EPA
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Water Sense
EPA 832-F-08-054
May 2008
ft A DAY IN THE LIFE OF A DROP
Worksheet #2
This exercise is designed to show how each member of your family uses water in
the bathroom. The bathroom is a small room where many of us waste a HUGE
amount of water! Using this worksheet, you will learn to calculate each family
member's average daily water use (about how much they use each day) for the
bathroom sink, the shower, the bathtub and the toilet. Follow the instructions
below to calculate each person's average daily water use.
Preparation
(. Prepare one Water Use Table for each day of the week. You will need one sheet for each day
(and one for each bathroom). Enter the day of the week at the top of the sheet where it
says "Today is:" and fill in each person's name across the row called "Family Members." Post
today's table in the bathroom with a pen or pencil and either a timer or clock. (Try to find a
spot where the sheet will stay relatively dry, but remember that you should never put paper
on hot things such as heaters, vents, radiators, curling irons, etc.) Once you get the OK from
your parents about where you're going to keep the sheet, make sure everyone is aware of
where the sheet is for each bathroom.
1. Ask each member of your family to record the number of minutes they use the faucet and the
shower and the number of times they flush the toilet or take a bath. (Note that for the toilet
and the bathtub, you are recording the actual number of times you flush the toilet or take a
bath, notthe number of minutes you are using them.)
IMPORTANT NOTE FOR ROW D: The cells in Row D are split so you can fill out information
for more than one bathroom, if you need to. Study the diagram below so you'll know where
to put your answers.
The top half will be the total
# of gallons of water used
by one person for the whole
week for ONE bathroom.
The lower, right half will be
for the total # of gallons of
water used by that person
for the whole week for ALL
bathrooms.
Figure 1
If you only have one bathroom in your home, you can leave the lower, right half of the
cells in Row D blank.
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CALCULATIONS
A. TOTAL # OF MINUTES OR USES PER PERSON, PER FIXTURE,
PER DAY
Find the total number of minutes or uses for each person for each fixture in the bathroom each
day by completing the following steps:
For parts A1-4 below, record your final answers in each Water Use Table in the row called "Total #
of minutes or uses per person, per fixture, per day"/n the appropriate column for each fixture.
A1. Add up the number of minutes each person used the faucet each day.
A2. Add up the number of minutes each person used the shower each day.
A3. Add up the number of times each person took a bath each day.
A4. Add up the number of times each person flushed the toilet each day.
Example: Audrey adds up each of the numbers her mom recorded when she used the faucet on
Monday. 1.5+ 14 + 4= 19.5 On the Water Use Table, Audrey records 19.5 in her mom's faucet
column in the row called "Total # of minutes or uses per person, per fixture, per day."
B. TOTAL # GALLONS PER PERSON, PER FIXTURE, PER DAY
Find the total number of gallons of water each person used for each fixture in the bathroom each
day by completing the following steps:
For parts 67-4, record your answers in the row of each Water Use Table called "Total # gallons per
person, per fixture, per day"/n the column for each fixture.
B1. Total Faucet Water Use
If you do not have a high-efficiency faucet, multiply each person's total number of minutes of
use for the sink faucet (Answer to A1) by the number 2.2 (which equals the maximum number of
gallons per minute for an average faucet).
If you have a high-efficiency or WaterSense®-labeled faucet, multiply each person's total number
of minutes of use for the faucet (Answer to A1) by 1.5 (the maximum number of gallons per
minute used by most high-efficiency faucets). This will give you the number of gallons each
person uses the faucet per day.
Example: First Audrey finds out what kind of faucet she has. She asks her mom to help her and
learns that she does not have a high-efficiency faucet, so she multiplies 19.5 (her answer to
port/47, the number of minutes her mom used the faucet on Monday) by 2.2 to find that her
mom used about 42.9 gallons of water from the faucet on Monday. She records her answer on
the Water Use Table in the row called "Total # gallons per person, per fixture, per day."
If Audrey had a high-efficiency faucet, she would have multiplied by 1.5 to find that her
mom would have used only 29.3 gallons of water from the faucet for Monday. Wow! What a
difference! If she had a high-efficiency faucet, Audrey's mom could have saved more than 13V2
gallons of water just from the faucet in one day!
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B2. Total Shower Water Use
Next you'll need to make the same calculation for the showerhead. If you have a regular
showerhead, multiply each person's total number of minutes of use for the shower (answer to A2)
by the number 2.5 (average number of gallons per minute used by an average showerhead).
If you have a high-efficiency shower head, multiply each person's total number of minutes of use
for the shower (answer to A2) by the number 1.5 (maximum number of gallons per minute used by
most high-efficiency showerheads). This will give you the number of gallons each person uses the
shower per day.
B3. Total Bath Water Use
To find the number of gallons used for baths per day, multiply your answer to A3 for each person
(total number of baths per day) by 40, the average number of gallons of water used per bath. This
will give you the number of gallons each person uses in bath water each day.
B4. Total Toilet Water Use
To find the number of gallons of water each person uses by flushing the toilet you'll first need to
complete the following steps.
1. First, have your parents help you find out how old your toilet is. Most toilets will have a
stamp in the porcelain that tells you what year it was made. If you can't find it, you'll have to
estimate.
2. Next, multiply each person's total number of uses for the toilet for each day (your answers to
A4 for each person) by the number of gallons of water for a toilet in the same age range as
yours. Use this guide below to figure out what number to multiply by:
a. If your toilet was made before 1982, multiply your answer to A4 (number of times each
person used the toilet each day) by 6.
b. If your toilet was made between 1983 and 1993, multiply the answer to A4 by 3.5.
c. If your toilet was built after 1994 (or you know that you have a high-efficiency model),
multiply the answer to A4 by 1.6.
d. If you have a WaterSense-labeled toilet, multiply the answer to A4 by 1.28
These calculations will result in the total number of gallons used per person by flushing the toilet
each day.
Example: First Audrey found out how old her toilet is. She and her mom looked to see if they
could find a stamp with the date on it. There was one! It said 1987. After looking at the chart
to see how many gallons of water a toilet made in 1987 uses per flush, Audrey knew that she
needed to multiply her mom's number of uses for Monday (5) by 3.5. When she made this
calculation, she found that her mom used 17.5 gallons of water from the toilet on Monday.
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By comparison, if Audrey's toilet was a WaterSense toilet, her mom would only have used 6.4
gallons of water! That's only about 1/3 of the water her older toilet uses!
TOTAL # GALLONS PER PERSON, PER DAY
Once you have all the daily totals for the gallons of water each family member has used from
each fixture for the day, you'll need to add them up for each person to get their daily total.
For part C, record your answers in the row of each Water Use Table called 'Total # gallons per
person, per day."
Example: Audrey found that her mom used 42.9 gallons of water from the faucet, 18 gallons
from the shower, 0 gallons from the bath and 17.5 gallons from the toilet. When she added them
up, she found that her mom used 78.4 gallons of water on Monday.
If Audrey had all high-efficiency fixtures in her home, her mom's total would have been 53.7,
which is 24.7 gallons or about 1/3 less water every day!
TOTAL # GALLONS PER PERSON, PER WEEK
At the end of the week, add up the number of gallons used by each person for each day. Record
your answer for each person in the row called "Total # gallons per person, per day."
IMPORTANT: If you have more than one bathroom, remember to add the number of gallons for
each bathroom first, and record that total on each sheet. Then add each bathroom together to get
your total and record this answer in the lower half of the divided cells in Row D as seen in Figure 1.
Example 1: After finishing her calculations for #4, Audrey found that her mom used:
Monday:
Tuesday:
Wednesday:
Thursday:
Friday:
Saturday:
Sunday:
78.4 gallons
76.0 gal Ions
82.2 gallons
76.0 gal Ions
81.0 gallons
88.0 gal Ions
96.0 gal Ions
577.6 gallons
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Example 2: If Audrey had two bathrooms in her house, she would have two sets of answers. In
that case, her calculations would look like this.
Bathroom 1
Monday:
Tuesday:
Wednesday:
Thursday:
Friday:
Saturday:
Sunday:
TOTAL:
72.0 gallons
20.0 gallons
18.0 gallons
15.0 gal Ions
9.0 gallons
21.0 gallons
30.0 gallons
125.0 gallons
Monday: 66.4 gallons
Tuesday: 56.0 gallons
Wednesday: 64.2 gallons
Thursday: 61.0 gallons
Friday: 72.0 gal Ions
Saturday: 67.0 gallons
Sunday: 66.0 gallons
TOTAL: 452.6 gallons
77?ese two totals would go in the upper left corner of the sheets for each bathroom. Then Audrey
would add them together to get the combined total of 577.6, which would go in the lower, right
half of the answer square in the row called 'Total # gallons per person, per week."
£. AVERAGE # GALLONS PER PERSON PER DAY
Divide the answer to part D (Total gallons per person per week) for each person by 7 (or, if you
did not conduct the exercise for a full week, divide by the number of days you conducted the
activity). This number is the average number of gallons each person uses per day. Record your
answers in the row called "Average # gallons per person per day" in the table.
BONUS: Find out how much water your whole family uses every day! Add up the answers to
part D (Total # gallons per person per day) for each family member and divide by the number of
family members who participated. Audrey's family uses more than 550 gallons of water everyday.,
yikes! Looks like it's time for Audrey's family to start learning how to use water more efficiently!
We can all do a better job of using water efficiently.
Check out the Pledge to Filter out Bad Water Habits and learn how to start
filtering out your bad water habits today!
To learn more about using water more efficiently, go to
EPA's WaterSense Web site where there is a section just for kids!
www.epa.gov/watersense/kids/index.htm
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