ARCHIVED REPORTS_2013 ANNUAL REPORT

Home Browse Search

Program R5-2010-08104 (MRP) issued April 19, 2010. This MRP supersedes the 2005 MRP (R5-2005-0829). The RWQCB issued an initial Cleanup and Abatement Order (CAO) in 1993. The 1993 the CAO directed Nestle to submit a Remedial Investigation Report (RIR)5 and a Feasibility Study (FS) report6. Nestle submitted these documents in 1994 as directed, but the RWQCB has neither approved nor rejected them'. On January 30, 2009, Nestle submitted a revised FS8 to the RWQCB, who commented on the report via a letter dated May 7, 2009. On October 16, 2009, ECM submitted the 2009 Revised FS9 addressing RWQCB's May 7, 2009 comments. Following the submittal of the 2009 Revised Feasibility Study (FS) report, the RWQCB requested additional information regarding the need for detailed evaluation of remediation technologies for all zones impacted by the presence of COCs onsite and offsite, and justification for screening out certain remediation technologies from further evaluation in the vicinity of the City of Ripon WWTP. ECM submitted the 2011 Revised FS report10 to the RWQCB on January 28, 2011 which included all components of the recommended remedial action plan and source controls. In 2012, as a component of the remedial action recommended in the 2011 Revised FS, ECM submitted a draft Water Management Plan (WMP) to the City of Ripon for review and comment. Upon review, representatives of the City of Ripon responded that the City of Ripon ordinances are consistent with the objectives of the draft WMP, but the City of Ripon declined any more formal commitment to the concepts in the draft WMP. In 2003, the RWQCB proposed revisions to the 1993 CAO. After several comments and revisions over an extended period of time, the RWQCB finalized the CAO in July 2006. Some of the requirements in the CAO have been challenged, and the State Water Resources Control Board has accepted a petition to hold the CAO in abeyance until further notification, such that the parties can reasonably negotiate the terms of the CAO. Other regulatory authorities involved with this project are the San Joaquin County Environmental Health Department, Stanislaus County Environmental Resources, San Joaquin Unified Air Pollution District, and the City of Ripon. A1.5 SOIL VAPOR INVESTIGATION Nestle investigated soil gas in 1987", 198912, 199113, and 199514 to delineate the vadose zone source and for remediation planning. The details of the investigations and remedial action taken based on the investigation results were discussed in other reports15,16,17 submitted to the RWQCB. Because soil gas investigations indicated that the highest concentrations of volatile organic compounds (VOCs), primarily TCE, in soil and groundwater were present near the Industrial and Stockton Avenue properties, ECM investigated the potential for vapor intrusion into residential, commercial and industrial buildings in 2007 and 2008 on behalf of Nestle. ECM conducted shallow soil gas surveys 18 to assess soil vapor intrusion potential in accordance with California Department of Toxic Substances Controls (DTSC) protocol. Follow-up indoor air sampling at an industrial facility located northwest of the site on Stockton Avenue verified that soil vapors presented no significant risk to human health19. ECM collected quarterly soil vapor samples at the Stockton Avenue property and at other locations west of the Site in 2008 to assess any seasonal variations of soil gas emissions from impacted groundwater 20. The data analyses did not reveal any significant seasonal variation.