Phase I and Phase II ESAs
Phase I ESA Supplement and Phase II Drilling and Sampling, City of Orlando
HSW Engineering, Inc. was selected by the City of Orlando (City) in April 2003 to be one of their three Environmental Assessment, Testing and Remediation Service contractors. On April 7, 2004, the City directed HSW to review voluminous documentation regarding a large downtown property (61 West Washington Street) that the City planned to redevelop, update a Phase I Environmental Site Assessment (ESA), prepare a cost-effective Phase II ESA scope of work and Health and Safety Plan, and implement the Phase II scope in accordance with ASTM 1903-97 to facilitate pre-development planning. The updated Phase I information, including City Directories obtained by HSW at the Orlando County library, was used to select Phase II sample locations. The phase II sampling activities were designed to rapidly determine the potential presence and extent of groundwater impacts from historic industrial activity in the area, because dewatering and groundwater disposal was planned during construction.
Because VOAs and VOHs were detected beneath other nearby sites that HSW researched as part of the Phase I work effort, and HSW determined groundwater flow and constituent concentration gradients, HSW was able to cost-effectively determine that off-site sources of contaminants existed, and delineate the extent of onsite impacts with limited data.
HSW reviewed City construction plans and prepared recommendations to the City with plans to avoid impacted areas and slightly modify redevelopment dewatering and site-development plans, including treatment of environmental media with constituent concentrations exceeding FDEP's natural attenuation default source criteria as required.