Bid Docs and Product Specs

Riverside Rehab Demonstrates Why They Are Critical Project Components

By Paul Gagliardo

In public works construction, bid documents are critical as they define the project scope, requirements, evaluation criteria and products to be used. Creating accurate and complete bid documents and product specifications allows the owner to obtain the project outcome they desire. When attempting to sole-source a product, the specifications take on a more important role. The owner must know exactly what they want and how to prepare a specification that focuses the bidder on this singular product or solution. This also limits the potential bidders as not all contractors have access to all products on the market. When an owner is interested in specifying a new technology or product this task becomes more difficult as there may be no standard specification to use as a model.

Riverside is a city and the county seat of Riverside County, California, in the Inland Empire metropolitan area about 50 miles southeast of Los Angeles. It is named for its location beside the Santa Ana River and was founded in the early 1870s. It is the birthplace of the California citrus industry.

The city owns and operates a sanitary sewer collection system consisting of more than 830 miles of sewer lines ranging in size from 4 in. to more than 50 in. in diameter with some more than 120 years old. There are 19 pump stations located throughout the city that range in size from 100 gallons per minute (gpm) up to 2,000 gpm providing service to those areas of geographic need. Treatment is provided at the Regional Water Quality Control Plant (RWQCP), which provides preliminary, primary, secondary, and tertiary treatment for a flow rated capacity of approximately 46 million gallons per day (mgd). In addition to wastewater from the city’s collection system, the city also provides domestic and industrial wastewater treatment services for the Community Services Districts of Edgemont, Jurupa and Rubidoux. The RWQCP comprises two treatment plants and a common tertiary filtration plant, serving a population of almost 400,000 people. At the plant, wastewater is treated to tertiary levels before it is reused for irrigation or discharged to the Santa Ana River.

In 2024, the City of Riverside faced a significant challenge in rehabilitating a 2-mile-long, 24-in. concrete-lined and coated steel force main pipeline installed in the 1970s. The force main had experienced internal corrosion that affected its structural integrity. Following a failure and major cleanup effort in the early 2000s, the pipeline was decommissioned and left out of service. The city constructed a redundant force main to maintain operations and decided to mothball the original pipeline due to concerns over further failures. The Magnolia Street force main was replaced in 2019. In 2024 dollars a full replacement project is estimated to cost $40 million, or $20 million per mile. The costs include mobilization, traffic control, stormwater control and environmental permits. It also includes street improvements, such as asphalt removal and trenching, curb and gutter replacement, utility relocation and replacement, repaving and striping in addition to the actual force main pipe installation. Increasing demand for system redundancy necessitated the rehabilitation of the abandoned pipeline.

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Municipal pipeline rehabilitation using a liner system generally offers significantly greater value compared to a total replacement. It is typically much less expensive, requires less permitting, causes minimal disruption to the community, and takes less time to complete. It can extend the life of existing infrastructure while still maintaining functionality, making it a more cost-effective option for most situations where the pipeline is not severely damaged.

Rehabilitation methods often cost 50-75% less than full pipe replacement, resulting in substantial savings. When using a Flexible Fabric Reinforced Pipe (FFRP) or a cured-in-place pipe (CIPP) pipelining for pressure applications, the restoration takes place from access pit to access pit. Digging to replace pipes will require more time, be more disruptive, and increase expenses. Because relining projects only have access pits and not open trenches the permitting requirements are much lower. This reduces time to completion, cost, and complexity. Properly rehabilitated pipelines can have their lifespan extended by 50 years, delaying the need for complete replacement. Rehabilitation projects usually take less time to complete compared to full replacement, minimizing service disruptions. Project sections can be opened and closed within a day. The interruptions involved with the trenchless method are minimal. Businesses that require continuous access to utilities benefit from this method. Other factors that occur in the replacement project include negative impacts on business and traffic flow because the trenching requires diverting traffic away from the area where the contractors are digging. Another factor with the dig and replace method is that surface restoration is also necessary.

Since Riverside had already constructed a separate force main pipeline to replace the existing one, they were aware of the cost and disruption implications.  When it came to increasing capacity and redundancy in the area the obvious choice was to rehabilitate the existing pipe with a liner system.

The original Magnolia Avenue Sewer Force Main Rehabilitation project in 2023 focused on the repair and rehabilitation of approximately 9,845 linear feet (lf) of an existing 24-in. cement-mortar lined and coated (CML&C) steel pipe with a CIPP method via downstream inversion and closures at access pits on Magnolia Avenue. The project also included cleaning and closed-circuit television (CCTV) inspection of the pipeline before and after lining as well as all associated work necessary for a fully functional force main.

The city chose a CIPP solution to rehabilitate the pipeline. CIPP is a trenchless method for repairing pipes that involves inserting a flexible liner into an existing pipe, inflating it, and then hardening it with heat or ultraviolet light. CIPP is suitable for repairing pipes that do not need to be upsized and can be completed in less time than other methods. CIPP is the technology of choice for rehabilitating gravity sewer mains but can also be used on force mains.

This technology is currently the most common method used in pipelining projects. The specifications used by the city in the bid process required contractors to bid using the CIPP solution. The bid proposals received exceeded the $7 million budget by more than 30%. Because the bids received were so high, the bids were rejected and an alternative solution was sought.

CPM Pipelines introduced the city to the BulletLiner System solution. The BulletLiner System®, a close fit Flexible Fabric Reinforced Pipe (FFRP) solution, is a long-lasting, corrosion-resistant alternative to CIPP, designed for both low pressure and high-pressure applications intended to extend the lifespan of pipelines without the need for full replacement.

This close fit solution is a three-layer system comprised of an inner woven layer of polyester or Kevlar with an outer jacket and inner liner layer embedded through the woven fabric layer, creating a seamless, high-strength, semi-structural liner inside the pipe. This combined with the structural capacity of the host pipe creates a structural class III system. This process restores pipelines while preserving their flexibility and preventing leaks, making it ideal for force main applications.

While CIPP and Loose Fit liners are commonly used in pipeline rehabilitation, they have notable drawbacks:

• CIPP (Cured-in-Place Pipe): Requires extensive curing time and can become brittle over time, leading to cracks and failures.
• Loose Fit Liner: While durable, it is a flexible liner that does not allow for a class III installation and is unable to bridge gaps and holes in the host pipe.  There is a dramatic reduction in host pipe ID as the system is loose fit and meant to operate completely independent of the host pipe.  The system is unable to take advantage of the remaining structural and operational capacity of the host pipe it operates within. 

The BulletLiner System is just one example – a cost-efficient approach introduced to the U.S. market by CPM Pipelines in 2013. It is a semi-structural Class III pipe FFRP rehabilitation system. It is NSF 61 approved and suitable for the transportation of various liquids including potable water, reclaimed water, wastewater, hot water, gas, oil, chemical, with drinking water approvals in numerous countries. These types of liner systems have been internationally proven for more than 25 years and the BulletLiner manufacturer has been producing these lining systems for 12 years. This method has been used to rehabilitate more than 200 pipeline segments totaling more than 1,000 km of pipe length. The system has a basic three-step installation procedure;

1) Fold the liner into a U-shape;

2) Full the liner through the host pipe;

3) Expand the liner.

There is no connection between the pipe and liner, so the liner works independently from the pipe. The slightly rigid liner maintains a round shape inside the pipe even without pressure. It is flexible and can easily be pulled through 45-degree bends. The liner is flexible, foldable, and light with the material strength of a steel pipeline. Due to the extreme flexibility, it opens up a variety of rehabilitation applications without having to trench and remove pipelines. Installation requires two small excavation pits or access points for rehabilitating a deteriorated section of pipe. This reduces the conventional pipeline replacement noise, traffic disturbances, time-consuming reconstruction as well as environmental and economic impacts to surrounding landscape and businesses. This system, designed for restoring the structural integrity of aging pipelines, offers several advantages, including requiring less access pits, streamlining installation and providing a similar solution to CIPP at a lower cost.

Trenchless rehabilitation techniques require minimal excavation, reducing surface disruption and inconvenience to residents and businesses. FFRP systems can be pulled 2,000 ft or more between access pits depending on size and geometry. In some cases, when pipe is straight, it can be pulled up to 8,000 ft. Minimizing access pits reduces costs and impact on the surrounding community and traffic.

The city revised its specifications and bidding documents to allow for the use of this technology. The project was re-bid and SAK Construction emerged as the sole bidder, meeting the city’s budgetary and technical requirements. By reducing access pits from 20 to 11 and liner installations from 15 to 8, the close fit FFRP solution brought the project back within budget at $6.75 million. Completed in late 2024 the project achieved a renewed pipeline with a 50-year design life with a five-year warranty. 

The revision of the specifications was the critical component in ensuring that the city could rehabilitate the pipeline to their specifications and within budget.

The city originally prepared the bid documents specifying a CIPP liner system.  This is the standard option that is customarily used by utilities to line pipelines. The FFRP solution is relatively new, and many owners are not aware of the product and that it is equivalent to CIPP in many ways. In addition, there is not a widely available specification that has been used in multiple applications that can be easily incorporated into a set of bid documents.  When more of these projects are successfully implemented a more complete and overarching set of specifications can be created to allow for both types of solutions to be bid on the same project under the same set of rules. 

A utility may be unsure of trying a new technology especially when a tried and true set of specification has not yet been developed. The two alternative solutions are not mutually exclusive but do have some specific differences that must be accounted for in a bid specification.  It is incumbent on the owner or engineer to create a set of bid documents that are complete and accurate and allow for alternative solutions to be proposed. This makes the specifications more complex and more time-consuming to prepare.  When bid document preparers have more experience this will become more commonplace.

The City of Riverside has successfully modernized its sewer infrastructure and maintained redundancy while adopting an innovative, cost-effective solution. This project underscores Riverside’s commitment to proactive asset management and positions the city as a leader in adopting new technologies to enhance utility performance.

Paul Gagliardo, MPH, P.E., is an independent consultant providing advice to firms interested in the municipal water business. Gagliardo created and operated a water technology research center in the City of San Diego and directed the Innovation Program at American Water for nine years. He is the host of The Water Entrepreneur podcast.