Kiewit to rehabilitate CWA's First Aqueduct

Kiewit Infrastructure West Inc. has been given the San Diego County Water Authority contract to rehabilitate a portion of the SDCWA’s First Aqueduct.

A unanimous CWA board vote Dec. 6 approved the contract with Kiewit for $30,400,000. The project will rehabilitate 3 miles of steel pipe lining through 12 access portals and will also rehabilitate 60 pipeline and valve access structures by installing new piping, valves, access hatches and ladders. Although none of the structures are within the Rainbow Municipal Water District or the Fallbrook Public Utility District, Rainbow and FPUD will be impacted by the shutdowns which will allow work on the pipelines.

“This project is a rehabilitation of the First Aqueduct,” Jerry Reed, CWA director of engineering, said. “It is a priority project in our regional asset management program.”

The First Aqueduct pipelines are the oldest in the CWA’s system. Construction on Pipeline 1 began in 1945, and water was first delivered in 1947. Pipeline 2 was constructed between 1952 and 1954 and brought online in 1954. Both are primarily reinforced concrete pipes with welded steel pipe being utilized in high-pressure siphons. The First Aqueduct also includes 10 flow control facilities which were built between 1954 and 1987; some of those flow control facilities connect to both pipelines while others connect to only one. The northern portion of the First Aqueduct runs from the delivery point, where the CWA takes water from the Metropolitan Water District of Southern California 6 miles south of the San Diego County line, to Hubbard Hill in Escondido. Both First Aqueduct pipelines convey treated water.

The southern portion of the First Aqueduct delivers water from Hubbard Hill to the San Vicente Reservoir in Lakeside. Rehabilitation work needed for the southern portion of the First Aqueduct will be addressed by future CWA action.

The CWA has an asset management program which protects the reliability of CWA facilities. Inspection technologies reduce the risk of pipeline failures and are also used to plan pipeline rehabilitation schedules. The asset management program uses an acoustic fiber-optic monitoring system along with internal inspections during aqueduct shutdowns to detect and monitor deterioration of CWA aqueduct facilities.

An inspection of the steel pipelines in the First Aqueduct revealed deterioration of the original pipe lining, which has created corrosion damage. The pipe lining will need to be removed and replaced to prevent additional damage and extend the service life of the pipelines. The structures assessment identified rehabilitation of concrete structures to extend their service life, replacement of valves and piping which are beyond their service life, and abandoning structures which are no longer required to operate and maintain the aqueduct.

CWA staff met with MWD staff, with United States Bureau of Reclamation staff, and with a contractor who has lining rehabilitation experience to determine the most cost-effective method for the lining rehabilitation. The lining will be removed and replaced from the inside to minimize excavation and community impacts.

Some sections of the aqueduct must be taken out of service for the work to be performed, and the work schedule includes allowing construction to occur during extended aqueduct shutdowns. Six of the 10 flow control facilities will need a new interconnection so that they can connect to both pipelines and service can be maintained when one pipeline is shut down. The CWA expects the work to begin in January 2019 and be complete in spring 2021. The first phase will address the six flow control facility turnouts as well as rehabilitate 8,600 feet of lining and 31 valve and access structures while the following year’s phase will rehabilitate 5,900 feet of lining and 29 structures.

The CWA coordinated with its member agencies to ensure that no retail deliveries are interrupted during shutdowns which affect those agencies. The impacted agencies including Rainbow and FPUD will rely on stored water, transfers, and draw from the CWA's Second Aqueduct.

A nonvoting presentation, June 28, to the CWA’s Engineering and Operations Committee estimated the construction cost to be between $12 million and $14 million. When the project was advertised for bid Sept. 28, the estimate had increased to between $19 million and $23 million with $4 million added to address market conditions and $3 million accounting for estimate omissions in mobilization and structure rehabilitation costs. A $3 million allowance was added during the bid period in case groundwater treatment was necessary, which increased the estimate to between $22 million and $26 million.

Three companies submitted bids by the Nov. 1 deadline. Abhe and Svoboda Inc. had the apparent low bid at $27,912,254, but the bid was deemed non-responsive as bid amounts, details of plans for construction and identification of vendors, suppliers and service providers were omitted in the proposal. Kiewit’s $30,400,000 proposal was deemed the lowest responsive bid while J.F. Shea Construction submitted a bid of $31,349,555. The bids include the groundwater allowance; the CWA will not pay that portion if treatment is not needed. The CWA staff analysis to determine the difference between the estimate and the Kiewit bid amount found that Kiewit used a different cement mortar lining method which added $3 million to the cost but which will be necessary due to the project’s pipe size and scope. The analysis also determined that market conditions for pipe and equipment added $1.4 million to the cost.

“The market conditions have changed,” Reed said.

Although CWA staff recommended that the board accept the Kiewit bid, three alternatives were presented for the board to consider.

“Every alternative requires delaying the project,” Brent Fountain, CWA senior engineer, said. “You’re increasing your risk of failure.”

Delaying the project with the hope of better market conditions could produce a favorable change in costs, but the specific reduction is not known and costs could increase.

“We never know what the costs are going to be the next few years,” Lois Fong-Sakai, who is one of the city of San Diego’s representatives on the CWA board, said.

Market trends historically have had two-year to five-year phases, so that would likely be the delay period. In addition to increasing the risk of infrastructure failure delaying the project could impact other projects scheduled for the future since the increased demand for construction contractors could result in higher prices for those projects. An alternative to split the project into three smaller projects might attract additional bidders, but the redesign and re-bidding work along with additional construction management would add $3 million to the CWA’s costs and the one-year delay could also result in higher construction costs.

The third alternative was to have CWA staff perform the construction while subcontracting for specialized tasks such as the steel pipe lining rehabilitation. That would also cause a one-year delay and would require an increase in CWA staff. The project would be outside the CWA’s normal scope of maintenance, and the CWA rather than a contractor would take on the construction risk.

“There wasn’t any benefit to these alternatives,” Fountain said.