ARCHIVED REPORTS_XR0012911 - Laserfiche WebLink

Home Browse Search

a Mr. Chuck Carmei February 18. 1992 Page 3 During each test, the vapor flow rate (cubic feet per mixture (cfm)] and vacuum (inches H,0) were measured at the extraction well. Measurements of vacuum were also recorded from ' adjacent monitoring we11s at the station. In addition, air samples for hydrocarbons and { tetraethyl lead were taken and analyzed by GTEL Environmental Laboratories and Brown and Caldwell Laboratones, respectively. In addition, air samples were also analyzed for ; chlorinated compounds by Air Toxics, Limited. Vapor flow rates versus well vacuum data are presented in Table l and are illustrated on Figures 2, 3, 4, and 5 for ATR-2, ATR-3, ATR-4, and ATR-5, respectively. - Daring the pilot test, bag samples were collected at wells ATR-2,ATR-3,ATR-4, and ATR-5. The vapor wells were allowed to purge for at least 30 minutes before a bag sample was taken. ► In addition, testing for tetraethyl lead and chlorinated compounds was performed to determine the lead and chlorinated compound content in the subsurface soils. Results of hydrocarbon, F chlorinated compounds, and lead analysis are presented in Table 2. The pilot test was successful in extracting hydrocarbons from the soil vapors; therefore, in-situ vapor extraction is a viable method of remediating the soil beneath the site. The laboratory repotted that the samples contained •very low levels of lead [approximately 0.5 microgram (p) Iead, } corresponding to 0.016 micrograms per liter (pgll)]. Chlorinated compounds were-detected in ATR-2, but they were aL low levels and would not be expected to effect the treatment Process that will be used at the site. Laboratory reports and chola-of-custody documentation are included in Exhibit A. F i i The relatively low concentrations of total petroleum hydrocarbons (TPH) detected during the test, combined with the low TPH concentrations detected in past soil sampling, indicate that this site can be temediated in a relatively short time- Results of the vapor extraction rest indicate that soil vapor can be exmted at modcr=e-flow rates and low vacuums from exis *g monitoring wells. The radius of influence during vapor extraction was not determined due to the long distance between the tested wells. In the future, it may be necessary to install one to two additional vapor extraction wells near the ' underground storage tanks. We recommend that these wells be installed after the proposed i system is operating, if needed. i Three treatment options were considered at the site for soil remediation, including (1) carbon i adsorption. (2) catalytic oxidation, and (3) thermal oxidation. Activated carbon treatment is not recommended for sod remediation since the total petroleum hydrocarbon as gasoline(TPH-G)concentrations were high and would result in high operating costs due to the frequent replacement of activated carbon. Thermal oxi*don is not recordmended at this site because of its operating cost and high visr& ity. i i &awry and Caldweil Consultants 6"RC0PjUWd"I-0.,I_,