3.0 Affected Environment - Knik Arm Bridge and Toll Authority

Knik Arm Crossing DraftFinal EIS
Affected Environment
Site OT92 – Abandoned Hydrant Lines – Medium Impact
This site consists of former hydrant fuel lines associated with operations at Elmendorf (see
Figure 4.21). No comprehensive investigations have occurred to date, but investigations are
planned for 2007. The planned closure date is October 31, 2010 (USAF 2001). The primary
concern with this site is the potential for undocumented petroleum hydrocarbon impacts from
past leaks. This site was assessed as having a medium-impact risk to the project based on the
possibility of petroleum contamination migrating from the site to the project search corridors.
Site PL81 – POL Pipelines 81 – High Impact
Site PL81, a CERCLA NPL site, crosses the Anchorage approach alternatives and is the site
of abandoned POL lines that began at the POA fuel distribution system and terminated north
of the east/west runway on Elmendorf (see Figure 4.21). The 10-inch jet fuel and aviation gas
pipelines were damaged in the 1964 earthquake and abandoned shortly thereafter. To address
the remaining soil and groundwater contamination at the site, an environmental Cleanup
Plan 2005 was developed in cooperation with the ADEC to remove contaminated soil
(ADEC 2005a). Additional excavations are planned for the area. PL81 could affect the
project if contaminated soil were found to exist within the proposed project search corridors.
This site was assessed as having a high-impact risk to the project because of known fuel
contamination associated with the line and because the alignment would directly cross the
site.
Site SD52 – Cherry Hill Ditch/Ravine – Medium Impact
Elmendorf site SD52, also known as the Cherry Hill Ditch or Ravine, would be crossed by
both the proposed Erickson and Degan Alternatives north of the proposed cut-and-cover
tunnel (see Figure 4.21). SD52 is a CERCLA site and, in 1994, low levels of polychlorinated
biphenyls (PCBs) were capped in the ditch. The ditch begins on Elmendorf and crosses
perpendicular to the ROW corridor before reaching its terminus at the POA. The drainage
ditch receives stormwater drainage from under the runway and possibly from shop drains on
Base. Hydrocarbons, solvents, oils, and detergents are present. All contaminants have been
dealt with to the extent practicable, and no further remedial action is required or planned
(NFRAP 29 ) (ADEC 2005a). However, an NFRAP does not indicate that the site contaminants
have been removed, only that the regulating agencies require no additional cleanup based on
existing land use. Impacts on the area during construction would require management of
contaminated soils. Additionally, if controlled-access ROW were acquired through the area,
the new property owner might be exposed to future environmental liability issues, depending
on the agreements made with the responsible party. This site was assessed as having a
medium-impact risk to the project because the alignment would directly affect the site and
because there is the possibility that residual contamination exists.
29 NFRAP, or “No Further Remedial Action Planned” sites, are sites that have been removed from the
CERCLIS list by USEPA. These sites are no longer considered a federal concern. Suspected hazardous waste
sites throughout the United States are listed in the Comprehensive Environmental Response, Compensation
and Liability Information System, or CERCLIS. This federal database contains information on preliminary
assessments, potential and actual hazardous waste sites, site inspections, and cleanup activities. CERCLIS
sites are candidates for addition to the federal and state Superfund lists.
3-126 12/18/07