09.04.2008 - Koellermeier s
s " City of Tigard
Memorandum
To: Staff of the Tigard Public Library
From: Public Works Director Dennis Koellermeier
Re: Important Information on Arsenic and the Library Public Library Grounds
Date: September 4, 2008
Several areas around the library have soil containing concentrations of arsenic that exceed EPA
recommended levels for humans. Arsenic is considered a potential carcinogen.
Common public areas, like the gazebo, picnic tables near the drive-thru book drop, library
courtyard, and interpretive viewing platform, are not located in arsenic contaminated areas. A map
showing the areas containing elevated levels of arsenic is attached to this memo.
A Human Health Risk Assessment and Level I and Level II Ecological Risk Assessments report
was recently finalized and accepted by the Department of Environmental Quality (DEQ. The City
has been working with various consultants and the DEQ to determine the extent and severity of the
contamination. This information is contained the report. A copy of the report is available for your
review.
A press release on the arsenic contamination will be issued next week, but I wanted the library staff
to be appraised of the situation and the City's actions as soon as possible.
How did the arsenic get here?
The contamination likely came from arsenic-laden pesticides or herbicides. These were applied to
orchards that were historically present to the west of the library site. The arsenic was carried in
surface water run off and was ultimately deposited on the low-lying library property.
Who's at risk?
For library employees, maintenance workers, landscapers and excavation workers, arsenic
concentrations in the soil are within DEQ standards. However, in the scenario of a patron (adults
and children) who visited the library grounds on a weekly basis, the estimated risk would exceed
DEQ standards. The City continues to work with DEQ to determine the best way to reduce this
risk.
How does exposure occur and how can I avoid it?
Exposure to arsenic in soil occurs by way of direct contact, ingestion, and inhalation. To avoid
exposure, don't eat, breathe or touch contaminated soil.
What's next?
The City has received permission from DEQ to temporarily install a split rail fence in the field to
the north of the library. It will serve as a barrier between the outdoor areas where most organized
public events take place (library patio, soft trail and gazebo) and the contaminated area in the center
of the open field. "No entry" signs will be posted on or near the fence.
The City is working with and awaiting direction from DEQ regarding what permanent measures are
needed to address the contaminated soil. Options include removal of contaminated soil, covering
contaminated soil to prevent exposure, and institutional controls such as fencing or restricted
access.
Questions?
Please feel free to contact me at 503.718.2596 or dennisntigard-or.gov.