Nonaqueous-phase liquid characterization and post-remediation verification sampling

Light and dense nonaqueous-phase liquids (NAPLs) were identified in the surficial aquifer at the Northeast Site of the Young-Rainey Science, Technology, and Research Center located in Largo, Florida. The composition and the horizontal and vertical extent of NAPLs were determined using historical site information, analysis of ground water and soil boring data, and analysis of free product recovered from wells. Trichloroethene, dichloroethene, methylene chloride, toluene, and oils were identified as NAPLs. Calculations were conducted to determine NAPL remediation goals for both soil and ground water. Following completion of in situ thermal remediation activities at a 9,900-cubic-meter NAPL contamination area, a sampling program was implemented to verify the success of the remediation. The program consisted of using hot media sampling techniques to collect soil and ground water samples at randomly chosen locations in three sampling events during a 6- month period. Verification data indicate that the remediation was successful.