Zidell Waterfront Property Long

Northwest Region Cleanup Program
Zidell Waterfront Property
Long-Term Performance
Monitoring
Scott Manzano | Oregon Department of Environmental Quality
Historic Operation
Wood treatment facility
operating 47 years 1944 to 1991
Process wastes and
waste water discharges:
creosote, PCP, and
metals on land and in
the Willamette River
Site footprint:
• 40 acres upland soil
• 22 acres sediment
Background
• Ironworks shipyard before WWII
• Building, repair and salvage of Victory Ships
during WWII
• Purchased by Zidell in 1946: 336 ships
dismantled over 30 years – scrap sold, waste
used as site fill
• 32 acres upland + 12 acres in-water sediment
Sediment and Bankline
Contaminants
• Metals (Zn, Ni, As, Pb, Hg, Cd, Cr, Cu…)
• Chemicals –petroleum hydrocarbons, PAHs,
PCBs, Butyltins (from marine paint)
Remedy Risk Driver: PCBs
Sediment Cap Remedy selected to physically
isolate contaminated sediment from aquatic
organisms and surface water
July 1 – Oct. 31, 2011: Construction of the
Sediment Cap and Bankline Remedy
• 2,200 pilings removed (cut using hydraulic saws)
• 40,000 yards bankline soil removed/relocated
• 200,000 cubic yards of sand cap and armoring
with verification (diver collected sand cap cores)
- 2-18 feet of sand cap
- 1-3 feet of rock armoring
• Slipway Dredging and AC Reactive Core Mat
• Habitat Gravel (enhancement required by COE)
• Bio-engineered vegetated shoreline
2012 Comp. Report As Built Section
Post Remedy-Construction – DEQ
Requirements
• Upland Remedy Interim Site Management
Plan
• Sediment Cap Remedy Operations,
Maintenance, and Monitoring Plan (OMMP)
• Annual Reporting, and Five Year Reporting
– quarterly reporting until 2016
OMMP (DEQ approved June 2013)
• Physical Integrity Monitoring: maintain minimum cap
thickness and stability, identify and evaluate changes
over time
– Sediment Cap In-water Bathymetry (129 transects) and
Bankline Survey to elevation 15 COP
– Visible Inspection and Monitoring also for non-design
events (flooding, earthquake, etc.)
– Barge Launch Monitoring (pre- and post-launch)
• Chemical Monitoring for Natural Recovery
– Multi Increment Sampling (MIS) 2012, 2017…
– Breach in cap caused by non-design events
COE and COP Requirements
• Substrate Monitoring Plan, approved by NOAA
– ZERO increase in exposed rock armor (covered by
habitat gravel), other criteria, and reporting
• Bank vegetation monitoring:
– 80 % areal coverage at year 5, to be maintained
for at least 25 years (COE)
– 75 % trees and shrubs, 90 % ground cover,
inspections 2X/year and annual reports for 5 years
(COP)
Monitoring Natural Recovery
• ROD: sediment sampling on a five year
schedule for at least 10 years to:
- monitor natural recovery of low level
contamination outside the sediment cap
boundary, and
- assess potential releases associated with
breaches in the sediment cap discovered
during visual inspection
2012 Natural Recovery Monitoring
• Approved MIS plan for PCBs approved by DEQ
• Statistically valid sampling to determine the
average PCB concentration outside the cap
boundary (within an 18 acre Decision Unit
Area). 75 samples collected in 2012
• Sampling results set the baseline for future
sampling events; 2012 Baseline = 15.1 ug/kg
(17.7 lab dup)
Army Corp Substrate Monitoring
• 7 acres of habitat enhancement gravel status
• Required for the first 4 years post
construction, and again 2016 and 2021
• 12 under water video transects w/GPS
receiver; compliance points at every meter
per transect
• Compliance based on percent HG coverage
compared to baseline 2011 monitoring event