More and more buildings in the multi-family housing sector are converting to systems where each multi-family dwelling unit pays for water and wastewater directly instead of including these charges as part of the rent. The three most common ways in which separate billing is accomplished are: (1) Through direct submetering of water use by means of a water meter installed on a single or multiple points of entry water line(s); (2) Through a Ratio Utility Billing System (RUBS), which bases the water bill on an allocation formula that uses floor space, number of occupants, etc.; or (3) A hybrid of the two where total water use is estimated based on the ratio of metered hot (or cold) water use (and sometimes selected appliances) in a unit to the total water use of all occupants. It is estimated that there are now more than 1.2 million apartment renter households that are billed separately for water and sewer using one of these billing system methods (NMHC 2001).

RESEARCH OBJECTIVES
The goals of the National Multiple Family Submetering and Allocation Billing Program Study were to determine the merits of separate billing programs including the potential water savings, costs and benefits from various perspectives, and the accompanying administrative and regulatory issues. In the study, a retrospective analysis of water use in multi-family properties in 13 cities was conducted. The 13 study cities were weighted towards the West and southwestern region of the United States, but contain a wide variety of utilities serving a broad and diverse group of customers. Properties equipped with submeters or that have undergone a billing system conversion (impacted properties) were identified and compared against control (in-rent) properties where water and wastewater fees are included as part of the rent. The study compared the two groups using historic billing data provided by participating water utilities combined with an extensive series of mail surveys and site visits. The data collected for study provides a wealth of information about how submetering and allocation affect water use, property owners, and residents. Embedded in these data are insights into this developing industry, including the quantitative aspects of separate billing. The data are also useful for examining the impacts of the 1992 Energy Policy Act plumbing standards and other factors that may influence water use. It is anticipated that the database of submetered and allocated billing program information developed for this study will be a resource for researchers and planners to explore for years to come, particularly if it is maintained and updated.

Download the Final Report: (pdf format)

Two versions of the final report are available for free download as well as the exectutive summary and the study press release..

Full final report (6.4 mb)
Final report without appendix (2.5 mb)
Executive Summary only (0.4 mb)
Press Release (0.1 mb)

Team: The project team for the National Multiple Family Submetering and Allocation Program Study combined tremendous expertise in water resources data collection and analysis, survey design and implementation, statistical sampling, statistical analytical methods, cost/benefit analysis, and policy evaluation. Team members included:

Aquacraft, Inc. - Water Engineering and Management
Founded in 1990, Aquacraft specializes in water demand planning and management. Aquacraft's primary focus is researching and evaluating water use patterns of municipal customers, and collecting and analyzing data that can be used to tackle a broad range of water planning and management issues. Aquacraft pioneered the use of flow trace analysis to measure how water is used in a variety of urban settings. Aquacraft has developed large databases of disaggregated water use, customer billing, and demographic information from both the residential and commercial sectors. Aquacraft is a recognized national leader in evaluating the effectiveness of water conservation measures for reducing long-term water demands. Located in Boulder, CO.

National Research Center, Inc.
National Research Center, Inc. (NRC) is one of the leading survey research and strategic planning teams in the United States, focusing on the information and evaluation needs of the public and non-profit sectors. NRC principals have worked more than 20 years on issues in critical areas such as transportation, land use, water use and conservation, special needs human services, law enforcement, libraries, parks, recreation, recycling, health care, customer satisfaction and more. NRC has extensive experience in conducting research using a variety of data collection approaches (by phone, by mail, in-person, by observation, etc.). NRC has performed a variety of statistical data analyses, using data obtained from a wide array of sources, including surveys, observations, or secondary data sources. NRC usually use SPSS to perform data analysis. Located in Boulder, CO.

Dr. Peter J. Bickel:
Professor of Statistics, Department of Statistics,University of California, Berkeley, Dr. Bickel is one of the pre-eminent statisticians in the world today. He is chair of the Board on Mathematical Sciences for the National Research Council, a member of the National Academy of Sciences since 1995, a member of the Board of Trustees for the National Institute of Statistical Sciences since 1992, and a 1984 winner of a John D. and Catherine T. MacArthur Foundation Fellowship. He has served as a statistical consultant to the EPA, Lawrence Berkeley Laboratory, Nevada State Gaming Control Board, and the State of California Department of Human Services.

Ed Osann, President of Potomac Resources, Inc.:
President of Potomac Resources, Inc. Ed formerly served as Director of Policy and External Affairs for the Bureau of Reclamation, the water and power agency within the U.S. Department of the Interior, from 1993 to 1995. Prior to joining the federal government, Ed served as Director of the Water Resources Program of the National Wildlife Federation from 1980 to 1993. He established a consulting practice specializing in energy and natural resources policy in Washington in 1996. Clients have included water and wastewater utilities, foundations, environmental organizations, and companies that provide energy- or water-saving products or services. Located in Washington, DC.

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