Laserfiche WebLink
of a more detailed evaluation and more site-specific data than Tier 1 is less conservative <br /> than Tier 1, but is still conservatively protective of groundwater <br /> The third tier of the LUFT evaluation process, called Known or Suspected Groundwater <br /> Pollution of Areas with Shallow Groundwater, is the most complex of the three tiers and <br /> requires the greatest amount of site-specific data A comprehensive Tier 3 evaluation <br /> consists of running the environmental fate and transport models (SESOIL and AT123D) <br /> used to set the cleanup levels in LUFT Tiers 1 and 2. The advantages to both the property <br /> owner and the regulatory authority in using a Tier 3 LUFT evaluation, regardless of whether <br /> known or suspected groundwater pollution of areas with shallow groundwater are present, <br /> are. (1) a greater amount of site-specific data has been collected (more detailed site <br /> investigation) resulting in less uncertainty in site conditions, (2) the ability to account for <br /> multiple and different soil layers at the site (more detailed modeling input) resulting in less <br /> uncertainty in the site description, and (3) modeling runs provided in the site conditions <br /> (more detailed modeling output) resulting in less uncertainty on predicted migration <br /> Overall, the Tier 3 LUFT evaluation provides a greater degree of certainty based on <br /> extensive site data and detailed modeling that cleanup levels are protective of public health <br /> and the environment, i e , groundwater <br /> This evaluation of the site follows the Tier 3 Alternative Risk Appraisal methodology <br /> recommended in the LUFT Manual, using site-specific data to predict petroleum <br /> hydrocarbon migration <br /> G rowan-MAWAn FNL11wa5 26 93 1-6 Ch=LPukD 19" <br />