Water Infrastructure: Water-Efficient Plumbing Fixtures Reduce Water
Consumption and Wastewater Flows (Letter Report, 08/31/2000,
GAO/RCED-00-232).
Pursuant to a congressional request, GAO provided information on the
impact of the national water efficiency standards, focusing on: (1) the
estimated impact of the national water efficiency standards on water
consumption levels and wastewater flows; and (2) how repealing the
national standards might affect projected investments in drinking water
and wastewater treatment infrastructure, state and local governments'
ability to finance their infrastructure needs, and the likelihood of
moratoria on new residential and commercial construction if the demand
for water is unabated.
GAO noted that: (1) no studies estimating the impact of the national
water efficiency standards on water consumption or wastewater flows
nationwide have been completed; (2) however, studies designed to measure
the impacts of using water-efficient plumbing fixtures in specific
locations have shown that, compared with their less efficient
counterparts, low-flow fixtures conserve water, particularly in the case
of toilets; (3) a comprehensive study of water use in nearly 1,200 homes
with low-flow toilets showed that the toilets used about 40 percent less
water for flushing than other homes in the study; (4) estimating the
impact of the national standards is difficult because some use of
low-flow fixtures would likely occur for other reasons--that is, even in
the absence of the standards; (5) these reasons include: (a) state and
local laws that preceded the national standards; and (b) incentives,
such as rebate programs sponsored by local governments, that encourage
the replacement of less efficient fixtures; (6) nevertheless, major
studies initiated by the American Water Works Association and the
Environmental Protection Agency are developing long-term projections of
the nationwide impact of the water efficiency standards, using precise
measurements of the water savings per fixture as a starting point and
taking into consideration expected population growth, the average
replacement rate for plumbing fixtures, and other data; (7) preliminary
results indicate that by 2020, water consumption could be reduced by
about 3 to 9 percent, depending on the location, and wastewater flows to
publicly owned treatment works could be reduced by an estimated 13
percent nationwide by 2016; (8) although, their precise impact is
uncertain, repealing the national standards could affect the extent to
which reductions in water consumption and wastewater flows are achieved
and, thus, limit the extent to which local communities' investments in
drinking water or wastewater infrastructure can be deferred or avoided;
and (9) repealing the national water efficiency standards could
exacerbate the financial pressures facing local communities by forcing
them to build or expand treatment and storage facilities sooner than
planned.
--------------------------- Indexing Terms -----------------------------
REPORTNUM: RCED-00-232
TITLE: Water Infrastructure: Water-Efficient Plumbing Fixtures
Reduce Water Consumption and Wastewater Flows
DATE: 08/31/2000
SUBJECT: Water conservation
Wastewater management
Water supply management
Standards and standardization
Cost control
Potable water
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GAO/RCED-00-232
Appendix I: Evolution of Required Performance Tests for
Low-Flow Toilets
26
Appendix II: Preexisting State and Local Standards for
Water-Efficient Plumbing Fixtures and Their Status
If National Standards Were Repealed
29
Appendix III: Summary of Accelerated Toilet Replacement
Programs in Six Localities
31
Appendix IV: Projected Reduction in Water Consumption by
2010 and 2020, by Location
32
Appendix V: Projected Investments in Drinking Water Infrastructure
by the Year 2020, by Location
34
Appendix VI: Scope and Methodology
35
38
Table 1: National Water Efficiency Standards 6
Table 2: Water Use by Type of Toilet 10
Table 3: Reported Savings Attributable to Low-Flow Toilets
in Studies Using Precise Measurements 11
Table 4: Evolution of Industry Testing Requirements for Low-Flow
Toilets 27
Table 5: State and Local Standards for Water-Efficient Plumbing
Fixtures 29
Figure 1: Mean Daily Residential Water Use at 12 Study Sites 9
Figure 2: Percentage of Water Savings by Location 17
EPA Environmental Protection Agency
GAO General Accounting Office
Resources, Community, and
Economic Development Division
B-285890
August 31, 2000
The Honorable Michael Bilirakis
Chairman, Subcommittee on Health and Environment
Committee on Commerce
House of Representatives
The Honorable Sherwood L. Boehlert
Chairman, Subcommittee on Water Resources
and Environment
Committee on Transportation
and Infrastructure
House of Representatives
Water-efficient plumbing fixtures, such as low-flow toilets and showerheads,
first became generally available to American consumers in the late 1980s.
Subsequently, under the Energy Policy Act of 1992, the Congress established
uniform national standards for the manufacture of these fixtures to promote
conservation by residential and commercial water users. The act also
preempted state and local authorities from setting different standards.
Proposed legislation filed in 1999 would have repealed the national
standards and eliminated the act's preemptive language.
Concerned about the potential implications of the proposed legislation, you
asked us to examine the impact of the national water efficiency standards.
Specifically, you asked us to provide information on (1) the estimated
impact of the national water efficiency standards on water consumption
levels and wastewater flows and (2) how repealing the national standards
might affect projected investments in drinking water and wastewater
treatment infrastructure, state and local governments' ability to finance
their infrastructure needs, and the likelihood of moratoria on new
residential and commercial construction if the demand for water is unabated.
No studies estimating the impact of the national water efficiency standards
on water consumption or wastewater flows nationwide have been completed so
far. However, studies designed to measure the impacts of using
water-efficient plumbing fixtures in specific locations have shown that,
compared with their less efficient counterparts, low-flow fixtures conserve
water, particularly in the case of toilets. The best example is a
comprehensive study of water use in nearly 1,200 homes at 12 study sites
that determined, among other things, that homes with low-flow toilets used
about 40 percent less water for flushing than other homes in the study.1
Estimating the impact of the national standards is difficult because some
use of low-flow fixtures would likely occur for other reasons--that is, even
in the absence of the standards. These reasons include (1) state and local
laws that preceded the national standards and (2) incentives, such as rebate
programs sponsored by local governments, that encourage the replacement of
less efficient fixtures. Nevertheless, major studies initiated by the
American Water Works Association and the Environmental Protection Agency
(EPA) are developing long-term projections of the nationwide impact of the
water efficiency standards, using precise measurements of the water savings
per fixture as a starting point and taking into consideration expected
population growth, the average replacement rate for plumbing fixtures, and
other data. Preliminary results indicate that by 2020, water consumption
could be reduced by about 3 to 9 percent, depending on the location, and
wastewater flows to publicly owned treatment works could be reduced by an
estimated 13 percent nationwide by 2016.
Although their precise impact is uncertain, repealing the national standards
could affect the extent to which reductions in water consumption and
wastewater flows are achieved and, thus, limit the extent to which local
communities' investments in drinking water or wastewater infrastructure can
be deferred or avoided. For example, an ongoing study estimates that for the
16 localities analyzed to date, the standards will cause water consumption
to be reduced enough to save local water utilities from $165.7 million to
$231.2 million by 2020 because planned investments to expand drinking water
treatment or storage capacity can be deferred or avoided.2 Location-specific
estimates for wastewater treatment facilities indicate that reductions in
wastewater flows can also lead to significant savings. For example, one
regional authority estimates savings of $12 million to $14 million for each
million-gallons-per-day reduction in wastewater flows. However, the
estimates for both drinking water and wastewater infrastructure are only as
accurate as the predictions that individual utilities are able to make about
future investment decisions and, for the most part, do not account for the
fact that some use of water-efficient fixtures would continue in the absence
of the national standards. Repealing the national water efficiency standards
could exacerbate the financial pressures facing local communities by forcing
them to build or expand treatment and storage facilities sooner than
planned. However, even if the standards were repealed, state and local
officials told us that imposing moratoria on new residential or commercial
construction would be considered only as a last resort.
The Energy Policy Act of 1992 established water conservation standards for
the manufacture of four types of plumbing fixtures: toilets, kitchen and
lavatory faucets, showerheads, and urinals. With limited exceptions, the
standards apply to all models of the fixtures manufactured after January 1,
1994.3 (See table 1.)
Fixture type Maximum allowable water use
Toilets, including gravity tank-type
toilets,a flushometer tank toilets,b and 1.6 gallons per flush
electromechanical hydraulic toiletsc
2.5 gallons per minute, when
Kitchen and lavatory faucets (or measured at a flowing water
replacement aeratorsd ) pressure of 80 pounds per square
inch
2.5 gallons per minute, when
Showerheads measured at a flowing water
pressure of 80 pounds per square
inch
Urinals 1.0 gallon per flush
aA gravity tank-type toilet is designed to flush by gravity only with water
supplied to the bowl.
bA flushometer tank toilet is designed to flush using a flushometer valve,
which is attached to a pressurized water supply pipe and, when actuated,
opens the line for direct water flow into the bowl at a rate and
predetermined quantity needed to properly operate the toilet.
cAn electromechanical hydraulic toilet is designed to flush using
electronically controlled devices, such as air compressors, pumps, motors,
or macerators in place of or as an aid to gravity in flushing the toilet
bowl.
dAn aerator is an apparatus for controlling water flow (e.g., from faucets).
Under the Department of Energy's regulations, water-efficient plumbing
fixtures must meet the standards for maximum water consumption. For each
model of a regulated plumbing fixture, manufacturers and private labelers
must submit a compliance statement to the Department to certify that the
model complies with the applicable water conservation standard and that all
required testing has been conducted according to the test requirements
prescribed in the regulations. In addition, the Department's regulations
prohibit manufacturers and private labelers from distributing in commerce
any fixture that does not meet the water conservation standard prescribed
under the Energy Policy Act of 1992, and provide for the assessment of a
civil penalty of not more than $110 per violation.
The plumbing industry has also established certain performance or efficiency
standards for water-efficient plumbing fixtures. For example, manufacturers
must demonstrate that low-flow toilets consume no more than 1.6 gallons per
flush and can pass a series of tests directed at the effectiveness of the
toilet's flushing performance and other factors, and each new toilet model
must be tested for compliance by an approved laboratory before it reaches
the marketplace. Testing protocols for demonstrating compliance with these
standards are developed by the American Society of Mechanical Engineers and
approved by the American National Standards Institute.
Most of the water consumed for domestic and commercial purposes is supplied
by public drinking water systems, which account for about 12 percent of the
total fresh water use in the United States, according to a recent report by
the U.S. Geological Survey.4 Water used for agricultural purposes, including
water for irrigation and livestock, accounts for about 41 percent of total
fresh water use, and the water used by thermoelectric power plants is about
39 percent of the total. Growing concerns about the adequacy of public water
supplies to meet increased demands led a number of states and localities to
impose their own requirements for water-efficient plumbing fixtures before
the national standards took effect.
Levels and Wastewater Flows
Substantial evidence shows that the use of water-efficient plumbing fixtures
conserves water. A number of localized studies have measured the impact of
installing water-efficient plumbing fixtures through sophisticated sensors,
before-and-after comparisons of water bills, or other means. Although the
results varied, the studies generally concluded that low-flow fixtures are
effective in saving water. Determining the extent to which the use of
low-flow fixtures is attributable to the national standards is problematic
because some use of low-flow fixtures would likely occur for other reasons.
Two major studies now under way are attempting to estimate the standards'
impact on water consumption and wastewater flows over the long term.
Plumbing Fixtures Conserve Water
Although no major studies estimating the nationwide impact of the national
water efficiency standards have been completed so far, a number of studies
have been conducted to measure the extent to which water-efficient plumbing
fixtures conserve water. The most comprehensive study we found was funded by
the American Water Works Association's Research Foundation, in conjunction
with 22 municipalities and water organizations.5 The purpose of the study
was to gather empirical evidence on variations in water use for plumbing
fixtures and other water-using appliances within single-family homes.6
Sophisticated sensors were placed on residential water meters at about 100
households in each of the 12 participating study sites to obtain detailed
information on actual water use.7 Figure 1 shows, for the 12 study sites,
the distribution of indoor water use by type of fixture. According to the
study, total mean indoor per-capita water use was 69.3 gallons per day, of
which, toilets accounted for about 18.5 gallons per capita per day, or about
27 percent of the total.
Source: Residential End Uses of Water, American Water Works Association
Research Foundation (1999), p. xxv.
Among other things, the detailed water flow data captured by the sensors
allowed researchers to compare water consumption in homes equipped with
low-flow toilets with those using higher-volume models. Significantly, the
study found that the average number of flushes per day in households with
low-flow toilets was 5.04--only slightly higher than the average of 4.92
flushes per day in households with higher-volume toilets.8 Table 2
summarizes the results of the analysis.
Average water use
Household toilet Average Number of Gallons per Gallons per
types gallons per households toilet per capita per
flush day day
Low-flow only < 2.0 101 24.2 9.6
Mix of low-flow and 2.0 −
higher-volume 3.5 311 45.4 17.6
Higher-volume only > 4.0 776 47.9 20.1
All households 1,188 45.2 18.5
Legend
< means less than
> means greater than
Source: Residential End Uses of Water, American Water Works Association
Research Foundation, pp. 131-132.
In addition to the comprehensive study by the American Water Works
Association's Research Foundation, a number of studies have used similarly
sophisticated equipment to measure water flow to individual appliances at a
small number of households. The purpose of these studies was to estimate
whether water-efficient fixtures reduce water consumption in residences and
if so, by how much. Toilets consume the most water in residences, and, as
such, they have been the focus of the greatest attention, but showerheads,
faucets, and clothes washers have also been considered in these studies,
although the latter will not be subject to national standards until 2004.9
The studies all agree that compared with older toilets, ultra-low-flow
toilets save significant amounts of water, easily overwhelming any changes
in user practices (such as the frequency of flushing). Table 3 summarizes
the results of the studies we examined.
Water use in toilets (gal. per
capita per day)
Location Date Number of Before After Amount Percentage
published households retrofit retrofit saved saved
Boulder,
Colo.a May 1996 14 15.9 7.6 8.3 52
East Bay
Municipal
Utility Oct. 1991 25 12.8c 6.7c 5.3c 41c
District,
Calif.
Seattle, July 2000
Wash.b 37 18.8 8.1 10.6 57
(draft)
Tampa, Fla. Feb. 1993 25 13.3 7.2 6.1 46
aIn this study, half of the toilets were replaced with low-flow toilets and
half were not; the reported savings were obtained by averaging the results
for all toilets--higher-volume and low-flow. For the purpose of this table,
we computed the water use and the amount of savings on the basis of the
results for the replaced toilets.
bWe obtained a copy of the draft report on this study. Because the authors
are still finalizing the report, we did not have all of the information that
would be useful in evaluating the results of this study.
cBecause the study did not explicitly report the average water use before
and after retrofit, we estimated these values by multiplying the average
volume per flush by the number of flushes per person. The difference between
these values does not equal the amount of savings reported in the study,
which was measured separately for each toilet before averaging and, thus, is
more accurate.
Sources:
Boulder: Project Report: Measuring Actual Retrofit Savings and Conservation
Effectiveness Using Flow Trace Analysis. Prepared for: City of Boulder,
Colorado, Utilities Division, Office of Water Conservation, by Aquacraft
Water Engineering & Management (May 16, 1996).
East Bay: East Bay Municipal Utility District Water Conservation Study.
Prepared for: East Bay MUD, Oakland, California, A. Aher, et al, Stevens
Institute of Technology, Building Technology Laboratory, T. P. Konen,
Director, Report No. R 219 (Oct. 1991).
Seattle: Draft report prepared for EPA and Seattle Public Utilities, by P.
Mayer and W. DeOreo, Aquacraft, Inc., private communication from P. Mayer
(July 2000).
Tampa: The Impact of Water Conserving Plumbing Fixtures on Residential Water
Use Characteristics: A Case Study in Tampa, Florida. Prepared for: City of
Tampa Water Department, Water Conservation Section, by Stevens Institute of
Technology and Ayres Associates, T. P. Konen and D. L. Anderson, Principal
Investigators (Feb. 1993).
While it is widely believed that the installation of water-efficient
showerheads and sink faucets also results in significant savings, the
studies we reviewed are not in complete agreement on this point. The East
Bay, California, study reported savings of 1.7 gallons per capita per day
with low-flow showerheads--about one-third of the savings resulting from
toilet replacement. The Tampa, Florida, study reported savings of 3.6
gallons per capita per day--(1) more than half of the savings from toilet
replacement and (2) just over one-third of the total water used for showers
before the replacement. On the other hand, the study in Boulder, Colorado,
which also used the most advanced equipment, found that showerhead
replacement had no statistically significant effect on shower water
consumption. The authors of this study called for further research, knowing
that this result was anomalous compared with other, similar studies.
For clothes washers, the largest user of water in households after toilets,
two studies examined the savings associated with using water-efficient
appliances: one in Boulder, Colorado, and one in Seattle, Washington. In
Boulder, only 4 of the 14 homes involved in the study had water-efficient
washers installed for the test period--2 homes used one model of washer, and
2 homes used another model. In the test homes, the study found an average
reduction of 61 percent in water use for clothes-washing--from 17.9 to 7.0
gallons per capita per day. One of the models tested reduced water
consumption for clothes-washing by 39 percent on average, and the other
produced a 76-percent reduction. A variety of clothes washers were tested in
the Seattle study, and the results showed a savings of 5.4 gallons per
capita per day, or a reduction of about 37 percent from the baseline water
use.
Although the studies discussed here all indicate that low-flow toilets and
other water-efficient fixtures save significant amounts of water, evidence
suggests that the savings could be even greater if performance across all
models of the fixtures were more consistent. In the case of toilets,10 the
technology has improved over time, according to water industry
representatives, manufacturers, plumbing contractors, and an official with
the American Society of Mechanical Engineers. They told us that when the
national standards first took effect, existing toilet models were modified
so that they used less water, but until the basic design was changed to
accommodate the lower water flow, some models did not perform effectively.
Today, there is wide agreement that the technology is much better than in
the past; however, some of the officials we interviewed, including plumbing
contractors and water industry representatives, believe that the performance
tests required under the industry standards for low-flow toilets are too
easy to pass and, as a result, some poorly performing models still reach the
market. (See app. I for additional information on the required performance
tests for low-flow toilets and how the requirements have evolved over time.)
Standards Will Continue to Reduce Water Consumption and Wastewater Flows in
the Long Term
Estimating the impact of the national standards is difficult because some
use of low-flow fixtures would likely occur for other reasons--that is, even
in the absence of the standards. Nevertheless, major studies initiated by
the American Water Works Association and EPA are developing long-term
projections of the nationwide impact of the water efficiency standards,
using precise measurements of the water savings per fixture as a starting
point and taking into consideration expected population growth, the average
replacement rate for plumbing fixtures, and other data. Preliminary results
indicate that over the long term, reductions in water consumption and
wastewater flows could be substantial.
Estimating the National Standards' Impact Is Difficult Because Some Use of
Water-Efficient Fixtures Would Likely Occur Even Without the Standards
The studies by both the American Water Works Association and EPA are
attempting to quantify the effect of the national water efficiency standards
for plumbing fixtures. In both cases, the estimate of future savings depends
in part on assumptions about the baseline--that is, the extent to which the
use of low-flow fixtures would occur for reasons other than the national
standards. We identified the following circumstances in which the use of
water-efficient plumbing fixtures had occurred prior to the standards, as
well as factors suggesting that their use is likely to continue whether or
not the national standards are in effect:
� State and local standards that preceded the national standards. Sixteen
states and 6 localities had water efficiency standards for at least two of
the plumbing fixtures regulated under the Energy Policy Act before the
national standards took effect in 1994. As of 1999, about 50 percent of the
nation's population resided in these locations. All of the states and
localities had standards for low-flow toilets that, with one exception, were
consistent with the current national standard. State and local standards for
showerheads, faucets, and urinals varied from the national standard more
frequently. Officials from all 16 states and 2 of the 6 localities with
preexisting standards believe that their standards would automatically
revive if the national standards were repealed.11 (See app. II for detailed
information on state and local water efficiency standards.)
� Incentives, such as rebates, to encourage the installation of low-flow
fixtures. We identified at least 36 localities in 12 states that have
sponsored rebate or free replacement programs, mostly in states and/or
localities whose own standards for water-efficient plumbing fixtures
preceded the national standards. Under these programs, the community offers
some type of financial incentive to encourage people to replace their
toilets or other plumbing fixtures with more efficient models sooner than
they would have otherwise. We selected six localities--Austin, Texas; Los
Angeles, California; New York, New York; Phoenix, Arizona, and Tampa and
Hillsborough County, Florida--to collect information about their rebate
programs, all of which began before or during 1994.12 We found that over 2.3
million low-flow toilets have been installed under the six rebate programs,
thereby saving more than 100 million gallons of water per day. With the
exception of New York City, all of these communities continue to offer
rebates, and, according to a city official, New York is considering a second
rebate program. (See app. III for a summary of the accelerated toilet
replacement programs in the six localities.)
� Manufacturers' desire for consistency. According to an official with the
Plumbing Manufacturers' Institute and industry representatives,
manufacturers would be reluctant to return to making higher-volume plumbing
fixtures because of (1) the high cost of retooling and (2) the ease of
complying with a single national standard rather than a hodgepodge of
requirements across the country.
� Local ordinances requiring low-flow fixtures. For example, we found a few
instances of local "retrofit on resale" ordinances in California, two of
which were adopted before the national standards took effect.13 Typically,
these ordinances require that for any residential or commercial property
offered for sale, the owner must certify that the property has been totally
retrofitted with low-flow toilets and other efficient plumbing fixtures.
According to an official with the California Urban Water Conservation
Council, this requirement is currently being considered for statewide
application because of the state's severe water shortage.
American Water Works Association Is Studying Impact on Water Consumption
In January 2000, the American Water Works Association commissioned a study
to estimate the long-term impact of the national water efficiency standards
on water consumption from public water systems. To obtain a national picture
of the standards' impact, surveys were sent to over 3,700 drinking water
utilities across the United States; as of June 21, 2000, over 650 utilities
had responded. The Association's contractor is analyzing the responses and
entering this information into a model developed to estimate future water
demand with and without the national standards. The estimated completion
date for the study is September 30, 2000. As shown in figure 2, preliminary
projections for 16 utilities, which currently serve nearly 11 million
people, indicate that given expected population growth, water consumption
will be reduced by 3.3 to 9.1 percent by 2020 as a result of the national
standards. (See app. IV for a table of the projected water savings by 2010
and 2020, by location.)
Legends
WSSC=Washington Suburban Sanitary Commission
Source: Analysis conducted by Maddaus Water Management for the American
Water Works Association.
The American Water Works Association's study attempts to estimate the
savings associated with water-efficient plumbing fixtures by using
location-specific data on projected population growth, projected water
demand, and the age of the existing housing stock. With the information on
existing housing stock, the study makes assumptions about the percentage of
households that already have low-flow fixtures (e.g., homes constructed
after January 1, 1994, should be completely fitted with efficient fixtures)
and the rate at which older, higher-volume fixtures will be replaced with
low-flow models. The accuracy of these assumptions could have a significant
effect on the validity of the projected reduction in water consumption. For
example, the study uses a relatively conservative assumption regarding the
replacement rate for toilets--3 percent per year compared with the plumbing
industry's estimates of 4 to 5 percent per year. Using a higher replacement
rate would increase the savings attributable to water-efficient fixtures by
2020.
As noted above, one difficulty in estimating the impact of the standards is
determining a baseline against which projected water savings are derived,
taking into account the savings that might occur without the national
standards. In estimating water consumption without the national standards,
the model used by the Association's contractor assumes that about 30 percent
of the toilets installed in the future would be low-flow models (1.6 gal.
per flush) and that the remaining 70 percent would use 4.6 gallons per
flush. If the factors noted above resulted in a greater-than-30-percent
proportion of low-flow fixtures, even in the absence of the national
standards, then the actual savings attributable to the standards would be
less than that estimated by the Association.
EPA Is Studying Impact on Wastewater Flows
While the American Water Works Association focused on water consumption from
drinking water facilities, EPA is sponsoring a major study to estimate the
long-term impact of the national water efficiency standards on the level of
wastewater flows into treatment plants. The model used to predict the
standards' impact on wastewater flows incorporates information from a
variety of sources, including plumbing manufacturers, U.S. Census
Statistical Abstracts, water utility case studies, Consumer Reports, the
American Water Works Association Research Foundation, and other sources.
Preliminary results from this study indicate that wastewater flows to
publicly owned treatment works will be reduced by about 13 percent by
2016.14
As in the American Water Works Association study, the reasonableness of key
assumptions in EPA's study could have a significant effect on the validity
of results. Most significantly, EPA's study attributes all savings from
water-efficient plumbing fixtures to the national standards and does not
attempt to estimate the reduction in wastewater flows that would have
occurred in the absence of the standards. Consequently, the estimated
savings are likely overstated.
Furthermore, according to the agency's contractor, few historical data are
available to validate the model's projections, but the model uses relatively
conservative assumptions that are periodically cross-referenced against data
from industry and other sources. At the time of our review, the extent of
the risk analysis, which is done to determine how sensitive the long-term
projections are to plausible variations in the values assigned to key
variables, was limited to replacement rates for the plumbing fixtures. For
example, the contractor computed a low estimate of long-term water savings
using a 2-percent replacement rate for residential toilets and a high
estimate using a 7-percent replacement rate.
Timing and Cost of Infrastructure Investments
By reducing water consumption and wastewater flows, the use of
water-efficient plumbing fixtures may allow local communities to save money
by deferring or even avoiding investments in water or wastewater
infrastructure. Case studies of specific localities suggest that the
nationwide savings in infrastructure investments could potentially be in the
billions of dollars. Repealing the national standards could force local
communities to expand the capacity of their drinking water or wastewater
treatment facilities sooner than they would otherwise, presenting problems
for those already hard-pressed to handle the cost of upgrading or replacing
existing facilities. Determining the precise impact of repeal is problematic
because, as noted above, the installation of water-efficient plumbing
fixtures--and the associated water savings--will continue to some extent in
the absence of national standards. Although many communities are concerned
about the scarcity of water resources, they would probably pursue other
alternatives before considering moratoria on new construction, according to
the states and localities we contacted.
Avoiding Some Infrastructure Investments
Preliminary results from the ongoing study sponsored by the American Water
Works Association indicate that the ability to avoid or defer planned
investments in drinking water infrastructure as a result of reduced water
consumption could save local communities millions of dollars. For the 16
utilities included in the study so far, the total savings associated with
deferred or avoided infrastructure are estimated to range from $165.7
million to $231.2 million by 2020, depending on whether the projected
savings are discounted at 3 or 7 percent, respectively. The projected
savings amount to approximately 3.6 percent of the total project costs
without the national water efficiency standards in place.15
The savings estimated for individual localities vary widely on the basis of
their size, the projected water demand, and the timing and cost of planned
investments in expanded treatment or storage capacity over the next 20
years. (See app. V for a table that shows projected infrastructure
investments with and without the national water efficiency standards and the
present value of the estimated savings, by location.)
While the estimated savings associated with a community's ability to defer
or avoid investments appear to be substantial, the American Water Works
Association's contractor acknowledged that the estimates are only as
accurate as the predictions that individual utilities are able to make about
future investment decisions. He told us that some utilities simply have not
prepared detailed demand forecasts or projected their long-term
infrastructure needs. He believes that other utilities may have provided
information on their total infrastructure needs--including the investments
needed to comply with Safe Drinking Water Act requirements or to replace or
upgrade existing facilities--and did not isolate the investments related to
expanded capacity. In addition, to the extent that the analysis does not
account for the fact that some use of water-efficient fixtures would
continue in the absence of the national standards, the estimated savings are
likely overstated.
As part of its ongoing study of the impact of the national water efficiency
standards on wastewater flows, EPA intended to develop a national estimate
of how reduced wastewater flows might affect planned investments in
wastewater treatment infrastructure, using its database on projected
wastewater treatment needs. However, the database does not adequately
distinguish between planned investments in expanded capacity and those for
replacing or upgrading existing capacity. In addition, the database does not
provide enough detail on the cost of individual treatment processes or the
timing of planned infrastructure investments. Finally, the wide variation in
the size and configuration of local wastewater treatment facilities makes
developing a national estimate problematic.
As an alternative to developing a national estimate, EPA's contractor is
using a case study approach and collecting information on the impacts of
reduced wastewater flows on planned infrastructure investments in specific
localities. Several cases have been developed to date, but it is difficult
to isolate the impacts of using water-efficient plumbing fixtures from other
conservation measures adopted by the localities, as shown in the following
examples:
� The average dry weather flows at New York City's 14 wastewater treatment
plants have dropped about 17 percent from fiscal year 1994 to fiscal 1999,
and plans to expand the capacity of at least 4 of the plants have been
halted. The cost of expanding one plant alone was estimated to be as high as
$1.2 billion. However, aggressive conservation efforts--including an
accelerated toilet replacement program, leak detection and repair,
large-user audits, and other measures--made this and other investments
unnecessary.
� After a 1995 study projected that existing wastewater treatment capacity
would be exceeded by 2001, a regional wastewater treatment authority in
Washington State used several approaches to reduce wastewater flows,
including the reduction of infiltration and inflow,16 rebates for low-flow
toilets and clothes washers, toilet leak reduction, public education, and
submetering.17 The authority estimates that it will save about $12 million
to $14 million for every 1 million gallons per day of capacity expansion it
can avoid.
Local Communities
According to EPA's infrastructure needs surveys for drinking water and
wastewater treatment, local communities are faced with potentially huge
investments to expand or upgrade their facilities.18 In 1997, EPA reported
to the Congress that the total projected needs for all categories of
activities eligible for funding under the clean water state revolving fund
were $139.5 billion over the next 20 years, including $44.0 billion just for
secondary and advanced wastewater treatment.19 Similarly, EPA reported in
1997 that the nation's 55,000 community drinking water systems must invest a
minimum of $138.4 billion over the next 20 years to install, upgrade, or
replace infrastructure.20 About $48 billion of the estimated needs is for
drinking water treatment and storage facilities.
More recently, the Water Infrastructure Network, an affiliation of various
utility, government, and public works associations, sponsored its own study
of water and wastewater infrastructure needs.21 The final report concluded
that the total needs--including capital investments, the cost of financing,
and annual facility operation and maintenance costs--will approach $2
trillion over the next 20 years. The report also states that in terms of
capital investments, the gap between what local communities are currently
spending and the amount needed to build, replace, and rehabilitate new and
existing water and wastewater systems is an estimated $23 billion per year,
of which $11 billion is needed for drinking water systems and $12 billion is
needed for wastewater systems.
To the extent that using water-efficient plumbing fixtures allows
communities to defer or even avoid investments in drinking water and
wastewater treatment infrastructure, repealing the national standards could
force local communities to make these investments sooner than anticipated.
It is difficult to predict the precise impact that such a repeal would have
on local communities because some conservation efforts will continue,
regardless.
During our interviews with officials from states and localities whose water
efficiency standards preceded the national requirements, we asked about
their ability to finance the additional infrastructure that might be needed
if the national standards were repealed. Several of these officials told us
that obtaining the funds to finance the costs for additional drinking water
and wastewater treatment infrastructure is difficult, primarily because the
burden usually falls on individual consumers. While the states have
revolving loan funds for financing drinking water and wastewater treatment
infrastructure, this money goes only so far. For example, Massachusetts
received about $660 million in loan applications from local communities last
year to finance improvements in drinking water facilities, of which, the
state was able to fund only $127 million--about 19 percent of the total
requested.
If financing is not available from the revolving loan funds or other federal
sources,22 local communities must rely on other methods for funding
infrastructure, including issuing bonds and/or increasing taxes. According
to several of the officials we interviewed, obtaining approval for these
funding methods is difficult because of public resistance to higher fees or
taxes.
Alternatives Before Imposing Constraints on New Construction
We conducted semistructured interviews with officials from the 16 states and
4 of the 6 localities that had adopted their own water efficiency standards
about the likelihood that local communities would impose building moratoria
or other constraints on new construction if the national standards were
repealed. According to several of the officials we contacted, building
moratoria are rarely imposed. Only 7 of the 16 states indicated that
moratoria have been used as a result of water shortages, usually by only 1
or 2 communities within the state.
Officials from the four localities we contacted indicated that they would be
extremely reluctant to impose moratoria on new construction and that such
measures would be used only as a last resort. For example, local water
officials in Tampa and Hillsborough County, Florida, told us that they have
never imposed a moratorium on new construction because doing so would be
devastating to the region's economic growth. An official from the Southwest
Florida Water Management District, the regulatory agency responsible for
managing the water resources in a 16-county area, including Tampa and
Hillsborough County, said that constraints on new construction are
politically infeasible.
State officials told us that localities are using or considering other
methods to deal with current or anticipated water shortages--methods that
increase water conservation or develop new sources of supply. Officials from
Georgia, Oregon, and Utah said that local communities within their state
have modified or would consider modifying their water rates to encourage
water conservation. In these instances, instead of offering volume
discounts, the local water system changes its rate structure so that the
rates increase as water use increases. Officials from Dade and Hillsborough
Counties in Florida; Tampa, Florida; and Denver, Colorado, told us that they
have adopted this inverted rate structure.
Some localities are taking steps to supplement their water supply. One
alternative is the use of "reclaimed water," which is wastewater that is
treated and reused as a nonpotable water source. Hillsborough County is
already using reclaimed water for lawn watering, and Tampa is planning to
implement a reclaimed water project in 2001. Desalination of seawater is
another option. Tampa Bay Water, which supplies water to public utilities in
Hillsborough County and the city of Tampa as well as other abutting
counties, is building a desalination plant, which will provide 25 million
gallons of water per day by the end of 2002.
We provided EPA with a draft of this report for review and comment.
Officials within EPA's Office of Water, including the Acting Chief of the
Protection Branch from the Office of Ground Water and Drinking Water and the
Director of the Office of Wastewater Management, generally agreed with the
facts presented in the report. However, the Office of Wastewater Management
provided a revised estimate of total wastewater flows to publicly owned
treatment plants in 2016 and a new determination of the projected reduction
in wastewater flows that would be attributable to the population served by
such facilities. We incorporated this change into our report. In addition,
EPA officials suggested a number of technical corrections and
clarifications, which we incorporated as appropriate.
The scope and methodology we used for our work are discussed in appendix VI.
We performed our work from January through August 2000 in accordance with
generally accepted government auditing standards.
As arranged with your offices, unless you announce its contents earlier, we
plan no further distribution of this report until 30 days after the date of
this letter. At that time, we will make copies available to interested
congressional committees; the Honorable Carol M. Browner, Administrator,
Environmental Protection Agency; and the Honorable Jacob J. Lew, Director,
Office of Management and Budget. We will make copies available to others on
request.
If you have any questions regarding this report, please contact me at (202)
512-6111. Key contributors to this assignment were Willie Bailey, Charles
Bausell, Ellen Crocker, Richard Frankel, Ingrid Jaeger, and Robert Sayers.
Peter F. Guerrero
Director, Environmental
Protection Issue
Evolution of Required Performance Tests for Low-Flow Toilets
Despite technological improvements, performance among low-flow toilets can
still vary widely in terms of the amount of water used and flushing
capability, according to a number of sources. Some of the officials we
interviewed, including plumbing contractors and water industry
representatives, believe that the performance tests required under the
industry standards for low-flow toilets are too easy to pass and, as a
result, some poorly performing models reach the market. One concern about
current testing procedures is that they do not include an effective
performance test that addresses the extent to which a toilet is subject to
clogging--a problem that can contribute to higher-than-expected water use.
The customer satisfaction surveys we reviewed also indicated that in key
aspects of performance, such as clogging and the need for double flushing,
the effectiveness of low-flow toilets can vary significantly, depending on
the model.23 Officials from the Plumbing Manufacturers Institute agree that
industry standards are an important factor in ensuring that the performance
of low-flow toilets is consistently good across the industry. However, they
also point to improper installation as a major reason why low-flow toilets
may exceed 1.6 gallons per flush or otherwise perform poorly in the field.
Over the past 10 years, manufacturers have been working to strengthen the
testing requirements for low-flow toilets, but industry representatives
acknowledge that it has taken a long time to reach agreement on new tests
that would address the toilets' flushing capability. When the industry
standards for low-flow toilets were updated in 1990, an existing test for
clogging was eliminated, according to an official with the American Society
of Mechanical Engineers. Although such a test was considered and rejected
when the standards were updated in 1995, the standards are currently
undergoing another revision, and the Society's project team has reached
agreement with manufacturers to add a test for clogging.24 The proposed
revision must be approved by the Society to become an American National
Standard; a vote is expected in August 2000. Table 4 shows how the testing
requirements have changed over the past 10 years.
Test name Test description 1990 1995 Pending revision,
edition edition 2000a
To determine average
Water water consumption:
consumption per average consumption New Same Same
flush shall not exceed 1.6
gallons.
To determine maximum
water consumption
after adjusting trim
Maximum water components for
consumption per maximum water use: N/A N/A New
flush average water
consumption shall
not exceed 2.4
gallons.
To determine solids
removal: 100
polypropylene balls
Ball test are placed in toilet Same Same Deleted; combined
bowl; 75 must be with granule test
removed in initial
flush.
To determine solids
removal: 2,500
polyethylene Adds 100 nylon
balls; not more
Granule test disc-shaped pellets Same Same than 3 are allowed
are placed in toilet
bowl; not more than to remain after
125 may remain after initial flush
initial flush.
To determine rim
washing: a water
soluble ink is
marked on a bowl's A second line is
surface; after added 2 inches
Ink line test initial flush, no Same Same below rim jets;
line segment can this line is
exceed inch, and completely washed
aggregate of all away
segments may not
exceed 2 inches.
To determine water
exchange: a dye is
Dye test added to bowl; 100 Same Same Deleted
percent dilution
must occur after
initial flush.
To determine if trap
seal works properly:
Trap seal test fixture must return Same Same Same
to full trap seal
after each flush.
To determine solids
removal: 12 sponges
Mixed media and 10 paper balls
test are used; not more N/A N/A New
than 4 sponges or
balls may remain
after initial flush.
To determine length
of transport of
Drain line solid wastes:
carry test fixture must carry New Same Same
waste a minimum of
40 feet in the drain
line.
To determine leakage
of gravity tank-type
toilets: tank fill
Overflow test valve is opened to N/A N/A New
maximum flow for 5
minutes; fixture
shall not leak.
To determine wetting
of person sitting on
seat during flush: a
Water rise test vertically
positioned rod is
New Same Deleted
placed 3 inches
under the bowl rim;
during flush, water
should not touch
rod.
To determine soiling
of rim top and seat:
Rim top and a plate is placed
seat fouling over toilet bowl; no N/A New Deleted
test water shall splash
on plate during
flushing.
Legend
N/A = not applicable
aThe pending changes to the performance tests for low-flow toilets are being
proposed by the American Society of Mechanical Engineers (ASME). The changes
will be up for approval as a national standard at the August 2000 meeting of
the Society.
Sources: Hydraulic Performance Requirements for Water Closets and Urinals,
The American Society of Mechanical Engineers, An American National Standard.
ASME A112.19.6. (1990, 1995) and Vitreous China Plumbing Fixtures and
Hydraulic Requirements for Water Closets and Urinals, The American Society
of Mechanical Engineers, ASME A112.19.2 −2000 (May 2000 draft).
Preexisting State and Local Standards for Water-Efficient Plumbing Fixtures
and Their Status If National Standards Were Repealed
Sixteen states and 6 localities had water efficiency standards for at least
two of the plumbing fixtures regulated under the Energy Policy Act before
the national standards took effect in 1994. Table 5 compares the standards
adopted by each jurisdiction with the national standards.
Water-efficiency standard
Kitchen Lavatory
Ultra-low-flow Low-flow faucets faucets Urinals
State/localityEffective toilets (gal. showerhead (gal. (gal. (gal.
datea (gal. per per
per flush) per per
minute) flush)
min.) min.)
National Jan. 1,
standard 1994 1.6 2.50 2.5 2.5 1.0
States
Arizona Jan. 1, 1.6 2.50 2.5 2.0 None
1993
California Jan. 1, 1.6 2.50 2.5 None 1.0
1992
Connecticutb Jan. 1, 1.6 2.50 2.5 2.5 1.0
1990
Delaware Apr. 1, 1.6 2.50 2.5 2.0 1.0
1992
Georgia Apr. 1, 1.6 2.50 2.5 2.0 1.0
1992
Maryland Apr. 1, 1.6 2.50 2.5 2.0 1.0
1992
Massachusetts Mar. 2, 1.6 3.00 None None 1.0
1989
Nevada Mar. 1, 1.6 2.50 2.5 2.5 1.0
1993
New Jerseyb July 1, 1.6 3.00 3.0 3.0 1.5
1991
New Yorkb Jan. 1, 1.6 3.00 None 2.0 1.0
1992
North Jan. 1,
Carolinab 1993 1.6 3.00 3.0 3.0 1.5
Oregon July 1, 1.6 2.50 2.5 2.5 1.0
1993
Rhode Islandb Mar. 1, 1.6 2.50 2.0 2.0 1.0
1991
Texas Jan. 1, 1.6 2.75 2.2 2.2 1.0
1992
Utah July 1, 1.6 2.50 None None None
1992
Washington July 1, 1.6 2.50 2.5 2.5 1.0
1993
Localities
Dade County, Jan. 1,
Fla. 1992 1.6 2.50 2.5 2.0 1.0
Denver, Colo. Mar. 1, 1.6 2.50 2.2 2.2 1.0
1992
District of Jan. 1,
Columbia 1992 1.6 2.50 2.5 2.0 1.0
Hillsborough Mar. 26,
County, Fla. 1992 1.6 2.50 2.2 2.2 1.0
Palm Beach, Apr. 1,
Fla.b 1991 1.6 3.00 None None 1.5
Tampa, Fla.b June 1, 2.0 2.50 2.0 2.0 1.0
1990
aThe effective date for the national standards applies to all models of the
fixtures, with limited exceptions, manufactured after January 1, 1994. For
the state and local standards, the effective date applies to the standards
for ultra-low-flow toilets. Four states had different effective dates on
standards for other plumbing fixtures. For example, Massachusetts' effective
date for toilets was March 2, 1989, and August 9, 1996, for showerheads.
bAfter the passage of the Energy Policy Act of 1992, state laws and/or local
standards were revised to comply with national standards.
Sources: For each state, data were obtained from telephone interviews of
state or local water officials. For all localities except the District of
Columbia, data were obtained from local water officials. Data for the
District of Columbia were obtained from Ranton, Judith L., Water Efficient
Plumbing Fixture Legislation, A Poll of States With Legislation Adopted,
City of Portland, Oreg., Bureau of Water Works (May 1992).
When the Energy Policy Act of 1992 established the national standards, it
also preempted state and local authorities from setting differing standards.
We conducted semistructured interviews with officials from the 16 states and
4 of the 6 localities with preexisting standards to obtain their views on
the likely status of their standards if the national standards were
repealed. All of the state officials we contacted believe that their
standards would automatically revive. At the local level, officials from two
localities told us that their local plumbing codes had been modified to
incorporate the national standards. If the national standards were repealed,
local officials told us that they would have to take some affirmative action
to reinstate water efficiency standards at the local level. The other two
localities never amended their local plumbing codes and thus, officials
believe that their standards would revive upon repeal of the national
standards.
Both state and local officials told us that if the national standards were
repealed, enforcement of their standards would become a major problem,
particularly for localities. According to several of these officials,
although the national standards regulate the manufacture of water-efficient
plumbing fixtures and, in effect, make higher-volume products unavailable to
consumers, state and local standards typically apply only to the
installation of efficient fixtures. Thus, reinstating state and local
standards would not affect the manufacture of higher-volume fixtures or
prevent the sale of such products in neighboring jurisdictions.
Summary of Accelerated Toilet Replacement Programs in Six Localities
Number of Total
Period toilets Estimated estimated
water Cost of
Location covered by distributed toilet
program free or water
statistics through rebate savings savings program
program per
toilet
(gal. per
(gal. per day)
day)
Austin, Tex. 1992-Sept. 48,222 29.3 1,400,000 $2.0
1999 million
Los Angeles, 1990-Feb. 107
Calif. 2000 905,923 31.7 28,700,000 milliona
New York, 1994-Apr. 290
N.Y. 1996 1,300,000 53.8b 70,000,000 million
Phoenix, 1994-Mar.
Ariz. 2000 1,226 25.6 78,464 96,000
Tampa, Fla. 1993-Sept. 15,263 29.1 440,400 1.7
1999 millionc
Hillsborough 1994-Sept. 8.8
County, Fla. 1999 60,305 23.4 1,400,000 million
Total 2,330,939 102,018,864
aCosts include other conservation efforts, such as showerhead and
clothes-washer rebates, but the primary costs are for toilets.
bA New York City official attributed the higher savings per toilet in that
city to the replacement of older, higher-volume toilets (5- to
7-gallons-per-flush toilets installed prior to 1950) in high-density
neighborhoods.
cIn May, we reported that the cost of the Tampa program was $1.2 million
dollars. Since then, a program official provided us with revised cost data.
(See GAO/RCED-00-161R, May 1, 2000.)
Projected Reduction in Water Consumption by 2010 and 2020, by Location
(Continued From Previous Page)
Projected water use and savings in millions of gallons per day
Average daily water use Projected daily
water savings
Without
With water
Location Population Year water efficiency Percentage
efficiency
standards standards Amount
Austin, Tex.,
City of
Austin Water 650,000 2010 167.5 160.8 6.7 4.0
& Wastewater
Utility
2020 230.9 215.2 15.7 6.8
Boston,
Mass., Boston
Water & Sewer 650,000 2010 84.2 81.0 3.2 3.8
Commission
2020 85.1 79.4 5.7 6.7
Cary N.C.,
Town of Cary 84,779 2010 16.1 15.1 1.0 6.2
2020 23.1 21.0 2.1 9.1
Clarksburg,
W. Va.,
Clarksburg 19,000 2010 2.9 2.8 0.1 3.4
Water Board
2020 3.6 3.4 0.2 5.5
Fort Worth,
Tex., Fort
Worth Water 753,116 2010 170.0 166.6 3.4 2.0
Department
2020 178.8 172.9 5.9 3.3
Laurel, Md.,
Washington
Suburban 1,700,000 2010 206.3 199.7 6.6 3.2
Sanitary
Commission
2020 224.1 212.0 12.1 5.4
Los Angeles,
Calif., Los
Angeles 3,800,000 2010 560.6 542.1 18.5 3.3
Department of
Water & Power
2020 560.3 527.8 32.5 5.8
Michigan
City, Ind.,
Michigan City 41,000 2010 12.1 11.7 0.4 3.3
Department of
Water
2020 12.7 12.0 0.7 5.5
Oceanside,
Calif., City
of Oceanside 157,869 2010 37.5 36.6 0.9 2.4
Water
2020 46.2 44.4 1.8 3.9
Phoenix,
Ariz.,
Phoenix Water 1,252,425 2010 341.4 331.5 9.9 2.9
Services
2020 393.6 375.1 18.5 4.7
Pinellas
County, Fla.,
Pinellas 643,191 2010 84.4 80.6 3.8 4.5
County
Utilities
2020 89.9 82.8 7.1 7.9
Rockford,
Ill., City of
Rockford 150,000 2010 46.7 44.6 2.1 4.5
Water
Division
2020 62.5 58.5 4.0 6.4
Syracuse,
N.Y., City of
Syracuse 235,000 2010 40.7 39.6 1.1 2.7
Department of
Water
2020 38.8 36.9 1.9 4.9
Tacoma,
Wash., Tacoma 306,000 2010 80.8 78.7 2.1 2.6
Water
2020 92.1 88.6 3.5 3.8
Tampa, Fla.,
City of Tampa
Water 450,000 2010 77.4 75.0 2.4 3.1
Department
2020 81.5 77.1 4.4 5.4
Wausau, Wis.,
Wausau Water 45,000 2010 6.3 6.1 0.2 3.2
Works
2020 5.4 5.1 0.3 5.6
Total 10,937,380 2010 1,934.9 1,872.5 62.4 3.2
2020 2,128.5 2,012.1 116.4 5.5
Note: Population data are as of 1999.
Source: Analysis conducted by Maddaus Water Management for the American
Water Works Association. Using data provided by Maddaus Water Management, we
calculated the average daily water use with and without the water efficiency
standards.
Projected Investments in Drinking Water Infrastructure by the Year 2020, by
Location
Dollars in
millions
Investment projected through 2020, discounted at 3
percent
Without water With water
Location efficiency efficiency Amount of Percent
standards standards savings savings
Austin, Tex., City
of Austin Water & $363.5 $347.8 $15.7 4.3
Wastewater Utility
Boston, Mass.,
Boston Water & 820.7 788.6 32.1 3.9
Sewer Commission
Cary N.C., Town of
Cary 108.9 103.0 5.9 5.4
Clarksburg, W.
Va., Clarksburg 8.5 8.3 0.2 2.4
Water Board
Fort Worth, Tex.,
Fort Worth Water 1,008.7 986.4 22.3 2.2
Department
Laurel, Md;
Washington
Suburban Sanitary 360.3 339.3 21.0 5.8
Commission
Los Angeles,
Calif., Los
Angeles Department 1,722.8 1,663.6 59.2 3.4
of Water & Power
Michigan City,
Ind., Michigan
City Department of 12.7 12.4 0.3 2.4
Water
Oceanside, Calif.,
City of Oceanside 189.3 184.2 5.1 2.7
Water
Phoenix, Ariz.,
Phoenix Water 441.4 428.1 13.3 3.0
Services
Pinellas County,
Fla., Pinellas 491.1 465.9 25.2 5.1
County Utilities
Rockford, Ill.,
City of Rockford 72.0 68.8 3.2 4.4
Water Division
Syracuse, N.Y.,
City of Syracuse
Department of 231.2 224.8 6.4 2.8
Water
Tacoma, Wash.,
Tacoma Water 302.3 300.3 2.0 0.7
Tampa, Fla., City
of Tampa Water 209.5 190.8 18.7 8.9
Department
Wausau, Wis.,
Wausau Water Works 8.1 7.7 0.4 4.9
Total $6,351.0 $6,120.0 $231.0a 3.6
aUsing a 7-percent discount rate, the savings would be $165.7 million.
Source: Analysis conducted by Maddaus Water Management for the American
Water Works Association.
Scope and Methodology
In conducting our review, we collected information from a wide variety of
sources, including the Environmental Protection Agency's (EPA) Office of
Ground Water and Drinking Water and Office of Wastewater Management, the
Department of Energy's Office of Energy Efficiency and Renewable Energy, the
American Society of Mechanical Engineers, the American National Standards
Institute, the American Water Works Association, the Association of
Metropolitan Sewerage Agencies, the California Urban Water Conservation
Council, plumbing manufacturers and contractors, and selected states and
localities. We contacted 16 states and 5 of the 6 localities that adopted
standards for water-efficient plumbing fixtures before the national
standards took effect,25 to wit: Arizona; California; Connecticut; Delaware;
Georgia; Maryland; Massachusetts; Nevada; New Jersey; New York; North
Carolina; Oregon; Rhode Island; Texas; Utah; Washington; Dade County,
Florida; Denver, Colorado; Hillsborough County, Florida; Palm Beach,
Florida; and Tampa, Florida. In addition, we visited six localities (Austin,
Tex.; Los Angeles, Calif.; New York, N.Y.; Phoenix, Ariz.; Tampa, Fla.; and
Hillsborough County, Fla.) to collect more detailed information on
accelerated toilet replacement programs. The criteria used to select these
locations included (1) their use of water efficiency standards, which
preceded the national standards; (2) their use of rebate and/or retrofit
programs to accelerate the installation of low-flow toilets and other
water-efficient fixtures; and (3) an assessment of the programs' impact on
water consumption.
We also obtained and analyzed relevant documents and reports, including the
applicable regulations; performance standards for low-flow toilets; and a
variety of studies on the impact of water-efficient plumbing fixtures. For a
complete list of the studies we reviewed, see the Bibliography.
To obtain information on the estimated impact of the national water
efficiency standards on water consumption levels and wastewater flows, we
reviewed studies that examined the use and impact of water-efficient
plumbing fixtures, including (1) studies that made precise measurements of
water use in a limited number of households, (2) studies that estimated
impacts for an entire locality, and (3) two major studies of the impacts on
water consumption and wastewater flows being sponsored by the American Water
Works Association and EPA, respectively. To the extent possible, we reviewed
the reasonableness of the methodology and assumptions used in the studies.
We also collected information on how well the low-flow fixtures work and how
they are used in practice by reviewing customer satisfaction surveys
administered to participants in accelerated replacement programs and
interviewing plumbing manufacturers and contractors and representatives of
the American Society of Mechanical Engineers and the American National
Standards Institute. To obtain information on the extent to which
water-efficient fixtures might be used in the absence of the national
standards, we conducted semistructured interviews with and collected
documentation from the 16 states and 4 of the 6 localities that adopted
their own standards before the national ones took effect. In addition, we
collected data on accelerated toilet replacement programs and interviewed
plumbing contractors involved in performance-based contracting.
For information on the potential impact of repealing the national standards,
we reviewed studies that examined the timing and cost of local
infrastructure investments with and without the standards in place. We
relied primarily on data and case studies developed for ongoing studies
being sponsored by the American Water Works Association and EPA. To the
extent feasible, we reviewed the reasonableness of the methodology and
assumptions used in the studies we examined. In looking at local
communities' ability to finance additional investments in infrastructure, we
extracted information from EPA's needs surveys for drinking water and
wastewater treatment infrastructure and a more recent needs estimate by the
Water Infrastructure Network--a coalition of various utility, government,
and public works associations. We also addressed this issue--and the
likelihood of constraints on new construction if the national standards were
repealed--during our interviews with officials from states and localities
with preexisting standards for water-efficient plumbing fixtures.
Bibliography
The Conserving Effect of Ultra Low-flush Toilet Rebate Programs. A&N
Technical Services, Inc. A Report Submitted to the Metropolitan Water
District of Southern California. June 1992.
Ultra Low-Flush Toilets in Commercial Installations Prepared for California
Urban Water Agencies and California Urban Water Conservation Council. - - -
- -. California Urban Water Agencies and California Urban Water Conservation
Council. Feb. 1994.
Ultra Low-Flush Toilet Programs, Evaluation of Program Outcomes and Water
Savings. - - - - -. A Report Submitted to the Metropolitan Water District of
Southern California. July 1995.
Technical Issues and Recommendations on the Implementation of the U.S.
Energy Policy Act. Amy Vickers & Associates, Inc. Prepared for American
Water Works Association, Washington, D.C.: Oct. 25, 1995.
Regional Water Supply Demand Management Plan. - - - - -. West Coast Regional
Water Supply Authority. Clearwater, Fla.: June 1997.
Seattle Public Utilities and U.S. Environmental Protection Agency Home Water
Conservation Study Preliminary Results. Aquacraft, Inc., as of July 2000.
Project Report: Measuring Actual Retrofit Savings and Conservation
Effectiveness Using Flow Trace Analysis. Aquacraft Water Engineering &
Management. Boulder, Colo.: May 16, 1996.
Residential End Uses of Water. American Water Works Association Research
Foundation. Dec. 1999.
Water Conservation: Survey of Programs and Potential Benefits to County
Sanitation Districts of Orange County. Camp Dresser & McKee. Orange County,
Calif.: June 1997.
City of Austin, Texas, Environmental and Conservation Services Department.
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(160528)
Table 1: National Water Efficiency Standards 6
Table 2: Water Use by Type of Toilet 10
Table 3: Reported Savings Attributable to Low-Flow Toilets
in Studies Using Precise Measurements 11
Table 4: Evolution of Industry Testing Requirements for Low-Flow
Toilets 27
Table 5: State and Local Standards for Water-Efficient Plumbing
Fixtures 29
Figure 1: Mean Daily Residential Water Use at 12 Study Sites 9
Figure 2: Percentage of Water Savings by Location 17
1. See Residential End Uses of Water, American Water Works Association
Research Foundation (1999).
2. The dollar amounts presented here represent the present value of the net
savings discounted at 7 and 3 percent, respectively.
3. For example, the maximum allowable water use for certain gravity
tank-type toilets labeled as "Commercial Use Only" manufactured after
January 1, 1994, and before January 1, 1997, is 3.5 gallons per flush.
Similarly, flushometer valve toilets were not required to meet the
1.6-gallons-per-flush standard until January 1, 1997. In the case of
"blowout toilets," which use pressurized jets of water to flush the bowl's
contents, the maximum allowable water use is 3.5 gallons per flush.
4. See Estimated Use of Water in the United States in 1995, U.S. Geological
Survey Circular 1200 (1998).
5. See Residential End Uses of Water, American Water Works Association
Research Foundation (1999). The American Water Works Association is a
professional organization representing individuals from the water supply
industry and the drinking water community at large.
6. The study involved 12,000 randomly selected customer accounts, or about
1,000 in each of 12 study sites, and included households with low-flow
fixtures, those with less efficient fixtures, and those with a mix of
low-flow and higher-volume fixtures. Sensors were used to record detailed
water use data at about 10 percent of the households.
7. The 12 study sites were Boulder, Colorado; Cambridge and Waterloo,
Ontario, Canada; Denver, Colorado; Eugene, Oregon; Las Virgenes, California;
Lompoc, California; Phoenix, Arizona; San Diego, California; Scottsdale and
Tempe, Arizona; Seattle, Washington; Tampa, Florida; and Walnut Valley,
California.
8. See Residential End Uses of Water, American Water Works Association
Research Foundation (1999), p. xviii.
9. On May 23, 2000, the Department of Energy reached an agreement with
appliance manufacturers and environmental and energy conservation
organizations to phase in water and energy efficiency standards for clothes
washers beginning in 2004.
10. For the purpose of this report, we focused on low-flow toilets--the
fixtures that (1) have the greatest potential for water savings and (2) have
been subject to the most complaints regarding their performance.
11. As a general principle, state and local regulations or ordinances
"revive" (i.e., are automatically reinstated) under these circumstances.
However, this principle may be applied differently or not at all, depending
on the law of a particular state. State officials in Texas and city
officials in Phoenix, Arizona, expressed concern that their state
legislatures might resume previous attempts to repeal their state standards
if the national standards were no longer in place.
12. The criteria used to select these locations included (1) water
efficiency standards that preceded the national standards, (2) the use of
rebate and/or retrofit programs to accelerate the installation of low-flow
toilets and other water-efficient fixtures, and (3) an assessment of the
programs' impact on water consumption.
13. Communities in California currently using "retrofit on resale" programs
include the Cambria Community Services District, Los Angeles, the North
Marin Water District, San Diego, San Francisco, and Santa Monica.
14. In May, we reported that the estimated reduction in wastewater flows by
2020 was about 25 percent, according to the preliminary results of an
EPA-sponsored study. (See Water Infrastructure: Impact of National Water
Efficiency Standards, GAO/RCED-00-161R , May 1, 2000.) At that time, to
compute the percent reduction in wastewater flows, we used data on total
U.S. flows at publicly owned treatment works from EPA's 1996 Clean Water
Needs Survey Report to the Congress, table C-3, the most recent data
available. Since then, EPA has provided a better approximation of future
wastewater flows, and the agency's estimate of the projected reduction in
wastewater flows has been revised with more conservative assumptions. In
addition, the availability of yearly projections of the reductions in
wastewater flows from the agency's contractor allowed us to use data for
2016, consistent with the time period for EPA's estimate of wastewater flows
to publicly owned treatment works.
15. Project costs include the cost of capital investments, energy, and
treatment chemicals.
16. Infiltration occurs when water gets into the system as a result of
groundwater that seeps into damaged sewer lines. Inflow is water that enters
the system through stormwater drains.
17. Submetering is metering for units that are a part of a larger service
connection, such as apartments in a multifamily building.
18. Officials from EPA's Office of Ground Water and Drinking Water and
Office of Wastewater Management told us that with the exception of the needs
reported by a few larger utilities, the needs estimates do not factor in the
impact of using water-efficient plumbing fixtures on projected capacity
needs. The Office of Wastewater Management is revising its reporting
instructions for its next needs survey so that the estimates submitted by
local wastewater utilities will consider the impact of the standards in the
future. Similarly, according to one official, the Office of Ground Water and
Drinking Water will consider revising its reporting instructions for future
surveys.
19. See 1996 Clean Water Needs Survey Report to Congress, U.S. Environmental
Protection Agency (1997).
20. See Drinking Water Infrastructure Needs Survey: First Report to
Congress, U.S. Environmental Protection Agency (Jan. 1997).
21. See Clean & Safe Water for the 21st Century, Water Infrastructure
Network (2000).
22. Other sources of federal financial assistance for water and wastewater
infrastructure include the U.S. Department of Agriculture's Water and Waste
Disposal program and the Department of Housing and Urban Development's
Community Development Block Grant program.
23. We reviewed several surveys of participants in accelerated toilet
replacement programs; generally, the participants were asked to rate the
performance of their low-flow toilet in specific areas and compare it with
the higher-volume toilet it replaced.
24. Under this test, known as a mixed media test, a combination of sponges
and paper balls must be discharged from the toilet bowl in a prescribed
number of flushes.
25. In one case (Palm Beach, Florida), our contact was limited to verifying
local standards for water-efficient plumbing fixtures; we did not conduct a
semistructured interview to discuss other issues.
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