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05-0619_RBF CONSULTING_Staff Memo1 .k i TO: Dave Adams, City Manager FROM: Amy Amirani, Public Works Director SUBJECT: Avenida Placida Landslide SITUATION 0 July 20, 2005 As you are aware, an ancient landslide within the slope above Avenida Placida was recently reactivated. Staff has worked closely with the City's Geotechnical Consultant, Lawson and Associates Geotechnical Consulting (LGC) to formulate mitigation measures to minimize impacts to the residential community located below the slide area as well as the existing domestic water facilities located above the slide area. The domestic water facilities that are impacted include the 1 million gallon Krum Reservoir and the 701 S pipeline system. These facilities are an essential portion of the City's domestic water system and serve communities in the southeastern portion of the City. The recommended mitigation measures are as follows: 1. Install three slope inclinometers at the existing domestic water reservoir site to allow continued monitoring of any slope movement. 2. Perform three exploratory borings within slide area to verify the characteristics of the landslide. 3. Perform remedial grading work to remove landslide debris which has impacted an existing de -silting basin along Via Placida. 4. Protect the existing 701 S pipeline running above the slide area. Staff has directed LGC to proceed with the installation of the three slope inclinometers as well as the three exploratory borings on an emergency basis. LGC expects to complete the installation of the inclinometers and exploratory borings by July 22nd Staff has solicited proposals from five local engineering firms to prepare plans for the remedial grading work, and engineering studies for the protection of the water line. Of the five firms, two submitted cost and scope proposals for consideration: RBF Consulting (RBF) and Tetra Tech, Inc. (Tetra Tech). RBF submitted a cost proposal of $95,496 and Tetra Tech submitted a cost proposal of $97,900. Given RBF's experience with ongoing slope stabilization efforts associated with the City's Terminal Reservoir No. 3 project, staff recommends that a Personal Services Agreement be awarded to RBF for a total of $95,496. Staff recommends that the Agreement be awarded on an emergency basis so that the grading plans and engineering studies may be completed in a timely manner. The Agreement has been ti Memorandum • July 20, 2005 Paqe 2 approved as to form by the City Attorney and has been executed by the contractor. The Agreement is attached for your review and final execution. It must be noted that once the engineering studies for the water line protection are completed and the most cost effective option for protecting the water line has been selected, a subsequent agreement for final engineering plans will need to be executed. FINANCIAL CONSIDERATIONS The preliminary construction estimates from the consulting engineers is estimated at $3.5 Million. Upon completion of the grading plans as well as final engineering plans for the waterline protection, a more accurate estimate can be prepared. Staff will provide an updated estimate once it is available. This work was unanticipated and is not included in the FY 05/06 Budget. Staff will seek FEMA reimbursement for the aforementioned costs. If you have any questions or require more information, please do not hesitate contact me at extension 6361. Attachments: 1. Personal Services Agreement — RBF Consulting, Inc.