Laserfiche WebLink
VED7.0 DETERMINATION OF TIME TO WATERS OF THE U. ,# I <br />FEB 2 5 2016 <br />ENVIRONMENTAL <br />NFA! T4 RFPARTMFNT <br />7.1 TIME TO WATERS OF THE U.S. METHODOLOGY <br />For a terminal with vertical Time to Groundwater with less than 5 days <br />and which is located in an area where groundwater is potentially <br />hydraulically connected to Waters of the U.S., ERM uses analytic element <br />and fate & transport models to estimate the horizontal Time to potential <br />Water of the U.S. The results from the GIS and Watershed Modeling <br />System (reference Section 5.0) and from Determination of Groundwater <br />Hydraulically Connected to potential Water of the U.S. (reference Section <br />6.0) are used in the groundwater modeling. The analysis and results are <br />included in Appendix B. <br />7.2 TIME TO WATERS OF THE U.S. RESULTS <br />The Time to Waters of the U.S. is calculated to be 38 years. This analysis <br />estimates a time period of 72 hours as a conservative approximation of the <br />amount of time to discover a release. This number is considered the <br />longest time to discover a release based on the time between tank yard <br />inspections given the terminal's current operations. The terminal has a <br />Facility Response Plan (FRP) in compliance with 40 CFR 112.20 including <br />40 CFR 112 Appendix E Determining Response Resources Required for <br />the Worst Case Discharge to the Maximum Extent Practicable. This <br />terminal's FRP describes that response will be mobilized within 1 hour of <br />the spill discovery. The FRP Appendix B - Contractor Response <br />Equipment and Figure 7.1-1 detail the specific manpower and response <br />equipment that will be mobilized at the site in accordance with a Tier <br />rating, which is up to Tier 3 for worst case discharge for this terminal, for <br />response capability. Given the calculated estimated Time to Groundwater <br />of < 1 day with a Time to Waters of the U.S. of 38 years, and based on <br />engineering judgment which includes the implementation of the Facility <br />Response Plan (FRP) and the site's commitment to manpower and <br />response equipment, ERM concludes that the containment at this facility is <br />sufficiently impervious. <br />ERM 7-1 110870\CHEVRON\SPCC -JULY 2010 <br />