Alaska Department of Environmental Conservation
Division of Environmental Health
Drinking Water Program
Response Flowchart for Loss of Pressure to a PWS Distribution System
The distribution system
below 20 psi.
Notify the local ADEC DW
Program Office immediately.
Did the distribution line
yes remain full of water and
have some measurable
Can the distribution lines Disinfect appropriately to
be disinfected to AWWA Yes
AWWA Standard C651.99
Have the distribution Flush at least two volumes
No Is the system No continue until the water is
lines been adequately chlorinated?
flushed? visually free of sediment, and
water is clear.
Flush until the chlorine residual reaches normal
operating levels with a minimum of twice the volume of
disinfection solution flushed through the affected area.
If the water is not visually free of sediment, continue
flushing until the water clears.
Collect bacteriological samples from the affected portion of
the distribution system .
Notify the local ADEC DW Program
Office immediately. Additional
Are all bacteriological No
measures including a Boil Water
Notice to the affected area may be
No Further Action
Pressure Loss Flow Chart 1 of 1 Version: 02-02-05