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HomeMy WebLinkAboutAGENDA REPORT 1995 0419 CC REG ITEM 11MITEM 11• N P City of Moorparl� To: The Honorable City Council From: Ken Gilbert, Director of Public Works Date: April 10, 1995 (Meeting 4- 19 -95) Subject: Consider Change to the Scope of Work for the Tierra Rejada Road Slurry Seal Project OVERVIEW This report discusses the merits of 1) revising the subject contract by deleting the proposed application of Type II Slurry Seal on Tierra Rejada Road; 2 ) installing a subsurface drainage system in the project area; and, 3) constructing an Asphalt Overlay on this street segment in -lieu of Slurry Seal. BACKGROUND 1. On October 5, 1994, the City Council awarded a contract for the construction of road repairs and the application of a Type II Slurry Seal to that portion of Tierra Rejada Road from a point west of Spring Road westerly to the Arroyo Simi Bridge. 2. On February 1, 1995, the City Council approved an increase in the appropriations and the budget for the project in the amount of $25,000 to fund a contract change order to increase the amount of asphalt removal and replacement. DISCUSSION A. Subsurface Water Problem With the recent rains it has become apparent the intrusion of subsurface water into the base material for Tierra Rejada Road is, has been and (if left unchecked) will continue to pose a threat to the longevity of the street. It is suspected that this may be one of the major causes for the early deterioration of Tierra Rejada Road and the recent dramatic increase in the quantity of asphalt removal and replacement required for the subject project. The present Slurry Seal project has been placed on hold until this matter can be adequately discussed and a plan of action determined. trsly=2 Tierra Rejada Slurry Seal April 1995 Page 2 Subsurface water can be intercepted and conveyed to storm drain inlets by means of a subsurface drainage system. Such a drainage system consists of perforated plastic pipe, wrapped in geofabric and placed in a rock filled trench. The drain line may be place at the lip of gutter or (where possible) behind the sidewalk at the edge landscaped slope. It is estimated that it will be necessary to install approximately 15,000 linear feet of this drain line in order to adequately address the problem. The estimated cost for this improvement is $230,000, including design, inspection and contract administration. B. Change Order Deferring Slurry Seal If the City Council determines that it would be prudent to construct the above described drainage system, it is recommended that consideration be given to amending the pending Slurry Seal contract to delete the application of the Type II Slurry Seal. Work under that contract would be limited to the asphalt repair work and crack sealing work performed to date. A summary, of contract costs to date is as follows: Initial Contract Amount 106,563 Current Contract Amount 133,768 Cost of Work Completed 85.752 Cost Reduction 6.1,533 Less Mobilization Etc. -----5,000 Net Cost Reduction 48,146 A figure of $5,000 has been identified as the estimated additional cost to the contractor for the mobilization of his manpower and equipment just prior to the cessation of work. Staff is in the process of negotiating the final cost. C. Asphalt Overlay As you are aware, the quantity of asphalt removal and replacement (R &R) patch areas increased dramatically from the quantity estimated during the design of the project. Normally, it would be preferable to keep the amount of R &R tralyCO2 0010 Tierra Rejada Slurry Seal April 1995 Page 3 areas to a minimum when applying a Slurry Seal to an arterial street. Too many patches under slurry seal applied to a street which accommodates higher speeds leads to "ridability" problems - --- or a ride which is not as smooth as should be expected. In that staff is asking the City Council to consider approval of the construction of the above described drainage system and, as a minimum, the postponement of the application of a Type II slurry seal, consideration should be given to changing the design for the resurfacing of this street by deleting the slurry seal and constructing an Asphalt Overlay. It is estimated that the construction of an asphalt overlay on that portion of Tierra Rejada Road, from a point west of Spring Road to the Arroyo Simi bridge, will cost approximately $600,000, including design, inspection and contract administration. The cost of this method of resurfacing is far greater than the application of a Slurry Seal. However, in the opinion of staff, the benefits of this approach in terms of the longevity of the street, ridabili.ty, appearance, etc. justify this additional expense. If approved, this street could be added to the Asphalt Overlay project, which is funded by a federal Surface Transportation Program (STP) grant, which is now in design. It is recommended, therefore, that the City Council approve this change in the design for the resurfacing of this street segment. D. Fiscal Impact 1. Current Project: A re -cap of the present total project cost estimate is as follows: Amount ($) Construction: 127,848 Contingency: 17,152 Admin & Insp: 15,000 c160,000 trslyCO2 00168 Tierra Rejada Slurry Seal April 1995 Page 5 RECOMMENDATION Staff recommends that the City Council take the following actions: 1) authorized staff to proceed with the preparation of a design and the solicitation of bids for the construction of a subsurface drainage system along selected portions of Tierra Rejada Road; 2) authorize staff execute a Change Order to the contract for the subject project to delete the application of slurry seal and to authorize payment not to exceed $5,000 to cover mobilization and related posts; and, 3) approve the addition of the subject segment of Tierra Rejada Road to the 1995 A/C Overlay Project. trslyCO2 00170