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RMWD approves lift station construction management contract change order

Joe Naiman

Village News Reporter

The Rainbow Municipal Water District board approved a change order to the construction management contract for the replacement of Lift Station No. 1.

The board’s 5-0 vote authorizes a change order with Valley Construction Management which adds $216,413 to the contract amount. The change order also extends the contract term through March 29, 2024.

Lift Station No. 1 is off of Old River Road and delivers sewage effluent to the City of Oceanside, which has an ocean outfall. The package lift station has three five-horsepower wet well/dry well pumps and a 750 gallon working volume wet well. The pump station was built in 1974, and the pumps were replaced in 1994.

The lift station's firm capacity is 1,250 gallons per minute (gpm). During wet weather flows the station pumps an average of 1,400 gpm by running pumps up to 13 times per hour. Additional development is expected to increase the necessary lift station volume, and the ultimate required capacity is more than 2,600 gpm.

The lift station is also in need of structural, electrical, and mechanical repair. Rainbow's 2000 master plan identified the need for the eventual replacement of Lift Station No. 1 and adjacent pipelines.

“We had an overburdened system,” said current Rainbow board president Hayden Hamilton.

In March 2014, Rainbow's board approved a contract with Kennedy/Jenks Consultants (former Rainbow general manager Tom Kennedy is not related to the principal with the Kennedy/Jenks consulting firm) to provide design, environmental permitting, and construction oversight services for the replacement of Lift Station No. 1.

Kennedy/Jenks submitted a pre-design report which summarized the required improvements. The report stated that upsizing the existing sewer siphon to accommodate the predicted ultimate flows would require a new siphon to be drilled horizontally under the San Luis Rey River with a depth of approximately 80 feet in order to avoid bedrock.

A new lift station on the north side of the river would avoid the need for a deep siphon, and after a 1.36-acre site on Thoroughbred Lane adjacent to Bonsall Village Center became available, Rainbow's board approved the purchase of that property in February 2017.

The initial design was re-evaluated and it was determined that upsizing a stretch of sewer main along State Route 76 and placing an equalization basin upstream of the existing siphon could level out the flows through the siphon to meet existing capacity requirements for Lift Station No. 1.

Moving the flow equalization upstream would also allow the new Schoolhouse Lift Station at Old River Road and Calle De Las Estrellas to replace Lift Station No. 1 without upsizing the line to the Old River Lift Station. The equalization basin will be near Thoroughbred Road and Highway 76.

Dexter Wilson analyzed Rainbow's existing wastewater conveyance system to determine what facilities would be needed to accommodate the sewer discharge requirements for what was originally called the Meadowood development and is now called Citro.

The needs included the Thoroughbred Lift Station and appurtenant pipeline modifications, a force main from the Thoroughbred Lift Station to Old River Road, upsizing the existing sewer line along Highway 76, and a gravity main from Olive Hill Road to the Thoroughbred Lift Station. The analysis also projected needed improvements to wastewater facilities along North River Road and to gravity sewer mains along Old River Road.

Some of the improvements recommended by Dexter Wilson were included in draft scenarios prepared by Kennedy/Jenks but never completed. In December 2020, the Rainbow board approved a change order to the Kennedy/Jenks contract for the design of the Thoroughbred Lift Station, the force main, the upsized sewer line along Highway 76, and the gravity main along with the necessary documentation for California Department of Transportation permitting and an environmental Mitigated Negative Declaration.

A January 2021 Rainbow board action approved the environmental analysis prepared by Kennedy/Jenks and formally approved the project which was already in the district's five-year capital plan, although the approval of the project did not include the approval of any designs or other plans nor did it authorize a construction contract or appropriate any funding.

The environmental documentation also covers the force main from the Thoroughbred Lift Station to Old River Road, upsizing the existing sewer line along Highway 76, and the gravity main from Olive Hill Road to the Thoroughbred Lift Station.

Two separate October 2021 Rainbow board actions approved a $15,181,157 construction contract with James W. Fowler Company and a $1,423,717 professional services agreement with Valley Construction Management for construction management and inspection services.

The original contract with Valley Construction, which is headquartered in San Diego, was for 28 months and covered one month for the pre-bid services, 24 months for the expected construction duration, and three months of post-construction services for the closeout period.

The inability to obtain the necessary materials has delayed the project. The schedule increased from 369 to 538 working days, and the project now has an anticipated completion date of March 4, 2024.

“The delay is dictated by supply chain problems,” Hamilton said.

The County of San Diego imposed unexpected work limitations, so J.W. Fowler added two working shifts for the force main installation near Old River Road. The additional shift was not anticipated and was not budgeted in the original project scope of services. J.W. Fowler also indicated that subsurface conditions have changed, so Rainbow requested supplemental geotechnical work which was also unanticipated and not budgeted.

The change order brings the total Valley Construction Management contract amount to $809,184.80. The $216,413 change order covers $30,895 for construction management, $132,518 for construction inspection, and $53,413 for geotechnical and material testing.

 

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