R97012f.PDF

1 BEFORE THE ILLINOIS POLLUTION CONTROL BOARD

3 IN THE MATTER OF: )

)

4 TIERED APPROACH TO CORRECTIVE ) R97-12 (B)

ACTION OBJECTIVES ) (

Rulemaking- Land)

5 35 ILL. ADM. CODE 742, )

9 The following is a transcript of a

10 rulemaking hearing held in the above-entitled

11 matter, taken

stenographically by LISA H. BREITER,

12 CSR, RPR, CRR, a notary public within and for the

13 County of

DuPage and State of Illinois, before

14 AMY MURAN FELTON, Hearing Officer, at the Loyola

15 Law School, One East

Pearson Street, Room 324,

16 Chicago, Cook County, Illinois, on the 21st day of

17 May 1997 commencing at 10:00 o'clock a.m.

L.A. REPORTING - (312) 419-9292

1 A P

P E A R A N C E S:

2 HEARING TAKEN BEFORE:

3 ILLINOIS POLLUTION CONTROL BOARD

100 West Randolph Street

4 Suite 11-500

Chicago, Illinois 60601

5 (312) 814-4925

BY: MS. AMY MURAN FELTON,

6 HEARING OFFICER.

7 ILLINOIS POLLUTION CONTROL BOARD MEMBERS PRESENT:

8 Ms.

Marili McFawn

Mr. Ronald C. Flemal, Ph.D.

9 Ms. Kathleen

Hennessey

10 ILLINOIS POLLUTION CONTROL BOARD TECHNICAL

ADVISORS PRESENT:

Mr. Chuck

Feinen

12 Mr.

Hiten Soni

Ms. Elizabeth Ann

13 Mr.

Anand Rao

14 ILLINOIS ENVIRONMENTAL PROTECTION AGENCY MEMBERS

PRESENT:

Ms. Kimberly A.

Robinson

16 Mr. Gary P. King

Mr. John

Sherril

17 Dr. Thomas

Hornshaw

Mr. H. Mark

Wight

18 Mr. Christopher L.

Nickell

19 OTHER AUDIENCE MEMBERS WERE PRESENT AT THE HEARING

BUT NOT LISTED ON THIS APPEARANCE PAGE.

L.A. REPORTING - (312) 419-9292

1 I N D E X

2 PAGE

3 GREETING BY HEARING OFFICER................ 4 - 10

4 OPENING COMMENTS OF

DR. THOMAS C. HORNSHAW.................... 10 - 12

TESTIMONY OF DR. THOMAS C. HORNSHAW....... 12 - 28

QUESTIONS TO DR. THOMAS C. HORNSHAW....... 28 - 64

CLOSING COMMENTS BY HEARING OFFICER....... 64 - 67

E X H I B I T S:

16 MARKED IN EVIDENCE

Exhibits 1 and 2........... 4.............. 36

L.A. REPORTING - (312) 419-9292

1 (Documents marked.)

2 HEARING OFFICER FELTON: Good morning.

3 My name is Amy

Muran Felton, and I'm the named

4 hearing officer in this proceeding. I would like

5 to welcome you to this hearing in the matter of

6 Tiered Approach to Corrective Action Objectives,

7 35 Illinois Administrative Code 742, docket B.

8 Present today on behalf of the

9 Illinois Pollution Control Board and seated to my

10 left is the presiding board member of this

11 rulemaking, Marili McFawn. Also joining us is

12 Board Member Dr. Ronald Flemal and Board Member

13 Kathleen

Hennessey. Further joining us is Chuck

14 Feinen, attorney assistant to board member Joe

Yi,

15 and

Hiten Soni, Anand Rao and Elizabeth Ann, the

16 board's technical advisors.

17 Over here on the table, I have

18 placed notice lists and service list

signup

19 sheets. Please note that if your name is in the

20 notice list, you will receive copies of the

21 board's opinions and orders. If your name is on

22 the service list, you will not only receive copies

23 of the board's opinions and orders, but you will

24 receive documents filed by all parties in the

L.A. REPORTING - (312) 419-9292

1 service list in this proceeding. Keep in mind if

2 your name is on the service list, you are also

3 required to provide copies of all documents you

4 file with the board to all parties on the service

5 list.

6 You are not precluded from

7 presenting questions if your name is not on either

8 of the notice or service list. If you have any

9 additional questions regarding the notice and

10 service list, please talk to me during one of our

11 breaks. Copies of the board's May 1st, 1997,

12 opinion and order and the notice and service list

13 signup sheet are also on that table. The agency

14 is in the process of preparing a text of the

15 proposed rules including the necessary

16 strike-

throughs and underlines. The board has

17 prepared a draft text of the proposed rules for

18 the sake of this hearing, and that document is

19 also located on the table.

20 This hearing will be governed by

21 the board's procedural rules for regulatory

22 proceedings. All information which is relevant

23 and repetitious or privileged -- strike that --

24 which is relevant or repetitious will be

L.A. REPORTING - (312) 419-9292

1 admitted. All witnesses will be sworn and subject

2 to cross questioning. This hearing will be

3 continued on the record to Thursday, May 22nd,

4 1997, at 10:00 a.m. in the auditorium at the State

5 of Illinois Center in Chicago, if necessary, to

6 accommodate the agency's presentation and response

7 to questions.

8 This proposed

rulemaking was filed

9 on May 1st, 1997, and is intended to fulfill the

10 mandates of Title XVII of the Environmental

11 Protection Act. Title XVII was added to the act

12 by Public Act 89-431 which was signed and became

13 effective on December 15th, 1995. On September

14 16th, 1996, the Illinois Environmental Protection

15 Agency proposed a new part 742 to the board's

16 rules to create a tiered approach to establishing

17 corrective action objectives, also known as

18 T.A.C.O.

19 On November 7th, 1996, the board

20 adopted the T.A.C.O. proposal docket A for first

21 notice. On April 17th, 1997, the board adopted

22 the T.A.C.O. proposal docket A for second notice.

23 The proposed rules in docket B contain amendments

24 to the new, not yet final, part 742. The proposed

L.A. REPORTING - (312) 419-9292

1 rules in docket B were originally proposed by the

2 agency after the close of hearings in docket A.

3 Because the agency's proposed

4 amendments to docket A were proposed after the

5 close of hearings in docket A and the issues

6 raised by the agency could not be resolved based

7 upon the record developed during hearings on

8 docket A, the board found in its May 1st, 1997,

9 opinion and order that there was not sufficient

10 time to resolve these issues and adopt any

11 necessary amendments as a part of T.A.C.O. docket

12 A.

13 Accordingly, the board opened this

14 docket B and found it was necessary to conduct

15 public hearings about the proposed rules pursuant

16 to its own

rulemaking authority under sections 27

17 and 28 of the act. The hearing today concerns

18 those rules proposed in docket B. Generally these

19 rules relate to mixtures of similar-acting

20 substances. The purpose of today's hearing is to

21 allow the agency to present their testimony in

22 support of that proposal and to allow questioning

23 of the agency.

24 Procedurally, this is how I plan to

L.A. REPORTING - (312) 419-9292

1 proceed. We have received one

prefiled testimony

2 from Thomas C.

Hornshaw of the agency.

3 Mr.

Hornshaw will read his testimony into the

4 record for the benefit of all parties to this

5 proceeding. We will then allow the agency to

6 present any supplemental testimony they may have

7 regarding their proposal. Subsequently, we will

8 allow for questioning of the agency regarding

9 their testimony.

10 I prefer that during the

11 questioning period, all persons with questions

12 raise their hands and wait for me to acknowledge

13 them. When I acknowledge you, please stand and

14 state in a loud, clear voice your name and your

15 organization you represent, if any.

16 Are there any questions regarding

17 the procedures I have just stated before we

18 proceed?

19 MS. ROBINSON: Well, would it be

20 possible for the agency to have all witnesses

21 sworn in and answer in a panel format, if

22 necessary?

23 HEARING OFFICER FELTON: That would be

24 fine. At this time I would like to ask Board

L.A. REPORTING - (312) 419-9292

1 Member

McFawn if she has anything else she would

2 like to add to my comments.

3 MS. MC FAWN: Just to welcome you all

4 here. It should be a rather efficient hearing

5 given the people that are here. We're all

6 familiar with T.A.C.O., and the questions have

7 been, I think, pretty well articulated by the

8 board's orders and also by -- framed also by the

9 prefiled testimony we've received. So thank you

10 for coming.

11 HEARING OFFICER FELTON: Board Member

12 Flemal or Board Member

Hennessey, do you have any

13 other additional comments you would like to add?

14 MS. HENNESSEY: No thank you.

15 HEARING OFFICER FELTON: At this time I

16 would ask the agency if they would like to make an

17 opening statement, and we will turn to the

18 agency's presentation of their proposal.

19 MS. ROBINSON: I'm going to let

20 Dr.

Hornshaw do a little opening statement, but as

21 a start matter, I would like to have everybody

22 with the agency introduce themselves.

23 I am Kimberly

Robinson with the

24 Division of Legal Counsel for the Bureau of Land.

L.A. REPORTING - (312) 419-9292

1 DR. HORNSHAW: I'm Tom

Hornshaw. I'm a

2 toxicologist in the Office of Chemical Safety.

3 MR. SHERILL: I'm John

Sherril, a

4 project manager in the Bureau of Land.

5 MR. WIGHT: I'm Mark

Wight with the

6 Division of Legal Counsel.

7 MR. NICKELL: I'm Chris

Nickell, the

8 project manager in the Bureau of Land.

9 MR. KING: I'm Gary King. I'm in the

10 Bureau of Land.

11 (Discussion off the record.)

12 MS. ROBINSON: Could we swear the

13 witnesses, please.

14 (Witnesses sworn.)

15 MS. ROBINSON: Dr.

Hornshaw, if you'd

16 like to proceed.

17 DR. HORNSHAW: Before I read my

18 testimony, I'd like to mention that in our review

19 of the various documents talking about mixtures of

20 similar-acting substances, we found slight

21 discrepancies in the various documents.

22 Errata sheet No. 3, second notice

23 and the proposed version of this docket had slight

24 discrepancies in the language. So our discussion

L.A. REPORTING - (312) 419-9292

1 will be based on what's in my testimony, and

2 that's how we view the way to address the mixtures

3 of similar-acting substances in this proceeding.

4 MS. ROBINSON: Dr.

Hornshaw, I'm going

5 to show you what's been marked by the court

6 reporter for identification as Exhibit No. 1, if

7 you could look at that and tell me if you

8 recognize it.

9 DR. HORNSHAW: Yes, this is a copy of

10 the testimony I prepared for this proceeding.

11 MS. ROBINSON: Is that a true and

12 accurate copy?

13 DR. HORNSHAW: Yes.

14 MS. ROBINSON: And what's been marked as

15 Exhibit No. 2 for identification, would you take a

16 look at that and tell me if you recognize it.

17 DR. HORNSHAW: Yes. This is a draft of

18 proposed language for docket B that was sent to

19 the agency.

20 MS. ROBINSON: Was this drafted by the

21 board?

22 DR. HORNSHAW: Yes.

23 MS. ROBINSON: Okay. Would you please

24 proceed with the reading of your testimony into

L.A. REPORTING - (312) 419-9292

1 the record.

2 MR. RIESER: Excuse me, Ms.

Robinson, is

3 Exhibit 2 the same as draft of agency proposal,

4 copies of which were sent around today?

5 MS. ROBINSON: That's correct.

6 DR. HORNSHAW: Good morning. My name is

7 Thomas C.

Hornshaw. I am a senior public service

8 administrator and the manager of the Toxicity

9 Assessment Unit within the office of Chemical

10 Safety of the Illinois Environmental Protection

11 Agency. I have been employed at the agency since

12 August of 1985, providing expertise to the agency

13 in the area of environmental toxicology.

14 Major duties of my position include

15 development and use of procedures for toxicity and

16 risk assessments, review of toxicology and hazard

17 information in support of agency programs and

18 actions and critical review of risk assessments

19 submitted to the agency for various cleanup and

20 permitting activities. I have previously

21 presented a summary of my qualifications at the

22 first hearing in this

rulemaking and will not

23 repeat them here. My testimony today will be

24 limited to discussion of the agency's rationale

L.A. REPORTING - (312) 419-9292

1 for the development of remediation objectives for

2 mixtures of similar-acting substances in soil and

3 groundwater.

4 I must preface my testimony with an

5 apology to the board and to the other participants

6 in this

rulemaking for the agency introducing new

7 language to part 742 regarding mixtures of

8 similar-acting substances in errata sheet No. 3 so

9 late in the

rulemaking process. Please understand

10 that there was no intent by the agency to sidestep

11 the hearing process or in any other manner to try

12 to undo any agreements reached by the agency and

13 the advisory committee.

14 Rather, as will be demonstrated by

15 this testimony, the agency attempted to clarify

16 the approach to be used at sites where groundwater

17 has been found to be contaminated with two or more

18 chemicals which affect a similar target in the

19 body and to avert potential legal disputes where

20 such conditions were found to exist.

21 The agency has included language

22 for addressing mixtures of similar-acting

23 substances in part 742 from the very beginning of

24 this

rulemaking. This concern for mixtures

L.A. REPORTING - (312) 419-9292

1 derives in part from long-standing agency policy

2 and more importantly from statutory directive.

3 Section 58.4(c)(4)(B) of Title XVII specifically

4 requires that methodologies adopted by the board

5 for determining remediation objectives must ensure

6 that, in quote, "The presence of multiple

7 substances of concern and multiple exposure

8 pathways," end quote, are taken into account.

9 As a result of this concern, the

10 agency included language in Tier 2 of the original

11 proposal requiring that for

noncarcinogens that

12 affect the same target in the body, soil

13 remediation objectives for such

noncarcinogens be

14 adjusted to account for the additive effects of

15 the mixture in soil. This language, which limits

16 the necessity to address mixtures of

17 similar-acting substances to Tier 2 assessments

18 and to

noncarcinogens, came about because of

19 discussions with the advisory committee.

20 Specifically, it was decided that

21 the inherent

conservatisms built into the process

22 of developing the Tier 1 soil remediation

23 objectives made consideration of the

additivity of

24 effects of similar-acting substances unnecessary

L.A. REPORTING - (312) 419-9292

1 -- I'm sorry -- unnecessary in Tier 1. It was

2 only necessary to address mixture effects of

3 noncarcinogens in Tier 2 because for carcinogens,

4 the statutory language of section 58.5(d) of Title

5 XVII specifically provides for the establishment

6 of remediation objectives at an excess lifetime

7 cancer risk of between 1 in 10,000 and 1 in

8 1,000,000.

9 It was agreed that since the

10 statute provides for an acceptable cancer risk

11 range and since even if there are 10 carcinogens

12 present at their respective 1 in 1,000,000

13 remediation objectives (an unusual event) the

14 cumulative cancer risk of 1 in 100,000 is still

15 within the acceptable range. Therefore,

16 consideration of the

additivity of carcinogenic

17 effects in Tier 2 was unnecessary. Since

18 corresponding statutory guidance regarding an

19 acceptable risk range for

noncarcinogens is not

20 provided in Title XVII, the additive effects of

21 noncarcinogens had to be considered and provided

22 for in Tier 2.

23 As a result of the above,

24 provisions relative to mixtures of similar-acting

L.A. REPORTING - (312) 419-9292

1 contaminants in soil are still included in the

2 rules sent to second notice. Regarding

3 groundwater, it was assumed, at least by the

4 agency, that the requirements of 35 Illinois

5 Administrative Code 620.615 regarding mixtures of

6 similar-acting substances would govern the

7 development of remediation objectives at a site.

8 Therefore, the inclusion of language in part 742

9 addressing mixtures of similar-acting substances

10 (carcinogens and

noncarcinogens) in groundwater in

11 any tier was not discussed between the agency and

12 the advisory committee.

13 As stated above, the topic of

14 remediation objectives for mixtures in groundwater

15 had been a non-issue throughout the development of

16 part 742. In fact, it wasn't until late in the

17 hearing process that the agency realized that not

18 including specific language regarding mixture

19 effects in groundwater had become an issue. In

20 the context of recommending remediation objectives

21 for a particular site, the agency included an

22 objective for a mixture of similar-acting

23 substances detected in Class I groundwater and was

24 subsequently questioned whether this type of

L.A. REPORTING - (312) 419-9292

1 objective was allowed by part 742.

2 After some internal discussion, the

3 agency decided that recommending remediation

4 objectives for mixtures of similar-acting

5 substances in Class I groundwater in any tier and

6 for carcinogens and

noncarcinogens is appropriate

7 because it is required by 620.615 because, quote,

8 "multiple substances of concern," end quote, is

9 included in the factors which, by statute, must be

10 addressed when determining remediation objectives

11 for a site and because it is health protective to

12 do so.

13 However, the agency came to realize

14 as a result of this discussion that by either not

15 cross-referencing the requirements of part 620.615

16 or providing an alternative procedure to part

17 620.615 in 742, the door remained open for future

18 debate over the appropriate remediation objectives

19 when similar-acting chemicals are detected in

20 Class I groundwater. Furthermore, the agency

21 foresaw the possibility of a person expecting to

22 receive a no further remediation determination

23 from the agency by virtue of achieving all Class I

24 groundwater objectives only to be told that

L.A. REPORTING - (312) 419-9292

1 further remediation would be necessary because the

2 requirements of part 620.615 have not been met.

3 Even worse, the agency was

4 concerned by the possibility, however remote, that

5 because part 742 is silent about the requirements

6 for mixtures of similar-acting substances in

7 Class I groundwater, a no further remediation

8 letter might be issued and subsequently be

9 challenged for not meeting the requirements of

10 part 620.615. It was with these concerns in mind

11 that the agency informed the advisory committee of

12 its intent to add language cross-referencing the

13 requirements of part 620.615 in Tiers 1, 2 and 3.

14 After admittedly brief discussion, such language

15 was then included in errata sheet No. 3 for the

16 board's consideration.

17 The agency stands by its intent to

18 have the requirements for remediation objectives

19 for mixtures of similar-acting substances in

20 Class I groundwater be very clear. Toward this

21 end, the agency met with the advisory committee on

22 May 12, 1997, to further discuss this issue and

23 the language tentatively included in the proposed

24 rule for R97-12(B) dated April 17, 1997.

L.A. REPORTING - (312) 419-9292

1 The agency's meeting with the

2 advisory committee on May 12, 1997, focused on two

3 general areas regarding mixtures of similar-acting

4 substances, whether it was agreed that the

5 language currently included in part 742 relative

6 to mixtures in soil was still acceptable and

7 whether the language proposed by the board

8 relative to mixtures in Class I groundwater in the

9 proposed rule for R97-12(B) is acceptable. Please

10 note that the following discussion pertains only

11 to Class I groundwater since mixture effects need

12 not be considered in Class II groundwater.

13 Regarding mixtures in soil, it was

14 agreed that the language currently in part 742 is

15 acceptable. Thus, there should still be no

16 requirement to address mixtures of carcinogens or

17 noncarcinogens in soil for Tier 1 evaluations or

18 mixtures of carcinogens in soil for Tier 2

19 evaluations for the reasons discussed above. The

20 only requirements regarding mixtures in soil are

21 for

noncarcinogens in Tier 2 evaluations and

22 consideration of mixture effects in formal risk

23 assessments in Tier 3 evaluations for carcinogens

24 and

noncarcinogens.

L.A. REPORTING - (312) 419-9292

1 Regarding mixtures in groundwater,

2 several issues were discussed by the agency and

3 the advisory committee. It was generally agreed

4 that the original version of part 742 was unclear

5 regarding the requirements for remediation

6 objectives for mixtures in groundwater, although

7 the statute mandates that they be addressed. It

8 was also generally agreed that consideration of

9 mixture effects is required for

noncarcinogens in

10 Tier 2 evaluations and for carcinogens and

11 noncarcinogens in formal risk assessments in Tier

12 3 evaluations.

13 What was still at issue was whether

14 mixture effects needed to be addressed in Tier 1

15 evaluations (carcinogens and

noncarcinogens) and

16 whether carcinogens needed to be addressed in Tier

17 2 evaluations. In-depth discussion of the

18 remaining issues ultimately provided the basis for

19 conceptual agreement on how to address these

20 mixture concerns.

21 On the necessity for addressing

22 mixtures in Tier 1, it was pointed out by the

23 advisory committee members that the statute

24 requires only lookup tables in Tier 1, and

L.A. REPORTING - (312) 419-9292

1 mixtures cannot be addressed in tables. It was

2 also pointed out that there was conservatism built

3 into the development of the Tier 1 groundwater

4 remediation objectives similar to the reasoning by

5 which consideration of mixture effects in soil in

6 Tier 1 was deemed unnecessary. Therefore, it was

7 not necessary to address mixtures in groundwater

8 in Tier 1.

9 On the other hand, it was pointed

10 out by the agency that, as discussed above,

11 consideration of mixture effects was required by

12 both the existing statute (Title XVII) and

13 regulations (part 620) and that for two reasons

14 there is not necessarily the same degree of

15 conservatism built into the Tier 1 groundwater

16 objectives as in the soil objectives. The first

17 reason is that there is an additional layer of

18 conservatism built into the inhalation and the

19 soil component of the groundwater ingestion

20 exposure route soil objectives due to the

21 assumptions made regarding transport in soil.

22 Whereas for the groundwater

23 component of the groundwater ingestion exposure

24 route, the only

conservatisms built into the

L.A. REPORTING - (312) 419-9292

1 development of the remediation objectives are the

2 assumptions regarding the toxicity and the actual

3 intake of the chemical.

4 The second reason is that for

5 certain carcinogens whose Tier 1 groundwater

6 objective is based on the chemical's drinking

7 water standard, the groundwater objective does not

8 have the same degree of conservatism as the soil

9 -- as the corresponding soil objective, that is,

10 1 in 1,000,000 cancer risk as the basis. This is

11 due to the consideration of factors other than

12 risk by USEPA in establishing the drinking water

13 standards such as natural occurrence, for example,

14 arsenic; detection limits, for example, vinyl

15 chloride; or risk/benefit analysis, for example,

16 drinking water

disinfection by-products.

17 On the issue of whether mixture

18 effects of carcinogens need to be considered in

19 Tier 2, it was pointed out by the advisory

20 committee that the statute provides for a range of

21 acceptable cancer risks from 1 in 10,000 to 1 in

22 1,000,000. Therefore, even if 10 carcinogens are

23 present in groundwater at their respective

24 objectives, the cumulative cancer risk still falls

L.A. REPORTING - (312) 419-9292

1 within the acceptable range (again similar to the

2 reasoning by which consideration of the cumulative

3 risk of carcinogens in soil was determined to be

4 unnecessary in Tier 2).

5 In response, the agency again cited

6 the carcinogens whose groundwater objectives

7 exceed the 1 in 1,000,000 cancer risk level and

8 which, if present in a mixture with other

9 carcinogens, could potentially result in a

10 cumulative cancer risk exceeding 1 in 10,000. The

11 agency also again cited the statutory and

12 regulatory requirements to consider mixture

13 effects in groundwater regardless of what tier is

14 used in evaluating a site.

15 Following considerable discussion,

16 conceptual agreement was reached on the remaining

17 issues. Regarding Tier 1, it was agreed that

18 other than for those carcinogens whose groundwater

19 objective is not based on a 1 in 1,000,000 cancer

20 risk, there is an appropriate degree of

21 conservatism in the Tier 1 groundwater remediation

22 objectives such that consideration of mixture

23 effects is not necessary in Tier 1 provided all

24 other contaminants of concern detected in

L.A. REPORTING - (312) 419-9292

1 groundwater achieve their respective remediation

2 objectives.

3 However, if any contaminant of

4 concern (carcinogen or

noncarcinogen) exceeds its

5 respective Tier 1 groundwater remediation

6 objective or if a carcinogen whose Tier 1

7 groundwater objective is not based on a 1 in

8 1,000,000 cancer risk is detected in groundwater,

9 then the potential for cumulative effects of

10 mixtures of such chemicals must be addressed as a

11 Tier 2 evaluation. Regarding Tier 2, it was

12 agreed that only those carcinogens whose Tier 1

13 groundwater objectives exceed the 1 in 1,000,000

14 risk level must be evaluated for mixture effects

15 in Tier 2. It was further agreed that the

16 carcinogens whose Tier 1 groundwater remediation

17 objectives exceed the 1 in 1,000,000 cancer risk

18 level will be specifically identified in part

19 742.

20 In order to include the conceptual

21 agreements discussed above into part 742, the

22 following modifications to proposed rule for

23 R97-12(B) dated April 17, 1997, are proposed:

24 Section 742.505(b)(3), change the proposed

L.A. REPORTING - (312) 419-9292

1 language as follows: "The requirements of 35

2 Illinois Administrative Code 620.615 regarding

3 mixtures of similar-acting chemicals shall be

4 considered met for Class I groundwater at the

5 point of human exposure if the following

6 requirements are achieved:

7 "A) the Tier 1 groundwater

8 remediation objective listed in appendix B, table

9 E for Class I groundwater is not exceeded at the

10 point of human exposure for any contaminant of

11 concern detected in groundwater.

12 "And B) any contaminant of concern

13 listed in appendix A, table H is not detected in

14 any groundwater sample associated with the site

15 using analytical procedures capable of achieving

16 either the 1 in 1,000,000 cancer risk

17 concentration or the ADL, whichever is greater, as

18 listed in appendix A, table H." Then delete

19 subsections (A) and (B) currently found in the

20 proposed rule.

21 Section 742.505(b)(4), add a new

22 section as follows: "Sites which do not meet the

23 requirements of section 742.505(b)(3)(A) shall

24 evaluate mixtures of similar-acting chemicals

L.A. REPORTING - (312) 419-9292

1 using the procedures of section 742.805(c) or

2 section 742.915(h). Sites which do not meet the

3 requirements of section 742.505(b)(3)(B) shall

4 evaluate mixtures of similar-acting chemicals

5 using the procedures of section 742.805(d) or

6 section 742.915(h)."

7 Section 742.805(c) - delete the

8 language currently proposed for second notice in

9 this section and replace it with the language

10 currently proposed -- I'm sorry -- currently

11 listed in the proposed rule for section

12 742.505(b)(3). Then add a board note after this

13 section as follows: "Board note: Use of the

14 procedures specified above in section 742.805(c)

15 may result in groundwater remediation objectives

16 that are less than the Tier 1 groundwater

17 remediation objectives for chemicals included in

18 these procedures."

19 Section 742.805(d) - add a new

20 section as follows: "The requirements of 35

21 Illinois Administrative Code 620.615 regarding

22 mixtures of similar-acting chemicals shall be

23 considered met if the cumulative risk from any

24 contaminant(s) of concern listed in appendix A,

L.A. REPORTING - (312) 419-9292

1 table H, plus any other contaminant(s) of concern

2 detected in groundwater and listed in appendix A,

3 table F as affecting the same target organ/organ

4 system or having a similar mode of action as the

5 contaminant(s) of concern detected from appendix

6 A, table H does not exceed 1 in 10,000."

7 Section 742.900(f) - delete this

8 subsection from section 742.900 of the proposed

9 rule dated April 17, 1997.

10 Section 742.915(h) - substitute the

11 language deleted from section 742.900(f) of the

12 proposed rule above for the language currently

13 listed in section 742.915(h) from second notice.

14 Section 742.915(

i) - create a new

15 section 742.915(

i) by inserting the language of

16 742 -- I'm sorry -- section 742.915(h) currently

17 listed in second notice.

18 And finally, appendix A, table H -

19 create a new table as follows on page 11 of my

20 testimony which I won't read through. Thank you.

21 MS. ROBINSON: Could we have that

22 entered as if read through the exhibit?

23 HEARING OFFICER FELTON: Yes.

24 DR. HORNSHAW: Note: Benzene was not

L.A. REPORTING - (312) 419-9292

1 included in appendix A, table H even though its

2 Class I groundwater remediation objective (0.005

3 milligrams per liter) exceeds its 1 in 1,000,000

4 cancer risk concentration (0.001 milligrams per

5 liter) for the following reason: Benzene only

6 appears in one target organ/organ system category

7 in appendix A, table F (circulatory system) and

8 can only be included in a mixture with one other

9 chemical (2,4,6-trichlorophenol).

10 Even if both benzene and

11 2,4,6-trichlorophenol are present in Class I

12 groundwater at their respective groundwater

13 remediation objectives, the cumulative circulatory

14 system cancer risk is only 7.1 in 1,000,000 which

15 is within the acceptable risk range of 1 in 10,000

16 to 1 in 1,000,000. Therefore, it is not possible

17 for benzene to contribute to an unacceptable

18 cancer risk in a mixture without also exceeding

19 its individual groundwater remediation objective.

20 The agency believes the proposed language

21 discussed above adequately addresses the concerns

22 for which this docket was created. This concludes

23 my testimony on this matter.

24 MS. ROBINSON: Dr.

Hornshaw, I'm going

L.A. REPORTING - (312) 419-9292

1 to show you now Exhibit No. 2. Could you please

2 tell me is there also a change to section 742.105

3 that was not reflected in your testimony?

4 DR. HORNSHAW: Yes, there is.

5 MS. ROBINSON: Could you explain what

6 that is.

7 DR. HORNSHAW: In discussing or looking

8 through the proposed part 742 second notice, we

9 became aware that there was a reference to

10 mixtures of similar-acting substances in the

11 applicability section.

12 I'm sorry, it's not a specific

13 reference to mixtures of similar-acting

14 substances. It's a reference to section 742.805

15 which we have modified according to my testimony

16 today. So because of our changing section

17 742.805, we are deleting the subsection A which is

18 currently referenced in the applicability section,

19 section 105, to make it read just 742.805 to

20 encompass the changes which we are recommending

21 today.

22 MS. ROBINSON: Thank you. Now I'm going

23 to show you also part of Exhibit No. 2 under

24 742.805(c) and ask you if we've added any language

L.A. REPORTING - (312) 419-9292

1 that was not reflected in your testimony there.

2 DR. HORNSHAW: Yes. In section 742.805,

3 again when we were reviewing the language to make

4 sure it captured everything that we intended, we

5 noticed that the language that was proposed in the

6 -- which one was it now? The language that was

7 in the draft of R97-12(B) from the board that was

8 faxed to the agency had language that didn't quite

9 track with how we had proposed in errata sheet 3,

10 in that the requirements specified in this new

11 subsection 805(c) were intended to be an either/or

12 situation.

13 The way the language read in the

14 draft of R97-12(B) made it a requirement that both

15 parts of this section had to be met. So we

16 substituted the language -- I'll just read it.

17 "The requirements of 35 Illinois Administrative

18 Code 620.615 regarding mixtures of similar-acting

19 chemicals shall be considered met for Class I

20 groundwater at the point of human exposure" -- and

21 here is where we added a change -- "if either of

22 the following requirements are achieved."

23 And then to make it completely

24 clear, at the end of subsection 1, roman numeral

L.A. REPORTING - (312) 419-9292

1 (ii), we added "or." The (ii) ends with "less

2 than or equal to one." We added an "or" in there

3 so that it reflects that there's a -- it's in the

4 wrong place actually. Well, there should be an

5 additional "or." Wait a minute, let me make sure

6 this is correct.

7 Yes, the way it's currently worded,

8 the "or" is between roman (

i) and roman (ii), and

9 that "or" should actually be after roman (ii).

10 There shouldn't be a choice between the two roman

11 numerals.

12 MS. MC FAWN: So they'll have to satisfy

13 both small letter (

i) and small letter (ii)? You

14 want to delete the one that appears after the --

15 DR. HORNSHAW: After the first (

i), it's

16 not really a choice. You either meet or you do

17 something else to meet. You can't do both (

i) and

18 (ii).

19 MS. MC FAWN: So you can't do both?

20 DR. HORNSHAW: Right. You either exceed

21 and then you have to go do something else, which

22 is (ii), but if you've met, then you never get to

23 (ii). If you meet (

i), you don't have to go into

24 (ii).

L.A. REPORTING - (312) 419-9292

1 MS. MC FAWN: All right.

2 DR. HORNSHAW: But then you also have a

3 choice between 1 and 2. You don't have to meet

4 either or both of those.

5 MS. MC FAWN: So what's been marked as

6 Exhibit No. 2, you would propose that the "or" at

7 the conclusion of small letter (

i) of section

8 742.805(C)(1), you would propose that that be

9 deleted?

10 DR. HORNSHAW: Right.

11 MS. MC FAWN: And that the semicolon

12 remain?

13 DR. HORNSHAW: In our copy, it's a

14 period.

15 MS. MC FAWN: The last line does not

16 read "for those chemicals" semicolon "or"?

17 DR. HORNSHAW: Not in the version that

18 was faxed to us.

19 MS. MC FAWN: We can deal with that

20 later. Then you propose that we insert the word

21 "or" at the conclusion of 805 -- let me make sure

22 I get this, (C)(1)(ii)?

23 DR. HORNSHAW: That's correct.

24 MS. MC FAWN: So that the last phrase

L.A. REPORTING - (312) 419-9292

1 would read, "In accordance with the equation

2 above, less than or equal to 1, semicolon or"?

3 DR. HORNSHAW: Correct.

4 MS. ROBINSON: When the agency redrafts

5 this version, we are going to commit to send that

6 out to the entire service list hopefully this

7 Friday. That will be reflected in the new draft.

8 MS. MC FAWN: Before we go on, I just

9 want to clarify. The change that you talked about

10 in the first paragraph of 805(c), the words "if

11 either," that is reflected in the copy before you

12 or not?

13 DR. HORNSHAW: Yes.

14 MS. MC FAWN: That's reflected on

15 Exhibit 2 as marked?

16 DR. HORNSHAW: That's correct.

17 MS. MC FAWN: So the only change to

18 Exhibit 2 is the relocation of the word "or"?

19 DR. HORNSHAW: That's correct.

20 MS. ROBINSON: That would conclude the

21 agency's testimony at this time.

22 MR. RAO: Can I have a clarification.

23 About the changes for 742.105, is that change to

24 be made before we go final notice because that's

L.A. REPORTING - (312) 419-9292

1 not part of the docket B.

2 MS. ROBINSON: Right, we'll reflect that

3 in the draft that we send out on Friday through

4 strikouts and underlines.

5 MR. FEINEN: Dr.

Hornshaw, in your

6 testimony, you referred to the April 17th, 1997,

7 order. There's been two orders in docket B. I

8 just want to make it clear on the record that the

9 May 1st order also contains the same language as

10 the April 17th, 1997.

11 Would your testimony be true if we

12 were to make that note, that either/or?

13 MS. MC FAWN: Let me try to clarify. On

14 April 17th, the board proposed for first notice

15 revisions to part 742. The joint committee would

16 not allow us to go to first notice. So on May

17 1st, we reissued those same revisions but not for

18 first notice. It was just for the purposes of

19 docket B and what we could discuss in here.

20 So what Mr.

Feinen's asking you is

21 your testimony refers to our first order which was

22 for first notice, would that remain the same for

23 our order as of May 1st?

24 DR. HORNSHAW: Yes.

L.A. REPORTING - (312) 419-9292

1 MR. FEINEN: One more question. When

2 you're referring to second notice when you're

3 talking about section 915(I), you're referring to

4 second notice in R97-12(A)?

5 DR. HORNSHAW: That's correct.

6 MR. FEINEN: Thank you.

7 MS. MC FAWN: Can I ask you before we go

8 any further, you have before you what's called the

9 draft of agency proposal which is Exhibit 2,

10 marked as Exhibit 2.

11 Does this reflect -- other than the

12 change in the location of the word "or," does this

13 exhibit reflect what the agency would propose for

14 the board concerning the similar-acting

15 chemicals?

16 DR. HORNSHAW: Yes.

17 MS. MC FAWN: So this would reflect what

18 you testified about in your testimony and the

19 revisions you sought?

20 DR. HORNSHAW: Yes.

21 MS. MC FAWN: Thank you.

22 HEARING OFFICER FELTON: Mr.

Hornshaw,

23 do you have anything additional you would like to

24 add in support of the agency's proposal?

L.A. REPORTING - (312) 419-9292

1 DR. HORNSHAW: Not at this time.

2 HEARING OFFICER FELTON: Would anyone

3 else on behalf of the agency like to add anything

4 additional in support of this proposal?

5 MS. ROBINSON: Not at this time.

6 HEARING OFFICER FELTON: At this time

7 would you like to move both Exhibits 1 and 2 into

8 evidence?

9 MS. ROBINSON: Yes, please.

10 HEARING OFFICER FELTON: Are there any

11 objections to moving Exhibit 1, the testimony of

12 Thomas C.

Hornshaw, and Exhibit 2, the draft

13 language of the agency proposal prepared on behalf

14 of the board into evidence at this time?

15 Seeing that there are no

16 objections, we will move both Exhibit 1 and 2 into

17 evidence and into the record of both Thomas C.

18 Hornshaw's testimony and the draft language of the

19 agency proposal prepared on behalf of the board.

20 MS. ROBINSON: Thank you.

21 (Documents received

22 in evidence.)

23 HEARING OFFICER FELTON: We will now

24 proceed with questions for the agency witnesses.

L.A. REPORTING - (312) 419-9292

1 As I previously mentioned, if you have any

2 questions for one of the agency witnesses, please

3 raise your hand and wait for me to acknowledge

4 you. When I acknowledge you, please stand and

5 state in a loud and clear voice your name and the

6 organization you represent, if any. Are there any

7 questions at this time? Question.

8 MR. RIESER: My name is David

Rieser.

9 I'm with the law firm of Ross &

Hardies. I

10 represent the Illinois Steel Group and the

11 Illinois Petroleum Council and I have in all these

12 proceedings. I have a series of questions to

13 ask. Some are with respect to the language that's

14 proposed and some with respect to some of the

15 concepts. We'll start with easy ones which are on

16 the language.

17 Looking at Exhibit 2, I'm looking

18 at page 5 which is 805(c), the language we were

19 just talking about. This language talks about

20 mixtures of similar-acting chemicals. Do you see

21 where I'm referring?

22 DR. HORNSHAW: Yes.

23 MR. RIESER: And would you agree with me

24 there's no definition of a similar-acting chemical

L.A. REPORTING - (312) 419-9292

1 in the rule?

2 DR. HORNSHAW: Other than by having them

3 listed on the tables that define what are -- what

4 are target organ/organ systems or similar effects.

5 MR. RIESER: Right. And there was

6 language which was stricken here in (c) which

7 talks about chemicals which affect the same target

8 organ/organ system or similar mode of action, is

9 that correct?

10 DR. HORNSHAW: That's correct.

11 MR. RIESER: That's what you mean by

12 similar-acting chemicals?

13 DR. HORNSHAW: Yes.

14 MR. RIESER: Would it be acceptable

15 instead of saying similar-acting chemicals to say

16 regarding mixtures of chemical which affect the

17 same target organ/organ system or similar mode of

18 action?

19 DR. HORNSHAW: That would be

20 appropriate.

21 MR. RIESER: Okay. With respect again

22 looking at Exhibit 2 and actually in that same

23 section moving down to 1 sub 2 -- 1 sub 2 on page

24 6, this is language that was in the original --

L.A. REPORTING - (312) 419-9292

1 that's in 97-12(A) in the second notice, it says

2 that, "if the value of the weighted average

3 calculated in accordance with the equations above

4 is greater than 1.0, then additional remediation

5 must be carried out until the level of

6 contaminants remaining in the

remediated area have

7 a weighted average," et cetera. Do you see where

8 I'm referring?

9 DR. HORNSHAW: Yes.

10 MR. RIESER: Is it accurate when it says

11 additional remediation, it may not be necessary to

12 actually do in-site remediation to achieve these

13 values, but that one could use the tiered approach

14 or exclusion of pathways or other methodologies

15 contained in this entire 742 rule to achieve the

16 appropriate remediation objectives at the site?

17 DR. HORNSHAW: That's true.

18 HEARING OFFICER FELTON: Do you have

19 anymore questions at this time?

20 MR. RIESER: Yes, yes. I have a long

21 list of them, and I'm looking for it.

22 HEARING OFFICER FELTON: If you're more

23 comfortable sitting down, that's fine.

24 MR. RIESER: Thank you. Looking at the

L.A. REPORTING - (312) 419-9292

1 language of 805(d), how exactly is that intended

2 to work?

3 DR. HORNSHAW: The way we envisioned

4 this working is if in the investigation for a

5 site, if any chemical which is on the new table

6 which we have created, appendix A, table H, those

7 are carcinogens whose Tier 1 objective exceeds the

8 1 in 1,000,000 target cancer risk, if any of those

9 chemicals are detected during the investigation,

10 then by definition the target or the risk level at

11 the site is greater than the 1 in 1,000,000 target

12 that we generally said should apply at all sites;

13 therefore, that chemical or those chemicals plus

14 any other chemicals detected at the site which

15 affect the same target organ in the body, all of

16 those need to be elevated to a further evaluation

17 of the mixture effects in a Tier 2 evaluation.

18 I'm sorry, I've been corrected, any other

19 chemicals of concern for the site.

20 MR. RIESER: And the evaluation in Tier

21 2 is according to looking at either 805(c) or --

22 the procedures identified in either 805(c) or

23 805(d) as you proposed here, correct?

24 DR. HORNSHAW: Correct.

L.A. REPORTING - (312) 419-9292

1 MR. RIESER: 805(c) is sort of the

2 cumulative effects formula that's sort of been

3 consistent throughout this

rulemaking. It's

4 appeared in several different places, but it

5 includes adding the ratio of the chemical to its

6 Tier 1 cleanup objective together to arrive at an

7 appropriate weighted average that's used to arrive

8 at a cleanup objective for both or all of the

9 mixture of chemicals that you're looking at,

10 correct?

11 DR. HORNSHAW: Right, and that's only

12 for chemicals that exceed the Tier 1 remediation

13 objective.

14 MR. RIESER: Okay.

15 DR. HORNSHAW: The 805(c) part.

16 MR. RIESER: Okay. And that formula was

17 derived from how the agency dealt with issues that

18 arose under 620.615 mixtures, correct?

19 DR. HORNSHAW: Correct.

20 MR. RIESER: So that was the formula the

21 agency came up with to respond to the mixture

22 issues in 620.615?

23 DR. HORNSHAW: Actually the formula was

24 to address mixtures in soil which has nothing to

L.A. REPORTING - (312) 419-9292

1 do with 615.

2 MR. RIESER: Right, but when you were

3 looking to apply 615 in this

rulemaking, this is

4 the formula you arrived at?

5 DR. HORNSHAW: Correct.

6 MR. RIESER: Is it also true that in

7 issues that have arisen under 615 prior to this

8 rulemaking, you also used this formula, this type

9 of formula, to address this formula for mixtures

10 with similar-acting chemicals?

11 DR. HORNSHAW: Yes, unless, for

12 instance, the entire site was addressed by a

13 formal risk assessment and then 620.615 was

14 addressed in the context of the risk assessment

15 which would be a Tier 3 approach.

16 MR. RIESER: Right. And those would be

17 the use of the more formalized health advisories

18 that are provided for in the appendices of 620?

19 DR. HORNSHAW: That is correct.

20 MR. RIESER: 805(d), on the other hand,

21 you're looking at -- is it correct that you're

22 looking at substances which are detected, that are

23 identified detection levels but don't exceed their

24 Tier 1 cleanup objectives for groundwater,

L.A. REPORTING - (312) 419-9292

1 correct?

2 DR. HORNSHAW: It can be that way, yes.

3 MR. RIESER: Well, but it's designed to

4 be that way?

5 DR. HORNSHAW: Yes.

6 MR. RIESER: For a chemical to be

7 reviewed under 805(d), it doesn't have to exceed

8 its Tier 1 level? It's sufficient to exceed its

9 detection level?

10 DR. HORNSHAW: That's correct.

11 MR. RIESER: Just that it's being

12 detected?

13 DR. HORNSHAW: Only a detect. It can

14 be, but it doesn't have to be in

exceedence of the

15 Tier 1 remediation objectives.

16 MR. RIESER: And if it's detected, what

17 you do is you look for all other chemicals that

18 might affect the same target organ based on

19 appendix A, table F, and then identify the

20 cumulative risk and determine if that cumulative

21 risk exceeds one times ten -- one times ten to the

22 minus 4th so 1 in 10,000?

23 DR. HORNSHAW: That's correct.

24 MR. RIESER: How is the cumulative risk

L.A. REPORTING - (312) 419-9292

1 determined in that scenario?

2 DR. HORNSHAW: That can be determined in

3 a couple of ways. In the table in appendix A,

4 table H, we have given the 1 in 1,000,000 risk

5 level. So a person could calculate the actual

6 risk level by a simple ratio of the detected

7 concentration versus the 1 in 1,000,000 risk

8 concentration, or they could take that through a

9 more formal risk assessment approach and actually

10 calculate the risk of the entire mixture given the

11 exposure assumptions that are either default in

12 approach or developed as part of a Tier 3 risk

13 assessment.

14 MR. RIESER: Is there a specific model

15 or process that's been identified in the 742 rule

16 that specifically provides for that second

17 alternative that you just described?

18 DR. HORNSHAW: Not specifically, no.

19 MR. RIESER: Looking at the first

20 alternative that you described where you were

21 adding the ratio, that's the similar formula to

22 that which is in 805(c) except instead of using

23 the Tier 1 objective in the denominator --

24 DR. HORNSHAW: Very good, Dave.

L.A. REPORTING - (312) 419-9292

1 MR. RIESER: I'm working on it.

2 DR. HORNSHAW: I'm impressed.

3 (Laughter.)

4 MR. RIESER: You use the one in a

5 millionth value?

6 DR. HORNSHAW: That's correct. The 1 in

7 1,000,000 cancer risk concentration would be the

8 denominator.

9 MR. RIESER: So by using that formula,

10 however, especially with the 1 in 1,000,000 target

11 risk in the denominator, you may arrive, depending

12 on which chemicals you have that affect the same

13 target organ, at values which are orders of

14 magnitude below the individual Tier 1 groundwater

15 objectives for those individual substances?

16 DR. HORNSHAW: That is a possibility.

17 MR. RIESER: And the purpose of 805(d)

18 is to comply with the statutory direction that you

19 don't have residential standards that are below

20 one in a million? They have target risks below

21 one in a million?

22 DR. HORNSHAW: Could you repeat that.

23 MR. RIESER: The purpose of 805(d) is so

24 that you don't have mixtures of chemicals for a

L.A. REPORTING - (312) 419-9292

1 residential site for drinking water that don't

2 give you a target risk of less than 1 in 1,000,000

3 for the site?

4 DR. HORNSHAW: No, less than 1 in

5 10,000.

6 MR. RIESER: 1 in 10,000, thank you.

7 And the purpose of that is to comply with the

8 statutory directive?

9 DR. HORNSHAW: That's correct.

10 MR. RIESER: Doesn't the statute also

11 say at the 805(d) that no groundwater remediation

12 objective adopted pursuant to the section shall be

13 more restrictive than the applicable Class I or

14 Class III groundwater quality standard adopted by

15 the board?

16 DR. HORNSHAW: Yes.

17 MR. RIESER: So that the statute kind of

18 has both issues, it has -- it can't be less than 1

19 in 10,000, but it also has to be no less

20 restrictive than the groundwater objective?

21 DR. HORNSHAW: I think the statute

22 intended for that to be any individual chemical.

23 I don't think it meant a mixture of chemicals.

24 MR. RIESER: Okay. It doesn't state

L.A. REPORTING - (312) 419-9292

1 mixtures in describing those two things. I think

2 that's accurate. The groundwater -- excuse me,

3 the Tier 1 groundwater cleanup objectives are

4 based almost entirely on the 620 groundwater

5 quality standards, correct?

6 DR. HORNSHAW: For the most part, yes.

7 MR. RIESER: And those are based almost

8 entirely on the maximum contaminant levels

9 developed by the United States Environmental

10 Protection Agency?

11 DR. HORNSHAW: Not necessarily. Mostly,

12 but I wouldn't say almost entirely.

13 MR. RIESER: And the

MCLs, maximum

14 contaminant levels, are not limited by specified

15 target risk, is that correct?

16 DR. HORNSHAW: For carcinogens, the

17 target is 1 in 1,000,000 risk, but that target is

18 tempered by other considerations such as detection

19 limits, natural occurrence, what I've already

20 testified to.

21 MR. RIESER: Okay. But the MCL value,

22 the numbers selected by the USEPA, still reflects

23 their considered opinion as to what's appropriate

24 and safe for drinking water for that -- in

L.A. REPORTING - (312) 419-9292

1 drinking water for that particular substance?

2 DR. HORNSHAW: That's correct, at least

3 at the time it was issued.

4 MR. RIESER: And until that's changed by

5 rulemaking, that remains their opinion?

6 DR. HORNSHAW: Yes.

7 MR. RIESER: If you were just looking at

8 615 -- I'm sorry, 620.615, mixtures of chemicals

9 under 620.615, and you didn't have a statutory

10 directive that you couldn't have a target risk

11 below one times ten and ten to the minus four,

12 would you need 805(d)? Would you need this type

13 of analysis?

14 DR. HORNSHAW: I'm not sure I'm

15 following your question. Could you repeat that.

16 MR. RIESER: Let me ask it a different

17 way. Under -- when you were evaluating mixtures,

18 it's part of your task, your position to evaluate

19 the question of mixture of similar-acting

20 substances at sites under 620.615 on behalf of the

21 agency, correct?

22 DR. HORNSHAW: That's correct.

23 MR. RIESER: If you were doing that task

24 for a site in the absence of the 742

rulemaking,

L.A. REPORTING - (312) 419-9292

1 you would look solely at the type of analysis that

2 is in 805(c) or a more formal risk assessment if

3 that was available for the site, is that correct?

4 DR. HORNSHAW: That's correct, and as an

5 example, if the chemical -- one of the chemicals

6 in a mixture did not have a groundwater quality

7 standard as in 620.410, 410, then we would look to

8 620.615 procedures to establish the denominator to

9 be used, and in most cases for a carcinogen,

10 that's going to be a detection limit. You know,

11 the health advisory for carcinogens in 620.615 is

12 the lowest detection limit of any of the USEPA

13 analytical limits. So it would be a detection

14 limit as the denominator.

15 MR. RIESER: If there was a 410 standard

16 for that substance, then you would use the 410

17 standard in that?

18 DR. HORNSHAW: Yes, that would be the

19 denominator, correct.

20 MR. RIESER: Kind of going back to

21 805(c) and (d) -- I'm sorry, 805(d), if the

22 detection limit, the ADL is greater than the

23 target risk value, then you work from the

24 detection limit, is that correct?

L.A. REPORTING - (312) 419-9292

1 DR. HORNSHAW: That's correct.

2 MR. RIESER: Would you in that

3 circumstance put the detection limit rather than

4 the target risk value in the denominator?

5 DR. HORNSHAW: That's correct.

6 MR. RIESER: Just a minute, please. Let

7 me move on to another area. The agency proposes

8 that the language the board included in what was

9 originally their first notice and apparently is no

10 longer their first notice at 900(f), the move to

11 915 so that the mixtures of substances are

12 considered only in the context of formal risk

13 assessments, is that correct?

14 DR. HORNSHAW: That's correct.

15 MR. RIESER: What was the agency intent

16 on this point?

17 DR. HORNSHAW: We feel that's the

18 appropriate place to consider mixture effects is

19 in the context of a risk assessment.

20 MR. RIESER: Under other features of

21 Tier 3 such as exclusion of pathways, it really is

22 not an issue, is that correct?

23 DR. HORNSHAW: That's correct.

24 MR. RIESER: I have no further

L.A. REPORTING - (312) 419-9292

1 questions.

2 HEARING OFFICER FELTON: Any other

3 questions?

4 MR. FEINEN: I have two follow-up

5 clarification questions based on some of the

6 questions that Mr.

Rieser had for Dr.

Hornshaw.

7 When talking about describing in

8 805(c)(1) (ii), additional remediation, basically

9 what you're talking about when you're talking

10 institutional controls and engineered barriers,

11 you're talking about doing that pursuant to a

12 different tier, Tier 2 or Tier 3? When you're

13 saying you don't have to do any further

14 remediation, you can do institutional control or

15 an engineered barrier pursuant to Tier 2 or

16 Tier 3?

17 DR. HORNSHAW: That could be among the

18 options that could be used to meet the objectives

19 of this section, yes.

20 MR. FEINEN: And in (d) when you're

21 talking about carcinogens detected by different

22 chemicals which exceeded 10 to the minus 6, you

23 need to go to Tier 2?

24 DR. HORNSHAW: Yes.

L.A. REPORTING - (312) 419-9292

1 MR. FEINEN: Could you also go to

2 Tier 3?

3 DR. HORNSHAW: Yes, you could,

4 certainly.

5 MR. FEINEN: That's all I have.

6 HEARING OFFICER FELTON: Any other

7 additional questions?

8 MR. RAO: I have some questions.

9 HEARING OFFICER FELTON: Please proceed,

10 Mr.

Rao.

11 MR. RAO: Dr.

Hornshaw, in discussing

12 the similar-acting substances in soil remediation

13 objectives under Tier 1, you said that because of

14 the inherently conservative nature of the

15 remediation objectives that you don't need to

16 consider the effects of similar-acting

17 substances.

18 Can you explain how it's different

19 under Tier 2 for soil remediation objectives if

20 somebody's using the SSL procedure in the Tier 2,

21 you know, does the conservative nature changes in

22 Tier 2 to Tier 1?

23 DR. HORNSHAW: It's less conservative in

24 that we're not making assumptions that are

L.A. REPORTING - (312) 419-9292

1 protective of greater than 95 percent of the

2 entire country in Tier 2. In Tier 2 you're making

3 consideration of site specific factors that should

4 still be protective, but the extra layer of

5 conservatism is not there anymore.

6 MR. RAO: Because in your earlier

7 testimony in docket A, you were saying that, you

8 know, essentially both were in a -- the procedure

9 for SSL was essentially the same except for the

10 site specific numbers that they were going to use

11 in the equations, all the safety factors built in

12 are still the same. So just curious, you know,

13 how it changes.

14 DR. HORNSHAW: I think we said equally

15 protective. I don't think we ever said equally

16 conservative.

17 MR. RAO: Do any of the safety factors,

18 whatever that you talk about, inherently

19 conservative, when you say it, does it change

20 other than those parameters listed in one of the

21 tables that they can get it using site specific

22 numbers?

23 DR. HORNSHAW: Could you repeat that?

24 MR. RAO: Yeah. You see, what I'm

L.A. REPORTING - (312) 419-9292

1 trying to get at is they're using the same

2 equations. If they use the default numbers,

3 they're supposed to get the Tier 1 numbers?

4 DR. HORNSHAW: That's correct, right.

5 MR. RAO: So if they use site specific

6 numbers, how does it change the conservative

7 nature of the remediation objective?

8 DR. HORNSHAW: I guess I can answer that

9 by giving an example. When you're considering

10 transport of the chemicals from soil to the point

11 of exposure, one of the key assumptions is the

12 amount of organic carbon which is in the soil to

13 retard that transport, and it is conservatively

14 assumed in Tier 1 that there's less than one

15 percent organic carbon in the soil.

16 The specific value is .6 for

17 surface soils and .2 percent for subsurface soils,

18 when in reality most soils are greater than one

19 percent, and if you plug in the site specific

20 value into the calculation, you get a number

21 that's quite a bit different from the Tier 1

22 lookup value, at least for the chemical -- the

23 pathways that have a migration component to them.

24 You know, the direct ingestion

L.A. REPORTING - (312) 419-9292

1 pathway, there's no difference because there's no

2 transport. You are just eating the soil straight

3 up. That's an example where there's additional

4 conservatism in the Tier 1 number that is no

5 longer -- it's replaced by site specific data in

6 the Tier 2 evaluation.

7 MR. RAO: Okay. I have one more

8 question.

9 DR. HORNSHAW: And I might add, you

10 don't have that level of conservatism in the Tier

11 1 value for groundwater because you don't have the

12 transport. We are assuming that a person is

13 drinking that water directly the same as if

14 they're eating the soil directly.

15 MR. RAO: On going to your proposed

16 changes under 742.505(b)(3)(A), under these

17 proposed changes, are you saying that for Tier 1

18 groundwater objectives, that the effect of

19 mixtures of similar-acting substances which are

20 noncarcinogens may not be considered under Tier

21 1?

22 Because the way it's proposed, you

23 say if the Tier 1 groundwater remediation

24 objective listed in table -- appendix B, table E

L.A. REPORTING - (312) 419-9292

1 is not exceeded, you know, 620.615 requirements

2 are met. So if you have carcinogen --

3 noncarcinogens like ethyl benzene and toluene,

4 which are at their remediation objectives, then

5 they still exceed the hazard index of one, but

6 according to what you propose, you know, they met

7 the 620.615 requirements.

8 DR. HORNSHAW: We've agreed with the

9 advisory committee that there is enough

10 conservatism built into the development of the

11 Tier 1 remediation objectives, other than for

12 those chemicals that already exceed the 1 in

13 1,000,000 risk level, that we're not going to look

14 at the effect of mixtures in Tier 1.

15 MR. RAO: So basically what you're

16 saying is in Tier 1 for groundwater, you are going

17 to look at only for carcinogens, you know, which

18 are higher than one in a million cancer risk,

19 right, and you're not going to consider

20 noncarcinogens under Tier 1?

21 DR. HORNSHAW: If they exceed the Tier 1

22 remediation objective, any chemical exceeds, then

23 that chemical, plus any other chemical that

24 affects the same target, get elevated to a Tier 2

L.A. REPORTING - (312) 419-9292

1 evaluation to make sure that the mixture effect is

2 not of concern.

3 MS. MC FAWN: Just so I understand, so

4 you are saying that under Tier 1, you want the

5 board to consider

noncarcinogenic ones as well as

6 carcinogenic ones?

7 DR. HORNSHAW: If they exceed the Tier 1

8 remediation objective, yes, then that chemical

9 plus any others that affect the same target go to

10 a Tier 2 evaluation for groundwater.

11 MS. MC FAWN: Yes, I was talking

12 groundwater as well.

13 MR. FEINEN: So what you're saying,

14 Dr.

Hornshaw, is that for a

noncarcinogen, you

15 don't look at the cumulative effects until it

16 exceeds its Tier 1 number?

17 DR. HORNSHAW: That's correct.

18 MR. FEINEN: And then if it does exceed

19 its Tier 1 number, you look to see if there's any

20 other chemicals that similarly act and then it

21 gets kicked into Tier 2?

22 DR. HORNSHAW: That's correct.

23 MS. MC FAWN: So you only get to the

24 additivity question if it exceeds?

L.A. REPORTING - (312) 419-9292

1 DR. HORNSHAW: Right.

2 MS. HENNESSEY: Would you be kicked out

3 of Tier 1 if it didn't meet the Tier 1 groundwater

4 objective anyway?

5 DR. HORNSHAW: No. I think they would

6 be allowed to do other things or try to

remediate

7 to the objective for that chemical only.

8 MS. HENNESSEY: I see.

9 DR. HORNSHAW: But if there's other

10 chemicals that affect the same target, then all of

11 those chemicals go to another level of evaluation

12 to make sure that the mixture of chemicals is not

13 unacceptable.

14 HEARING OFFICER FELTON: Mr.

Rieser.

15 MR. RIESER: Dr.

Hornshaw, when you

16 talked about the

conservatisms that are built into

17 the

noncarcinogenic values, can you give us an

18 example of the levels of conservatism that you're

19 talking about.

20 DR. HORNSHAW: This wasn't discussed a

21 whole lot in the meeting with the advisory

22 committee, but the way the maximum contaminant

23 levels for

noncarcinogens is developed is similar

24 to the approach that we have for health advisories

L.A. REPORTING - (312) 419-9292

1 for

noncarcinogens in that there's consideration

2 given to relative source contribution, which

3 accounts for exposure to a chemical from other

4 sources than drinking water, and so that factor is

5 kind of built in as a level of conservatism so

6 that the amount that's allowable in drinking water

7 is usually less than the hazard index of one to

8 account for other exposures during a person's

9 daily activities, work, home, whatever.

10 So there is that level of

11 conservatism built in. There aren't levels of

12 conservatism built in for transport, as I

13 discussed, because we're assuming the person is

14 exposed directly.

15 MR. RIESER: There are also levels of

16 conservatism built into that value based on the

17 assumption that a person is of a certain weight

18 and is drinking a certain quantity of water per

19 day over a certain period of years, 30, 40 years,

20 is that correct?

21 DR. HORNSHAW: 30 years or 70 years. It

22 depends on when the MCL was issued.

23 MR. RIESER: That's also an example of

24 some of the conservatism that's in those values?

L.A. REPORTING - (312) 419-9292

1 DR. HORNSHAW: That's correct.

2 MR. RAO: Those things don't change in

3 Tier 2, also, right?

4 DR. HORNSHAW: No, they don't. Those

5 are built into the process all the way through,

6 and a similar statement could be made for the

7 toxicity data themselves. Those

conservatisms are

8 there for all chemicals, all tiers.

9 HEARING OFFICER FELTON: Are there any

10 further questions at this time?

11 MS. HENNESSEY: I have a couple.

12 HEARING OFFICER FELTON: Sure.

13 MS. HENNESSEY: Dr.

Hornshaw, I have a

14 question on 742.915(h). The first sentence of the

15 agency's proposed language reads, quote, "The

16 contaminants of concern which affect the same

17 target organ/organ system or similar mode of

18 action shall be specifically addressed." Can you

19 expand on how that is to be addressed.

20 DR. HORNSHAW: There is guidance in

21 USEPA documents for conducting risk assessments at

22 Super Fund sites, for instance, that tell the

23 responsible party how to address mixture of the

24 carcinogens. Typically, you would -- well,

L.A. REPORTING - (312) 419-9292

1 carcinogens and

noncarcinogens, you would go

2 through some evaluation of exposure through all

3 routes and then sum up the total exposure and then

4 compare that against the acceptable exposure, and

5 for mixtures, those similar effects are just

6 added.

7 So if you've got two chemicals that

8 affect the liver, for instance, you would evaluate

9 the exposure to that chemical through all routes

10 that are relevant at a site, do the same thing for

11 the second chemical, and you would develop either

12 a hazard index based on comparison of the total

13 exposure to the acceptable exposure, do the same

14 thing for the second chemical, and then you just

15 add the hazard index or overall hazard quotient,

16 and if it's a

noncarcinogen, after you've added

17 those values, still less than 1.0, then the

18 mixture is acceptable, and similarly for

19 carcinogens, if the total risk is greater than one

20 in a million, then you have a situation that needs

21 to be evaluated further.

22 MS. HENNESSEY: Okay. So in any event,

23 under this section 742.915(h), the risk is going

24 to be quantified?

L.A. REPORTING - (312) 419-9292

1 DR. HORNSHAW: Oh, yes. We would fully

2 expect that in a formal risk assessment.

3 MS. HENNESSEY: Okay. A question on 805

4 -- I guess 505(b) as well as 805(c) and (d), you

5 used the phrase, the requirements of section

6 620.615, and specified when those are met.

7 Just for clarification, do I

8 understand this to mean that if you look at

9 620.615(b), it refers you to procedures set forth

10 in appendices A, B and C of part 620.

11 DR. HORNSHAW: I'm sorry, I'm at 615.

12 What exactly are you referring to?

13 MS. HENNESSEY: 620.615(b) says that, if

14 there are mixtures of similarly-acting chemical

15 substances, you evaluate them according to the

16 procedure set forth in appendices A, B and C of

17 part 620?

18 DR. HORNSHAW: Correct.

19 MS. HENNESSEY: Okay. And the language

20 that you proposed for 742 in these various spots,

21 505 and 805, would substitute the procedures in

22 742 for the procedures set forth in appendices A,

23 B and C of part 620?

24 DR. HORNSHAW: Yes. We envision that

L.A. REPORTING - (312) 419-9292

1 everything that we put in 742 would satisfy the

2 requirements of 615(a) where it just says, "The

3 need for additional health advice shall be

4 determined by the agency," and in the context of

5 742, this is how we're determining it.

6 MS. HENNESSEY: Okay. What is the

7 effect of the language you proposed on

8 620.615(b)?

9 DR. HORNSHAW: I guess it kind of

10 supplants that.

11 MS. HENNESSEY: Okay.

12 HEARING OFFICER FELTON: Are there any

13 additional questions. Mr.

Feinen?

14 MR. FEINEN: Just a clarification. In

15 responding to one of Ms.

Hennessey's questions,

16 you mentioned some guidance documents by USEPA.

17 I'm wondering if those guidance documents are

18 incorporated by 97-12(A).

19 DR. HORNSHAW: Yes, they are, Risk

20 Assessment Guidance for Super Fund and Exposure

21 Factors Handbook, and I think there's -- there may

22 be others. There are two specifically in there

23 that give guidance on how that's to be done.

24 MR. FEINEN: Thank you.

L.A. REPORTING - (312) 419-9292

1 MS. HENNESSEY: Just one grammatical

2 question, 742.505(d), both sentences start out,

3 "sites which do not meet." Would it be more

4 appropriate to say that the language would be,

5 "sites that do not meet"?

6 DR. HORNSHAW: I believe so, yes.

7 MS. HENNESSEY: Okay. I just took a

8 grammar seminar, sorry. I don't have anything

9 else.

10 HEARING OFFICER FELTON: Board Member

11 Hennessey, you were referring to 505(b)(4)?

12 MS. HENNESSEY: That's correct, yes.

13 HEARING OFFICER FELTON: Thank you. Are

14 there any other additional questions at this

15 time?

16 MS. MC FAWN: Why don't we take a break

17 and go.

18 HEARING OFFICER FELTON: Take a brief

19 10-minute break. We will

readjourn at about

20 11:30.

21 (Recess taken.)

22 HEARING OFFICER FELTON: Back on the

23 record. Are there any further questions for the

24 agency at this time? Seeing none, as we have

L.A. REPORTING - (312) 419-9292

1 completed earlier -- actually one follow-up

2 question or one comment I want to make is would

3 anyone today like to testify in support or in

4 opposition to this

rulemaking?

5 As we have ended or come to a close

6 of this, it appears that we will not need the

7 hearing scheduled for tomorrow. So that hearing

8 is canceled. Please note that the second hearing

9 for this proposed rule in docket B has been

10 scheduled and will proceed on Thursday, May 29th,

11 1997, in Springfield at 10:00 a.m. in the Lincoln

12 room in the Stratton Building.

13 The hearing may be continued on the

14 record to Friday, May 30th, 1997, at that same

15 time in a location necessary to accommodate any

16 questions or additional testimony that provides

17 us. Excuse me, that would be the

Howlett

18 Building. Is there anyone at this time that knows

19 that they will be testifying at the May 29th

20 hearing? And if so, just let us know at this

21 time. Does anyone anticipate that they will be

22 testifying next week?

23 Please note that if you are

24 testifying or if you would like to submit

prefiled

L.A. REPORTING - (312) 419-9292

1 testimony, pursuant to my hearing officer order

2 dated May 2nd, 1997, all other testimony that

3 would be

prefiled must be filed by May 23rd,

4 1997. There's no requirement to

prefile testimony

5 for the May 29th, 1997, hearing, and this will not

6 preclude you if you fail to testify at that time.

7 The mailbox will set forth 35 Illinois

8 Administrative Code 101. 102(d) will not apply to

9 these filings.

10 Are there any other matters that

11 need to be addressed at this time? We would like

12 to note at this time that the agency will not be

13 at this time preparing a draft or a language draft

14 proposal of the rules. We will be relying at this

15 time on Exhibit 2. If that changes at the second

16 hearing, we will address that issue at that time.

17 MS. HENNESSEY: That would be Exhibit 2

18 as corrected by Dr.

Hornshaw's testimony?

19 HEARING OFFICER FELTON: Correct.

20 Seeing that there are no other further questions

21 at this time, I would like to thank everyone for

22 being prepared for this first hearing, and this

L.A. REPORTING - (312) 419-9292

1 hearing is hereby adjourned. We look forward to

2 seeing you all in Springfield on May 29th. Thank

3 you.

4 (Which were all the proceedings

5 had in the above-entitled case.)

L.A. REPORTING - (312) 419-9292

1 ILLINOIS POLLUTION CONTROL BOARD

3 LISA H. BREITER, CSR, RPR, CRR, being

4 first duly sworn, on oath says that she is a court

5 reporter doing business in the City of Chicago;

6 that she reported in shorthand the proceedings at

7 the taking of said hearing and that the foregoing

8 is a true and correct transcript of her shorthand

9 notes so taken as aforesaid, and contains all of

10 the proceedings had at said hearing.

LISA H. BREITER, CSR, RPR, CRR

L.A. REPORTING

79 West Monroe Street

16 Suite 1219

Chicago, Illinois 60603

17 (312) 419-9292

(312) 419-9294 Fax

18 License No. 84-003155

L.A. REPORTING - (312) 419-9292