ILLINOIS POLLUTION CONTROL BOARD
December 29,
1983
IN THE MATTER OF~
SULFUR DIOXIDE EMISSION
)
R80—22(B)
LIMITATIONS; VILLAGE OF WINNETKA
FIRST NOTICE.
PROPOSED OPINION.
OPINION OF THE BOARD
(by J.
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 (V~1—
lage)
sought to include
a site specific rule so that its utiTity
plant could emit up to 5.7 lbs/mBtu of sulfur dioxide.
A dr.~&ft
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-
specific limitation
for two reasons.
Although the Village
had participated in the rulemaking,
it was not until hearing;
in June of 1982 that the specifics and the supporting evidence
of the Villag&s
request became known.
The Board reasoned that
this did not provide sufficient
time for notice
to or respon~e
from concerned public,
Secondly,
the draft rules in R80—22
included an adjudicatory format for existing individual
sources to
seek relaxed,
alternative
limits.
In 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 October
8,
1982 the request was
granted
and the sublect
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
DockeL
B.
When the proposed rules
(Docket
A) were adopted as
final on February 24,
1983, the Village~sutility plant was
exempLed from the 1.8 lbs/mBtu limit pending the outcome of
Docket
B.
This Opinion principally pertains to Docket
B.
After separating
the Villag&s request from the whole of
R80-22 two more hearings were held
in Winnetka on November
3
55-473
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.
Where Tower Road meets Lake Michigan in Winnetka, the
Village owns and operates a electrical generating plant which
supplies the power needs
for the Villag&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.
Both diesels were
ir.stalled
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).
To demonstrate that Illinois coal of this quality could be
burned at its power plant,
withoW:. 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 con—
55-474
3
centrations,
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
requirements,
processing
techniques
and, input/output formats were
modified
to
develop
a
non-guideline,
Case
1
mode.,
The principle
variation
was
premising
the
atnospheric
stability
data
on
meteorological
data from the Zion nuc:lear power
plant,
23
miles
to the north,
as opposed to that from Midway and O’Hare Airport
which
are
eight
and
twelve
miles
inlarid~
respectively.
The Zion
meteorological
data
satisfies
the
federal
requirements
(10
CFR
50,
App.
B),
but
the
CRSTER
model
had
to
be
modified
to
accommodate
this
more
representative
lakefront
information.
Mixing
heights
were
specifically
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~’tworadials.
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 be
identified
and assessed against the applicable air quality stan-
dards.
The modeling program
included
certain constants.
The
stack’s diameter was set at three meters,
the
temperature at 350°
F,
(or
375°
F
for
the
full
load
model)
and
its
height
at
57
meters.
At
this
height
the
stack
:Ls
considered
consistent
with
good
engineering
practice,
that
is,
high
enough
above
the
plant’s
roof
and
other
obstructions
to
avoid
interference
or
induced
turbulence.
Rural
dispersion
coefficients
were used instead of
urban coefficients.
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
4
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 cperating
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
_____
____
(SOug/m
)
(365ug/m
)
(l300ug/m
Orient
1.fl
11,780 Btu/lb
Actual
2
69
318
No. 3
Full
2
71
361
Fidelity
3.19
11,054 flu/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).
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
55-476
5
Coal
Modeled
Measured
Sum
Standard
Fidelity
Annual
4
25
29
80
411
24—Hour
133
165
298
365
3—Hour
610
291
901
1300
In proposing the 1.8 lbslmfltu 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.
(R.
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 mo4el to verify that it was
conservative.
It used the guidelines recommended in the CRSTER
model and maximum load at 5.7 ibs/atu 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 lodel 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
3 (ug/m3)
Village
Agency
Village
Agency
Standard
Highest
Highest
Background
Background
Background
Annual
(80ug/m3~
4
5.6
25
29
31
24
Hour
(365ug/m3)
133
66
165
298
231
3
Hour
(l300ug/m3)
610
315
291
901
606
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/mBtu limit and still
utilize Illinois coal.
Installation of
wet scrubbers
was
55-477
6
estimated to
necessitate
capital
expenciltures
of
$3~.2million
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~
(R
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
piant~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
Villag&s
engineers
also
noted
that
increased
exit
speed
will
not
affect
final
plume
rise
because
it
;Ls
a
function
of
volumetric
flow,
~q~u~c,b
~
)T
,i
~r
tr’~
t
oTnm~r1
~
The Economin impact
Stnoy prepared by tte bepartmtint
of
Energy
and Natural
Resources did not sec ifinal 1.y consider the
Winnetka
facility and
•the economic ramifications should it
be
allowed
to
burn
I I
inois
h:Lqher
sul fur
coal
The
VU lage
did
provide
numerous
details.,
From
1958
until
i975 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
vil1age~s operating
expenses,
(F.
976)
The
net
worth
of
the
plant
was
$3, 710,000
:in
1957,
$8,6l3~0OO
in
1975 and
$11,000,000
in
1982.,
Improvements
at
the
plant
were paid
for out
of
earnings.
Before
1971,
the
plant
produced
all
of
the
Village~senergy
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. l~ per
kw/hr
in
the
late
1970~s
and
early
i980~s the
vil:Laqe
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
nowe :r
costs
from
Commonwealth
Edison.
Since
burning
Illinois
coal
under
the
Agency
issued
permits
the
Village
has
been
producing
over
90
percent
of
its
energy
demands
and
purchasing
on:Iy
economy
power
from
Commonwealth
Edison
In
addition
to
the
lower
power
costs
and
revenue
generated
which
aid
its
residents,
the
Vii
:Laqe.
claimed
socio—economic
bene-
fits
due
to
its
plant’s
operation
on
Illinois
coal.
The
Village
is
committed
to
using
I1Iii~ois
coal
and
although
it
will
not
purchase
large
amounts
of
it,
some
increased
economic
activity
should
be
generated
in
Illinois.
The Viliag&s
plant
employs
18
persons.
Finally,
the Village
anticipates
that
it
will
be
able
to
provide
its
residents
with
power
when
other
areas
are
53~4?8
experiencing power outages~
Several
examples
oE
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~
lags.
The
review
was
three
part:
(1)
a discussion of
the
coast~
al
meteorological adversely affecting pollutant dispersion;
(2)
the inapplicability of the Villag&s model and the underlying
CRSTER
model
in assessing the Villag&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 circuladon,
CBE
acknowledged that the Village’s use of meteorological
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,
CBS argued was
for low emission sources such as
nuclear reactors,
not stacks at fossil fuel plants.
CEE
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
55~479
argued that these would have been preferable.
Finally, CBE
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.
(R.
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 consi.dered 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
i..hese
assumptions
make
the
model more conservative.
(R.
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 he 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 CBS’s review,~theAgency 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
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—
9
rological
data
was
used,
a
site
specific
model
is
unwarranted.
The
Board having reviewed the testimony and comments on the
modeling
format
and
the
results,
concludes
that
the
ambient
air
quality
standards
for
sulfur
dioxide
are
not
violated
and
an
adequate
margin
of
safety
for
health
and
growth
is
preas~rved.
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 Winnetka 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.
(R.
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
inforina—
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.
In granting the relaxed emission limit as a site specific
rule for the Village of Winnetka’s power plant, the limitation
shall be expressed as a
mass emission
limit.
This will eliminate
use of a poorer quality of fuel at reduced
1.oads which in turn
could result in lower plume heights and higher ground level
pollutant concentrations
•
The Village’s
modeling
which consid-
ered Nos.
7 and 8 Boilers to be operating at full load adequately
demonstrated that violations of the applicable standards will
not
55-481
10
result at an emission rate of
5.7
pounds
per
million
British
thermal units of actual heat input.
This Opinion supports the Board Order of December 1, 1983.
Board Member Bill Forcade abstained.
,
Christan L.
Moffett, Clerk of the Illinois Pollution
Control Board, do ~j~eby cert’ fy that the above Opinion was
a~oPtedon the
A’1
_day
of
,
1983 by a vote of
55-482
