Human Health Risk Assessment - Raytheon

Executive Summary
1
Human Health Risk Assessment
DRAFT
The purpose of this report is to evaluate the potential risks from exposure to Site-related
constituents under current and likely future exposure conditions in conjunction with the SARA in
support of an appropriate remediation plan to be submitted to the Florida Department of
Environmental Protection (FDEP). The levels of exposure estimated in this report are based on
extensive sampling data that has been collected to date and are summarized in the Site
Assessment Report Addendum (SARA), prepared by ARCADIS, to which this report is attached.
This risk assessment addresses Site occupants, outside workers and visitors, as well as
residents surrounding the Site, who could be exposed to Site-related constituents. This report
also includes a qualitative analysis of non-human receptors.
To complete this type of an assessment, a series of health-protective assumptions about
exposure characteristics must be made. The assumptions used in this assessment have been
chosen to be health protective, and intentionally conservative, and therefore tend to
overestimate the calculated non-cancer and theoretical excess cancer risks.
Current and likely future on-Site receptors include workers at the facility who spend the majority
of their time indoors, on-Site landscape workers who spend most of their time outdoors, contract
workers who may be required to perform subsurface excavation activities to maintain existing
underground utilities or support construction activities, and adolescent trespassers.
The primary potentially complete exposure pathway for on-Site facility workers is the inhalation
of constituents that have volatilized from shallow groundwater and entered indoor air. Only
chemicals present at the surface of the groundwater are susceptible to volatilization to indoor
air.
For on-Site landscape workers and potential adolescent trespassers, the primary exposure
pathway is inhalation of outdoor air. Because there are currently no irrigation wells on-Site and
no planned excavation of soils to a depth below the water table, there is no direct exposure to
on-Site groundwater for these receptors under current exposure scenarios. Some subsurface
excavation may be required to maintain/upgrade existing utilities on-Site and commercial utility
or construction workers could be exposed to COPCs via direct contact with subsurface soils and
shallow groundwater, which may be found at 1.5 to 4 feet bgs. In addition, workers may be
exposed to COPCs volatilized from exposed shallow groundwater during excavation.
The potential area of impacted groundwater extends to the east beneath the Pinellas Trail, the
Stone’s Throw Condominium Complex, and the Brandywine Apartments Complex as well as to
the south and west beneath Azalea Park, the ball field area, and some residential properties.
However, the impacted groundwater to the south and west is present below a clean water layer
which prevents volatilization of COPCs from the water table and eliminates potential exposures
to COPCs in deeper groundwater.