DEQ Proposed Cleanup Request for Comments
Proposed Cleanup Action for the
Tigard Library Site
state ofOregon
COMMENTS DUE: 5 p.m., May 31
Department of
EnvironmenW
PROJECT LOCATION: 13500 SW Hall Boulevard, Tigard, OR aumitr
PROPOSAL: The Department of Environmental Quality invites public comment on its
proposed remedy for arsenic-contaminated soils at the site.
HIGHLIGHTS: Early site investigations found elevated levels of arsenic in surface and NW Region Cleanup
near-surface soils. This area of Tigard was historically used for orchards, and arsenic- Section
based chemicals were typically used as pesticides and fungicides. The City of Tigard 2020 SW 4`"Ave.
Suite 400
collected data that shows that soil erosion from upslope areas has transported soil Portland,Oregon 97201
contaminated with arsenic from the southwest portion of the site to lower elevation areas. Phone: (503)229-5614
(800)452-4011
Soils with elevated concentrations of arsenic are mostly present beneath the library Fax: (503)229-6899
building and the Pinebrook Stream corridor along the southern side of the property, and Contact: Shawn Rapp
in the original farm pond that is now used for stormwater detention. rapp.shawn@deq.state.or.us
Investigations conducted between 2002 and 2008 identified three general areas on the
Tigard library property where soil samples contained arsenic above DEQ risk-based
screening levels. These areas are the North Field, the parking and pine tree area and the
wetland/wild Area. Based on human health and ecological risk evaluations found that
these areas have arsenic concentrations that exceed one or more of the applicable risk
based concentrations for human exposure. Ecological screening values were also
exceeded in some site areas.
The selected remedies for areas of elevated arsenic involve preventing exposure through
a combination of capping, fencing, and cover vegetation. The City of Tigard will cover
the Pine tree and parking lot area with a geotextile fabric and a six-inch layer of mulch.
The city will restrict access to the wetland/wild area and north field areas by installing
fencing, and maintain vegetation cover to discourage use. If funding becomes available,
the City of Tigard may excavate contaminated soil in the north field area, replace it with
a minimum of six inches of clean fill, and re-sod with grass. The covering of the north
field area with a minimum of six inches of fill will be protective for public use, and allow
the City of Tigard to remove the fencing in the north field area. These engineering
controls will be included in a property deed restriction requiring that fences and mulch
covers are regularly inspected and maintained. The city must submit to DEQ a
contaminated media management plan if it wants to remove additional soil from the site.
DEQ must approve this plan which would outline procedures for the safe excavation,
management, and disposal of any arsenic-contaminated soil generated at the site.
HOW TO COMMENT: Send comments by 5 p.m., Tuesday, May 31, 2011 to DEQ
Project Manager Shawn Rapp Department of Environmental Quality,Northwest Region,
2020 SW 4th Avenue, Suite 400, Portland, OR 97201, e-mail to
rapp.shawngdeq.state.or.us or fax to 503-229-6899.
To review project records, contact Dawn Weinberger at 503-229-5425 and ask for
records for Environmental Cleanup Site Information (ECSI) site#4063.
DEQ will hold a public meeting to receive comments if requested by 10 or more people,
or by a group with a membership of 10 or more. View site information at
http://www.deq.state.or.us/lq/ECSI/ecsidetail.asp?seqnbr--4063
THE NEXT STEP: DEQ will consider all comments received and make a final decision
after consideration of these comments.
ACCESSIBILITY INFORMATION: DEQ is committed to accommodating people with
disabilities. Please notify DEQ of any special physical or language accommodations or if
you need information in large print, Braille or another format. To make these
arrangements, contact DEQ Communications & Outreach (503) 229-5696 or toll free in
Oregon at(800) 452-4011; fax to 503-229-6762; or e-mail to deginfbgdeq.state.or.us.
People with hearing impairments may call 711.