UFC 3-280-04
17 DEC 2003
Table 6-1. Commonly Encountered O&M Problems
Description
Control Measures
Turbidity
Unacceptable levels of turbidity in efflu-
Pre-treat with chemicals or polymers, or
breakthrough
ent before terminal head loss is
both, upstream of the filter bed.
reached.
More frequent backwashing.
Reduce solids loading through pre-
filtration solids removal, such as
sedimentation.
Mudball
Masses of solids, dirt, and media, the
Auxiliary washing processes (e.g., air
formation
mudballs sink into the filter bed,
scour, surface wash) with, or followed
reducing the effectiveness of filtering
by, water wash
and backwash.
Buildup of grease
Oil or grease emulsifying within the
Air and surface wash usually help.
and oil
bed.
May be necessary to install washing
system using special solutions.
Pre-treat for oil and grease.
Carbonate
Carbonate buildup on media after lime
Acid rinse or, for small systems, replace
buildup
media.
Influent pH adjustment.
Cracks /
Develop when filter bed is not cleaned
Adequate backwash and scour.
contraction
properly.
Loss of media
Loss during backwashing or through
Correct placement, sizing of wash water
underdrain system.
troughs, and underdrain system.
Correct backwash flow or pressure.
Air binding
Gases coming out of solution in the
Backwash at terminal head loss no
water because of negative heads.
greater than the depth of submergence
of the top of the filter media or increase
submergence.
Gravel mounding
Support gravel disruption during
Overlay gravel support layer with layer of
backwash.
high density material, such as ilmenite or
garnet.
Correct backwash flow rate or pressure.
Excessive head
Filter element clogged without alarm
Change elements and check alarm for
loss
sounding.
malfunction.
Excessive
Filter element damaged.
Change element more frequently and look
turbidity without
for waste stream components that could
head loss
damage filter fabric.
Excessive filter
Filtration system improperly sized for
Increase the number of filter elements
element
waste stream.
operating in parallel.
changeout
If allowed by the application, increase the
cartridge removal rating so that fewer
solids are retained.
Influent pretreatment to reduce solids
loading.
Biofouling
The growth of a biologic mass, such as
Chemical pretreatment at the source or
algae, either within the waste stream or
within the treatment process using
the treatment process, that creates a
hydrogen peroxide or chlorination.
solids loading of a concentration and
Identify the factors contributing to bio-
character that cannot be effectively
mass growth (e.g., heat, excessive
filtered.
holding time, high organics in the waste
stream) and eliminate them.
6-5
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