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HomeMy WebLinkAboutAgenda Report - June 18, 2014 C-09AGENDA ITEM Cq Crrv or Lou Couucrr CovrMUNrcATroN rM AGENDA TITLE: MEET¡NG DATE: PREPARED BY: Accept lmprovements Under Contract for Western and Southern Plumes Monitoring Wells lnstallation Project June 18,2014 Public Works Director RECOMMENDED ACTION Accept improvements under contract for Western and Southern Plumes Monitoring Wells lnstallation Project. BACKGROUND INFORMATION:The contract was awarded to Applied Water Resources, of Walnut Creek, in the amount of $344,502.50. The contract has been completed in substantial conformance with the plans and specifications approved by City Council. The Groundwater Monitoring Plan for the Western and Southern Plume Areas, prepared in February 201 1 by Treadwell and Rollo, established a groundwater monitoring and reporting plan for the Western and Southern Plume areas. Previously conducted investigations have generally defined the extent of the groundwater pollution as shown in Attachment A. The pollution is industrial solvents PCE and TCE, which are found in the soil and groundwater in parts of central Lodi. Using the City's groundwater model prepared by Treadwell and Rollo, combined with the results of previous investigations and in cooperation with the Regional Water Quality Control Board (Board), locations and depths were identified for additional monitoring facilities. As a result, three monitoring wells were constructed at the locations identified in Attachment B fl/VMW 1A,B,C,D; WMW 2 A,B,C; and SMW 1A,B). At each monitoring well location, two to four discrete depth levels were monitored using nested monitoring wells, each constructed to sample from a single discrete depth. The final discrete depths and associated well screen locations were determined during construction and in consultation with the Board. On November9, 2012, the Board issued approval of the draft plan for these monitoring wells. Following installation of the new monitoring wells, a quarterly monitoring program will be implemented that will include one existing monitoring well in the Western Plume and 13 existing monitoring wells in the Southern Plume. Preparation of the existing monitoring wells and execution of the monitoring program is a part of the Monitoring Program contract previously awarded to Stantec Consulting Corporation. The monitoring program will allow the City to track PCE and TCE in the groundwater, which will guide future remediation efforts, if necessary. The contract completion date was April 4, 2014. The final contract amount is $288,719.36. There were two change orders. Change Order No. 1 was to relocate wellWMWI due to a conflict with an existing water main ($12,713.83). Change Order No. 2 was due to requested changes by the property owner at K:\WP\P ROJ ECTS\WATER\PC E, APPROVED , City Manager 6t2t2014 Accept lmprovements Under Contract for Western and Southern Plumes Monitoring Wells lnstallation Project June 18,2014 Page 2 the well SMW 1AB site ($5,639.40). The difference between the original contract amount and the final contract amount was due to a decrease in unit quantity items. Following acceptance by the City Council, as required by law, the City Engineer will file a Notice of Completion with the County Recorder's office. The notice serves to notify vendors and subcontractors that the project is complete and begins their 30-day period to file a stop notice requiring the City to withhold payments from the prime contractor in the event of a payment dispute. FISCAL IMPAGT:Not applicable FUNDING AVAILABLE:This project was funded by Western Plume (194) and Southern Plume (191) funds. Jìr F. Wally Sandelin Public Works Director Prepared by Gary Wiman, Construction Project Manager FWS/GWpmf Attachments cc: City Engineer/Deputy Public Works Director K:\WP\PROJECTS\WATER\PCE,TCE\WestSouthMonitorWellslnstall\CAccept.doc 6t2t2014 Attachment A @A @A @A Vine St.Lee Av.Hutchins St.School St.Church St.Pleasant Av.Stockton St.Park St.Sacramento St.Kettleman Ln. / Hwy. 12 Ribier Av. Rimby Av. Alicante Dr. Cardinal St. Windsor Dr. Tamarack Dr. York St. Brandywine D r .Rose St.Sierra Vista Pl. Maxwell St.California St.Sutter Ln.Akerman Dr.Saratoga Wy.Lowe St. Pinot Noir D r .Mendocino Dr. Village St.Stockton St.Park St.School St.Sacramento St.Church St.Tamarack Dr. Sierra Vista Pl. WMW 2 WMW 1 SMW 1 American Legion Park µWestern and Southern PlumesMonitoring Wells Installation ProjectVicinity Map 1 inch = 500 feetPath: K:\DESIGN\Projects\Monitoring Well\Mon_Well_Loc2.mxd