Abstract:
In early February 2018, a contractor performing restoration work on a communications tower in Seattle,
Washington, deviated from the written work plan and accidentally released lead-containing paint chips
onto 40 residential and commercial properties in the surrounding neighborhood. Clean-up and
remediation was conducted in the neighborhood with collaboration between the EPA, EPA contractors,
the communications tower owners and station owners, remediation contractors, and neighbors.
Once remediation efforts were completed, tower preparation and painting work was resumed by a new
tower restoration contractor in late July. Wood Environmental and Infrastructure Solutions, Inc. (Wood)
was also contracted to monitor the neighborhood for releases of lead paint chips during the restoration
work. The monitoring work involved inspecting for chips and paint in residential yards and public areas
surrounding the tower. Wood personnel also documented data on the chips collected such as: the
quantity of chips per day; daily total chip weights; and approximate chip location and inspection area.
Daily records were kept of weather conditions and work activities being conducted on the tower.
Three different control measures were used to limit the release of paint drops and paint chips from the
tower to the neighborhood. The new tower contractor initially used glove bags around localized work
areas on the tower to limit the release of chips into neighborhood. However, a significant amount of
large chips were still being found in the neighborhood. A floor shroud was subsequently installed under
the work area to catch falling chips in addition to the glove bags. During the last month of the project
mesh walls were added to the floor shroud to encompass the entire work area.
The collected chip data was used to assess the effectiveness of each control and assess whether wind
and work activities correlated with the release of chips. The use of a floor shroud decreased the mass
per day by 50%, and this was further reduced by another 40% with the addition of mesh walls.
However, the use of shrouds increased the total amount of chips found on the ground during inspection
due to new lead-free paint drying on the shroud and being dispersed into tiny fragments. An increase of
74% of chips was observed when the floor shroud was introduced as a control. The size of these chips
were significantly smaller and confirmed by chip data that showed a 78% decrease of weight per chip
when the floor shroud was introduced. The chip mass and total amount patterns were observed in the
field and confirmed by chip data analysis. Observations from field inspection also seemed to indicate
that windier days and days that involved scrapping of chips on the tower resulted in more chips found
during inspection, however these observations were not supported by the chip data analysis.