Environmental Engineering Reference
In-Depth Information
consider lengthy interruptions in water service as acceptable. A
decision to install temporary service lines or other alternative
water sources requires careful consideration of a number of fac-
tors including: site conditions, fire flow requirements, expected
duration of the service interruption, cold temperatures, backflow
prevention devices, internal plumbing, number of customers
affected, and the type of customer (e.g., hospitals, schools, or indi-
vidual residences).
Temporary pipelines are made of a variety of materials,
including steel, polyvinyl chloride (PVC), and high density poly-
ethylene (HDPE). The use of fire hoses or rubber hoses should be
avoided. Components must be certified to NSF Standard 61 and
approved for potable water service. Generally, installation fol-
lows the same procedures as for permanent pipelines.
Flush and disinfect all hydrants used as supply
Carefully select pipeline location and placement
Select appropriate pipeline material
Install pipeline, with ramps as necessary and buried
where required
Install backflow prevention device where required
Connect pipeline to hydrant
Fill line, chlorinate, flush, sample, and test for chlorine
residual and bacteria
Transfer customers to temporary service following satis-
factory test results
Remove temporary service
Ops
Tip
Store short, predisinfected coils of approved pipe so they
are ready for emergency use.
Disinfection procedures are the same as for permanent pipe-
lines (ANSI/AWWA C651). Temporary pipelines must be flushed
(usually at 2.5 ft/sec) to remove any dirt or debris. Chlorination is
conducted according to C651 and as described in the following
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