March
2,
2005
Matt
Gluckman
USEPA
Region
V
RE:
Corrosion/
Photo
processing
chemistry
Fox
River
Water
Reclamation
District
would
like
USEPA
to
review
the
possibility
of
implementing
Pretreatment
Standards
for
indirect
dischargers
in
the
photographic
point
source
category.
A
corrosion
study
initiated
by
FRWRD
to
identify
the
source
of
corrosion
experienced
at
one
of
our
pump
stations
(
pumps,
comminutor,
force
main)
identified
photochemistry
as
a
major
contributing
factor.
The
corrosion
was
of
permanently
wetted
surfaces,
so
it
was
not
the
typical
hydrogen
sulfide
corrosion
at
the
crown
of
gravity
sewers.
Also,
infrequent
pH
monitoring
at
the
pump
station
did
not
show
pH
far
from
neutral.
Continuous
pH
monitoring
at
the
large
photo
processor
discharging
to
the
pump
station
had
their
flow
at
pH
>
7.
The
photo
processor's
flow
represented
90%
of
the
influent
to
the
pump
station.

Engineering
Systems
Inc
(
ESI)
was
retained
by
FRWRD
to
investigate
the
corrosion
problems,
identify
the
source(
s),
and
recommend
solutions.
ESI's
report
concluded
that
the
force
main
and
equipment
at
the
pump
station
corroded
because
of
exposure
to
high
levels
of
ionic
sulfur
chemicals,
particularly
thiosulfate
and
sulfide
ions,
being
discharged
from
the
large
photo
processing
facility.
"
When
present
in
water
(
even
in
near
neutral
water),
reduced
sulfur
ions
(
i.
e.
thiosulfates,
sulfides,
&
sulfites)
form
iron
sulfides....
and
readily
exfoliate
from
the
surface
thus
greatly
increasing
the
corrosion
rate.
Also
high
sulfur
levels
in
wastewater
can
encourage
the
growth
of
Sulfur
Reducing
Bacteria,
making
conditions
favorable
for
deterioration
of
concrete."

We
could
provide
ESI's
full
report
to
EPA
upon
request.

Thank
you,
Fox
River
Water
Reclamation
District
Randy
Chapman,
Pretreatment
Coordinator
Rick
Manner,
District
Engineer
