Title
Environmental Management Director recommending her signature be ratified on Change Order No.2 to Contract 031-PW-06/07-BOS with D&E Construction, Inc. to supply and install additional LLDPE geosynthetic liner and geocomposite drainage layer material for the construction of the Final Cover, Union Mine Landfill 13.6 Acre Final Closure project.
RECOMMENDED ACTION: Approve.
Body
BUDGET SUMMARY: |
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Total Estimated Cost |
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$28,875.12 |
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Funding |
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Budgeted |
$ |
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New Funding |
$ |
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Savings |
$ |
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Other |
$ |
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Total Funding Available |
$28,875.12 |
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Change To Net County Cost |
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$0.00 |
Fiscal Impact/Change to Net County Cost: Funding for the Change Order is available in the FY 2007-08 CSA #10 proposed budget. There is no cost to the General Fund.
Background: The closure for the 15.8-acre Class III Old Landfill at the Union Mine Disposal Site specified by the Central Valley Regional Water Quality Control Board (CVRWQCB) in new Waste Discharge Requirements Order No. R5-2006-0020 was required to be completed by August 15, 2007. As part of the Final Closure Plan, submitted to the CVRWQCB on March 30, 2006, it was identified that 13.6 acres of the 15.8-acre Class III Old Landfill Area would receive final cover in the year 2007. The remaining 2.2 acres are scheduled to be closed in the year 2040, the projected closure date of the Class II active disposal area.
The closure of the Union Mine Landfill project was divided into three components for bidding purposes. The first component being the supplying and hauling of soil for the Vegetative Cover, the second being the supplying and installation of the Geosynthetics, and thirdly, the construction of the Final Cover.
On May 22, 2007, the Board awarded a contract to D&E Construction, Inc. of Visalia, California to purchase and install the Geosynthetics for the construction of the Final Cover, 13.6-acre old Union Mine landfill area in the amount of $624,637.50.
Reason for Recommendation: The line items in the Bid Schedule for LLDPE Liner and Double-Sided Geocomposite Drainage Layer were 592,500 square feet. In order to save costs relative to time and material that is associated with engineering fees, this project was approached from a "design build" perspective. Through this process at least three months of engineering design work and approximately $150,000 in consulting service fees was saved.
During the period of construction, the Board approved one change order on August 14, 2007, for $49,500 to supply and install additional geotextile material due to unforeseen subgrade conditions and to prevent long term damage to the LLDPE liner.
Change Order No. 2 was issued for $28,875.12 to supply and install an additional 30,275 square feet of LLDPE geosynthetic liner at $.50 per square foot, and 26,675 square feet of geocomposite drainage layer material at $.515 per square foot. Based on the construction quality assurance survey conducted by Carlton Engineering, Inc., panel layout drawings, and the actual lined area computed from the design drawings, the revised area is 622,775 square feet and 615,775 square feet, respectively. This increase is primarily due to slope corrections and the additional liner required to ensure that the liner is terminated at the anchor trench located at the lower bench. In addition, the Construction Drawings require a 2-foot overlap on the northern and eastern boundaries. This increases the "lined" area another 3,400 square feet for the LLDPE and Geocomposite material. Lastly, the lower anchor trench requires that 2 feet of LLDPE be placed in the anchor trench and backfilled with soil for a future tie-in. The additional LLDPE required for this detail was 3,600 square feet. Therefore, D & E Construction should be compensated for furnishing and installing 622,775 square feet of LLDPE Liner and 619,175 square feet of Double-Sided Geocomposite Drainage Material.
In order to meet the project deadline of August 15, 2007, as required by the California Regional Water Quality Control Board, and to avoid potential demobilization and/or stand-by charges from related contractors, a change order was issued and signed by the Director of Environmental Management. A delay in the project would have resulted in fines and contractor stand-by charges of up to $36,260.00 per week. The Department is requesting the Board ratify the Director's signature on the attached Change Order request.
Change Order No. 2 represents a 1.6% increase to the overall closure cost of $1.8 million.
Action to be taken following Board approval: The Department will execute the attached Change Order.
Contact: Gerri Silva, Environmental Management Director
Concurrences: