Continental Airlines Hydrant System

The Continental Airlines Hydrant Fuel System site is located at Concourse C and North Satellite of the SeaTac International Airport, SeaTac, Washington.

The Continental jet fuel hydrant distribution system at SeaTac International Airport was installed in the early 1970s and was operated by Crawford Aviation, under contract to Continental, until the fall of 1991. The inactive distribution system runs from the former underground storage tank (UST) farm on Air Cargo Road, around the North Satellite, and along the west and north sides of Concourse C. The jet fuel hydrant distribution system consists of approximately 4,110 feet of underground piping, and supplied Jet A fuel to 16 hydrant dispensing valves located along the route.

This system has been closed and capped. The Port of Seattle installed a new system (approximately parallel to the closed system), which it leases to various airlines. United Airlines acquired Continental Airlines in approximately 2010.

 ENSR Consulting and Engineering (ENSR) conducted a Site assessment in April 1994 to determine if any releases had occurred from the jet fuel hydrant distribution system. Sixty-one soil borings were advanced to 10 to 15 feet below ground surface (bgs) at 100-foot intervals along the pipeline and adjacent to high point vents, low point drains, hydrant valve pits, and hydrant line junctions. Most of the soil samples containing elevated total petroleum hydrocarbon (TPH) concentrations were collected between 5 and 10 feet bgs in borings drilled adjacent to valve pits, high point drains, and low point drains. TPH concentrations ranging from 210 to 6,100 parts per million (ppm) were found in soil samples collected from borings drilled near 10 of the 16 hydrant valve pits. TPH concentrations of 11,000 and 18,000 ppm were found near two low point drains.

The results of ENSR’s investigation showed that petroleum-impacted soil appeared to be isolated, and associated with the hydrant valve pit areas, two low point drains, and one high point vent located along the main pipeline.

Soil impacts in the vicinity of the fuel distribution system are present to a depth of approximately 20 feet bgs and have not migrated to the upper aquifer, which is located at approximately 90 feet bgs. This can likely be attributed to the shallow soil (glacial till) which impedes petroleum hydrocarbon migration due to low permeability.

An “effective alternative system” for the institutional controls was implemented by the Port of Seattle (as opposed to a Restrictive Covenant) since the property is owned by a government entity that does not routinely file with the county recording office [WAC 173-340-440 (8) (b)]. Ecology issued a No Further Action (NFA) determination on October 10, 2003 through the Voluntary Cleanup Program (VCP). The NFA determination is contingent upon the institutional controls, which restrict activities that might result in exposures to the contaminants.

A periodic review is conducted every five years following a cleanup action when institutional controls are used as part of the remedy, as required by the Model Toxics Control Act (MTCA). The purpose of the periodic review is to evaluate current site conditions and to ensure continued protection of human health and the environment.