Municipal pipe market spend makes up 30 percent of overall utility CAPEX for water infrastructure. In part, to address aging pipes, bursts, and other leakage management issues, the pipe market is turning to new materials (plastic) and new technologies (trenchless).
More than $234 billion (USD) of capital expenditures (CAPEX) are forecasted over the next decade to address aging municipal water and wastewater pipe network infrastructure, according to Bluefield’s forecasts. Precipitated by decades of underinvestment, municipal utilities are under increasing pressure to address deteriorating linear assets at a faster pace.
Water losses through leaks for U.S. utilities average 15 percent annually, with some cities, towns and communities losing more than half of all water pumped and treated for distribution to customers. As a result, rehabilitation of existing pipes is the fastest growing spend category, increasing annually from $253 million in 2019 to $576 million by 2028. Network expansions, particularly in high population growth across the sunbelt states (e.g. Texas and Arizona), will drive the lion’s share of spend on new build.
As the estimated national average age of water pipes climbs — from 25 years in 1970 to 45 years in 2020 — largely because of underinvestment, utilities are increasingly forced to replace and rehabilitate linear assets at a faster pace. While asset age is not the sole determinant of asset quality, it is a quantitative signal towards market conditions.
New Materials Reshape Footprint
Piping infrastructure in the United States has been installed in three waves — 1800s, 1900 to 1945, and post 1945. Each wave has brought about a transition in the preferred material type. The material used in the installed pipe assets also varies by geography, as it relates to pipe age. The Northeast and Midwest have the oldest networks and therefore the greatest reliance on legacy cast iron pipes.
The pipe market is undergoing a shift in material types from traditional, legacy materials, like ductile iron and steel, to newer materials including pre-stressed concrete and various plastics — PVC, HDPE and PE. Regional differences in the installed materials, as well as varied procurement processes for various utilities will drive material selection.
New, greenfield pipe networks are most likely to source plastic pipes, which have lower upfront costs and are easier to install. However, they have a shorter lifespan than legacy materials and may result in greater lifecycle costs.
Much of the new pipe networks laid in the United States are installed by private developers to connect new commercial and residential units on the fringes of existing service areas. These private developers are more motivated by upfront costs and ease of installation as compared to established utilities that are more likely to consider the full lifecycle costs of pipe materials.
Current annual replacement rates of less than 1 percent are only slowly changing the material mix of pipes in the group. While traditional pipe materials — iron, steel and cement — will continue to dominate older water and sewer networks. Plastic pipes — PVC, HDPE and PVCO — make up 35 percent ($17.3 billion over 10 years) of total pipe spend, while legacy materials — ductile iron, steel, concrete and other materials — make up the remaining 65 percent, or $32.5 billion.
Emerging material types are also growing faster than the sector as a whole, with average annual growth of 4.5 percent in plastic pipe investment, compared to 2.1 percent average annual growth for legacy materials.
Conversely, long-established utilities with existing network infrastructure continue to replace aging pipes with traditional materials — ductile iron, steel and concrete. Emerging pipe material suppliers face an uphill battle trying to convince conservative utilities to move away from legacy materials, despite potential cost savings. Traditional pipe materials — iron, steel and cement — dominate older water and sewer networks, especially in large cities with old utilities in the Northeast and Midwest, which have the oldest networks in the country and a much higher reliance on already installed iron pipe networks.
Further, the disruption caused by pipe breaks and replacement in densely populated cities is much higher than in rural areas, making urban utilities more sensitive to pipe breakage rates and lifespans when evaluating various material types. Ductile iron scores very well on both of these measures, further enforcing its continued use.
Impact of Trenchless on Pipe Material Types
With installation costs including labor and paving making up 68 percent of total network CAPEX, buyers are looking to trenchless solutions for pipe replacement and rehabilitation in order to reduce network maintenance costs. The trenchless rehabilitation market has steadily grown over the past 40 years but has only begun to take hold with increased suppliers and solutions in the last decade.
Trenchless solutions can typically be applied quicker, with less initial planning efforts and lower interference with the environment. Trenchless technology solutions experiencing increasing popularity, with horizontal directional drilling (HDD), microtunneling and cured-in-place pipe (CIPP) being among most frequently used methods. The applicability of each technology depends on various factors, such as pipe diameter, material type, and soil consistency.
Trenchless technology solutions usually come with a higher up-front cost (up to 30 percent compared to open-cut), due to the necessary sophisticated machinery and engineering know-how. Some rehabilitation techniques, such as in-place repairs, also come with a shorter design life, compared to full pipe replacements.
As a result, rehabilitation of existing pipes is the fastest growing spend category, increasing annually from $253 million in 2019 to $576 million by 2028. Network expansions, particularly in high population growth across the sunbelt states (e.g. Texas and Arizona), will drive the lion’s share of spend on new build.
At the same tie, rising costs to address these growing needs will continue reshaping the installed material types. Well-established, large urban centers (e.g. Boston and New York) will continue to rely on traditional, legacy materials, like ductile iron, while suppliers of polymer-based pipes (e.g. PVC and HDPE) will make greater inroads on the peripheries of existing pipe networks, where developers have greater influence on procurement.
Turning to Digital
Addressing this issue of aging pipe networks is going to require a combination of increased utility spend on buried assets as well as deploying data and predicative analytics to effectively target the sections of pipe network that are most in need of rehabilitation and replacement.
The scale of investment required necessitates prioritizing rehabilitation of these aging assets and is expected to usher in more advanced asset management, such as predictive analytics. And in some cases, as we are already seeing in select cities, the opportunities for private investment, or investor-owned utilities, will increase because of these escalating costs. Irrespective of the solution, utilities are increasingly forced to do more with less — and the pipe network is no exception.
Erin Bonney Casey is a research director at Bluefield Research. She leads the company’s U.S. municipal water practice and has demonstrated experience across a range of sectors, technology applications and pressing industry topics, including wastewater management, water reuse, desalination, the cost of water and infrastructure policy and investment.
Best Suited For: Precast concrete buried structure units are well suited for applications where high compressive forces are needed for the process of installation, such as jacking and microtunneling. Shapes, such as circular, elliptical, arch and rectangular box sections allow for a variety of choices to accommodate physical obstructions that may limit available space.
Not Well Suited For: Concrete pipe is not well suited for applications having high internal pressure.
Available Diameters: Circular reinforced concrete pipe is available from 12 in. to 144 in. in diameter. Elliptical and Arch shapes are available for locations with limited vertical or horizontal clearance. These shapes have sizes equivalent to a 132-in. diameter circular pipe and less. Additionally, square and rectangular shapes are available in standard dimensions up to 12 ft by 12 ft, with larger nonstandard sizes available.
Design Life: Concrete pipe has a proven service life of more than 100 years.
Notable: Precast concrete pipe can be supplied in a variety of sizes, shapes, and strengths. When precast concrete pipe is specified and installed, there is less anxiety about conforming to product limitations and greater confidence in performing to expectations.
Source: American Concrete Pipe Association
Best Suited For: Water and wastewater pipeline installations, both gravity and pressure applications, and any installations that require a robust/strong pipe.
Ill Suited For: There really isn’t a water or wastewater pipe project where ductile iron pipe would be ill suited.
Available Diameters: 3-in. diameter through 64-in. diameter (3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 24, 30, 36, 42, 54, 60 and 64-in. diameters)
Design Life: Indefinite when properly designed and installed.
Notable: Successful trenchless installations have firmly established ductile iron pipe as a viable, and in many instances superior, pipe option. The advantages of using ductile iron pipe for trenchless installations include:
- Standard pressure capabilities up to 350 psi (greater upon special request);
- Great material strength for handling pull-back, column, and external dead and live loading;
- Better distribution of thrust or pulling forces around the bell and barrel;
- Greater allowable pulling forces than other pipe options;
- Generous allowable joint deflections;
- Quick, easy joint assembly;
- “Cartridge” installation option for limited easements or ROW;
- Can be located from surface with commonly used locators;
- Performance capabilities are not impacted by elevated temperatures;
- Material strength that does not creep or decrease with time;
- Pipe wall impermeable to volatile hydrocarbons, minimizing the potential of water system contamination in the present or future;
- A very strong pipe able to handle residual bending stresses that could adversely affect future serviceability.
- No significant “recoil” and minimal pipe movement due to thermal expansion; and
- Eliminates potential for shearing of tapped lateral outlets due to thermal expansion and contraction.
With the increasing demand for water and wastewater infrastructure and a movement to reduce the social-economic impact on rate payers that is often associated with open-cut construction, trenchless installation will certainly play an increasing role. For these installations, public works personnel and contractors have the option of installing superior ductile iron pipe.
Source: Ductile Iron Pipe Research Association
Vitrified Clay Jacking Pipe (VCP-J)
Best Suited For: Gravity flow sanitary sewers.
Ill Suited For: Pressure applications.
Available Diameters: 8 to 24 in. ID.
Design Life: 200-plus years.
Notable: VCP-J is the predominant small diameter direct-jacked product pipe material due to its unmatched compressive strength (18,000 psi average), low-profile, zero-leakage joint and proven unmatched service life. Vitrified clay is a fired ceramic with material properties unaffected by age, light or chemicals. It provides unmatched durability to aggressive cleaning tools and techniques. Today’s vitrified clay jacking pipe coupled with trenchless installation methods allow municipalities to design, construct and maintain the most sustainable collection systems of this century.
Source: National Clay Pipe Institute
High Density Polyethylene (HDPE)
Best Suited For: Potable water services, distribution and transmission, reclaimed water, sewer (force main, gravity, storm), industrial, nuclear, power (electrical and communication) and gas. This summary will focus on HDPE solid wall for water and sewer.
Ill Suited For: Pressure applications with annual average temperature exceeding 140 F and Pressure Class exceeding 335 psi.
Available Diameters: 3/4 in. to 65 in.
Design Life: Properly designed, installed, inspected and operated HDPE piping systems have a minimum design life of 100 years.
Notable: Properly designed and installed HDPE pipes and HDPE joints have the lowest failure rate, zero allowable leakage, lowest initial and life cycle costs, inherent corrosion resistance, longest design life, longest fatigue life and are the preferred material for trenchless installations. Also, due to high ductility, HDPE water piping systems had zero failures in the last five earthquakes in Japan, Chile and New Zealand.
Source: Plastics Pipe Institute Inc.
Best Suited For: For sanitary sewer or industrial sewer service where conditions require corrosion protection.
Ill Suited For: Currently, polymer concrete pipe is not designed for or approved for pressure of potable water
Available Diameters: Polymer concrete pipe is available in diameters ranging from 8 to 144 in.
Design Life: Polymer concrete pipe has a projected 100-year plus service life.
Notable: “In choosing a pipe material, owners have found that polymer concrete pipe, with its unique physical properties, combines the best attributes of the leading pipe materials- inherent corrosion resistance of FRP pipe along with the rigid properties of reinforced concrete pipe. Years back when we first introduced the reinforced polymer concrete pipe to the market, we often described polymer concrete pipe as a hybrid to those unfamiliar with the product. Nowadays, everyone is much more familiar with polymer concrete and our product availability has increased significantly even in the last couple years with added production capacity in North America,” says Mike Olson, Interpipe Polymer/PolymerCrete.
Source: Interpipe Polymer/PolymerCrete
Polyvinyl Chloride (PVC)
Best Suited For: Potable water, reclaimed water, sewer force main, gravity sanitary sewer, and storm sewer pipe and fittings.
Ill Suited For: Temperature applications where fluid conveyed is consistently greater than 140 F or high-pressure applications consistently above 305 psi.
Available Diameters: Gasketed PVC pressure pipe is available is sizes from 4 to 60 in. Gasketed PVC gravity sewer pipe is available from 3 to 60 in.
Design Life: Studies confirm that PVC pipe lasts in excess of 100 years.
Notable: PVC water and sewer pipe has been in service in North America for almost 70 years, with more than 2 million miles installed. According to a 2018 Utah State University report, PVC pipe has the lowest break rate of all commonly used pipe materials in the U.S. and Canada.
Source: Uni-Bell PVC Pipe Association
Fiberglass Reinforced Pipe
Best Suited For: Potable water transmission, force main or gravity sewer systems and all applications where there is a corrosive carrier or external environment.
Ill Suited For: Really not a water or wastewater project in which fiberglass reinforced pipe would be ill suited.
Available Diameters: The pipe is available from 18 to 158 in. in diameter.
Design Life: In excess of 100 years.
Notable: The United States increased application of sliplining and pipe jacking that enables public utilities to maintain their sewage system operation requires a corrosion resistant pipe that can accomplish high push-loading. In addition, there is an increased application of microtunneling, pipe bursting and directional drilling where fiberglass pipe and manway manufacturers are providing a corrosion resistant alternative to traditional pipe materials. The Fiberglass Tank & Pipe Institute represents the following manufacturers of pipe and manways listed alphabetically: Containment Solutions Inc., NOV Fiber Glass Systems, Hobas Pipe USA and L.F.Mfg. The Institute website fiberglasstankandpipe.com maintains a direct link to these manufacturers.
Source: Fiberglass Tank & Pipe Institute
Best Suited For: Water and wastewater transmission, gas and oil transmission, water well casing, pile driving and caisson sleeves.
Ill Suited For: Chemical or corrosive service without internal or external protective coatings.
Available Diameters: Steel pipe is available in diameters 4 in. and larger with virtually an unlimited choice of fitting and special fabrications possible.
Design Life: The design life of steel pipe is based on the mechanical strength of steel which is fully elastic and not time dependent. If properly installed, with the appropriate lining and coating, steel pipe with the addition of electrical bonding and cathodic protection (if required) can last indefinitely.
Notable: The performance resume for steel pipe dates back to the early 1850s. This experience in pressure applications for water, gas and petroleum fluids cannot be matched by any other pipe material, particularly those made from plastic materials that are visco-elastic, where the material strengths erodes overtime. Steel pipe, with its simple, straight-forward design procedure and pragmatic installation requirements, is finding its way into project specifications once dominated by pipes of composite construction. STI/SPFA member companies are certified for the SPFA Certification program by Lloyd’s Register Quality Assurance. This provides owners and engineers with assurance that their steel pipe is manufactured in strict accordance with applicable AWWA, ASTM and other standards and industry accepted practices.
Source: Steel Tank Institute/Steel Plate Fabricators Association (STI/SPFA)