FACT SHEET KWAJALEIN TANK FARM SITE CLEANUP

1.0 INTRODUCTION In September 2009, an aboveground storage tank (AST) located in the fuel tank farm on Kwajalein Island had an accidental release of approximately 2,065 gallons of diesel through through the bottom of the tank. Additional leaks of several thousand gallons are also suspected at two other tanks that stored JP-5 jet fuel. Older leaks from other tanks and associated piping between the 1950s and 2000s are suspected but undocumented.

Groundwater beneath the site lies at depths of about 4 feet below the ground surface; the groundwater depth varies with daily tidal fluctuations across a large portion of the site. The site is located inside the industrial area of the island; the nearest residences are almost 1 mile away. The site groundwater is not used for drinking water purposes, but small amounts of the site groundwater may be discharging into the lagoon.

2.0 CONTAMINATION NATURE AND EXTENT In February and June 2011, site investigators collected 94 soil samples and 25 groundwater samples. Notable field observations include strong odors in various soil and groundwater samples. Petroleum hydrocarbons (gasoline and diesel compounds), polycyclic aromatic hydrocarbons (PAHs), and volatile organic compounds (VOCs) were detected in soil samples at depths ranging from 3 to 10 feet below ground. Hydrocarbons were measured to be floating on top of groundwater at a maximum thickness of 0.2 feet.

Most of the shallow soils in the contaminated area outside of the spill area have lower levels of contamination than the deeper soils near the groundwater. Over time, the tidal effects on the groundwater spread the fuel over a wider area and much of the fuel is trapped in the soil.

The approximate extent of soil contamination.

Figure showing approximate locations of proposed bioslurping wells to remove the fuel

3.0 CLEANUP APPROACH The preferred cleanup approach has two phases. The first phase removes the fuel floating on the groundwater table. The second phase deals with soil and groundwater contamination after the fuel is removed. The first phase activity (fuel removal) is time-critical because it removes petroleum from the soil and groundwater and is required before the second phase can be effective. Fuel collection techniques considered and further described in the Removal Action Memorandum include infiltration galleries, dual-phase extraction, and bioslurping. Preferred techniques use methods that operate below ground, using natural tidal effects to move and flush the petroleum contamination out of the soil and groundwater. The proposed approach is to use bioslurping wells (vertical slotted piping placed underground near the top of the groundwater table) to collect fuel from the subsurface. The

recovered fuels will be measured, tested, and reused beneficially (such as incinerator fuel) if testing results allow. The Army plans to begin phase one cleanup efforts in June 2012.

Schematic of a bioslurping well and process stream. The second phase of the cleanup effort will take a longer time (several years). Cleanup techniques for the second phase will be evaluated in a Feasibility Study and bioremediation is expected to be a component of the final remedy. Bioremediation utilizes naturally occurring bacteria (fed with oxygen and nutrients) to help break down and digest the fuels. Bioremediation for soil and groundwater cleanup lessens impacts to lagoon and marine environments.

4.0 INVESTIGATIONS Supplemental sampling activities and the initial pilot testing activities are still underway at the Kwajalein Tank Farm Spill Site. The supplemental sampling results are being merged with previously collected data in the Site Investigation and Data Evaluation reports. All of the data will be used to design phase two of the cleanup effort. The Data Evaluation Report is expected to be available for public review and comment during the late summer of 2012. Human health risks are currently limited to exposure (ingestion, skin contact, etc) to subsurface contaminated soil or groundwater directly on the site. Site workers during the proposed cleanup will wear appropriate protective equipment to minimize health risks. A comprehensive risk assessment is underway for current and future site occupants. The potential impacts to the lagoon will also be investigated in 2013. Future work may include ecological risk assessments and biological sampling surveys to identify damage to the marine ecosystem.

5.0 SITE INFORMATION REPOSITORIES The Kwajalein Tank Farm Removal Action Memorandum, April 2012, is currently available for public review at the following locations:

• US Army Kwajalein Atoll Grace Sherwood Public Library (on Kwajalein)

• US Army Kwajalein Atoll Roi-Namur Library (on Roi-Namur)

• Republic of the Marshall Islands Environmental Protection Authority Office (on Majuro)

Computer users with internet access can download documents and information related to the cleanup activities at the US Army Kwajalein Atoll Cleanup website (www.usakacleanup.info). Questions about the site cleanup plan can be directed by phone to Mr. Anthony Hoover, USAKA Environmental Engineer, (808)355-5449. Written comments on the Kwajalein Tank Farm Site cleanup plan can be made one of three ways: 1) through the www.usakacleanup.info comment portal for the

Kwajalein Tank Farm RAM document, 2) emailed to comments@usakacleanup.info, or 3) mailed to Sivuniq, Inc.; Attn: Kwajalein Tank Farm RAM

Comments; APO, AP 96555. All comments must be received by May 30, 2012 .