US Army Fort Lewis I5 Corridor

Last updated April 9, 2018

Two reports are now available. The Draft 2017 Annual Air Sparge and Soil Vapor Extraction System Performance Monitoring Report documents the operation, maintenance, and monitoring for systems that address petroleum contamination and protect indoor air quality in the credit union building. The 2017 Comprehensive Land Use Controls report describes JBLM’s land use controls at restored cleanup sites. Land use controls restrict use, access, or construction at these sites. 

Contamination was from a 300 gallon underground storage tank used to store heating oil. The tank and surrounding soil contaminated with petroleum hydrocarbons were removed in 1996. JBLM has conducted 16 monitoring groundwater at the site using a total of 8 monitoring wells since 2005. 

This site has two areas called Miller Hill area and Former Skeet Range. From World War I to the 1960s the Miller Hill area was used for small arms training ranges. Decades of spent bullet slugs and fragments have accumulated in the soil and contaminated it with lead.
 
The former skeet range was used in the 1960s and 1970s. Both sites have high lead levels in soil.

JBLM environmental staff identified contamination at these two sites.
 
Soils are contaminated with:

• Petroleum hydrocarbons
• Volatile organic compounds (VOCs)
• Lead

The sources of lead are former small arms shooting ranges in the Miller Hill area and a skeet target range are the sources of the lead. JBLM has already conducted testing in these areas and proposes to clean them up by removing and stabilizing lead contaminated soil.

Ecology works to clean up contaminated properties throughout the state. There are several steps in the cleanup process.

A Remedial Investigation (RI) is an in-depth study to:

• Determine site features such as groundwater flow, sediment type, and other factors.
• Define the type and extent of contamination.
• Assess potential effects on human health and the environment.
• Establish cleanup criteria.

A Feasibility Study (FS):

• Establishes cleanup criteria.
• Evaluates cleanup alternatives.
• Evaluates cost estimates of cleanup alternatives.

A Cleanup Action Plan CAP:

• Describes the selected cleanup methods.
• States cleanup standards and other requirements.

Interim Action Plan
In 2012, Ecology approved an Interim Action Work Plan. This plan cleaned up contamination before finalizing the cleanup process. It addressed lead contaminated soils. Cleanup actions included:

• Digging up and stockpiling contaminated soils at the base of Miller Hill.
• Treat highly contaminated soil.
• Haul contaminated soil to active firing ranges for reuse as backstops and berms to catch bullets.
• Leave contaminated soil in the steepest parts of Miller Hill.
• Fence off contaminated areas.
• Replant area with grasses and Oregon White Oaks.

Area of Concern 8-4 meets cleanup levels
In 2017, Ecology agreed with Joint Base Lewis McChord (JBLM) that they can stop monitoring the groundwater at an area that was contaminated with petroleum hydrocarbons. This area, called AOC 8-4, has met the cleanup level for the past 4 semi-annual monitoring events.
 
Ecology also requested that JBLM:

• Maintain the function and the integrity of the monitoring wells. 
• Visually inspect the monitoring wells at this site once per year. 
• Provide a narrative account of the inspections in the groundwater monitoring report for other areas of concern that they submit to Ecology annually.

Ecology may request JBLM to sample the wells at this site at a later date to confirm the groundwater is in compliance with MTCA cleanup levels.