SUBJECT: APPROVAL OF MONTEREY-RIVERSIDE SUPPLEMENT SANITARY SEWER PROJECT CONTRACT CHANGE ORDER NO. 2 (CCO #2) AND ADOPTION OF APPROPRIATION ORDINANCE AMENDMENTS FOR THE SANITARY SEWER CONNECTION FEE FUND
COUNCIL DISTRICT: 2
SNI AREA: N/A
It is recommended that the City Council approve the following:
a. Approval of Contract Change Order No. 2 with Elmore Pipe Jacking, Inc., for the Monterey-Riverside Supplement Sanitary Sewer Project in the amount of $541,009.80, for a total contract amount of $4,770,736.97, and extending the contract by 54 working days to January 31, 2002. CEQA: Exempt.
b. Adopt the following Appropriation Ordinance amendments in the Sanitary Sewer Connection Fee Fund:
1. Increase the Monterey-Riverside Supplement project by $541,000
2. Decrease the Ending Fund Balance by $541,000
BACKGROUND
The Monterey-Riverside sanitary sewer system provides service to southern parts of San José from Santa Teresa Boulevard and Bailey Avenue north to Hillsdale Avenue and Monterey Highway. The proposed project will construct a 42-inch diameter sewer tunnel through Tulare Hill, abandon the existing pumping station, remove and reconstruct manholes and sewer lines near the intersection of Bailey Avenue and Santa Teresa Boulevard, and construct various other appurtenant work. The sewer through Tulare Hill was planned to be installed by microtunneling because of the substantial depth of cover (up to 50 feet) over the pipeline.
Due to the variable subsurface conditions in the Tulare Hill area, the City’s consultant performed an expanded geotechnical investigation during the design phase. The contractor also performed an additional geotechnical investigation during the initial phase of microtunneling as required by the contract documents. Based on the findings of the investigations, the microtunneling process was further refined.
However, during construction excessive wear and breakdowns of the microtunneling machine prompted four separate, unanticipated geotechnical investigations by both the contractor and the City’s consultant. It was discovered that the subsurface conditions were exceptionally variable in the project area. Substantial differences in subsurface conditions were encountered within 30 feet of one of the initial investigation points.
Subsequently, Change Order No. 1 was executed to substitute from microtunneling to conventional tunneling. While conventional tunneling is more costly, it is more appropriate because it allows more excavation options under these unpredictable subsurface conditions. The cutting face of the conventional tunneling machine may be accessed in-place, an option that is not possible with microtunneling. The ability to inspect and maintain the cutting face while in-place is highly desirable while tunneling through such unexpected conditions. In order to inspect and maintain the microtunneling machine, a vertical access shaft must be constructed and the machine retrieved from above ground. Based on an estimated rate of production at a negotiated lump sum rate of $1,001.87 per hour, the resulting net cost of Change Order No. 1 was $98,452.17.
The conventional tunneling operation did not yield the expected production rate due to extremely variable conditions being encountered. Several strata of material ranging from clay to sand to rock were encountered within the first 50 feet of conventional tunneling. Change Order No. 2 addresses additional costs related to the lower than expected production rate. Based on the findings of an additional geotechnical investigation, a revised production rate was estimated. At this revised production rate, it was determined an additional 540 hours of compensation for labor, equipment and materials will be required for the completion of the tunneling operation. A 54 working day time extension will also be authorized by this change order.
City staff has previously negotiated and deemed reasonable the lump sum rate of $1,001.87 per hour for the work required for the conventional tunneling operation.
Council approval of this change order and appropriation of additional funds to pay for the change order will preserve the ability to approve additional change orders up to the previously approved contingency amount.
Not applicable.
COORDINATION
This project has been coordinated with the Departments of Planning, Building and Code Enforcement, and Transportation, and the Offices of the City Attorney, Budget, Risk Manager and Equality Assurance.
1. COST OF RECOMMENDATION: $541,009.80
2. COST OF PROJECT:
Project Development $ 10,000.00
Consultant Agreement 565,500.00
Design & Construction Management 400,000.00
Construction 4,131,275.00
Contingency 314,547.83
Previous Contract Change Order No. 1 98,452.17
Contract Change Order No. 2 541,009.80
TOTAL $6,060,784.80
3. SOURCE OF FUNDING: 540 – Sanitary Sewer Connection Fee Fund
4. START DATE OF CONSTRUCTION: August, 2000
5. ESTIMATED COMPLETION DATE OF CONSTRUCTION: January, 2002
Fund: 540
Appn: 6628
R.C.: 066513
Amount: $503,000
Budget Document: 2001-2002 Appropriation Ordinance, amended on October 16, 2001, Ordinance 26492
NONDISCRIMINATION
The City of San José Nondiscrimination Requirements are included in this project as required by Chapter 4.08 of the San José Municipal Code.
CEQA
Exempt.
RAJEEV BATRA LARRY D. LISENBEE
Acting Director, Public Works Department Director, Budget Office