BRIEFING
MEMO
GENERAL
MITCHELL
INTERNATIONAL
AIRPORT
MILWAUKEE,
WISCONSIN
WPDES
Permit
No.
WI­
0046477­
2
October
25,
2000
GENERAL
DESCRIPTION:

General
Mitchell
International
Airport
is
approximately
2,200
acres
in
size
and
is
served
by
a
county
owned
storm
sewer
system
consisting
of
about
25
miles
of
separate
storm
sewers
and
5
miles
of
ditch.
Runoff
from
rain
and
snow
melt
at
the
airport
can
contain
glycol
and
other
chemicals
used
to
deice
or
anti­
ice
aircraft
and
runways,
and
other
pollutants
from
industrial
activities
at
the
airport.
Deicing
and
anti­
icing
activities
are
mandatory
requirements
of
the
Federal
Aviation
Administration
to
ensure
adequate
safety
for
airport
operations.
Contaminated
runoff
problems
are
seasonal
during
the
periods
of
deicing
or
anti­
icing
in
the
winter.
At
other
times,
the
runoff
from
the
airport
is
typical
of
urban
storm
water
runoff.

The
glycol
is
a
problem
because
of
its
high
biochemical
oxygen
demand
(
500,000
to
1,000,000
mg/
L
BOD5),
which
depletes
the
dissolved
oxygen
in
the
receiving
water,
and
additives
in
the
glycol
are
toxic
to
aquatic
life.
Glycol
usage
during
a
deicing
season
ranges
between
150,000
to
250,000
gallons
per
year
(
undiluted)
depending
on
weather
conditions.
Both
ethylene
glycol
and
propylene
glycol
deicing
and
anti­
icing
fluids
are
used,
with
a
trend
toward
more
propylene
glycol.
Five
years
ago
ethylene
glycol
was
used
more,
because
it
worked
better
and
was
less
expensive.
Now
less
than
10%
of
all
glycol
used
is
ethylene
glycol.
This
reduction
is
a
combined
result
of
ethylene
glycol
being
listed
as
a
hazardous
material,
and
a
preference
for
propylene
glycol
for
safety
and
its
greater
value
if
recycled.

There
are
two
categories
of
glycol
products
used,
depending
on
whether
they
remove
ice
and
snow
or
if
they
prevent
it
from
accumulating.
"
Type
I"
deicing
fluids
are
used
to
remove
ice
and
snow
on
the
aircraft.
"
Type
II
and
IV"
fluids
anti­
ice
to
prevent
any
accumulation
of
ice
or
snow
on
clean
aircraft
surfaces.
Anti­
icing
fluids
are
thicker
than
type
I
to
adhere
to
the
aircraft
and
provide
increased
holdover
time
prior
to
takeoff.
Advances
in
the
technology
of
deicing
and
anti­
icing
aircraft,
including
selection
of
freeze
point
depressants
(
glycol
or
some
other
chemical)
and
application
methods,
will
ultimately
be
the
keys
to
managing
the
environmental
problems
associated
with
airport
runoff.

Airport
runoff
enters
the
storm
sewer
system
and
discharges
from
three
major
outfalls
to
receiving
waters.
Two
outfalls
drain
into
the
Kinnickinnic
River
via
Wilson
Park
Creek,
and
one
drains
into
a
tributary
to
Oak
Creek.
Pollutants
of
concern
in
the
storm
water
include
deicing
and
anti­
icing
chemicals,
petroleum
products,
suspended
solids,
metals,
nutrients,
and
traces
of
toxic
materials.
Milwaukee
County
has
conducted
an
extensive
site
investigation
to
provide
information
on
the
airport's
separate
storm
sewer
system
and
characterized
storm
water
runoff
quality.
A
monitoring
program
of
visual
inspections
and
chemical
analysis
is
used
to
determine
storm
water
runoff
quality
to
evaluate
storm
water
best
management
practices,
and
to
provide
a
continuing
database
for
water
quality
changes.
Monitoring
locations
consist
of
inflows
to
the
airport's
storm
sewer
system,
the
down
stream
receiving
water,
oil
and
water
separators,
and
the
three
major
outfalls
from
the
airport.

This
permit
will
regulate
the
discharges
from
the
separate
storm
sewer
system
serving
the
airport.
Pollution
prevention
efforts
are
emphasized
and
preferred
over
treatment
of
runoff
at
the
airport,
because
treatment
is
difficult.
Major
components
of
the
permit
include
the
following:
a
storm
water
pollution
prevention
plan
to
reduce
pollutant
sources,
monitoring
of
storm
water
discharges,
discharge
performance
requirements
for
reductions
in
pollutant
loading
through
implementation
of
best
management
practices,
and
an
annual
report
to
summarize
and
assess
compliance
with
the
permit.
As
part
of
their
storm
water
pollution
prevention
plan
to
minimize
impacts
to
the
receiving
water,
the
airport
is
capturing
glycol
to
the
maximum
extent
practicable,
and
using
conservation
efforts
to
reduce
the
amount
of
glycol
used.
Page
2
SPECIFIC
PERMIT
CONDITIONS:

This
section
of
the
briefing
memo
describes
the
proposed
permit
requirements,
changes
from
the
previous
permit,
and
the
rationale
for
the
specific
conditions.
The
permit
regulates
the
discharge
in
accordance
with
ch.
283,
Wis.
Stats.
and
ch.
NR
216,
Wis.
Adm.
Code
that
regulates
storm
water
discharges.
An
individual
permit
instead
of
a
general
permit
regulates
the
storm
water
in
accordance
with
s.
216.25(
3),
Wis.
Adm.
Code,
because
deicing
and
anti­
icing
can
be
a
significant
source
of
pollutants.

The
first
permit
issued
March
14,
1996
and
expires
December
31,
2000.
The
permit
was
modified
April
2,
1997,
to
extend
interim
compliance
schedule
due
date
for
deicing
and
anti­
icing
facilities
plan.
Additional
time
was
needed
for
the
Kinnickinnic
River
study,
negotiations
with
MMSD,
and
selection
of
the
facility
plan
alternative.
A
second
modification
November
26,
1997,
the
approved
to
new
alternative
monitoring
locations
that
replaced
two
locations
in
the
permit
that
were
found
to
be
inaccessible
because
they
were
too
close
to
runways.

1.
Tenant
Coverage
The
airport
permit
covers
20
co­
permittees
under
one
permit.
This
allows
DNR
to
efficiently
regulate
Milwaukee
County,
the
owner,
and
19
airport
tenants,
who
are
the
operators,
all
together
instead
of
through
separate
permits.
A
tenant
conducting
industrial
activity
that
may
contaminate
storm
water
runoff
must
be
permitted
if
they
meet
two
criteria:
(
1)
is
in
the
air
transportation
business,
and
(
2)
is
involved
in
maintenance,
fueling,
cleaning,
or
deicing.
All
the
tenants
needing
permitting
are
covered
under
this
permit.
Revisions
to
the
airport
co­
permittee
list,
which
identifies
tenants
covered
under
this
permit,
may
be
made
by
the
Department
to
reflect
changes
in
tenant
status
during
the
term
of
the
permit.

2.
Applicability
This
permit
applies
to
General
Mitchell
International
Airport
within
the
jurisdiction
of
Milwaukee
County,
and
includes
airport
tenants
as
co­
permittees.
Storm
water
runoff,
and
flows
contributed
by
process
and
non­
process
wastewater
into
the
airport's
separate
storm
sewer
system,
are
regulated
point
source
discharges
under
this
permit.
Except
as
permitted
or
authorized
by
the
permit,
discharges
from
the
airport's
separate
storm
sewer
system
may
not
contain
pollutants
which
would
cause
a
violation
of
water
quality
standards.
The
airport's
storm
water
pollution
prevention
plan
must
limit
the
discharge
of
pollutants
to
the
maximum
extent
practicable.
Implementation
of
the
best
management
practices
described
in
the
storm
water
pollution
prevention
plan
is
a
step
in
addressing
compliance
with
water
quality
standards.

There
are
individual
and
joint
responsibilities
between
Milwaukee
County
and
the
airport
tenants
who
become
co­
permittees.
The
airport's
storm
sewer
system
also
receives
inflows
from
off
site,
including
drainage
from
Cudahy,
Oak
Creek,
Milwaukee,
the
Wisconsin
Air
National
Guard,
and
the
US
Air
Force
Reserve.
At
times
off
site
inflows
contribute
pollutants
to
the
storm
sewer
system,
which
are
apparent
when
the
airport
isn't
deicing.
And
discharges
from
non­
permitted
airport
tenants
may
also
contribute
pollutants.
The
airport
is
not
responsible
for
the
input
of
pollutants
from
off
site
or
from
tenants
who
are
not
co­
permittees.
These
other
pollutant
sources
will
be
addressed
as
the
storm
water
program
progresses.

3.
Authorized
Discharges
The
permit
regulates
certain
discharges
of
storm
water
runoff
from
the
airport
upstream
from
the
3
major
outfalls.
It
also
will
regulate
wastewater
discharges
from
deicing
and
anti­
icing
activities,
and
oil
and
water
separators.
Non­
storm
water
discharges
contributing
pollutants
are
prohibited.
To
screen
for
illicit
connections
to
the
storm
sewer
system,
an
evaluation
of
non­
storm
water
discharges
was
completed
and
will
be
repeated
at
least
every
5
years.
Page
3
Excluded
from
coverage
under
this
permit,
because
they
aren't
within
the
Department's
authority
to
regulate
are
areas
of
the
airport
that
are
segregated
from
the
industrial
activities.
Not
covered
are
office
buildings,
parking
lots,
and
undeveloped
areas.
Also
excluded
are
areas
off
site
or
upstream
of
the
airport,
and
tenants
who
do
not
meet
the
permitting
criteria.
Innocuous
non­
storm
water
discharges
may
also
enter
the
storm
sewer
system
without
regulation.

4.
Storm
Water
Pollution
Prevention
Plan
Development
and
implementation
of
a
storm
water
pollution
prevention
plan
was
the
major
component
of
the
first
permit.
Best
management
practices
were
evaluated
and
will
be
implemented
to
limit
to
the
maximum
extent
practicable
the
discharge
of
pollutants
from
the
separate
storm
sewer
system.
Cost
effective
pollution
prevention
practices
are
emphasized.
Source
areas
of
pollution
were
evaluated
for
the
reduction
of
pollutants
entering
storm
water.
The
airport
submitted
their
storm
water
pollution
prevention
plan
dated
December
1994,
and
a
best
management
practices
manual
dated
November
4,
1994.
The
plan
was
updated
by
June
30,
1997,
to
include
a
monitoring
program
and
a
facilities
plan
for
controlling
runoff
contaminated
with
glycol
used
to
deice
or
anti­
ice
aircraft.
The
facilities
plan
for
glycol
management
was
submitted
November
6,
1997,
and
the
selected
alternative
was
approved
November
26,
1997.
The
storm
water
pollution
prevention
plan
was
amended
February
25,
1998,
to
include
the
glycol
management
controls.
The
airport
has
proceeded
with
the
implementation
of
glycol
management
controls
as
required
by
the
first
permit's
compliance
schedule.

Conservation
practices
by
airlines
have
reduced
the
amount
of
glycol
used,
and
the
relative
amount
that's
collectable.
Increased
use
of
Type
II
and
IV
glycol
reduces
the
overall
volume
of
glycol
because
it's
more
effective
by
providing
longer
protection,
and
is
less
likely
to
runoff.
Optimized
blending
of
glycol
mixtures
to
use
less
than
the
normal
50%
when
temperatures
are
milder
reduces
glycol
usage.
Also,
improved
methods
of
deicing
with
new
hybrid
deicing
equipment
that's
more
efficient
by
utilizing
forced
air,
high
pressure,
and
low
flow
glycol
spray,
reduced
the
amount
of
glycol
used
by
Delta
Airlines
by
70%
or
more.
In
addition,
the
use
of
urea
for
runway
deicing
was
discontinued
and
replaced
with
potassium
acetate
to
eliminate
the
discharge
of
ammonia.

A
pilot
glycol
recovery
vehicle
(
GRV)
program
was
conducted
during
the
1998­
1999
deicing
season.
About
15%
of
the
glycol
was
collected,
which
was
much
below
the
goal
of
42.5%
(
see
section
7
on
surface
water
requirements).
The
apparently
poor
results
were
attributed
to
a
number
of
operational
problems
that
had
to
be
worked
out,
and
because
the
pilot
test
was
in
a
limited
focus
area
only
and
the
test
didn't
run
the
entire
deicing
season.
Improvements
in
the
glycol
collection
were
realized
in
the
1999­
2000
deicing
season
when
a
full
scale
program
was
initiated
based
on
what
was
learned
from
the
pilot.
The
capture
rate
was
still
only
about
21%
overall,
but
was
37.6%
in
the
focused
area
where
71%
of
the
glycol
was
applied.

The
glycol
management
controls
during
1999­
2000
consisted
of
the
following
components:
1.
Two
glycol
recovery
vehicles
(
GRV),
one
large
Vactor
GRV
(
1600
gallon
capacity)
and
one
small
Crosswinds
GRV
(
350
gallon
capacity)
collecting
glycol
in
the
terminal
ramp
areas.
2.
Storm
sewer
balloons
at
eight
locations
providing
a
"
block
and
pump
system"
that
diverts
glycol
contaminated
runoff
into
storm
sewers
for
temporary
storage
until
it
can
be
pumped
out.
Storm
sewer
inserts
at
two
locations
prevent
runoff
from
entering
the
storm
sewer,
and
pond
glycol
contaminated
runoff
on
the
surface
for
the
GRV
to
vacuum
up.
3.
A
remote
deicing
pad
was
constructed
in
1998
just
east
of
the
cargo
area,
which
serves
Skyway
Airlines
and
others
smaller
commuter
aircraft.
Runoff
from
deicing
collects
in
a
pool
at
a
corner
of
the
pad
and
drains
into
a
collection
sump.
A
level
activated
pump
transfers
the
collected
runoff
to
a
frac­
tank
for
storage.
Clean
runoff
can
be
diverted
to
a
storm
sewer
catch
basin.
4.
Eight
frac­
tanks,
each
with
a
capacity
of
21,000,
are
placed
at
four
locations
to
store
the
runoff
collected
by
the
GRVs,
block
and
pump
system,
and
the
remote
deicing
pad.
If
more
storage
is
necessary,
additional
frac
tanks
can
be
obtained
within
24
hours.
Page
4
A
digital
refractometer
is
used
to
determine
the
glycol
concentration
so
the
wastewater
can
disposed
of
by
the
appropriate
method.
Runoff
with
"
high
concentrations"
of
glycol
averaging
10%
to
15%,
can
be
recycled
by
Signature
Flight
Support
in
Denver,
with
a
credit
of
about
$
1
per
gallon
of
reclaimed
glycol.
Runoff
with
glycol
concentrations
less
than
5%
are
discharged
into
a
Milwaukee
Metropolitan
Sewerage
District
(
MMSD)
sanitary
sewer.
Runoff
with
concentrations
between
5%
and
10%
is
trucked
to
anaerobic
sludge
digesters
at
MMSD's
South
Shore
treatment
plant,
the
City
of
South
Milwaukee,
or
the
City
of
Brookfield.
The
airport
continues
to
negotiate
with
MMSD
for
fair
disposal
costs
and
a
long
term
contract
for
treatment
of
low
and
medium
concentration
runoff.

For
the
2000­
2001
deicing
season,
in
order
to
improve
on
the
capture
rate,
a
tow­
behind
glycol
collection
unit
with
a
1000
gallon
capacity
was
purchased
to
replace
the
smaller
Crosswinds
GRV.
This
unit
will
be
used
with
the
Vactor
GRV
to
increase
the
collection
capability
and
to
expand
the
glycol
collection
area.
The
tow
behind
(
by
a
tractor)
vacuum
unit
operates
slightly
different
than
the
Vactor
GRV,
and
may
provide
flexibility
because
it
can
deal
with
snow
covered
conditions
better.
Also,
one
additional
sewer
balloon
and
one
additional
sewer
insert
will
be
installed,
increasing
to
90%
the
total
terminal
ramp
area
that
is
blocked
off.
And
another
pump
truck
will
be
needed
for
handling
the
additional
glycol
captured.
To
determine
if
additional
efforts
to
collect
glycol
in
the
cargo
area
(
which
represents
10%
of
glycol
usage)
are
possible,
a
pilot
study
will
be
conducted
using
a
temporary
berm
to
collect
runoff
in
a
low
spot
that
can
be
pumped
out
before
it
reaches
a
storm
sewer
that
discharges
to
Outfall
001.

The
permit
requires
continued
implementation
of
the
storm
water
pollution
plan
and
glycol
management
controls
to
comply
with
the
capture
goal
described
in
the
discharge
requirements.
The
storm
water
pollution
prevention
plan
is
an
on
going
process,
which
includes
monitoring
to
evaluate
the
plan's
effectiveness,
and
amendments
to
the
plan
as
necessary
to
protect
the
waters
of
the
state.

5.
Inflow
and
Receiving
Water
Requirements
Visual
inspections
and
chemical
analysis
are
required
at
Sampling
Point
701
that
represents
inflow
to
the
airport
from
Bailey's
Pond,
and
at
Sampling
Point
601
that
represents
a
downstream
location
in
Wilson
Park
Creek.
Quarterly
visual
inspections
look
for
any
obvious
runoff
problems.
The
chemical
sampling
requires
an
analysis
of
13
storm
water
parameters.
The
parameter
lists
includes
parameters
of
concern
based
on
previous
monitoring
results,
and
water
quality
indicator
parameters.
They
include:
ethylene
glycol,
propylene
glycol,
BOD5,
COD,
TSS,
TSS,
ammonia,
TKN,
DO,
pH,
hardness,
copper,
lead,
and
zinc.
Chemical
sampling
is
required
annually,
but
with
three
samples
required
at
Wilson
Park
Creek
for
glycol,
BOD5,
COD,
TSS,
DO,
and
pH.
This
additional
sampling
is
to
collect
more
data
related
to
glycol
recovery
and
the
impact
on
the
receiving
water.
The
monitoring
for
metals,
hardness,
ammonia,
and
TKN
are
limited
to
just
the
first
and
last
year
of
the
permit
because
they
aren't
at
concentrations
of
concern,
but
some
sampling
is
required
to
maintain
some
baseline
data.
Because
urea
was
eliminated
as
a
deicing
chemical,
nitrogen
compounds
should
no
longer
be
a
concern,
and
the
metal
concentrations
are
typical
of
storm
water
runoff.

The
airport
also
contracts
with
the
USGS
for
additional
storm
water
monitoring
beyond
what
the
WPDES
permit
requires.
The
USGS
is
doing
a
detailed
study
of
the
Kinnickinnic
River
for
the
purpose
of
evaluating
the
impact
of
the
airport's
runoff.
Numerous
samples
for
chemical
analysis
are
collected
from
several
locations,
and
toxicity
tests
are
also
being
done.
In
addition,
the
USGS
is
conducting
a
study
of
snow
piles
that
monitors
the
glycol
contained
in
the
snow
that's
plowed.
The
snow
melt
from
the
pile
ends
up
in
both
the
storm
sewers,
and
absorbs
into
the
soil.
How
significant
an
impact
from
this
snow
melt
will
be
evaluated.

6.
Oil
and
Water
Separator
Requirements
There
are
4
existing
oil
and
water
separators
at
the
airport,
serving
as
treatment
control
measures
at
fueling
or
fuel
storage
areas.
Sample
Points
101
(
has
two
separators),
102,
and
103
monitor
the
discharge
from
the
oil
and
water
separator
discharges
to
the
storm
sewer.
Discharges
from
the
oil
and
water
Page
5
separators
are
an
authorized
non­
storm
water
discharge,
and
are
regulated
under
this
section
of
the
permit.
Special
conditions
for
the
operation,
effluent
limitations
based
on
categorical
treatment
standards,
and
monitoring
requirements
reflect
those
from
the
oil
and
water
separator
general
permit.
Another
oil
and
water
separator
is
located
at
the
Equilon
fuel
pipeline
terminal
on
College
Avenue,
but
is
regulated
by
a
general
permit
issued
to
Equilon
so
it's
not
included
under
this
permit.

7.
Surface
Water
Requirements
Visual
inspections
and
chemical
analysis
are
required
at
the
outfalls
from
the
airport.
They
consist
of
Outfalls
001
and
007
that
discharge
to
Wilson
Park
Creek,
and
Outfall
003
that
discharges
to
Oak
Creek.
The
chemical
monitoring
is
similar
to
the
inflow
and
downstream
sampling
points,
but
with
the
addition
of
an
estimated
flow
to
determine
pollutant
loadings,
and
oil
and
grease.
Annual
monitoring
is
required
at
Outfall
001
and
007,
but
with
three
samples
required
at
Outfall
007
for
ethylene
glycol,
propylene
glycol,
BOD5,
COD,
TSS,
DO,
and
pH.
Outfall
007
also
has
monitoring
for
hardness,
copper,
lead,
and
zinc
to
continue
this
baseline
monitoring.
For
the
same
reason
as
the
inflow
and
receiving
water
sampling
points,
the
monitoring
for
metals,
hardness,
ammonia,
and
TKN
are
limited
to
just
the
first
and
last
year
of
the
permit.
Because
Outfall
003
showed
no
significant
impact
from
runoff,
only
flow
estimates
and
visual
inspections
are
required
here.

General
narrative
type
discharge
limitations
are
used
to
protect
water
quality.
For
determining
compliance
with
implementation
of
the
pollution
prevention
plan
efforts,
especially
deicing
and
anti­
icing
management
controls,
the
reduction
in
glycol
discharged
is
evaluated.
Technology
based
cost
effective
best
management
practices
for
controlling
storm
water
discharges,
described
in
the
airport's
storm
water
pollution
prevention
plan,
are
the
means
for
addressing
water
quality
standards.

The
first
permit
contained
a
goal
to
capture
85%
of
half
the
glycol
that's
applied
for
deicing
and
antiicing
or
42.5%
of
the
total
glycol
applied.
Half
the
glycol
applied
is
considered
fugitive
because
it's
uncollectable.
This
would
include
the
glycol
that
is
sheared
off
aircraft
upon
takeoff,
runs
off
into
areas
where
it
can't
easily
be
collected,
or
volatilizes.
The
50%
fugitive
percentage
is
believed
to
be
fairly
accurate
based
on
data
from
several
airports.
In
the
permit
reissuance
this
fixed
percentage
goal
of
42.5%
is
being
replaced
with
a
formula
that
takes
into
account
conservation
efforts
and
the
use
of
type
IV
glycol
that
has
a
lower
capture
rate
estimated
at
12.75%.
This
is
necessary
because
as
less
glycol
is
used
through
conservation
efforts
there's
less
collectable
glycol.
The
annual
glycol
capture
goal
must
be
recalculated
each
year.
The
capture
goal
will
now
be
less
than
42.5%,
but
due
to
conservation
efforts
less
glycol
will
be
released
into
the
environment.
Capturing
85%
of
the
collectable
glycol
(
other
than
type
IV)
remains
the
same.

Specific
numeric
effluent
limitations
aren't
included
in
the
permit.
Chapters
NR
102
through
NR
105,
Wis.
Adm.
Codes,
which
contain
the
water
quality
standards,
currently
aren't
implementable
for
storm
water
because
these
administrative
codes
don't
contain
procedures
to
address
the
intermittent
nature
of
storm
water
discharges.
EPA
hasn't
proposed
any
effluent
limitation
guidelines
for
runoff
from
airports,
and
has
no
plans
to
do
so.
The
permit
will
continue
to
regulate
airport
discharges
by
way
of
best
management
practices.

8.
Schedules
of
Compliance
This
section
lists
required
permit
activities,
with
references
to
the
permit
sections
that
contains
the
requirement,
and
shows
the
due
date.
Requirements
are
included
for
a
comprehensive
annual
site
inspection
to
verify
activities
that
impact
storm
water,
an
annual
report
summarizing
permit
activities,
a
follow­
up
response
for
failure
to
comply
with
the
glycol
capture
goal,
and
need
for
permanent
infrastructure
for
deicing
and
anti­
icing
controls.

The
annual
report,
due
each
September,
serves
to
demonstrate
permit
compliance
and
provides
the
Department
with
information
to
keep
informed
of
airport
activities.
The
monitoring
data
summary
in
the
Page
6
report
serves
in
place
of
monthly
discharge
monitoring
report
forms.
The
annual
report
includes
the
following:

 
Status
of
storm
water
pollution
prevention
plan
implementation
 
An
updated
storm
sewer
system
map
reflecting
any
note
worthy
changes
 
A
summary
assessing
the
effectiveness
of
best
management
practices
 
Amendments
to
the
storm
water
pollution
prevention
plan
 
A
summary
of
the
monitoring
data
 
A
summary
of
the
estimated
reduction
in
glycol
discharged
 
Identification
of
any
receiving
water
quality
changes
 
Expenditures
for
the
past
year
and
next
year's
budget
If
the
glycol
capture
goal
isn't
attained,
management
practices
are
required
to
be
amended
as
necessary
to
meet
the
goal
during
the
next
deicing
season.
The
airport
must
submit
an
amendment
to
the
storm
water
pollution
prevention
plan
to
address
whatever
additional
efforts
or
changes
are
proposed
to
comply
with
the
glycol
capture
goal.

Implementation
of
the
glycol
management
controls
has
progressed
through
a
pilot
stage,
but
continues
to
use
some
temporary
equipment.
Due
to
emerging
technologies
and
time
needed
to
learn
the
best
glycol
controls
for
the
airport,
the
use
of
temporary
storage
tanks,
leased
GRVs,
and
phased
implementation
is
acceptable.
This
also
provides
the
airport
with
the
necessary
operational
flexibility.
Infrastructure
changes
from
airport
expansion
may
affect
future
glycol
management
controls.
The
airport's
plan
is
to
wait
until
the
expansion
plans
are
complete
before
proceeding
with
permanent
glycol
control
facilities
to
avoid
rework.
However,
eventually
permanent
equipment
will
need
to
replace
the
interim
temporary
measures.
Any
permanent
glycol
management
controls
will
be
addressed
in
the
next
permit
issuance.

9.
Standard
Requirements
The
relevant
standard
requirements
typical
to
all
WPDES
permits
are
provided.
These
include
requirements
for
reporting
and
monitoring,
operating,
and
surface
water
discharges.
Any
standard
requirements
not
applicable
to
the
permit
were
deleted.

10.
Summary
of
Reports
Due
The
airport
must
submit
to
the
Bureau
of
Wastewater
Management
and
the
Southeast
District
Office
reports
required
in
the
permit.
These
consist
of
the
annual
report,
and
any
reports
to
comply
with
permit
schedules
or
non­
compliance.

COMPLIANCE
REVIEW:

The
airport
is
in
substantial
compliance
with
the
requirements
contained
in
the
first
permit.
Excellent
progress
was
made
with
the
identification
of
storm
water
runoff
problems
and
implementation
of
controls
to
minimize
the
release
of
glycol
that
contaminants
runoff
and
enters
the
storm
sewer
system.
The
following
table
summarizes
glycol
usage
per
deicing
seasons:

Deicing
Season
Gallons
of
Glycol
Pounds
of
BOD5
1996
­
1997
265,452
720,038
1997
­
1998
211,675
574,168
1998
­
1999
161,457
437,952
1999
­
2000
223,405
460,549
The
estimated
BOD5
assumes
7.75
pounds
of
BOD5
per
gallon
of
glycol
with
35%
of
the
glycol
running
off
into
the
storm
sewer
system.
Some
of
the
variability
in
the
annual
glycol
usage
is
due
to
weather
Page
7
conditions,
but
deicer
and
anti­
icing
management
practices
and
conservation
efforts
have
generally
reduced
the
amount
of
glycol
used.
Less
than
the
42.5%
glycol
capture
goal
has
been
realized,
but
the
airport
is
responding
with
improvements
to
glycol
management
controls.
Errors
in
measuring
the
glycol
are
also
known
to
be
a
problem
in
accurately
tracking
compliance,
which
will
be
addressed
with
better
instrumentation
to
measure
the
glycol
concentrations.
And
a
new
formula
to
determine
the
glycol
capture
goal
will
better
reflect
the
maximum
collection
potential.

The
oil
and
water
separator
discharge
limits
have
occasionally
been
exceeded
for
oil
and
grease,
and
total
suspended
solids.
In
1999­
2000
five
violations
occurred.
In
response,
better
operation
and
maintenance
has
corrected
the
problem
as
evident
by
improved
effluent
quality
in
retests
after
servicing
and
clean
out.

There
were
groundwater
remediation
projects
at
the
airport
for
petroleum
contaminated
soil
or
groundwater.
The
remediation
projects
discharged
treated
contaminated
groundwater
into
the
separate
storm
sewer
system
as
an
authorized
non­
storm
water
discharge
regulated
under
the
first
permit.
Plans
and
specifications
for
the
groundwater
remediation
system
were
approved
June
30,
1997.
Remediation
sites
with
contaminated
groundwater
included
the
old
fuel
farm,
hydrant
fuel
farm,
and
UNOCAL
area.
There
were
problems
with
high
BOD5
concentrations
in
the
treated
groundwater,
which
was
attributed
to
glycol
that
wasn't
removed
in
the
activated
carbon
system.
The
pump
and
treat
groundwater
remediation
is
completed
and
the
treatment
systems
were
shut
down
May
11,
2000.
The
reissued
permit
deletes
this
component
of
the
first
permit.
Some
groundwater
monitoring
continues
in
these
areas.

RECOMMENDATION:

I
am
recommending
the
permit
be
reissued
in
accordance
with
the
specific
conditions
outlined
in
this
memo.
The
permit's
primary
purpose
is
to
reduce
to
the
maximum
extent
practicable,
the
runoff
of
glycol
from
aircraft
deicing
and
anti­
icing
to
prevent
the
contamination
of
storm
water
from
the
airport
that
discharges
to
waters
of
the
state.
Use
of
best
management
practices
and
a
glycol
capture
goal
is
the
permit's
means
to
comply
with
water
quality
standards.
The
permit
does
not
contain
water
quality
based
effluent
limits
or
whole
effluent
toxicity
testing
(
some
is
done
voluntarily).

Prepared
by:

Paul
W.
Luebke,
PH
Wastewater
Permits
and
Pretreatment
Section
Bureau
of
Watershed
Management
