ILLINOIS POLLUTION CONTROL BOARD

February

1996

IBP,NC.,

)

Petitioner,

)

PCB93-179

)

(Permit Appeal

NPDES)

)

ILLINOIS ENVIRONMENTAL

)

PROTECTION AGENCY,

)

Respondent.

)

DISSENTiNG OPINION (by C.A.

Manning and M. McFawn):

We respectfully

dissent.

We do not believe that petitioners havejustified the use ofthe

1,808

mg/I value as the permit level for their sulfate discharge.

The Illinois Environmental

Protection Agency’s (Agency)

permitting decision is supported by its technical

analysis ofthe data

submitted

in IBP’s permit application,

and that decision should not be disturbed.

The majority

opinion discounts technical

analysis in favor ofcommon sense inference, and

reaches a conclusion

which is not technically supportable.

Furthermore, IBP has not demonstrated that the permit,

issued without the contested condition,

would not cause a violation ofthe Environmental

Protection Act (415 ILCS

5/1

et seq.)

(Act) or applicable Board

regulations.

We believe that this is a very straightforward case, which turns on the validity of certain

monitoring data points

submitted by IIBP and determined by the Agency to be “outliers.”

Neither the majority opinion nor IBP provides any technical support for overturning the Agency’s

conclusion.

In making

its permitting decisions, the Agency applied its standard

methodology in

accordance with its applicable guidance document to

determine the appropriate sulfate discharge

level for IBP’s permit.

In determining which data to use when applying this methodology,

the

Agency applied Nalimov’s test (an

accepted methodology for examining the validity ofvalues

in a

data set) to the data set

submitted by IBP.

This analysis demonstrated that there were three

definite outliers2

in the data set,

including the

1,808

mg/I value upon which the majority relies in

establishing the permit level.

While an Agency guidance document does not have the force and effect of a rule, IBP has

not challenged the Agency’s methodology for calculating its maximum

daily sulfate effluent level.

Nor has IBP challenged the validity ofNalimov’s test.

IIBP has not even challenged the assertion

The term outlier is

a mathematical term that

is defined as an observation that

is unusually large or small relative

to the other values

in a data set.

Definite outlier status indicates that

there is a

very high degree ofcertainty that there is a gross error associated

with the value.

that the

1,808 mg/l data point is valid,

sincethere were no

operational upsets at its facility, and

since its analytical laboratory has standard operating procedures which were followed.

They have

provided no explanation as to why the sulfate level was approximately four times higher than the

levels measured immediately preceding

and following the 1,808 mg/I value.3

IBP’s assertions do

not constitute sufficient grounds for overturning the Agency’s decision, and the truth ofthese

assertions does not affect the validity ofthe Agency’s determination that these points are outliers.

The fact that the disputed data points are definite outliers for the data set submitted by

IBP means that these points are not bona fide values,

and should not be considered when

establishing a sulfate permit limit.

Ifwe assume that the data set submitted by IBP is sufficient for

establishing a permit

limit, as the Agency was required to do, we cannot use these data points, but

must instead rely on other data points which havebeen determined to be valid.

Alternatively, if

the data points properly characterize IBP’s effluent,

as IBP would have us believe, then the data

set itself must be insufficient, since the disputed data points are uncharacteristic ofthe data set.

Faced with this situation,

it was appropriate for the Agency to set the permit limit at

1,529

mg/I;

even the 1,390

mg/I

value underlying that limit was characterized by Nalimov’s test as a probable

outlier.

By relying on an invalid data point, the Board has allowed IBP to avoid compliance with

the Board’s regulations.

As the majority properly points out, 35 Ill.

Adm.

Code Section

302.102(a) provides an exception to

the prohibition in

Ill. Adm.

Code Section

304.105

against

dischargers causing or contributing to a violation ofany water quality standard.

The exception

Section 302.102(a) allows certain dischargers, who are already providing the best degree of

treatment, to use small portions ofreceiving waters to effect mixing with their effluent,

subject to

certain limitations set forth in Section 302.102(b).

Section 301.1 02(b)(12) requires that the area

ofallowed mixing be as small as practicable.

As the majority points out, the limitations in Section

302.102(b) are intended to insure that “the volume ofwaters used for allowed mixing are

small as is practical,

such as to limit impact on aquatic life, human health,

and recreation.”

(See

majority opinion at 7,

quoting

In The Matter ofAmendments to Title 35,

Subtitle C (Toxic

Control) R88-2 1, Docket A, January 25,

1990,

107

PCB 281.)

However, by relying on an invalid

data point to set the effluent level in IBP’s permit at an insupportably high level, the majority will

allow the area ofallowed mixing to exceed the size that would be the smallest practicable.

This

will permit IBP to cause an exceedence ofthe water quality

standard for sulfate in an area larger

than that supported by the valid data submitted by IBP,

in violation ofthe prohibition

in Section

302. 102(b)(12).

Additionally, by determining that the absolute highest effluent limit for sulfate is

1,808

mg/I, the majority has also

actually increased IBP’s exposure to potential

enforcement for effluent

limit violations.

It may very well be that 1BP’s next recorded “high” value will exceed

1,808 mg/I.

IBP cannot now claim as a defense that values in this range are outliers.

Furthermore, we believe that the majority’s decision reverses the burden ofproof in this

permit appeal and

conflicts with the accepted division ofenvironmental regulatory functions in

~The sulfate levels immediately preceding and following the

1,808

mg/i value were

569

mg/I and

538

mg/i,

respectively.

(Agency Brief

15.)

Illinois.

The burden is on a petitioner challenging the Agency’s permitting decision to

demonstrate that the permit, if issued without the contested

condition, would not violate the Act

or Board

regulations.

While the Agency has the opportunity to contest evidence offered by a

petitioner, it is not required to meet a burden ofproofin supporting its

permitting decision; the

Agency can rely on the permitting record.

In this case,

IBP has failed to sustain its burden ofproof

Again, we point out that it is

not IBP who has challenged the Agency’s methodology, the validity ofNalimov’s test, or the

application ofthat test.

Rather, it is the majority which has implicitly raised these challenges, and

then ruled in its own favor on each.

Having done so, the majority has disregarded a critical

element ofthe Agency’s permitting methodology, ignored the Agency’s technical support

for its

position, and shifted the burden ofproofto

the Agency.

In sum, the petitioner has provided no

valid grounds for challenging the Agency’s

technical analysis in this matter, other than its

unsupported assertions that the “definite outlier”

data point (1,808 mg/I) is valid.

The majority,

by second-guessing the Agency’s methodology,

has attempted to usurp the Agency’s permitting function and replace it with a “common sense,”

ad hoc

decision-making process unsupported by technical analysis.

Claire A. Manning,

Chairman

Marili McFawn, Boar~i

Member

I, Dorothy M.

Gunn, Clerk ofthe Illinois~PollutionControl Board, hereby certify that the

above dissenting opinion was submitted on the

‘~‘~

day of___________

1996.

Dorothy M.

~unn,

Clerk

Illinois Pollution Control Board