IPCB

Additional

Comments,

January

16,

2013

Samuel

V.

Panno

7’’

These

comments

are provided

as

clarification

of my

testimony

at the

Illinois

Pollution

Control

Board

hearing

of

October

30, 2012

in

DeKaib,

IL

and

with

regard

to

testimony

by

Mr. Trainor

at

the IPCB

hearing

of

November

14,

2012

in

Elizabeth,

IL.

Contrary

to Mr.

Trainor’

s

statement

that

“all

groundwater

is

reduced”

and

therefore

no

bacteria

can

survive

in

it,

it has

been

my

experience

and the

experience

of

most

geochemists

who

have

sampled

shallow

groundwater

that

groundwater

in open

systems

(sand

and

gravel

and karst

aqiufers)

is

oxygen

enriched

and

typically

contains

abundant

bacteria

(both natural

and

human

related)

and

nitrate

(a

ion

that

is

rapidly

converted

to nitrogen

gas in

a reduced

groundwater

environment).

During

sampling

events

in southwestern

Illinois

involving

over

50

wells

drilled

into

karst

limestone

to depths

of

over

200

feet, and

15 karst

springs

in

southwestern

and

northwestern

Illinois,

oxygen

contents

of

the well

and

spring

waters

were

similar

to those

of

surface

water (i.e.,

between

5

and

10

mg/L dissolved

oxygen).

In this

area, we

found

that

all

of

the

springs

and

two thirds

of the

private

wells contained

enteric

bacteria

and

all contained

surface-borne

contaminants.

Using

the

species

of bacteria

as

an

indicator,

we concluded

that

the

sources

of

bacteria

were

both

livestock

and

human.

Recently,

I teamed

up with

Dr.

Walton

Kelly

(Illinois

State

Water

Survey),

Dr.

Wen-Tso

Liu

(Dept.

of Civil

and

Env.

Engineering,

University

of Illinois),

and

Ya

Zhang

(a

graduate

student

under

Dr. Liu)

and

conducted

research

in karst

areas

of

Illinois,

Missouri,

Kentucky

and Wisconsin

using

genetic

biomarkers.

The

biomarkers,

bacterial

indicators

and groundwater

chemistry

revealed

the

same mixture

of livestock

and

human

enteric

bacteria

present

in

the

karst

aquifers

of all

of

these

states.

Creviced

carbonate

bedrock

forming

karst aquifers

create

a class

of aquifers

referred

to

as

open

systems.

Groundwater

within

open

systems

is oxygenated

and

tends

to

remain

so.

In

areas

with

a

high

degree

of karstification,

it

is not uncommon

to

find

small

fish

swimming

within

bedrock

wells.

In sand

and gravel

deposits

near

streams,

amphipods

have

been

observed

living

within

the

groundwater

of

the

sand and

gravels

at depths

of

over

15 feet

(Tim

Young,

ISGS,

personal

communications).

All

require

oxygen

to survive.

Closed

systems

are those

aquifers

that

are

somewhat

isolated

from

surface

recharge

either

by

depth

or

by

low-permeability

layers

overlying

them

(e.g.,

shale).

Groundwater

in closed

systems

tends

to

be oxygen

poor and

progressively

become

more

chemically

reducing

with

greater

isolation

and/or

depth.

Mr. Trainor

suggested

that

characterization

using

dye tracing

and trenching

of sites

underlain

by

karst

aquifers

was

unnecessary

and

that these

aquifers

were

dominated

by

porous

media

flow.

Regarding

characterization

techniques

and

as I

stated in

my original

testimony,

it

is well

known

by

karst

hydrologists

that

dye tracing

and trenching

is

absolutely

essential

for

site

characterization

of flow

paths

and

flow rates

in

a

karst area;

karst

aquifers

are not

dominated

by

---

porous media flow, but by crevice and conduit flow. The

difference

is

that crevices and conduits

provide focused pathways for groundwater to travel very

quickly and in directions that may

be

counter

to what would be expeated in porous media flow. For this reason, groundwater

flow in

karst aquifers cinnot be characterized and modeled without

a thorough inspection of the

bedrock

(e.g.,

via excavations) and

dye

tracing (techniques

recommended by karst hydrologists).

Ms. Manning from the

Illinois

Department of Agriculture asked what the

cost to the “average

farmer” would be for determining the depth of soil on their property. An approximate

depth

of

soil or depth

to

bedrock would be available from the Illinois

State Geological Survey

(ISGS)

upon request. The information would

be

based on existing

drilling data and private well

data

available in

the

ISGS on-line

data base.

Finally,

recent

work

by

Dr.

George Roadcap

of

the Illinois State Water Survey showed

that

surface-borne

contaminants were entering sand

and

gravel

aquifers that lay beneath

50 to 60 feet

of clay-rich glacial till in northeastern Illinois (Dr. G. Roadcap, ISWS,

personal

communications). Currently, it is not clear how the contaminants

reached the protected aquifers,

but possible vectors include deep, continuous fractures in the till (macropores)

and/or abandoned

wells. Both are common in Illinois and constitute points of entry

to

underlying

aquifers that were

previously thought to be well-protected from surface-borne contaminants. This new

information

highlights the importance of

a

relatively thick soil zone overlying

karstified carbonate rock.

Instead of tens of inches thick, the soil should be tens

of feet thick in order to provide

some

protection to the underlying groundwater.