Groundwater Update and Remedial Optimization Process

Overview

NAS Moffett Field Restoration Advisory Board Meeting

January 8, 2009

Alana LeeEPA Region 9

MEW / NAS Moffett Field Site – Shallow TCE Plume

Fairchild

Intel

Raytheon

NEC

SMI

Vishay/ Sumco

NASA

Navy

MEW / NAS Moffett Field Site Background

• Shallow A, A2/B1, B2, B3, C and deeper groundwater zones – contaminated with volatile organic compounds (VOCs), primarily trichloroethene (TCE)

• EPA Record of Decision - 1989• EPA Oversight – MEW Admin Order - 1990, Consent

Decree - 1992, Navy FFA Amendment - 1993• Soil cleaned up (excavation and/or soil vapor extraction)• Groundwater cleanup continues using pump and treat

systems (carbon, air strippers, slurry walls).• Current TCE in shallow groundwater

up to 40,000 ppb inside slurry walls and generally 100 to 10,000 ppb outside the slurrywalls

• Groundwater cleanup level is 5 ppb for TCE.

Soil removal and Cleanup

Fairchild and Raytheon Slurry Walls

Four underground containment walls to isolate chemicals

RAYTHEON

FAIRCHILD BLDG. 9

FAIRCHILD BLDG. 19

FAIRCHILD BLDGS. 1-4

TCE Groundwater Plume and Monitoring Wells

Groundwater cleanup is ongoing

19871992199820002001200220032004

A-Zone TCE Plume

2005

Cleanup Progress

Ten groundwater treatment systems have treated over 2.8 billion gallons of water and more than 75,000 pounds of VOCs. Soil cleaned up. More than 36,000

cubic yards of soil excavated. Five soil vapor extraction systems operated.

PRPs have spent more than $140 M on cleanup activities.

The plume has been stabilized. Groundwater concentrations have been reduced by more than 75%.

MEW

NAVY

NASA

GTE

Moffett FieldInterim remedial

cleanup measures began in 1982.

VOC Mass Removed (through 2005)Cumulative Cumulative

Groundwater VOCCompany Extracted & Treated Mass Removed

(gallons) (pounds)

Fairchild - 1 524,000,000 14,300Fairchild - 3 437,000,000 20,850Fairchild - 19 887,000,000 10,300Intel 78,000,000 2,000NEC 19,000,000 27Raytheon 282,000,000 12,900SMI 56,000,000 43Vishay 12,000,000 319RGRP S101 312,000,000 6,500

NASA 7,000,000 25Navy 232,000,000 3,200RGRP N101 549,000,000 6,500

Total 3,395,000,000 76,964

Superfund Redevelopment

Redevelopment to high profile commercial campus

began in late 1990s and continues today.

Modifications to Treatment Systems

In response to community concerns, air strippers replaced with other systems

X

Carbon Carbon

Carbon

Carbon

Oxidation

Carbon

Carbon

Carbon & Air

StrippingOxidation

2004 EPA Five-Year Review – Groundwater Recommendations and Follow-up Actions

• Develop and implement optimization plan to improve the effectiveness of the groundwater remedy at each facility and theRegional Program

• Include additional wells in sampling network to further assess contamination

• Evaluate extraction well network and pumping rates to improve capture and maintain desired gradients

• Install new extraction wells to enhance mass removal and plume capture

• Evaluate applicability of other cleanup technologies to expeditemass removal and cleanup time

Groundwater Remedy Optimization

Optimization efforts include:

• Improving the effectiveness of the remedy in protecting human health and the environment

• Improving efficiency

• Improving cost effectiveness while maintaining the same or higher level of effectiveness

• Expediting progress towards site cleanup and closure

Some Optimization Recommendations

Optimization recommendations included:

• Modification to extraction rates

• Further evaluation of alternate technologies

• Re-location/replacement of extraction wells

• Conduct treatability/pilot studies of alternative technologies

Next Steps

• Consider public input

• EPA Review Comments on Optimization reports

• Implement approved optimization recommendations in a timely manner

• Optimization efforts included in Annual Reports

• EPA Second Five-Year Review - 2009

Questions?