IR Site 7Sediment Remediation

Presented to:WEDA 2009 Annual Meeting

Introduction

• Installation Restoration (IR) Site 7• Why is this project unique to POLB?

– Shipyard contaminants– Collaboration between DOD, regulators, POLB– Project initiated solely for purpose of remediation

Project Location

Site History

• Navy acquired beachfront and submerged lands from City of Long Beach in 1938

• Naval Shipyard opened in 1943, Naval Station opened in 1946

• LB Naval Station closed in 1994 (BRAC II); LB Naval Shipyard closed in 1997 (BRAC IV)

• In 1998, part of property reverted back to City, part is leased to Port until completion of transfer(s)

Who’s involved in this project?

• BRAC Cleanup Team (BCT)– Navy, USEPA, DTSC, RWQCB

• Port of Long Beach– Lease in Furtherance of Conveyance (LIFOC)

• Resource Agencies– USFW, CDFG, NOAA (NMFS)

• Restoration Advisory Board (RAB)• Army Corps of Engineers

Sources of Sediment Contamination and CoCs

Sources:• Process waste tanks dumped into West Basin,

including plating wastes• Storm drains• Dry dock flushing (liquid chemicals, fuels, oils, and

sand blasting materials)

Chemicals of Concern (CoCs):• Copper, lead, mercury, silver, zinc, PAHs, DDT, and

PCBs

Areas of Ecological Concern

The Process (aka, Paperwork)• 1994 – Navy starts Site 7 investigation• 1997 – Remedial Investigation Report• 2001 – Tech Memo #1• 2003 – Feasibility Study Report• 2005 – POLB/DTSC Consent Agreement• 2006 – Proposed Plan

• 2007 – Record of Decision• 2007 – Pre-Design Sampling Report• 2008 – Negative Declaration• 2009 – RD/RA Work Plan• 2009 – Bids Accepted and Award• 2010 – Dredging/Sequestration

Remedial Action Objective

To protect the presence of ecologically productive and diverse benthic communities in the sediments of IR Site 7 AOECs, consistent with existing land use.

Sediment Management Objectives

• Derived using matched data sets of chemical concentrations combined with three biological measures (the “triad” approach):

1. Amphipod survival bioassays2. Echinoderm larval development bioassays3. Benthic community structure analyses

• The lowest chemical concentration exhibiting any effects becomes the SMO

Remediation Goals (SMOs)

Chemical SMO (dry) ER-L ER-M

Copper 254 ppm 34 ppm 270 ppm

Lead 100 ppm 46.7 ppm 218 ppm

Mercury 0.9 ppm 0.15 ppm 0.71 ppm

Silver 3.5 ppm 1 ppm 3.7 ppm

Zinc 307 ppm 150 ppm 410 ppm

Total PAH 5400 ppb 4022 ppb 44,792 ppb

Total DDT 210 ppb 1.58 ppb 46.1 ppb

Total PCB 570 ppb 22.7 ppb 180 ppb

POLB Remedial Investigation

Sediment Sampling Results

AOEC Metals DetectedAbove SMOs

Depth of Contamination

Dredging Depth(+ overdredge)

A copper, lead, mercury, zinc 4 feet 4 + 2C-East none N/A 2 + 2C-West mercury, zinc 4 feet 4 + 2

STLC Sampling

• DTSC raised concerns during the CEQA review

• 6 samples from June 2007 selected for Soluble Threshold Limit Concentration (STLC) testing

• Confirmed that sediments are not hazardous waste and will not pose a risk to groundwater resources under the fill site

RD/RA Work Plan Elements

• Evaluated potential water quality impacts at the point of dredging and at the point of disposal using USACE computer models

• Evaluated expected post-dredging residual amounts and chemical concentrations

• Evaluated long-term effectiveness of the disposal location by calculating overall flux through the containment berm using the Reible model

• Developed a confirmation sampling plan to verify successful removal of the chemically impacted sediments

RD/RA Conclusions and Recommendations

• Planned remedial design is consistent with previous site investigations and satisfies ROD

• Confirmatory samples will be obtained after dredging each AOEC to determine additional sediment removal

• Residual sediments are expected to be present on the seafloor after completion but are predicted to contain chemical concentrations that are below SMOs

• Water quality impacts at the point of dredging and disposal were modeled and are predicted to be negligible at a compliance boundary of 300 feet.

Green Port Project Elements

• Local “encapsulation” of chemically-impacted sediments at Pier G Slip Fill

• Electric clamshell dredging using local grid• Silt curtains and other water quality BMPs• Particulate filters and oxidation catalysts used on all

possible diesel equipment• Tier 2 harbor craft or equivalent• Low-sulfur fuels in harbor craft• Collaboration with ACOE/Main Channel Project

THANK YOU

For more information:Christine Houston

houston@polb.com