ARCHIVED REPORTS_XR0003149 - Laserfiche WebLink

Home Browse Search

1 i, CHECKLIST OF REQUIRED DATA FOR NO FURTHER ACTION REQUESTS AT UNDERGROUND TANK SITES ' Re orts/mfonnation Continued (continued) Quarterly Groundwater Monitoring Reports—Krazan Groundwater Monitoring and Sampling Reports, March 17, 1999,June 30, 1999,November 15, 1999,and February 22, 2000 Semi-Annual Groundwater Monitoring Reports--Klemfelder Additional Subsurface Assessment Sensitive Receptor Survey and Groundwater Monitoring and Sampling Report, October 16, 2000, Groundwater Sampling Reports, Apn12,2001,January 23,2002,and August 22,2002 ' Semi-Annual Groundwater Monitoring Reports--Ground Zero Analysis, Inc Groundwater Monitoring and Sampling Reports, March 5, 2004 and July 30, 2004, Additional Subsurface Investigation and Groundwater Monitoring and Sampling Report,May 23,2005 ' Other reports--Ground Zero Analysis, Inc Workplan for Additional Subsurface Investigation dated September 2, 2004 11 Best available technology(BAT)used Soil Excavation and Natural Attenuation ' 12 Reason wh background was unattainable usina BAT Background not attained to date, however natural attenuation will reduce concentrations to background in the future The very low levels of residual soil and groundwater contamination do not pose a threat human health or the environment and, therefore, ' additional expenditures are not warranted rl'd 13 Mass balance of treated versus remaining contaminants The remaining volume of contaminated soil is estimated at a maximum of approximately 2,800 cubic yards, containing an estimated 6 pounds of ' benzene and 185 pounds of gasoline We have estimated, based on the most recent analytical results that approximately 0 7 pounds of benzene and gasoline remain in the groundwater A copy of the residual soil and groundwater contaminant mass calculation sheet is included in Attachment 4 1 14 Assumptions, _parameters, calculations, and model used in risk assessment and fate and transport ' modeling Attachment 5 contains contaminant transport modeling data and results Modeling indicates that groundwater contamination above the state MCL will not leave the property I 15 Rationale why conditions remaining at site will not adversely impact water quality, health, or other beneficial uses Dissolved benzene at concentrations above the MCL is present in groundwater ' beneath the site However, groundwater beneath the site is not used, benzene concentrations are decreasing with time, transport modeling indicates that offsite plume migration will not occur, residual contaminant levels in soil are minor and are not expected to provide any significant source of continued groundwater degradation 16 WET or TCLP results Not applicable/not analyzed f i I I