NMCB Building Area T-1416, Expanded Area

Background
The Naval Marine Construction Battalion (NMCB) Building Area site is located on the northern shore of Sweeper Cove. This site was used primarily for industrial purposes until the late 1990s. Two of the four buildings remain at the site. Three abandoned underground fuel transfer pipelines cross the site. Investigations at the site began in 1993. Free product was found, and petroleum hydrocarbons in groundwater exceeded state cleanup criteria. Free-product recovery was conducted at the NMCB Building Area site intermittently from September 1997 through July 2005.

The OU A Record of Decision (ROD) identified free-product recovery as the interim remedy for this site in 2000. As of July 2005, free-product recovery in existing wells met the established endpoint specified in the OU A ROD. A Decision Document was prepared according to State of Alaska regulations in 2006. Institutional controls (ICs), free-product recovery (in new wells), and monitored natural attenuation (MNA) for groundwater were selected as the final remedy.

Identified Contaminants
Petroleum hydrocarbons in soil and groundwater

Click here to display the data table.

Current Actions
The Navy conducts ICs inspection, passive product recovery, monitoring for product thickness in 17 wells, and natural attenuation monitoring in 9 wells annually.

Petroleum Institutional Controls

Equitable Servitude

Groundwater Restrictions
Domestic use of groundwater in the Downtown Area is restricted because of the potential presence of petroleum compounds and other chemicals in the groundwater. Domestic groundwater use is defined as that used by households or transients for human and animal consumption, cooking, bathing, showering, gardening, irrigation, or use on consumable food products, watering animals and any other domestic use. The excavation notification program at individual sites provides one barrier to drilling; enforcement of the prohibition will also occur through periodic visual inspections. The visual inspections will focus on unauthorized wells in the restricted area. Groundwater use restrictions are included in the equitable servitude.

Inspections and Reporting
The ICs identified in this plan will be inspected and reported on an annual basis, or as necessary. Annual site inspection reports will present the results of inspections. The annual reporting requirements will be included in CERCLA 5-year reviews.

Land Use Restrictions
Commercial and industrial land uses and continuing residential land uses where housing exists in the Downtown Area are permitted in accordance with the Interim Conveyance document. Residential housing is allowed in existing housing units located at Amulet Housing, Arctic Acres Housing and SWMU 62. Future residential housing construction will be evaluated for impacts to ongoing petroleum cleanup activities.

Soil Excavation Restrictions
Soil excavation notifications are required for all the Downtown Area Petroleum sites with ICs. The excavation notifications will be required for each proposed excavation below 2 feet. The notifications will be evaluated to determine whether a proposed project at an IC site is consistent with the land use restrictions. The notifications are an additional tool for the Navy to receive timely information (in the absence of local zoning requirements) to monitor land use restrictions.

Petroleum Engineering Controls

Fencing and Gates

Land Use Control and Ordnance Hazard Signs

Other Engineering Controls
Other engineering controls include landfill caps (CERCLA sites), free-product recovery wells (SAERA sites), and free-product recovery trenches (SAERA sites).

nmcb survey