Environmental Engineering Reference
In-Depth Information
TAble 5.1
Troubleshooting Water Quality Problems in Storage/Distribution Systems
Problem
Possible Cause
Potential Solution
Taste and odor
High chlorine residual
Use breakpoint chlorination or lower
chlorine dosage
Biological (algae) growth or
microorganisms
Chlorinate
Dead end in main or tank
Flushing, eliminate dead end
Turbidity
Silt or clay in suspension,
calcium carbonate,
aluminum hydrate (alum),
precipitated iron, oxide,
microscopic floc carryover
Flushing of mains, proper operation of
water treatment plant processes
Color
Decay of vegetable matter
Chlorination
Microscopic organisms
(regrowth in tank)
Chlorination
Coliform present
Contaminated distribution
system
Locate and remove source
Cross-connection
Install backflow-prevention or air-gap
devices, flush, and temporarily
increase chlorine dosage
Negative pressure in main
Repair main, increase chlorine feed rate,
flush system and resample for coliform
analysis, adjust water level in tank to
maintain 20 psi to all connections
under all conditions of flow
No or improper disinfection
of new or repaired wells,
reservoirs, or mains
Use proper disinfection procedures
Water Quality Problems in Storage and Distribution Systems
The potable water practitioner may be called upon to troubleshoot water
quality problems while water is in storage facilities and distribution sys-
tems. Typical water quality problems that might be encountered include
taste and odor, t u r b i d it y, color, and presence of coliforms; see
Table 5.1
for
the types of problems commonly encountered, their possible causes, and
potential solutions.
Inspection of Storage Facilities
Drinking water practitioners must incorporate an annual inspection pro-
tocol for storage facilities, to verify the physical condition of the tank and
to verify that the tank is maintained in sanitary condition. Recommended
items to be inspected include the following:
