ILLINOIS POLLUTION CONTROL
BOARD
April
19,
1984
IN THE MATTER OF:
)
)
SULFUR DIOXIDE EMISSION
)
R80—22(B)
LIMITATIONS;
VILLAGE OF WINNETKA
)
ADOPTED RULE.
FINAL OPINION.
OPINION OF THE
BOARD
(by 3.
D.
Dumelle)
At the outset, this rulemaking included a proposal by the
Illinois Environmental Protection Agency
(Agency) to limit the
sulfur dioxide emitted from existing fuel combustion sources
in the Chicago,
St. Louis
(Illinois)
and Peoria major metropol—
itan areas to 1.8
pounds
per million British thermal units
(lbs/mBtu)
of actual heat input.
The Village of Winnetka (Vil-
lage)
sought to include a site specific rule so that its utility
plant could emit up to 5.7 lbs/mBtu of sulfur dioxide.
A draft
Opinion was issued by the Board on August 30,
1982 and the rules
proposed for First Notice were published on September 17,
1982.
The Opinion proposed to deny the Village the requested site-
sp~cificlimitation for two reasons.
Although the Village
had
participated
in
the rulemaking,
it
was not until hearings
in
June
o~
1982 that
the
specifics and the supporting evidence
of
the Village’s request became known.
The
Board
reasoned that
this
did
not
provide
sufficient
time
for
notice
to
or
response
fro~!iconcerned
public.
Secondly,
the
draft
rules
in
R80—22
included
an
adjudicatory
format
for
existing
individual
sources
t~o
seek
relaxed,
alternative
limits.
tn
the
draft
Opinion,
the
Board
cited
the
Village’s
utility
plant
as
a
possible
candidate
for
the
new
exemption
procedure.
Preferring
a
site—specific
rule,
the
Village
exercised
its
right to request an additional hearing during the
First
Notice
period
(Ill.
Rev.
Stat.
1981,
ch.
127,
par.
1005.01(a)).
On
C)ctober
8,
1982
the
request
was granted and the subject
of
the additional hearings limited to
the
Village’s
petition.
To
avoid delaying
the
adoption
of
the
rules
already
proposed,
on
October
14,
1982
the
Board
ordered
the
R80-22
docket
divided
and
the
Village’s
site—specific
rulemaking
assigned
to
Docket
B.
When
the
proposed
rules
(Docket
A)
were
adopted
as
final
on
February
24,
1983,
the
Village’s
utility
plant
was
exempted
~rom
the
1.8
ibs/ingtu
limit
pending
the
outcome
of
Docket
B.
This
Opinion
principally
pertains
to
Docket
B,
After
separating
the
Village’s
request
from
the
whole
of
R~3O—22, two
more
hearings
were
held
in
Winnetka
on
November
3
57-467
2
and December 15,
1982.
As noted above,
information pertaining to
the Village’s request was also entered at the June
1 and 22, 1982
hearings.
On
December
1,
1983 the Board adopted a proposed rule
and an Opinion supporting the same on December 29,
1983.
The
proposed rule was published
on
December
18,
1983
for
First
Notice
in 7 Illinois Register 16634.
In
response
to
comments
received,
the proposed rule was amended and adopted for Second Notice on
February 22,
1984.
The Joint Committee on Administrative Rules
issued a certificate of no objection on April
10,
1984.
Where Tower Road meets Lake Michigan in Winnetka, the Village
owns
and
operates an electrical generating plant which supplies
the
power
needs
for
the Village’s 13,000 residents and small
businesses.
There
are
no
major
industrial
users
within
the two
and half
mile
radius
serviced
and
the
Village
does
not
generate
additional
power
for
sale,
(R.
843)
On
site
are
five
boilers
and
two
diesel
generators.
Two
boilers
are
in
wet
storage
and
are
not
currently
permitted
by
the
Agency;
a
third,
Boiler
No.
4,
is
permitted
to
operate
on
gas
or
oil.
Boiler
No,
8,
which was
built in 1964,
is the principal power source with a rated capacity
of 125,000 pounds of steam per hour or 12.5 megawatts.
This
boiler is equipped with a multiclone dust collector and ash
recirculation.
Boiler No,
7, built in 1948,
also operates on
coal and has
a rated capacity of 70,000 pounds of
steam per hour
or
65 megawatts.
130th diesels were installed in 1979 and are of
a rated capacity of 2,500 pounds
of steam per hour,
All seven
sources vent from a common stack.
Currently,
boiler No,
8 produces
85 to 87 percent of Winnetka’s energy needs on a day to day
basis.
Boiler No.
7 is used to generate the additional electricity
when the demand is predicted for a period greater than eight
hours.
If not, Boiler No,
4 or the diesels are utilized.
Annually,
Boiler No,
7 provides approximately only
2 percent of the necessary
kilowatt hours.
(R,852)
Of the 23 million tons of coal consumed annually by Illinois
utilities,
the Village’s plant consumes approximately either
45,000 tons of Illinois coal or 54,000 tons of western coal,
(R.1053)
Twenty percent more western coal must be purchased
to
make up for its lower heat value and higher moisture content.
Including delivery costs western coal costs approximately
$75
per
ton, whereas Illinois coal costs approximately $53 per ton.
The
Village
is currently burning Illinois coal,
specifically coal
from Orient
No,
3 mine, pursuant to a permit issued by the Agency
in April,
1982.
Since the Village has been allowed to use Illinois
coal
it has provided
90 percent of Winnetka’s electricity (R,899)~
Under a short term contract,
450 tons are delivered weekly after
being screened and washed to reduce the sulfur content and dust.
Since Illinois coal has been used, the highest sulfur content
measured has been 2.14 percent.
The Village is requesting to
use
Illinois coal with a maximum sulfur content of 3.2 percent
(R. 911,877),
57-468
3
To demonstrate that Illinois coal of this quality could be
burned at its power plant, without installing additional pollution
control equipment and without violating applicable ambient air
quality
standards,
the
Village
offered
a
two
part modeling study
(Ex.
12
and
Ex.
22).
Particulate
matter
concentrations,
as well
as sulfur dioxide concentrations were calculated.
The first
phase considered the actual operating requirements during 1979.
That
is
Boiler
No.
8
was
assumed
to
provide
the
baseload,
with
Boiler
Nos.
4 and
7 and
the
diesels
providing
additional
power
when
necessary.
The
second
phase
assumed
both
Boiler
Nos,
7
and
8
at
full
load.
Aside
from those parameters premised
on the
hypothetical
load,
the
input
data
remained
much
the
same
for both
parts
of
the
study.
At
each
phase,
two
computer
runs
were made
each
assuming
the
use
of
a
different
Illinois
coal,
that
from
Orient No.
3 mine and from Fidelity No.
11 mine.
The dispersion model developed and used by the
Village was
premised
on
the
United
States
Environmental
Protection
Agency’s
(USEPA)
Single Source Model known as the CRSTER.
The
data require-’
rnents,
processing
techniques
and
input/output
formats
were modified
to develop a non—guideline, Case
1 model.
The
principle variation
was premising the atmospheric stability data on meteorological
data from the
Zion nuclear power plant,
23
miles to the north, as
opposed to that from Midway and O’Hare Airport which are eight
and twelve miles inland,
respectively.
The Zion meteorological
data satisfies the federal requirements
(10 CFR 50,
App.
B), hut
the CRSTER model had to be modified to accommodate this more
representative lakefront information.
Mixing heights were specif-
ically developed for this site based on real information compiled
by Argonne National Laboratory for the Chicago area in the late
1960’s instead of predicting values
from vertical temperature
profiles and hourly surface temperatures (Holzworth inferential
technique).
To verify that the changes did not substantially
alter the CRSTER’s program,
the modified program was tested using
24 hours of test data from the CRSTER model.
The differences
in
result were within 0.2 percent.
The Village’s modeling was intended to calculate hourly
concentrations for an entire year.
It used a grid consisting of
ten down range receptors and seventy—two radials,
Consequently
the running
3 hour and 24 hour concentrations,
as well as the
annual arithmetic/geometric mean concentrations were measured at
720 locations over the surrounding lake and land mass.
From
these predictions the highest concentrations of the pollutant
could he identified and assessed against the applicable air
quality standards.
The modeling program included certain constants.
The stack’s
diameter was set at three meters,
the temperature at
3500
F,
(or
3750
F for the full load model)
and its height at 57 meters.
At
this height the stack is considered consistent with good engineer-
ing practice,
that is, high
enough above the plant’s roof and
57-469
4
other obstructions to avoid interference or induced turbulence.
Rural dispersion coefficients were used instead of urban coeffi-
dents,
According to USEPA methodology, given the non-industrial
characteristics of the Winnetka area,
these are more appropriate
than the latter.
The reference plane was the plant’s rooftop which
was
level with the 19 meter high bluff the plant abuts to the west.
This
was
the
only
terrain
factor
taken into account.
Other
program
input
varied
on
an
hourly
basis.
Wind
speeds,
directions,
temperature,
and atmospheric stability were included
at actual hourly values from 1979.
Representative values for
boundary
levels
were
selected
from
real
mixing
height
data
based
on the Argonne study.
A value
of 1000 meters was used for
daylight hours;
100 meters for night hours when wind speeds were
equal
to
or less than 10 miles per hour;
and 200 meters when wind
speeds were higher.
These hourly values,
along with the above
described constants,
were run first, with the coincident operating
loads
actually
experienced
in
1979,
and
then
again
assuming
Boiler Nos.
7 and
8 to be operating at full
load.
The size of
the load,
as well as the heat value of the coal can alter the
stack gas exit velocity and the amounts of sulfur dioxide emitted.
The following table lists the highest concentrations predicted at
both loadings, along with sulfur content and heat value for each
type of
coal.
TABLE
1
Sulfur
Heat
Coal
Content
Value
Load
Annua~
24 Hour
3 Hour
*
——
(8Oug/m
)
(365u~j~)(l300u~a/m)
Orient
T,77
T17780
Btu/lb
Actual
2
69
318
No.
3
Full
2
71
361
Fidelity
3.19
11,054 Btu/lb
Actual
4
133
610
No.
11
Full
4
132
618
The modeling assumed background concentrations to be zero.
However,
adding
the
model’s
highest
predicted
values
and the highest
measurements recorded at nearby monitors in Skokie, Wilmette and
Waukegan provides an estimate of the combined impact,
should the
Village be granted the relaxation.
These estimates are the
hypothetical worst case scenarios,
since the highest values from
the model and monitors are being added regardless of the time and
date predicted or recorded.
Table
2 compares the sum totals to
the short term and annual standards,
using values measured in 1980~
(Monitored values reported for 1981 were checked and found to be
lower).
57-470
5
TABLE
2
(ug/m3)
Coal
Modeled
Measured
Sum
Standard
Orient
#3
Annual
2
25
27
80
24—Hour
69
165
234
365
3—Hour
318
291
609
1300
Coal
Modeled
Measured
Sum
Standard
Fidelity
Annual
4
25
29
80
#11
24—Hour
133
165
298
365
3—Hour
610
29.1
901
1300
In proposing the
1.8 lbs/mBtu limit for the Chicago major
metropolitan area,
the Agency identified only two sources as
possible candidates
for a more relaxed limitation.
(R.
562)
For
that reason it did not generally propose a higher emission rate.
The Village’s power station was one of those two sources.
An
Agency memorandum of January 21,
1982 evaluating the Village’s
modeling found that a 5,7 lb/mBtu limit would not cause
violations of the short term standards.
(Ex.
11)
However,
the
Agency considered additional modeling necessary.
(P.
596)
The Village completed its modeling analysis
in March,
1982 and
submitted additional
information pursuant to Agency’s inquiry.
The Agency
in turn evaluated the model
to verify that it was
conservative.
It used the guidelines recommended
in the CRSTER
model and maximum load at 5,7
lbs/mBtu was assumed for every hour
of the entire year.
Evaluation of only one year was considered
necessary since on-site data had initially been used.
The Agency’s verification run only assumed the use of
Fidelity No.
11 coal since it has the highest sulfur content of
the two types.
Like the Village’s model,
it did not include back-
ground levels.
As indicated below in Table
3, the Agency’s model
resulted in levels proximate to or below those predicted by the
Village’s single source modified model.
Using the same methods
and background levels assumed by the Village, the hypothetical
impacts are also calculated,
TABLE~~j~3)
Village
Agency
Village
Agency
Standard
~j~!t
~
~~round
~~ound
p~~round
Annual
(8OugIm3~
4
5.6
25
29
24 Hour
(365ug/m3)
133
66
165
298
231
3 Hour (l300ug/m3)
610
315
291
901
606
57-471
6
Comparison of the above figures indicates that the Agency’s model-
ing verifies that the Village’s model was conservative when com-
pared to the CRSTER model.
The Village investigated installation of pollution control
equipment in order to meet the 1,8 lbs/ml3tu limit and still
utilize Illinois coal.
Installation of wet scrubbers was
estimated to necessitate capital expenditures of $3.2 million
dollars.
However, this alternative was prohibitive, not due
to the costs, but because land was not available to facilitate
storage facilities,
slurry mixing plants,
slurry holding areas,
venture and separators.
The Village also noted that the
delivery of
lime,
the noxious odors created by the formation
of hydrogen—sulfide gas and the increased steam plume would
be a nuisance to the plant’s residential neighbors.
(P.
836)
By
interim order, the Board requested that the Village investigate
the
possibility
of
dividing
its
stack
in
order
to
increase
exit
velocity.
It was hoped that the resulting increased plume rise,
in combination with the plant’s
stack height,
could negate any
effect the lake breezes might have
in increasing downwash or
boundary
interference and reduce alleged odor nuisances.
Divi-
sion proved impossible since the stack is made of metal.
The
Village’s
engineers
also
noted
that
increased
exit
speed
will not
affect final plume rise because
it
is a function of volumetric
flow, which is
a constant,
(Public Comment #30).
The Economic Impact Study prepared by the Department of
Energy and Natural Resources did not specifically consider the
Winnetka facility and the economic ramifications should
it be
allowed to burn Illinois higher sulfur coal.
The Village did
provide numerous details.
From 1958 until
1975 it made an esti-
mated profit of $11,999,000 or $638,000 per year.
$3 million of
that
was
paid
to
the
Village
in
dividends.
Another
$1.5 million
was contributed
to the Village’s operating expenses.
(P.
976)
The net worth of the plant was $3,710,000 in 1957,
$8,613,000
in
1975 and $11,000,000 in 1982,
Improvements at the plant were paid
for out of earnings.
Before 1971, the plant supplied all of the Village’s energy
needs.
Then
an
interconnect
with
Commonwealth
Edison
was com-
pleted.
By 1973 the Village was purchasing base load power and
generating
power
only
to
meet
intermediate
and peak power de-
mands.
To
keep
purchase
power
costs
at
4.1~ per
kw/hr
in
the
late 1970’s and early 1980’s the Village continued to generate
intermediate and peak power.
If
it did not the price would have
been 5.5~per kw/hr.
The Village also sought to keep minimal its
firm or demand power costs from Commonwealth Edison.
Since
burning Illinois coal under the Agency issued permit, the Village
has been producing over
90 percent of its energy demands and
purchasing only economy power from Commonwealth Edison.
57-472
7
In addition to the lower power costs and revenue generated
which aid
its residents,
the Village claimed socio—economic bene-
fits due to its plant’s operation on Illinois coal,
The Village
is committed to using Illinois coal and although it will not
purchase large amounts of
it,
some increased economic activity
should be generated in Illinois.
The Village’s plant employs
18 persons.
Finally,
the Village anticipates that it will he
able to provide its residents with power when other areas are
experiencing power outages.
Several examples of power failures
were
testified
to
during
hearing,
but
the
Village countered that
these occurred while
it was buying from Commonwealth Edison,
prior
to
its
burning
Illinois
coal.
At
hearing, Citizens for a Better Environment
(CBE)
proferred
a critical review of the modeling analysis provided by the Vil-
lage.
The review was three part:
(1)
a discussion of the coast-
al meteorological adversely affecting pollutant dispersion;
(2)
the inapplicability of the Village’s model and the underlying
CRSTER model
in assessing the Village’s lakefront facility;
and
(3) specific problems with select model
input data and modeling
assumptions.
CBE’s presentation was subsequently reviewed and
commented
on
by
the
Village,
to
which
CBE
responded
at
hearing
and in written comments.
CBE began with an explanation of meteorological phenomena
pertinent to coastal environments.
Of primary concern in evalu-
ating adverse effects to pollution dispersion at the shoreline is
the thermal internal boundary level
(TIBL).
A TIBL, which con-
sists of heat moisture and momentum, forms due to the physical
discontinuity of water and land surfaces when the
cold. water sur-
face air comes into contact with warmer land surface air.
The
TIBL starts at the shoreline and its height gradually deepens to
a maximum of 500 feet as the distance inland increases.
If the
stable plume from the stack intercepts with the TIBL,
fumigation
results;
if it is below the TIBL’s ceiling, trapping results.
Fumigation occurs primarily on sunny days, whereas trapping
occurs on overcast days or at night.
Either condition affects
ground level concentration of pollutants.
CBE suggested several models developed to specifically
address the effects of lake breeze circulation and gradient
onshore flow on TIBL formation which would have been preferable
to accurately predict ground level concentrations for the Win-
netka facility.
Furthermore, CBE believed that the modified
CRSTER model developed by the Village was inappropriate because
the underlying model was applicable to rural
areas uncompli-
cated by terrain and coastal
influences.
As such it did not suf-
ficiently account for maximum ground level concentrations under
conditions of gradient onshore flow,
continuous fumigation or
lake breeze circulation,
CBE acknowledged that the Village’s use of meteorological
57-473
8
data from Zion was preferable to that from Midway or O’Hare.
However,
it disagreed with the method the Village
used
this
data
to determine atmospheric stability.
That method,
known as
the
Delta
T method, CBE argued was for low emission sources
such as
nuclear reactors, not stacks at fossil
fuel plants.
CBE also
disagreed with the use of the power law formula to extrapolate
windspeeds
for measure at
10 meters at the Zion tower,
Since
windspeeds were also measured there at 38 and 76 meters,
CBE
argued that these would have been preferable.
Finally,
CI3E
argued that the constant mixing heights chosen by the Village did
not adequately take into account deviations caused by TIBLs.
In response, the Village verified that the Delta T method
was appropriate for determining atmospheric stability in modeling
its facility.
(Ex.
24,
25)
The Village believed it preferable
because it requires the fewest assumptions
(R.
1258).
CBE later
agreed that the Delta T method was appropriate
for sources with
stacks as low as the Village’s but offered that it
should
not be
relied on solely.
(P.C.
23, at 34)
As for wind speeds, the
Village compared those measured at
76 meters at the Zion facility
to those derived by the power law formula and found them similar,
(P.
1263)
Finally, the Village explained that its model took
into consideration trapping since the modeled plume height was
less than the assumed mixing heights during both daytime and
nightime calculations.
Its model assumed the presence of a TIBL,
but its height was always considered greater than the stack’s
plume rise.
Had lesser mixing height values been modeled, the
Village alleges that lower ground levels would have been pre-
dicted.
The Village contends that these assumptions make
the
model more conservative,
(P.
1267—71)
Although its model ac-
counted for trapping,
it did not consider the effects of fumiga-
tion.
According to the Village,
fumigation was not of practical
concern since six conditions would have to exist simultaneously,
but also because it believed the modeled facility’s plume height
never to be higher than the boundary’s ceiling, making intercep-
tion,
i.e.
fumigation, impossible.
The critical review provided by CBE raised alternative
modeling parameters and suggested that a site specific model
would be appropriate.
CBE believed a number of models to be more
appropriate in assessing pollution dispersion from the lakefront
facility.
Prior to CBE’s review,
the Agency believed the data
input to be sufficiently source specific that only one year be
considered under worst case conditions.
There is no federally
approved
modeling
program
for
lakefront
or
coastal
environments.
After
CBE’s
critical
review,
the Agency still
believed
the model-
ing adequate for the proposed relaxation to be approved federally.
Given
the
responses
to the inquiries posed by CBE, the Board
is able to conclude that the Village’s modeling incorporated
sufficient meteorologial data similar to that likely to occur at
57-474
9
and near its facility.
Also it used techniques considerate of
lakefront atmospheric conditions, and violations of the applic-
able standards are not approached.
The record
in this matter now
includes the parameters developed for the facility,
as well
as an
assessment of alternatives.
Short of developing site specific
meteorological information,
the Village’s model
as developed,
adequately accounted for the lakefront environment and indicated
that
the
applicable
air
quality
standards
and
public
health and
welfare
will
not
be
endangered.
Furthermore,
since
the facility
and
its
emissions
are
considered
to
be
small
and
the
Zion
meteo-
rological data was used,
a site specific model
is unwarranted.
Having reviewed the testimony and comments on the modeling format
and the results, the Board concludes that the ambient air quality
standards for sulfur dioxide are not violated and an adequate
margin of safety for health and growth is preserved.
The Winnetka
facility is located
in a residential area with stabilized energy
demands.
The surrounding area is also unlikely to be developed
industrially.
Therefore,
the
Board
need
not
assess
hypothetical
consumption of Prevention of Significant Deterioration increments.
Citizens from Wirinetka testified concerning odor and noise
nuisances associated with this facility.
Likewise citizens
testified about not having experienced such nuisances,
The issue
of
odor
is
highly
debatable.
Different
persons
experience dif-
ferent sensitivity thresholds.
Furthermore,
it
is difficult to
isolate an odor to its source at a particular point in time.
That time would also be difficult to relate to the
3 or 24 hour
air quality standards
for
sulfur
dioxide.
The
Agency
submitted
data from the U.S. Department of Transportation which
lists the
sulfur dioxide odor threshold at
3 parts per million, which can
be converted to 7,873 micrograms per cubic meter,
(P.
1298)
This is significantly greater than the applicable
standards.
Although the questions of odor and noise nuisance are not
properly before the Board in this
rulemaking,
the
citizens’s con-
cerns were addressed in the Board’s order for additional informa-
tion.
The Village responded that it had not received or been
notified of nuisance complaints since May of 1982.
(P.C.
30)
The Village also explained a malfunction, but did not believe it
caused any environmental problems.
Finally, the Village submitted
correspondence between itself and a resident exchanged to resolve
a noise problem.
This rulemaking solely addresses sulfur dioxide emissions.
Nevertheless the Board would be reluctant to grant a relaxation
which would in turn aggravate another environmental problem.
In
this instance the alleged odors nuisances are not documented to
be linked to the use of medium sulfur coal at the facility since
Spring of 1982.
Should persons experience nuisances,
they are
free to negotiate with the Village or bring an action before the
Board to resolve those issues,
57-475
10
Based on the foregoing,
the emission limit requested by the
Village of Winnetka is granted.
The Village’s modeling, which
considered Boilers Nos,
7 and
8 to be operating at full load,
adequately demonstrated that violations of the applicable stan-
dards will not result at an emission rate of 5.7 pounds per
million British thermal units of actual heat input.
In granting
the relaxed emission limit as a site specific rule for the Village
of ~7innetka’spower plant, the limitation shall be expressed as
a
mass emission limit.
This will eliminate use of a poorer quality
of fuel
at reduced loads which in turn could result in lower
plume heights and higher ground level pollutant concentrations.
At First Notice,
a limit of 3.2 percent sulfur content was proposed
for the coal burned by the Village.
Comments received from the
Agency indicated that
limiting the Coal’s sulfur content does
not correspondingly limit sulfur dioxide emission.
Therefore,
the
proposed sulfur content limitation has been eliminated.
On the
other hand, Agency comments requested that the methods for demon-
strating compliance be articulated in the rule,
Accordingly, the
rule has been written to require that compliance be based on
daily averages.
The rule,
as adopted, is
located at Subpart V of
Part 214, at Section 214.521.
This Opinion supports the Board Order adopted in this matter
this same day.
Board Member Bill Forcade abstained.
I,
Christan L. Moffett, Clerk of the Illinois Pollution
Control Board, do hereby certify that the above Opinion was
adopted on the
~q
day of
,
1984 by a vote of
Illinois
Pollution
Control Board
57-476
