BEFORE

THE ILLINOIS

POLLUTION

CONTROL

BOARD

IN THE

MATTER

OF:

PROPOSED

AMENDMENTS

TO

TIERED

APPROACH

TO

CORRECT

WE

ACTION

OBJECTIVES

(35 111.

Adni

Code

742)

Dorothy

Gunn,

Clerk

Illinois

Pollution

Control Board

James

R.

Thompson

Center

100 W.

Randolph,

Suite 11-500

Chicago, illinois

60601

(Via First

Class Mail)

Matt

Dunn

Environmental

Bureau

Chief

Office

of the

Attorney

General

James R.

Thompson

Center

100

W. Randolph,

12

th

Floor

Chicago,

Illinois

60601

(Via

First

Class Mall)

Participants

on

the

Service

List

(Via First

Class

Mail)

NOV

142008

POIjtj

STATE

OPHJJNO,S

Control

8oaj

Bill

Richardson

Chief

Legal Counsel

Illinois

Dept.

of

Natural

Resources

One

Natural

Resources

Way

Springfield,

Illinois 62702-1271

(Via

First

Class Mail)

Richard

McGill

Hearing

Officer

Illinois

Pollution

Control

Board

James

R.

Thompson

Center

100W.

Randolph,

Suite

11-500

Chicago,

illinois

60601

PLEASE

TAKE

NOTICE

that

I

have

today

filed

with

the

Office of

the

Clerk

of

the

illinois

Pollution

Control

Board the

Illinois Environmental

Protection

Agency’s

(“illinois

EPA”)

Errata Sheet

Number

I and

the Pre-filed

Testimony

of

Gary

King.

Thomas

C.

HornshawTracey

Hurley.

and

Atul

Saihotra

a copy of

each of

which

is

herewith

served upon

you.

ILLINOIS

ENVIRONMENTAL

PROTECTION

AGENCY

BJ4425

)

)

)

)

)

)

)

R09-9

(Rulemaking-Land)

1ER

OFFICE

NOTiCE

1

&imberly

i/ Geving

Assistant

Ctounsel

Division

of

Legal Counsel

---

NOV14

21108

STATE

OFIWNOIS

)

R09-9

POll

LJtjOn

Cotoj

Board

)

(Rulemaking-Land)

)

CLER!CS

OFFICE

NOV

142008

STATE

OF

ILLINOIS

ERRATA

SHEET

NUMBER

1

Pollution

Control

Board

NOW

COMES

the illinois

Environmental

Protection

Agency

(“illinois

EPA”)

through

one of

its altorneys,

Kimberly

Geving,

and

submits

this

ERRATA SHEET

NUMBER

I

to

the

Illinois Pollution

Control

Board

(Boardn)

and

the

participants

listed

on the

Service

List.

Gary

King,

TraceyHurley,

and

Thomas

C. Homshaw

will

provide

testimony

in

support

of

these changes

at the

hearing

on January

27,

2009.

Section

741410(b)

AGE

•

of

the

fol14

1

””’

approaches:

1)

—Prescriptive

Apptoaoh:

A)

If

more

thai 15%

of

thc-goundwater-oumpling

rosultci

for-a

ehemical

obained

in aocor.daBe,e

with

subseetion

(a) of

this

Section

are less-than

the

appropriate

detectiei-limit

for

that

itn1

the

Preserij>tive

Approach

may not

heneeti

fur

riiiCfti.

If4-54

or less

of-the

sampling

reau4ts sre

.nii-uu

appropriate

detection

limit,

a

conaenatipn

‘-iJ-uuv

half tha

detection

limit

shall

be uped-i

fhnt

ea4 -in the

cnlc&nlipns

contaffied-in

this

Preseriptive

B)

munctwatep-eemnhinf

re

tf-f)htrn

ned in -wôruicmee

BEFORE

THE

ILLINOIS

POLLUTION

CONTROL

BOARD

IN

THE

MATTER

OF

PROPOSED

AMENDMENTS

TO

TIERED

APPROACH

TO

CORRECTIVE

ACTION

OBJECTIVES

(35

III.

Adm.

Code

742)

.ground

shall

be-determined

accoram

6

—

that

ohc

lestl

ehew

—

Approach.

The-

with

subsection

(a.) of

this

Seotion

shall be used-to

determine-

if-tho

sample

et is nennally

distributed

The

Shapiro Wilk

Test of

Normalityehall-bc

usetho-dotermine

whether-the

sample-act

is normally-distributed,

if the

sample

-set for

the

brick-ground

well(s)

contains

50

or

fewer

1

---

sampleoValue

aecessay

for the

Shapiro

Wilk

Teo-ef

Normality Ghall

be

determined

ualng

Appendix

A,

Tab

let

C

end-fl.

If

the

computed-value

of

W

is-greater-than

thci4%

Crionl—Vulue

in-Appendix

A,-Table

D,

the sample

set

shaM

be-assumed

to-be-nonnally

distributed,

and

the

Prescriptive

Approach

is

al4wed.

If

the

computed

value

of W is less

then

5<3<,

Ctiea1-Value

in

Appendix

A,

Table

1), the

sample

set

shall

be aaumed

to

not

be

normally disthbutetl-and

the

Pfescriptive-Approach

shall

notl,e used.

C)

If

the

saniple-set-contains

at

least-ten-

sample

results,

the

Upper

Tolerance-Limit

(UTL)

of

a-normally

distiibuted

sample

set

may

be-eulculatod

using the-rn

ccxi

(x)

and

standard

deviation(&)

from:

UTL—

x

+

(K

Whore

K

—the-one

sided neirnal

tolerance

fao4er

for

esating

the

95<3<.-upper

confidence-limit

af-the

95<

percentile

of-a

nomial

distnbution.

Values for

K-shall

be

determined

ming-Appendix

A,

Tablo.

D)

If tho-semple

set

contains-at

least

ten sample

reu1ts,

the

UTL

shall-be-the

upper

limit

of the area

background

cone

ntratien

fer the-

site. If

the-

sample-set

centains-fewor

than

ten

sample

results,

the-maximum

value-of

the sample-set

shall

be

the

upper

limit

of-the-area

backaround

concentration

for

the-site

nr-aqh-shafl

not

be

used

for-dcterminin-a

area

oucicgrounu

icr

me

parameter

nT-i

(b)

Area

background

shall

be determined

by

using

a

statistically

valid

approach

appropriate

for

the

characteristics

of the

data set

that is

approved

by

the

Agency.

742.1210(c)(4)

Remove this

subsection

from

the

proposai.

Appendix

A

Table

A

For

the

chemical 2-Chiorophenol

(ionizable

organic)

change

l.OOE+05

to 1 .OOE+04

and

change

7.OOE+04

to

7JOE+03.

For

the chemical

Dichiorofluoromethane

change

the

spelling

to Dichiorodifluoromethane

and

change

the

820E+04 to

S.70E+02.

For

the

chemical

Mercury

(elemental)

in

the

Soil

Component

of

the Groundwater

ingestion Exposure

Route

column

change the

3.1 OE+OO

to

.

2

---

For the chemical

Vinyl

acetate

change

the

2.26E+03

to

2QB+O3.

Appendix

A,

Table F

Under

the

category of

the

Respiratory

System

add

l3-Dichloropropene

(cis

+

trani)finhalation

only)

just before p-Dioxane

(inhalation

only).

Appendix

A,

Table

L

For the chemical

2-Chlorophenol

(ionizable

organic)

change

4.90E+04

to

4.90E+03.

For the

chemical

Mercury

(elemental)

change

4.50E-0l

to l.05E+00.

Appendix

B, Table

A

For

the

chemical 2-Butanone

(MEK)

change

the

Outdoor Inhalation

value

from

13,0001)

to

250

d

For the chemical 2-Chiorophenol

change

the

Outdoor

Inhalation

value

from

100

,

000

d

to

10000

d

For

the chemical

I

,4-Dichlorobenzene

(p

Dichlorobenzene)

change

the

Thgestion

value

from

l20eto.QQ.

For

the chemical

1,3-Dichloropropene

(1,3-

Dichioropropylene,

cis

+

trais)

change

the

Class

I

value from

0.003c

to

0.0052e

and

change the

Class

XI

value

from 0.015

to

0.026.

For

the chemical

Methoxychior

change

the

Class

I

value

from

l

4

to

4.

and

change

the

Class

II

value

from

14

dt

0

For the chemical

2,4-Dichiorophenol

change

the

Class

II

value

from

3.3k

to

i2.

For

the

chemical 2,4,6

Trichlorophenol

change

the

Outdoor Inhalation

value

from

430e

to

For

the chemical

Cobalt

change the

Ingestion

value

from

0

600

bt

l,

and change the

Outdoor

Inhalation value

from

1,1

OOe

to

360e

Appendix

B, Table

B

For the

chemical

&omoform

change

the

footnote

under the

Construction Worker

Ingestion

column

from an “e”

to a “b”.

3

---

For

the

chemical

2-Butanone

(MEK)

change

the

IndustrIal/Commercial

Outdoor

Inhalation

value

from

21,000”

to

25

000

d

and change

the

Construction

Worker

Outdoor

Inhalation

value

from

140”

to

730

b

For the

chemical

Chloroform

change

the

Construction

Worker

Ingestion

value

from

2

,

000

btO

4.000c.

For

the

chemical

2-Chlorophenol

change

the

Industrial/Commercial

Outdoor

Inhalation

value

from

1001000

d

to

10

,

000

d,

change

the

Construction

Worker

Ingestion

value

from

10,000”

to

1600

b,

and

change

the

Construction

Worker

Outdoor

Inhalation

value

from

100000

d

to

For the

chemical

Dalapon

change

the

Construction

Worker

Outdoor

Inhalation

value from

120,00&

i

i,ooo.

For

the

chemical

DL)D

change

the

Construction

Worker

Outdoor

Ingestion

value

from

3()e

to

For

the

chemical

1 ,2-Dibromo-3-chloropropane

change

the

Construction

Worker

Outdoor

Inhalation

footnote

from

“b” to

“e”,

For

the

chemical

Di-n-butyl

phthalate

change

the

Class

I

value

from

1,100’

to

880

d

and

change

the

Class

11

value

from

5,600T

to

For the

chemical

1.,4-Dichlorobenzene

(p

Dichlorobenzene) change

the

IndustriailCommercial

Ingestion

value

from

1,100’

to 140,000”,

change

the

Industrial/Commercial

Outdoor

Inhalation

value

from

6.2c

to

20000

b

and

change

the

Construction

Worker

Outdoor

Inhalation

value

from

8.8 to

3201.

For

the

chemical

1

,3-Dichloropropene

(1,3-

Dichioropropylene,

cis

+

trans) change

the

Class

I

value from

0.003c

to 0.0052

and

change

the

Class

fl

value

from

0.015

to 0.026.

4

---

For

the chemical

24-Dimethy1phenol change

the

Construction Worker

Ingestion value from

4

l,OOO

to

100b

For the chemical 2,6-Dinitrotoluene

change

the

Class

U

value

from o.OoO

to

ooolgr.

For

the chemical

Di-n-octyl phthalate change

the

Industrial/Commercial

Ingestion footnote

from

a

“d

to

a

“b”.

For

the

chemical

Hexachiorocyclopentadiene

change

the Class II value

from 1

30

d

to

For

the

chemical

Isopropylbenzene (Cumene)

change

the Construction

Worker Ingestion

value

from

82,

00b

to

820

jb

For the chemical Methoxychior

change the

Class

I

value from

14d

to

4

and change the

Class

IT

value

from

14d

to

For

the chemical

2-Methyiphenol (o-Cresol)

add

a

footnote ‘a” after the value

in

the

Construction

Worker

Outdoor

Inhalation column.

For

the chemical

N-Nitrosodiphenylamine

change

the footnote

“e” to

“b” in

the

Construction

Worker

Ingestion column.

For

the

chemical N-Nitrosodi-n-propylamine

change

the

Industrial/Commercial

Outdoor

Inhalation

value from

to O22

and

change

the

Construction

Worker

Outdoor Inhalation

value

from

1,

900d

to

O.31e.

For

the

chemical 2,4,5-TP

(Silvex)

change

the

Construction

Worker Ingestion value from

l6O,OOOl

to

L600b.

For

the chemical

2,4-Dichlorophenol

change the

Class II

value

from

3,3’

to

For the

chemical

2,4,5-Trichiorophenol

change the

Construction Worker

Ingestion value

from 2OO,OOO’

to

5

---

For

the

chemical

2,4,6-Trichiorophenol

change

the

IndustriallComniercial

Outdoor

Thhalation

value

from

820t

to

630e,

change

the Construction

Worker

Ingestion

value

from

11

,oooc

to

2000

b

and

change

the

Construction

Worker Outdoor

Inhalation

value

from

l,200c

to

89CC

For the

chemical

Antimony

change

the

Construction

Worker

Ingestion

value

from

41

b

to

For

the

chemical

Chromium,

ion,

hexavalent

change

the footnote

in

the

Construction

Worker

Outdoor

Inhalation column

fxm

a

4‘

b”

to an

“e”.

For

the

chemical

Cobalt

change

the

lndustriallCommercial

Ingestion

value

from

4l,000’

to

change

the Industrial/Commercial

Outdoor

Inhalation

value

from

I,Sooe

to

and

change

the

Construction

Worker

Ingestion

value

from

12

,

000

b

to

610

b,

Add

a new footnote

“aa” at the

end

of

the

footnotes

to read:

Calculated

values

correspond

to

soil

concentrations

that should

not

result

in

air

concentrations

that

exceed

criteria

for

workplace

alL

Appendix

B,

Table

G

For

the

chemical

2-Butanone

(MEK)

change the

Soil

Gas

Residential

value

from

440,000

to

380

O0O

and

change

the

Soil Gas

Industrial/Commercial

value

from

2,700,000

to

380.000g.

For

the chemical

2-Chiorophenol

change

the

Soil

Residential

value

from

49,000c

to

4,90Cc,

change

the Soil

lndustriallCornrnercial

value

from

49,00Cc

to

4,900c,

change

the

Groundwater

Residential

value

from

220

,

000

h

to

22

,

000

h,

and

change the

Groundwater

Industhal/Commercial

value

from

220,000

to

22000

h

For

the

chemical

1,4-Dichlorobenzene

change

the

Soil Residential

value

from

I

.3

to 130,

change the

Soil JndustriallCommercial

value

from

98

d

to

J1QY

change the

Groundwater

Residential

value

from

6

---

085d

to

19,

change the Groundwater

Industrial/Commercial value

from 6’ to

change

the Soil

Gas Residential

value

from

317d

to

84

g

and change

the Soil Gas Industrial/Commercial

value

from

27

OdtO

g,

400g

For the

chemical Mercury

change

the

Soil

Residential value from

O45

to

I

O5

and

change

the

Soil

IndustriallCon-imercial value

from O.45

to

l.

05

c,i.

Change

footnote

“i”

by deleting

“Mercury is

measured in mg/L.”

and

replace it

with

“Value for

the

inhalation

exposure

route is

based on

Reference

Concentration

for elemental

mercury

(CAS No.

7439-97-6).

Inhalation remedialion

objectives

only

apply at

sites where elemental mercury

is a

contaminant of concern.”

Appendix C,

Table E

For the chemical

2-Chlorophenol change the

Solubility

in

Water entry

from

2.20E+05 to

22EO4,

For

the chemical 2,4,5-Trichiorophenol

change

the

Solubility in Water

entry

from

8.OOE+02

to

1 2OE+O3

and change the

Dimensionless

Henry’s

Law Constant (H’)(25°) entry from

3.53E-04 to

1

.78E-04.

For

the

chemical

2,4,6-Trichlorophenol

change the

Solubility

in Water entry from I .2O+O3

to

8OOE+O2 and

change

the

Dimensionless

Henry’s

Law Constant (H’)(25°) entry

from

L78E-04

to

153E-04.

Appendix

C,

Table

3

fri the

pH header

row

change

Hg

to

Hg(+2

for

the

entire

table.

7

---

DATE: November 12, 2008

1021 North Grand Ave. East

P.O.

Box 19276

Sprirtg±ield, Illinois 62794-9276

(217)

782-5544

8

Respectfully submitted,

ILLINOIS

ENVIRONMENTAL

PROTECTION AGENCY

By:

Assistant

berlyA.G

Counsel

ng

(J

Division

of

Legal

Counsel

---

ILLINOIS

POLLUTION

CONTROL

BOARD

IN

THE

MATTER

OF:

)

NOV

142008

PROPOSED

AMENDMENTS

TO

)

R09-9

TIERED APPROACH

TO CORRECTWE

)

(Rulemaking-Land)

ACTION

OBJECTIVES

)

(35

III. Adm.

Code 742)

)

PRE-FILED

TESTiMONY OF

THOMAS

C.

HORNSUAW

Qualifications

My

name is Thomas

C.

Hornshaw.

I

am a Senior

Public Service

Administrator

and

the Manager

of

the Toxicity

Assessment

Unit of

the Illinois

Environmental

Protection

Agency

(“Agency”)

I

have

been

employed at the

Agency

since

August

of 1985,

providing

expertise

to

the Agency

in

the area

of environmental

toxicology.

Major

duties of

my

position

include

development

and

use

of procedures

for toxicity

and risk

assessments,

review of

toxicology

and

hazard

information

in

support of

Agency

programs

and

actions,

and

critical review

of risk assessments

submitted

to

the

Agency

for various

cleanup

and

permitting

activities.

I

was a

member

of the Agency’s Cleanup

Objectives

Team

until

February

of

1993,

when

that

Team’s

responsibilities were

assumed

mainly

by

the

Toxicity Assessment

Unit,

I

was also a

member of

the

Groundwater Standards

Technical

Team during

the

development

of the

Groundwater

Quality

Standards.

These two

teams

have

looked in

depth

at the

problems

involved

with

determining

acceptable

residual concentrations

of

chemicals

in

soil

andlor

groundwater-

I

have

also

participated

in

the

development of

the original

35

IlL

Adin.

Code

Part 742 rule,

Tiered Approach to

Corrective

Action Objectives

(“TACO”;

R97-14)

and

subsequent

amendments

to this rule.

1

---

I

received

Bachelor

of Science (with

honors) and

Master

of Science

degrees

in

Fisheries

Biology from

Michigan

State

University.

East Lansing,

Michigan.

I

also

received

a dual

Doctor

of

Philosophy

degree from

Michigan State

University,

in Animal

Science

and Environmental

Toxicology.

I am

a

member

of

the

Society

ofEnvironmental

Toxicology

and Chemistry

and

Sigma

Xi,

the

Scientific

Research

Society.

I have

authored

or co-authored

six papers

published in peer-reviewed

scientific

journals,

one report

issued

through

the

US.

Environmental

Protection Agency,

and have

written

or

co-written six

articles

which have appeared

in trade journals.

I

have

also presented twenty-one

posters

and/or talks describing

facets

of my

graduate work and

my

work at

the

Agency

at

various

regional and national

meetings.

A

more

descriptive

account of

my work and

educational

background

and

a

list

of

publications,

posters,

and talks

is

included

in

a

Curriculum

Vitae

presented

as Exhibit

1

to

this

testimony.

Testimonial Statement

It

has

recently

come

to the

Agency’s attention

that the

procedure

specified

in

TACO

currently for the determination

of area

background for

groundwater at

Section

742.410(b)(l),

the

“Prescriptive

Approach,”

is

now

out

of date

and must be

updated.

In

the

current

approach,

if

the data set

for

a

background

well

has no

more

than

15%

non-detect

results for

the

chemical

of

interest, is normally

distributed,

and has

at

least 10 sample

results, then

the area

background

concentration for

that chemical is

calculated as the

95%

Upper

Tolerance Limit

(“UTL”)

using the

calculation specified

in Section

742.410(b)(l)(C).

The Agency

selected

this

approach

at the

time

TACO

was first

proposed

because

this was the

approach recommended

by the

United States

Environmental

Protection

Agency (“USEPA”)

for

establishing

groundwater background

levels

at

RCRA

2

---

sites in “RCRA

Facility

Investigation

Guidance,

Interim

Final,”

EPA 530/SW-89-03

1

(May 1989)>

and its follow-up

document

“Statistical

Training Course

for

Ground-water

Monitoring Data

Analysis,” EPA 530-R-93-003

(1992).

Now,

however,

USEPA

has

developed

updated

guidance

for

determining

background

groundwater levels,

“Statistical

Analysis of Ground-water

Monitoring

Data

at

RCRA

Facilities-Unified

Guidance,”

USEPA,, Office

of Solid

Waste,

I

999c

(in

progress).

This

guidance

specifies

a

number of statistical

approaches

for determining

background

groundwater

concentrations,

with

the

approach

to

be

used dependant on

the

characteristics

of

the

data

set. It

is noteworthy that the

UTL statistic

is not among

the approaches

recommended

by

USEPA. It is

also

noteworthy

that

in

a remediation

project

overseen

by

the

Agency,

the responsible party

is

in

the process

of determining

the area

background

for

nitrate

in

groundwater,

in which the

UTL

will

eventually

be

calculated to

be in the

range

of

50-55

mg/I.

This concentration

of

nitrate is

also in

the

range at

which

potentially

serious

effects might be experienced

by

infants.

In

keeping with the updated

guidance,

the Agency

is

proposing in Errata

Sheet

Number I to update the

determination

of

area

background

for

groundwater

in Section

742.410. We

recommend removing

all

of the

current

subsection

742.410(b) and

replacing

it

with

a new

subsection

(b)

as follows:

(b)

Area

background

shall be

determined

by using

a

statistically

valid

approach

appropriate for

the

characteristics

of

the

data set that

is

approved

by

the

Agency.

This

concludes

my

testimony

on Errata Sheet

Number

1.

3

---

EXHB1T

1

CURRICULUM

VITAE

THOMAS

C.

HORNSHAW

EDUCATiON:

Ph.D., Animal

Science and

Environmental

Toticology,

1985. M.S.,

1981,

and

B.S.,

1976,

Fisheries

Biology, Michigan

State University.

EXPERIENCE:

Senior Public Service

Administrator,

Illinois

Environmental

Protection

Agency,

1985-

Present.

Graduate Research

Assistant, Department

ofAnirnal

Science, Michigan State

University,

1981-

1984.

Graduate Research

Assistant,

Department

of

Fisheries and Wildlife,

Michigan State

University,

1978-

1981.

Student

Aide,

Water

Quality

Division, Biology Section,

Michigan

Department

of

Natural

Resources,

1976- 1977.

FiELDS

OF

EXPERIENCE:

AE

the illinois

Environmental

Protection

Agency, Dr.

Hornshaw’s

major

duties include

the management

of the Toxicity

Assessment

Unit;

development

and

use

of

procedures

for human

and

environmental

exposure

assessments

and

risk

assessments;

review of

toxicological

data

and

hazard

information

in

support

of

Agency programs

and

actions;

and

critical

review

of

remedial

investigation

and

risk

assessment

documents

submitted to the

Agency

during

hazardous

waste

site

investigations

and cleanups. Dr. Hornshaw

was

a

member

of

the

Agency’s

Cleanup Objectives

Team

until

1993,

when that Team’s

functions

were

assumed

by

the

Toxicity Assessment

Unit. As

a

member

of

Agency work

groups,

he

participated in

the

development

of

ilhinois=

Air

Toxics,

Groundwater

Quality,

and

Tiered

Approach

to

Corrective

Action

rules.

He is

one of the

Agency’s

representatives

to

the

Great

I.akes

Toxic

Substances

Control

Agreement

(member

of

the

Fish

Advisory

Task

Force)

and

is

the

Chair

of

the

multi-agency Illinois

Fish

Contaminant

Monitoring

Program. Dr.

Hornshaw

was

also a

member

of

the

National

Advisory

Committee

for

Acute

Exposure

Guidance

Levels,

moderated

by

USEPA, whose task

is

the development

of action

levels

for

use

in

unplanned

air

releases

of

hazardous

chemicals.

In an earlier

assignment at

the Agency,

Dr. Hornshaw

assisted

in

the

development

of bioassay

protocols

and quality

assurance

procedures

for the

Biomoniroring

Unit.

As

part of

his

duties

during

his

Ph.D- research

at Michigan

State University,

Dr. Hornshaw

conducted

experiments

to

develop protocols

for mammalian

wildlife

dietary

LC

50 and

reproduction

tests,

using

mink

and

European

ferrets

as representative

mammalian

carnivores. He

has

published

four

papers in

scientific journals as

a result of

this

research, and the

protocols developed

from

these

studies

have

been

published

by

USEPA.

As

part of

his

duties

during his

M.S. research

at

Michigan

State,

Dr.

Homshaw

conducted

experiments

to

assess

the

suitability

of

several species

of

Great Lakes

fish for

animal feed,

testing the

fish

in

reproduction

trials

with mink. He

quantitated levels

of polychiorinated

biphenyls in

fish,

mink

fat,

and

mink

milk

as

a

portion of

this research,

and published the

results

of

these studies

in

a

scientific

journal.

These

results

were also

published in

several trade

journals serving

the fur industry.

He

has

---

authored or

co-authored

articles detailing

the

results

of several other

studies

sponsored

by the

fur

industry

in these trade journals.

After

receiving his Bachelors

degree from

Michigan

State, Dr.

Hornshaw

worked

as a student

aide

in

the

Biology

Section of the Water

Quality

Division

of

Mic.higans

Department

of Natural

Resources.

His duties included

assisting

staff

aquatic

biologists

in the collection

of fish, water,

sediment,

and

benthos

samples, in

laboratory

work, in data

handling,

and in

reporting

requirements.

His

field

experience included

sample collection

and

identification

from inland

lakes,

Great Lakes,

and

rivers

and

streams.

HONORS:

Bachelor of

Science, with honors;

Member,

Sigma

Xi,

the

Scientific Research

Society.

AFFILIATIONS:

Member,

Society

of Environmental

Toxicology

and

Chemistry.

THESES:

Horrishaw,

T. C.

1984.

Development

of

Dietary

LC

50 and

Reproduction

Test Protocols

Using

Mink

and Ferrets

as

Representative

Mammalian

Carnivores.

Ph.D.

Thesis,

Michigan

State University,

East

Lansing,

Ml. 2l

2

pp.

V

Hornshaw,

T.

C.

1981.

Renewed

Use of

Underutilized

Species

of Great

Lakes

Fish for

Animal

Feed.

M.S.

Thesis,

Michigan

State

University,

East

Lansing, MI.

45pp.

PUBLICATIONS

(Peer

Reviewed):

Ringer,

R. K., Hornshaw,

T.

C.,

and

Aulerich, R.

J.

Mammalian Wildlife

(Mink and

Ferret)

Toxicity

Test Protocols

(LC

5

Q,

Reproduction,

and Secondary

Toxicity). U.S.

Environmental Protection

Agency

Report No.

EPA/600/3-91/043,

July

1991.

NTIS Document

#

PB91-216507.

Hornshaw,

T.

C.,

Aulerich, R.

J.,

and

Ringer, R. K.

1987. Toxicity of

thiram

(tetramethyhhiuram

disulfide) to

mink and European

ferrets. Bull.

Environ.

Contam.

Toxicol.

38: 618 - 626.

Mornshaw,

T.

C.,

Ringer,

R. K.,

Aulerich,

R.

J.,

and

Casper,

H. H.

1986.

Toxicity of

sodium

monofluoroacetate

(Compound

1080)

to mink

and European ferrets.

Environ.

Toxicol.

Chem.

5:

213-223.

Horrishaw,

T. C., Aulerich, R.

1.,

and

Ringer,

R.

K. 1986.

Toxicity

of o-cresol

to mink

and

European

ferrets.

Environ.

Toxicol. Chem.

5:

713 -720.

Hornshaw,

T. C.,

Safronoff,

J.,

Ringer,

R. K, and Aulerich,

R.

J.

1986. LC

50

test

results

in

poiychlorinated

biphenyl-fed

mink: age,

season, and

diet comparisons.

Arch.

Environ.

Contam.

Toxicol.

15:

717 - 723.

---

Bleavins,

M. R.,

Aulerich,

R.

J.,

Hochstein,

J.

R.,

Hornshaw,

T.

C.,

and Napolitano,

A.

C.

1983.

Effects

of excessive

dietary

zinc

on

the

intra-

uterine

and postnatal

development

of

mink.

J.

Nutr.

113:

2360-236?.

Hornshaw,

T.

C.,

Aulerich,

R.

J.,

and

Johnson,

H.

B.

1983.

Feeding

GTeat

Lakes

fish

to mink:

effects

on

mink

and

accumulation

and

elimination

of

PCBs

by

mink.

J.

Toxicol.

Environ.

Health

11:

933

-

946.

PUBLICATIONS

(Trade

journals):

Hornshaw,

T

1992.

illinois’

Air

Toxics

selection

process

described.

National

Air

Toxics

Information

Clearinghouse

(NATICH)

Newsletter.

USEPA

Office of

Air

Quality

Planning

and

Standards,

Research

Triangle

Park,

NC.

January,

1992.

Aulerich,

R.

J.,

Napolitano,

A. C.,

and

Hornshaw,

T.

C.

1986.

How

supplemental

copper

affects

mink

kit

hemoglobin

concentration.

in

The

Fur

Rancher

Blue

Book

of Fur

Farmjg.

Communications Marketing,

Inc.,

Eden

Prairie,

MN.

pp. 42

- 46.

Hornshaw,

T.

C.,

Aulerich,

R.

3.,

and

Ringer,

B..

K.

1985.

Mineral

concentrations

in

the

hair

of

natural

dark

and

pastel

mink.

Scientifir

9(3):

216

- 219.

Aulerich,

K.

J.,

Napolitano,

A.

C.,

and

Hornshaw,

T. C.

1985.

Effect

of

supplemental

copper

on

mink

kit

hemoglobin

concentration.

Fur

Farmer’s

Gazette

of

the United

Kingdom

35(4):

8

- 11.

Hornshaw, T.

C.,

Aulerich,

R.

J.,

Johnson,

H.

B.,

and Ringer,

R.

K. 1982.

How

suitable

are

todays

Great

Lakes

fish

for use

in

feeding

mink?

Fur

Rancher

62(9):

21

- 23.

Hornshaw,

T.

C.,

and

Aulerich,

R.j.

1980.

Can

Great

Lakes

fish

again

be

fed

safely

to mink?

In

The

xir

Rancher

Blue

Book

of

Fur Farming.

Communications

Marketing,

inc., Eden

Prairie,

MN.

pp.

48

.49

PRESENTAT!

ONS:

Hornshaw,

T.C.

“The

illinois

Fish

Contaminant

Monitoring

Program”

Talk

presented

at

the

27

th

Annual

Fall

Meeting,

Midwest

Regional

Chapter,

Society

of

Toxicology, November

7,

2008,

Downers

Grove,

1L.

Hornshaw,

T.C.

“illinois

EPA

Pilot

Study:

PPCPs

in

Illinois

Drinking

Water.”

Talk

presented

at

the

Meds

with

Water...Not

in

Water

Pharmaceutical

Summit

Conference,

October

1,

2008,

Springfield,

IL.

Willhite,

M.

and

Hornshaw,

T.

“Illinois

EPA

Study

of

Pharmaceuticals in

Drinking

Water.”

Talk

presented

at

the Illinois

Wasts

Management

and

Research

Center

Symposium

on Pharmaceuticals

and

Personal

Care

Products

(PPCPs)

in

the Illinois

Environment,

April

25,

2008,

Champaign,

IL

Hornshaw,

T.C.

“Emerging

Contaminants:

What

Next

to Worry

About?”

Talk

presented

at

the

---

Illinois

Lake

Manage rnent

Association Annual

Conference,

February

28-29, 2008,

Springfield,

IL

Hornshaw,

T.C. and Homer,

D.

LCaIumet

Ecotox

Protocol:

Protecting Calumer’s

Plants,

and

Animals.”

Talk presented at

the Calumet

Research Summit,

January 10-11,

2006,

Hammond,

IN.

Hornshaw,

T.C.

‘Background

Metals

and

PARs - Panel

Discussion.”

Session

Chair

and

Panel

Member

at the

Midwestern

States

Risk Assessment

Symposium,

August 25-27,

2004,

Indianapolis)

IN.

Hornshaw,

T.C.

Intrusion

Action Levels

- Panel

Discussion.”

Panel Member

at

the

Midwestern

States Risk

Assessment

Symposium,

July

24-26,

2002,

Indianapolis, IN.

Hornshaw,

T. C.

AThe

illinois

Strategy

for

Endocrine

Disruptors.@

Talk presented

atThe

Endocrine

Disruptor

Debate: Environmental

Chemicals

and

Reproductive

and

Developmental

Health,

October

17, 1997.

St. Paul, MN.

Hornshaw, T. C. ARisk

Pathways and Exposure

Potential

as

Critical

Factors

in

the

Determination

of

Remedial

Objectives.@ Talk presented

at

the Science

for

Environmental

Professionals

and

Attorneys

Conference,

january 8,

1997,

Chicago, IL.

Hornshaw,

T.

C.

APotential

Health Effects

of Triazine

Herbicides

and Their

Metabolites

in

Community Water

Supplies.@ Talk presented

at

the

1996

Illinois

Agricultural

Pesticides

Conference,

January

3-4,

1996,

Champaign,

IL.

Hornshaw,

T.

C.

‘The

Illinois

Fish

Contaminant

Monitoring

Program.” Talk

presented

at

the

Biannual

Meeting

of

the

Federal-State Toxicology

and Risk

Assessment

Committee

(FSTRAC),

November 6-8,

1991,

Chicago,

IL.

Hornshaw,

T.

C. ‘Assessing

Exposure

to Toxic Air

Releases from

a Chemical Facility:

Illinois

Acrylonitrile

Exposure Assessment.’

Talk presented

at the National

Governors’

Association

Conference

on

Assessing

Exposure

to

Toxic

Contaminants:

Issues

and Problems Facing

State

Government,

March

29, 1989,

Salt Lake

City,

UT.

Horoshaw, T.

C.

“Risk Assessment from

State Point

of View.”

Talk presented

at

the

1st

Annual

Hazardous

Materials

Management

Conference/Central,

March 16,

1988,

Chicago,

1L.

Perino,

1.

V.,

Whitaker,

J.

B.,

and

Hornshaw, T.

C.

Technical

aspects

of an

aquatic

toxicological

testing program

at a state regulatory agency.

Poster

presented

at the

1st Annual Meeting

of the

Ozark-

Prairie Chapter

of the

Society of

Environmental

Toxicology

and

Chemistry,

April

24-26,

1986,

Columbia,

MO.

Hornshaw,

T.

C.

“illinois

EPA’s Aquatic Toxicity

Testing

Program.” Talk

presented

to

the

illinois

Environmental

Consensus

Forum.

December

12,

1985. Springfield,

IL.

Aulerich, R.

J.,

Bursian,

S.

J.,

Nachreiner,

R.

F.,

Olson,

B. A., Hochstein,

J.

R.,

Hornshaw,

T.

C., and

Koudele, K

A.

Toxicological

manifestations

of

dietary

exposure

to

3,4,5,3,4’,

5’. hexachlorobiphenyl

in

mink.

Poster

presented at the

24th Annual

Meeting

of

the

Society of Toxicology,

March

18-22,

---

1985, San

Diego,

CA.

Hornshaw,

T.

C.

“Effects

of Feeding

Great

Lakes

Fish

to

Mink.

Talk presented

at the

Great

Lakes

Commercial

Fisheries

Workshop,

March

12,

1985,

Mackinaw

City,

Ml.

Hornshaw,

T.

C.,

Safronoff,

j.,

Aulerich,

R.

J.,

and Ringer,

R.

K.

Development

and

validation

of

dietary

LC

50

test

protocols

for wildlife

mammalian

carnivores

using

mink and

ferrets.

Poster

presented

at the 5th

Annual

Meeting

of

the

Society

of Environmental

Toxicology

and

Chemistry,

November

4-7,

1984,

Arlington,

VA.

Hornshaw,

T.

C.,

Ringer,

R.

K,

and Aulerich,

R.

J.

Toxicity of thiram

to

mink

and

European

ferrets.

Poster

presented

at

the 23rd

Annual

Meeting

of

the

Society

of Toxicology,

March

12-16,

1984,

Atlanta,

GA.

Horrishaw,

T.

C.,

Ringer,

R. K.,

and

Aulerich,

R.

J,

Toxicity

of

sodium

monofluoroacetate

(Compound

1080)

to

mink.

Poster

presented

at

the

22nd

Annual

Meeting

of the

Society

of

Toxicology,

March &11,

1983,

Las

Vegas,

NV.

Hornshaw,

T.

C.,

Aulerich, R.

j.,

Johnson,

H.

E.,

and Ringer,

R. K Suitability

of

today’s Great

Lakes

fish

for

animal

feed. Poster

presented

at the

International

Symposium

on

PCBs in

the

Great

Lakes,

March

15-17,

1982,

East Lansing,

Ml.

---

BEFORE THE

ILLINOIS

POLLUTION

CONTROL

BOARD

IN THEMATTER

OF:

)

CVED

PROPOSED

AMENDMENTS

TO

)

NOV

j

TIERED

APPROACH

TO CORRECTIVE

)

R09—9

ACTION

OBJECTIVES

)

(35

IlL

Adrn. Code 742)

)

PRE-I?ILED

TESTIMONY

OF

GARY

KING

Oualifications

My

name

is

Gary

King. I

am

the Acting

Chief

for the

Bureau of

Land

at

the Illinois

Environmental

Protection

Agency. Since 1990,

1

have

been

senior manager

for the

Illinois

EPA

site

cleanup programs: the

voluntary cleanup

program,

federal and state

Superfund

cleanup

programs,

Department

of

Defense

cleanup

program,

Brownflelds

assistance

program

and

the

Leaking

Underground

Storage Tank program.

I led

illinois

EPA’s

development

of

the

original

35

III.

Mm.

Code

Part

742

rule,

Tiered

Approach

to

Corrective

Action

Objectives

(TACO,

R97-l4)

and all

subsequent amendments.

I

also chaired

the

Association

of

State and Territorial

SoTid

Waste

Management

Officials

(“ASTSWMO”)

CERCLA Research

Center

from

January

2001 to October

2008.

In

that

role

I

had

frequent contact

with

other States and

U.S

EPA concerning

important

issues

to

State

and

federal

Superfund

programs.

Prior

to

1990, I

managed

Illinois

EPA

land

enforcement

programs.

I am

an

attorney

and

hold a B.S

degree

in civil engineering

from Valparaiso

University.

Testimonial Statement

I will

be

testifying in

support

of

the

proposed

amendments

to

35

Ill. Adnt

Code

742:

Tiered

Approach

to Corrective

Action

Objectives.

I

will present

an overview

of

the

pathway

I

---

evaluation and

tiered

approach

to the indoor

inhalation

exposure route; describe

the

derivation

of

the Tier

1

remediajion

objectives

for

the indoor

inhalation

exposure

mute,

including

the

recommended parameter

values

for the modified Johnson

and

Ettinger

(J&E) model;

and

explain

the

rationale and requirements

for the

use

of

soil

gas data and

building control technologies.

Subpart

A: Introduction

Section

742.115 introduces

the exposure

routes to

be evaluated

under

this

Part,

including

the

indoor inhalation

exposure

route. Similar

to the

groundwater

ingestion route,

the

indoor

irthalation route has

both a soil and

groundwater component.

In

addition,

it has

a

soil

gas

component.

The

soil

component is the

migration of

contaminants from

soil

through

soil

gas

into

a

building

interior.

The

groundwater

component is

the migration of

contaminants from

groundwater

through soil

gas into a

building

interior. This pathway

is

unique

in that

it

involves

three types

of

media:

soil,

groundwater,

and soil

gas.

SubDart

B: General

Section

742.200

contains

new

definitions

for

the

terms

“building,”

“building

control

technology,”

“soil gas,” and

“soil

vapor

saturation limit.”

Assigning

a specific

meaning

to

“building”

will

avoid

confusion

as to

whether

the indoor

inhalation pathway

must

be evaluated

for every

structure.

The

use

of

“building

control

technology”

describes

mitigation

systems for

indoor

inhalation risks and

is

compatible

with

the

existing

term

“engineered

barriers”

“Soil

gas”

merits a

definition now

that

it

has become a

medium

of

interest

as does

“soil vapor

saturation

limit,”

which parallels

the definitions

of “soil saturation

limit”

and “solubility.” The

amended

definition

of “soil

saturation

limit”

is

actually

language

taken

from

an

original footnote

contained

in

Appendix

B,

Tables

A and B. The footnote

offered the better

explanation.

As for the

amended

definition

of

“volatile

cbeinicals”

it

resulted

from a

re-examination

(and

eventual

deletion)

of

2

---

the

original

definitions of

“volatile

organic

compounds” and

“volatile chemicals.”

Today

the

term

is used to

define

contaminants subject

to

evaluation

under

the

indoor

inhalation

exposure

route,

including elemental

mercury.

Section

742.210

contains

19 new

incorporations

by

reference.

The most

notable

of

these

are

U.S. EPA’s

draft

guidance,

Evaluating

the

Vapor Intrusion

to Indoor Air

Pathway

from

Groundwater

and

Soils, which established

the use of

the

J&E model,

and

its

companion

document,

Users

Guidefor

Evaluating

Subsurface

Vapor Intrusion

into

Buildings,

which

provided

justification for certain

parameter

values.

Other

significant publications

include

ASTM

International’s Standard

Practice

for

Assessment

for Vapor

Intrusion

into Structures

on

Property

Involved

in Real Estate

Transactions

and the

Interstate

Technology

and

Regulatory

Council

(ITRC)’s

Vapor

Intrusion Pathway:

A Practical

Guide. Additional

incorporations

have

been

included

to

provide

soil gas

analytical

methods, source

information for parameter

value

selection,

and techniques for

mitigation systems.

Section

742.222

provides

methods

for determining

the soil vapor

saturation

limit and

parallels

Section

742.220,

which is used for determining

the soil

saturation

limit. The

soil

vapor

saturation

limit

is

the

maximum

vapor

concentration that can

exist in

the soil

pore air at

a

given

temperature

and

pressure.

Section

742.Appendix

A,

Table

K

presents the

soil vapor

saturation

limits for

volatile chemicals.

For the

indoor

inhalation exposure route,

soil

gas

remediation

objectives

cannot exceed

the

soil vapor

saturation limit;

otherwise, the

assumptions

of the

modified J&B

model would

be

violated.

The

modified J&E model

as

well

as

the

existing

RBCA

and

SSL

models operate on similar

assumptions

regarding

soil

saturation

and

solubility.

These

risk-based

models assume

an equilibrium

between

contaminant

concentrations

that

exist

as

vapors

in

soil

pores, contaminants

that

adhere

to

soil

particles,

and contaminants

that dissolve

3

---

into

water within

soil pores.

In

Section

742.225, compositing

and averaging

of

sample

results

are

not allowed

to

demonstrate

compliance with the

indoor inhalation exposure route.

Compositing

of volatile

chemicals

is

already prohibited

under

this

Section

(the

physical

mixing

of

samples

in

the

field

provides

a

mechanism for the contaminants

to

volatize

and escape into the

atmosphere;

subsequent sample

analyses

would underestimate the amount

of contamination actually

present

at a site).

As for sample averaging,

first,

and

most important,

is the concern that

averaging

could

allow

a

‘hot spot” of contamination

to remain

beneath

a building

that

could result

in

a

concentrated ‘slug” of chemicals entering the

building

in a

relatively short period

of time. It

is

possible under such conditions

that

these short-term,

higher-level concentrations

could result

in

odor,

irritation, and even central nervous system (headache,

nausea,

etc.)

problems.

Second,

it

is

unlikely

that a sufficient number

of

soil a.ndlor

groundwater samples will

be collected

for

the

indoor inhalation

exposure route to allow

for the

development

of

statistically valid 95 percent

upper confidence

limits

(UCLs)

for

this

route. Third, an

appropriately

conducted indoor

inhalation

exposure evaluation

would

typically include

sampling

in

two

or more

seasons, and

procedures for

deriving the

most

representative statistic for such data

sets can be

problematic.

For

these reasons, illinois

EPA

decided that averaging for the

indoor inhalation route

would not

be

included,

except in Tier 3.

Nonetheless,

we

would be willing to evaluate an

averaging

methodology

if it

adequately

addressed

the

concerns we have

raised.

Illinois EPA

acknowledges

that

there are likely

to.be

site-specific

circumstances in

which

averaging

results

would

be appropriate,

and

that

an

outright

prohibition against averaging

is

not

needed. Therefore, Section

742.225(b)(5)

allows for averaging

in Tier

3

based upon

an illinois

EPA-approved plan.

4

---

Section 742.227

provides

minimal requirements

for

the

collection

and

analysis

of soil

gas

samples.

Ordinarily, sampling

locations,

quantities

and

protocol

are determined

by the

program

under which

the

remediation

is being

performed

(LUST, RCRA.

Site Remediation

Program);

however,

because the use

of soil gas data

is

not

as well

understood

by

site

evaluators,

Illinois

EPA decided

to specify

the

most

essential criteria

to reduce

the likelihood

of

error,

the

misrepresentation

of

actual conditions,

and the need

for repeat

sampling.

Sihart

C: Exposure

Route

Evaluations

Section 742.3

12

identifies ways in which

the

indoor

inhalation

exposure

route

may

be

excluded from consideration.

Indoor inhalation

presents

a

risk only

if

volatile chemicals

are

the

contaminants

of

concern. If a

site has none

of

the

59

chemicals

listed in Section

742.Appendix

A,

Table

I

or

any

other

contaminants meeting

the new

definition

of

“volatile

chemicals,”

then

the

indoor inhalation

pathway

does not

need to be evaluated.

If

volatile

chemicals

are present,

the site evaluator

has the option

of excluding

the

pathway

by

either

restricting

buildings

above

contaminated

areas

or

by

implementing

building

control technologies.

The

general

pathway

exclusion criteria

of

existing

Sections

742.300

and

742.305

must

also be

met; these are

the “speed

bumps”

to

prevent

free product,

the leaving

behind

of

materials

with the potential

impact

of

hazardous waste,

and concentrations

of

polychiorinated

biphenyls

above 50

parts

per

miflion.

The new

building-specific

exclusions would

need

institutional controls

as

follows:

I.

A

land

use

restriction

prohibiting

a

building

or man-made

pathway

above

the

contaminated

soil

or

groundwater.

(The

indoor inhalation

exposure route

is

incomplete

if a building

does

not

exist.)

2.

Operation and

maintenance

requirements

for

approved

building

control

5

---

technologies, including

sub-slab

depressurization,

sub-membrane

depressurization

or

membrane

barriers. These

requirements

are contained

in the new

Subpart

L:

Building

Control Technologies.

The indoor

inhalation exposure

route

cannot

be excluded

by

use

of

a

groundwater

ordinance. This exclusion

is

not

allowed because

an ordinance

restricting

the

use

of groundwater

as a

source of

drinldng water would

not protect

the enclosed

air space

of

a

building from

the

migration

of

contaminants

emanating

from

the

groundwater.

Subpart E:

Tier

I Evaluation

A

Tier

1

remediation

objective

is

a

numerical chemical concentration

that

represents

a

level of

contamination

at

or below

which there are

no human health

concerns.

Sites

achieving

residential

Tier 1

remediation

objectives are

intended

to

clearly indicate

that the

property

meets

an

unrestricted

land use category

for that category

of use,

Tier

I requires a

determination

of

either

residential or

industriallcornmercial

land use. Generally,

equally protective

but less

restrictive

remed.iatiori

objectives

apply

to the

industrialJcornrnercial

sites. [Note:

whenever

remediation

objectives are

based

on

an industriallcommercial

land

use,

an institutional

control

rnustbe

placed on

the

property

in

accordance

with

Section 742.1000(a)(i).]

Early

in

the rulemaking

development,

SRAC

proposed

that

indoor

air OSHA standards

should

apply in lieu of

TACO

at facilities

where

the chemicals

of

concern

continue to

be used

or

manufactured.

Illinois

EPA disagreed

since vapor

intrusion

potentially

impacts the entire

building

and all of

its

occupants.

The

OSHA

standards

may

be more narrowly

applied

to

a

subset

of

workers

and do not account for

the future use

of

the property.

As with

the

other

exposure routes, the

indoor inhalation

remediation

objectives are

calculated

based on

a one-in-a-million

individual excess

cancer

risk

for chemicals

causing

6

---

carcinogenic

adverse

health

effects

and a

hazard

quotient

of one

for chemicals

causing

noncarcinogenic

adverse health

effects.

Risk-based indoor inhalation

remediation

objectives were

derived from

equations

combining

exposure

assumptions

with

toxicity

data. The steps

used

to

develop the

soil1

gToundwater and

soil

gas remediation

objectives

included:

1.

Calculating

a concentration

ofthe

contaminant

of

concern in

indoor

air that

adequately

protects

humans

who

inhale this air (i.e.,

meets the above

mentioned

risk criteria);

2.

Calculating

an

acceptable

concentration

of the

contaminant

of concern

in the

soil

gas at the

source

of

contamination.

This

concentration

will

not cause the

contaminant

in

indoor ar to

exceed

the

concentration

calculated

in Step 1.

This

calculation was

made using

an attenuation

factor derived

from

a

mathematical

model developed

by Johnson and

Effinger

(J&E).

[Note: the ratio

of the

concentration

in the

indoor

air

(Step

1)

to

the

soil gas

concentration is

called

the

attenuation

factor.

Thus the primary

use

of

the

J&E

model is

to

calculate

the

attenuation

factor.]

3.

Calculating

acceptable

soil

and

groundwater

remediation

objectives using

the

soil

gas remediation objective

calculated

in Step

2,

with

the

assumption

that this

contaminant

is

in

three

phase

equilibrium.

The

J&E

model is

preferred

by

U.S.

EPA

and

is the

most common predictive

model

used

by

State

environmental

agencies in

calculating the

attenuation of

contaminant

concentrations

from

the subsurface

to

indoor

air. The

attenuation

factor

accounts for the following

processes:

7

---

1.

Migration

of contaminants

from the source

upwards

through

the

vadose

zone.

The

source

of

contaminant

concentrations

in

the subsurface

may

be

either

soil

or

groundwater.

If

the

source is groundwater,

the attenuation

factor

considers

the

initial migration

of

contanilnants

through

the

capillary

fringe.

2.

Migration

of

contaminants

through

the

dirt

filled

cracks in

the

slab-on-grade

or

basement

floor.

3.

Mixing

of

the contaminants

with

air

inside

the

building.

Dr. Atul Saihotra,

RAM Group,

will

provide testimony

on

the scientific

basis,

fundamental

concepts

and

application

of

the

modified

3&E

model.

Illinois

EPA

provides

IS

J&E

equations

and

56

default

parameter

values

(Section

742.Appendix

C, Tables

L and

M).

Exposure

factors

are consistent

with

the

values

used

in

the

current TACO

regulations.

Toxicity

factors were

obtained

using

U.S.

EPA’s hierarchy

and are

chemical-specific.

Existing

Sections

?42.5O5(b)(3)

and

(4),

which

contain the

procedures

for

addressing

the

additive

effects of

similar-acting

chemicals

in

developing

Tier

1 groundwater

remediation

objectives,

also apply

to the

indoor

inhalation

exposure

route.

Tier

1

remediation

objectives

have been

developed

for

a

slab-on-grade

building.

A

slab-

on-grade

building

is

a

more

conservative

scenario

because

there is

less

air

available

in

the

building to

mix

with

the

contamination.

A

building

with

a

basement

assumes

there

is

mixing

of

the

air between

the

basement

and the

first floor. Tier

I remediation

objectives

are

applicable

to

both

slab-on-grade

buildings

and

buildings with

basements.

A

slab-on-grade

building is

one with a

concrete

floor

at about

the same level

as

the

grade

of

the

surrounding

area;

a

basement

would

tical1y

be below

the

grade

of

the

surrounding

area.

Tier

1

indoor

inhalation

rernediation

objectives

calculated

for

a

slab-on-grade

building are

not

8

---

much

lower

than what would be developed

for a

similar building

with a

basement.

For

ease

of

implementation,

illinois EPA

chose to use

only

one

set

of

Tier

1

remediation

objectives.

Building-specific

default

values

for

the following

parameters

were used

to develop

the

Tier

1 remediation

objectives: length

of

building

),

9

(L

width of

buIlding

(W

8

),heIght

of

building

(H

8

),surface

area

of

enclosed

space

at

or below

grade

(A

8

),

and

building

ventilation

rate

(Qb).

The same default

values must

be used for the same

parameters when

performing

Tier 2

calculations.

The

actual values

of these

parameters

do not

have

a great impact

on the

remediation

objective;

however,

the

default

values

are

based

on a

conservative representation

of

the

type

of

buildings

that

are

or may

be

present at

the

site

in

the

future.

Without

these

conservative

values,

restrictions

would be required

on

the

minimum

size of a

building that can be

constructed over

the

contaminated

area.

For

the indoor inhalation exposure

route,

the industriallcomrnercial

remediation

objective

differs from

the residential

remediation

objective

in

three

ways: exposure

duration,

building

size,

and air

exchange rate. The air

exchange rate (ER)

is

used

to represent

the

mixing

that

occurs

within

a

building. The

air

within a residence

is

assumed

to be

flushed

out

of the

building

at a

rate

of

13.8

times

per day

(0.53

times per

hour)

and

at a

commercial

location at

the

rate

of

22.32

times

per

day (0.93

times per hour)

based on values

listed

by Hers et aL

(2001)

and Murray

and

Burmaster

(1995).

These two

papers are

the source

of

the recommendations

in

U.S. EPA’s

User

‘s Guide for

Evaluating Subsurface

Vapor

Intrusion il2to

Buildings (2004).

Tier

1

indoor

inhalation remediation

objectives

assume

the vadose zone

is composed

of

sand.

The default properties

used are

consistent

with the

existing TACO values

for

sand.

For the I&E equations,

illinois

EPA used

a chemical-specific

value for

Dimensionless

Henry’s Law Constant

set to a

default system

temperature of

13°C.

U.S.

EPA’s

draft

vapor

9

---

intrusion

guidance

— as well

as

the other

exposure routes

in

TACO

— set the

system

temperature

for

Dimensionless

Henry’s Law Constant

at

25°C.

Illinois EPA decided

to use

a lower

system

temperature

for

the

indoor

inhalation

route in

Tiers

1

and

2

because it

is more representative

of

the

groundwater

temperature

in Illinois,

The

groundwater

temperature

in

Illinois

ranges

from

8.3°

C

to

16.7° C;

the

average

within

that range

is

13.190

C.

The lower temperature

reduces

the

Dimensionless

Henry’s Law

Constant, resulting

in

a

less stringent

remediation

objective.

The

States

of New Jersey and Michigan

also apply

a state-specific system

temperature

(13°

C and

12.5°

C,

respectively)

for Dimensionless Henry’s

Law Constant

under the indoor

inhalation

exposure

route.

Section 742.Appendix

B,

Table

G

provides

a

Tier

1 table

of

numerical

soil,

groundwater

and

soil

gas

values

for

both residential

and industrialJcommercial

receptors.

An Acceptable

Detection Limit

(ADL)

column is

also part

of

the indoor inhalation

Tier

1

table

and

applies

only

to soil

remediation

objectives.

The A.DL identifies

the

lowest

practical

quantitation

limit

of any

U.S.

EPA-approved

methodology for any chemical.

For

most

chemicals,

the

column

is noted

with

an asterisk,

meaning the detection

limit is

less than

the

remediation

objective.

Where

this

is

not

the

case, the

ADL

is

used

as

the

remedia±ion

objective. This

parallels

ADL

usage

on

the

existing

Tier

1 look-up

tables, Section

742.Appendix B,

Tables

A

and

B. Remediation

objectives

are

not

provided

for the construction worker

population

since this

receptor group

is

not

at

risk

from

indoor

inhalation

exposure.

The

exposure

duration for indoor

construction

in

almost

all

cases

is

less

than the

exposure duration

for the

residents

or commercial

workers. Thus

the

protection of

these

two receptors

will ensure

protection

of the construction

worker

during

the

period of

indoor construction.

In

addition

to

describing Section

742.Appendix

B, Table (3,

Section

742.515

explains

10

---

how

Tier

1 remediation objectives

for

the

indoor

inhalation

exposure

route are

to

be

used

in

regards

to

the

three

media

(soil,

groundwater

and soil

gas)

and in

conjunction

with

the

existing

Tier

I tables

for

the

other

exposure

routes.

During

the

migTation

of

contaminants

from

soil

and

groundwater

to

a

building’s

interior,

the

contaminants

must

pass through

soil

gas.

U.S.

EPA,

ITRC

and

individual

States

generally

concur

that

the

measurement

of

soil

gas

is

the

most

reliable

indicator

of

a

vapor

intrusion

threat.

However,

many

sites

will

collect

soil

and

groundwater

data

in

characterizing

the

other

exposure

routes

and

will

not want

to do

further,

and

potentially

unnecessary,

field

work.

For

these

reasons,

Illinois

EPA

proposes

that

sites

intending

to

use

numerical

rernediation

objectives

to

demonstrate

compliance

with

the

indoor

inhalation

exposure

route must

meet

either

the

1)

soil and

groundwater

remediation

objectives,

or

2) soil

gas

remediation

objectives.

The

use

of

indoor

air

data

to

demonstrate

compliance

with

remediation

objectives

under

Tier

1

or

2

was

rejected

early

by

Illinois

EPA.

Indoor

air

samples

are

highly susceptible

to

bias

from

occupant

sources

(smoking,

dry

cleaning,

household

chemical

use

and storage,

etc.).

They

•

are

also

invasive,

requiring

site

evaluators

to

obtain

access

to indoor

space.

The

rules

do

not

prohibit

the

use of

indoor

air

data;

however,

any such

request

would

be

a

Tier

3

evaluation.

Under

Tier

1,

separate

chemical-specific

remediation

objectives

are calculated

for each

route,

including

now

the

indoor

inhalation

exposure

route.

If

the

respective

Tier

1

remediation

objective

is not

exceeded

for

a

route,

the

user

may exclude

that

route from

further

investigation

(additional

exposure

routes

may

be excluded

under

Section

742.312).

Of

the

exposure

routes

remaining,

the

most

restrictive

or

health

protective

Tier

1 soil

and groundwater

remediation

objective

from

Section

742.Appendic

B, Tables

A,

B,

E, and

G

is to be

compared

tà

the

concentrations

measured

at

a

site.

This

practice

is

consistent

with

cunent

usage

of

the Tier

1

11

---

tables.

Subpart

G:

Tier

2

Soil Evaluation

Tier

2

remediation

objectives are

developed

using the

J&E

equations

provided

in Section

742.Appendix

C,

Table

L.

fllinois

EPA

is

preparing

a guidance document

for

site

evaluators

thai

will

describe

in

a more

complete

narrative

how Tier

2

equations

for the indoor

inhalation

exposure

route

will

work.

Tier

2

calculations

require

information

on the

physical

and chemical

properties

of the

individual

contaminants

at a

site. As in Tier 1,

a

chemical’s

toxicological

parameters,

physical

parameters

(obtained

from

Section 742.Appendix

C,

Table

E),

and

the

J&E

equations

themselves

may

not

be varied.

This

is

also

true

for

Tier

2

evaluations

applying the

SSL

and

RBCA

models

for the other

exposure routes.

Section

742Appendix

C, Table

M

contains

all

of

the parameters

used

for

the

J&E

equations.

These

parameters use either

default

values

(i.e,

standardized

and/or health

protective

values)

or actual

site-specific

field data. Where

default

values

are

provided,

they may be

used

in

Tier 2

equations.

That is, only partial site-specific

information need

be obtained

and

default

values

may

be

used for the

rest

of

an equation’s

parameter

inputs. This practice

is

consistent

with

Tier 2 evaluations for

the

other exposure routes.

For the indoor

inhalation exposure

route,

Tier

2

differs

from

Tier

1

in

two ways.

First,

the

additivity

of risk from

noncarcinogenie

contaminants

in

soil

must

be

taken

into

account

(as

required for the

other

exposure routes).

Second, the

attenuation factor

is based

on

site-specific

soil

properties,

including:

depth to

contaminated soil; types

of

soil present

beneath

the

ground

surface

and

the contamination source;

and

geotechnical

parameters

(dry soil

bulk density,

soil

total

porosity,

water-filled

soil porosity,

and

fraction

organic carbon content).

12

---

To determine

site-specific

physical

soil

parameters,

a

minimum

of one boring

per

0.5

acre

of

contamination

must be collected.

Each soil

sample analyzed

for

one

or

more

of

the

app licable

contaminants

of concern

must

also

be

analyzed

for water

content; at

sites

where

multiple samples

from

multiple

depths

are analyzed

for contaminants on

a dry weight

basis

and

their

volumetric

water content

can be measured

based

on

available

data, additional

samples

solely

for

analysis

of

water content

may

not

be

necessary.

Samples

for

geotechnical

data are

not required

from

directly under the building.

Samples

collected adjacent

to

a building are acceptable,

In

lieu

of

sampling

the different

soil

types

for

geotechnical

parameters,

use of the

default soil parameters

provided in

TACO

is

also

acceptable.

Soil

parameters

obtained

from

other

literature

searches and not

from

site-specific

determinations

may

be allowed under

Tier

3.

The depth

to

contaminated

media

D)

is

the

shortest distance

from

the

base

of

any

existing or

potential

building (or man-made

pathway into the

building)

to

a location

where

a

sample

result

exceeds

the

Tier

1

value

for a contaminant

of

concern

for the indoor

inhalation

exposure route.

It

is

essential

to

determine the

type

of soil

between

the

ground

surface and

the

contamination

source, as

the contaminants must

migrate

through

this soil before entering

a

building.

Ifthe

site stratigraphy varies

in

this

zone,

it should

be divided into

different layers.

For

each

different

soil

layer, the

soil

type,

thickness,

water-filled

soil

porosity

and

soil total

porosity

are

necessary

to

calculate

the

Tier

2 remediation objectives.

Specifically,

the

water-filled

soil

porosity and soil

total

porosity

are used

to estimate

the

effective

diffusion

coefficient

for

each

layer.

If

the

contaminated

medium

is groundwater,

then

the

capillary

fringe

is

included

as

one

of

the

soil

layers.

13

---

The

geotechnical

parameters — dry soil bulk

density, soil total porosity,

water-filled

soil

porosity, and

fraction

organic

carbon

content — are

used to estimate soil gas

concentrations

at

the

source,

assuming

that the

risk

being calculated

is

based

on representative

soil

concentrations.

Methods for determining

soil

parameters

for

the

indoor

inhalation exposure

route are

provided

in

Section

742

.Appendix

C,

Table

F.

The

most sensitive

parameters

are water content

and

thickness

of the capillary

fringe.

Fraction of organic carbon content

(f) is

also

sensitive;

increasing

f,

increases the

remediation

objectives. Depth

to

soil source is not sensitive because

the

modified

J&E model assumes

an

infinite source with no biodegradation

as the vapors

migrate through the vadose

zone.

Section 742.7 17 explains how the

J&E

equations

are

to be

applied when

calculating

soil

or

soil

gas

remediation objectives for the indoor

iithalation exposure

route.

Equations

J&El

through J&E3 are

used to

calculate the

acceptable concentration

of the contaminant

in

indoor

air.

Equation J&E1

applies only

to chemicals that cause carcinogenic health

effects, J&E2

applies

only to chemicals

that

cause noncarcinogenic health

effects,

and

J&E3

is

used

by

both

types

of

contaminants to convert from

parts per million

volume to milligrams per

cubic meter.

Estimation

of indoor air

remediation objectives

using J&El or

J&E2 requires two categories

of

input

parameters: toxicological information

and

receptor-specific

exposure

factors

(exposure

frequency, exposure duration and averaging

time).

Equation

J&E4

calculates

a

soil

gas

remediation objective using

the appropriate

indoor

air

remediation objective

(from

either J&El

or

J&E2) and an

attenuation

factor

developed

from

Equations J&E8b through J&ElS. The soil gas remediation objective

must

be compared

to

the

saturated vapor concentration

(Ct).

Section

741222

presents

the

methods

by

which the

concentration

is obtained;

for example,

site evaluators

may

use the list

of

values

in

Section

14

---

742Appendix A, Table K or calculate a site-specific

C

using

equation J&E6b.

If

the

calculated soil gas remediation

objective

is greater

than

C,

then

Ct

is

used

as

the

soil

gas

remediation

objective.

When comparing

the

calculated

soil

gas remediation

objective to soil

gas samples

from

the site, Section

742.717(k)

instructs

site

evaluators to use soil

gas

data

collected at a

depth

at

least three feet below the ground surfaee and above

the saturated zone. This

is

to

ensure

the

quality of

the

soil

gas

sample. Samples

taken less

than

three feet

from the

ground

surface

can

be

compromised

by

the

influence of barometric

pressure

fluctuations that

may cause an

influx

of

ambient air

into the

soil,

variations

in

ambient temperature,

and precipitation.

Samples

talcen

from

the

capillary fringe

or below are

unacceptable because

of high water saturation.

Equation J&E5 calculates

soil

remediation

objectives

using

an

equilibrium

conversion,

which assumes

that

the

soil gas is in

three

phase

equilibrium with

the

contaminated

soil

at

the

source.

This calculation takes

into

account

soil-specific

properties — water-filed

soil

porosity,

the

soil-water

partition coefficient, the air-filled soil

porosity, and the dry soil bulk density

— and

uses

a

chemical-specific Dimensionless Henry’s Law Constant

set

at a

system temperature

of

13°C (as in

Tier 1).

The calculated soil

remediation objective

must be compared with the

soil saturation

limit

(C).

Site-specific

C

values for the indoor

inhalation

exposure

route

may be calculated

using

equation J&E6a.

C1

values

for volatile

chemicals

for the indoor inhalation exposure

route

are

also

provided

in Section

742.Appendix

A,

Table

L.

This

table differs from

the

C

table

in

Section

742.Appendix

A,

Table A because it

uses different values

for two parameters:

the

system

temperature used

to

set

the

chemical-specific

Dimensionless

Henry’s Law Constant and

the

fraction

organic

carbon content

().

The soil

component

of

the

groundwater ingestion

exposure

15

---

route

(migration

to

groundwater

pathway)

and the

outdoor

inhalation

exposure

route

use

a

system

temperature

of 25°C. The

rationale

for the

difference

in

system

temperature

(13°

C

instead

of 25°

C)

for

the

indoor

inhalation

exposure

route

has

already

been

described.

As

for

differences

in

f

values,

the migration

to groundwater

pathway

uses

an

f

0.002

(mg/mg)

because

the

contamination

is moving

into

deeper

soils

with

a

lower organic

carbon

contenL

The

outdoor

inhalation

exposure

route

uses

an

f

value

of

0.006 because

the contamination

is

moving

up

through

the soils.

Illinois EPA

decided

to

use an

f

value

of

0.002

for

the indoor

inhalation

exposure

route

because

basements

are

below

surface;

using

a

lower

f

value results

in a

more

conservative

remediation

objective.

If the

calculated

soil

remediation

objective

is greater

than

C,

then

C

is

used

as

the

soil

remediation

objective.

This practice

is

consistent

with

the other

exposure

mutes.

Equation

J&E8b

is used to

calculate the

attenuation

factor. This

is

the

heart

of

the

predictive

model,

measuring

how

much contamination

from the

subsuthce

is

expected

to reach

the

indoor

air.

The

source

of the

contaminant

concentrations

in

the

subsurface

may

be

either

soil,

groundwater

or

soil

gas.

J&E8b

assumes

that

there

is no

significant

pressure

difference

between

the

subsurface

soil

and the building.

This

means that

contaminants

emanating

from

the

source

do

not

migrate

into the

building

by advection.

Migration

by

advection

is

represented

by the

parameter

Q,

also

known

as

the

volumetric

flow

rate

of soil gas

into the enclosed

space.

When

Q

is assumed

to

equal

zero

—

as

is

the case in Tiers

1

and

2

— diffusion

is

the

only contaminant

transport

mechanism.

This is analogous

to

the

indoor inhalation

model included

in the

Appendix

of the

Standard

Guide

for

Risk-Based

Corrective

Action

Applied

at Petroleum

Release

Sites that

assumes the

value

of

Q&i

is negligible

(ASTM

Designation:

E 1739-95).

If

advection

was

occurnng,

site

evaluators

would use equation

J&ESa to

calculate the

attenuation

factor

under

16

---

Tier

3.

The

remaining

equations,

3&E9a

through

J&El

8, are

used

to

establish

the

input

parameters

for

application

in J&E8b.

Equation

J&E9a

calculates

the

total overall

chemical-

specific

effective

diffusion

coefficient.

For

this

equation,

each

layer

of

soil (sand,

loamy

sand,

loam

etc.) through

which

contaminant

vapors

migrate

from

source

to

building

must

be

accounted

for.

The

total

thickness

of

the

soil

layers

must

equal

the

distance

from

the

bottom

of the

slab

to

the

top

of

the

contamination;

this relationship

is presented

in

equation

J&E9b.

The

distance,

called

the

source

to

building

separation

distance,

is

calculated

by

equation

J&ElO.

Equation

J&E1

1

calculates

the chemical-specific

effective

diffusion

coefficient

for each

soil

layer and

is used

in equation

J&E9&

Equations

J&E12a

and

12b

are used

to

calculate

the

surface

area

of

the

enclosed

space

at

or below

grade

through

which

vapors

enter

into

the

building.

For

slab-on-grade

buildings,

site evaluators

must use

J&E12a.

For

buildings

with

basements,

site

evaluators

must

use

J&E12b.

Equation

J&E13

calculates

the building

ventilation

rate

using

the air

exchange

rate

and

the

size

of the

building.

For

equations

J&El 2a,

J&El

2b

and

J&E13,

site

evaluators

must

use

the same

default

values

as in

Tier 1.

Equation

J&E14

calculates

the

area

of

total

cracks

assumed

to

exist

in

the

portion

of

the

structure

below

grade

through

which

contaminants

migrate

into

the

building;

default

values

from

Tier

1

must

be

used here

as

well. Contaminants

intrude

into thebuilding

only

through

cracks

that

completely

penetrate

the

slab;

these cracks

are

assumed

to

be

flied

with

dirt.

The

thickness

of

these

cracks

is

represented

by the

slab thickness,

which

is

set at

10

cm

for both

Tier

1 and Tier

2.

Equation

J&El

5

calculates

the

effective

diffusion

coefficient

through

the

cracks

using

soil

parameters

representative of the

soil within

the

cracks;

as

these

parameters

cannot

be measured

directly,

the

default

values

in

Tier

I

apply.

17

---

Equations

J&E16

through

J&E18

calculate

site-specific

geotechnical

parameters.

J&E16

gives

the

total

porosity,

which

is

the

ratio of the

volume

of voids

to

the

volume

of soil

sample.

J&E17

gives

the

water-filled

soil porosity,

which

is the

ratio

of

the

volume of water

to

the

volume

of

soil.

J&E18

gives the air-filled

soil porosity,

which

is a measure

of

the

total

porosity

minus the

water-filled

porosity.

Porosity

values

representative

of the soil

layer

at the

source

of

contamination

as

well

as each

soil layer

through

which contaminants

migrate are

needed to

calculate

the effective

diffusion

coefficient

(J&E1 1).

Additional

methods

for

determining

the

physical

soil

parameters

are presented

in

Section

74iAppendix

C,

Table

F.

It is possible

to

calculate

a Tier

2

soil

remediation

objective

more

stringent

than the

Tier

I

soil

remediation

objective

for

the

indoor

inhalation

pathway;

in

such

cases,

the

Tier

I

remediation

objective

applies.

This

practice

is consistent

with the

other

exposure

routes

in

TACO.

Subpart

H: Tier

2 Groundwater

Evaluation

Section

742.805(e)

requires

site evaluators

to

follow

Section 742.812

in

calculating

groundwater

remediation

objectives

for

the indoor

inhalation

exposure

route.

Under

Section

742.812,

site evaluators

follow

the J&E

equations

presented

in

Section

742.7

17,

only

equation

J&E7

is

used

instead of

equation

3&E5,

and

when

determining

the

attenuation

factor,

the capillary

fringe

must be

considered

one

of the

layers in

equation

J&E9a.

The

capillary

fringe is

the

zone immediately

above

the saturated

zone

where

capillary

attraction

causes

upward

movement

of

water

molecu.les

from

the

saturated

zone

into the

soil

above;

it contains

more

water

than

the

rest

of

the soil

above the

water table.

This

zone

is

distinct

in

that

it

has characteristics

of both

the vadose

and

saturated

zones.

Because

the

capillary

fringe

impacts

the migration

of

contaminants

from

the water

table, it

must be

considered

as a

separate

18

---

soil layer

when

developing

remediation

objectives

for

groundwater

and

a

default

thickness

of

17

cm must

be

used.

This value

comes from the

U.S. Soil Conservation

Service

soil texture

classification

table,

which is

also used by

U.S. EPA

for

determining

soil-dependent

properties

for

the J&E

model.

In

addition, the

default water-filled

soil

porosity of the capillary

fringe

is

assumed to

be 90

percent

of

the

total

porosity of

the soil that

comprises the

capillary

fringe.

The

thickness

of

the capillary fringe

and

its

water-filled soil porosity

cannot

be measured

accurately

in the field on a

site-specific

basis,

which

is why site-specific

values

are

not allowed.

Subpart

1:

Tier 3 Evaluation

Section 742.900(c)(1

0)

identifies the

use of

building

control technologies

—

different

from

those presented in Subpart

L

— as

a

situation

eligible

for

a Tier

3 evaluation.

Site

evaluators

wanting to perform

a Tier

3 evaluation for reasons

of

impractical

remediation

(Section

742.920)

or exposure

route

exclusion (Section

742.925)

for

the

indoor inhalation

pathway are

directed

to

follow

Section

742.935.

Under

Section

742.935, site evaluators

may

propose

to

use calculations

arid

modeling

to

establish remediation

objectives; use

soil

gas

data,

such as

sub-slab

sampling;

and use

building

control

technologies

different

from

those

presented

in

Subpart

L.

In

‘Section

742.93

5(a), the indoor

inhalation

pathway may be

excluded through

calculations

and

modeling

to account

for contaminant

transport

from soil,

groundwater

or soil

gas

into

a building. Unlike

Tiers 1

and 2,

the

calculation

of

Tier 3

remediation

objectives

for

the

indoor

inhalation

exposure route must

take into

account the

possible migration

of chemicals

caused

by

both

diffusion

and advection.

If

the

contamination

is more

than

five

feet

from

an

existing or

potential building

or man-made

pathway,

a value

of

zero for

the

volumetric

flow rate

of

soil gas into

the

enclosed space

(Q

01)

must

be used.

A

Q

value

of

zero

means that

the

19

---

controlling

mode

of

contaminant

transport is diffusion

and

not

advection.

If the

contamination is

within

five feet

of

an existing

or potential

building

or

manmade

pathway,

then

a

Q

value

of

83.33

cm

3

/sec

must be

used

in calculating

the attenuation

factor

(equation I&E8a),

unless

additional

site-specific

infoimation indicates

a

different

remediation

objective

is

reasonable

and

appropriate.

A

Q

0

assessment under Tier

3

is

a balancing

factor

to

make

sure these

alternative

evaluations

remain

health-protective.

In

Section

742.935(b),

site

evaluators

may

propose to

establish remediation

objectives

using

soil gas data in lieu

of

the

requirements

of

Section 742.227.

One such

difference

is the

use

of sub-slab samples

collected

directly

beneath a

building

foundation.

Section

742.227

applies

to

exterior

samples collected

near

the

building,

which

is

Illinois EPA’s

preferred

approach

as

it

is

the least

invasive. However,

because sub-slab

sampling

is an accepted

methodology

nationwide,

Illinois EPA

decided

to reference

it specifically under

Tier 3. This

section identifIes

what

information

a site

evaluator must

submit to Illinois

EPA to demonstrate

the

validity

of

alternative

soil

gas

data in

calculating indoor inhalation

remediatiort

objectives.

Section

742935(c)

must

be

used

when

site evaluators propose

a

mitigation

system

that

deviates

from the building

control

technology

requirements

presented

in Subpart

L.

This

section

identifies

what

information

a site evaluator

must submit

to

Illinois

EPA

to

demonstrate

the

effectiveness

of

art

alternative

building

control

technology

to

prevent

or

nii.tigate

indoor

inhalation

exposure risks.

Subpart

3:

Institutional Controls

Section 742.l000(a)(7)

requires

the use

of

institutional

controls whenever

rernediation

objectives

are

based on a

building control

technology. Section

742.1015(j)

prohibits

the use

of

a

groundwater

ordinance to

exclude

the

indoor

inhalation

exposure

route. As

described

previously,

20

---

this

is because

an

ordinance restricting

the source

of

drinking

water

would

not protect

the

enclosed

air space

of

a building

from

the

migration

of

contaminants

in the

groundwater.

The

other iostitutionai

controls available in

TACO

for land use restrictions

and engineered

barriers

may stiU be

used, though

Highway

Authority

Agreements

will likely

not

apply

to the

indoor

inhalation

exposure route.

Subpart

L:

Building

Control

Technoloaies

Building control

technologies are

designed to prevent

the

migration

of volatile

chemicals

into enclosed

spaces.

They

control

unacceptable

health risks due to

vapor

intrusion by

reducing

or

eliminating

the concentrations

in

the

indoor

air without

necessarily

reducing

the

residual

concentrations

in soil, groundwater,

or soil

gas.

The

objective

of these

measures is

to make

the

indoor

iriiialation

exposure

route

incomplete

by

preventing

the

migration

of chemicals

into

a