07.07.2009 - Breemer Dennis Koellermeier
From: Chris W. Breemer [cbreemer@geoengineers.com]
Sent: Tuesday, July 07, 2009 9:21 PM
To: Dennis Koellermeier
Subject: FW: Tigard Library Focused Feasibility Study- DEQ Comments
Dennis,
Loren's e-mail below is good news! There is finally light at the end of the Tigard Library arsenic tunnel.
I believe you are on vacation. I will call you when you return so that we can discuss wrapping up this project.
I hope you had a good Independence Day holiday.
Regards,
Chris
Chris Breemer, R.G., L.G.
Senior Project Manager I GeoEngineers
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From: GARNER Loren [mailto:GARNER.Loren @deq.state.or.us]
Sent: Tuesday, July 07, 2009 2:33 PM
To: Dennis Koellermeier
Cc: Chris W. Breemer; Greer Gaston; SEIDEL Paul; GILLES Bruce A
Subject: Tigard Library Focused Feasibility Study - DEQ Comments
Dennis,
We have reviewed the Revised Focused Feasibility Study for the Tigard Library property, dated June 15, 2009.
This submittal is accepted as written, and approved with the following comments and considerations.
General Comments:
1. The selection of the final remedy is an integral part of the No Further Action determination (NFA)for the site. There
process of listing this facility on the Confirmed Release List. All three of these activities have public notice requireme
action for final review and approval.
2. The next immediate step is for DEQ to draft a Staff Memo summarizing the site information and decisions, with our fi
anticipated timing for this action is to complete the memo before August 15, when we anticipate being able to subm
Dennis Koellermeier
From: GARNER Loren [GARNER.Loren @deq.state.or.us]
Sent: Tuesday, July 07, 2009 2:33 PM
To: Dennis Koellermeier
Cc: Chris W. Breemer; Greer Gaston; SEIDEL Paul; GILLES Bruce A
Subject: Tigard Library Focused Feasibility Study- DEQ Comments
Dennis,
We have reviewed the Revised Focused Feasibility Study for the Tigard Library property, dated June 15, 2009.
This submittal is accepted as written, and approved with the following comments and considerations.
General Comments:
1. The selection of the final remedy is an integral part of the No Further Action determination (NFA)for the site.
There is also the need to complete the process of listing this facility on the Confirmed Release List. All three of
these activities have public notice requirements that can be combined into one action for final review and
approval.
2. The next immediate step is for DEQ to draft a Staff Memo summarizing the site information and decisions,with
our final recommendation. The anticipated timing for this action is to complete the memo before August 15,
when we anticipate being able to submit the public notice to the Secretary of State Bulletin for a public
comment period of September 1-30, 2009. If there are not significant issues identified during public comments,
the final NFA is likely to be issued in October 2009.
Specific Comments:
3. We concur with the conclusions in the Human Health and Ecological risk assessments, as summarized in Section
2.4.6. We accept the default background concentration of 7 mg/kg arsenic as the risk-based concentration
(RBC)for protection of adult and child park users.
4. We concur with your evaluation and selection of alternatives, including the implementation of Alternatives 2
and 4 in the North Field area as funds become available.
5. Section 5.2.2.3—Institutional controls will be required for this site. An Easement and Equitable Servitudes
document will be prepared (initial draft by DEQ),signed by the City and DEQ, and recorded with the County to
permanently document the environmental conditions at the site and the necessary actions to maintain the site
in a safe manner. There will also be a need for one comprehensive Management Plan for the site that
incorporates documentation of site conditions and performance expectations, maintenance and monitoring
needs, and a basic contaminated media management plan (initial draft by the City). These documents can be
developed concurrently with the steps toward issuance of the NFA. Work may begin on the Management Plan,
and should be coordinated with DEQ as it progresses.
6. Section 6.1—For the Parking Area and Pine Tree Area,the existing demarcation fabric and mulch can be
augmented or replaced, as the City prefers, to provide the final demarcation layer with 6 inches of bark or mulch
above it. The thickness can be tapered around the base of the trees to maintain healthy conditions for the
trees. The soil around the edges of pathways or parking may be removed to provide at least 4 inches of cover,
and tapered to the full 6 inches of thickness within 2 feet of the edges.
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7. Section 6.2—For the wetland areas near the Pinebrook Stream and pond,the existing conditions are adequate
to protect against unacceptable human exposure. This includes the small area at the corner of Wall Street and
Hall Blvd, and the area next to the bridge where contaminated fill may have been placed. The existing fences
must be maintained, but additional fencing will not be required if the vegetation and/or mulch layer are
maintained similar to current conditions. This also applies for the Wild Area to the north. The observation area
is acceptable as is, and additional fencing is not needed if vegetation is maintained. There was a small trail
observed at our last visit on June 24th extending from the observation area toward the creek oxbow, but it is
overgrown and soils are not appreciably exposed. Should future trails become more established,vegetation
should be modified to disrupt the pathways and prevent areas of open exposed soil.
8. Section 6.3—For the North Field Area,only the areas above the RBC of 7 mg/kg arsenic need to have access
limited or the surface soils replaced. At present, much more of the field is maintained in a tall, uninviting
manner than is necessary. If the removal and replacement option is selected under Alternative 4, a layer of 6
inches of clean soil maintained with turf grass will be adequate protection for the intended uses of this area.
We understand that the floodplain nature of this area may preclude net filling, but the environmental concerns
can be adequately addressed through either capping or excavation and replacement. The current fence and tall
vegetation in the impacted area will be adequate protections for up to two years(through 2011) while awaiting
funds or grants to implement Alternative 4 excavation and replacement. The seasonal rough mowing of the
area for fire protection is acceptable. If the Alternative 2 access restrictions appear to be the solution for longer
than two years,the addition of the split-rail fence around the rest of this area is recommended.
We look forward to seeing this project through to completion. Please let me know of any questions.
Loren
Loren G. Garner, P.E.
Senior Project Engineer, DEQ Northwest Region
Environmental Cleanup & Emergency Response Section
2020 SW 4th Avenue, Suite 400
Portland, OR 97201
503-229-6900
Fax 503-229-6954
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