Washington State Department of Ecology |
Toxics Cleanup Program |
Site Information
Tacoma
Smelter Plume
Vashon
Island School District
Child Use Area Resampling
Background
This summer, Vashon School
District and the Department of Ecology collaborated to evaluate the
effectiveness of cleanup efforts undertaken by the Vashon Island School District
on some key areas children play and learn in, such as the Kindergarten Play Area
and gardens. This sampling is a follow-up to sampling completed two years ago.
The school district initiated the effort, and paid for sample analysis, Ecology
provided technical support in planning, collected samples, and evaluated the
results of the updated information.
Introduction
In 2001, soil sampling as part of the
Vashon-Maury Island Child Use Area Studyfound arsenic in the soil at Vashon Island School District properties above the state
cleanup level of 20 ppm, but below the level that triggers more immediate action
– 100 ppm. The Vashon School District decided to clean up some selected areas
where children play or garden. In general, the School District mixed the
contaminated surface soil with clean soil to reduce the levels of arsenic.
This summer, the Washington State Department of Ecology and
the Vashon Island School District teamed up and sampled the three “remediated” areas
and the elementary school garden. Ecology, with the assistance of Public Health
– Seattle & King County, wrote the sampling plan, collected the samples, and
evaluated the results. The School District paid for the sample analysis.
Study Results
Not unexpectedly, the results are mixed.
-
A grass strip where children play at Chautauqua Elementary now has
all samples with arsenic below the 20 ppm cleanup level.
-
The Chautauqua Kindergarten Play Area still has one area of higher
arsenic levels (85 ppm) near the forest fringe, and some exposed CCA wood in the
sandbox.
-
The Elementary School garden, which was not sampled before, has
all samples below 20 ppm, both in the native soil and in the raised beds where
most of the flowers and vegetables are grown.
-
The garden by the district offices, used by high school students,
still has levels slightly over 20 ppm arsenic in the soil. However, the
averages are less than before.
The results are summarized in a
Technical Memorandum to the School District.
Conclusions
The School District used soil mixing as the cleanup method
in the four play areas. With soil mixing, you mix the contaminated surface soil
with cleaner soils below (or clean soil that you add) to dilute the arsenic
levels. The Vashon School District imported soil from off-island. Mixing is
still not fully proven as a means to reduce soil contamination levels, but it is
easy and inexpensive to do, and can be repeated if necessary.
Next Steps
Ecology and Public Health will
continue to work with the Vashon Island School District – providing assistance
with measures the schools can take to reduce exposure to contaminated soil.
Public Health has provided many materials that remind children to wash their
hands to remove dirt, and to take shoes off so dirt is not tracked indoors.
The Vashon School District will continue to work on reducing contaminant levels
in the district garden (used by high school students), and will use a different
play area for kindergarten students until remedial measures are complete at the
current kindergarten play area. No action is needed at the elementary
school garden, or the parking strip. More information is available from
the Vashon Island School District at
Vashon Island School District.
For further information, please contact Norm
Peck, Northwest Regional Office Site Manager, at 425-649-7047 or
nope461@ecy.wa.gov, Marian Abbett, TSP
Project Manager at 360-407-6257 or
mabb461@ecy.wa.gov, or Molly Gibbs, Public Outreach Coordinator at
360-407-6179 or mgib461@ecy.wa.gov.