0001

ILLINOIS POLLUTION CONTROL BOARD

2 IN THE MATTER OF:

)

3 WATER QUALITY STANDARDS AND ) R08-09

EFFLUENT LIMITATIONS FOR THE ) (Rulemaking-

4 CHICAGO AREA WATERWAY SYSTEM ) Water)

AND THE LOWER DES PLAINES )

5 RIVER: PROPOSED AMENDMENTS )

TO 35 Ill. Adm. Code Parts )

6 301, 302, 303 and 304

)

REPORT OF PROCEEDINGS held in the

8 above-entitled cause before Hearing Officer Marie

9 Tipsord, called by the Illinois Pollution Control

10 Board, taken before Laura Mukahirn, CSR, a notary

11 public within and for the County of Cook and State

12 of Illinois, at the Thompson Building, 100 West

13 Randolph, Chicago, Illinois, on the 10th day of

14 September, 2008, commencing at the hour of 1:00 p.m.

0002

A P P E A R A N C E S

MS. MARIE TIPSORD, Hearing Officer

MR. TANNER GIRARD, Acting Chairman

MR. ANAND RAO

MR. NICHOLS MELAS

Appearing on behalf of the Illinois

Pollution Control Board

ILLINOIS ENVIRONMENTAL PROTECTION AGENCY

1021 North Grand Avenue East

P.O. Box 19276

Springfield, Illinois 62794-9276

(217)782-5544

BY: MS. DEBORAH WILLIAMS

MS. STEPHANIE DIERS

MR. ROBERT SULSKI

MR. SCOTT TWAIT

MR. HOWARD ESSIG

BARNES & THORNBURG

One North Wacker Drive

Suite 4400

Chicago, Illinois 6606-2833

(312)357-1313

BY: MR. FREDRIC P. ANDES

Appearing on behalf of the Metropolitan

Water Reclamation District

0003

HEARING OFFICER TIPSORD: Good

afternoon. I hope everyone had a nice lunch.

And I believe we are ready to turn to the

IEPA's questions. There are prefiled

questions for -- we finished with

Dr. Petropoulou, so we're ready for Dr. Gerba

or Dr. Tolson.

MS. DIERS: Dr. Gerba, I'm going to

start with Question 3 of our prefiled

questions. On Page 2 of your prefiled

testimony you state, the indicators selected

are those which have been traditionally used

and those recommended by the United States

Environmental Protection Agency and the World

Health Organization for assessment of

recreational water quality, NRC 2004.

First, could you please

explain which organisms were chosen because

they were traditionally used?

DR. GERBA: Okay. On our list

judicial ones would be fecal coliforms, E.

Coli, enterococci. Some European countries

actually have used salmonella as an indicator

in recreational water quality and viruss.

0004

MS. DIERS: And the next question,

which organisms were chosen because they were

recommended by U.S. EPA for assessment of

recreational water qualities?

DR. GERBA: Basically enterococci and

E. Coli, although fecal coliforms have been

used, of course.

MS. DIERS: And which organisms were

chosen because they were recommended by WHO

for assessment of recreational water quality?

DR. GERBA: The World Health

Organization recommends a number of organisms

and criteria and for potentially selection of

different organisms. But fecal coliforms,

E. Coli, and enterococci are also on that

list.

MS. DIERS: I'm going to jump down to

No. 6.

MR. ETTINGER: May I ask one question

about that? Do you like any of those

indicators?

DR. GERBA: Do I like them?

MR. ETTINGER: Yeah. Do you think any

of them are -- indicate whether pathogens are

0005

present or not?

DR. GERBA: No. There's no -- I mean

many studies have shown there's really no

direct correlation between the various

pathogens, particularly the viruss, I should

say, and the protozoa and parasites and the

indicators. That's -- the traditional ones I

mentioned, the fecal coliform, the E. Coli

and enterococci. It's one of the reasons

pathogens were actually done as part of this

study.

MR. ETTINGER: So are you aware of any

indicator that you would use?

DR. GERBA: There's pluses and minuses

to use of any indicator, but one of the big

problems with any of the indicators currently

in common use is they don't necessarily

relate to the occurrence of various pathogens

in the water. For example, if I chlorinated

sewage effluence, cryptosporidium or Giardia

are fairly resistant to chlorination. These

indicators are not. So it's hard to

establish a correlation with it. If I used

UV light -- adenovirus, they're resistant to

0006

UV light where the bacterial indicators are

very susceptible. So you can have situation

with hardly any indicators with a lot of

pathogens.

MR. ETTINGER: And I think you said

none of the traditional indicators, they all

have problems -- are there any -- I'm

sorry -- untraditional indicators that you

like better, or is there anything you would

use other than correctly measuring pathogens?

DR. GERBA: I think in the future a

combination of actually looking for certain

pathogens which might create the greatest

risk that some of my colleagues propose using

adenoviruses because they're in greater

abundance than a lot of the other water-born

pathogens, particularly the enteric viruss.

Other people in the past have even suggested

enteroviruses as better indicator of the

risk. To give you -- bacteroides has been

suggested, another bacterial group, anaerobic

bacteria that occurred in the human gut, for

example, and other types of anaerobic

bacteria have been suggested as potential

0007

better indicators because they're more

associated with fecal pollution; and some of

them, more specifically, with human

intestinal tract, an indicator of human fecal

pollution. And they've also been suggested

and studied a lot. But, unfortunately,

they're anaerobic organisms and are more

difficult to work with. Bacteriophages have

been suggested and coliphages which are

bacterial viruses have also been suggested as

indicators of the recreational water quality.

MR. ETTINGER: Independent of what has

been suggested, is there any of them that you

like? If you were stuck with some sort of

indicators, are there any of them that you

like?

DR. GERBA: You know, not that I can

really pick out without -- you know, not

offhand I couldn't really say, pick one.

MR. ETTINGER: Thank you.

MS. DIERS: As I said, I'm going to go

to Question 6 on the prefiled questions. On

Page 4 of your prefiled testimony, you state

that levels of pathogens found in the CAWS

0008

were equal to or lower than values you have

observed in other places with both

disinfected and undisinfected effluents. Is

it your professional opinion that the common

practice of effluent disinfection at

wastewater treatment plants in the United

States is unwarranted based on the science?

DR. GERBA: I think that's really a

policy and management question rather than a

science question.

MS. DIERS: Okay. Question 7: On

Page 5 of your prefiled testimony, you state

that disinfection is warranted in situations

where direct human contact in the immediate

vicinity of an outfall is possible or where

effluent is discharged to areas involving the

production of human food. And I believe you

answered our first one. So I'm going to ask,

what do you mean by areas involving the

production of human food?

DR. GERBA: I think I covered that. I

was talking about shellfish in the marine

environment.

MS. DIERS: Is that all, just the

0009

shellfish?

DR. GERBA: Yeah. Because shellfish

concentrate viruses, and particularly viruses

from the -- maybe 1,000 times above levels

you find in the ambient environment. So they

are a particular issue.

Other types of seafood

could -- and also consumed raw by a lot of

people. That's the other consumer -- other

types of seafoods are usually cooked.

HEARING OFFICER TIPSORD: If I may,

Dr. Gerba, what about water that might then

be used for irrigation, would that be --

DR. GERBA: Do I think it should be

disinfected?

HEARING OFFICER TIPSORD: Yes.

DR. GERBA: If it's food crops,

definitely. And that's a decision in the

United States by the individual states. In

California, I believe it -- or maybe not.

You don't disinfect -- you don't have to

disinfect the sewage effluent if it's

nonhuman food crops that are being irrigated.

And that's done in practice in California.

0010

But if it's human food crops, not only should

it be disinfected, but it also should be

given tertiary treatment and filtered. There

are a lot of steps before -- The situations

where I've seen that done, usually it's

advanced tertiary treatment using -- going

through ultrafiltration membranes and that.

The assurance here is because it's going to

be used for human consumption has to be very

high that there's no pathogens. And

oftentimes pathogen levels are monitored in

the at least the initial phases of those

types of situations.

HEARING OFFICER TIPSORD: And, to your

knowledge, there's no shellfish or use of

CAWS waterway system for irrigation; is that

correct?

DR. GERBA: No, not that I'm aware of.

MS. DIERS: Question 8: You state

that it is not clear that wastewater

disinfection always yields improved effluent

or receiving water quality. Is it your

testimony that disinfection should only be

required when it is demonstrated to yield

0011

water quality improvements?

DR. GERDA: It depends on the

objectives on what the water is going to be

used for and the impact. That's really, I

think, more management decisions, because it

depends on how the water is going to be used

in discharge or what impact might be to the

users of that water and how that impact takes

place.

MS. DIERS: Based on your -- this is

Question 9. Based on your experience, do you

have an opinion one way or another what

indicator organism or organisms would you

recommend to U.S. EPA to use in the

establishment of water quality criteria for

the protection of primary and secondary

contact recreational activities?

DR. GERBA: I really don't have an

opinion on that right now which one might be

better than another.

MS. DIERS: And my last one is

Question 11: Page 5 of your prefiled

testimony you state, therefore, it is

uncertain if disinfection designed to remove

0012

indicators can be effective in the removal of

pathogens and in the reduction of pathogen

risk. Could you please explain what you mean

by this statement?

DR. GERBA: Yes. One example would be

cryptosporidium, and the levels of chlorine

usually apply in a lot of wastewater

treatment plants I've seen. It would have no

effect on the cryptosporidium because it's so

resistant to chlorine. In fact, a lot of the

outbreaks we see in swimming pools today are

due to cryptosporidium because it can

tolerate the one, three and four milligrams

per liter of chlorine that are in swimming

pools. So that would be one example. If we

go to ultraviolet light, certainly in our own

research and others, using UV light systems

for disinfection wastewater, you'll find a

lot more adenoviruses being released into the

environment than would be if you were using

chlorine. So, yeah, you'd have a situation

where you would almost -- you certainly could

meet standards, and other people have shown

this, and still have a lot of adenoviruses

0013

being present in the water because they're so

resistant to ultraviolet light.

MS. DIERS: I think that's all I have

for Dr. Gerba.

HEARING OFFICER TIPSORD: Let's move

to your questions for Dr. Tolson.

MS. WILLIAMS: Okay. Dr. Tolson, I

think it might have been Mr. Gerba who said

earlier that low is a relative term. So I'm

going to ask you a couple of questions about

your use of the word low. You conclude -- in

Question No. 2 for you it says you conclude

that risk for gastrointestinal illness

associated with recreational use of the

Chicago area waterway are low. So can you

tell us what would be a high rate, high risk

of illness, high rate of risk of illness?

Sorry.

DR. TOLSON: Dr. Gerba is right. It

is a relevant term. And the benchmark we use

to sort of set that is the acceptable risk

for primary contact recreation of eight per

1,000.

MS. WILLIAMS: So you rely on the

0014

eight per 1,000 in the U.S. EPA 1986 National

Criteria Document as a dividing line between

low and high or acceptable and unacceptable?

DR. TOLSON: No. We're not saying

anything about that particular standard.

What we're just saying is that here is a

number, and you put that number in

perspective. We're comparing it to this

screening standard, this number that's out

there just to give the reader a sense for

where that would fall within risks that are

otherwise reported.

MS. WILLIAMS: So it's low relative to

eight, the numbers you counted --

DR. TOLSON: And four and, yeah, and

six.

MS. WILHITE: So it's low -- I guess

that's my question. Would six be low?

DR. TOLSON: In order to -- either I

could report the number as two, or I could

put it in context of it's a high or low. And

to put in context of high or low, you need to

come up with a threshold, and there's not

many out there. One of them is the

0015

U.S. EPA primary which is the lowest that EPA

has come out with of 8 per thousand. So it's

low relative to that number.

MS. WILLIAMS: I have some other

questions related to that, but I guess I'll

go in order for now.

No. 3, you also conclude that the

risks associated with recreational use of the

CAWS are mainly due to secondarily loading of

the waterway under wet weather conditions

from CSOs and other dischargers, unquote.

What do you base this conclusion mainly on?

MR. ANDES: Can I clarify something?

On that -- That's a conclusion for the whole

report, so.

MS. WILLIAMS: But it's quoted from

his testimony. That's where the quote is

from.

MR. ANDES: I'm just trying to figure

out. You could say he bases it on everything

in the report --

MS. WILLIAMS: What in the report does

he base it on?

DR. TOLSON: We've covered a lot of

0016

this previously. But I think if you look at

Exhibit 71, Table 5.9 as a summary result

table, and I believe this was actually in my

prefiled testimony also as Exhibit 1. I'm

sorry. It was not. But it's in the report.

And this shows risk from dry weather and

combined dry/wet weather.

MS. WILLIAMS: 5-9? Am I looking at

the wrong thing?

DR. TOLSON: Let me change that. I'm

sorry. I had the wrong one. Let's go with

5-14. Because that shows disinfection versus

nondisinfection. So Exhibit 71, Table 5-14.

And there it shows, for example, North Side

we have a 1.53 illnesses per 1,000 or 15 per

10,000 or 153 per 100,000. And compare that

to including disinfection by, for example, UV

which was the most efficacious in this case

was 1.32 per 1,000.

MS. WILLIAMS: So it was the

difference between the risks that you

calculate for undisinfected versus

disinfected that you base the statement on

primarily?

0017

DR. TOLSON: That was the whole goal

of the study, and that's the essence of the

results are there is a decrease, but the

decrease is minor because of major

contributors to the waterway are other

sources other than the effluent from the

wastewater treatment plants.

HEARING OFFICER TIPSORD: Off the

record for a second.

(Off the record.)

HEARING OFFICER TIPSORD: Back on the

record.

MR. ETTINGER: Let me ask one

question. Did you calculate what the risk

would be to swimmers?

DR. TOLSON: No. Swimmers was not an

intake and ingestion rate scenario for which

we developed any risk numbers.

MR. ETTINGER: Is it safe to swim

there?

DR. TOLSON: We have no basis to make

any assumption.

MS. WILLIAMS: Could you calculate

what the risk to swimmers would be?

0018

DR. TOLSON: I can calculate a lot of

things, yes. There are going to be inherent

uncertainties associated with that that will

probably be greater than the uncertainties

associated with the recreational use for

which we have a considerable amount of

background data on.

MR. ANDES: My objection is swimming

isn't even part of the proposed uses here,

so.

MR. ETTINGER: Well, we might want to

reform the proposal since it seems so safe to

go in there, you know. In fact, we may want

to move that maybe next week.

MR. ANDES: Can't wait.

MR. ETTINGER: Can we take our

canoeing numbers that are on 5-4 and use an

exposure based on swimming and come out with

numbers?

DR. TOLSON: We have not performed any

of those calculations, and I can't really

even speculate on what the result would be.

MR. ETTINGER: If I wanted to do that,

could I just basically take this table of 5.4

0019

and use the exposures that are for swimming

as opposed to the ones for canoeing and come

out with that number?

DR. TOLSON: It's not quite that

simple. You would have to actually go

through the Monte Carlo simulations with

different input assumptions for not only the

ingestion rates for swimming, but also how

long someone swims and --

MS. WILLIAMS: Well, I think this sort

of goes to my next question. I ask in the

next question how did we come up with the

estimated doses for each activity in this

table -- I mean they're listed in the table

that Albert is referring to, right, 5-4? And

you have them in terms of milliliter per

hour.

DR. TOLSON: Yes. We've gone over --

MS. WILLIAMS: I understand, and you

may have answered some of these. I think my

questions are very general, so don't feel

that you have to give a lot of specifics.

But I would like to -- you to answer

generally where these came from the

0020

literature or did you make them up? Can you

tell me where these came from? Maybe I

should understand that from having listened

to your testimony already, but I don't, so.

DR. TOLSON: We did actually spend

quite a lot of time going through how we

derived these ingestion rates.

MR. ANDES: They weren't made up. I

think we can --

MS. WILLIAMS: Do you think this has

been asked and answered? I don't feel that I

understand the answer, so.

HEARING OFFICER TIPSORD: Could you

give us just a --

DR. TOLSON: Okay. I'll give you

another summary. For example, for canoeing,

there are assumptions that one needs to make

on the ingestion rate. What we're looking at

what that range would be for those ingestion

rate numbers, we have to say, well, what's --

what is -- let me back up.

HEARING OFFICER TIPSORD: Excuse me,

Dr. Tolson. I don't mean to interrupt you,

but I think perhaps you just started with

0021

what Miss Williams is getting at. You said

there are assumptions that have to be made.

Are those assumptions from -- how did those

assumptions, how were those assumptions made?

DR. TOLSON: Right. So it's the

assumptions are that the range of the inputs

there. And then once --

MS. WILLIAMS: So you made them up?

DR. TOLSON: One assumption is that --

Let me say this. One assumption is the

ingestion rates vary over a range, and that

they probably don't vary with the symmetrical

distribution. In other words, the center,

the most likely ingestion rate is probably

not the center of that. There's probably

some people that get much more, and those

would happen less frequently. So you'd get a

nonnormally distributed distribution of

ingestion rates. So we have a lognormal

distribution there. Then we have to sort of

ground truth that to what we understand about

literature citations for ingestion. So you

look at things like, well, on those high end

exposures, how bad can they be? We looked at

0022

the U.S. EPA's swimming data or ingestion

rates under that activity and said, you're

probably not going to canoe down the river by

holding onto the canoe and swimming down. So

that's actually the concentration, the

ingestion rates that we assumed for those

high-end exposures. They were way out there

on the tail.

MS. WILLIAMS: So if we wanted to see

another line in your table that said

swimming, milliliters per hour, could we find

that directly from U.S. EPA?

DR. TOLSON: U.S. EPA has actually got

a number of very good studies on swimming and

ingestion rates. They come from pool

exposures where we've got a great tracer,

cyuranic acid, which is the chlorine

stabilizer. And they put a bunch of kids in

the pool and then you can measure their pee.

And you can find out how much they drank by

how much cyuranic acid comes out on the other

end. And we find that EPA sort of uses a

15 mls per event as a swimming exposure.

There are other literature that

0023

cites some other numbers, but that's pretty

typical is 15 mls per event. Now we derived

ours as per hour. So if you look at a

high-end exposure of, say, 20, and you assume

that there's going to be there for three

hours, that gives about 60 mls per event

which is actually higher than the swimming

ingestion assumed by EPA as a point estimate.

MS. WILLIAMS: But event means to them

an event of ingesting water or no? It

doesn't mean a time of going swimming. It

means a time of --

DR. TOLSON: Right, right.

MS. WILLIAMS: -- accidentally --

DR. TOLSON: Typically it's event

driven. So if you were out there for eight

hours, you may have gotten that entire 50 mls

on five minutes within that, or it could have

been disbursed out along -- they don't care

about that. They just do it per event. Here

we're doing it per hour, and we're also

incorporating a time aspect because we

realize that the different recreational

activities are different in the amount of

0024

time that people spend with the water.

MS. WILLIAMS: Did you want to follow

up, Albert, or were you just clearing your

throat?

MR. ETTINGER: I was just clearing my

throat. I'm writing the new petition.

MS. WILLIAMS: So in deriving these

numbers in Table 5-4, what assumptions were

made regarding how frequently canoers or

hand-powered boaters would capsize? I mean

how did --

DR. TOLSON: So we didn't really

corporate any of that. This is a

distribution of exposures that goes to

high-end activities. Those people that we

categorize from the UAA as having higher

contacts, which includes the canoers, which

is our representative sort of perceptor. The

distribution is a continuum. There are some

people that, on their event, they consume 30,

there are some that are going to consume 32,

some 50, some 20, and some 1. There's a

whole continuum of what's going to happen out

there. We don't say that we've got a

0025

capsized person or a noncapsized person and

then define them in one group or another.

Somebody may capsize and actually ingest very

little. Others may not capsize and ingest

much more.

MR. ETTINGER: Are there --

MS. WILLIAMS: Well, I'm just trying

to understand then is if the person who

capsized and ingested quite a bit, you would

assume that would be somewhere in the 50

milliliter per event range, correct?

DR. TOLSON: I would not assume that.

I -- actually, we have no data on how much

people ingest when they capsize. My

speculation is that when you capsize, you're

probably going to ingest some water. And we

wanted to try to capture that within the

continuum, the full distribution of what's

out there. The way that we did that is we

said here is some data on swimming, an

activity where people are immersed. Let's

use that as sort of our high end of our range

for distribution.

MS. WILLIAMS: And I do understand

0026

that. I guess, looking, though, at your

numbers, they seem quite low.

MR. ANDES: On what basis?

MS. WILLIAMS: Compared to -- well,

I'm looking at, for a canoer, the range you

give is 5.21 milliliters, per hour, right,

234. But is the highlighted line 50

percentile, what you're relying on?

DR. TOLSON: Yes.

MS. WILLIAMS: So 7.52 milliliters per

hour. And based on your distribution of the

number of hours, I understand you use

statistics and include a lot of things, but a

typical canoer we'd be looking at something

quite a bit less than an event, as U.S. EPA

looks at it for a swimmer, right?

DR. TOLSON: Correct. So we're

getting in a ballpark estimate of 19 mls per

event which is -- compare that to 50 mls from

swimming. I think we're actually being very

conservative. I don't think many would argue

that canoers get less. You would argue.

Okay.

MS. MEYERS-GLEN: If I may have a

0027

quick follow-up. So you're equating the

experience of someone swimming, that

activity, with someone either falling out of

a canoe and being submerged or flipping in a

kayak upside down and then needing to right

themself? That's the same kind of activity

and less of a dose? Is that what -- is that

what you're -- I'm trying to understand --

Please answer.

DR. TOLSON: We didn't specifically

look at capsizing and immersion from any

particular activity. We just tried to define

a continuum, a range, a full range that might

incorporate all the possibilities that would

happen from canoeing. Within that we needed

to debound it somehow. It's not as much as

you would have for drinking water. There's

got to be some sort of reality check on that.

So our high end, our reality check on that

was to say, well, if somebody was swimming

their entire time that they were out on the

river, how much ingestion would you get

there? And we used that to sort of frame our

distribution of ingestion rates.

0028

MS. WILLIAMS: And by frame, do you

mean that we would just make sure it was less

than that? I guess I'm still trying to

understand when you say frame.

DR. TOLSON: That's a reasonable

characterization of it. I mean swimming, do

you ingest more when you swim or when you

canoe?

MS. WILLIAMS: And that's -- the

assumption is you ingest more when you swim

than when you canoe?

DR. TOLSON: Correct. And I'm saying

that we've got a distribution here that

extends beyond what you would have for

swimming.

MS. WILLIAMS: And I -- sorry.

DR. TOLSON: Go ahead.

MS. WILLIAMS: We have a distribution

that goes beyond because why?

DR. TOLSON: If swimming is 50 mls per

event, we have a distribution that can give

values up to five hours at 34 mls per hour,

150 mls. So the highest end of this range

here is three times what EPA recommends for

0029

ingestion rate for swimming.

HEARING OFFICER TIPSORD: Dr. Girard?

CHAIRMAN GIRARD: Dr. Tolson, in the

Geosyntec report which is Exhibit 71. Do you

have your copy there? Could you look at

Page 100 and take a look at the last

paragraph on Page 100 and tell us if that

sort of summarizes some of the answers you've

been giving to these questions?

DR. TOLSON: And I hope it does.

CHAIRMAN GIRARD: I hope so too.

DR. TOLSON: It's written in

mathematicalese here, so excuse that. But

for canoes, a lognormal distribution of a

mean of five and a standard deviation of

five.

HEARING OFFICER TIPSORD: If you're

reading, you need to -- the court reporter.

CHAIRMAN GIRARD: You can summarize

it.

DR. TOLSON: So remember this is a

lognormal distribution, so what that mean of

a log of five gets you a distribution that

looks like the figure in 5 point -- 5-2 of

0030

Exhibit 71.

CHAIRMAN GIRARD: Go to like the third

sentence which starts on Line 4 where you're

talking about ingestion rates for your upper

end.

DR. TOLSON: Got it. It says for the

90th to 100th percentile ingestion rates

range from 14 to 34 mls per hour which

implies that 10 percent of the population may

be exposed to water ingestion rates

approaching those observed in swimming or

accidental gulping.

CHAIRMAN TANNER: Maybe the next one.

DR. TOLSON: The next one is this is

consistent with the observation in Fewtrell

1994 study in which 8 percent of canoeists

report capsizing, an event what that may

result in ingestion rates similar to swimming

or gulping.

HEARING OFFICER TIPSORD: Miss Dexter?

MS. DEXTER: In the ingestion rate

studies that you cited, were any of the

subjects under duress? Was that -- I mean --

I'm not -- no. I'm saying did they study

0031

what happens, how much water is ingested when

somebody is drowning?

DR. TOLSON: If you're drowning on the

CAWS, you've got a lot more issues than

micro --

MS. DEXTER: I'm just saying in an

instance when somebody capsizes a canoe -- or

a kayak and is inexperienced, that's a panic

situation. I'm wondering if there's a

correlation between the swimming studies

where people are playing and when somebody is

actually in a stressful emergency situation.

MR. ANDES: Just a moment.

DR. TOLSON: Actually, I think we may

have the Fewtrell paper here that might

address some of those comments. The Fewtrell

study did not come up with ingestion rates

associated with their 8 percent capsizing,

but it did come up with a conclusion. Let me

read this. Has this been admitted to the

record yet?

HEARING OFFICER TIPSORD: I don't

think so.

MR. ANDES: I believe a partial copy

0032

was introduced by Ms. Alexander.

DR. TOLSON: There are two Fewtrell

papers: One, a 1992 study which has been

admitted to the record, and this one would be

a separate study, a 1994, which is quoted

within the paragraph that I just read out of

the report.

HEARING OFFICER TIPSORD: Okay. Yes,

Exhibit 74 is the other Fewtrell study from

the effects of white water canoeing.

DR. TOLSON: That one is a 1992 study

on white water canoeing. This one is 1994

study on marathon canoeing. And I would like

to point out within the conclusions of the

study, Conclusion 2 says the apparent lack of

identifiable health effects in these studies

suggest that it may be appropriate to use a

relatively polluted water for low contact

recreational activities.

HEARING OFFICER TIPSORD: And do we

have a copy of that we can enter into the

record?

MR. ANDES: We do.

MS. MEYERS-GLEN: Can I ask a

0033

follow-up question to that, because it

dovetails something else I was going to ask

on that report anyway.

THE COURT: Go ahead.

MS. MEYERS-GLEN: Thanks.

HEARING OFFICER TIPSORD: But you need

to speak up and ask one question at a time.

MS. MEYERS-GLEN: Thank you. In

quantifying the amount of water ingested by

canoeists Geosyntec relies on a report, I'm

assuming it's that one, that in studies of

rowing and marathon canoeists, approximately

8 percent of the canoeists at fresh water

sites reported capsizing, and 16 percent of

rowers reported ingesting some water. And

that's actually in your Attachment 3 in the

microbial risk assessment report, Pages 99 to

100.

DR. TOLSON: I agree.

MS. MEYERS-GLEN: My question to you

is do you know the mean level of experience

for the marathon canoeists and rowers

questioned about capsizing in this study?

DR. TOLSON: Clearly no.

0034

MS. MEYERS-GLEN: And what is the

spectrum of experience for the people that

canoe and kayak on -- or jet ski on the CAWS?

DR. TOLSON: I have no knowledge of

that either.

MS. MEYERS-GLEN: Thank you.

MR. ETTINGER: I'm sorry.

HEARING OFFICER TIPSORD: Wait a

minute. Before we get too far away. I am

marking as Exhibit 79 the health effects of

low contact water activities in fresh and

estuarine waters, E-S-T-U-A-R-I-N-E, by L.

Fewtrell, et al. as Exhibit 79, if there is

no objection. Seeing none, it's Exhibit 79.

Mr. Ettinger, go right ahead.

MR. ETTINGER: I'm just trying to

follow-up on Tanner Girard's question

regarding this paragraph on Page 100 of the

report. I understand you had the swimming

figure, and then there's some sort of

mathematical formula. I'm not as well

educated as journalists, so I don't

understand all the math here. But how do

you -- You just shape the bell curve?

0035

What's -- How do you shape that?

DR. TOLSON: It's a lognormal

distribution. I teach a problemistic risk

assessment class. And one of the activities

I do is a couple of days where we work on

this, is I have all the students record the

time that they shower and the time that their

spouse or significant other showers in the

morning and bring it into class next day.

And every year we get the same results; when

you plot all those out, they're not normally

distributed. There are a few people that

have the 20 minute shower, and it's almost

always a lognormal distribution that comes

out of that. Natural processes tend to

produce a lognormal distribution. It's a

multiplicative process associated with a lot

of natural events. If you look at a lot of

indicator data, historically from the

district they tend to follow a lognormal

distribution. So a lognormal distribution is

what we've assigned as sort of the underlying

mathematical expression for how different

people may ingest water. We don't have data

0036

on every one of those to develop those

probabilities, but that fits what we

understand for a lot of natural processes.

MR. ETTINGER: Do you have any data

other than this Fewtrell study and the

swimming data?

DR. TOLSON: Mm-hmm.

MR. ETTINGER: What other data is

there?

DR. TOLSON: Well, if you have the two

points, if you have a point within that

distribution and you have an assumption of

what the distribution is, you can fill the

rest of the distribution in.

MR. ETTINGER: I only see one point.

The one point is the swimming. Where is the

other point?

DR. TOLSON: Zero. We know that

everybody is going to have some ingestion,

incidental ingestion or otherwise. So we

know it doesn't go any lower than that. So

we bounded that -- we've bounded that intake

and then we fit a distribution between those

points.

0037

MR. ETTINGER: So I've been canoeing

for 20 years. I've never capsized a canoe.

Would you say that I had a same chance as

someone who --

DR. TOLSON: I'd say you have a better

canoe record than I do, for one.

MR. ETTINGER: I'm just very cautious.

DR. TOLSON: I would say our estimates

are probably over -- an overestimate for you.

So you are on the left half of the bell

curve, I'm sorry to say, left half of the

distribution.

MR. ETTINGER: So let me get this

right then. You've just got the swimming

point, and then you just put a bell curve on

that with no other data other than this

Fewtrell study that says 8 percent of the

guys capsize.

DR. TOLSON: It's not quite that

simple. I mean you've got -- we can bound

what the numbers are. We know it goes

between zero and something high approaching

swimming. So if you just have that data and

you put a lognormal distribution in, you will

0038

get a picture that looks like the figure

that's in Exhibit 71 of incidental ingestion

rate while for canoeists which is figure 5-2.

MS. WILLIAMS: Did U.S. EPA use a

similar process, or did they use actual data

in correlating their swimming figure?

MR. ANDES: In correlating the

swimming? I'm not sure -- in taking what

action?

MS. WILLIAMS: So, for example, Albert

gave the example of his canoeing. Well, I do

not like to put my head under the water when

I swim. I like to swim with my head out of

the water. I suspect I have less events of

ingesting water than the typical swimmer.

How is the estimate of 50 milliliter per

event translated into the 8 in 10 illnesses

risk of swimming by U.S. EPA? Do you know?

DR. TOLSON: They did not consider

that at all within their 8 per 1,000. But

the way that -- the value that they were

looking at there was a point estimate, their

50. They also add considerable conservatism

with most of their ingestion inputs. And

0039

this is one where I'm sure they did the same.

But it comes from empirical data where

they've got 20 kids, they put them in the

pool, they measure the cyuranic acid, back

calculate how much pool water they ingested,

took the average of that or took the 95th

percentile of that, and that was the number

that they're using for their ingested rate

point estimate of 50 mls per hour.

MS. WILLIAMS: So they did not have to

perform the statistical analysis like you

did?

DR. TOLSON: I don't know how they did

that. My guess is that they would have used

an upper percentile of the range of the data

that they had. So a little bit different of

a statistical one, but a conservative one for

their estimates also.

MR. ETTINGER: Did you do fishing and

boating the same way?

DR. TOLSON: Fishing and boating are

also input distributions that will follow

some sort of lognormal pattern. For fishing

we took the canoeing median of -- and we

0040

essentially halved it. We said for fishing

you would get maybe half of the intake that

you would get for canoeing.

MR. ETTINGER: How do you figure that?

DR. TOLSON: There is like no data out

there to calculate this. So this is a

professional judgment. We think it's a

conservative judgment based on my experience

with fishing.

MS. WILLIAMS: Your personal

experience as a fisherman?

DR. TOLSON: I won't say we're basing

it completely on my personal experience as a

fisherman, but from what I've seen on TV,

that's --

MR. ETTINGER: My personal experience

is I get my hands all over the fish trying to

get the hook out. But I've never capsized a

canoe, so I guess I would have doubled the

other way, right? Oh, well.

DR. TOLSON: Again, there are some

professional judgment evaluations that go

into here. We're using the fishing and the

canoeing and the boating as sort of

0041

representative of groups of high, medium, and

low exposure. So your fishing is more of a

high exposure, I guess, and your canoeing is

a low. I think what we're we've done here,

we've tried to capture in a conservative

fashion the potential for ingestion from

these three exposure events.

MS. WILLIAMS: So in Question 14 I

ask, and I may jump around a bit here. I'm

trying to be chronological, but I don't think

it's working. You testified that select --

quote, selection of input distributions

relied on literature derived sources,

site-specific use information, and

professional judgment. So which of these

sources was used to estimate how long a

canoeist or kayaker will be out in the water?

And so I'm referring to, I guess, now to one

of the tables. Do you have a table?

DR. TOLSON: It might be helpful go to

Figure 5.3. It's a pictorial sort of

representation to it as opposed to the

tabular form of Exhibit 71. That's a

probability density -- you have it? That's a

0042

probability density function for exposure

duration for canoeists. Again, we need to

sort of bound the range of what's possible

out here, somebody is there for probably more

than zero and less than twelve all day,

probably make a better guess than that. If

you're going to go out and go canoeing, we

assume that you're out for at least an hour

and we assume that you're out there for no

more than five hours. That seemed like a

reasonable range.

MS. WILLIAMS: So that answer to the

question would be -- would it be it's not

literature derived.

DR. TOLSON: No. I'm getting to some

more specific data, I think, that will inform

the --

MR. ANDES: I do have copies of that

figure if anyone needs that. Do you have

that?

HEARING OFFICER TIPSORD: Actually,

we --

DR. TOLSON: For this particular input

there actually is survey data. This is much

0043

easier to conduct. So there is survey data.

And I believe EPA exposure factors handbook,

the activity factors handbook which is one of

the chapters in this huge volume of survey

information that EPA has collected, has data

on use statistics for parks and recreations

around lakes, streams, and rivers. And the

distribution that you see here which is a

triangular distribution fits fairly nicely

with the 10th and 90th percentiles of the

recreational use for rivers and lakes. So

there we have the exposure factors handbook

data to sort of inform our decision. The

problem with that data is we don't know if

they were actually out there canoeing or not.

So they were just used, they were recreating

in parks that had streams and lakes. So it

may have included the time that they were in

the parking lot before they got on the water.

There was a lot of other uncertainties

associated with that.

MS. WILLIAMS: So you're saying only

10 percent of the people would have been

recreating for more than five hours?

0044

DR. TOLSON: Correct. That's their

total recreation there based on that survey.

There were -- I think there was some in the

survey there that had 24 hours for their

recreation time. So they may have included

homeless and such that were in the parks.

MS. WILLIAMS: Campers are not

homeless.

DR. TOLSON: I'm sorry. It may have

included campers in there, but probably not

people that are out on canoes. So I'm not

sure how -- It's not directly relevant to

fitting this distribution or we would have

used that direct information. So what we've

got here fits within the 90 -- 10th to 90th

percentile. Because of the uncertainties

associated with time that was not canoeing

but also in the park, this probably

overestimates the time that one would be in

canoes based on that data. It's also

interesting to note that the mean that we've

got, 2.67, which is the mean of that

triangular distribution, is also greater than

the mean of the data from that survey

0045

information which is like two and a half

hours or something like that.

MS. WILLIAMS: How did you get your

mean?

DR. TOLSON: How did we generate our

mean?

MS. WILLIAMS: Yes.

DR. TOLSON: It's a triangular

distribution. You can analytically calculate

what the mean is or you can probabilistically

do it by just doing simulations and averaging

up what the simulations are and dividing by

the number of simulations.

MS. MEYERS-GLEN: Can I ask a

follow-up?

MS. WILLIAMS: Yes.

MS. MEYERS-GLEN: Question No. 12 for

you, this is right in line with that.

HEARING OFFICER TIPSORD: Stacy, we

cannot hear you at all.

MS. MEYERS-GLEN: On Page 101 of the

microbial risk assessment report, that's your

Attachment 3 to Dr. Tolson's testimony, I

would ask Dr. Tolson my question 12 for him,

0046

since it seems kind of relevant: According

to the report, that would be the microbial

risk assessment, Geosyntec set exposure

duration based on time for the Flat Water

Classic, a canoe and kayak race in the

Chicago River. And the report states that

according to friends of the Chicago River,

race times in 2005 range from approximately

1 to 3.5 hours with majority times between

1.5 and 2.5 hours.

DR. TOLSON: Correct. I'm sorry. I

should have also included that in your

answer. We used other sources besides the

EPA.

MS. MEYERS-GLEN: Well, the report

concluded, though, that based on this

information and professional judgment, again,

triangular distribution was assigned to this

input with a minimum time the canoeists must

be in the water one hour, and the likeliest

time in water for two hours. And my

questions to you are, first one: If

Geosyntec was aware that the average time of

a race, and this is where people are trying

0047

to paddle as quickly as possible to reach the

finish line, is between 1.5 and 2.5 hours,

why did the team select an even faster range

between 1 and 2 hours as the time a person

would normally spend in a canoe and kayak on

the CAWS?

DR. TOLSON: I think you might have a

little bit of misinterpretation of the ranges

there. If you go back to Figure 5-3 of the

report, and if you look, the majority of the

Flat Water Classic canoe racers were between,

what did we say, one and a half and two and a

half hours.

MS. MEYERS-GLEN: Right.

DR. TOLSON: One and a half and two

and a half hours. And you can see we

actually estimated that exposure to the river

is much longer, out to five hours. So if we

were using that as a basis, then we've

certainly overestimated, probably

overestimated by a factor of two.

MS. MEYERS-GLEN: I'm a little

confused, though. Because the next statement

says here, "The training and distribution

0048

that signed this input was a minimum time the

canoeist would be in the water of one hour."

And I'm confused as to why that one hour was

chosen when during a race the average time --

the quick time for that average was 1.5, and

the fastest time that anyone could even

paddle would have been an hour, when you're

talking about a regular occurrence on the

CAWS.

HEARING OFFICER TIPSORD: You keep

asking compound questions. You need to stop

after a question.

DR. TOLSON: Can we back up. And the

first question then again was?

MS. MEYERS-GLEN: Yes. The minimum

time a canoeist would be in the water chosen

here on Page 101 of your report is an hour,

right?

DR. TOLSON: Yes. That is correct.

And it's obviously the shorter the exposure,

the lower the ingestion, potential ingestion,

so yes.

MS. MEYERS-GLEN: Right. And you

chose that from the Flat Water Classic; is

0049

that correct?

DR. TOLSON: We did not chose our

input distribution on ingestion based solely

on the Flat Water Classic. I think we

informed our choice based on information from

EPA surveys on recreational use around lakes

and parks, and we also looked at the Flat

Water Classic which is clearly people

canoeing on the waterway, something we should

look at. When we look at it in context of

the Flat Water Classic, we find that our

distribution that we're using here certainly

incorporates those people and actually

overestimates through the entire range the

length of time people are there compared to

the length of time people were on the Flat

Water Classic.

MS. MEYERS-GLEN: Well, did you use

any other information about recreation on the

CAWS other than the race, the Flat Water

Classic, to determine the average amount of

time that recreators are normally out on that

water -- on those waters?

DR. TOLSON: Yes, we did. I'm trying

0050

to recall the specifics on this. But we

actually contacted some boat rental

facilities on renting boats, and I believe we

got information that they had half-day boat

rentals and one-hour boat rentals, and that

was just sort of ancillary information that

we put into our potential for recreating.

Somebody was going to rent a boat for an

hour, they're going to be out there for

probably an hour.

MR. ANDES: Can I follow up?

MS. MEYERS-GLEN: Sure.

MR. ANDES: First, Dr. Tolson, let me

ask: By using one hour's lower bound, if you

had included smaller time periods of

exposure, would those have shown less risk?

DR. TOLSON: That is correct. By

truncating it at the one hour, we've

increased our -- the exposure time and

increased the ingestion rate and potentially

overestimated risk for those recreators who

were out there for less than one hour.

MR. ANDES: And then in terms of the

first question here which says that the team

0051

selected a range of between one and two

hours, is that right, or -- in fact, can you

explain what the two hours -- when you say

the likeliest time in the water is two hours,

can you explain what that represents and then

explain to us what the range really is that

you're using?

DR. TOLSON: Sure. The likeliest time

is just the mid point on that, the one is the

beginning point. But we don't talk

specifically there in that sentence about the

high end, which is five hours. So I think

the misinterpretation is that you're taking

the minimum and the mean, median, or the most

likely number, and comparing that to the

range of the median for the race.

MS. MEYERS-GLEN: You want your

minimum, though, to reflect what truly is a

minimum out in the water, though, correct?

You don't want it to be --

DR. TOLSON: The minimum amount in the

water may be five minutes. We did not

reflect that. So in that respect we probably

overestimated the risk for those people.

0052

MS. MEYERS-GLEN: Based on the

information, though, that you've collected,

based on the Flat Water Classic, the EPA

study, as well as rental locations, that's --

what was the minimum that you found from

those three sources out in the water?

DR. TOLSON: We don't have any

specific -- We do not have any specific data

on the rental times exactly how long people

were on canoes. For the Flat Water Classic,

I do not recall who the winner, what the

winner got as far as time. You may know. Is

it less than one hour? And, if so, then his

risk would be even that one person would be

overestimated with the evaluation as we've

done it here.

HEARING OFFICER TIPSORD: Dr. Tolson,

did you testify also that there are rental

places that rent boats for merely an hour?

DR. TOLSON: I believe there are, yes.

At least in 2005 when we --

HEARING OFFICER TIPSORD: Thank you.

MS. MEYERS-GLEN: Well, did you

consider, and I guess I don't know if you

0053

would, because I didn't realize that you had

this other information, but did you consider

other tour events such as Windy City Kayak

Symposium, which offers numerous kayak

trips --

HEARING OFFICER TIPSORD: Slow down,

slow down, slow down.

MS. MEYERS-GLEN: -- that take from

three to six hours. And actually the range

from Friends of the Chicago River, who was

instrumental in the Flat Water Classic where

you got your other information, and all of

their kayak trips last at least from three

hours and mostly between three and six hours.

MR. ANDES: And I assume at some point

that would be offered as evidence, because we

don't have that to date.

DR. TOLSON: I do not have any survey

data from them, any published reports or

anything from them.

MS. MEYERS-GLEN: So you're not aware

of any of that and that wasn't taken into

account?

DR. TOLSON: That's correct. Long

0054

time periods were taken into account within

our distribution up to five hours. There may

have been people that can canoe out there all

day. I can't hold my bladder that long.

MS. MEYERS-GLEN: Those sources were

not taken into account, correct?

DR. TOLSON: I have not looked at any

data, any survey data from alternative sort

of races or events that have been on the

waterway. However, I believe our

distribution that we've included for our

ingestion rate takes into account a wide

range of potential exposures on the waterway

that, in my opinion, are a conservative

estimate of time that people spend on the

waterway in canoes.

MS. MEYERS-GLEN: Thank you.

MS. WILLIAMS: Did you, by any chance,

review the testimony from the June 16 hearing

yet in this matter?

DR. TOLSON: I'm sorry. I did not.

MS. WILLIAMS: Yes or no is fine.

That's fine.

CHAIRMAN GIRARD: Could I ask a quick

0055

follow-up?

MS. WILLIAMS: Yes.

CHAIRMAN GIRARD: Dr. Tolson, looking

at your Figure 5-3, you say you've -- you

have a mean duration of two -- well, 2.67 or

two hours and 40 minutes. Just eyeballing

your graph there, what do you think the

median would be in terms of half the people

spend less time and half above? Would it --

would the median be somewhere around three

hours?

DR. TOLSON: The median would be lower

than that.

CHAIRMAN GIRARD: Okay. So it would

be -- but somewhere between two and

two-thirds?

DR. TOLSON: Yes.

CHAIRMAN GIRARD: So still you're

saying that even though your range is one to

five hours, you've got a lot of individuals

there in the mid range in terms of two to

three hours' time in water?

DR. TOLSON: That is correct. There

are more people that are in the two to three

0056

hour than there are between the three and the

four and the four and the five. And as in

most of these skewed distributions, the

tails -- less and less frequency in the upper

tails.

CHAIRMAN GIRARD: Thank you.

HEARING OFFICER TIPSORD:

Miss Williams, I think we're back to you.

MS. WILLIAMS: I guess I'm looking at

question ten now. On Page 3 of your

testimony you state that recreational survey

studies were used to provide insight on the

types and frequency of recreational exposure

expected in the waterway. Now, this is

referring to something different than what

we've been talking about previously, correct?

What surveys are you talking about here?

DR. TOLSON: We relied solely on the

UAA as the survey for that.

MS. WILLIAMS: And did those surveys

consider the length of time or how -- or the

frequency of recreation or anything?

DR. TOLSON: To my knowledge the UAA

did not contain that information.

0057

MS. WILLIAMS: And do you know who

conducted those surveys that were in the UAA?

MR. ANDES: It's in an Agency

document. You're asking him --

MS. WILLIAMS: I'm asking him if he

knows who conducted those surveys.

DR. TOLSON: There were notes on the

observation pages, but I don't remember,

recall the names of those that were involved

with that.

MS. WILLIAMS: Okay.

HEARING OFFICER TIPSORD: And, for the

record, the UAA we're talking about is the

one that is Exhibit B to the Agency's

proposal.

MS. WILLIAMS: I'm sorry. Attachment

HEARING OFFICER TIPSORD: Attachment

B. Sorry. Only because there are two of

them in the record, I thought we should

specify.

MS. WILLIAMS: Yes. And you

haven't -- you weren't able to look at any of

the work that's being done by Dr. Dorovich

0058

(ph.) regarding recreation in the CAWS. That

wasn't -- there's nothing available from his

work about frequency or types of recreation,

correct?

DR. TOLSON: This study was concluded,

I think, before we had sufficient data to

even consider that.

HEARING OFFICER TIPSORD: Have you had

a chance to review his findings?

DR. TOLSON: We were not privy to -- I

haven't seen it, so.

MS. WILLIAMS: So when you were

testifying yesterday, Ms. Alexander, I think,

understood better than I do, about -- I think

one of the witnesses referred to the fact

that's like gambling; going out more often to

recreate your risk, it's not additive, but

it's more like gambling. Can you explain

what that means?

DR. TOLSON: You leave with less

money. Yeah. It's important to understand

that the cumulative risk or the risk from

repeated exposures, there's a lot of other

caveats that had to be considered in here.

0059

One is there's immunity, and immunity may

influence the probability of getting infected

on repeated exposures. And we didn't take

that into account. That's an uncertainty

that I think we've discussed to some extent

within here. The other is how one would take

five exposure events that may have a

1 percent chance of risk of illness and

figuring out at the end of that one what was

the probability that I would have gotten sick

somewhere along that time. And there it's

not just 5 percent which would be 5 times 1

percent. If you can think about it in terms

of -- let's talk about in gambling. Say that

you had a deck of cards and you wanted to get

hearts. That was your outcome that you

were -- you were wanting to get a red card.

That was your outcome that you were

interested in. If you were to be dealt one

card out, there's a 50 percent chance it

would be a red card and 50 percent chance it

would be a black card. So if you were to be

dealt two cards face down, if it's 50 percent

chance on the first one and a 50 percent

0060

chance on the second one. Then you would

conclude that I'm going to get a red card out

of those two, and that's not the case. So

it's not just strictly additive. Does that

address it?

MS. WILLIAMS: It's not strictly

additive.

DR. TOLSON: It's not additive at all.

It's independent events.

HEARING OFFICER TIPSORD: Can I just

try to --

MS. WILLIAMS: Do you have a good way

of asking it?

HEARING OFFICER TIPSORD: Let me try

this. So, in other words, if I go out every

single day and swallow a milliliter of water

from the CAWS, my chances of getting sick are

the same every single day, but they don't

increase every day?

DR. TOLSON: Yeah. It's a little bit

more complicated than even that, because

actually your chances of getting sick are

actually less after each day.

HEARING OFFICER TIPSORD: Because you

0061

begin to build an immunity?

DR. TOLSON: That is correct.

MS. WILLIAMS: But still somehow if I

just go out and take a milliliter one day, my

risk must be lower than Marie's over the

whole summer, right?

DR. TOLSON: I'll agree with that,

yes.

MS. WILLIAMS: But your report doesn't

account for --

HEARING OFFICER TIPSORD: But that's

because if I'm going out every day, my

exposure is more often; not because the

increased quantity of water.

DR. TOLSON: Absolutely.

MS. WILLIAMS: But when you are giving

a risk level --

DR. GERBA: Basically that's what the

EPA does in setting -- based on their

epidemiological data. Your risk of getting

ill is an independent event. When they set

those enterococci or E. Coli standards based

upon the number of days they get ill, that's

every time they go out. That's the event.

0062

They don't consider it's a cumulative process

because it's not additive. That's based on

one time swimming event each time.

HEARING OFFICER TIPSORD: We have

another follow-up back there.

MS. HEDMAN: Susan Hedman from the

office of the Attorney General on Behalf of

the People of the State of Illinois. I'd

like to follow up with Dr. Gerba on this

exchange about risk. Isn't it true that from

the perspective of the recreational user of

the CAWS this is much like a game of Russian

roulette only with pathogens instead of

bullets?

DR. GERBA: Right. It gives it -- The

events are independent of each other every

time you play Russian roulette, right?

MS. HEDMAN: And you've over the years

I think frequently invoked that analogy; is

that right?

DR. GERBA: That's right.

MS. HEDMAN: Is it true that you said

that every time you go to the bathroom you're

playing Russian roulette?

0063

DR. GERBA: It depends whose bathroom

you use.

MR. ANDES: Can we cite where he said

that?

DR. GERBA: I'm sure I have.

MS. HEDMAN: I mean if I can enter the

article into evidence as an exhibit.

HEARING OFFICER TIPSORD: Absolutely.

MS. HEDMAN: It's a 1997 article from

the Arizona Daily Wildcat, and I believe it

is about a study that Dr. Gerba did relating

to use of bacterial infections from use of --

and pathogenic infections from use of public

bathrooms.

DR. GERBA: That's sort of the analogy

we're using here, actually.

HEARING OFFICER TIPSORD: I'm going to

mark this as Exhibit 80 if there's no

objection. Seeing none, it's Exhibit 80.

MS. HEDMAN: And I also would like for

you to tell me if you recognize the following

statement, this is from a transcript of an

interview you did on the Today Show in 2005,

and you were talking about --

0064

MR. ANDES: Can I ask why these

couldn't have been provided earlier so we

could see them before he has to answer

questions?

MS. WILLIAMS: Are these articles

cited in his --

MR. ANDES: No.

MS. HEDMAN: This morning when he was

testifying he used the phrase the right spot

at the wrong time, and I recalled him using

that same phrase in a discussion of risk

assessment in a Today Show interview I read

about him. And I would just like to -- we're

trying to clarify what is this risk

assessment model. And we talked a lot about

Monte Carlo models. We talk about all kinds

of simulations. We've talked about all kinds

of sophisticated risk assessment models. And

we're trying to pin down this question of

what is the risk to the recreational user.

And --

MR. ANDES: And I don't think that

addresses my question of why these materials

couldn't have been provided earlier.

0065

HEARING OFFICER TIPSORD: Because she

found them as a result of his testimony this

morning as a follow-up.

MR. ANDES: You only found those

today?

MS. HEDMAN: Yes, I did. In fact, you

can see that I printed them out today. I

have -- when I saw his testimony, as with all

the witnesses, I did a fair amount of reading

of other statements that they made.

MR. ANDES: So his prefiled testimony?

MS. HEDMAN: Yes.

MR. ANDES: That was certainly

available before yesterday.

MS. HEDMAN: That's true. I didn't

know that it would come up.

HEARING OFFICER TIPSORD: We can go

ahead. He can certainly answer them to the

best of his ability without being

reacquainted with them.

MR. ANDES: Fine. Okay.

MS. HEDMAN: Well, I just have one

more question, and that is whether you recall

saying in that Today Show interview, and I

0066

will enter this into evidence as well,

talking about exposure to pathogens in the

workplace.

DR. GERBA: Right.

MS. HEDMAN: Quote, it's sort of like

germ roulette. You know, you touch the right

spot at the wrong time and you bring your

fingers to your nose, mouth, or your eyes,

you can pick up colds that way. Eighty

percent of the infections you get you're

going to pick up from your environment.

DR. GERBA: Right.

MS. HEDMAN: I thank you. That's it.

HEARING OFFICER TIPSORD: Let's enter

that as an exhibit as well.

DR. GERBA: It's a lot more dangerous

to go to your office than to go canoeing on

the CAWS.

MS. HEDMAN: But from the perspective

of the recreational user of the CAWS?

DR. GERBA: Right. It's a matter of

your exposure and how much you're exposed to

the concentration. So that's a good -- in

fact, we use that -- I use that as a classic

0067

example in teaching about risk and risk

assessment about how it's all -- how it's a

gamble and how you calculate what your odds

are. The whole thing with any type of

exposure is always to keep your odds in your

favor and not in the organism's favor.

HEARING OFFICER TIPSORD: If there's

no objection, I will mark that as Exhibit 81.

Seeing none, it's marked as Exhibit 81. I

would, however, note that both Exhibit 80 and

81 contain markings in both a yellow

highlight and also asterisks in black pen

that were on the documents when I received

them.

MS. WILLIAMS: Okay. So, Dr. Tolson,

the risk in the three segments you studied

was significantly lower in the -- I believe

the Calumet. That was the lowest.

MR. ANDES: Which particular risk are

you referring to?

MS. WILLIAMS: I guess we can look at

Question 17. You conclude that the Calumet

Waterway was the lowest illness rate compared

to North Side and Stickney?

0068

DR. TOLSON: Yes. I'm with you.

MS. WILLIAMS: And the question is

why, but I guess to refine it more is that

because there are fewer recreators primarily

or because the pathogen levels are lower.

DR. TOLSON: The number of recreators

is not important here. It's what kind of

recreational activity they were doing. If

they were doing recreational activities with

somebody who is in the category of high

exposure group, then they would ingest more

water; couple that with the fact that the

Calumet tended to have lower levels of

pathogens, including viruses which are mostly

responsible for the secondary illness, that's

why you get both low incidents of primary --

when I say primary, I mean the actual

recreators getting ill from the Calumet, and

you get lower incidents of secondary illness

from Calumet exposure.

MS. WILLIAMS: Did one of those

factors have more influence over the other,

the type of recreation versus the pathogen

level?

0069

DR. TOLSON: Give me a second. I

might be able to give you an exact answer.

Yes. Actually, we did a quantitative

evaluation of that. The receptor type input

was responsible for 38 percent of the

variance in the distribution of the

exposures.

MR. ANDES: What table is that?

DR. TOLSON: This is Table 5-16 in

Exhibit 71. So here it kind of ranks the

sensitivity of the model to the various

inputs. You can see for Calumet we have .38

for receptor type, .05 for weather type, .02

for fishing ingestion rate, how that

distribution affects it. And you had asked

about what was it, duration.

MS. WILLIAMS: Pathogen levels. I

don't think that's on here.

DR. TOLSON: Well, pathogen levels are

not included within this sort of sensitivity

analysis because they were handled in a

bootstrapping scenario. So the pathogen

levels are what they are.

MS. WILLIAMS: Do you know why they're

0070

lower in Calumet?

DR. TOLSON: Why pathogen levels are

lower?

MS. WILLIAMS: Yes.

DR. TOLSON: We base that on our

analytical data which is probably the most

robust pathogen analytical data --

MR. ANDES: So your answer is --

MS. WILLIAMS: Did you say the most

robust what?

DR. TOLSON: Pathogen recreation --

recreational water pathogen microbiological

survey that, you know, I can think of based

on that data.

MS. WILLIAMS: Robust in terms of the

number of samples or the variety of pathogen

sampled for?

DR. TOLSON: We have a number of

pathogens, we have a number of sampling

locations, we have wet and dry weather

events. All of those really signify that

this is a study that has taken into account a

number of the different factors that have

been missed in other surveys of pathogens.

0071

MS. WILLIAMS: So other surveys have

fewer numbers of samples?

DR. TOLSON: There are some literature

citations out there of pathogens and

waterways that were single events. I think

if Fewtrell's study was pathogens on a single

day, so, yes.

MS. WILLIAMS: Okay. But going

back -- so Calumet had by far the lowest

percentage of canoers, right, in table 5-11

of the three samples?

DR. TOLSON: That is correct.

MS. WILLIAMS: So presumably if there

were more canoers in Calumet, their risk

would have been higher, correct?

DR. TOLSON: That is correct. In

fact, if you go to Table 5-12 and we were to

put everybody in a canoe on the Calumet, the

risk there is .52. So even including

everybody in the highest exposure group, you

can see that the risks are still fairly low

compared to either North Side or Stickney

which had higher pathogen levels. Mind you,

they're all much lower than the 8 per 1,000

0072

that we have been talking about as kind of

our benchmark.

MS. WILLIAMS: So you're saying the

point -- wait. I didn't understand what you

meant by if we put everyone in a canoe.

DR. TOLSON: On Table 5-2 we've

stratified the risk. We've assumed that

every recreational event out of 1,000 there

was a canoeing event in the Calumet. The

risks for that would be .52 illnesses per

1,000 recreational users.

MS. WILLIAMS: So this table reflects

the difference in pathogen levels across.

Would this table be --

DR. TOLSON: Yes, it does.

MS. WILLIAMS: Okay. Thank you.

MR. ETTINGER: Just to be clear, you

have no idea why the pathogen levels varied

from one site to another?

DR. TOLSON: I do not.

DR. GERBA: Why it varies from one

sampling point to the other?

MR. ETTINGER: Yes. Do you have any

idea?

0073

DR. GERBA: It would be speculation.

It's based on flow rates, how much water --

what the per capita water consumption is in

the various wastewater plants. Some plants

may have more industry that uses more water

than another, so that would affect the final

dilution in the pathogens that might be

present, efficiency of the plant. That's a

good one. Those are among a lot of other

factors.

MR. ETTINGER: Efficiency of what

plant?

DR. GERBA: How well the sewage

treatment processes are being operated by the

plant.

MR. ETTINGER: Do we think the

pathogens are coming from sewage treatment

plants?

DR. GERBA: Some of them could be,

yes. That's what the outfall data suggests.

MR. ANDES: If I can follow up on

that. And there is some reduction of

pathogen levels --

DR. GERBA: Just in sewage treatment

0074

itself you get significant reductions of

pathogens than most of them in it. An

example, helmet worms (sic.) would be a

classic example. You'd probably remove

almost all of them in the sewage --

MR. ANDES: Can you repeat that and

speak up a little bit.

DR. GERBA: Helmet worms would be a

classic example of that. You probably remove

almost 100 percent of them in the sewage

treatment process. It varies with the

individual pathogens. Some you remove more

and some you remove less.

MR. ETTINGER: That's with secondary

treatment you would remove 100 percent of

that particular pathogen?

DR. GERBA: That particular one, yeah.

But it varies with other pathogens. Some you

might remove only 90 percent.

MR. ANDES: You're not talking about

with disinfection specifically? You're

talking about --

DR. GERBA: No. This is without

disinfection.

0075

MR. ETTINGER: I understood that.

MR. ANDES: I want to make sure

everyone did.

MR. ETTINGER: Okay. And when we have

these high pathogen levels or higher pathogen

levels during wet weather events, that could

be or I guess -- well I'll ask you. Do you

think that is because we're then seeing raw

sewage going in from the CSOs?

DR. GERBA: That's what I presume

since there are CSOs present that discharge

into the waterway during the wet water

events, yeah.

MR. ANDES: Are there other sources as

well?

DR. GERBA: There could be other

sources, too. Animals could contribute,

birds can contribute, large numbers of

pathogens, for example, like kafla bacter

(ph.).

HEARING OFFICER TIPSORD: Mr. Harley,

follow-up?

MR. HARLEY: Keith Harley. I

apologize I had to be in and out today, and I

0076

know that Mr. Andes will interrupt me if

you've already answered this question. I was

trying to understand some differences in

testimony between General Superintendent

Lanyon and what we heard yesterday on this

very point. General Superintendent Lanyon

indicated that he believed that there were

pathogen levels 10 to 200,000 colony forming

units at the point of discharge. Yesterday

you testified that that did not correspond

with the levels that you saw and you used, as

an example, the North Side plant. Am I

correct so far?

MS. PETROPOULOU: I think he was

referring to fecal coliform concentrations.

MR. HARLEY: My point is still this:

You testified that there were 42,000 and

56,000 colony forming units during dry

weather at the North Side plant; is that

correct?

MS. PETROPOULOU: I can verify that

for you. I think I was reading from the

report, right?

MR. HARLEY: You were reading from the

0077

report.

MS. PETROPOULOU: And I think I was

reading fecal coliform concentrations, not

pathogens.

MR. HARLEY: Oh, okay. My question is

this: Were your subsequent risk assessments

based on a particular level of pathogens

being in effluent at the point of outflow?

MS. PETROPOULOU: Pathogens you said?

MR. HARLEY: Yes.

DR. TOLSON: I don't -- we discussed

in some -- we discussed quite a bit about how

we developed pathogen concentrations in the

waterway. The concentrations that

Mr. Lanyon -- Dr. Lanyon discussed were not

pathogenic fecal coliform. If you want to

characterize the range that he gave compared

to the range that we found in our study. Is

that the question?

MR. HARLEY: It's part of the

question, yes.

DR. TOLSON: Well, if I were to look

at people's heights, that would be my thing

that I'm looking at, and if I were to take a

0078

sample by looking at this room and developing

a range for U.S. citizen heights, I would get

some numbers that would balance between

something. This is a representation of

potentially the U.S. population. But if I

were to go out and look at everybody in the

Thompson Center here, I'd probably find

people that were on the extreme. So what you

see is you see records from the district that

are 20 years, I don't know how long they've

been measuring there, but probably quite a

long time --

MR. ANDES: And I think -- if I can

stop you there. We could read back

Mr. Lanyon's statement, but I think it was a

general statement in terms of what's in

effluent. It wasn't specific to a facility.

MR. HARLEY: I guess my question then

is this: In the absence of a numeric permit

limit -- in the absence of a numeric permit

limit on either pathogens or indicators, what

is to prevent any plant from discharging an

amount of pathogens or indicators far in

excess of what's contained as your assumption

0079

and your risk assessment?

MR. ANDES: That's a legal question.

I'll object. He's asking what's to

prevent -- in the absence of a numeric limit.

They're scientists. They're not lawyers.

MR. HARLEY: Would your risk

assessment change if the level of pathogens

from an unregulated search --

MR. ANDES: I'll object to the

characterization. They have a permit.

They're not unregulated.

HEARING OFFICER TIPSORD: Why don't

you try it this way -- or let me, Mr. Harley,

if I might.

MR. HARLEY: I think you know exactly

where I'm going.

HEARING OFFICER TIPSORD: Would your

assumptions change if there was a discharge

of pathogens in excess of what you've seen in

the sampling? Is that close enough?

MR. HARLEY: That's -- it's a

hypothetical.

HEARING OFFICER TIPSORD: What if the

pathogens -- what if somebody discharged

0080

double the amount of pathogens you saw in

your sample?

DR. TOLSON: Yes. Clearly that's the

case. If you change the numbers, you change

the risks. I mean our risks are based on our

measured pathogen concentrations in the

waterway which, as I stated before, is a very

robust sample. It has a number of samples

along the waterway, it includes dry and wet

weather. So, yes, if our representation of

the waterway is different than a different

representation, the outcome risk will change.

MR. HARLEY: To your knowledge, in the

absence of a numeric permit limit, could such

an elevated level of pathogens discharge

occur at one of these sewage treatment

plants?

MR. ANDES: Objection again. They're

not qualified to opine on what happens in the

absence of numeric permit limit.

HEARING OFFICER TIPSORD: I'll sustain

that.

MR. HARLEY: Another question I have

is you mentioned disparity between very high

0081

levels and low levels. Is it possible that

you could have an extreme event that is

outside the range of what you observed in

your risk assessment in terms of pathogen or

indicator loading from a sewage treatment

plant?

DR. TOLSON: We tried to capture that,

to some degree, qualitatively by actually

sampling the outfalls. While it's possible

that we could have a drinking water epidemic

within the city that may cause effluent

levels to change for some of the pathogens,

there are lots of things that are possible.

So yes.

MR. HARLEY: Thank you.

HEARING OFFICER TIPSORD: Go ahead.

MS. WILLIAMS: Well, let me ask, you

have said this a couple times about the

robust sampling, so let me go to Question 22.

On Page 7 you testified that the weather and

waterway sampling relied on a representative

of the entire recreational year. And my

question was how was the representativeness

of the data determined? And I guess what I'm

0082

asking at this point, Mr. Tolson, is did you

rely on Miss Petropoulou for the

representedness of data? Did you make your

own conclusion about this data?

MR. ANDES: Can you address weather

and then waterway separately?

MS. WILLIAMS: That's fine.

DR. TOLSON: Tell me which question

you're on.

MR. ANDES: Twenty-two.

DR. TOLSON: So the weather as we

discussed yesterday is representative because

we actually used meteorological data from

that year. So are we good with that?

MS. WILLIAMS: Yes. Let's talk about

the pathogen sampling.

DR. TOLSON: The pathogen sampling, we

constructed a sampling program that would

capture both dry and wet weather events.

MS. WILLIAMS: And you were involved

in that as well?

DR. TOLSON: I was involved in the

discussions leading to that sampling event.

HEARING OFFICER TIPSORD: I'm sorry.

0083

That was the protocol we discussed with

Dr. --

MS. WILLIAMS: So you agree then that

just two years' worth of data is sufficient

to be representative?

MR. ANDES: Representative of what?

All recorded time?

MS. WILLIAMS: Of all years.

DR. TOLSON: I'm going to punt to

Dr. Gerba, because he probably has more

experience in looking at other waterway

sampling data.

DR. GERBA: Without the data, I can't

say that. I mean I don't know what the

pathogens were ten years ago or are going to

be ten -- in the future probably.

MR. ANDES: Let me follow up on that.

You looked at wet weather events and you

looked at dry weather events. And reasonably

is there anything else you should have looked

at?

DR. GERBA: Those would have the --

wet weather events would have the biggest

impact on water quality within the waterway.

0084

MS. WILLIAMS: I think the question is

whether the wet weather data and the dry

weather data you looked at were

representative of all wet weather and dry

weather data?

DR. TOLSON: From a purely statistical

standpoint, it's a representative sample from

the 2006 waterway concentration. So, yes, it

is representative samples.

HEARING OFFICER TIPSORD: If I may, I

think -- So when you state in your testimony,

Dr. Tolson, that it's representative of the

entire recreational year, you mean for the

years of the study?

DR. TOLSON: Correct. For the years

in the study and the weather types within the

study; the dry weather days, the wet weather

days.

HEARING OFFICER TIPSORD: But not

necessarily for --

DR. TOLSON: I can't for the things

for which we have no data.

HEARING OFFICER TIPSORD: Not for the

entire 2000s. Just for those two years.

0085

MS. WILLIAMS: We've -- I think we've

already established 2005 wasn't a typical

year, correct?

DR. TOLSON: It was a dry year,

correct.

MS. WILLIAMS: Would you say 2006 was

a typical year?

DR. TOLSON: I don't have the data to

characterize 2006. However, whether it was

atypical or not, I don't think it would have

made a big difference in our assessment

because we selectively went for wet weather

days whether it was a wet weather day that

happened as a one-time event in a year where

it didn't rain, or whether it had rained the

week before I don't think would make much of

a difference in our assessment.

MS. WILLIAMS: Did you, in making this

statement in your testimony that this

sampling is representative, did you consider

the actual methodology that was used to

collect the samples? Or I mean did you --

are you --

MR. ANDES: You mean the sampling

0086

methodology?

MS. WILLIAMS: Yes. Are you speaking

to the sampling methodology as well?

DR. TOLSON: I'm not speaking to that.

The data is what the data is.

MR. ANDES: I may be able to clarify

it with a follow-up. To the extent that your

waterway sampling was focussed near the

sewage treatment plant, it would actually be

conservative in terms of the levels that you

would have seen; is that right?

DR. TOLSON: That is correct.

MS. WILLIAMS: But if it was closer,

it would have been higher, right? I mean I

don't understand why that --

MR. ANDES: They were -- As I

understand it, you focussed particularly on

areas close to the plants?

DR. TOLSON: Under dry water

conditions they were within 10 to 15 waterway

widths from the outfalls the Stickney, North

Side, and Calumet.

MS. WILLIAMS: And when you stick the

dry weather samples you sampled in three

0087

locations in the stream and put them together

as a composite, correct?

MS. PETROPOULOU: No. We sampled

actually at one upstream location at two

depths, one meter and the surface. And then

one downstream location.

MS. WILLIAMS: So at your upstream and

downstream locations, you did not take

samples both at the each bank and in the

center?

MS. PETROPOULOU: What we did, we

actually composed it across the width of the

channel. With one on the left side, we

collected one-third of the volume, then both

moved to the center of the channel, they

collected a third of the volume there, and

then on the right side of the channel.

MS. WILLIAMS: Did you do the same

thing with the wet weather samples?

MS. PETROPOULOU: No. We didn't do

that during the wet weather sampling because

Dr. Gerba surveyed the waterway. And based

on his experience with sampling, he didn't

think that the channels were wide enough to

0088

provide information.

MR. ANDES: You can have him

perhaps --

MS. WILLIAMS: Can you explain,

Dr. Gerba, why you recommended they sample

differently during wet weather than they did

during dry weather?

DR. GERBA: You mean the number of

samples? I'm not sure differently, what --

MS. WILLIAMS: The methodology --

MS. PETROPOULOU: The sampling that we

did during the dry weather that included the

sides of the channel. And then the center,

during wet weather, we did it in the center

of the channel.

DR. GERBA: Because there wasn't

really -- I think maybe you should answer

that. There wasn't any difference in data

statistically.

MS. PETROPOULOU: Well, we looked at

the difference -- yeah. We looked at the

difference at one meter and the surface.

During wet weather we went to the center of

the channel.

0089

MS. WILLIAMS: Because?

MS. PETROPOULOU: Because the width of

the channel, it wasn't a very wide -- the

width of the channel, based on the

discussions with Dr. Gerba, was not wide

enough to -- worth the extra effort to

composite from the sides and the center. So

what we captured during wet weather, it was

what we measured in the center of the

channel.

MR. ANDES: Would that logically be

the maximum for a higher --

DR. GERBA: We have a high flow in

there, yeah. It's going to be flowing in

there rapidly.

MR. ANDES: In the middle in

particular?

DR. GERBA: That's right.

MS. WILLIAMS: Isn't it possible you'd

have more input of pathogens at the sides?

DR. GERBA: That's a small channel. I

mean relative mixing and flow rates and boat

traffic, the large barge traffic, that water

gets stirred up a lot. So --

0090

MS. WILLIAMS: So you concluded it

was --

HEARING OFFICER TIPSORD: Let him

finish.

DR. GERBA: In the large inflow of

water in there. I have based also on the

data sampling, you know, at different depths

in the channel it seems to be fairly well

mixed of what we can see, at least relative

to pathogen levels.

MS. WILLIAMS: So you extrapolated the

degree of mixing from dry weather to conclude

that in wet weather it would be well mixed as

well?

DR. GERBA: It would probably be more

mixed because there is so much flow of water

in there. Water is flowing in there, there's

mixing taking place all the time.

MS. WILLIAMS: Does that conclusion

reflect temperature differences when you have

an influx of wet weather flow?

DR. GERBA: I don't believe this

channel is stratified, to my knowledge.

MS. WILLIAMS: In wet weather do we

0091

know? I mean we don't know, do we? How do

we know?

MR. ANDES: Do you have any basis for

believing that?

MS. WILLIAMS: I'm trying to

understand his basis for believing it's not.

And it sounds like it's -- there isn't one.

DR. GERBA: I don't believe, based on

my experience in the last 30 years of doing

field work on sampling, it should be any

different. And the data in the dry weather

events seemed to certainly confirm that, and

previous studies I've done on different

locations and depths of small channels

doesn't seem to be a big difference.

CHAIRMAN GIRARD: Could I ask just a

clarifying question or summarizing it then?

So do you believe that in the wet

weather, based on measurements and other

information the District might have, there's

a higher flow rate in those streams?

DR. GERBA: Well, if there's more

water input, I would expect that during the

wet weather event I would think that would

0092

increase the flow rate in those channels.

CHAIRMAN GIRARD: How does the flow

rate then impact mixing?

DR. GERBA: There might be more

mixing. There's probably being sediment

material thrown in there, water is being

dumped on the top of the -- or on the bottom,

and so there's going to be a lot of mixing.

And also the boat traffic that goes there

creates mixing events, too.

CHAIRMAN GIRARD: So basically you

assumed faster flow rate, more mixing, so you

only needed one sample point. Is that --

DR. GERBA: Well, based on the

previous data and my experience, too. I

didn't necessarily say that you might have

different levels of pathogens and different

levels -- but I thought that was

representative of the risk, let me put it

that way. I don't think you can have 1,000

times difference in pathogen loading at one

location versus another. Certainly in the

dry weather event there wasn't much

difference between the top water and one

0093

meter depth. You would expect less mixing in

those dry weather conditions. We didn't

really see a difference on that. So I didn't

really actually expect there to be a

difference. I was one of the people who

questioned whether we should be sampling at

one meter depths, because I didn't think

there would be as much difference. And it

turned out there wasn't.

MR. ANDES: There was not?

DR. GERBA: Was not, no.

MS. WILLIAMS: I think you've

answered -- Do you have anything else?

CHAIRMAN GIRARD: That's it. Thank

you.

MS. WILLIAMS: I think you've answered

it pretty well. There's just one piece that

I'd like to make sure I understand. By

choosing to sample only in the center and

also sampling quite a bit downstream from the

actual com stations themselves -- I mean I

understand you sampled as close as you

thought you could, but they were certainly

not right there. There was a distance.

0094

MS. PETROPOULOU: It wasn't where I

thought we could. It's, as mentioned, it was

the captain of the boat that decided that --

MS. WILLIAMS: Okay. What I guess I'm

getting at is are you -- Were you concerned

at all that by not also taking some volume

from the banks that there was input from

gravity CSOs that we missed by going just

into the center that would have been captured

by taking a composite sample from the banks

and the center? Do you understand?

MS. PETROPOULOU: Yes. I don't have

any reason to believe that we overestimated

or underestimated the concentrations of

pathogens. What you are implying is that

during wet weather the concentrations at the

sides could be even higher than what we

measured in the center of the channel. I

mean --

MS. WILLIAMS: It's possible, right?

MS. PETROPOULOU: I have no reason to

believe one way or the other.

MS. WILLIAMS: Thank you. I think

that's --

0095

DR. TOLSON: Let me add one thing to

that. If that were the case, then our risk

estimates would be biased high. So if we

find a -- I'm sorry -- risk estimates in

terms of the effect of disinfection on

decreasing risk to recreators would be biased

high.

MS. WILLIAMS: But the actual risk to

recreators in wet weather would be low,

correct?

MR. ANDES: I think what he's trying

to say is if he didn't capture enough of the

wet weather --

MS. WILLIAM: I understand what he's

trying to say. So I'm asking the risk to wet

weather recreators, though, would be higher

if that were the case, right?

DR. TOLSON: That would be correct.

MS. WILLIAMS: I'm almost done, I

think.

MR. ANDES: I have a follow-up. And

the risk to dry water recreators would be

lower?

DR. TOLSON: It would be unchanged,

0096

but relatively it would be lower, yeah.

MS. WILLIAMS: I'm going to ask

Question 11. I know we sort of touched on

this yesterday, but I'd like to try again.

On Page 6, Paragraph 4 of your

testimony it states, quote, "Disinfection

results in effluent pathogen risk decreasing

from a low level to essentially zero from the

water reclamation plants but has little

impact in waterway pathogen concentrations

affected by current or past wet weather

conditions."

And my question is as TARP is

contemplated and CSO events happen

infrequently, will disinfection have more of

an impact on the waterway pathogen

concentration?

MR. ANDES: I think we've already

objected to other questions about TARP.

HEARING OFFICER TIPSORD: Actually,

they asked and answered this yesterday.

They're not familiar with TARP, so they

couldn't answer the questions.

MS. WILLIAMS: Okay. Can I try to

0097

rephrase it?

HEARING OFFICER TIPSORD: Sure.

MS. WILLIAMS: I believe Mr. Lanyon

testified that TARP was expected or hoped to

reduce CSO events to one to two per year.

MR. ANDES: I don't think that's -- he

mentioned one to two, but I don't think your

characterization is complete.

MS. WILLIAMS: Can you correct it for

me? That would be fine. Would you like to

characterize --

HEARING OFFICER TIPSORD: I think his

comment was in his highest hopes it would be

one to two.

MS. WILLIAMS: No. Highest hope was

relation to my once in every five years. I

thought he expected --

HEARING OFFICER TIPSORD: Let's

just -- How about we do it this way. Why

don't you say what if they were reduced to

four years.

MS. WILLIAMS: Four? That sounds

good. What if the CSO events are reduced

from, I think 43 is what we have now, to

0098

four. How would that --

MR. ANDES: How would that do what?

MS. WILLIAMS: Will disinfection have

more of an impact on the waterway pathogen

concentrations?

DR. TOLSON: The effect of dry weather

in disinfection and overall risk of the

waterway are low under dry weather

conditions. It's below the 8 per 1,000, and

it would stay there. It's very difficult to

try to interpret what the overall effects of

CSOs and of other potential inputs that might

be affected by the completion of the TARP

would be. So I really can't speculate on

that.

MS. WILLIAMS: Let's move on to

No. 18. You state on Page 5 of your

testimony, quote, "It is important to note

that the U.S. EPA has not developed any

secondary contact water quality criteria.

However, the U.S. EPA has proposed a range of

primary contact acceptable risk thresholds,

and currently has primary contact water

quality criteria protective of emersion

0099

activities, that is based on an acceptable

risk threshold of 8 illnesses per 1,000

swimmers."

Do you agree that this 8 in 1,000

risk levels expressed is a water quality

criteria E. Coli value of 126 CFU per 100

milliliters?

MR. ANDES: I'm sorry. Does he agree

with what?

MS. WILLIAMS: Does he agree that that

8 in 1,000 risk level is expressed as a water

quality criteria E. Coli value of 126 CFU per

100 milliliters in the criteria document?

DR. TOLSON: I didn't participate in

that formulation of that, so I'm --

MS. WILLIAMS: So you don't know? Why

don't you take a look at --

MR. ANDES: That's, in part, a legal

question in terms of whether it's a water

quality criterion.

MS. WILLIAMS: It's a legal question

to ask a technical expert what the number is

in a U.S. EPA criteria document? Is that

what you're saying?

0100

MR. ANDES: You didn't refer

specifically to the EPA document. You're

asking about whether it's a water quality

criteria, which is a legal term.

MS. WILLIAMS: Let's just take a look

at Table 5-10. Maybe this will -- from

Exhibit 71. I'm sorry. This is what I'm

referring to when I'm asking. So I'm just

asking if this number here where your table

says 8, and then next to it under E. Coli, 8,

and then 126.

DR. TOLSON: We pulled this out of the

EPA guidance. And I believe it is what it --

it is represented correctly from there, I

believe.

MS. WILLIAMS: Can you tell us what

would be a corresponding ambient standard

that would be protective of incidental

recreational uses that occur in the CAWS as

to 8 illnesses per 1,000 swimmers risk level?

MR. ANDES: Let me first clarify

something, because it's very clear in the

testimony, that the EPA 8 illnesses per 1,000

is not for incidental or noncontact

0101

recreational uses; it's rather a primary

contact number. EPA hasn't developed a

secondary contact number. And you're talking

about swimmers in that statement. So I think

you're mixing apples and oranges. And you're

asking him about, again, an ambient standard.

MS. WILLIAMS: Is that an objection or

a clarification?

HEARING OFFICER TIPSORD: Let him

finish, please, Miss Williams. Go ahead,

Mr. Andes.

MR. ANDES: I think you're also asking

him something that's a legal issue and is

well beyond the scope of their testimony.

MS. WILLIAMS: I don't think it's

legal. That's for sure. If he doesn't know

the answer, that's a different question.

HEARING OFFICER TIPSORD: I was going

to say if -- Since he's already stated he's

not familiar with 126 CFU per 100 milliliter,

if he's unable to answer the next question, I

disagree that it's a legal question also.

MS. WILLIAMS: What I would like to

know, Dr. Tolson, is this: You are telling

0102

us that the risk of recreating this these

waters is well below the risk level that U.S.

EPA utilizes to develop criteria. I would

like to know if we were going to protect

recreators in these waters at that risk

level, what ambient criteria would we have to

establish?

DR. TOLSON: Using an indicator

organism, I don't think we have any data here

to support an indicator organism as being

very related to pathogen and risk. I mean

that's the whole --

MS. WILLIAMS: Okay. So is it the

testimony in this panel that at this current

time there's no good science to use to

establish an ambient standard for protection

of the recreation that's occurring in the

CAWS?

DR. GERBA: Well, it was based on

epidemiological studies that were done by the

U.S. Environmental Protection Agency to come

up with those levels. And they had -- and

that's the basis of -- the scientific basis

for those primary contact recreational water

0103

standards.

DR. TOLSON: So in that respect it

doesn't -- it wasn't produced in quantitative

microbial risk assessment.

MS. WILLIAMS: What wasn't? You mean

U.S. EPA criteria was not?

DR. GERBA: None of those studies, to

my knowledge, or most of them did they look

at pathogens. They only looked at

gastroenteritis illness related to full body

contact swimming.

MS. WILLIAMS: You understand, I'm not

trying to be combative. I really wanted to

know. I mean we are -- this is a state

regulator. We're here to try to figure

out --

MR. ANDES: And I guess to be helpful,

I would say that we definitely have other

witnesses who will help fill in the details

in terms of how we think that such water

quality standard could be developed and will

provide some recommendations in terms of the

path forward that will include Dr. Dorovich,

that will include Dr. Grenado, and others.

0104

MS. WILLIAMS: But they're not talking

about the risk levels, or are they?

MR. ANDES: They'll be talking

about -- actually, Dr. Dorovich will be

talking about risk levels, and Dr. Grenado

will be talking about relations as to what

the regulations should be.

MR. ETTINGER: Just to be clear,

though, looking at 5-10, you've already said

you don't like any of these indicators. So

you don't really agree with the EPA E. Coli

and enterococci numbers anyway?

DR. GERBA: I didn't say I didn't like

them. I said that's what's used right now.

I said in the future, I think, my

professional opinion is that some pathogen

like adenoviruses might be included in there,

but the standards are what they are.

MR. ETTINGER: Well, I'm not asking

you a legal question. I'm just saying as a

scientist, you don't think these numbers are

correct. You think EPA's numbers here are --

that their correlators are not useful?

DR. GERBA: I think their data is

0105

correct. I think they did epidemiological

studies on it. I'm not questioning their

data or their -- I'm just saying in the

future, additional parameters may be added,

though, to assess the water quality in the

future. That's all I'm saying.

MR. ANDES: If I can clarify.

DR. GERBA: That's my opinion.

MR. ETTINGER: If you want to clarify

it, please do. Because I thought we went

over this somewhat. And I took away from

that that you didn't think that there was any

particular relation between pathogens and

E. Coli or pathogens and enterococci, and now

I'm hearing something else.

MR. ANDES: I think the first issue is

is that the EPA numbers that have been

discussed are with reference to primary

contact.

DR. GERBA: Right. That's correct.

MR. ANDES: Okay. In terms of the

questions that have been asked of you

regarding secondary contact regarding the

types of recreation that are being proposed

0106

here, the first question is do you see a

clear link between any of these indicators

and actual pathogen levels that would cause

illness?

DR. GERBA: No. Because there's --

can't find a relationship between the

indicators and the pathogen levels in the

water.

MR. ETTINGER: That was my point. As

far as you're concerned, these numbers aren't

even good for swimming.

DR. GERBA: I didn't say that.

MR. ANDES: He's speaking particularly

about secondary contact uses with regard to

the study at issue here.

MR. ETTINGER: Why would the

correlation or lack of correlation between

enterococci and pathogens differ whether you

were considering it for secondary use or

primary use? I mean the bugs are there or

they aren't. So I guess I'm just not

following.

DR. GERBA: It's related to the degree

of exposure. Exposure is a lot less than a

0107

secondary contact.

MR. ANDES: I don't think, Albert, I

don't think that this group is here to defend

EPA science behind their criteria.

MR. ETTINGER: I'm not asking them to

defend it. I'm asking them to say whether

they agree with it or not as scientists.

MR. ANDES: But are you talking about

the levels or are you talking about the

specific parameters? I think there are two

different issues.

MR. ETTINGER: If I had a higher

number of E. coli, would you say that I have

a higher level of pathogens or not?

DR. GERBA: No, not necessarily.

MR. ETTINGER: And if I have a higher

level of enterococci, do I have a higher

level of pathogens or not?

DR. GERBA: No, not necessarily.

MR. ETTINGER: So you would conclude,

I would think, that this chart, which assumes

there is some relationship between these

indicators and pathogens in the water, is

misguided.

0108

DR. GERBA: That does not assume that.

What that -- that standard is based on

epidemiological data related to

gastroenteritis among the swimmers, not the

pathogen levels.

MS. WILLIAMS: Can I ask -- I don't

want to interrupt, but I just -- you left out

fecal. Can I just ask the same -- if you

have a higher level of fecal coliform in the

water, do you have a higher level of

pathogens, just to complete the --

DR. GERBA: Not necessarily.

MS. WILLIAMS: Sorry, Albert.

MR. ETTINGER: Let's go back, just

talk about swimmers here. Pathogens are

making the swimmers sick, right?

DR. GERBA: We don't know that for a

fact. It could be nonpathogens that make the

swimmers sick because they didn't do any

follow-up on whether it was illness. It

could be they ate too many hot dogs on the

beaches, it could be on some of the beaches

and that; or it could be the air was

different. Perhaps there are allergens or

0109

other substances people might inhale and

react to on the beach. It's been brought up

before that it could be made toxins from blue

green algae aerosolized and inhaled. Because

in this type of research they did not

actually identify the agents causing

gastrointestinal illness. So all of it may

not be due to pathogens. The assumption here

is that it is due to pathogens. What's

regulated here is the probability -- the

probability based on that 126. If you get

gastroenteritis, it's not necessarily by

swimming in these waters, not necessarily

related to a pathogen; regulating swimming

and diarrhea.

MR. ANDES: Let me take another shot.

MR. ETTINGER: Let me just -- It's my

turn. There is some sort of statistically

significant relationship between enterococci

and how many swimmers get sick. Is that true

or false?

DR. GERBA: In terms of

gastroenteritis, yes.

MR. ETTINGER: There is, okay. Unless

0110

the -- maybe I'm confused. But unless there

is some relationship between enterococci and

the number -- in the water and the number of

hot dogs they ate on the beach, that's

probably not a factor that's driving that.

DR. GERBA: I wouldn't presume so.

But, again, they did not identify that a

pathogen actually caused that illness or

which pathogen did, so that's still an

unknown.

MR. ETTINGER: So your objection is

really that this is a black box model. You

go from enterococci to illnesses and you're

not tracing the causation.

DR. GERBA: Right. At least in my

professional opinion in the future people

need to do studies on characterizing what

caused the illness and what pathogens were in

the water that bathers were exposed to.

MR. ANDES: I believe, correct me if

I'm wrong, but I believe the reasons these

numbers were used in this study simply as a

point of reference that was available, a

conservative point of reference, the lowest

0111

risk threshold identified by the EPA to be

used as sort of a screening level to identify

where risks were low. Am I correct?

DR. GERBA: That's right.

DR. TOLSON: That's correct.

MR. ANDES: So there was nothing

intended in terms of the report indicating

the technical validity of those numbers,

particularly with reference to secondary

contact.

DR. GERBA: That's correct.

MR. ANDES: Thank you.

HEARING OFFICER TIPSORD: All right.

This is probably a good point to take a

break. It is my intention to stay this

evening until we finish with this panel so

that they don't have to come back in

September. So you may want to get a snack

depending upon how many questions we have.

(Short break taken.)

HEARING OFFICER TIPSORD: We can go

ahead. And, Miss Williams, you wanted to

make a motion on the record?

MS. WILLIAMS: I wanted to briefly

0112

make a motion on the record to request an

additional two-week extension to submit

prefiled questions for the Midwest Generation

witnesses, and I have spoken to Midwest

Generation. They're agreeable to that.

HEARING OFFICER TIPSORD:

Mr. Ettinger, you wanted to join in that? I

would be inclined to grant that and give that

to everyone. So just so you all know, I will

do that in a hearing officer order. When I

do the separate hearing order for the

remaining five hearings we have scheduled;

for now, the five hearings.

And with that, Miss Williams,

you had one more question, I think you said,

one or two?

MS. WILLIAMS: So when we left off we

were talking about the different indicators

and whether they are correlated to pathogens.

So, Mr. Gerba, can you tell us whether

pathogen concentrations are correlated to

risk of illness?

DR. GERBA: That's what the dose

response curve say that they generated in

0113

human beings.

MS. WILLIAMS: Is that what you used

to develop your risk assessment?

DR. GERBA: That's part of the

process, but I didn't do the risk assessment.

MS. WILLIAMS: Okay. Is that what you

used, Mr. Tolson, to develop the risk

assessment?

DR. TOLSON: That is correct. We

used established dose response curves for

pathogens under this study.

MS. WILLIAMS: You were --

DR. TOLSON: Want me to repeat that?

MS. WILLIAMS: It was kind of hard to

hear.

DR. TOLSON: We used established dose

response parameters for the pathogens under

investigation in the study. Mostly people

tell me not to talk so loud.

MS. WILLIAMS: And you, in your

testimony, say that you're a risk assessment

specialist. Does that sound right?

DR. TOLSON: That is correct. That's

one of the major components of my practice.

0114

MS. WILLIAMS: Do you agree that an 8

in 1,000 risk of illness is a good target for

recreational activity?

DR. TOLSON: I really can't evaluate

how or why EPA selected that. I just took

the EPA promulgated established number of

eight and used that to sort of characterize

our risk within our report.

MS. WILLIAMS: If they change the risk

assessment level they relied on, would you

have an opinion on that?

MR. ANDES: Up or down?

MS. WILLIAMS: Either.

DR. TOLSON: We could characterize it

compared to that new number.

MS. WILLIAMS: If they changed it to

one illness per 1,000 recreators, would you

have an opinion on that?

DR. TOLSON: If we use that as our

benchmark, then we would compare our numbers

to that number. Yeah, sure. It's just a

benchmark number out there.

MS. WILLIAMS: I think that's all I

have.

0115

HEARING OFFICER TIPSORD: Thank you,

Miss Williams. Before we continue, I would

note that these are prefiled questions that

are mainly for Dr. Tolson.

MS. MEYERS-GLEN: That is correct.

HEARING OFFICER TIPSORD: As we

discussed off the record, Dr. Gerba has a

flight and must leave no later than 5:30. So

basically what I'm trying to get at is there

shouldn't be a problem with him going ahead

if we're not through, do you think?

MR. ANDES: Depends on, I guess, some

of those questions are being answered by the

panel.

HEARING OFFICER TIPSORD: Let's start

and we'll see where we're at.

MS. MEYERS-GLEN: I have no problem

with that. Because my questions are

predominantly --

HEARING OFFICER TIPSORD: Okay.

MS. MEYERS-GLEN: My name is Stacy

Meyers, and I'm with Openlands.

HEARING OFFICER TIPSORD: Keep your

voice up, please.

0116

MS. MEYERS-GLEN: Dr. Tolson, we were

discussing different literature that you

combined with UAA survey data on existing

recreational uses. You named two of them,

one being Flat Water Classic and then the

other reference to some rental facility. And

in Question No. 1, I was wondering if you

could please cite to the literature that you

combined with the UAA survey including those

and in addition to those in formulating your

parameters for recreational uses.

DR. TOLSON: The UAA was the principal

study for which all the analytical or

quantitative evaluation was performed. It

was ground truthed with some other data that

we pulled in including the data that you

cited there.

MS. MEYERS-GLEN: What is that other

data?

DR. TOLSON: That would be Flat Water

Classic, boat rental receipts that IEPA were

able to provide us to show that, you know,

these are all the activities that were

ongoing within the waterway.

0117

MS. WILLIAMS: Did that UAA data hold

up to this ground truthing?

DR. TOLSON: Yes, it did. We had

information that said that there was

additional canoeists, and we've had data that

said there were additional boating. And the

UAA data said that there was canoeing and

boating going on. It seemed consistent with

that.

MS. MEYERS-GLEN: What boat rental

facility was that?

DR. TOLSON: I do not recall the boat

rental facility, but we actually received

that information from someone at IEPA, and I

believe we cited that as a communication or

something to that sent in the report.

MS. MEYERS-GLEN: Is there any way I

can find that out, the name?

DR. TOLSON: I'll find it out in a

second.

HEARING OFFICER TIPSORD: Excuse me.

Off the record for just a second.

(Off the record.)

HEARING OFFICER TIPSORD: Back on the

0118

record.

MS. MEYERS-GLEN: I don't need it now.

If you could just provide us with the name,

that would be great, just to for expediency

just to keep going.

MS. WILLIAMS: I think -- I mean do we

think it was Rob Sulski? Is that it?

DR. TOLSON: I believe.

MS. MEYERS-GLEN: Can you just -- as

long as I get the information that --

MR. SULSKI: It's one of the exhibits.

It's the additional data beyond the UAA,

Additional and Extra Recreational Data,

Sulski IEPA, something like that.

HEARING OFFICER TIPSORD: And it's

attached to the?

MR. SULSKI: It's attached to --

HEARING OFFICER TIPSORD: To Exhibit

71?

MR. SULSKI: No. It's an earlier

exhibit that is besides the UAA report. And

it was a compilation of e-mails and

correspondence between various users, and it

was a compilation of additional data.

0119

MS. MEYERS-GLEN: Is that the IEPA

Attachment No. K, Recreational Data --

MR. SULSKI: That is it.

HEARING OFFICER TIPSORD: Attachment K

to the proposal.

DR. TOLSON: I don't know if that's

exactly the one or not, but I'll get the

information on the data that I was referring

to. I suspect that we're talking about the

same thing, but you may have a larger data

set than that was supplied to me. So I just

want to make that clear that I don't know

exactly that that's the right one, but I

think is.

MS. MEYERS-GLEN: Thank you. Question

No. 2, on Pages 2 and 3 of your testimony you

state that, quote, "We assume that incidental

ingestion by an individualist canoeing on the

waterway will vary over a range and

calculations that are performed account for

all users even those that might capsize."

Did you determine what risks were

specifically attributable to the percentage

of the people who capsized when canoeing or

0120

kayaking on the CAWS?

DR. TOLSON: I believe we covered

this, but we developed an ingestion range

that included the potential for high exposure

and low exposure. But we did not develop

specific risk estimates for a capsizing

canoeist within the waterway.

MS. MEYERS-GLEN: Thank you. No. 3

was partially answered. I know that you gave

a breakdown yesterday of what stretches of

the CAWS were included in each of the three

segments in your study. Do all the waterways

in each segment have identical

characteristics?

DR. TOLSON: I would say that there's

differences that are either continuous

difference along every foot of the CAWS way,

yeah. There are some differences, physical

or otherwise.

MS. MEYERS-GLEN: And I believe it was

your testimony as well that there were

certain waterways that were combined into

segments closer to outfalls?

DR. TOLSON: There are some areas that

0121

are closer than others, sure.

MS. MEYERS-GLEN: Did you average in

waterways that are not proposed for

incidental contact recreational use when

calculating risk for canoeing?

DR. TOLSON: No. To my knowledge all

of the data that was collected as far as

analytical data of pathogens within the

waterway and all the exposure data that we

developed from the UAA was all within the

waterway segments that we identified

yesterday.

MS. MEYERS-GLEN: So you only assessed

incidental contact waterways?

MR. ANDES: Want to specify which

waterways you're talking about?

MS. MEYERS-GLEN: Well, what I'm

asking is that did you break down all of the

CAWS into three segments in the study, all

the CAWS being all of the stretches of the

Chicago area waterways at issue in this

study?

MR. ANDES: Specifically you're asking

whether he would include the few areas that

0122

were not proposed for incidental contact

recreational use?

MS. MEYERS-GLEN: I'm saying did you

include everything from the Wilmette pumping

station on the North Shore Channel all the

way down the Chicago Sanitary Ship Canal down

to the Brandon Street Lock and Dam as well as

the Cal-Sag Channel all the way out to the

Calumet River extending out to the Lake

Michigan? Did you include all of those

waterways that are considered to be the CAWS

total in the UAA?

DR. TOLSON: I don't think so. So we

did not include the Grand Calumet, which I

think would be included within what you're

looking at there. We just included the

little Calumet. There may have been some

other branches in there that we did not

include, but we based our use information and

our sampling points, as we've shown, within

the waterways that we're representing the

risks that are presented in Exhibit 71. If

there's a specific segment that you have

there which is noncontact that you'd like me

0123

to address, just say it and I'll let you

know.

MS. MEYERS-GLEN: Sorry. I was just

looking at exactly where this starts and

where this ends. Did you include the Chicago

Sanitary and Ship Canal from the confluence

of the Calumet Sag channel down to the

Brandon Street Lock and Dam?

DR. TOLSON: We do not have any

analytical data, any microbiological data

from the confluence south. So, no, it does

not represent that. My speculation is that

the pathogen loads are actually lower there

than they are in other places just because

they're further away from the city CSO

outfalls, pumping stations, other things.

MS. MEYERS-GLEN: So it wasn't

included in your study?

DR. TOLSON: No.

MS. MEYERS-GLEN: On Page 8 of the

executive summary in the microbial risk

assessment study -- this is Question 4. The

Geosyntec consultants performed for the

district, it states that the Chicago area

0124

waterways are used for recreational boating,

canoeing, fishing, and other streamside

activities. Can you tell us what other

streamside recreational activities occur in

the CAWS? What does that mean?

DR. TOLSON: Which question are you

reading here?

HEARING OFFICER TIPSORD: Question 4

on Page 2.

DR. TOLSON: So the other streamside

activities, there were identifications within

the UAA of passive recreation and other

things, I imagine, that those would be other

streamside activities; walking along the

waterway would be one. But these are

activities that one was not associated with

actually contact of the water into the

exposure groups that we identified as the

high exposure characteristic of canoeing, the

medium exposure, characteristic of fishing,

the low exposure, characteristic of boating.

MS. MEYERS-GLEN: And you said earlier

that you used the UAA study as the basis for

recreational uses, what recreation uses you

0125

chose, correct? That was the foundation?

DR. TOLSON: That is correct.

MS. MEYERS-GLEN: And so in the UAA

you would agree that would include canoeing,

sculling, hand-powered boating, fishing,

wading, skiing, tubing, swimming, diving, and

jumping, correct?

MR. ANDES: Are you saying did they

assess all of those?

MS. MEYERS-GLEN: That is what the UAA

study reported as recreational uses along the

CAWS. And since that is the foundation of

the study as far as what recreational uses

they determined were out there, I just wanted

to verify that looking at the universe of the

recreational uses.

DR. TOLSON: Right. We identified the

secondary contact recreational -- incidental

contact recreational uses that were in the

UAA. So we did not include swimming within

our groupings that we assessed.

MS. MEYERS-GLEN: Okay. But it did

include canoeing, sculling, hand-powered

boating, fishing, wading, skiing, and tubing,

0126

correct?

MR. ANDES: Tubing.

DR. TOLSON: Tubing is not included in

there. There is another one, jumping and

something else. Skiing was in there, that

was one that we didn't include within our

grouping. Those are primary contact

activities. We would associate those with

primary contact activities.

MS. MEYERS-GLEN: I'm going to come

back to that particular point.

So in your opinion, the

activities listed in the UAA study are

occurring on the CAWS then, correct? That's

really not --

DR. TOLSON: We're not going to have

any basis for that.

MS. MEYERS-GLEN: Now, the Geosyntec

study refers to worse premise and I know that

we covered this in some part, worse premise

that disinfection is warranted in situations

where direct human contact in the immediate

vicinity of an outfall is possible. And I

just wanted to be clear: People can canoe,

0127

kayak, jet ski, or tube past these wastewater

treatment plant outfalls to your knowledge,

correct?

DR. TOLSON: I think we covered that

quite a bit with Dr. Gerba's explanation of

it.

MR. ANDES: I believe this issue of

what the direct contact is has already been

covered by Dr. Gerba.

MS. MEYERS-GLEN: I didn't say direct

contact at all. I just wanted to know if

they could kayak, canoe, or jet ski past on

these waterways the wastewater treatment

plant outfalls.

DR. TOLSON: There is no physical

limitations to people going down the

waterway, to my knowledge.

MS. MEYERS-GLEN: And then on Page 96

of the Geosyntec study it states that it is

unlikely that users engage in nonemersion

activities -- that users engage in

nonemersion activities would be subject to

levels of inhaled mists or sprays that will

lead to a substantial increased ingestive

0128

dose. And I know that we covered that with

Ann Alexander as far as how you all assessed

ingestion. I believe your Attachment 3, the

risk study, Page 96, is where that quote

lies. My questions to you are that did you

consider how spray could increase the

ingested dose for jet skiers?

DR. TOLSON: We did not attempt to

calculate ingestion for jet skiing and

inhalation and subsequent swallowing of

sprays.

MS. MEYERS-GLEN: And you also didn't

consider that for people that tube on the

CAWS, correct?

DR. TOLSON: Say that again?

MS. MEYERS-GLEN: And you also didn't

consider that for people that are engaged in

tubing on the CAWS either, correct?

DR. TOLSON: Tubing was not one of

the --

MS. MEYERS-GLEN: Right.

MR. ANDES: I'd like to follow-up.

MS. MEYERS-GLEN: So, no, that wasn't

considered, correct?

0129

DR. TOLSON: Tubing was not considered

as one of the activities that was one of the

exposure groups that we looked at.

MS. MEYERS-GLEN: Right. But yet it

was listed in the UAA as one of the

recreational uses out on the CAWS, correct?

DR. TOLSON: I believe it was listed

in the UAA. It was not grouped in one of our

exposure groups.

MS. MEYERS-GLEN: Right.

MR. ANDES: I'd like to follow-up on

those two questions, and this could be either

Dr. Gerba or Dr. Tolson. If you can give us

your judgment as far as you believe that the

dose the jet skiers or tubers spray would be

at all significant?

DR. TOLSON: I do not believe so. We

actually tried to estimate what that could

be. And if you look at a cloud, which is a

pretty high mist-containing environment, you

get about a half a mil per cubic meter in the

air. So if someone were to breathe about a

cubic meter per hour, that would give you

about half a mil per hour ingestion rate. So

0130

that is not nearly as high as some of the

numbers we have as ingestion rates per hour

for our exposures, and we felt that that was

not really significant. We also don't think

that there's mists out there to the level

that would rise to a cloud.

MR. ANDES: Thank you.

MS. MEYERS-GLEN: I'm just going to

ask one simple question. Jet skiing, though,

can kick up spray, correct?

DR. TOLSON: Yes, it can.

MS. MEYERS-GLEN: I'm just going to

introduce what has already been attached as

Openland's attachment number -- may I?

HEARING OFFICER TIPSORD: We're going

to mark this as Exhibit 82, if there's no

objection. It's the attachment one to

Openland's questions. Seeing none, it's

Exhibit 82.

MS. MEYERS-GLEN: That's the one that

was attached to my prefiled testimony, too.

That's just showing the amount of spray

actually kicked up by a jet ski. And that

wasn't accounted for, correct, in the study?

0131

DR. TOLSON: There was -- We did not

estimate dose for jet skiers within our

analysis, nor did we estimate dose from

sprays for any of our exposure scenarios.

MS. MEYERS-GLEN: Okay. So then it

wouldn't -- You wouldn't know then the

increased risk -- you didn't study the

increased risk for respiratory infection from

an activity like that?

DR. TOLSON: I think we've been over

this. We did not evaluate respiratory

infection within the context of our risk

assessment. That was not one of our stated

objectives here.

MS. MEYERS-GLEN: And I'm turning

specifically to your Attachment 3, the risk

study, Page 133 --

HEARING OFFICER TIPSORD: For the

record, when you are talking about

Attachment 3, Attachment 3 to Tolson's

testimony?

MS. MEYERS-GLEN: That is correct.

Thank you. Why did not did you not account

for intimate exposure of your areas that

0132

might produce considerable mist such as

aeration stations? It's Page 133.

DR. TOLSON: Okay. This is for

respiratory illness associated with exposure

to aeration stations. Is that what you're

referring to?

MS. MEYERS-GLEN: That is correct.

DR. TOLSON: The study did not

evaluate respiratory risks. The focus was on

GI illness. In addition, the data on

exposure associated with those aerosols that

might arrive from the aeration stations is

unknown. We do not have a way of quantifying

a dose. So even to do the GI component of

that, it proves problematic. We believe

based on our assessment of what you could

potentially contain in a mist that you could

inhale that a dose would be low even if you

were immersed in it.

MS. MEYERS-GLEN: I'm going to, just

second part of D, yet there is incidental

contact activity such as jet skiing,

kayaking, canoeing, tubing, and sculling in

the stretches of the CAWS that could occur

0133

near the aeration standards, correct -- or

the aeration stations. Sorry. Correct?

DR. TOLSON: Yes. I do not know.

HEARING OFFICER TIPSORD: For the

record, Attachment 3 is Exhibit 71. It is

the report that we've been discussing, and we

should be clear on that. Because I, frankly,

was a little lost.

MS. MEYERS-GLEN: Okay. Going with my

prefiled questions and I --

MR. ANDES: To follow-up on the

aeration station issue, and whether these are

within your knowledge. If not, we may ask

this question later of district witnesses.

First, are you aware of safety issues in

boats near the aeration stations in terms of

the bubbling water in those areas?

DR. TOLSON: Actually, I do not know

that. I've been told that, but I'm not the

best witness for that. Sorry.

MR. ANDES: Okay.

MS. MEYERS-GLEN: No. 7, the report

also -- the microbial risk assessment

0134

Exhibit 71 also states that jet ski use is

typically thought to involve immersion, and,

thereby, would not be allowed under the

conditions of the waterway. However, large

jet ski boats would be allowed, and I believe

that is Exhibit 71 at Page 97. My questions

to you are this: Are you aware that the IEPA

did not list jet skiing in the UAA as a

primary contact activity; and although

borderline distinguished it from water skiing

in its statements of reasons as having a

lower likelihood of ingesting appreciable

amounts of water?

MR. ANDES: Are you asking him to

characterize the IEPA document?

MS. MEYERS-GLEN: Are you aware of

that? No. That's actually out of the IEPA

statement of reasons. And I was wondering,

since he's stating that in calling jet skiing

primary contact and relied on the UAA,

whether or not he was aware that it lists jet

skiing as a primary contact -- it does not

list jet skiing as a primary contact

activity, and although borderline,

0135

distinguishes it from water skiing as having

a lower likelihood of ingesting appreciable

amounts of water.

MR. ANDES: I can read that, too. But

I would disagree with your characterization

of the statement from the statement of

reasons. If we want to read him the

statement from the statement of reasons

verbatim, that would be fine. I think it

says something very different.

MS. MEYERS-GLEN: Sure. Absolutely.

I can read you both segments, if you can hold

on one second.

MR. ANDES: While we're waiting, if I

can follow up on one question. Is it your

understanding primary contact activities are

not included in the proposed uses as

designated by Illinois EPA?

DR. TOLSON: That is correct.

MR. ANDES: Thank you.

MS. MEYERS-GLEN: Okay. And to follow

that, if we can actually start on Page 42 of

the statement of reasons. I'm going to read

you the definition of primary contact from

0136

this, okay? Primary contact recreation is

typically defined by states to encompass

activities that could be expected to result

in the --

HEARING OFFICER TIPSORD: You need to

slow down.

MS. MEYERS-GLEN: Absolutely.

Ingestion of or immersion in water such as

swimming, water skiing, surfing, or any other

activity where immersion in the water is

likely. Now, we can agree that jet skiing is

not included in that statement, correct?

MR. ANDES: I think you're --

HEARING OFFICER TIPSORD: But the

Footnote 3 --

MR. ANDES: -- characterizing the

testimony.

MS. MEYERS-GLEN: I'm about to get

there. But in that list of primary contact

they do not include jet skiing, correct?

DR. TOLSON: I'm not sure I -- I'm not

sure I believe that. I think there's a

footnote that's associated with that.

MS. MEYERS-GLEN: There absolutely is.

0137

But I want to take one step at a time. They

list out primary contact uses; is that

correct?

DR. TOLSON: There are probably a

number of other primary contact uses that are

not listed on there.

MS. MEYERS-GLEN: Okay. But in this

list it does not include water skiing,

correct?

HEARING OFFICER TIPSORD: Jet skiing.

MS. MEYERS-GLEN: Jet skiing. Thank

you.

MR. ANDES: It includes a general

statement at the end.

MS. MEYERS-GLEN: Yes. But we're

going to get there one step at a time. It

does not include -- It includes water skiing,

though, right?

DR. TOLSON: I believe so. I don't

have it in front of me, but, yeah, I take

your word on it.

MS. MEYERS-GLEN: But it doesn't

include -- even though it includes water

skiing, it doesn't include jet skiing,

0138

correct?

HEARING OFFICER TIPSORD: That's the

third time you've asked that and the third

time he's answered it.

MS. MEYERS GLEN: I haven't gotten an

answer yet.

HEARING OFFICER TIPSORD: Yes. He

said that's correct.

MS. MEYERS-GLEN: Thank you. I didn't

hear. Now, there is a footnote on Page 43

that says kayaking and jet skiing may be

borderline recreational activities that many

lump into primary contact but likely do not

involve its high likelihood of ingestion of

appreciable amounts of water as swimming,

water skiing, and surfing. Okay. Can we

agree that that's what this says?

DR. TOLSON: I believe that this is,

in fact, what that says, yes.

MS. MEYERS-GLEN: So is it your belief

then that IEPA, after hearing this, that IEPA

considers jet skiing to be a primary contact

activity?

DR. TOLSON: Based on the footnote

0139

where it says many believe, I guess I would

include myself in the group of many.

MS. MEYERS-GLEN: Okay. So -- all

right. So then why do you choose to restrict

the study to use of larger jet ski boats when

the IEPA did not place such a distinction on

jet skiing?

DR. TOLSON: I've actually toured the

waterway, and my one occurrence with a jet

boat out there did not look like the picture

that you have here. And I'm --

MS. MEYERS-GLEN: That's not my

question, though. My question is why did

you --

HEARING OFFICER TIPSORD: Would you

let him finish his answer before you

interrupt him, please.

DR. TOLSON: My observations of jet

boats in the one occurrence that I did see

one was a two-man boat. The guys were in

collared shirts, I believe, and straw hats

kind of stuff. And it made me think maybe we

could be misinterpreting the UAA study. I'm

not sure if they included these guys as jet

0140

skiers or not. So kind of to be conservative

to make sure we captured all the uses we

could out there, we just lumped the few

observations of jet skis that we saw in the

UAA, we put them under the boating so it

would be included in there. Because we were

really unsure whether they were this guy jet

skiing or the guys that we'd observed on the

waterway that were jet skiing in really kind

of bigger boats.

MS. MEYERS-GLEN: The jet ski in front

of you, would you consider that to be primary

or secondary contact? I'm referring, just

for the record, to the attachment that I --

HEARING OFFICER TIPSORD: Exhibit 82.

DR. TOLSON: Primary contact, because

the guy doesn't look very sure of himself. I

think he may fall off at any moment.

MS. MEYERS-GLEN: So it's not the

activity, but the fact that that particular

jet skier would fall off that's making that

distinction?

DR. TOLSON: I think the distinction

is that the person on this boat is having --

0141

likely to have a high contact with water.

We've grouped our exposures into those that

have primary contact water that we've

excluded from our analysis. This would be an

activity I think that he has a life preserver

on there, somebody who would have full body

emersion, and it would not be one of the

receptor scenarios that we've developed risk

numbers for within our report.

MS. MEYERS-GLEN: If somebody is

wearing a life preserver on a two-seater,

then that would be included as secondary

contact?

DR. TOLSON: I think, you know, I'm

trying to characterize within our receptors

to include those jet skiers. Because my one

observation of a jet boat on the waterway was

one where the occupants certainly didn't look

like they were going to have full body

emersion. If you would like, I can provide

you a picture of that. I actually took a

picture of them as we went by them on the

waterway.

MR. ANDES: I thought we had them.

0142

MS. MEYERS-GLEN: I'm just trying to

understand where your line is as far as which

jet skiers are included in secondary contact

and which jet skiers are included in primary

contact. That's all. Because it seems like

there is some in one category and some in the

other.

HEARING OFFICER TIPSORD: Is there --

DR. TOLSON: We did not try to

characterize the specific activity where

anybody was occurring. We developed these

risk ranges that had ingestion rates that

were kind of a big range. That being said,

there were very few jet skis that were

identified within the UAA. We included them

in boating because there was a potential that

if we didn't include them in boating, perhaps

these -- we're talking about these two-man

boats or larger boats that we didn't want to

underrepresent within the study. I would

characterize this particular activity that

this gentleman is engaged in as a primary

contact activity. But this is really outside

of my realm of identifying primary contact

0143

activities and secondary contact activities.

It's not what I do.

MS. MEYERS-GLEN: You guys made a

call, though, as to whether or not to include

that activity?

DR. TOLSON: We had to take that

handful of receptors and try to characterize

them within the categories which we laid out

within Exhibit 71, our risk assessment. We

made the call that the boats -- that the jet

skis could possibly be boats. We wanted to

make sure we included anything that was

potentially a recognized activity in the

waterway, we included them within that group.

MS. MEYERS-GLEN: Yet if you're saying

that you included it as a recognized

activity, you also did not include swimming,

correct, and that was a recognized activity?

DR. TOLSON: A recognized activity is

more of a legal term that I probably

shouldn't be invoking or else -- that's true.

It was primary contact. We felt swimming was

one that ought to be included.

MS. MEYERS-GLEN: But it was a

0144

recognized activity. It was something in the

UAA as listed as occurring, correct?

MR. ANDES: I'm going to really object

to this argumentative line of question. He's

answered the questions. He told you what he

included and why.

MS. MEYERS-GLEN: Well, I'm confused

in that he stated that he included it because

it was a recognized activity on --

MR. ANDES: That's not what he said.

MS. MEYERS-GLEN: That's exactly what

he said. So I'm curious then as to why he

then did not include other recognized

activities such as swimming.

DR. TOLSON: Another reason is the RFB

for which we were responding to developing

this clearly stated and listed those

activities and how we would categorize them.

Jet skiing was not included within that list.

MS. MEYERS-GLEN: Thank you.

DR. TOLSON: Swimming was not

including with that list. I'm not sure if it

said anything about jet ski.

MR. ANDES: Did it say that primary

0145

contact activities were not to be included?

DR. TOLSON: That's correct. Primary

contact activities was not included.

MR. ANDES: Swimming is clearly

primary contact. You decided not to include

it?

DR. TOLSON: That's correct. Swimming

is primary contact. It was not included.

MR. ANDES: Because the two-person

boats were unclear, you decided to include

them as boats?

DR. TOLSON: That is correct.

MR. ANDES: Thank you.

MS. WILLIAMS: Can I follow-up,

please? Just since I wrote Footnote 3, I'd

like to follow up by making sure I understand

what you said here. You are saying you

consider yourself someone who generally

considers jet skiing, at least as conducted

in this exhibit, primary contact activity

generally?

DR. TOLSON: That's my opinion.

MS. WILLIAMS: Thank you.

MS. MEYERS-GLEN: One more question

0146

along those lines. Although the resulting

risk estimates do not account for such, did

you seem to calculate how much more jet

skiers likely to ingest appreciable

quantities of water than a person canoeing?

DR. TOLSON: We did not include

primary contact jet skiing as an activity

that we developed, no.

MS. MEYERS-GLEN: Did Geosyntec

analyze exposure rates for kayaking, tubing,

or sculling in comparison to tubing?

MR. ANDES: What kind of --

HEARING OFFICER TIPSORD: That's D.

MS. MEYERS-GLEN: 7D.

HEARING OFFICER TIPSORD: For the

record, I think we've -- he's repeatedly

stated that he did not consider tubing.

DR. TOLSON: That is correct. We did

not consider tubing.

MS. MEYERS-GLEN: Then kayaking or

sculling in comparison to canoeing.

DR. TOLSON: We didn't calculate an

exposure rate for each individual activity.

We developed a range of exposure rates for

0147

which canoeing could be kind of the

representative activity, and that was a

distribution that ranged from high

potentially capsizing events to low.

MS. MEYERS-GLEN: Do you know whether

or not the exposure, the risk of exposure is

higher for kayaking or sculling than

canoeing?

DR. TOLSON: We don't have any data to

support that. So, no, I don't know.

MS. MEYERS-GLEN: Could somebody in a

kayak have a higher risk than someone in a

canoe of exposure?

DR. TOLSON: They think could have a

risk for a number or reasons. That's

correct. Somebody in a canoe could have a

higher risk than somebody in a kayak.

MS. DEXTER: Why did you choose

canoeing as the representative activity?

DR. TOLSON: I believe it was -- It

seemed like a reasonable thing to call that

high contact activity. I believe the UAA has

canoeing and kayaking as one group there, so

to eliminate a lot of dashes within the

0148

report, we called it canoeing.

MS. DEXTER: Did you have data on the

canoeing? Was there -- Was there data to

support the canoeing?

MR. ANDES: I think he already

answered that question. It was ingestion

rates; high, medium, and low ingestion rates.

MS. MEYERS-GLEN: Was there a

difference in ingestion rates when looking to

choose a representative for high contact in

your study? Was there a difference in

ingestion rates for canoeing and kayaking?

DR. TOLSON: Again, I think that

misrepresents what we're doing. We're just

coming up with three sort of exposure groups.

We've called that high exposure group

canoeing which is sort of a representative

recreational activity associated with the

high. We didn't develop kayaking as, you

know, 12.2 and canoeing as 12.3. There's no

number that's associated with each individual

thing and some together. We developed a

distribution, a range, that incorporated all

these sort of higher exposure activities.

0149

MS. MEYERS-GLEN: So you treat the

risk as the same?

MR. ANDES: Same as what?

MS. MEYERS-GLEN: For canoeing,

kayaking, and sculling; all of those

activities, the risk is treated as the same,

correct? It's all considered to be high

contact of the same risk?

DR. TOLSON: The category of higher

exposure activities along the waterway. And

had we not looked -- I don't think sculling

was specifically called out within the UAA,

so there would have been no way for us to

tease out sculling versus the canoeing or

kayaking. So there's a necessity for sort of

grouping activities together.

MS. MEYERS-GLEN: Do you know whether

sculling occurs on the CAWS?

DR. TOLSON: I have not seen it. I

understand it does.

MS. MEYERS-GLEN: And 8 is asked and

answered.

Nine, in quantifying the

amount of water ingested -- Wait a minute.

0150

Sorry. I'm going to stop. Nine is asked and

answered. Withdraw.

Ten. I just need a second. I

want to see if this is asked and answered.

Ten is partially asked and answered.

You stated earlier that the

ingestion rates for fishing and boating were

adjusted downwards using professional

judgment, is that right, from canoeing?

DR. TOLSON: That is correct.

MS. MEYERS-GLEN: And was that your

professional judgment used to set the rate?

DR. TOLSON: We met collectively as

the Geosyntec team and our expert panel and

discussed these matters. I think it was

arrived to by consensus.

MS. MEYERS-GLEN: 11, when discussing

how the risk assessment accounted for

exposure duration, the report states that

assumptions regarding length of time an

individual might be on the waterway are

required; activity based assumptions were

developed for this exposure input based on

waterway specific information where available

0151

and professional judgment guided by literary

references. This is Exhibit 71, No. 101,

Page No. 101.

DR. TOLSON: Okay.

MS. MEYERS-GLEN: Actually, I

apologize. This was asked and answered.

Well, no, it was asked and answered for

fishing and boating. How did Geosyntec

exercise professional judgment in setting

exposure duration for canoeing? We just

talked about fishing and --

DR. TOLSON: I'm pretty sure we

answered that, because we had the triangular

shaped figure up that had the one to five

hours, the two --

MS. MEYERS-GLEN: Right. But that's

off of data. Where did your professional

judgment come into play?

DR. TOLSON: It's not completely off

of data. We had data to sort of inform that,

but we had to make some professional judgment

decisions here.

MS. MEYERS-GLEN: And what were those?

DR. TOLSON: Well, we didn't go from

0152

zero hours. We truncated that distribution

so it went from one to five hours. You know,

selecting two hours as the median, it wasn't

directly out of the data. We just picked two

hours as a reasonable. It happened to fit

pretty nicely. So the mean of that fit the

EPA's exposure factor's handbook distribution

of data for people that recreate around lakes

and rivers.

MS. MEYERS-GLEN: But ultimately you

used your professional judgment to arrive at

that figure.

MR. ANDES: With data.

MS. MEYERS-GLEN: Excuse me. That's

not his testimony. Please allow the witness

to testify.

Is that ultimately how you

arrived with --

DR. TOLSON: With data. Sorry.

MS. MEYERS-GLEN: That's all. I have

no further questions at this time.

MS. WILLIAMS: Can I just ask one

follow-up?

HEARING OFFICER TIPSORD: Absolutely.

0153

You can ask two.

MS. WILLIAMS: No. I hope not. Do

you have a copy of Mr. Stuba's testimony?

DR. TOLSON: I do not. I don't think

I've seen that either.

MS. WILLIAMS: Do you have one that

you can show him, or do you want me to show

him?

MR. ANDES: I don't think I have that

handy.

MS. WILLIAMS: Mr. Stuba's testimony

is Exhibit 62, and I'm handing you a copy.

And I'd like you to take a look at the back

where he has charts.

DR. TOLSON: Okay.

MS. WILLIAMS: Where they list types

of recreational activity. Did you look at

those in developing your risk assessment, the

data from the district on recreation from the

boats that go out to --

DR. TOLSON: We looked at this and we

had some interviews with them, but we did not

rely on this for any numerical computations

for activities.

0154

MS. WILLIAMS: Do you understand where

jet skiing is logged on those logs as a

recreational activity?

DR. TOLSON: Don't see a jet skiing in

a column that's on the top of this. I don't

know whether they hadn't seen one and that's

the reason that they didn't start to log that

and put it on here or not. But we relied on

the UAA which was designed specifically to

evaluate recreational use. And we felt that

the strongest sort of data set to use to take

proportions of recreational users in each of

the modifications we were looking at.

MS. WILLIAMS: And obviously this is a

question I should have asked of Mr. Stuba, I

just didn't really realize it was an issue

until today. So if none of you know, then

that's fine. But what I would like to know

is he does say in his testimony that there

were six jet skiers observed?

MR. ANDES: If I can take a look.

MS. WILLIAMS: I would like to know

from the District, and if these witnesses

can't answer, we'll try to bring it up next

0155

week.

MR. ANDES: I'm sure they can't.

MS. WILLIAMS: Which category would

the six jet skiers have been logged under?

MR. ANDES: Skiing and tubing.

MS. WILLIAMS: So jet skiing was

considered a type of skiing and tubing?

MR. ANDES: Yes.

MS. WILLIAMS: Thank you. That's all

I have.

MS. MEYERS-GLEN: May I ask one

question that I forgot to ask?

HEARING OFFICER TIPSORD: Sure.

MS. MEYERS-GLEN: Thank you. Your

risk assessment -- I think this will be

pretty clear, but it doesn't account for the

highest areas of recreational use in the

waterway, correct?

DR. TOLSON: I did not say that.

MS. MEYERS-GLEN: Well, does your

study account for -- Does it take into

account where recreational use most commonly

occurs in setting risk?

DR. TOLSON: We may have -- we did not

0156

tease out use within any particular point

within the waterway. We assumed that risk --

we assumed that exposure could happen

anywhere along the waterway. We did take

data at specific points. Those points tended

to be in the dry weather, at least, close to

the District's outfalls. So they may have

actually biased high the potential influence

of the District's outfalls through the

waterway, pathogen concentrations within the

waterway.

MS. MEYERS-GLEN: Wasn't that averaged

out, though, with other data that was also

along the waterway farther downstream?

DR. TOLSON: Or actually within 10 to

15 both lengths upstream, but yes.

MS. MEYERS-GLEN: So what I'm

asking -- Withdraw the question. I'm done.

HEARING OFFICER TIPSORD: Anything

further? Dr. Gerba, Dr. Tolson,

Ms. Petropoulou, it has been a privilege and

an honor. Thank you very much. And I will

see all of us again on September 23, 9:00

a.m. here in this room where we will start

0157

with Dr. Divorich. Thank you very much.

We're adjourned.

(At which time the hearing was

continued to September 23,

2008, at 9:00 a.m.)

* * * * * *

0158

1 STATE OF ILLINOIS )

) SS.

2 COUNTY OF COOK )

I, LAURA MUKAHIRN, being a Certified

5 Shorthand Reporter doing business in the City of

6 Chicago, Illinois, County of Cook, certify that I

7 reported in shorthand the proceedings had at the

8 foregoing hearing of the above-entitled cause. And

9 I certify that the foregoing is a true and correct

10 transcript of all my shorthand notes so taken as

11 aforesaid and contains all the proceedings had at

12 the said meeting of the above-entitled cause.

___________________________

LAURA MUKAHIRN, CSR

CSR NO. 084-003592