Approval Letters and Communications

Type Download Document Name Publish Date Size
Click to Download DOI and DTSC Joint Agency Directives on Topock Groundwater Remediation Project Model Revisions October 4, 2016 146.47 KB
Click to Download DOI and USFWS Review of Protective Measures for Bat July 12, 2016 40.67 KB
Click to Download DOI/DTSC's Reponse to Support of Monitoring Well MW-U installation in Interstate 40 median for the PG&E Topock Compressor Station, Needles, California December 22, 2015 4.49 MB
Click to Download ARCADIS Response to Fort Mojave Indian Tribe Comments on the Final Design Directives on Topock Groundwater Remediation Project December 4, 2015 30.1 KB
Click to Download Chemehuevi Tribe response to the October 19, 2015, Final Design Directive to PG&E on Modeling Follow-up for Topock Groundwater Remediation Project December 2, 2015 560.21 KB
Click to Download Fort Mojave Tribe response to the October 19, 2015, Final Design Directive to PG&E on Modeling Follow-up for Topock Groundwater Remediation Project November 20, 2015 92.28 KB
Click to Download DTSC: PG&E's Clarification on on October 19, 2015 Direction Letter for Final Design November 5, 2015 83.52 KB
Click to Download PG&E's Request for extension to submit the cost estimate appendix on or before December 4, 2015 November 4, 2015 65.46 KB
Click to Download Final Design Directives on Topock Groundwater Remediation Project October 19, 2015 900.1 KB
Click to Download ADEQ Response to Review of Arizona Monitoring Wells November - December 2014 Groundwater Sampling Results, Topock Groundwater Site, Needles, California June 29, 2015 130.88 KB
Click to Download Proposal for IM3 Extraction Well Pumping Rate Modifications, PG&E Topock Compressor Station, Needles, California May 28, 2015 88.2 KB
Click to Download Results of PG&E December 2014 and March 2015 sampling of the Moabi Regional Park Wells (PM-03 and PM-04) April 16, 2015 181.05 KB
Click to Download PG&E Topock Compressor Station Remediation Site – DOI Comments on the Draft Basis of Design Report/Intermediate (60%) Design for the Final Groundwater Remedy, PG&E Topock Compressor Station, Needles, California March 31, 2015 51.64 KB
Click to Download Review of Arizona Monitoring Wells November-December 2014 Groundwater Sampling Results, Topock Groundwater Site, Needles, California March 23, 2015 279.72 KB
Click to Download DOI and Water Board confirmation of CMP Report Changes/Reduction March 20, 2015 102.75 KB
Click to Download Comment Resolution Process for the Basis of Design Report/Pre-final (90%) Design Package for the Groundwater Remedy, Pacific Gas and Electric Company (PG&E), Topock Compressor Station, Needles, California February 23, 2015 365.13 KB
Click to Download United States Department of the Interior and California Department of Toxic Substances Control Directives on Outstanding issues on the Basis of Design Report/Pre-Final Design (90% Design) Supplemental Package for PG&E Topock Compressor Station Remediation December 23, 2014 5.52 MB
Click to Download DTSC and DOI Directives on Incomplete Elements Identified in the Pre-Final (90%) Basis of Design Report and Construction/Remediation Action Work Plan for the Groundwater Remediation Project at the Pacific Gas and Electric Company (PG&E), Topock Compressor October 21, 2014 195.96 KB
Click to Download DTSC and DOI Email to PG&E: Incomplete Pre-final Groundwater Remedy Design Elements October 21, 2014 163.52 KB
Click to Download Hualapai Letter to DTSC an d DOI: October 7, 2014 Letter to Pacific Gas & Electric Groundwater Remedy Infrastructure Site Verification Field Work October 8, 2014 444.4 KB
Click to Download DTSC Response to Section 7 of the 2013 Annual report Recommendations June 27, 2014 272.98 KB
Click to Download DTSC response regarding the Addendum to RCRA Facility Investigation/Remedial Investigation Report, Volume I - Site History and Background, PG&E Topock Compressor Station, Needles, California (EPA ID No. CAT080011729) June 4, 2014 34.66 KB
Click to Download DTSC Approval of Extension for Review of Draft Risk Assessment Work Plan Addendum II, PG&E Topock Compressor Station, Needles, California June 2, 2014 190.83 KB
Click to Download Request for Information Regarding Historic PG&E Wells, Topock Compressor Station, Needles, California May 22, 2014 571.06 KB
Click to Download DTSC Response to Inquiry Regarding Hyperaccumulative Plants at the Pacific Gas and Electric Company (PG&E), Topock Compressor Station, Needles, California (EPA ID No. CAT080011729) April 30, 2014 1.49 MB
Click to Download DTSC and DOI Directives on Outstanding Issues of the Response to Basis of Design Report/ Intermediate (60%) Design Comments for PG&E Topock Compressor Station Remediation Site April 4, 2014 115.14 KB
Click to Download California Water Board Letter: Topock Compressor Station: Remedy Requirements Associated with Injection Groundwater Containing Naturally Occurring Arsenic, PG&E Topock Compressor Station, Needles, California November 20, 2013 246.24 KB
Click to Download DTSC Direction on Freshwater Implementation Activities (via email), PG&E Topock Compressor Station, Needles, California November 6, 2013 51.57 KB
Click to Download PG&E Letter: Cumulative Project Update (2010-2012) for Field Work Performed in Accordance with the Programmatic Biological Assessment for the Pacific Gas and Electric Company Topock Compressor Station October 11, 2013 115.31 KB
Click to Download DTSC letter on Bird Impact Avoidance and Minimization Plan Topock Groundwater Remediation Project, PG&E Topock Compressor Station, Needles, California October 1, 2013 400.77 KB
Click to Download Resolution of the California Department of Toxic Substances Control Adopting an Addendum to the Final Environmental Impact Report Prepared for the Topock Compressor Station Groundwater Remediation Project, Needles, California September 4, 2013 12.82 MB
Click to Download Resolution of the California Department of Toxic Substances Control Approving the Final Implementation Plan for Evaluation of Alternative Freshwater Sources for the Topock Compressor Station Groundwater Remediation Project, Needles, California September 4, 2013 45.09 KB
Click to Download Comment on 60% design extended until 8/8/2013, RFI/RI Vol 1 Addendum until 9/9/13, PG&E Topock Compressor Station, Needles, California June 21, 2013 21.11 KB
Click to Download DOI Response to the Second Part of Freshwater Evaluation Implementation Plan response to comment meeting June 3, 2013 69.96 KB
Click to Download Timing for Submittal of First Quarter GMP-PMR report, PG&E Topock Compressor Station, Needles, California April 30, 2013 100.89 KB
Click to Download Repairing Wells in Accordance with California Well Standards at Pacific Gas and Electric Company (PG&E), Topock Compressor Station, Needles, California, (EPA ID No. CAT080011729) January 28, 2013 1.1 MB
Click to Download Request for Second Extension of Groundwater Remedy 60% Design Submittal, PG&E Topock Compressor Station, Needles, California November 30, 2012 197.72 KB
Click to Download Request for Modification of Deadline/Format -- PG&E Biennial Performance Assessment Report for the Injection Wellfield November 29, 2012 113.34 KB
Click to Download DTSC Letter to the California Regional Water Quality Control Board Re: Proposed Injection of Groundwater with Arsenic Concentration Above Maximum Contaminant Level at Pacific Gas and Electric Company (PG&E), Topock Compressor Station, Needles, California August 8, 2012 56.57 KB
Click to Download DOI Approval of Revised Groundwater Corrective Measure Implementation/Remedial Design Work Plan for SWMU 1/AOC 1 and AOC 10, PG&E Topock Compressor Station, Needles, California November 3, 2011 84.75 KB
Click to Download Approval of Revised Addendum to Revised Work Plan for East Ravine GW Investigation; Final Rev. Implementation Plan for Repair of Monitoring Wells MW-38S and MW-38D and Old Well/Pipe Reconnaissance at PG&E, Topock Compressor Station, Needles, California February 24, 2011 828.31 KB
Click to Download Topock GMP Monitoring Frequency Modification, PG&E Topock Compressor Station, Needles, California March 3, 2010 88.2 KB
Click to Download Groundwater Characterization Requirements for the East Ravine and Compressor Station Areas, PG&E Topock Compressor Station, Needles, California February 24, 2010 86.69 KB
Click to Download DTSC Approval of Final Groundwater Corrective Measure Study/Feasibility Study Report for SWMU 1/AOC 1 and AOC 10, PG&E, Topock Compressor Station, Needles, California (EPA ID NO. CAT080011729) December 18, 2009 151.33 KB
Click to Download Final Groundwater Corrective Measures Study/Feasibility Study Report for SWMU 1/AOC 1 and AOC 10, PG&E Topock Compressor Station, Needles, California December 17, 2009 151.33 KB
Click to Download DTSC Letter: Acceptance of Final Groundwater Risk Assessment Report, PG&E Topock Compressor Station, Needles, California December 10, 2009 60.54 KB
Click to Download DTSC Letter: Clarification of Specific California Applicable or Relevant and Appropriate Requirements, PG&E Topock Compressor Station, Needles, California October 6, 2009 1.35 MB
Click to Download DTSC Letter: Conditional Approval of Modifications to the Compliance Monitoring Program, PG&E Topock Compressor Station, Needles, California September 3, 2009 94.33 KB
Click to Download DTSC Conditional Approval of RFI/RI Volume 2 Addendum May 28, 2009 31.64 KB
Click to Download Approval of Proposal for Consolidating Reporting for the Topock Interim Measures Performance Monitoring Program with Site-wide Groundwater Monitoring Program, PG&E Topock Compressor Station, Needles, California May 26, 2009 25.51 KB
Click to Download Approval Letter for the Revised Final RCRA Facility Investigation/Remedial Investigation (RFI/RI), PG&E Topock Compressor Station, Needles, California - Hydrogeologic Characterization and Results of Groundwater and Surface Water Investigation February 4, 2009 42.64 KB
Click to Download Additional Direction on Preparation of the Corrective Measure Study/Feasibility Study at PG&E, Topock Compressor Station, Needles, California (EPA ID NO. CA080011729) December 8, 2008 341.83 KB
Click to Download Clarification of Direction on Preparation of the Corrective Measure Study/Feasibility Study at PG&E Topock Compressor Station, Needles, California November 6, 2008 314.12 KB
Click to Download Change in River Monitoring Program to Include Collection and Analysis of Unfiltered Surface Water Samples at PG&E, Topock Compressor Station, Needles, California (EPA ID NO. CAT080011729) October 30, 2008 38.33 KB
Click to Download Revision of Monitoring and Reporting Program (MRP), Board Order No. R7-2006-0060, PG&E Topock Compressor Station, Needles, California August 28, 2008 182.18 KB
Click to Download Approved Modifications to the Topock IM Performance Monitoring Program, PG&E Topock Compressor Station, Needles, California August 4, 2008 182.18 KB
Click to Download Modification to Surface Water Monitoring Program at PG&E Topock Compressor Station, Needles, California July 28, 2008 234.84 KB
Click to Download Conditional Approval of the Revised East Ravine Work Plan at PG&E Topock Compressor Station, Needles, California July 24, 2008 35.58 KB
Click to Download Revised Work Plan for East Ravine Groundwater Investigation, PG&E Topock Compressor Station, Needles, California July 24, 2008 51.18 KB
Click to Download Modifications to Hydraulic Data Collection for the Interim Measures Performance Monitoring Program at the PG&E Topock Compressor Station, Needles, California July 14, 2008 115.58 KB
Click to Download Analytical Method Change for Evaluation of Hexavalent Chromium at Pacific Gas and Electric Company (PG&E), Topock Compressor Station, Needles, California (EPA ID NO. CAT080011729) January 19, 2008 37.69 KB
Click to Download Comments on the East Ravine Groundwater Investigation Work Plan Pacific Gas and Electric Company (PG&E), Topock Compressor Station, Needles, California (EPA ID NO. CAT080011729) January 7, 2008 247.91 KB
Click to Download Expanded Metal Analysis at Existing Groundwater Monitoring Wells, PG&E Topock Compressor Station, Needles, California November 6, 2007 1.01 MB
Click to Download Workplan for Groundwater Investigation for Area 10 - East Ravine, PG&E Topock Compressor Station, Needles, California October 29, 2007 39.68 KB
Click to Download DTSC Conditional Approval Letter of Updates and Modifications to GW and Surface Water Monitoring Program September 28, 2007 57.58 KB
Click to Download DTSC Letter Providing Comments on PG&E Responses to Comments on Hydrogeology and Groundwater Sections of February 2005 Draft RFI/RI Report September 19, 2007 227.11 KB
Click to Download DTSC Letter Providing Comments on Corrective Measures/Feasibility Study Work Plan September 3, 2007 1.86 MB
Click to Download DTSC Letter Providing Approval of the PGE-6 Well Decommissioning Report August 10, 2007 48.04 KB
Click to Download Letter to DTSC: Updates and Modifications to Performance Monitoring Program July 27, 2007 83.05 KB
Click to Download Letter to DTSC: Updates and Modifications to Groundwater Monitoring Program July 20, 2007 394.44 KB
Click to Download Email sent July 4 sumarizing PG&E-Agency communications regarding data for RFI-RI Volume 2 for Groundwater July 4, 2007 462.71 KB
Click to Download Well PGE-6 Decommissioning Summary July 3, 2007 2.76 MB
Click to Download DTSC Approval of Work Plan for Anaerobic Core Samples May 1, 2007 39.24 KB
Click to Download DTSC Conditional Approval of Work Plan for Hydraulic Testing in Bedrock Wells April 2, 2007 121.19 KB
Click to Download DTSC Approve Well PGE-6 Revised Decomm Workplan March 28, 2007 97.11 KB
Click to Download DTSC Response to DOI/USGS Comments on Hydraulic Testing in Bedrock Wells WP Addendum March 28, 2007 49.9 KB
Click to Download DTSC Approve Adendum to CA Slant Drilling Workplan January 31, 2007 40.59 KB
Click to Download DTSC Approve Reduced GW Sampling Frequency January 22, 2007 90.79 KB
Click to Download Approval of Addendum 3 to the Floodplain In-situ Hexavalent Chromium Reduction Pilot Study Work Plan January 12, 2007 41.38 KB
Click to Download DTSC Acceptance of Performance Assessment Report for IM3 Injection Well Field January 5, 2007 40.15 KB
Click to Download DTSC Evaluation of Tech Memo: Information Review of GW Conditions in Bedrock Formation November 3, 2006 391.16 KB
Click to Download DTSC Evaluation of Work Plan for Additional GW Characterization Beneath the Colorado River by Slant Boring October 30, 2006 80.58 KB
Click to Download DTSC Approves Request for Modification of Shoreline Surface Water Sampling October 26, 2006 519.49 KB
Click to Download DTSC Review of PGE-6 Decommissioning Work Plan and the Tech Memo: PGE-6 Decommissioning Evaluation October 23, 2006 66.79 KB
Click to Download Slant Boring Plume Investigation Work Plan Letter September 29, 2006 31.84 KB
Click to Download Copy Rescinding of the Request for Approval to Implement Limited Sampling Frequency for Select Metals/General Minerals at IM-3 Injection Monitoring September 6, 2006 187.82 KB
Click to Download Third and Fourth Quarter 2005 Groundwater Monitoring Reports, Compliance Monitoring Program for Interim Measures No. 3 Injection Well Field Area June 9, 2006 229.92 KB
Click to Download Response to Comments on Conditional Approval of Technical Adendum No. 2: Approach to Hydraulic Testing of Wells at Locations 1, 2, and 4 Interim Measures Performance Monitoring May 9, 2006 350.53 KB
Click to Download Conditional Approval of Addendum No. 2 to the Floodplain In-Situ Hexavalent Chromium Reduction Pilot Test Work Plan May 3, 2006 103.59 KB
Click to Download Technical Addendum No. 2: Approach for Hydraulic Testing of Wells at Locations 1, 2, and 4, Interim Measures Performance Monitoring May 3, 2006 451.96 KB
Click to Download Conditional Approval of Chromium Isotope Study Workplan March 22, 2006 766.82 KB
Click to Download Conditional approval of approach to drilling and well installation at locations 1 through 5, well installation workplan for interim measure performance monitoring February 8, 2006 581.83 KB
Click to Download Requirement for revised groundwater flow model report February 3, 2006 153.67 KB
Click to Download Conditional approval to commence start-up of extraction well PE-1 and continued extraction from well TW-3D January 26, 2006 141.42 KB
Click to Download Requirement for chromium isotope study, PG&E Topock Compressor Station Needles, CA January 13, 2006 198.31 KB
Click to Download Conditional approval of the draft well installation work plan for interim measures performance monitoring program, dated 11/30/05 January 6, 2006 524.73 KB
Click to Download Requirement for technical memorandum evaluating potential bedrock fracture porosity and preferential groundwater migration pathways January 6, 2006 21.13 KB
Click to Download IM No. 3 Land Use Area Memo July 8, 2005 939.75 KB
Click to Download Approval with Conditions, Interim Measures No. 3, Dated June 21, 2004, PG&E Topock Compressor Station, Needles, California June 30, 2004 639.38 KB
Click to Download Request for Interim Measures Workplan No.2 (Conversion of Existing Groundwater Monitoring Wells to Extraction Wells): PG&E Topock Compressor Station, Needles, California February 9, 2004 119.88 KB