Petroleum Contaminated Soil Removal_Aua Island of Tutuila_American Samoa.pdf

“Petroleum Contaminated Soil Removal, Aua Island of Tutuila, American Samoa, Formerly Used Defense Sites CON/HTRW, Project No. H09AS000704“

Background:

Aua Fuel Farm (AFF) FUDS Project No. H09AS000704, also known as Aua Village Tank Farm, consists of approximately 44 acres of land located on the northeast side of Pago Pago Harbor in Aua Village, Island of Tutuila, American Samoa. The FUDS project site is based on the former fuel farm footprint. Included within this footprint were 12 fuel tanks (approximately 55 feet in diameter and 24 feet high), 13 pump houses, and approximately 7,500 feet of 12-inch-diameter pipeline. The farm was used by the Navy for bulk fuel storage and distribution, as well as for a Construction Battalion Seabee camp to support Naval Station Tutuila during World War II.

Based on the Site Investigation Study Report dated April 1991, AFF construction was completed on 31 December 1943 and consisted of 12 bolted, steel surface aboveground storage tanks (ASTs), each with a capacity of 9,540 barrels (400,680 gallons). Twelve 500 barrel per hour fuel oil pumps were built along with the 13 pump houses and a 12-inch pipeline leading to the fuel dock. By 20 June 1945, the ASTs had been drained to the level of the output valve (12 inches from the bottom of the tank) and roughly 4,893 barrels (205,506 gallons) of fuel oil remained at the fuel farm. No records regarding the final dismantling of the ASTs have been found. Historical documents indicate that the tanks were no longer in the inventory of U.S. Naval Station, Pago Pago as of May 1947. Test pits performed in 1991 indicated that most of the fuel farm area had been re-graded and that flat areas were overlain with 5 to 10 feet of volcanic cobble and boulder of various sizes used as rock fill. As such, any tank remnants are expected to be buried under the rock fill.

By request of the American Samoa Government (ASG), USACE Honolulu District (POH) conducted multiple investigations between 1991 and 1999. During the course of those investigations, 9 of the 12 tanks were located (Tanks nos. 4–12); however, Tank No. 7 could not be found. The other three tanks (Tanks nos. 1–3) were not part of the request for investigation.

Large volumes of petroleum impacted soil were encountered during investigations at the various tank sites. Subsequently, bioremediation by oxygen pellets and thermal treatment were used at different stages to treat the contamination. All active remediation efforts ceased in 1999 with the shutdown of the bioremediation system.

In September 2018, American Samoa Power Authority (ASPA) uncovered an abandoned tank remnant at the approximate location of Tank No. 1 while installing an underground conveyance line to a residence. In a letter dated 27 September 2018, the American Samoa Environmental Protection Agency (AS-EPA) requested that POH conduct a fuel tank assessment and possible removal/remedial action at the Tank No. 1 location. On 12 November 2018, ASPA uncovered other tank remnants in the area near Tank No. 3 while installing underground utility lines.

Subsequently, AS-EPA sent a second letter to POH dated 15 November 2018 requesting that a similar assessment and removal/remediation be performed for this tank. A third letter received from the AS-EPA dated 12 February 2019 requested the same assessment and removal/remediation at a third tank discovered near former Tank No. 12. The discovery of the three tank remnants resulted in ASPA temporarily shutting down the sewer line project in Aua Village.

A Removal Design (RmD) investigation was initiated in 2019 in response to the discovered tank remnants and the AS-EPA requests. In addition to removing the remnants of three tanks, sampling was performed to delineate the nature and extent of petroleum contamination in all media (soil, groundwater, and air) within the entire fuel farm area and to assess risks posed by the contamination.

Visual observations and analytical data showed significant amounts of petroleum contamination in the soil at all twelve former tank locations, indicating widespread contamination throughout Aua Village. Remedial treatment (e.g. thermal desorption, oxygenation, bio-remedial, soil washing etc.) is the recommended action based on 1) the close proximity of the village to surface water, creating a potential ecological risk to marine habitats, 2) the high likelihood of future exposure/risk to construction workers and residents as significant subsurface/intrusive work (e.g. ASPA sewer line project) is planned in the near future, and 3) the likelihood that, even with natural attenuation, the plume will persist for decades, potentially exposing residents of the village to harmful chronic effects from petroleum contamination.

Description of Services:

The Contractor shall provide all personnel, equipment, supplies, facilities, transportation, tools, materials, supervision, and any other items with non-personal services necessary to support the contaminated soil removal, disposal, and groundwater monitoring investigations defined in the Performance Work Statement (PWS). The work required under the PWS falls under the Defense Environmental Restoration Program for Formerly Used Defense Sites (DERP-FUDS) project category of CON/HTRW without Underground Storage Tanks per USACE Engineering Regulation 200-3-1 Environmental Quality FUDS Program Policy in section 4-6.3.1. The work proposed in the PWS is being conducted pursuant to the ASAC Title 24 Chapter 1, Chapter 2 Section 24.0206, Chapter 6 subchapter F and Chapter 8.

For all response activities conducted on and off site, the Contractor shall as part of the contract and its price, be responsible for obtaining any necessary license and permits for complying with any federal, state, and municipal laws, codes, and regulations applicable to the performance of the work. All permit acquisition and requirements shall be coordinated with the Government personnel, unless specifically necessary for the operations of the Contractor.

The main tasks associated with the PWS include:

• Preparation and submission of Work Plans;

• Participate in Stakeholder meetings;

• Obtaining any necessary permits;

• Removal and disposal of petroleum contaminated soil at an appropriate disposal facility;

• Site restoration to conditions consistent with condition prior to ground disturbing activities;

• Measurement and recordation of groundwater elevation data;

• Collection and analysis of groundwater samples;

• Regular maintenance of wells and surrounding area to maintain access;

• Interpretation of groundwater chemical data;

• Prepare a Removal Action Construction Report;

• Updating the FUDSCHEM chemical database, and other technical requirements for a

FUDS CON/HTRW project.

The technical reporting shall be written from the perspective of the Army writing to stakeholders and not the Contractor writing to the Army. The Contractor shall perform to the standards described in the PWS. Optional tasks exercised at the Government’s discretion, may include, but are not limited to: sampling and analyses, consulting services in support of the AFF FUDS project and other tasks as assigned.

Period of Performance: Estimated to be one year (12 months) from date of award.

Estimated Magnitude: Between $5,000,000 and $10,000,000.

Contract Type: Firm Fixed-Priced Performance-Based contract for the services.