ILLINOIS POLLUTION CONTROL BOARD
January
16, 1975
MOBIL OIL CORPORATION,
Petitioner,
v.
)
PCB 74—393
ENVIRONMENTAL PROTECTION AGENCY,
Respondent.
OPINION
AND
ORDER OF THE
BOARD
(by Dr. Odell)
On October 29, 1974, Mobil Oil Corporation filed its
Petition for Variance with the Pollution Control Board
(Board).
Mobil Oil sought a one-year extension of the variance granted
in Mobil Oil Corporation v. Environmental Protection Agency
PCB 73—452,
13 PCB 179
(July
25, 1974).
In that case,
this
facility was granted
a six—month variance subject to certain
conditions
from Rule 408(a)
of the Water Pollution Regulations
(Chapter Three)
for cyanide discharges into the Des Plaines River.
Here the Petitioner also sought a variance from Rule
1002 of
Chapter Three, which relates to the filing of
a project completion
schedule with the Environmental Protection Agency
(Agency).
Mobile owns and operates a petroleum refinery in Will
County, near Joliet on Interstate
55.
Cyanide is formed in the
refinery fluid catalytic cracking unit
(FCC). High temperatures
“crack”,
or break down the large molecules into smaller ones.
It
is estimated that 90
of the cyanide formed comes from the crack-
ing unit;
the other 10
is formed in the coker unit.
Cyanide
enters the waste water system when FCC pipes are washed to remove
accumulated salt deposits.
80
of the cyanide is removed at the
sour water stripper.
A total of
2.6 mgd of wastewater is released
into the Des Plaines River.
The refinery processes 175,000 barrels
of oil per day into liquid petroleum
gas,
motor gasolines,
jet and
diesel fuel,
heating oils,
and coke.
Initial sampling in February 1973 of refinery effluent show-
ed
a cyanide concentration of 1.30 mg/l.
Rule 408(a)
sets a limit
for cynanide discharge at 0.025 mg/l. While Mobil Oil felt that un-
sophisticated sampling procedures were responsible for the high
discharge concentration,
it nevertheless admitted that its
effluent exceeded the cyanide standard under Rule 408(a).
Oil refinery cyanide discharge problems are not unique to
Mobil Oil’s Joliet refinery.
Similar variance requests have been
made in the past by other Illinois refineries.
The list of these
variance cases includes Texaco Oil Company
v. Environmental
Protection Agency PCB 73-6,
8 PCB 537
(July
19, l973Y where the
variance was denied; Union Oil Company v. Environmental Protection
?CB 72-447,
10 PCB 217
(December
6,
1973) where the variance
15.— 253
—2—
was granted and later extended in ?CB 74-333,
14 PCB
_______
(December
5,
1974); Clark Oil Company
v. Environmental Pro-
tection Agency PCB 73-238,
9 PCB 449
(October 11,
1973)
where
the variance was granted, but an extension for cyanide was later
denied in PCB 74-283,
14 PCB
_______
(October 31, 1974).
As we
noted in granting PCB 73-452, several factors contribute to the
need for variances by oil refineries for cyanide discharges:
“1.
Recent water conservation measures by refineries are
largely responsible for increased cyanide concentrations in re-
finery effluents.
“2.
Cyanide in refinery wastewater
is not amenable to
traditional cyanide treatment
(e.g.,
alkaline chlorination process)
because of the presence of relatively stable inorganic
arid organic
cyanide complexes in addition to the existence of excessive oxidiz-
able substances
(e.g., ammonia and residual organic matter not
removed in secondary wastewater treatment).
“3.
Methods for reducing refinery cyanide problems are
still in the research stage.”
In granting PCB 73-452, we made the Order subject to the
following conditions:
“1.
Petitioner’s cyanide effluent concentration shall
not exceed
a monthly average of 0.5 mg/l during the period of this
variance.
“2.
At no time shall Petitioner’s effluent exceed 0.8
mg/l cyanide.
“3.
Petitioner shall utilize any methods it may find use-
ful to keep its effluent at the lowest possible cyanide level.
“4.
Petitioner shall continue to diligently pursue its
program of research and development in regards to cyanide reduction.
“5.
Petitioner shall, starting in
30 days after the entry
of this Order,
file with the Agency bi—monthly reports.
Said reports
shall include, but not be limited to:
(a)
Progress on all methods being pursued by Petitioner
regarding cyanide reduction.
(b)
Future work anticipated or methods being pursued
by Petitioner.
(c)
Any and all records of cyanide concentration in
Petitioner’s effluent.
At least
one
determination
of cyanide shall be run per week.
(d)
What methods
if any are being used to comply with
(3)
of this Order.
15
—
254
“6.
As
soon
as
a
technologically
feasible
program
for
cyanide
reduction
has
been
found?
Petitioner
shall
commence
on
a
compliance plan to implement
tbis
program.”
Effluent cyanide
levels
for
~4ob•i1
Oil
Ear
January
through
October 1974 indicate that,
except
for
Marc~h
28,
1974,
conditions
I and
2 of the Board~sOrder
in
PCB
73-~452have been complied with:
Monthly Average
Effluent
Cyanide
Levels
Month
Total
cyanide
Simple
cyanide
Simple cyanide
1974
mg/i
-_____
mg,/IL
of total
January
0,182
February
0.276
0.061
22.1
March
0,49
*
0.08
16.3
April
0,17
0.03
17.6
May
0.10
0.10
100.0
June
0,18
0.08
61,1
July
0.09
0,11
122.2
August
0.074
0.086
116.2
September
0.078
0,059
75.6
October
0.302
0.223
73.8
*
This
unusually
high
average
is due primarily to
one high analysis
(0.96)
for a sample taken on
March
28.
If results from this analysis are
omitted the average for March would be 0.33.
Tests are continuing
at Mobil Oil on several control methods
discussed in PCB 73-452:
1.
Parson’s HCN Destruction Process:
additional
tests to be run.
2.
Procon’s Cyanide Removal Method:
method abandoned.
3.
Ultraviolet Radiation:
more extensive tests
possible.
4.
Powdered Activated Carbon:
bench scale studies
slated for January 1975.
5.
FCC Process Improvements:
addition of
steam
to
FCC feed has shown cyanide reduction.
New methods of cyanide control now being investigated by
Mobil Oil include FCC Sour Water Stripping and Sulfating of
Cyanides.
In the first procedure,
tests will be made to determine
the feasibility of segregating the cyanide-bearing FCC stream and
stripping
(removing the cyanide)
this stream independently in
a
is
—
255
—4—
small stripper.
The sulfate procedure involved methods of con-
verting CN
to other less toxic compounds by contact with ele-
mental sulfur to form thiocyanate.
Also included in the Variance Petition
-
as required in
PCB 73—452
-
were data on water quality standards
at the edge of
the refinery effluent mixing zone.
Mixing zone samples obtained
on August 30,
1974, and again on October
4,
1974, contained 0.021
mg/i and 0.067 mg/i of cyanide, respectively.
During the second
sampling, a cyanide sample was obtained from the center of the
river upstream of the refinery as a reference for the mixing zone
analyses.
Analyses of this upstream sample indicated 0.065 mg/i
cyanide, but this seems questionable if it was properly sampled
unless there is cyanide pollution upstream.
Future samples at
Petitioner’s mixing zone and upstream should be taken carefully
to insure that they are representative.
Mobil Oil proposes to
continue to sample the refinery mixing zone every two to three
weeks to comply with the Board’s Opinion and Order, but question-
ed the value of continued testing because the total cyanide test
method specified in the regulation
(Storet No. 00720)
is only
sensitive to levels of 0.02 mg/i.
The Agency filed its Recommendation on December 16,
1974.
Exhibit A
(by Dr. M.J. Carter, US EPA)
,
which accompanied the
Agency Recommendation,
indicates that Mobil Oil cyanide testing
results during early 1974 were two to three times
less precise
than they should have been and, therefore,
they can and should
be improved.
The Agency recommended that the variance from Rule
408(a)
be granted for one year subject to certain conditions,
including lower cyanide effluent concentrations, continued re-
duction efforts to meet the standards,
and the continued filing
of reports.
The Agency “believes that Petitioner does possess
the requisite hardship to warrant an extension of its original
variance, provided certain conditions are met.
The essence of
Petitioner’s hardship, which existed at the time of its original
petition, and which continues to the present,
is that no techno-
logically feasible method has been found which enables cyanide
concentration levels to be accurately measured in the sub—parts
per million ranges;
nor, has any technologically feasible method
been discovered which would permit the reduction of cyanide levels
down to the prescribed 0.025 mg/i.
.
.
.
The Agency still believes,
however, that the results of Petitioner’s tests, conducted over a
ten month period,
so clearly indicate that Petitioner
is able to
meet requirements more stringent than a monthly average of 0.5
mg/i, with a 0.8 mg/I excursion,
that to permit continuation
of
these interim cyanide levels might cause Petitioner
to become
less active in its efforts to resolve
its cyanide problem.
The
Agency feels that by setting the interim cyanide level at 0.3
mg/i, with an excursion of 0.5 mg/i Petitioner will be both pro-
tected from an enforcement proceeding, and motivated to continue
its research programs.
.
.
.
The Agency believes that Mobil has
15
—
256
—5—
made good faith efforts at eliminating its cyanide effluent
problems; the Agency further believes that continuation of these
efforts must be a condition of an extension of Mobil’s variance,”
The impact of the continued discharge of cyanide from
the Mobil Oil Refinery on the receiving stream, the Des Plaines
River,
is difficult to assess.
According to the Agency, the
threshold limit of toxicity at infinite time for fish appears
to be 0.1 mg/i as CN
(Reference “Standard Methods”, APHA,
AWWA, WPCF,
1971),
More information is needed on the cyanide
compounds present, and their toxicity levels,
Considering the
dilution effect of the Des Plaines River
(275 to 1), the con-
centrations in the river should not exceed the water quality
standard of
.025 mg/i.
We grant the variance subject to terms and conditions
suggested by the Agency.
This variance will not necessitate
compliance with Rule 408 (a); we believe that the Petitioner has
established that control technology
is not yet available.
By
setting lower cyanide effluent limits than in PCB 73-452, we are
encouraging continued research and development and also limiting
the environmental impact of the discharges.
In light of all the
facts,
including Mobil Oil’s good faith efforts to achieve com-
pliance,
it would create unreasonable hardship to deny the
variance in this case.
This Opinion constitutes the findings of fact and con-
clusions of law of the Board,
ORDER
IT
IS THE ORDER of the Pollution Control Board that
Mobil Oil Corporation is hereby granted a Variance from Rule 408(a)
for cyanide only and from Rule 1002 of Chapter Three for one year
from January 25,
1975, through January
24,
1976,
subject to the
following conditions:
(a)
Petitioner’s cyanide effluent concentration shall
not exceed a monthly average of 0.3 mg/i or
a maximum of 0.5 mg/i
at any time, during the period of this Variance,
(b) The Petitioner shall continue its efforts of develop-
ing a cyanide effluent control program to reduce the cyanide
concentration
to
0.025
mg/i.
(c)
The Petitioner shall continue to file bi-monthly
progress
reports
with
the
Agency,
said
reports
to
include
but
not
limited to:
1.
Progress
in all methods being pursued by Petitioner;
2.
Any and all records of cyanide concentration in the
Petitioner’s effluent;
at least four determinations
shall be run per week;
15—257
—6—
3.
Any and all records of cyanide concentrations
at the edge of the mixing zone and upstream;
at least one determination at the mixing zone
and upstream shall be made per week;
and
At least one study shall be made during each
bi-monthiy period of reporting indicating the
characteristics of the cyanide wastes, including
the relative percentage of flow of dissociated
toxic ions, moderately complexed cyanide
ions
that are amenable to alkaline chlorination,
highly complexed cyanide ions that are not
amenable to alkaline chlorination destruction,
and cyanide ions associated with organic
corn—
paunds.
(d)
A3 soon as a technically feasible program for meeting
~
level of 0.025 mg/i of cyanide
is developed,
Petitioner
shall commence or~ a compliance plan to implement this program.
I, Christan L. Moffett, Clerk of the Illinois Pollution Control
Board, hereby certif
that the above Opinion and Order was adopted
on the
/Yh’k
day of
_______________,
1975,
by a vote of
to
W~4ae
Christan L~~~fett