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    IAPMO RESEARCH

    Whitepapers & Studies

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    IAPMO research provides strategic insights to advance policy on clean drinking water and safe sanitation. Instead of simply looking at a problem, our staff and members — many times in partnership with communities or other professional organizations — study and research issues affecting health and environmental impacts of changing plumbing, mechanical, alternative energy, and water systems, and how they affect our daily lives. In many cases, there are unintended consequences that also require consideration in developing optimal solutions. IAPMO believes in sharing our knowledge through industry studies and whitepapers, because safety belongs to everyone.

    50th Annual CIB W-062 Conference Proceedings August 25 – 27, 2025

    Article Source: CIB  
    The following page references identify sections featuring contributions from IAPMO, along with authors from other organizations.

    • [Page 73] San Francisco Accelerates Implementation of Onsite Water Reuse in USA; Dan Cole (IAPMO), Taylor Nokhoudian (San Francisco Public Utilities Commission)
    • [Page 272] A Review of Water Use Data Collected in Hotel Building to Extend the Application of the Water Demand Calculator®; Toju Omaghomi, PhD. (IAPMO); Christoph Lohr, PE (IAPMO); Dan Cole (IAPMO)
    • [Page 305] Improving Domestic Hot Water Recirculation Sizing Using Hardy-Cross and Product Ratio Methods; Christoph Lohr, PE (IAPMO)
    • [Page 408] The Impact of velocity, pipe type, and use frequency on water quality; Tim Bartrand PhD.(IAPMO-ESPRI); P.L. Gurian (Drexel University); Mike Cudahy (PPFA)
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    Peak Water Demand Study: Full Study

    IAPMO and ASPE, along with funding from the Water Quality Research Foundation (WQRF), convened a special task force to revise the methodology for properly estimating premise water supply demands in response to the increased use of water-conserving plumbing fixtures, fixture fittings and appliances and the subsequent decreased demand for water in commercial buildings and residences. The charge of the task group was to develop a statistically based probability model that would predict the peak water demand for single and multi-family dwellings having water-conserving plumbing fixtures.

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    Adaptive Reuse: Converting Offices to Multi­Residential Family

    Adaptive reuse of commercial office spaces to residential multifamily offers opportunities to ease some of the housing shortage in the US. These types of construction projects have many challenges, from zoning restrictions, financing, and also controlling construction costs. Construction costs specifically can have a disparate impact on whether an adaptive reuse project is possible, let alone successful. Therefore, flexibility during the construction process is vital to the success of an adaptive reuse project. Codes for plumbing and mechanical systems that support design versatility and science-based methods, such as the Uniform Codes, will be essential for controlling construction expenses.

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    Capacities of Stacks and Horizontal Drains in Storm Drainage Systems

    The sizing for storm drainage systems are dependent upon flow capacity equations used to calculate velocities and flow rates in pipe conduits. One of the variables in the equations is the coefficient of roughness. This paper explores how the roughness of different types of material will change the computational results that are dependent upon the roughness coefficient of the pipe.

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    Increase in Flow Diversity From Simultaneous Fixture Use: Impact on Peak Flow Estimate

    In calculating peak water demand, there can be instances where an increase in fixture count results in a decrease in the expected peak demand. This white paper explains why this counterintuitive result can occur, especially when there is some probability of stagnation (i.e., zero demand). Using IAPMO’s Water Demand Calculator (WDC), we are not designing with zero flow in mind; hence, zero flows are ignored, and the 99th percentile is extracted from actual flows for any combination of busy fixtures.

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    RESEARCH ARCHIVE

    Eliminating lead exposure from drinking water—A global call to action

    Article Source: PLOS Water
    Each year, approximately 900,000 people die from exposure to lead. But the full impacts of lead exposure are far more insidious. Lead is a potent neurotoxin that impairs brain function and irreversibly harms children’s cognitive development. Any exposure to lead can be damaging. Recent studies estimate that 800 million children globally (approximately 1 in 3) have blood lead concentrations above 5 micrograms per deciliter and that lead exposure may be responsible for 30% of all intellectual disabilities of unknown origin.

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    Energy and Carbon Savings Opportunities

    Arup was commissioned by IAPMO to analyze the Water Demand Calculator (WDC) developed by IAPMO to better understand its potential for energy and embodied carbon savings. This energy and embodied carbon savings analysis compared the Water Demand Calculator with the Hunters Curve method included in the International Plumbing Code (IPC) and Uniform Plumbing Code (UPC) for sizing domestic hot water systems in four residential use cases. Currently, the WDC is available for use in UPC Appendix M, WE•Stand, and as a standalone document.

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    Lead in drinking-water: Health risks, monitoring and corrective actions

    Article Source: The World Health Organization
    Lead is a priority chemical hazard that should be included in national drinking-water quality standards and monitored as part of drinking-water quality surveillance. This document provides practical guidance to support the assessment and management of lead contamination in drinking-water supplies. Step-wise guidance is provided to support action when elevated lead concentrations are detected in drinking-water. It also explains why lead in drinking-water is an important issue and sources of lead exposure in water supplies.

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    Reforming National and State Policies to Reduce Inequity of Safely Managed Sanitation in the United States

    Article Source: DIGDEEP
    The Decentralized Wastewater Innovation (DWI) Cohort is a nationwide community-driven research initiative by DigDeep Right to Water Project elevating decentralized wastewater challenges, solutions, and policy opportunities. Given the unique intersection of (1) unprecedented federal funding for decentralized and alternative wastewater solutions, (2) the complex landscape of residential infrastructure needs, and (3) the diverse, comprehensive expertise of the DWI Cohort.

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    Water and Sanitation Standards in Southeast Asia Considerations for ASEAN Member States

    Worldwide, 2.2 billion people lack access to safe drinking water, and more than half of the global population does not have access to safe sanitation. Access to water and sanitation services is further threatened by growing water stresses. Approximately 2.3 billion people live in water-stressed countries, of which 733 million live in high and critically water-stressed countries. This global water crisis threatens economic growth, national security, and public health.

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    Water and Sanitation Standards in Southeast Asia A Guide for U.S. Manufacturers and Exporters

    There is a growing global water crisis that threatens economic growth, public health, and national security, and generally reduces the capacity of countries to advance important national priorities. Public and private stakeholders in the United States have an important role to play in addressing these challenges, providing technologies and policy solutions that will contribute to a healthier, safer, more water-secure world where people have sustainable supplies of water of sufficient quantity and quality.

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    Reaching those left behind: knowledge gaps, challenges, and approaches to achieving SDG 6 in high-income countries

    Article Source: IWA Publishing
    Even as progress has been made in extending access to safe water and sanitation under the Sustainable Development Goals (SDGs), substantial disparities in water, sanitation, and hygiene (WASH) services persist in high-income countries around the world. These gaps in service occur disproportionately among historically marginalized, rural, informal, and Indigenous communities.

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    A Review of Connection Fees and Service Charges by Meter Size

    Right-sizing premise plumbing systems has become a prominent topic of discussion in the plumbing and water industries, for good reason. Supply line and pipe sizing methodologies have been largely unchanged since Hunter’s Curve was created by Roy B. Hunter in 1940 -- yet fixtures and appliances such as faucets, showerheads, toilets, clothes washers, and dishwashers operate much more efficiently than they did in 1940 and thus have slowed the flows. Unfortunately, it is still common for meters and supply and waste lines to be oversized according to Hunter’s Curve. These oversized premise plumbing systems create multiple inefficiencies and worse, can have a negative impact on water quality.

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    Studies Detail the Cost Saving Potential of the Water Demand Calculator

    There is a tremendous need for practical, water-related demand-side water research that helps communities safely implement policies related to water and energy efficiency and meet the growing list of challenges threatening drinking water quality in the United States. Profound concerns about water safety and wasted water and energy resulting from oversized water supply pipes in home and buildings, motivated IAPMO to lead a research project along with the American Society of Plumbing Engineers (ASPE), the Water Quality Research Foundation (WQRF), and the University of Cincinnati, to develop a new statistically based pipe sizing method.

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    Stantec Cost Report

    Stantec Architecture Inc. was commissioned by IAPMO to develop a prototype Single Family Residence plumbing plan, a 6-Unit Family Residence plumbing plan, and a 45 – Unit Family Residence plumbing plan in order to compare the cold and hot water sizing criteria associated with IAPMO’s – Water Demand Calculator (WDC) to the sizing methods contained within the Uniform Plumbing Code (UPC) the International Plumbing Code (IPC) and the International Residential Code (IRC).

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    Recommended Installation Practices for Residential Tankless Water Heaters to Reduce the Danger of Scalding

    The ASSE International Scald Awareness Task Group was formed to educate and give guidance to the general public and plumbing industry on scald hazards associated with hot water. This white paper focuses on the recommended installation practices that plumbers, installers, and/or plumbing contractors should follow to reduce the dangers of scald injuries or thermal shock when installing any type of residential tankless water heater.

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    Closing the Water Access Gap in the United States

    Article Source: DIGDEEP
    Access to clean, reliable running water and safe sanitation are baseline conditions for health, prosperity, and wellbeing. However, they remain out of reach for some of the most vulnerable people in the United States: communities of color, lower-income people in rural areas, and tribal communities, among others. Today, more than two million Americans lack access to running water, indoor plumbing, or wastewater services. Better water access would allow vulnerable communities to thrive.

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    Recommended Installation Practices for Residential Storage Type Water Heaters to Reduce the Danger of Scalds

    The ASSE International Scald Awareness Task Group was formed to educate and give guidance to the general public and plumbing industry on scalding hazards associated with hot water at the point of use. This White Paper will focus on the recommended installation practices for residential storage type water heaters that the plumber, installer or plumbing contractor should follow to reduce the dangers of scald injuries at the point of use which is the plumbing fixture such as showers, bathtubs, lavatory faucets, and kitchen faucets.

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    Peak Water Demand Study: Executive Summary

    IAPMO and ASPE, long with funding from the Water Quality Research Foundation (WQRF), convened a special task force to revise the methodology for properly estimating premise water supply demands in response to the increased use of water-conserving plumbing fixtures, fixture fittings and appliances and the subsequent decreased demand for water in commercial buildings and residences. The charge of the task group was to develop a statistically based probability model that would predict the peak water demand for single and multi-family dwellings having water-conserving plumbing fixtures.

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    The Drainline Transport of Solid Waste in Buildings – Phase 2.0

    Potential blockages in commercial building drain lines have been feared by plumbers and building managers due to increasingly efficient plumbing fixtures. The Plumbing Efficiency Research Coalition (PERC) identified this issue as a critical research need, and undertook an earlier phase of this study to examine the behavior of drain lines under certain conditions. This report is the second part of that study evaluating the characteristics of transport of solid waste in commercial building drains.

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    The Drainline Transport of Solid Waste in Buildings

    Article Source: Plumbing Efficiency Research Coalition
    With the enactment of the Energy Policy Act of 1992, all water closets (toilets) manufactured in or imported into the United States were required to flush no more than a maximum average of 1.6 US gallons (6.0 Liters), effective January 1, 1994 for residential models and January 1, 1997 for all other models. After these new models were introduced into the marketplace, a significant number of consumers reported poor flush performance. This prompted some early reporting and research on the first generation of 1.6 gallons per flush (gpf) (6.0 Liters per flush – Lpf) water closet models.

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    Storm Drainage System Research Project

    Article Source: Florida Building Commission
    It was brought to the attention of the American Society of Plumbing Engineers Research Foundation (ASPE RF) that a number of failures with storm drainage systems had occur red. The types of failures included: Collapse of roof Pipe fitting separating Hanger pulled from prestressed concrete floor/ceiling Flooding of upper-level balcony decks Fitting component failure Flooding in the building on upper floors due to pipe failure.

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    EPA Decentralized Plumbing Webinars

    EPA's Decentralized Wastewater Management Memorandum of Understand (MOU) Partnership sponsors periodic webinars to discuss issues of interest to the decentralized community. Below are presentations, transcripts, and speaker lists from each of the webinars.

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