmental conditions at a particular Property. This may be because of a known “pre-existing” condition such as the presence of an underground storage tank (UST), a sump (oil/water separators and clarifiers are types of sumps) used for chemicals, hydraulic lift or because the Property or an adjacent or up-gradient site is already a known leak case.
ERAS is sometimes asked to skip the Phase 1 process and perform a Phase 2 investigation. The basic purpose of a Phase 1 is to determine the need for a Phase 2 and ERAS believes the Phase 1 Environmental Site Assessment (ESA), or at least the historical research that would be performed for an ESA, is absolutely essential prior to conducting Phase 2 work for the following reasons:
The research may determine other environmental issues that could be present that could be addressed at the same time, resulting in lower overall project cost.
Details, such as construction specifications pertaining to the issue of concern, such as for USTs or sumps, may be found.
Historical research may indicate the uses of the Property, which includes the specific or likely chemicals that may have been used. These chemicals would therefore be the target for investigation and reduce the cost of laboratory testing for “everything under the sun”.
Phase 1 information provides defensible information regarding the need for and the scope of the Phase 2 investigation.
The effects of a Phase 1 or historical research are more likely to decrease than to increase the cost of a Phase 2 investigation. At the least, it provides data that can be used as legally defensible information to justify the scope and analyses that were performed for the Phase 2.