How to Drain or Backwash Your Pool
Hopping into your pool is one of the most refreshing things you can do
on those hot Arizona summer days! But,
the water safe and inviting for family and friends means proper treatment
and maintenance, including occasional backwashing or partial draining.
Unfortunately, pool water discharges can contain environmentally harmful
pollutants such as excess salts, elevated chlorine and other chemicals, and
even nuisances such as mosquito larvae.
Below, you'll find our steps and guidelines for draining
your pool properly in the City of Mesa. These guidelines also
apply when draining spas and fountains. It is best to consult
a pool professional to determine when it is necessary to drain your pool and
how often to do so.
Scroll below or jump down to
your topic of interest:
- Only Rain in the Storm Drain
- Properly Drain or Backwash Your Pool
- Locating Your Sanitary Sewer Cleanout
- Additional Options / Alternatives to Draining Your Pool
- Cleaning Pool and Spa Filters
- Frequent Questions About Draining Your Pool
You may also be interested
in our printable
brochure (NOTE: It does not contain all of the charts and
information provided below).
REMEMBER, ONLY RAIN IN THE STORM
A pool owner may be tempted to discharge pool water into the
street and gutter that leads to a storm drain. However, the purpose
of the storm drain system is to protect against flooding and water
damage by quickly removing rain water from our streets. This water
gets no treatment and may ultimately drain into washes, lakes,
retention basins, community parks, and can even make its way into
the Salt and Gila rivers. This is why the City of Mesa has
ordinances and programs to reduce pollutants into our storm drains
and why the disposal of swimming pool water to the City's
storm drain system is prohibited.
MThe ordinance does not allow you to drain
pool water into streets, catch basins, curbs, gutters,
ditches, channels, storm drains, and retention basins that
are owned and operated by the City.
your responsibility as a
property owner to ensure your property is in compliance with
IThe storm drain
system is completely separate from the sanitary sewer
system, which is designed to capture and treat wastewater
from sinks, toilets and other sources.
water discharge cannot be drained to city streets
or the storm drain system.
TO PROPERLY DRAIN OR BACKWASH
YOUR POOL WHILE PROTECTING THE ENVIRONMENT
You have two main options to drain or
backwash your pool:
OPTION 1 -
This is a great option since it allows you to reuse water you
already paid for and could reduce your landscape water use. Drain
your pool or spa water to your desert landscape, lawn or rocky areas
on your property and allow the water to percolate into the ground.
Be sure to use caution when applying pool water on certain plants
since it contains more salt and chlorine than tap water. See our
table of salt-sensitive plants below.
MSalt or saline pool water contains higher
concentrations of salts that can be more damaging to plants
MRemember to move the drain hose
frequently, since water discharge to one location can create
stagnant water areas that can attract mosquitoes. Also be
sure that the pool water does not flow onto your neighbor's
INotification or a permit is not required by the City of
Mesa when draining your pool.
See our table of salt-sensitive plants below!
OPTION 2 -
THE SANITARY SEWER
You can also drain or backwash your pool into your home's
sanitary sewer cleanout. Occasionally, an in-ground pool has a drain
line connected to the sanitary sewer. If not, then follow these
- Locate the sanitary sewer
cleanout on your property and remove the cap (if there
are two, use the one closest to the home - see Diagram
- Make sure that the pool
water is near neutral (pH 6-8), shut off the power to
the filtration system at the circuit breaker and turn
off the automatic water fill valve if you have one
(these steps will not be necessary if you are only
backwashing your pool).
- Run the drainage hose from a submersible pump in the
pool to the cleanout pipe and insert the hose a few
inches into the pipe. Be sure to secure the drain hose
so it won't pop out.
- Turn on the pump and
immediately check to make sure no water is backing up
into the house (check shower and tub drains first).
If the water backs up, turn off the pump immediately.
You may have a blockage, or have the flow rate set too
high. The recommended discharge rate is 12 gallons per
- Replace the sanitary sewer
cleanout cover when finished.
- Discharging into a sewer
- After draining your pool,
refill it as soon as possible since direct sunlight can
damage the plaster or lining if left exposed too
long.Check for proper chemical levels every day for a
week after refilling.
pool water or backwash in your landscape.
Discharging into a sewer cleanout allows Mesa
to treat and reuse your pool water.
New homes have two sanitary sewer cleanouts.
Always pick the one closest to the home.
MIf backwashing into the sewer cleanout, do not allow the
passage of soil, sediment, rock, sand, debris or other solid
material during the discharge. This could potentially create a
sanitary sewer overflow in the street and/or on your property.
MNever drain pool water into or toward a sanitary
sewer manhole installed in the street.
IOption 2 allows Mesa to treat
and reuse the water for landscape irrigation or groundwater
LOCATING THE SANITARY SEWER
|The sanitary sewer cleanout is commonly used by
plumbing professionals to clear sewer line backups. Look for a black
threaded cap about 3 to 4 inches in diameter with a raised square
nut on top. It is typically located outside at ground level next to
the house (often outside a bathroom or the kitchen). Look carefully,
as it may be hidden by landscaping. Older homes usually have only
one opening, while new homes have two cleanout pipes. Some homes
may have the cleanout located on an outside wall. See Diagram 1
IIf your neighborhood has alleys, your
cleanout may be in the backyard.
IIf you have trouble locating your sewer cleanout, or
have questions on safe flow rates, consult a plumber.
cleanouts can often get
covered by landscaping.
1. Typical locations of sewer cleanout near your home.
install the pool or backwash drain line as a permanent fixture. This
may violate City plumbing codes or County health regulations and and
could contaminate the water when you refill the pool.
MUsing a cleanout
in the wall is risky and the potential for water backing up is
ADDITIONAL OPTIONS / ALTERNATIVES
If your pool has
been subjected to serious contamination (for example, high
concentrations of chemical treatment products) or the water
cannot be disposed of under the other options previously
discussed, you may need to hire a contractor to pump you
pool into a water truck and dispose of it properly offsite.
Check the yellow pages or internet for septic disposal
companies for this service.
Consult a pool
professional for more information, but other alternatives
proper chemical levels in your pool to reduce the need
your pool professional to determine if repairs can be
made without draining the pool.
restoration systems that can be brought onsite and
eliminate the need to drain the pool (search the
internet for "treat calcium without draining pools").
can be pumped into a
CLEANING POOL AND SPA FILTERS
rules outlined above will apply when cleaning pool and spa
filters. Always be sure to follow the manufacturer's
-Cartridge filters should be rinsed over gravel, a lawn or
other vegetated area.
-Use a separation tank for diatomaceous earth (DE) and
cellulose fiber filters to capture the DE or fibers.
filter or fiber materials can be dried, bagged and
placed into your trash receptacle.
The same guidelines apply when
cleaning pool or spa filters.
FREQUENT QUESTIONS ABOUT DRAINING
HOW LONG DOES IT TAKE TO DRAIN A POOL?
The maximum recommended
discharge rate to your sanitary sewer is 12 gallons per minute, but
will depend on the size of the drain line, distance to the sewer
main, and the condition of the pipe. Use caution, as some
submersible pumps will discharge water too fast and may cause water
to backup into the yard or the house. A pump that operates at 700
gallons per hour is about the right size. Table 1 below will help
you determine the approximate time to drain your pool.
Table 1. Indicates the time it will take to drain your
pool depending on
pumping rate and amount of water you are removing.
IS POOL WATER SAFE FOR PLANTS?
Pool water can be safely
used to irrigate salt-tolerant plants. But, since it does contain
more salt and chlorine than tap water, you should use caution when
using pool water on certain areas of your landscape. Avoid spraying
pool water directly onto leaves or watering the same area
repeatedly. Injury symptoms to look for include yellowing or
browning of leaf edges, or of the entire leaf, and/or extensive leaf
drop. For best results, wait 3-7 days after treatments before
draining to allow chlorine to dissipate. The pH should be in the
range of 7-8. Drain the water slowly to avoid runoff and
over-saturation of the soil. See Table 2 for relative salt tolerance
levels of common landscape plants:
|Plants Sensitive to Salt:
Do Not Use Pool Water
|Moderately Sensitive to Salt:
Limited Use of Pool Water
|Salt Tolerant Plants:
Can Use Pool Water
Table 2. Shows the salt sensitivity of common landscape plants. This
list is adapted from
a publication provided by the University of Arizona Cooperative
Native to coastal areas, Natal Plum (left) is very salt
tolerant and pool water can be applied.
Plants like Bougainvillea
(left) are also very salt
tolerant and can be watered with pool backwash.
WHAT IF I NEED TO ACID WASH, REPLASTER OR HAVE OTHER
Since discharges from pool repairs can
include solid waste particles and high concentrations of chemicals,
wastewater discharges from these activities are not allowed to go to
either the City of Mesa storm sewer system or the City of Mesa
sanitary sewer system.
Generally, these types of services are initiated by the property
owner under contract or similar agreement with a pool equipment and
repair company. It is the responsibility of the property owner to
ensure that all pool repair wastewaters are managed by the repair
company in a manner consistent with City ordinances.
IS MY POOL LEAKING?
In our dry desert climate, the typical
swimming pool can evaporate its equivalent water volume in one year
- up to 25,000 gallons of water. Along with evaporation, you will
also have water lost to 'splash out' and as mentioned above, for the
backwash process. However, it is also estimated that up to 30
percent of all pools have a leak, wasting lots of water
Since half of the pools out there have a fill valve (automatic pool
refiller), leaks often go unnoticed, and problems are not only
occurring in aging pools but in new ones, too. Leaks may occur due
to a variety of reasons, like holes, tears, or cracks allowing the
water to leak undetected under the pool decking or the pool itself.
But more often leaks are a result of plumbing problems or improper
seals around fittings.
Water Saving Tips to Keep the Splash In Your Pool to learn how
to check for leaks and to see the typical amount of water lost each
month naturally due to evaporation, as well as easy tips to save
HOW WILL I BE CHARGED FOR REFILLING MY POOL?
for the water used to fill your pool is based on consumption,
just like the water used inside your home. It is billed per
thousand gallons based on the current City of Mesa rates.
If you fill
the pool between April and November, there will be no impact on
your monthly wastewater (sewer) charge since the wastewater
charge is calculated each April based on an average of the
previous winter's usage.
If you fill
the pool between December and March, remember that the monthly
wastewater (sewer) charge is based on an average of your three
lowest monthly winter water use readings between that four month
period. So, filling the pool during these months may impact your
monthly wastewater fee for the following year. You can contact
the Customer Service Call Center at (480) 644-2221 and request a
Wastewater Fee Adjustment Form.
This form would allow you to account for the higher usage so
that it will not be calculated into your winter water average
for that following year.
The City of
Mesa no longer rents fire hoses or hydrant wrenches for pool
filling. This practice was discontinued several years ago
In order to
judge the impact of filling your pool to your next water bill,
you can read the water meter before you start filling the pool
and read it again when the pool is filled. The difference
between these reads can be multiplied by the
current water rates to calculate the cost
of the water used. This may be helpful in budgeting for the cost
of the water used.
HOW DO I
FIND MORE INFORMATION?
If you're unsure about
draining your pool, or you'd like assistance, you may want to
contact a professionally-licensed pool service company or plumber.
The City of Mesa is a proud member of STORM.
REMEMBER, ONLY RAIN IN THE STORM DRAIN
Updated July 1, 2013