The 2012 edition of the Uniform Plumbing Code (UPC©) represents the most current approaches in the plumbing field. It is the fourth edition developed under the ANSI Consensus process is designated as an American National Standards by the American National Standards Institute (ANSI). Contributions to the content of this code were made by every segment of the built industry, including such diverse interests as consumers, enforcing authorities, installers/maintainers, labor, manufacturers, research/standards/ testing laboratories, special experts and users.
The UPC is designed to provide consumers with safe and sanitary plumbing systems while, at the same time, allowing latitude for innovation and new technologies.
Key changes to the 2012 UPC include new provisions for alternative water sources for nonpotable applications, rainwater catchment systems, plumbing facilities, and joining methods for water supply and drainage piping.
Chapter 4 has been significantly improved through reorganization in the area of plumbing fixtures by expanding their use and application, water consumption and installation requirements. For example, a recommendation for approval as modified for showers that incorporated their application to applicable referenced standards includes water consumption requirements for a maximum flow rate in accordance with ASME A112.18.1/CSA B125.1. An added provision reduces the risk of scalding by requiring individual and tub-shower control valves to provide such protection based on the flow rate of the showerhead be installed at the point of use. The addition of required waste outlet sizing, referencing material and sizing provisions, and the removal of the requirement for a finished dam curb or threshold to aid the aging population, are among changes aimed at providing ease of use for the end user.
Required plumbing fixtures is revised based on research conducted by ASPE, the Stevens Institute of Technology, the American Restroom Association and the School of Architecture with the Gender and Women’s studies program at the University of Illinois (Potty Parity in Perspective: Gender and Family Issues in Planning and Designing Public Restrooms). When designing satisfactory restroom facilities, factors that are considered to decide the minimum number of plumbing fixtures for a preferred service include occupancy, waiting times during peak demand, fixture use and the likelihood of finding a vacant fixture. Potty parity does not always mean there will be the same number of toilets for women and men; parity is measured by the wait time to obtain a fixture. Where we see the most inconsistency occurs in the number of required plumbing fixtures for women and men in mercantile and assembly occupancies that use the same ratio for both sexes. The 2012 UPC recognizes that women need more time, and the minimum required fixtures should accurately represent the population served based on design method.
Chapters 6 and 7 now offer various joining methods and connections to aid the end user in identifying correct methods based on the piping material. The material covered for water supply and water distribution joining methods includes: asbestos cement, brass, copper, CPVC, ductile-iron, PE, PE-AL-PE, PE-RT, PEX-AL-PEX, PP, PVC and stainless steel. The material covered for drain, waste and vent piping joining methods includes: ABS, asbestos-cement, cast-iron, co-extruded ABS, co-extruded PVC, copper, PE, PVC, stainless steel 304, stainless steel 316L and vitrified clay. Step-by-step guidance provides the user with clarification on acceptable methods of connection to piping materials.
Significant changes apply to Chapter 16 (“Alternate Water Sources for NonPotable Applications”) by expanding the scope with alternate water sources and developing code provisions that are specific to each one. The three areas addressed in Chapter 16 are gray water sources, reclaimed (recycled) water sources and on-site treated nonpotable water systems. The new water sources include three types of water disposal: subsurface irrigation, subsoil irrigation and mulch basin systems. Subsoil water irrigation provides a means to disperse shallow drip irrigation lines and mulch basins that collect and spread water in single- and multi-family dwelling applications. The reclaimed water provisions to on-site nonpotable water systems include gray water and other nonpotable water sources that are used for on-site applications. They are unique by installation through prepackaged or engineered systems that are listed and labeled for the intended application.
Chapter 17 is a new chapter dedicated to nonpotable rainwater catchment systems that includes input from the American Rainwater Catchment System Association. This chapter covers irrigation, toilet and urinal flushing with proper treatment; provisions where permits are required, maintenance of alternate water sources; and minimum water quality.
Two new appendices cover potable rainwater catchment systems that include operation and maintenance requirements, minimum water quality, material compatibility, controls, backflow prevention, design and installation requirements and sustainable construction practices for plumbing systems as a resource for the Authority Having Jurisdiction.