Piers 24 & 25 Sediment Remediation Project Tacoma, Washington or… Adventures in Underpier Capping Rick Moore, Hart Crowser WEDA Pacific Chapter Conference November 5, 2009 A couple things came to mind when developing presentation: The first is how far we’ve come in 20 years on sediment cleanup projects in Commencement Bay – well north of $100M spent since the mid-1980s And secondly the challenges of underpier capping on relatively steep slopes with lots of obstructions with the added fun of trying to do the work in an intertidal zone in the Winter time. This was a Superfund cleanup project sponsored by the Port of Tacoma. Unfortunatley, Bill Evans, the Port’s project manage could not be here today to copresent the talk.

Acknowledgments Port of Tacoma US EPA US Army Corps of Engineers Washington State Department of Ecology Bergerson Construction Berger/ABAM

Presentation Overview Project Setting and Background Commencement Bay CERCLA Actions How Did We Get Here? When Will We Be Done? Remediation Elements Why Do These Projects Always Happen in the Winter? Lessons Learned The Good, the Challenged, and the Long-Term.

There are probably a number of folks here who are familiar with the general setting of sediment cleanup projects that have been going in in Commencement Bay. The Piers 24 & 25 project site is located here at the mouth of the Hylebos Waterway

Historical Tideflat Filling A little bit of background on how we got here for the current project

Commencement Bay Nearshore/ Tideflats Superfund Site Modified From Port of Tacoma Photo Slide Sitcum St. Paul Hylebos Middle Piers 24 & 25 Project Site Thea Foss 6

CERCLA Background Commencement Bay/Nearshore Tideflats Superfund Site Work Began Mid-1980s 1989 EPA Record of Decision 20+ Year Cycle to Complete Remediation Piers 24 & 25 Part of Mouth of Hylebos Remedial Action One of the Last CB/NT Remediation Efforts First provide a bit of an overview of the CERCLA background in Commencement Bay Piers 24/25 part of a lengthy CERCLA history work beginning with initial site characterization in mid-1980s, leading to EPA ROD in 1989. Part of 20+ year cycle through construction for the remedial action typical for many of the in-water projects of this complexity including Piers 24 & 25.

Site Vicinity and Project Area 2006 Aerial Photo Source: City of Tacoma Piers 24 and 25 Project Site Blair Waterway Hylebos Waterway The project site is located adjacent to land owned by the Port of Tacoma at the end of the peninsula between the Hylebos and Blair Waterways. This currently includes a seafood processing facility that uses the adjoining Pier 25 and Pier 24 for their vessels. Adjacent areas are operated by other Port tenants in the upland and by the Army Reserve at

Site Contaminants PAH, Metals, and PCB Contamination from Historical Shipyard Waste Disposal A Convenient Place to Dump Waste A Difficult Place to Clean Up

1940s Shipyard Piers 24 & 25 Project Site

1946 Aerial Photo

Piers 24 & 25 Project Timeline 1998 to 2000 Remedial Design EPA AOC 2002 and CD 2005 2000 to 2007 Revise/Finalize Design 10/07 and 2/08 Complete Construction Following completion of site characterzation for Pre-Remedial Design in the mid-1990s, project progressed to the design phase, with an AOC and CD issued in 2002 and 2005, respectively. At the same time the design went through several additional phases and EPA review cycles. Construction originally scheduled for the beginning of the in-water work window during the summer of 2007 with an anticipated 4 to 5 month duration. Startup delays and additional EPA review items eventually pushed start into October and significantly compressed the schedule to complete the work by the close of the in-water work window or “fish window” by February of 2008. Further acknolwedgement to the work team and EPA on the degree of cooperation needed to make this happen. Next time will plan for a winter start up assuming that will be delayed into the summer.

Remediation Elements Embankment Capping on 2V:1H Slopes Hot Spot Dredging for As Contamination Debris Pile Removal Hot Spot PCB Removal

A Difficult Place to Work Limited Access Forest of Pilings Steep, Slippery Rock Slopes

Barge-Mounted Placement of Capping Materials

Pier-Mounted Placement of Capping Materials

Sand Cap and Armor Rock Placement

Sand Cap and Armor Rock Placement

Toe Berm Riprap Placement

Sand Cap and Armor Rock

Lead Line Survey Control

Project Area - Post-Capping

Shotcrete Application

Photo Courtesy of the Port of Tacoma

Shotcrete Application

Piers 24 & 25 Project Area A more detailed project map shows the affected area and several features of interest….steep embankment, subtidal component, previous dredging areas, 0 elevation – keep this in mind as The remediation elements included: Embankment Capping on 2V:1H Slopes Hot Spot Dredging for As Contamination Debris Pile Removal Hot Spot PCB Removal

Debris Pile Removal

PCB Hot Spot Removal

PCB Hot Spot Removal

Lessons Learned – The Good Construction Methods Successful for Steep Slope Capping Sand Cap 400 to 700 CY/Shift Crushed Armor Rock 400 to 600 CY/Shift Shotcrete 6 to 10 CY/Shift Total Construction Cost $4.6M Within 1% of Engineering Estimate Excluding Change Orders

The Challenged PCB Hot Spot and Deeper Debris Excavation Were Unexpected and Costly Difficult Setting to Obtain Good Sampling Data 50% Toe Berm Riprap Quantity Over-Run Difficult to Estimate Riprap Repose Angle and Settling Toe Berm overrun was about $70K in rock materials Shotcrete $250K PCBs and deeper debris pile removal $250K

And The Long Term… Piers 24 & 25 Cap Performing as Intended Remediation Complete: Sitcum, Milwaukee, St. Paul, Thea Foss/Wheeler Osgood Waterways, and ASARCO Remediation Pending: OXY/Area 5106 CB/NT In Post-Construction Monitoring Portions of the Blair and St. Paul Waterways Delisted/Deleted from NPL

Thanks to WEDA Rick Moore Hart Crowser rick.moore@hartcrowser.com (206) 826-4521 Bill Evans Port of Tacoma wevans@portoftacoma.org (253) 593-4563

5106 and “OXY” In-Water Areas

Commencement Bay Waterways