ARCHIVED REPORTS_2014 - Laserfiche WebLink

Home Browse Search

Non-Water Release Corrective Action Plan North County Recycling Center and Sanitary Landfill CalRecycle's BMP's indicate that 1,000-year, 2 -hour storm events have occurred in California, and solid waste landfills that are Class II landfills are now required to be designed to withstand the 1,000-year, 24-hour storm event. Although the NCRCSL is a Class III landfill, CalRecycle's proposed BMP for precipitation, as a causal event, is the 1,000-year, 24-hour storm event. From the National Oceanic and Atmospheric Administration (NOAA) Atlas 14 Precipitation Maps (see Appendix C), the 1,000-year, 24-hour storm event is 5.17 inches of rainfall; which is an additional 1.31 inches of rainfall over the 100-year, 24-hour storm event. This amounts to an increase in the depth of precipitation of 34%. Previous stormwater analyses at the site have used the rational method to determine 100-year stormwater run-off for use in sizing the drainage system facilities (Preliminary Closure and Postclosure Maintenance Plan (PCPCMP) prepared by Shaw Environmental, Inc., January 7, 2010). This analysis utilized the rational method from the PCPCMP as a template to determine stormwater runoff for the 1000-year event. It has been determined that the top-deck berm, side-slope bench, and perimeter ditches have capacity to convey the run-off generated from a 1,000-year storm (see Appendix Q. However, it has been determined that 7 locations of the down-drain pipes are insufficient in capacity. It is assumed that since the bench channels have sufficient capacity, additional run-off not able to be conveyed within the downdrains would overflow onto the bench. It is anticipated that localized erosion would be realized on the bench areas due to the channel overtopping. Therefore, erosion impacts to the channels are a reasonably foreseeable casual event and, therefore, mitigation measures were evaluated as part of this NWRCAP. 4.3 Fire Impacts Fires at landfills are either subsurface fires or surface fires (wildfires). The potential for these fires to occur are dependent on the location of the landfill relative to wildfires, management of waste that is still smoldering, accidents or arson and availability of vegetation for fuel for a fire. 4.3.1 Subsurface Fires Subsurface landfill fires are most commonly caused by the intrusion of oxygen into the refuse prism from overdrawing of the gas collection system, which increases aerobic decomposition, resulting in increased temperatures. This can cause ignition of the organic material within the refuse fill. This underground combustion can cause damage to the landfill gas collection systems and potentially the intermediate and final cover. To determine if a subsurface fire exists, one must have visual confirmation or other conditions 2013.A135 I N:\San Joaquin\North County\Non-Water Release CAP\Final Report\North County_NWCAP_Report_Final.docx July 2014,Rev.0 11