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HomeMy WebLinkAboutSCOTCH PINES PUD SEVENTH - Filed GC-GENERAL CORRESPONDENCE - 2004-07-22PARAGON I II]>I [ I I%I (.kI)k-,: December 8, 1999 Mr. Cam McNair, Jr., City Engineer City of Fort Collins Engineering Department P.O. BOX 580 Fort Collins, Colorado 80522 Re: Input Regarding Corrective Actions Village Pump 2601 South Lemay Avenue Fort Collins, Colorado Project Number 1099006 Dear Mr. McNair: w I, i Q1 ,I 2401 Research fnvd_ SuI¢ 206 Ft. Collins, CO R0526 Phone (970) 224-1061 Fax (970)224-1062 DAvlo M. RAu, P.E., DEE SCOTTA. RUTHERFORD, P.E. BRICK SMITH, P.E. JAMES M. TDOMAS, E.I. BRAD C. WOHLER STEVEN A. MARIE, E_1, The purpose of this letter is to request input from the City of Fort Collins (City) regarding corrective actions at the above -referenced site. As you know, a copy of the Corrective Action Plan (CAP), dated December 3, 1999, was submitted to you. The remedial option proposed in the CAP was Option 2 which consists of soil -vapor extraction (SVE) using 17 SVE wells and air sparging (AS) using 29 AS wells on the west side of Lemay Avenue; application of oxygen release compound (ORC0) in probes in and on the east side of Lemay Avenue; and providing an alternative water supply for the Scotch Pines Village Homeowners Association. A conceptuai layout of the proposed option was included as Figure 4 in the CAP and is attached to this letter for your convenience. Please refer to the CAP for spml c information regarding contaminant concentrations observed at the site, sampling locations and the proposed corrective actions. Fight (8) of the 17 SVE wells and 13 of the 29 AS wells are proposed for installation in the public right-of-way as shown on Figure 4. Those wells are proposed for installation where the 7-foot sidewalk is located. We propose that the sidewalk be removed; the wells be nstaPed; process piping be installed and connected to the wells; and the sidewalk be replaced. The ORC") would be installed in two (2) separate phases with the first phase being performed approximately six (6) months after the SVE/AS system becomes operational. 1t is estimated that approximately 4,150 pounds of ORC° would be applied in 176 probes in and on the east side of Lemay Avenue. The probes would be approximately 1-inch in diameter and would be driven to depths of approximately 13 to 16 feet below grade. Pressure injection of the ORCc" I:NA IRONNIFy-TAL ENGINEERING (\11 GE(>HYDROL)GY Mr. Cam McNair, Jr./City of Fort Collins — Village Pump Corrective Actions PARAGON Project Number 1099006 December 8, 1999 Page 2 would be performed, the probe rod would be removed and the hole backfilled according to the City's requirements. Some future factors may impact this portion of the proposed corrective action. For example, assessment northeast of monitoring well MW-10 is still required. if signii-iscant contamination is observed northeast of MW-10, additional probes and ORC° would be required. Conversely, if access to the First Christian Church property is obtained in the near future, this portion of the corrective actions may not be completed and a stand-alone remedial system may be constructed on the east side of Lemay Avenue. More information will be provided to the City as this project progresses. The alternative water supply for the Scotch Pines Village Homeowners Association consists of directionally drilling and installation of piping from Parkwood Lake to the existing irrigation cistern located near the northeast corner of the Scotch Pines Village Shopping Center as shown on Figure 4. The connection of the french drain to the irrigation cistern would also be disconnected as part of that process. Excavation activities would be required in the public right-of-way to accomplish this portion of the CAP. After the CAP is reviewed and approved by the Oil Inspection Section (OIS), the CAP implementation phase will be begin. The CAP implementation phase will consist of design of the remedial system; preparation of construction specifications and drawings; bidding of the project; and construction/installation of the remedial system. A proposed schedule for implementation of corrective actions at the site was included in Appendix F of the CAP and it was estimated that construction of the remedial system would begin in late April of 2000. We will submit the design documents to the City for review wren they are complete which is anticipated to be in March 2000. At this time, we would like any input or comments which the City may have. Specifically, we would like the City's input on the permitting process for this project. We propose that one (1) Right -of -Way Permit be issued by the City for work in the public right-of-way. It is anticipated at this time that the work which will be required in the public right-of-way will consist of the following tasks. Installation of two (2) additional groundwater monitoring wells northeast of MW-10; • installation of eight (S) SVE and 13 AS wells on the west side of Lemay Avenue; Installation of process piping to connect the remedial wells to the rernediation equipment; • Completion of approxinnately 176 probes in and on the east side of Lemay Avenue; Directionally drilling and installation of piping from Parkwood Lake to the existing irrigation cistern; and • Disconnection of the french drain from the irrigation cistern. Mr. Cam McNair, Jr../City of Fort Collins -- Village Pump Corrective Actions Project Number 1099006 PARAGON December 8, 1999 Page 3 Under this proposed 1-permit scenario, we envision overall approval by the City of the conceptual p!an and task -by -task approval of access/traffic control requirements. This scenario would also require approval of at least four (4) contractors working in the public right-of-way at various times. It is anticipated that those contractors would consist of a drilling firm for installation of the monitoring, SVE and AS wells; environmental contractor for excavation activities for the process piping and disconnection of the french drain; direct - push contractor for completion of probes and injection of ORCO; and a directional -drilling firm for installation of piping from Parkwood Lake to the cistern. It is anticipated that Paragon would provide construction observation during the above -mentioned activities and would coordinate with the City on each of the tasks. In addition to the Right -of -Way Permit, we would also submit a Building Permit Application to the City for the treatment building which is proposed for this project on the Scotch Pines Village Shopping Center property. Your timely input regarding corrective actions at this site is greatly appreciated. If you have questions or require additional information regarding this site, please do not hesitate to contact us. Sincerely, PARAGON CONSULTING GROUP, INC. 0 ew d � Scott A. Rutherford, P. Senior Project Engineer sAR/DMR:sar2 enc: Figure 4 — Remediation System Layout Diagram cc: Mr. Stephen.1. Schrader/Schrader Oil Company David M. Rau, P.E., DEE Principal Engineer ( FTC )N:\1999\PROJECTS\1099006\LETTERS\l 099006C!TYO FFTCO LLI N S91208. LTR. 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