ILLINOIS POLLUTION CONTROL BOARD

February

5,

1987

IN THE MATTER OF:

)

PROPOSAL OF MOBIL OIL CORPORATION

TO AMEND THE WATER POLLUTION

)

 R84—16

REGULATIONS

)

PROPOSED RULE.

 FIRST NOTICE.

PROPOSED OPINION AND ORDER OF THE BOARD

(by

 J.~ Marlin):

This matter comes before the

 Board upon the May

1,

1984

filing

of

 a proposal

 by Mobil Oil Corporation (Mobil)

 requesting

site—specific relief from the ammonia nitrogen effluent standard

(Section 304.122(b)).

 Relief

 is also requested from

the

requirement that

 no effluent shall cause

 a violation of a WQS

(Section 304.105)

as

 it concerns the general use ammonia nitrogen

water quality standard

 (WQS)

 (Section 302.212), the secondary

ammonia nitrogen WQS

 (Section 302.407), the general

 use dissolved

oxygen

 (DO) WQS

 (Section

 302..206)

 and the secondary DO WQS

(Section 302.405).

 Mobil discharges into the Des Plaines River.

Hearing was held

in

 Joliet,

 Will County,

 Illinois on

 July

26,

 1984.

 On October

 30 and December

13,

 1984,

 Mobil

 filed

responses

 to the written inquiries of the Illinois Department of

Energy and Natural Resources (DENR).

 The DENR concluded that an

economic impact

 study was unnecessary and filed its negative

declaration on February 22,

 1985..

 The Economic Technical

Advisory Committee agreed with this finding,

 filing

its

concurrence on March 12,

 1985.

 The last brief was filed on June

4,

 1985.

 The Board by Interim Order dated September

5,

 1985,

requested that the participants address

 the question of whether

the Board has authority

 to grant site—specific relief from 35

Ill.

 Adm. Code 304.105.

 On February

4,

 1986,

 the Agency moved

to

file USEPA comments, and on

 February

7,

 1986,

 Mobil

 filed

its

response

 to USEPA comments which contained amended proposed

language.

 Both motions were granted by a Hearing Officer on

Februrary

 24, 1986.

 The Agency on March

 20 filed its response

to

Mobil’s response and modified proposaL

 On April 10, 1986,

 Mobil

moved

 for leave

 to file its reply to the Agency’s response

to

the

modified proposal.

 That motion

 is granted..

 On July

7,

 1986,

 Mobil

 filed

 a motion for leave

 to file Comment

 in Opposition

to

Applicability of Central Illinois Public Service Company v.

PCB

to

 this cause.

 In the Agency’s response, filed on July 17,

 1986,

the Agency did not object to Mobil’s motion.

 Mobil’s motion

is

granted.

Mobil

 is currently operating under

 a variance from

 3 mg/l

ammonia nitrogen effluent standard of

35

 Ill.

 Adm. Code

304.122(b)

 until July

1,

1988

 or until

 final action

 is taken

in

75.295

this

matter,

whichever

occurs

first.

Under

this

variance,

the

ammonia

nitrogen

concentration

Mobil’s

discharge

must

not

exceed

monthly

average

concentration

mg/i

and

daily

maximum

mg/I.

Mobil

Oil

Company

v.

 Illinois Environmental

Protection

Agenç~y, PCB

86—45,

slip

Opinion

and

Order

(August

14,

1986).

Mobil

has

been

granted

five

variances

from

the

ammonia

nitrogen

standard:

PCB

77—22,

PCB

78—97,

PCB

80—54,

PCB

82—36

PCB

84—37.

Mobil

has

incorporated

reference

the

proceedings

the

five

variances

this

regulatory

proceeding.

(R.

114).

Mobil

owns

and

operates

conventional

fuels

petroleum

refinery with

 a rated capacity of 180,000 barrels per day located

in Joliet,

 Illinois in Will County.

 The refinery discharges 2.74

million gallons of effluent per day.

 Storrnwater, noncontact

cooling water

 and process water

 are discharged from the facility

into the Des Plaines River.

 The process water

 and contaminated

surface runoff

 (1600 gpm) are treated

 in Mobil’s wastewater

treatment plant

 (WWTP) which consists of an API separator,

a

dissolved

 air flotation unit,

 an equilization basin

 for primary

reatment and

 a conventional activated sludge facility

for

secondary treatment.

 Treated effluent from the final

 clarifier

routed

through

4.98

million

gallon

guard

basin

where

retained for approximately

hours

and

then

aerated

the

final

aeration cone prior

 to release

 to the Des Plaines River.

The

effluent meets all discharge standards other

 than ammonia

nitrogen.

 Mobil Oil Company, PCB 86—45 at 1—2.

Mobil

 is requesting that its effluent limits

for

 ammonia

nitrogen be set at

 25 mg/i

for

 a monthly average and 40 mg/l for

a daily maximum,

 (Pet. Brief,

p.

3).

In the past

 13 years,

 Mobil has expended considerable time

and effort

in

 its attempt to

 reach ultimate compliance with

the

ammonia standards.

 The total cost of ammonia related capital

expenditures

is

 in excess of $2.1 million.

 The average annual

operating cost

for

 ammonia reduction projects during the last

five years has been $1,801,000,

 including amortization of capital

investments.

 Equalization system improvements and continuous

dissolved oxygen monitoring

 in the aeration basins cost

an

 additional $64,000 between 1982 and 1985.

 Projects have included

the purchase and installation of

 a nitrification pilot plant,

nitrification inhibition studies, mutant bacteria

 trials,

alkalinity addition and temperature control

in

 the aeration

basins.

 Since

 1973, these efforts have reduced Mobi8l’s

discharged ammonia concentration by

 96 percent (Id).

 Mobil Oil

Company, PCB 86—45,

at

2.

Mobil

 investigated six alternative nitrification

technolog

ies.

Three

 biological systems

 (activated sludge,

trickling

 filter

 and rotating biological

 contactor) were rejected

because of their inability

 to consistently achieve the ammonia

nitrogen effluent standard of

 3 mg/l

(R.

 97—B, See Pet.

 Exh.

2,

p.

59,

 60).

 Three chemical processes were also addressed.

75-296

3

Breakpoint chlorination and ion exchange processes would

consistently meet the

 3 mg/i standard

(R.

 94—5).

 However,

breakpoint chlorination was not recommended because of the

formation and release of toxic chlorinated byproducts

(R.

 94).

The ion exchange process would entail

 a 7—8 million dollar

capital

cost

with

$450,000

annual

operating

cost,

plus

added

cost

for

activated

carbon

treatment

organic

fouling

occurred

(R.

 95).

The

third

chemical

process,

ammonia

stripping,

would

not enable Mobil

 to reduce its effluent concentration enought

to

achieve the

 3 mg/i standard.

 In addition,

 it has relatively high

capital and operating

 costs as well

 as potential operational

problems.

(R.

 96).

 After assessing the available control

alternatives,

 an expert witness for Mobil concluded

 that absolute

compliance with the

 3 mg/i standard could only be achieved by the

ion exchange process.

 He stated that “in

 the absence of

a

beneficial

 influence on receiving water quality,

it

 is difficult

to recommend the expenditure of several million dollars

to

achieve further reduction

 in effluent ammonia at the Joliet

refinery.”

(R.

 103).

Environmental Impact

Water quality standards

 for ammonia nitrogen and dissolved

oxygen are being exceeded

 in the Des Plaines

 River at the point

of Mobil’s discharge,

 river mile

 278.

(R.

 157—8).

 Mobil

 asserts,

and the Agency agrees,

 that the condition of the river

is

primarily due

to

 the discharges of three Metropolitan Sanitary

District of Greater Chicago (MSDGC)

 sewage treatment plants

located

 upstream of Mobil.

 (Pet.

 Brief, p.

 6—7; Ag. Brief,

p.

3).

 Based

 on an annual average, calculated from data taken from

July,

 1982 through December

31,

 1983, Mobil’s discharge

constitutes 0.3 percent of the river’s total

 point source loading

of ammonia nitrogen.

(R.

 139)..

 Th MSDGC sewage

 treatment plant

discharges make

up

 96 percent of the ammonia nitrogen loading.

(Pet. Exh.

#7,

 p. 8).

The Agency concurs with Mobil that Mobil’s current

discharges of ammonia nitrogen have

 “rio significant environmental

impact.”

 The Agency states that “continued discharges by Mobil

at its present rate and concentration will have no discernible

effect upon

 the biota

 in the lower Des Plaines and upper Illinois

Rivers.”

 (Ag. Brief, p. 3).

In addition, the nearest actual

 or proposed public water

supply downstream of Mobil’s outfall is the City of Peoria which

is 110 river miles away.

 Because of the distance and

the

relative amount of the discharge,

 a witness

for

 Mobil stated that

the ammonia nitrogen added

 by Mobil would have “appreciable time

for degradation” by the

 time it reaches Peoria.

(R.

 182).

Economic Impact

An expert witness

 of Mobil

 stated that

 if the lower Des

Plaines and upper

 Illinois rivers

 improved greatly

 in quality

75.297

such

that

would

become

combined

sport

and

commercial

fishery,

its

value

would

 $51,633 per mile per year.

(R.

187).

Mobil

discharged

MCD

mg/i

into

the

river

during

a seven—day, ten—year low flow of

1186

MGD,

the

river’s

concentration of ammonia nitrogen would

 rise by 0.101 mg/i near

the discharge point.

(R.

 145—6),

 The river would flow

approximately 1.85 miles before the added concentration of

ammonia nitrogen would be completely nitrified.

(R.

 187).

If

it

is assumed

 that a 0.101 mg/i increase

 in ammonia nitrogen would

completely destroy the value of the river’s potential

 in being

a

sport and commercial fishery,

 the impact would equate

to

 a loss

of $95,521 per year.

 When figuring Mobil’s relative contribution

to

 an overall 1.6 mg/i river concentration, the monetary loss

directly attributable

 to Mobil would be $6,448 per

 year~.. (R.

188)

 It was estimated

 that if Mobil

 is granted relief,

 it would

save, at the minimum, $420,000 per year.

 Based upon these

assumptions,

 the ratio of Mobil’s savings

 to society’s cost would

be

65

to

1.

(R.

 189—90).

It

 is Mobil’s position that

a

treatment plant expansion, required

 to achieve compliance with

the existing

 standard is not economically justified.

 (Pet. Brief,

p. 10).

 The Agency concurs with Mobil

 that “the ratio

 of likely

cost expansion

 to likely beneficial impact would be extremely

high,

 and thus economically unjustified.”

 (Ag.

 Brief, p.

4).

The DENR concluded that the “cost of making

a

 formal study

is economically unreasonable

 in relation

to

 the value of the

study

 to the Board

 in determining the adverse economic impacts of

the regulation.”

 (DENR Negative Declaration,

p.

2).

Consequently,

 it issued

 a negative declaration

 in this matter.

Ammonia Nitrogen Limitations

Mobil

 requested that

 the Board

 set limitations of

a

 25 mg/i

monthly average and a

 40 mg/i daily maximum.

 These limitations

were determined by evaluating

 the historical performance data of

the WWTP.

 According

 to Mobil, these limits are necessary to

account

 for fluctuations

in

 the effluent concentrations.

 Studies

indicate that the WWTP consistently removes

a

17

 ing/l

 increment

from the WWTP influent.

 Consequently, Mobil concludes that the

effluent fluctuations are due

 to higher crude nitrogen and

production levels.

Due

 to these variations, Mobil states that

the requested limitations are necessary to “insure consistent

compliance.”

 (Pet. Reply,

p.

6).

Pursuant to

 a Hearing Officer

 Order dated August

13,

1985

in

this proceeding

 and the variance conditions of PCB 86—45, Mobil

has submitted bi—monthly reports which cover effluent data from

January,

1983

 to December,

 1986.

 The data from these bi—monthly

reports

 can be

 summarized as

 follows:

75-298

AMMONIA NITROGEN CONCENTRATIONS

 (MG/L)

Yearly Avg. of

 Highest Monthly

 Highest Daily

Year

 the Monthly Avg’s.

 Avg.

 Maximum

1983

 4.35

15

27

1984

 2.58

8

19

1985

3.33

1986

4.00

The Board recognizes that

1973

Mobil’s

discharge

averaged

77 mg/i and that

 in 1979 and 1980,

 it averaged

 i3 and 17 mg/i

respectively.

 Mobil Oil Company, PCB 86—45

at

2.

 However, data

from the past four

 years indicates that Mobil’s actual

performance level, when calculated

 on an annual average,

 is quite

close

 to the

 3 mg/i standard.

The Board finds that if Mobil

 is granted relief,

the

resulting environmental and economic impact would be minimal.

Considering the available alternatives for Mobil, compliance with

the

 3 mg/i

 standard, although technically feasible, would be

economically unreasonable given Mobil’s current performance

levels.

 Consequently, the Board will grant Mobil relief from

Section 304.122(b).

The Agency is concerned that if the Board grants Mobil

the

limits that

 it is requesting,

 Mobil may relax

 its present control

methods thereby increasing

 the ammonia nitrogen concentration

in

its discharge.

 The Agency proposed

a

 10 mg/i monthly average,

a

30 mg/i daily maximum, and

a

 5 rng/l annual

 average..

 The Board

shares the Agency’s concern

 in light of the fact that limits

requested by Mobil

 are considerably higher

 (sometimes by a factor

of two)

 than its actual discharge.

 Consequently, the Board will

require that Mobil’s discharge not exceed the following

limitations:

 monthly average, 20 mg/i;

 daily composite,

 35 mg/l;

and and yearly average,

 B mg/l.

 The daily composite limit

 is set

to allow Mobil

 the day to day fluctuations of effluent

concentrations that it periodically experiences.

 The monthly

average

limit

set

account

for

the

impact

that

these

daily

fluctuations

have

upon

monthly

average

calculation.

The

Board

believes

that

this

objective

can

fully

achieved

mg/i

standard and that the monthly standard proposed by Mobil

is

unnecessarily high.

 The Board understands that Mobil experiences

periodic losses

 of nitrification.

 However, Mobil’s present

levels of performance, including its variations, are well within

these limitations.

 The yearly average of

 B mg/i will allow for

considerable deviation

 from current performance due

to

anticipated problems and varying

 feedstocks without allowing

Mobil

 to significantly decrease its control efforts.

75.299

Mobil has asserted that an

 increase

 in the nitrogen content

of the crude oil

 it refines correspondingly increases its

effluent concentration.

 In particular,

 it claims that nitrogen

content of the crudes have increased over the years.

 The crude

oil nitrogen content at the Joliet refinery has gone from

 a low

of about 680 parts

 per million

 (ppm)

 in 1976

 to a high of about

1450 ppm

 in 1984.

In

 1985,

 it dropped

to

 a level

 of 1120 ppm.

Mobil

 Oil Company,

 PCB 86—45 at

3.

 If Mobil finds in the future

that

 it exceeds the standards on

 a regular basis,

 it can come

before the Board under

 another docket

 to seek relief.

 However,

 even though

 in recent years Mobil’s crude feedstocks have had

a

high nitrgoen content,

 its effluent has been within the limits

set herein.

The methodology for computing the annual average shall be

determined during the permit process.

It

 is expected that if

a

differing

 number of samples are gathered

 from different months

then the results of these samples should be weighted accordingly

so

as

 to yield

 a reasonably accurate annual average.

 Mobil will

be required

 to monitor and report its effluent concentration.

However, procedures

 for monitoring

 and reporting effluent

concentrations, will also be set

 forth

 in the permit.

 Mobil will

be required

 to report on an annual basis

 the nitrogen content of

its feedstock.

Water Quality Standard Relief

Mobil has also requested relief from being

 liable

for

causing the violation of various water

 quality standards (WQS).

In response to

 a U.S. Environmental Protection Agency

 (USEPA)

Review Statement submitted by the Agency, Mobil modified its

original proposed

 language addressing

 the water quality standards

issue.

 Essentially, the modified language states that 35 Ill.

Adm. Code 304.105 will apply to Mobil with respect to general

use

and secondary contact WOS for ammonia nitrogen and dissolved

 oxygen,

 “unless such discharge does not cause or contribute

significantly

 to the violation”

 of the WOS.

 (Mobil Response,

p.

1).

 Mobil’s discharge

 is located approximately 200 feet upstream

of the 1-55 bridge.

 The river upstream of the bridge

is

classified

 as secondary contact, whereas downstream of the

bridge,

 the river

 is considered general use.

(R.

 125—26).

Consequently, Mobil’s discharge may,

 in theory,

 impact upon both

secondary contact and general use

 streams..

The general use water quality standard for total ammonia

nitrogen, given the river’s

and

temperature,

1.5

mg/i

(35

Ill.

 Adrn.

 Code 302.212).

 The general use water quality standard

for dissolved oxygen is

 6 mg/i

 (35 Ill. Adm. Code 302.206).

Mobil’s impact upon

 these standards

 is discussed in Petitioner’s

Exhibit

3,

 a report prepared by an expert witness

 for Mobil.

The report shows that the general use standard

 for ammonia

nitrogen

 is exceeded downstream of Mobil’s discharge.

 However,

it

 is concluded that under

 worst

 case conditions

 (Mobil

75-300

discharging

 3 MGD at 40 mg/i into

 the river

 flowing at

 a low

level of

 1,186 MGD),

 Mobil’s discharge would extend by only 1.85

miles

 the reach of the river which did not meet the

 ammonia

nitrogen standards

 (Pet.

 Exh.

#3,

 p. 16).

Similarly,

 the dissolved oxygen standard

 is exceeded

downstream of Mobil.

 However,

 under

 the same worst case

conditions, Mobil’s discharge would not extend by more than one

mile the reach of the river which did not meet the dissolved

oxygen standard.

 (Id.

at

 19).

The secondary contact ammonia nitrogen standard

 is 2.5 mg/i

(35 Ill.

 Adin..

 Code 302.407).

 It is apparent from data reported

in Petitioners Exhibit #3

 that this standard

 is exceeded upstream

of Mobil’s discharge.

 (Pet.

 Exh.

#3,

p.

 17).

The secondary contact standard for dissolved oxygen

is

4

mg/i

 (35 Ill.

 Adin..

 Code 302.405).

 Data shows that this standard

is exceeded

 in the river mile where Mobil discharges.

 (Pet..

 Exh.

#3,

p.

 18).

 Consequently,

 it is likely, given the upstream

exceedences of the ammonia nitrogen standard, that the dissolved

oxygen standard

 is also being violated upstream of Mobil’s

discharge point.

In

 the USEPA’s Review Statement,

 the USEPA stated that

Mobil’s addition

 to the river is “insignificant” with respect

to

water quality violations.

 It concluded:

Mobil

 should

not

be

 granted

 relief

 from

Section

 304.105

but

 should

be

 required

in

their NPDES permit

to,

 in addition to standard

effluent

 monitoring,

 conduct

 upstream

and

downstream

 ammonia—N

 monitoring

at

representative

 sampling

 points

to

 clearly

ascertain whether

or

 not they are responsible

for

 water

 quality

 standards

 violations

for

ammonia—N.

The Board agrees and finds that Mobil’s current impact on water

quality is de inininius.

 Consequently, the Board will

 not grant

Mobil

 relief from Sectio~n304.105.

 The Board

 notes that its

determination that Mobil’s discharge is de minimus only applies

to the present situation.

 Should conditT6ns

in

 the river change,

Mobil’s discharge might cause WQS violations

in

 the future.

The

Board also believes that

 the instrearn monitoring,

 as proposed by

the USEPA,

is

 a requirement suitable for consideration by the

Agency as

 a permit condition.

Finally,

it

 is the Board’s position that the record supports

the granting

 of permanent relief

 from the ammonia nitrogen

effluent standard..

In

 re Union Oil Company of California,

R 84—13, January

8,

 1987,

 the Board

 also granted Union Oil relief

from

 the ammonia nitrogen effluent

 standard with regard

to

its

Lemont Refinery.

 However,

 the Board limited the relief

 to seven

75-301

years.

 Such

 a “sunset provision”, though,

 is not necessary in

this matter.

The data shows that Mobil, unlike Union, has largely been

successful

 in reducing the concentration of ammonia nitrogen in

its discharge.

 The Board notes that on an annual

 average Mobil’s

discharge has been quite

 close to the

 3 mg/i

 standard..

 This

is

true even

 in recent years when the nitrogen content of the oil

feedstocks have been high.

 The Board fully expects Mobil

to

continue

its

high

performance

level

concerning

ammonia

nitrogen

 concentrations.

 The Board, therefore,

 grants Mobil permanent

relief from Section 304.122(b) within

 the conditions listed

in

the Order.

ORDER

The Board hereby proposes to adopt

 the following

 rule and

instructs the Clerk of the Board

 to cause

 its publication

for

First Notice

in

 the Illinois Register:

TITLE 35:

 ENVIRONMENTAL PROTECTION

SUBTITLE

C:

 WATER POLLUTION

CHAPTER

I:

 POLLUTION CONTROL BOARD

PART

304

EFFLUENT STANDARDS

SUBPART

B:

 SITE—SPECIFIC RULES AND

EXCEPTIONS NOT OF GENERAL APPLICABILITY

Section 304.214

 Mobil Oil Refinery Ammonia Discharge

a)

 This Section applies

 to discharges from Mobil Oil

Corporation’s Refinery, located near Joliet,

 into the

Des Plaines River.

b)

 The requirements of Section 304.122(b)

 shall not apply

to the discharge.

 Instead Mobil’s discharge shall

not

exceed

 the following limitations:

CONSTITUENT

 CONCENTRATION (mg/i)

Ammonia Nitrogen

Monthly Average

20

Daily

Composite

Yearly

Average

 Section 304.104(a)

 shall not apply to this Section.

Monthly average and daily composites are

 as defined

in

Section 304.104(b).

75-302

d)

 Mobil

 shall monitor

 the nitrogen concentration of its

oil feedstocks

 and report on an annual basis such

concentrations to the Agency.

 The report shall

 be filed

with the Agency by January

 31 of each year.

(Source:

 Added

at

 11 Ill. Reg.

____________________

effective

_____________________)

ORDERED..

Dorothy

Gunn,

Clerk

the

Illinois

Pollution

Control

Board, hereby certify that the above Pr~.oposedOpinion and Order

was adopted on the

.~-

day

1987,

vote of _________________________.

~

)2?.

Dorothy

 M. Cunn,

 Clerk

Illinois Pollution Control

 Board

75-303