Horizontal air sparging and soil vapor extraction wells remediating jet fuel in soil and groundwater at jfk international airport, new york

摘要

Soil and groundwater at Terminal 4 (the International Arrivals Building) at JFK International Airport in Jamaica, New York, are being remediated using soil vapor extraction (SVE) and air sparging (AS). The areal extent of the contaminated soil is estimated to be 70 acres, and the volume of contaminated groundwater is estimated to be 2.3 million gallons. The remediation uses 7,000 feet of horizontal SVE (HSVE) wells and 13,000 feet of horizontal AS (HAS) wells. Based on the monthly monitoring data, approximately 47,000 lbs of volatile organic compounds (VOCs) have been removed in the extracted vapors during 18 months of operation. Approximately 96percent of the VOCs were branched alkanes and alkenes, cyclohexane and methylated cyclohexanes, while 4percent was BTEX. Approximately 352,000 lbs of petroleum hydrocarbons have been biologically oxidized in the saturated and unsaturated zones within this period. Groundwater monitoring data show a decrease in pH from 7 to as low as 4 in some areas. Nitrification was suspected for the decrease in pH. However, the levels of nitrite/nitrate after 18 months of remediation were too low to support the possibility of nitrification. Since sulfate levels had increased during the remediation, it was suspected that biological sulfur oxidation may have caused the decrease in pH. Analyses did not detect the presence of sulfur oxidizing bacteria. The decrease in pH is most likely due to the chemical oxidation of the sulfides and iron by the oxygen from the air sparging. The duration of the remediation is anticipated to be up to an additional 18 months before soil and groundwater are remediated to New York State cleanup criteria for the site.