Executive Summary
Wastewater Flows from Single Family Dwellings
Study done for the Michigan
Technical Advisory Council for Onsite Wastewater Treatment
Danielle N. McEachin and Ted L. Loudon
Student Intern and Professor, respectively,
Agricultural Engineering Department
Michigan State University
The
purpose of this study was to collect, organize and present what is known about
the amount of wastewater that can be expected to flow from dwellings. The goal is to provide designers and
regulators with an actual flow based data set from which to develop design flow
numbers for sizing systems. The data in
this document comes from a variety of sources.
Most were found on the Internet, some were found in the library, and
others were provided from file data collected by entities in Michigan. The study was restricted to data collected
during the years 1980-2000, so that the values determined would be
representative of life styles of the present generation. In fact, only two numbers in the data tables
are from before 1987.
A group of studies providing
metered home water use rates presented in units of gpd per capita from around
the country were reviewed and summarized.
When averages were weighted based on the number of homes per study, the
overall weighted average per capita daily water use was just under 51 gpd
(Table 1). The value of this data is
limited by the fact that much of the data was total use, including outdoor
water use, and had to have a correction factor applied. Numerous sources containing recommended per
capita design flows were reviewed. Most
recommendations are in the 50-70 gpd/c range (Table 4).
Perhaps the most valuable
data is data gathered in Michigan. A
study of metered data from 700 homes in southern Michigan showed an average
daily use per home of 214.3 gallons.
The three bedroom home average was 221.3 gpd (74 gpd/br) and the four
bedroom average was 285.5 gpd (71 gpd/br).
A study of measured flows from 66 homes in Jackson County showed flows
of 56 gpd per bedroom.
Average per person flows,
averaged over large numbers of people, appear to be in the 50-55 gpd/c
range. Average flows expressed per
bedroom, for 3-4 bedroom homes appear to be in the 70-75 gpd/br range. While bedrooms do not generate flow, people
do, it is common to design on the basis of number of bedrooms since occupancy
varies. For large clusters of homes,
designing on the basis of 75 gpd/br would appear to be supported by the data
available. For an individual home
design, a significant safety or peaking factor must be applied. Many of the references consulted suggest a
factor of 2 or even 2.5. Use of a high
design flow for individual homes helps to compensate for the state of the art
in site evaluation and the occasional high water use occupancy.
The Technical Advisory
Council will produce a companion guidance document providing recommendations
for applying this data in design recommendations.
Wastewater Flows from Single Family Dwellings
Study done for the Michigan Technical Advisory
Council for Onsite Wastewater Treatment
Danielle N. McEachin and Ted L. Loudon
Student Intern and Professor, respectively,
Agricultural Engineering Department
Michigan State University
Purpose: Rational design of wastewater treatment and
dispersal systems is based on the flow that the system must be able to handle.
This is usually expressed on a daily flow basis and typically includes a factor
of safety which is large for individual home systems and may be reduced as
systems are clustered together. The
purpose of this study was to collect, organize and present what is known about
the amount of wastewater that can be expected to flow from dwellings. The goal is to provide designers and
regulators with an actual flow based data set from which to develop design flow
numbers for sizing systems.
The data in this document
comes from a variety of sources. Most
were found on the Internet, some were found in the library, and others were
provided from file data collected by entities in Michigan. Every effort was made to ensure that the data
reflect indoor water use, which eliminates most consumptive uses and represents
the flow that would be expected in the wastewater system. Because consumptive uses are hard to
eliminate completely, particularly in arid climates, we restricted our data to
the more humid states. One exception is
that a study from Denver, CO is included in which a significant effort was made
to eliminate outdoor consumptive uses in the design of the study. The numbers in the Colorado study are higher
than those from more humid states but we cannot determine exactly what the
reason for this might be. Wherever
total water use numbers were encountered they were multiplied by a factor of
0.70 to give indoor water use only.
These values are indicated by a *.
This factor is based on the findings of multiple studies which measured
both indoor and outdoor usage. We
restricted our selection of data to include only data collected during the
years 1980-2000, so that the values determined would be representative of life
styles of the present generation. In
fact, only two numbers in the data tables are from before 1987, and these are
from a study deemed to be sufficiently reliable that we did not wish to exclude
it.
The data are divided into
four tables. Table 1 contains data from
literature and internal sources that were obtained through actual
measurement. This means that the
numbers were derived from meter readings at occupied residences. These numbers are from studies where
multiple homes were metered and the indoor water use was determined. Only some of these studies reported indoor
water use only. For those where the
reported values were total use, the 0.70 factor was used to obtain indoor water
use numbers. See footnotes following
the tabulated data for the basis of this factor. The study done by the American Water Works Association Research
Foundation metered 1188 homes to obtain their data. The Denver Board of Water Commissioners metered 5649 homes in the
city and county of Denver.
The U.S. Department of
Housing and Urban Development has conducted many studies on residential water
use. In some of their work, they
designed studies to obtain as diverse a group of homes as possible by gathering
data on each household through issuing a questionnaire to each resident. Their study entitled “Water Saved by
Low-flow Fixtures” included water meter data from over 200 homes. They also conducted a study of flow from
apartment buildings in which they collected data from 23 buildings. The apartments were noted to be especially leaky
and they found unusually high per capita water use. The U.S. Geological Survey published a table with water use
values for every state. We selected
data from the more humid states and applied the 0.70 factor to obtain indoor
water use values. Data were collected
from homes where the water supply was from both self-supplied (SS) and
public-supplied (PS) sources.
Table 2 contains data that
was found through actual measurement but is presented as gallons per day per
home. The Michigan study done by Equinox
Inc. for use in the design of the Mill Valley Condominium Subdivision metered
over 700 homes in Livingston and Oakland counties and determined average water
use per dwelling. The first 7 entries
in Table 2 represent flows averaged over multiple single family dwellings and
would be representative of flows to be expected from a cluster of homes. The average flow equals 159 GPD/home over
640 homes. The Michigan Department of
Environmental Quality study involved determination of metered flows from over
500 homes in Oakland County and Highland Township. Both of these Michigan studies are believed to be highly reliable
but resulted in per home flows that were higher.
Table 3 contains data found
through actual measurement but the values were presented in the original
studies in units of gallons per day per bedroom. This data is from a study done by the Michigan Department of
Environmental Quality. In this study,
66 homes were metered in Jackson County and the size of home determined so that
the data could be presented in terms of a per bedroom water use average.
Table 4 contains data from
publications which give representative numbers that are recommended for design
of wastewater systems. These are not
well referenced so it is unclear whether they originally came from actual use
studies or are estimates, possibly including a safety factor, that are simply
repeated from another publication.
These sources were mostly found on the Internet.
After the tables are a set
of statements and observations gleaned from literature. The effect of income level and household
size on water use is analyzed. Our
reasons for using the 0.70 factor are given, a comparison of self-supplied and
public-supplied water use is given.
Typical times of peak water use are analyzed as are the effects of
metering and water pressure.
Conclusions that can be
drawn:
From Table 1, the per capita
metered indoor water use data from nationwide studies show an average value of
69 gallons per person per day. The per
capita data obtained by applying the 0.70 factor to total water use data found
in humid climates shows an average value of 55.2 gallons per day, with a
self-supplied average of 50.5, a public-supplied average of 57.7 and a range of
35-86.8. The weighted average per capita water use data for all homes in Table
1 show an overall average use of 50.7 gallons per day, with a self-supplied use
of 51.1 and a public-supplied use of 50.47.
The per home metered indoor
data in Table 2 shows an average of 214.3, with a 3 bedroom average of 221.3, a
4 bedroom average of 285.5 and a range of 140-327. The first 7 entries in Table 2 represents measured flow data from
640 Michigan homes and shows an average of 159 GPD/home.
The nationwide data sets
show somewhat higher per capita water use.
Humid region data suggest that average per capita indoor water use
averages between 50 and 70 gpd. Total
water use per home averages between 160 and 285 GPD with the larger figure for
larger homes.
This should be considered a
work in progress. We would like to
include additional data. If the reader
has or is aware of additional data that could be included, we would like to
receive it. This summary will be
modified if additional data are received or otherwise located.
Residential Water Consumption Data, From
a Variety of Sources
Report by: Danielle McEachin
Table
1. Sources whose data was found by actual measurement, measured in GPD/Person
|
Sponsor
|
Source
|
Study
|
Area
of Study
|
Time
Period
|
Indoor
use or Total use?
|
Type
of Dwelling
|
Per
capita daily water use
|
|
AWWA
Research Foundation
|
http://www.awwarf.com/exsums/90781.htm
|
Residential
End Uses of Water [Project#241]
|
12
study sites, across the U.S.
|
Copyright1999
|
Indoor
|
1,188
Single-family homes
|
69.3,
Including Leakage
|
|
Denver
Board of Water Commissioners
|
Litke
and Kauffman, “Analysis of Residential Use of Water in the Denver
Metropolitan Area, CO, 1980-87
|
16
groups of homes in the city and county of Denver
|
Data
From 1980-87
|
Indoor
|
5,649
Single-family homes
|
64-119
Mean = 85.6
|
|
Rhode
Island Governor’s Office of Housing, Energy, and Intergovernmental Relations
|
M.
A. Horn, P.A. Craft & Lisa Bratton, “Estimation of Water Withdrawal and
Distribution, Water Use, and Wastewater Collection and Return Flow in
Cumberland, Rhode Island, 1988
|
Cumberland,
Rhode Island
|
Data
From 1988
|
Indoor
and Total
|
Single-family
homes
|
70
SS (Total)
77
PS
(Indoor)
& 90 PS (Total)
|
|
U.S.
Department of Housing and Urban Development, Office of Policy Development and
Research
|
Brown
and Caldwell, “Residential Water Conservation Projects, Summary Report”, 1984
|
Water
Saved by Low-flow Fixtures
|
Nationwide
|
Data
from 1983
|
Indoor
|
200
Single-family homes
|
66.2
|
|
Retrofit
of Apartment Buildings
|
Washington, D. C.
|
Data
From 1981
|
Indoor
|
23
Apartment buildings
|
100**
Including Leakage
|
Table
1. (cont.)
Sponsor
|
Source
|
Study
|
Area
of Study
|
Time
Period
|
Indoor
use or Total use?
|
Type
of Dwelling
|
Per
capita daily water use
|
|
United
States Geological Survey
|
http://water.usgs.gov//watuse/tables/dotab.st.html
|
Table12.
Domestic Freshwater Use by State
(States chosen with humidity similar to that of Michigan)
|
Alabama
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
52.5*
SS
70*
PS
|
|
Arkansas
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
61.6*
SS
74.2*
PS
|
|
Connecticut
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
52.5*
SS
49*
PS
|
|
Delaware
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
55.3*
SS
54.6*
PS
|
|
Georgia
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
52.5*
SS
80.5*
PS
|
|
Illinois
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
58.8*
SS
63*
PS
|
|
Indiana
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
53.2*
SS
53.2*
PS
|
|
Kentucky
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
35*
SS
49*
PS
|
|
Louisiana
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
58.1*
SS
86.8*
PS
|
|
Maine
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
63*
SS
40.6*
PS
|
|
Maryland
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
58.1*
SS
73.5*
PS
|
|
Massachusetts
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
50.4*
SS
46.2*
PS
|
|
Michigan
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
51.1*
SS
53.9*
PS
|
|
Mississippi
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
35*
SS
86.1*
PS
|
Table
1. (cont.)
|
Sponsor
|
Source
|
Study
|
Area
of Study
|
Time
Period
|
Indoor
use or Total use?
|
Type
of Dwelling
|
Per
capita daily water use
|
|
United
States Geological Survey
|
http://water.usgs.gov//watuse/tables/dotab.st.html
|
Table12.
Domestic Freshwater Use by State
(States chosen with humidity similar to that of Michigan) (cont.)
|
Missouri
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
42*
SS
59.5*
PS
|
|
New
Hampshire
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
45.5*
SS
49.7*
PS
|
|
New
Jersey
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
52.5*
SS
52.5*
PS
|
|
New
York
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
40.6*
SS
83.3*
PS
|
|
North
Carolina
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
38.5*
SS
39.9*
PS
|
|
Ohio
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
52.5*
SS
37.5*
PS
|
|
Pennsylvania
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
36.4*
SS
43.4*
PS
|
|
Rhode
Island
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
49*
SS
46.9*
PS
|
|
South
Carolina
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
52.5*
SS
53.2*
PS
|
|
Tennessee
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
45.5*
SS
59.5*
PS
|
|
Vermont
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
50.4*
SS
56*
PS
|
|
Virginia
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
52.5*
SS
52.5*
PS
|
|
West
Virginia
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
56*
SS
51.8*
PS
|
|
Wisconsin
|
Data
From 1990
|
Indoor
|
Single-family
homes
|
42.7*
SS
36.4*
PS
|
Table
1. (cont.)
|
Sponsor
|
Source
|
Study
|
Area of Study
|
Time
Period
|
Indoor
use or Total use?
|
Type
of Dwelling
|
Per
capita daily water use
|
|
United
States Geological Survey
|
http://oh.water.usgs.gov/water_use/95huc.html
|
Estimated
Water Use for Ohio, 1995, by Hydrologic Cataloging Unit
|
Ohio
|
Data
From 1995
|
Indoor
|
Single-family
homes
|
70
SS*
50
PS*
|
|
Michigan
Department of Public Health
|
Oakland
County Water Use/Population Study
|
Oakland
County, MI
|
Data
From 1991
|
Total
|
151
2 bedroom homes
|
56.7*
|
|
445
3 bedroom homes
|
49*
|
|
186
4 bedroom homes
|
51.8*
|
|
30
5 bedroom homes
|
57.4*
|
SS = Self-supplied Average per capita indoor water use =
50.76
PS
= Public-supplied SS average per capita indoor water use
= 51.1
*Converted
to Indoor Use From Total Use by using the formula Indoor Use = (0.70) Total Use PS average per capita indoor water use = 50.47
** This
study stated these apartments to have an especially large amount of leakage and Range of per capita water use = 35-100
therefore the numbers from these
apartments were not used in any averages
Table
2. Sources whose data was found by actual measurement, measured in GPD/Home
|
Sponsor
|
Study
|
Area
of Study
|
Time
Period
|
Indoor
use or Total use?
|
Type
of Dwelling
|
GPD/
Home
|
|
Equinox,
Inc., Stephens Consulting, Inc.
|
Daniel
C. Schrauben and David R. Beschke, “Basis of Design, Flow Adjustment,
Wastewater System, Mill Valley Condominium Subdivision”, June 17, 1999.
|
Deer
Creek
|
Data
From 1990
|
Indoor
|
3
single-family homes
|
148
|
|
Greenock
Hills No. 3
|
Data
From 1990
|
Indoor
|
20
single-family homes
|
158
|
|
Lake
Tyrone
|
Data
From 1990
|
Indoor
|
182
single-family homes
|
165
|
|
Portage
Bay
|
Data
From 1990
|
Indoor
|
20
single family homes
|
140
|
|
Runyan
Lake
|
Data
From 1990
|
Indoor
|
274
single-family homes
|
164
|
|
Sandy
Creek
|
Data
From 1990
|
Indoor
|
5
single-family homes
|
154
|
|
Tanglewood
|
??
|
Indoor
|
136
single-family homes
|
145
|
|
City
of Novi
|
Data
From 1990-1992
|
Indoor
|
4
bedroom home
|
327
|
|
City
of Novi
|
Data
From 1990-1992
|
Indoor
|
3
bedroom home
|
234
|
|
Eagle
Ravine
|
Data
From 1990
|
Indoor
|
8
Single-family homes
|
270
|
|
Milford
Bluffs
|
Data
From 1990
|
Indoor
|
3
bedroom home
|
222
|
|
Milford
Bluffs
|
Data
From 1990
|
Indoor
|
4
bedroom home
|
255
|
|
Settler’s
Pointe
|
Data
From 1990
|
Indoor
|
3
bedroom home
|
213
|
Table
2. (cont.)
|
Sponsor
|
Study
|
Area
of Study
|
Time
Period
|
Indoor
use or Total use?
|
Type
of Dwelling
|
GPD/
Home
|
|
Equinox,
Inc., Stephens Consulting, Inc.
|
Daniel
C. Schrauben and David R. Beschke, “Basis of Design, Flow Adjustment,
Wastewater System, Mill Valley Condominium Subdivision”, June 17, 1999.
(cont.)
|
Settler’s
Pointe
|
Data
From 1990
|
Indoor
|
4
bedroom home
|
281
|
|
Village
of Milford
|
??
|
Indoor
|
4
bedroom home
|
209
|
|
Village
of Milford
|
??
|
Indoor
|
3
bedroom home
|
206
|
|
Michigan
Department of Public Health
|
Oakland
County Water Use/Population Study
|
Oakland
County, MI
|
Data
From 1991
|
Total
|
3
Bedroom home
|
197
|
|
4
Bedroom home
|
257
|
|
Highland
Township, Four Bedroom and Three Bedroom Water Usage Comparison
|
Highland
Township
|
Data
From 1993
|
Total
|
3
Bedroom home
|
256
|
|
4
Bedroom home
|
284
|
Average per home indoor
water use (all homes) = 214.3
Average
indoor water use (3 bedroom homes) = 221.3
Average
indoor water use (4 bedroom homes) = 285.5
Range
of indoor water use (all homes) = 140-327
|
Sponsor
|
Study
|
Area
of Study
|
Time
Period
|
Indoor
use or Total use?
|
Type
of Dwelling
|
GPD/ Bedroom
|
|
Michigan
Department of Public Health
|
Engineering
Company Review of One Subdivision, Jackson County
|
Jackson
County
|
Data
From 1991
|
Total
|
66
single-family homes (3 & 4 bedrooms)
|
56
|
SS
= Self-supplied Range
of per capita water use for homes = 40-79
PS
= Public-supplied
*Converted
to indoor use from total use by using the formula Indoor Use = (0.70) Total Use
Interesting Observations on the Effects of Some Factors on Water Use
-
Water-conserving
toilets were shown to leak more often than non-conserving ones in the “Water
Saved by Low-flow Fixtures” study done by the U.S. Department of Housing and
Urban Development.
-
Effects
of income level and household size on water use:
-
To
determine the effects of income on residential water use, the study “Water
Saved by Low-flow Fixtures” by the U.S Department of Housing and Urban
Development compared the average interior water use in gallons per capita-day
for each household with the average income range for that household. The scatter plot of this data showed a wide
variation of per capita water use within each income range.
-
The
average interior water use values for each income bracket were also compared,
and showed little or no correlation between income and water use.
-
In
this same study, the average interior water use in gpcd was compared with
household size. A wide variation of
water usage within each household size was observed. However, the comparison of average interior water use for each
group of household sizes did show a decreasing trend in per capita use as the
number of people in the house increased.
-
If
outside use were also included in this study, a correlation between income and
water use would most likely be observed, due to bigger yard size and pools.
-
In
the study, “Analysis of Residential Use of Water in the Denver Metropolitan
Area, Co”, it was found that Indoor water use correlated best with persons per
household and that correlation with assessed value was very low.
-
The
Oakland County Water Use/Population Study also showed little or no correlation
between assessed value and water use.
-
It
is interesting to note, however, that homes with low incomes may not have
washing machines or dishwashers, while homes with higher incomes usually
do. This could have a great effect on
water use.
-
Indoor
water use as a function of total water use:
-
Indoor
water use is said to be about seventy-five percent of total water use in the
document, “Focus on Residential Water Conservation” by the North Carolina
Cooperative Extension Service.
-
The
book “Small and Decentralized Wastewater Management Systems” states that, “If a
community has a water system but not a wastewater collection system, the
average wastewater flow-rate can be estimated by multiplying the water use by a
factor of sixty-eighty percent, depending on the landscaping.” This is approximately equivalent to saying
that base water use is sixty-eighty percent of total water use.
-
The
Oakland County Water Use/Population Study shows a difference between winter and
summer water use of sixty-six percent.
-
Based
on these observations some of the total water use data in the above table was
multiplied by a factor of 0.70 to get the indoor water use.
-
The
study “Analysis of Residential use of Water in the Denver Metropolitan Area,
Co” states that, “Water used to grow lawns in Denver is forty-two percent of
water consumption.” This is because
Colorado is a very dry state.
-
Times
of peak water use:
-
In
the study, “Analysis of Residential Use of Water in the Denver Metropolitan
Area, Co”, it is stated that, “more water is used in the summer, on Sundays,
and from 7 a.m.– 9 a.m.”
-
On
the EPA’s website “How Much Drinking Water Do We Use In Our Homes?”, it states
that
-
The
lowest rate of use is from 11:30 p.m. to 5:00 a.m.
-
There
is a sharp rise in use from 5:00 a.m. to noon, with a peak hourly use from 7:00
a.m. to 8:00 a.m.
-
There
is a moderate use from noon to 5:00 p.m., with a lull around 3:00 p.m.
-
There
is an increase in use in the evening from 5:00 to 11:00 p.m., with the second
minor peak from 6:00 to 8:00 p.m.
-
Metered
versus flat rate customers:
-
The
study, “Water Saved by Metering”, done by the U.S. Department of Housing and
Urban Development compares metered customers’ water use with that of flat rate
customers.
-
Denver
is unique because it has both metered and flat rate customers. Since 1957, all new homes have been required
to be metered. In spite of this, most
customers are flat rate because they pre-existed this policy. Because of this, nearly identical homes in
the same area can have different billing
systems.
-
To
study the effect of metering, one group of twenty-five metered homes and two
groups of flat-rate homes (forty-two homes total) were identified, and there
water use data collected for a period of three-years.
-
The
test groups were selected so those factors such as fire hydrants and downstream
water uses were eliminated.
-
Over
the three-year period of data collection, water use in metered homes averaged
about 453 gallons per day (total, 42% is yard watering), and water use in
flat-rate homes averaged about 566 gpd.
Thus, metered homes used twenty-percent less water than flat-rate
homes.
-
The
basic effect of metering is to reduce the amount of water used for
irrigation. Therefore, water use would
be reduced more in a dry area such as Denver than a more humid area.
-
Effect
of water pressure on water use:
-
Reducing
water pressure can be one means of reducing water use. A decrease in water pressure causes a
decrease in water flow related to the square root of pressure drop.
-
Many
water use appliances regulate the volume of water they use, eliminating the
effect of water pressure. Water pressure does, however, have an effect on water
leakage and outdoor water use.
-
The
U. S. Department of Housing and Urban Development did a study on water pressure
entitled, “Effect of Water Pressure on Water Use”, in which they studied
different pressure zones in Denver, Los Angeles, and Atlanta. They found a difference of about two-three
percent in the water use of homes with high compared to low pressure (difference
of about 35 psi).
-
Equations
Related to Water Use
-
The
book, “Small and Decentralized Wastewater Management Systems”, states that the
equation for flow from a residence can be given as: Flow, gal/home*day = 40
gal/home*day + 35 gal/person*day x (number of persons/home).
-
The
document, “Water Use”, given to me by Larry Stephens describes three types of
residences, with separate equations for estimating water use.
-
In
a Type I residence the total floor area of the residence divided by the number
of bedrooms is more than 800 square feet, or more than two of the following
water-use appliances are installed: automatic washer, dishwasher. In a Type I residence the estimated water
use is equal to 150 gpd/bedroom. This
assumes an occupancy of two people per bedroom, each using 75 gpd.
-
In
a Type II residence the total floor area of the residence divided by the number
of bedrooms is more than 500 square feet and there are no more than two
water-use appliances. Water use in a
Type II residence is obtained by multiplying 75 times a factor equal to the
number of bedrooms plus one.
-
In
a Type III residence the total floor area of the residence divided by the
number of bedrooms is more than 500 square feet and there are no more than two
water-use appliances. Water use in a Type III residence is obtained from the
formula: 66+38(number of bedrooms +1).
References
Anderson, Bill. 2000.
Water Use Trends on the Prairies. Prairie Water News Vol. 12, No. 1
(1992) August 2000. <http://www.quantumlynx.com/water/back/vol2no1/v21_st2.html>.
AWWA Research Foundation
Webpage. 2000. “Residential End Uses of
Water
[Project#241]”
June 2000 <http://www.awwarf.com/exsums/90781.htm>.
Brown and Caldwell. 1984. Residential Water Conservation
Projects, Summary Report. USDHUD.
University of Georgia. August 2000. Conserving Water At Home.
<http://hermes.ecn.purdue.edu/cgi/convertwq?6229>.
University of Maine. August 2000. Conserving Water At Home.
<http://hermes.ecn.purdue.edu/cgi/convertwq?6453>.
Auburn University. August 2000. Conserving Water, Developing Water-Conserving Habits: A
Checklist. <http://hermes.ecn.purdue.edu/cgi/convertwq?7696>.
Crites, Ron and
Tchobanoglous, George, “Small and Decentralized Wastewater
Management Systems”, 1999.
R. L. Peeks Pump Sales. July 2000.
Domestic Wastewater Systems and Pump Talk.
<http://freehosting1.at.we.bjump.com/6eba64886/pu/pumpman
webjump/plan.htm>.
United States Geological
Survey. August 2000. Estimated Use of Water in the U. S. in
1990. <http://water.usgs.gov//watuse/tables/dotab.st.html>.
United States Geological
Survey. August 2000. Estimated Water Use for Ohio, 1995. <http://oh.water.usgs.gov/water_use/95huc.html>.
North Carolina Cooperative
Extension Service. August 2000. Focus on Residential Water Conservation.
<http://www.bae.ncsu.edu/bae/programs/extension/publicat/wqwm/he250.html.
University of Arkansas. August 2000. Home Water Use Management.
<http://hermes.ecn.purdue.edu/cgi/convertwq?7541>.
Horn, M.A., Craft, P.A.,
Bratton, Lisa. 1988. Estimation of Water Withdrawal and
Distribution,
Water Use, and Wastewater Collection and Return Flow in Cumberland, Rhode
Island. Rhode Island’s Governor’s
Office of Housing, Energy and Intergovernmental Relations.
United States Environmental
Protection Agency (EPA), Office of Water.
August 2000. How Much Drinking
Water Do We Use in Our Homes. <http://www.epa.gov/OGWDW/wot/howmuch.html>.
Michigan State University
Extension. July 2000. How to Conserve Water in Your Home and
Yard. <http://hermes.en.purdue.edu/cgi/convertwq?5373>.
Litke and Kauffman. 1988.
Analysis of Residential use of Water in the Denver Metropolitan
Area. Denver Board of Water
Commissioners.
Michigan Department of
Environmental Quality. 1999. Oakland County Water
Use/Population
Study, 1991, Highland Township Water Use Data, 1993, and Jackson County
Sanitary Flow Comparison.
Missouri Department of
Natural Resources Energy Center. August
2000. Residential Energy Efficiency. <http://www.dnr.state.mo.us/de/residential/waterusage.htm>.
Schrauben, Daniel and David
Beschke. 1999. Basis of Design Flow Adjustment, Wastewater
System Mill Valley Condominium Subdivision.
Equinox Inc. June 1999.
Polk County, Department of
Water Conservation. August 2000. Water Conservation For Kids. <http://www.co.polk.ia.us/departments/conserv/kids.asp.html>
U of Rhode Island. August 2000. Water Conservation In and Around the Home.
<http://hermes.ecn.purdue.edu/cgi/convertwq?6425>.
University of Maryland. August 2000. Water Conservation In the Home.
<http://hermes.ecn.purdue.edu/cgi/convertwq?5321>.
Unites States Geological
Survey. August, 2000. Water Resources Outreach Program Page. <http://water.usgs.gov/outreach/poster3/grade_school/Page7.html>.
_____________ Water Usage and Your Onsite Sewage
Treatment System. Individual Sewage
Treatment System (ISTS), Scott County, MN.
July 2000. <http://www.co.scott.mn.us/EH/ISTS/septic.htm>.
University of
Minnesota. August 2000. Water Use and Conservation.
<http://www.extension.umn.edu/distribution/youthdevelopment/components/0328-05.html>.
Kennewick Public Works
Department. July, 2000. 32 Tips on Water Conservation <http://www.ci.kennewick.wa.us/pw/watercom.htm>.