**1. Introduction**

420 Corrosion Resistance

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Consumers' decisions on plumbing material selection are dictated by various factors, including state and federal regulations, service providers, and individual household preferences. The regulations and standards of the federal, state, and local governments have major impacts on the plumbing material chosen for installation in a private house. For example, the use of plastic plumbing material, such as PEX, has been approved in all U.S. states except for California and Massachusetts, where the material installation requires local jurisdiction acceptance. Similarly, in some parts of Florida, PEX is preferred due to the seriousness of pinhole leak1 problems (NSF, 2008). These regulations influence services provided by plumbers, material producers (e.g. pipe manufacturers, interior coating providers), and water utility companies. For example, general contractors are the primary decision-makers of plumbing material installation in new houses, while utility companies respond to corrosion threats by adding corrosion inhibitors to drinking water treatment. Consequently, all service providers influence consumer decisions, regarding the best plumbing material for private properties.

Homeowners have an important stake in finding plumbing system appropriate for their households, and they should rely not only on expert advice, but also acquire information on plumbing material attributes such as price, health impact, longevity, and corrosion resistance, in order to make informed investment decisions about plumbing systems for their homes. For example, health effects, water taste and odor have been found to be the most important factors in consumers' evaluations of plumbing material for home use (Lee et al., 2009). Additionally, households are willing to pay up to \$4,000 when guaranteed a leakfree plumbing system for 50 years (Kleczyk et al., 2006). Information on consumer preferences for drinking water plumbing attributes can be useful not only to individual households, but also to policymakers, program managers, water utilities, and firms with interests in drinking water infrastructure.

<sup>1</sup> Pinhole Leaks are a small holes that commonly are caused by pitting corrosion, a type of corrosion concentrated on a very small area of an inner pype. In most cases, pinhole leaks are hard to detect, if they are visible, they appear as green, wet area on pipe and porcelain fixtures (Kleczyk & Bosch, 2008).

Households' Preferences for Plumbing Materials 423

To make an informed decision about the optimal plumbing material for their home, homeowners need information on the various risks involved in choosing plumbing systems. When informed about the plumbing material characteristics, the consumers are able to decide on an alternative most preferable to them based on the preference trade-offs among plumbing materials' attributes. Households make decisions on a plumbing alternative when either replacing an existing system or installing a plumbing system in a new house. Each alternative has advantages and disadvantages that impact health and the overall cost of installation and maintenance. The problem becomes more complex as consumers think in terms of cost (material plus labor charges), taste and odor of the water, corrosion problem, longevity of the pipe system, fire retardance, convenience of installation or replacement, plumbers' and general contractors' opinions or expertise, and proven record in the market. Householders weigh each of these attributes in order to choose the most preferred option for

For example, Lee et al. (2005), utilizing the AHP method, studied the preferences for plumbing materials of Virginia Tech potable water experts. Participants ranked the health effects, reliability, taste and odor, and longevity as the most important attributes when choosing a plumbing material. Property value and fire resistance were listed at the bottom of the ranking. These results showed that health, water taste and odor dominate preferences for plumbing materials. Lack of reliability resulting in the need to repair the damage associated with pipe corrosion relates to stress and a worry about future leaks (Lee et al.,

There are several plumbing material types for a householder to choose from when deciding on a plumbing material to be installed in a house: copper, plastic (CPVC and PEX), and stainless steel. According to Marshutz' survey (2000), copper is used in nearly 90% of homes in the U.S. followed by PEX (cross linked polyethylene) with a 7% installation rate, and CPVC (chlorinated polyvinyl chloride) with a 2% installation rate. Telephone surveys of plumbers conducted in 2005 show an increased use of plastic pipes, due to easier handling

Copper is the most widely used material in residential plumbing and has several advantages, including affordability, fire resistance, few health hazards, and durability. Woodson (1999) studied the performance of different plumbing material alternatives: copper, CPVC, and PEX. He found copper pipes generally perform well, except for cases involving major leak problems (Woodson, 1999). Due to increased pinhole leak incidents reported in hotspot areas of the U.S. (eg. Washington, D.C. suburbs and Sarasota, Florida), many consumers replaced copper with other options. Concerns with copper pipes include a metallic taste, especially with long stagnation periods and increased absorption of residual disinfectant by the pipe walls. High levels of copper can cause nausea, vomiting, and diarrhea (ATSDR, 2004). Elevated copper levels in drinking water may increase lead levels when lead solder joints, lead service lines, or brass fixtures are present in plumbing material. It is advised to test for lead when testing for copper levels in drinking water as lead and

PEX (polyethylene cross linked) is another type of plumbing material often used in residential plumbing. This material is used to make flexible plastic pipes. A different plumbing design characterized by individual pipe lengths is required for every fixture. The

in installation and lower material cost (Scardina et al., 2007).

copper enter drinking water under similar conditions (Lee, 2008).

their houses (Lee et al., 2009).

2005).

The public perceptions of corrosion risk and cost of prevention play a fundamental role in consumers' drinking water decisions. Homeowners' perceptions of risk and cost of prevention may affect households' decisions on plumbing material repairs and replacement, as well as the type of material used. When informed about the attributes of each plumbing material alternative, consumers can decide on the most preferred plumbing system. The decision of choosing an appropriate plumbing material is based on various plumbing material attributes, such as cost (material cost plus labor and installation cost), health effects, corrosion susceptibility, strength, property real estate values, and behavior in the case of a fire (Champ et al., 2003).

As it is important to learn household perceptions and preferences for drinking water infrastructure, the chapter objective is to investigate homeowners' preferences for plumbing materials (i.e. copper, plastic, an epoxy coating), as well as preventive techniques against corrosion based on households' experiences with plumbing material failures. In 2007, a survey of a Southeastern Community in the United States was conducted in order to meet these goals, and obtain information on the prevalence of plumbing material failures, householders' experiences with plumbing material failures, the cost of repairs and property damages due to the material failures, and household preferences for plumbing systems.

The objective of the study is fulfilled by analyzing in-depth the information of the prevalence of home plumbing corrosion, preventive measures taken against corrosion, as well as the financial, health, and time costs associated with repairing faulty plumbing systems. In addition, analyses are performed to elicit household preferences for plumbing materials, and to identify the attributes important to choosing home plumbing systems. Summary statistics as well as regression methods, such the Ordered Logit model, are employed to support the study, and provide insight into the scale of corrosion in the community, the financial burden accrued from repairing the problem, and finally recommendation for the best plumbing materials for household use.

The knowledge gained from this chapter can be helpful in the design of public policy aimed at corrosion prevention. The research provides information to federal and state officials, plumbers, plumbing material manufacturers, and utility company managers on the financial burden individual households are willing to take on to avoid corrosion. In addition, the study should help in bridging the gap between the perceptions of the public and drinking water infrastructure experts, regarding the problem of pinhole leaks and other corrosion related issues.
