SEPA Oasis Mobile Home Park Flushing Procedures

U.S. Environmental Protection Agency • Pacific Southwest Region • San Francisco, CA • May 2023

Residential Flushing Procedure Handout:

Residential Flushing Procedure

Oasis Mobile Home Park is conducting monthly flushing of their water distribution system to improve water quality. This
flushing usually takes about 3 days to complete for the entire park. As part of their effort, the park operator should be handing
out flyers to residents to notify them in advance of the flushing and to provide instructions for residents to flush their own
plumbing after the park operator finishes flushing in their area of the park. Flushing of your plumbing is extremely important
because there is a possibility that you may observe some negative impacts to the water quality in your home shortly after the
flushing of the park's distribution system. Possible changes to the water quality that you might observe include discoloration of
the water, an unpleasant odor or increased levels of arsenic. Flushing of the main lines may cause sediment or particle build-up
within the water lines to dislodge from the main lines that could end up in your home plumbing. The following steps have
been provided for you to help explain the proper way for you to thoroughly flush the plumbing in your home.

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Residents and end users should start
outside the home/building at the exte-
rior hose bib/faucet and open the hose
bib/faucet to the "full open" position.

Allow the exterior water line to run
for at least 2 minutes, or up to 10
minutes until the water runs clear. Be
sure to close the hose bib/faucet when
you are done. Beginning the flush
outside the home will target the service
lines first and help to lower the chance
of pulling sediment into the home's
interior plumbing.

Inside the home, remove any aerators from the kitchen
and bathroom faucets prior to beginning the flush.
Removing the aerators will allow any sediment to flow
freely and eliminate the chance of sediment getting
stuck in the aerator screen.

Most faucet aerators will come off by gripping the aera-
tor and turning it clockwise while looking down at the
sink. If the aerator is on too tight you may need a pair
of pliers. If you need to use pliers, cover the upper and
lower teeth with electrical tape so the aerator doesn't get
scratched. Some faucet aerators require a special key to
remove. If you are unable to remove your aerators and
need help, please contact Oasis staff at the emergency
phone number (909) 372 — 8438.

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Faucet Aerator

While the aerators are oft, inspect the screens for debris
or hard water buildup. Hold the aerator under running
water and use your finger to remove any debris. If
debris is stuck in the aerator screens, use a spare tooth-
brush to gently scrub away the debris. For hard water
buildup, soak the aerator in distilled white vinegar for
20-30min, then rinse the aerator under running water.

Open all COLD water taps
inside the home to the "full
open" position, including
kitchen, bathroom, and
shower faucets. Allow all inte-
rior COLD water taps to run
full open at the same time for
at least 2 minutes, or up to 10
minutes, until the water runs
clear. Close all COLD water
taps. Flushing cold water taps
before hot water taps will pre-
vent pulling sediment through
the hot water heater where it
could potentially get stuck.

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With the faucet aerators still removed,
open all HOT water taps to the "full
open" position, this includes kitchen,
bathroom, and shower faucets. Allow
all interior HOT water taps to run full
open for at least 2 minutes, or up to
10 minutes, until the water runs clear.
Close all HOT water taps. Flushing hot
water taps last will bring fresh water into
the hot water heater.

After flushing both cold and hot water taps,
reinstall the faucet aerators that were removed,
if you have them.


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FREQUENTLY ASKED QUESTIONS

Why is flushing necessary?

Flushing is necessary to address any arsenic and iron accumulation within the distribution system plumbing. The source
water used at Oasis MHP contains elevated levels of arsenic. Iron is added to the water during the treatment process to
help lower the arsenic levels. Improvements to the water treatment process are under way. The goal of these improvements
is to reduce the amount of iron and arsenic that accumulate in the distribution system plumbing. One sign of iron accu-
mulation is discoloration of the water. Water with high iron levels will appear orange or reddish brown. Flushing the water
distribution system is important to reduce the levels of iron and arsenic that may have accumulated in the water pipes and
plumbing system.

Why does my water look rusty or cloudy after flushing?

When a hydrant is opened, the water in the mainline flows out at a high velocity. This creates a scouring action in the
pipe and dislodges fine sediment particles that have accumulated in the pipe overtime. The fine sediment mixes with the
water, turning the water a cloudy or rusty brown color. Most of the sediment will be flushed out of the hydrants, but there
may be some residual sediment/particulate that makes its way into the residential plumbing. In addition to a temporary
discoloration of the water, you may also notice a change in taste and odor. To mitigate these water quality changes, it is
important that you flush the plumbing in your home by following the instructions on the Residential Flushing Procedure
Handout.

How can I reduce water quality impacts in my home?

*	Avoid using water while the mainlines are being flushed, including turning on the dishwasher, washing machine, and
any faucets in the kitchen, bathroom, or outside the home.

•	Thoroughly flush your home's plumbing by following the Residential Flushing Procedure Handout.

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