ILLINOIS POLLUTION CONTROL BOARD

November 7,

1985

IN THE MATTER OF:

GENERAL MOTORS CORPORATION

)

R83-7

PROPOSED AMENDMENTS TO

35 ILL,

ADM. CODE 900,103 AND 901,104

CONCURRING OPINION (by J,

Marlin):

I have several concerns about

the proposed first notice

Order and Opinion which could be addressed during the first

notice period.

The record demonstrates

to my satisfaction that the current

rules

require modification to allow uniform,

reproducible

measurements of sound,

It~salso clear that the Leg methodology

has gained wide acceptance and

is appropriate

for most sounds.

When interpreted as maximum levels,

the standards in

Sections 901,102 through 901,104 are quite

strict.

They do not

provide for averaging the sound as do the generally accepted

24

hour or one year day/night Leg standards,

In

fact,

they are

significantly more strict than the

65 Ldn standard which has been

widely accepted.

The Board Opinion should recognize that the

proposed change will

in fact weaken the standards regarding

maximum noise levels as presently enforced given that the

Illinois EPA has not used Leg to determine compliance.

This by

itself

should cause no alarm since the Illinois standards will

still

be quite strict even after Leq

is applied to Sections

901.102 and 901,103.

The specified one—hour time also makes

the

proposed rule strict

in that

it will allow the Agency to measure

during the noisiest hour

(R,

150),

A question before

the Board should be, according to current

thinking, what noise standards are necessary to protect the

public health and welfare,

The old numerical values should not

be blindly retained or rejected, especially when the measurement

method

is being altered.

In

its 1973 Opinion,

the Board listed

the degree

of speech interference and some other anticipated

impacts of the sound levels allowed under the existing standards

(pp.

27 and

28).

It

is

reasonable to ask

if the proposed change

should be accompanied by

a change

in the numerical standards.

The proponent

has indicated that the existing numbers are

adequate,

The Board should hear from others on this question.

In 1973 the Board decided to use specific octave band limits

in Sections 901.102 and 901,103 rather than A—weighted limits

(p.

26).

Has experience with A—weighted

levels produced any reason

to reverse

this prior holding?

Will the continued

use

of the

86~375

---

2

octave band limits create any problems

in light of the Leg

methodology?

My primary concern

is that the use of

a one hour Leg

essentially eliminates

the impulsive sound

rule,

The proponent

points out that this

is not necessarily bad

in light of

the

averaging that the proposed rule will impose,

However,

additional comment on the potential of excessively

loud,

short

duration sounds which would be

in compliance with the proposed

rule

is

in order,

Likewise,

I wonder how one will determine when

to use the limits

in Section 901,104

instead of 901,102 or

9ul,103,

Is there an adequate definition of the measurement

method

to be followed

in separating the Leg of the impulsive

noise from the Leq of

the non—impulsive noise?

Is there

a need for some sort of maximum instantaneous

decibel standard?

Would

it make sense

to replace the impulsive

noise standards with such an instantaneous maximum standard?

If

so what would be appropriate levels

for an instantaneous maximum

standard

that would adequately address the health and annoyance

concerns?

Proposed Section 901,130 appears to be somewhat

vague.

I

assume

that someone seeking an alternative measurement procedure

would desire

a more instantaneous time frame than the one hour

Leq,

In accepting Leg,

the Board would be acknowledging that

the

numerical levels

in the rules could be exceeded within the

confines of

the averaging rule,

What numerical standard would

then reasonably apply?

Again

it seems

that some sort of

instantaneous maximum would be useful,

I do not believe that proposed Section 901,130 should

in any

way limit

a person~sright

to participate given

the inability

of

most people

to track Board proceedings

in a timely manner,

~

~/~oardMember

I,

Dorothy

M, Gunn, Clerk of

the Illinois Pollution Control

Board,

hereby certify

that the above Concurring Opinion was submitted

on the

______________

day of

~

1985.

/V

~

~-~•

~/~‘

Dorothy

M,

Gunn, Clerk

Illinois Pollution Control Board

66~376