IDENTIFICATION AND INITIAL RECOVERY OF JET A FUEL FROM THE GROUND UNDERLYING A TANK FARM AT PALM BEACH INTERNATIONAL AIRPORT

Abstract

ABSTRACT A recent surface fuel spill incident by tank overflow at a 220,000 gal above-ground airport tank farm led to a single monitoring well installed at the request of the state. This well disclosed previously spilled Jet A fuel at the water table, 5 ft below grade. Eight monitoring wells averaging 7 ft deep were completed in 3 days, revealing a surprisingly confined pool of fuel in fine sand estimated at 24,000 ft2 but with over 30 in. of fuel in some wells. Monitoring wells 40 ft away showed a complete absence of fuel. Leaking from underground piping was tested and eliminated as a possible source. Above-ground spills, it was concluded, were insufficient as a source. Inventory records failed to show any losses. Gas chromatic analysis of the product confirmed that it was Jet A, and therefore not JP-4 from an abandoned Air Force fuel main. The source of fuel was concluded as primarily from the practice of daily fuel tank sumping to the ground, which ceased in 1974. Significantly, the spill was 10 years old and had not moved. Initial recovery was by slotted drum, later replaced by a 70 ft by 3 ft trench to the water table, gravel backfilled. Recovery of product only, without water pumping, was by an electrical chemical metering pump, continuously, at the rate of product flow to the trench, averaging 23 gal per day. Investigations of groundwater quality in nearby monitoring wells by the state agency failed to show any hydrocarbons, analyzed down to 5 parts per billion. The closest water well, 1,800 ft away, showed no contamination. Bench scale testing demonstrated that monitoring well fuel thickness overstates fuel thickness in the ground, and that trenches concentrate fuel thicknesses like monitoring wells. Tight cost control was maintained, with monitoring wells costing under $50 each, a recovery trench under $2,000, and recovery pumping under $1,000. By-product recovery revenue has offset some recovery costs.