Document ID: EPA-HQ-OW-2003-0074-1315
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2004-09-02T04:00Z

FACT
SHEET
DANE
COUNTY
REGIONAL
AIRPORT
Madison,
Wisconsin
WPDES
Permit
No.
WI­
0048747­
02
October
3,
2001
GENERAL
DESCRIPTION:

Dane
County
Regional
Airport
is
2,150
acres
in
size
and
is
served
by
a
storm
sewer
system
consisting
of
about
14
miles
of
separate
storm
sewers,
of
which
25%
are
perforated
to
serve
as
an
underdrain.
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.
The
glycol
is
a
problem
because
of
its
high
biochemical
oxygen
demand,
which
depletes
the
dissolved
oxygen
in
the
receiving
water,
and
aquatic
toxicity.
Estimated
glycol
usage
averages
50,000
gallons
per
year
(
undiluted).
The
trend
in
the
kind
of
glycol
has
shifted
toward
more
propylene
glycol
since
the
last
permit,
with
usage
during
the
2000
­
2001
deicing
season
consisting
of
87%
propylene
glycol
and
13%
ethylene
glycol.
The
amount
of
glycol
used
varies
depending
on
winter
weather
conditions.
The
problem
is
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.

Airport
runoff
enters
the
storm
sewer
system
and
discharges
from
31
outfalls
into
Starkweather
Creek,
which
drains
into
the
Yahara­
Monona
watershed.
Pollutants
of
concern
in
the
storm
water
include
deicing
and
anti­
icing
chemicals,
petroleum
products,
suspended
solids,
and
traces
of
toxic
materials.
Metals
and
nutrients
have
not
been
found
as
a
problem
in
monitoring
data.
Dane
County
previously
conducted
a
site
investigation
that
provided
information
on
the
airport's
separate
storm
sewer
system
and
characterized
storm
water
runoff
quality.
A
storm
water
retention
pond
was
constructed
in
1991
to
prevent
the
majority
of
glycol
from
entering
Starkweather
Creek.
The
glycol
contaminated
runoff
is
captured
during
the
deicing
season
in
the
glycol
retention
pond,
which
provides
storage
and
treatment.
The
pond
effluent
is
either
discharged
into
a
sanitary
sewer,
or
if
the
pond
water
quality
meets
effluent
limitations
a
discharge
to
Starkweather
Creek
is
allowable.

This
permit
will
regulate
the
discharge
from
the
glycol
retention
pond
and
the
separate
storm
sewer
system
serving
the
airport.
Pollution
prevention
efforts
are
emphasized.
Major
components
of
the
permit
include
the
following:
a
storm
water
pollution
prevention
plan
to
reduce
pollutant
sources,
capture
of
runoff
containing
glycol
and
other
chemicals
used
to
deice
or
anti­
ice,
monitoring
of
storm
water
discharges,
discharge
requirements
for
reductions
in
pollutant
loading
through
implementation
of
best
management
practices,
and
an
annual
report
to
summarize
and
assess
compliance
with
permit
requirements.

SPECIFIC
PERMIT
CONDITIONS:

This
section
of
the
fact
sheet
describes
the
proposed
permit
requirements,
changes
from
the
previous
permit,
and
the
rationale
for
the
specific
conditions.
The
first
permit
was
issued
June
28,
1996,
and
expired
March
31,
2001.
The
permit
regulates
the
discharge
in
accordance
with
ch.
283,
Wis.
Stats.,
and
ch.
NR
102,
105,
106,
and
ch.
NR
216,
Wis.
Adm.
Code.
The
permit
incorporates
aspects
of
DNR's
storm
water
general
permit
for
industrial
facilities,
the
EPA's
storm
water
multi­
sector
permit
for
air
transportation
facilities
in
the
standard
industrial
classification
code
45,
and
the
oil
and
water
separator
general
permit.
An
individual
permit
instead
of
a
general
permit
will
regulate
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.

1.
Tenant
Coverage
The
airport
permit
cover
15
co­
permittees
under
one
permit.
This
allows
DNR
to
efficiently
regulate
Dane
County,
the
owner,
and
14
airport
tenants,
who
are
the
operators,
all
together
instead
of
through
Page
2
many
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.
Some
changes
in
tenants
have
occurred
since
the
first
permit.

2.
Applicability
This
permit
applies
to
Dane
County
Regional
Airport
within
the
jurisdiction
of
Dane
County,
and
includes
airport
tenants
as
co­
permittee.
Storm
water
runoff,
and
flows
contributed
by
process
and
nonprocess
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
the
means
for
addressing
compliance
with
water
quality
standards.

There
are
individual
and
joint
responsibilities
between
Dane
County
and
the
airport
tenants
who
become
co­
permittees.
The
airport's
storm
sewer
system
also
receives
inflows
from
off
site,
and
these
inflows
may
contribute
pollutants
to
the
storm
sewer
system.
And
discharges
from
non­
permitted
airport
tenants
may
also
contribute
pollutants.
The
airport
is
not
being
held
responsible
for
the
input
of
pollutants
from
off
site
or
from
tenants
who
are
not
co­
permittees.
These
other
pollutant
sources
will
be
addressed
by
the
Department
as
the
storm
water
program
progresses.

3.
Authorized
Discharges
The
permit
regulates
certain
discharges
of
storm
water
runoff
from
the
airport's
31
outfalls
into
Starkweather
Creek.
It
also
regulates
wastewater
discharges
from
the
glycol
retention
pond,
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
every
5
years.

Excluded
from
coverage
under
this
permit,
because
they
aren't
within
the
Department's
authority
to
regulate,
are
areas
of
the
airport
not
associated
with
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
The
storm
water
pollution
prevention
plan
is
the
major
component
of
the
permit.
The
plan
was
developed
under
the
previous
permit
and
was
submitted
in
December
1996.
Best
management
practices
have
been
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,
including
the
glycol
retention
pond.
Source
areas
of
pollution
were
evaluated
for
the
reduction
of
pollutants
entering
storm
water.
Pollution
prevention
is
an
ongoing
activity.

5.
In­
Plant
Requirements
(
Oil
and
Water
Separators)

There
are
13
oil
and
water
separators
at
the
airport,
serving
as
treatment
control
measures
at
fueling
or
fuel
storage
areas,
maintenance
areas,
and
fire
training
center.
Effluent
from
12
of
the
oil
and
water
separators
are
discharged
into
the
City
of
Madison
sanitary
sewer,
so
they
are
not
regulated
under
this
permit.
There
is
one
oil
and
water
separator,
installed
at
the
Wisconsin
Air
National
Guard
in
1999,
which
has
a
discharge
to
an
18
inch
storm
sewer
at
Outfall
034.
This
discharge
is
regulated
by
the
permit,
Page
3
and
must
comply
with
the
permit
requirements
to
be
an
authorized
non­
storm
water
discharge.
Special
conditions
for
the
operation,
effluent
limitations,
and
monitoring
requirement
reflect
those
from
the
oil
and
water
separator
general
permit.

6.
Surface
Water
Requirements
This
section
of
the
permit
contains
all
the
monitoring
to
evaluate
the
storm
sewer
discharges,
and
the
effluent
limitations
for
when
a
discharge
from
the
glycol
retention
pond
may
occur.
Monitoring
is
required
at
following
six
sampling
locations:

Sampling
Point
Description
001
Discharge
from
Glycol
Retention
Pond
into
Starkweather
Creek.
601
Instream
monitoring
required
for
a
Glycol
Retention
Pond
discharge.
003
and
022
Two
representative
storm
sewer
discharges
from
airport
into
Starkweather
Creek.
602
and
603
Starkweather
Creek
water
quality
monitoring
upstream
and
downstream.

Glycol
Retention
Pond
Plans
for
the
2
million
gallon
glycol
retention
pond
were
approved
September
10,
1991,
and
the
addition
of
aerators
to
control
odor
and
reduce
BOD5,
were
approved
July
12,
1994.
The
pond
operates
on
a
fill
and
draw
basis.
Storm
sewer
system
modifications
were
made
to
isolate
runoff
from
the
west
apron
adjacent
to
the
terminal,
where
94%
of
the
glycol
is
applied
to
aircraft.
Approximately
50%
of
the
glycol
drains
off
the
aircraft
onto
the
apron
area.
The
runoff
from
the
west
apron
area,
consisting
of
13.9
acres
served
by
non­
perforated
storm
sewers,
is
diverted
into
the
glycol
retention
pond.
Storm
water
runoff
is
retained
in
the
pond
during
the
deicing
season.
During
the
rest
of
the
year,
storm
water
uncontaminated
by
glycol,
passes
through
the
pond
and
into
Starkweather
Creek.
The
majority
of
runoff
from
other
areas
of
the
airport,
which
doesn't
appear
to
be
a
significant
source
of
pollutants,
discharges
directly
into
Starkweather
Creek.

Specific
effluent
limitations
apply
to
the
discharge
from
the
glycol
retention
pond
at
Outfall
001.
If
limits
aren't
met
the
wastewater
is
discharged
to
the
sanitary
sewer,
and
the
airport
is
subject
to
the
requirements
of
the
Madison
Metropolitan
Sewerage
District.
Discharges
into
the
sanitary
sewer
are
also
made
if
the
capacity
of
the
glycol
retention
pond
is
approached
and
it
must
be
drawn
down
during
the
deicing
season
to
maintain
storage
capacity
for
runoff
events.
The
water
quality
based
weekly
mass
BOD5
limitations
in
this
permit
are
based
on
an
allowable
discharge
of
26
pounds
of
BOD5
per
day
per
cfs
of
stream
flow,
modified
for
temperature.
To
address
glycol
discharges,
BOD5
is
used
to
indirectly
regulate
it
because
of
the
oxygen
demands
of
glycol.
Other
parameters
monitored
in
the
current
permit
include
COD,
TSS,
pH,
oil
&
grease,
TKN,
ammonia,
phosphorus,
glycol,
lead,
zinc,
and
hardness.
Based
on
the
monitoring
data
for
oil
&
grease,
total
glycol,
lead,
zinc,
and
hardness,
these
parameters
will
no
longer
be
monitored
because
concentrations
are
below
levels
of
concern.
Ammonia
and
phosphorus
must
continue
to
be
monitored
since
they
are
added
as
nutrients
to
the
glycol
retention
pond
for
effective
treatment.

To
protect
water
quality,
before
a
discharge
from
the
glycol
retention
pond
is
allowed
Starkweather
Creek
must
have
a
minimum
flow
of
1
cfs
and
dissolved
oxygen
of
7
mg/
L.
Instream
monitoring
is
done
at
a
gauging
station,
identified
as
Sampling
Point
601,
located
approximately
1400
feet
downstream
from
Outfall
001.
In
addition,
the
wastewater
must
be
monitored
prior
to
and
during
the
discharge
to
assure
compliance
with
effluent
limitations.
The
BOD5
may
not
be
greater
than
50
mg/
L,
which
serves
as
a
treatment
performance
standard.
The
BOD5
mass
limitation
is
dependent
on
the
effluent
concentration,
effluent
flow,
stream
flow,
and
temperature.
By
knowing
the
BOD5
concentration,
stream
flow,
and
time
of
year
(
temperature
factor),
the
effluent
flow
rate
can
be
adjusted
so
the
daily
mass
limitation
is
met.
A
table
is
provided
in
the
permit
showing
the
BOD5
concentration
and
mass
limits
per
1
cfs
of
flow.
Similar
limitations
apply
to
ammonia.
Because
the
runoff
is
nutrient
deficient,
nitrogen
and
phosphorus
have
been
added
to
the
glycol
retention
pond
for
the
biological
treatment
of
the
glycol
to
maintain
a
proper
nutrient
ratio
(
350
­
900
pounds
of
nitrogen
and
70
­
350
pounds
of
phosphorus
typically
added).
Page
4
The
glycol
retention
pond
discharge
was
evaluated
in
the
first
permit
as
a
new
discharge
for
the
purpose
of
the
antidegradation
requirements
in
ch.
NR
207,
Wis.
Adm.
Code.
Effluent
mass
limitations
reflect
this
by
using
only
a
third
of
the
available
assimilative
capacity
of
Starkweather
Creek
to
prevent
a
significant
lowering
of
water
quality.
Only
if
it
is
found
that
the
use
of
cost
effective
measures
don't
prevent
the
significant
lowering
of
water
quality
would
the
effluent
limitations
be
the
full
value
for
BOD5
and
ammonia.

The
first
permit
includes
a
20
mg/
L
TSS
limit
for
the
glycol
detention
pond
discharge.
The
origin
of
why
this
limit
was
included
is
unknown
and
appears
to
be
a
mistake.
The
proposed
TSS
limit
for
the
reissued
permit
is
a
daily
maximum
of
50
mg/
L,
so
it's
the
same
as
the
BOD5
limit.
Permit
limits
for
BOD5
and
TSS
are
normally
the
same.
A
BOD5
concentration
limit
was
included
in
the
effluents
limits
memo
for
the
first
permit
as
a
best
professional
judgment
for
the
treatment
capability
of
the
glycol
retention
pond.
The
new
effluent
limits
memo
references
the
previous
20
mg/
L
limit,
but
since
that
limit
was
incorrect
it
will
not
be
used.
Similarly,
because
the
50
mg/
L
limit
is
replacing
a
limit
that
was
in
error,
an
antidegradation
review
according
to
ch.
NR
207,
Wis.
Adm.
Code,
in
not
applicable.

Storm
Sewer
and
Starkweather
Creek
Monitoring:

A
monitoring
program
collects
storm
water
runoff
quality
data
to
evaluate
storm
water
best
management
practices.
Dane
County
Regional
Airport's
proposed
monitoring
program
meets
the
airport's
needs
in
evaluating
the
storm
water
pollution
prevention
plan.
The
minimum
monitoring
requirements
are
contained
in
this
section
of
the
permit,
but
the
airport
may
need
to
conduct
other
monitoring
as
appropriate
to
evaluate
specific
storm
water
best
management
practices.
The
permit
includes
the
following
monitoring
program
elements:

 
Visual
quarterly
inspections
of
discharges
 
Collection
of
storm
water
samples
for
chemical
analysis
 
Collection
of
receiving
water
samples
to
assess
impairment
or
improvement
Procedures
for
visual
inspections
and
chemical
analysis
are
described
in
the
permit.
Monitoring
is
done
at
two
representative
storm
sewer
outfalls
from
the
airport
(
Sampling
Points
003
and
022).
Added
to
the
permit
are
new
upstream
and
downstream
locations
in
Starkweather
Creek
to
assess
the
impact
of
the
airport
on
receiving
water
quality
(
Sampling
Points
602
and
603).
The
chemical
sampling
of
the
storm
sewers
requires
an
analysis
of
ethylene
glycol,
propylene
glycol,
BOD5,
COD,
TSS,
oil
&
grease,
dissolved
oxygen,
and
pH.
The
chemical
sampling
of
Starkweather
Creek
requires
an
analysis
of
BOD5,
COD,
TSS,
dissolved
oxygen,
and
pH.
The
previous
permit
required
two
rounds
of
chemical
sampling
of
the
representative
storm
sewers
for
14
parameters.
This
list
of
parameters
was
reduced
by
eliminating
those
substances
below
concentrations
of
concern.
Sampling
is
now
required
annually
during
a
deicing
or
anti­
icing
event
to
continuation
the
evaluation
of
runoff
quality.

General
narrative
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
will
be
evaluated.
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.
Specific
numeric
effluent
limitations
aren't
included
in
the
permit
for
the
storm
water
outfalls.
Chapters
NR
102
through
NR
105,
Wis.
Adm.
Codes,
which
contain
the
water
quality
standards,
currently
are
not
applicable
to
storm
water
because
these
administrative
codes
don't
contain
procedures
to
address
the
intermittent
nature
of
storm
water
discharges.

7.
Groundwater
Requirements
To
detect
any
leakage
from
the
glycol
retention
pond,
four
groundwater
monitoring
wells
were
installed
around
it
as
required
in
the
plan
approval
for
the
glycol
retention
pond.
The
monitoring
wells
are
sampled
twice
annually
for
groundwater
elevation,
depth
to
groundwater,
BOD5,
COD,
pH,
total
dissolved
solids,
and
conductivity.
Groundwater
flows
to
the
southwest
toward
Starkweather
Creek.
Page
5
Monitoring
well
No.
801
is
the
upgradient
background
well.
Preventative
action
limits
were
calculated
from
background
well
data
collected
to
date.
The
standard
conditions
for
groundwater
monitoring
are
included.

8.
Schedules
of
Compliance
(
Annual
Report)

This
section
lists
required
permit
activities,
with
references
to
the
permit
sections
that
contains
the
requirement,
and
due
date.
Requirements
are
included
for
a
comprehensive
annual
site
inspection
to
verify
conditions
at
the
airport,
and
annual
report
summarizing
permit
activities.
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
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
9.
Standard
Requirements
The
relevant
standard
requirements
typical
to
all
WPDES
permits
are
included.
These
consist
of
requirements
for
reporting,
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
Watershed
Management
and
the
South
Central
Region
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:

Dane
County
submitted
the
permit
reissuance
application
for
Dane
County
Regional
Airport
September
20,
2000.
Five
annual
reports
summarizing
monitoring
data
and
compliance
with
storm
water
management
requirements
were
submitted
as
scheduled
to
document
compliance
with
the
permit.
All
other
compliance
schedule
dates
were
complied
with.

The
following
table
summarizes
glycol
usage
per
deicing
season,
and
estimated
amount
of
glycol
captured
in
the
glycol
retention
pond.
Data
shows
a
trend
in
reduced
glycol
usage
and
increased
glycol
captured.
The
glycol
retention
pond
appears
to
be
effective
in
preventing
the
runoff
of
glycol.
And
when
considering
that
50%
of
the
glycol
is
considered
fugitive,
the
airport
is
capturing
about
80%
of
the
collectable
glycol.

Gallons
of
Gallons
of
Glycol
Pounds
of
BOD5
%
Glycol
Deicing
Season
Glycol
Used
Captured
in
Pond
Captured
in
Pond
Captured
1996
­
1997
73,400
21,572
98,153
29.4
1997
­
1998
40,724
16,308
89,041
40.0
1998
­
1999
32,285
12,178
66,491
37.7
1999
­
2000
39,188
17,117
93,457
43.7
2000
­
2001
60,165
25,679
139,206
42.7
Average
49,152
18,571
97,270
38.7
Page
6
Discharges
of
treated
runoff
from
the
glycol
retention
pond
to
Starkweather
Creek
have
occurred
every
spring
for
about
a
one
week
period.
Effluent
quality
and
mass
loadings
have
been
in
substantial
compliance
with
discharge
limitations.
Total
suspended
solids
have
sometimes
exceeded
the
limit,
with
a
high
of
170
mg/
L
in
May
1998.
The
higher
concentrations
were
attributed
to
the
growth
of
algae
in
the
pond.
The
corrected
TSS
limit
of
50
mg/
L
should
be
met
consistently,
with
only
an
occasional
higher
concentration
due
to
algae.
The
following
table
summarizes
the
average
effluent
quality
during
the
term
of
the
first
permit.

Parameter
1996
­
1997
1997
­
1998
1998
­
1999
1999
­
2000
2000
­
2001
Volume
(
MG)
5.76
1.27
2.39
5.48
2.04
BOD5
(
mg/
L)
12
6
12
<
40
18
COD
(
mg/
L)
44
45
72
128
80
TSS
(
mg/
L)
34
13
10
17
30
Oil
&
Grease
(
mg/
L)
<
1.0
<
1.0
<
1.0
<
1.0
1.8
pH
(
su)
8.8
8.0
7.8
7.4
7.3
TKN
(
mg/
L)
2.3
3.0
2.7
4.1
3.8
Ammonia
(
mg/
L)
0.14
1.07
0.28
0.78
1.39
Phosphorus
(
mg/
L)
0.17
0.25
0.14
0.34
0.39
Total
Glycol
(
mg/
L)
<
10
<
1
<
10
<
10
<
10
Lead
(
µ
g/
L)
1.2
<
35
<
1.4
<
35
<
35
Zinc
(
µ
g/
L)
17
42
<
29
52
<
15
Hardness
(
mg/
L)
110
200
165
155
190
Quarterly
monitoring
during
two
sampling
rounds
collected
monitoring
data
to
characterize
runoff
quality
from
two
representative
storm
sewers
located
outside
the
glycol
management
area.
The
results
are
summarized
in
the
following
table,
which
shows
the
range
in
concentration.
Data
shows
storm
water
runoff
from
the
airport
separate
storm
sewer
system
is
generally
of
good
quality,
but
on
occasion
is
a
source
of
pollutants
(
detection
of
glycol
and
elevated
BOD5)
during
the
deicing
season,
which
runs
from
October
through
April.
Monitoring
will
be
discontinued
for
TKN,
ammonia,
phosphorus,
copper,
lead,
zinc,
and
hardness
because
concentrations
were
below
levels
of
concern.

Parameter
1997
­
1998
1999
­
2000
Dissolved
Oxygen
(
mg/
L)
7.4
­
7.7
8.3
­
10
BOD5
(
mg/
L)
<
3
­
230
<
4.5
­
160
COD
(
mg/
L)
12
­
240
<
7.3
­
310
TSS
(
mg/
L)
1
­
17
1
­
220
Oil
&
Grease
(
mg/
L)
<
1
­
93
<
1
­
1.5
pH
(
su)
7.4
­
8.1
7.0
­
8.4
TKN
(
mg/
L)
0.08
­
0.85
<
0.21
­
1.6
Ammonia
(
mg/
L)
<
0.1
<
0.1
­
1.3
Phosphorus
(
mg/
L)
0.027
­
0.14
<
0.10
Total
Glycol
(
mg/
L)
<
1
­
<
10
<
10
­
37
Copper
(
µ
g/
L)
<
2.3
­
2.6
<
2.3
­
5.9
Lead
(
µ
g/
L)
<
35
<
35
­
110
Zinc
(
µ
g/
L)
17
­
100
28
­
100
Hardness
(
mg/
L)
270
­
480
160
­
450
The
groundwater
monitoring
wells
around
the
glycol
retention
pond
generally
do
not
have
concentrations
of
substances
at
a
level
of
concern.
Unexpected
and
unexplained
increased
concentrations
of
BOD5
and
COD
occurred
in
1997
and
1998
at
some
of
the
wells,
but
data
has
since
returned
to
normal.
The
increase
was
not
due
to
the
glycol
because
it
was
not
present
in
the
samples.
This
indicates
the
pond
liner
isn't
leaking,
and
the
perforated
storm
sewers
aren't
leaking
pollutants
that
could
impact
groundwater
quality.
The
following
table
summarizes
the
groundwater
monitoring
data
collected
during
the
term
of
the
first
permit
and
submitted
with
the
annual
reports
(
excludes
abnormal
data):
Page
7
Parameter
Well
801
Well
802
Well
803
Well
804
BOD5
(
mg/
L)
<
13.5
<
7.6
<
5.4
<
22.7
COD
(
mg/
L)
29
9.6
11.5
41
pH
(
su)
6.9
7.4
7.4
7.1
TDS
(
mg/
L)
910
500
760
830
Conductivity
(
µ
mhos/
cm)
1180
650
970
1130
Depth
(
feet)
11.63
9.67
8.27
7.92
The
previous
permit
included
requirements
for
potential
discharges
from
groundwater
remediation
projects
at
the
airport
associated
with
the
fuel
systems
and
other
locations
with
petroleum
contaminated
soil
or
groundwater.
Because
no
remediation
projects
exist
or
are
expected,
this
section
of
the
permit
is
being
deleted.

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,
especially
the
collection
and
treatment
of
contaminated
runoff
in
glycol
retention
pond,
is
the
permit's
means
to
comply
with
water
quality
standards.

Prepared
by:

Paul
W.
Luebke,
P.
H.
Wastewater
Permits
and
Pretreatment
Section
Bureau
of
Watershed
Management
attachment:
Water
Quality
Based
Effluent
Limits
Memo
September
20,
2001