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COUNTY OF SAN MATEOInter-Departmental Correspondence |
Department of Public Works |
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DATE: |
May 23, 2002 |
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BOARD MEETING DATE: |
June 18, 2002 |
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TO: |
Honorable Board of Supervisors |
FROM: |
Neil R. Cullen, Director of Public Works |
SUBJECT: |
Increase in Contract Authorization - Reconstruction of Manzanita Avenue and Portions of Oakley Avenue and Camino A Los Cerros - West Menlo Park Area (Project No. R3S03, R4Y03-F36[324A]) |
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Recommendation |
Adopt a resolution authorizing an increase of $20,000 in the "Not-To-Exceed" payment limit for contract costs for the Reconstruction Project as described above. |
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Previous Board Action |
Awarded a contract for the Reconstruction of Manzanita Avenue and Portions of Oakley Avenue and Camino A Los Cerros to Interstate Grading & Paving, Inc. |
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Key Facts |
1. |
The original contract had a "not to exceed" limit of $602,000 ($547,240 low bid plus $54,760 in contingencies), which normally would cover all contract costs including differences in final contract quantities as compared to estimated quantities, and any extra work usually associated with reconstructing roads adjacent to existing improvements. |
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2. |
We believe the not-to-exceed limit will be exceeded as a result of our having to do extra work due to pockets of unsuitable material found during subgrade preparation but not identified by our soils investigations; removal of abandoned pipes that we were not aware of; lowering of sewer laterals which conflicted with the construction; replacement of an existing storm drain manhole due to its unsalvageable condition; adjustment of the road profile to improve drainage; additional paving within the Town of Atherton; asphalt concrete backfill for shallow storm drain pipe areas; and additional driveway work necessitated to conform steep driveways. |
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Discussion |
We are anticipating extra work costs for the project to increase the total project costs by an additional $20,000 over the contract "Not to Exceed" amount, primarily as a result of the following: |
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The Contractor encountered: |
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1. |
Unsuitable subgrade material upon excavating the existing roadway at various locations on Oakley Avenue and Camino A Los Cerros - Additional excavation was done in order to stabilize the subgrade and the area was backfilled with asphalt concrete in the subgrade, which serves as additional structural section. This portion of work is estimated at $20,000 and includes the additional excavation, asphalt concrete and additional base. |
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2. |
Abandoned 6" pipe along Oakley Avenue near the edge of the road. Removal of the pipe was necessary to accommodate the grading required by the project. The cost of this work is estimated to be $4,140. |
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3. |
Shallow sanitary sewer lines maintained by West Bay Sanitary Sewer District (West Bay) - Numerous laterals interfered with the roadwork. Conflicting laterals either have been lowered, capped with concrete or replaced if necessitated by the condition of the pipe. The total cost of lowering, placing concrete caps and replacing conflicting sewer laterals is approximately $8,850, which should be reimbursed to the County by West Bay, upon completion of the project. However, West Bay has not agreed to the reimbursement and we are currently working with West Bay to resolve this issue. |
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4. |
Adjustment of road profile - Additional excavation was done in order to lower the road profile of Manzanita Avenue to improve the drainage patterns in the driveway areas to the road. The cost of this work is estimated to be $8,880. |
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5. |
Additional paving within the Town of Atherton - Additional asphalt concrete was used for paving a portion of Camino A Los Cerros in the Town of Atherton limit. The Town will reimburse the County for this work. The cost of this work is estimated to be $3,000. |
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6. |
Asphalt concrete backfill around storm pipes and additional paving - Additional asphalt concrete was used for backfilling the area around shallow storm drain pipes, since this area cannot be cement treated, and for paving areas at various intersections originally not on the plans but necessitated by the poor road condition in this area. The cost of this work is estimated to be $19,000. |
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7. |
Roadway shoulder and driveway work - Additional miscellaneous roadway shoulder and driveway work beyond the original plans was done in order to provide adequate ingress and egress for some of the steeper driveways. We use a minimum standard width for shoulder conforms, but we have found that some of the conform work has to extend farther back as some property owners have vehicles that have minimal clearances and which "bottom out" if the driveways are too steep. The cost of this work is estimated at $8,400. |
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Vision Alignment |
We believe our recommendation is consistent with the Shared Commitment to "Ensure Basic Health and Safety for All" and Goal Number 7, "Maintain and Enhance Public Safety of All Residents and Visitors," as the associated work is an integral part of the work to improve these roads for the benefit of the public. |
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Fiscal Impact |
The proposed changes will authorize an increase in the original "not-to-exceed" amount from $602,000 to $622,000. The actual costs will be based on final quantities of work for the project and on executed contract change orders. |
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Sufficient funds are available in the Road Fund to cover the additional cost. The Town of Atherton will reimburse the Road Fund for the resurfacing of the road within the Town limits and we will continue to work with the West Bay Sanitary District to resolve sewer lateral issues associated with road reconstruction. There is no impact to the General Fund. |
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A form of resolution has been approved by County Counsel. |