Office
of
Water
Federal
Advisory
Committee
on
Detection
and
Quantitation
Approaches
and
Uses
in
EPA's
Clean
Water
Act
Programs
Common
Base
of
Information
June
22,
2005
Office
of
Water
Presentation
Overview
 
EPA
and
Clean
Water
Act
(
CWA)
mandates
 
Statutory
authority
for
analytical
methods
in
EPA's
CWA
programs
 
History
of
detection
and
quantitation
 
Chronological
 
Emphasis
on
history
in
EPA's
CWA
programs
 
Where
we
are
today
 
Note:
information
is
intended
for
those
not
intimately
familiar
with
detection
and
quantitation,
and
may
be
largely
repetitive
for
those
involved
over
the
years
Office
of
Water
EPA
and
Clean
Water
Act
Mandates
 
EPA's
mandate
is
to
"
protect
human
health
and
the
environment"

 
CWA's
mandate
is
to
"
restore
and
maintain
the
chemical,

physical,
and
biological
integrity
of
the
Nation's
waters"

 
Detection
and
quantitation
limits
must
support
these
mandates
 
Examples
 
Measurements
need
to
be
made
at
ambient
water
quality
criteria
levels
to
assure
protection
of
aquatic
life
 
Measurements
need
to
be
made
to
support
waste
load
allocations
for
total
maximum
daily
loads
(
TMDLs)
Office
of
Water
Congressional
Authority
for
Analytical
Methods
 
Clean
Water
Act
(
CWA)
Sections
301(
a),
304(
h),
and
501(
a)
provide
the
statutory
authority
for
test
procedures
(
analytical
methods)

 
Section
301(
a)
prohibits
discharge
of
a
pollutant
without
a
permit
 
Section
304(
h)
requires
EPA
to
promulgate
guidelines
establishing
test
procedures
for
the
analysis
of
pollutants
 
Section
501(
a)
authorizes
the
EPA
Administrator
to
prescribe
regulations
necessary
to
carry
out
CWA
functions
 
CWA
methods
are
promulgated
at
Title
40,
parts
136
and
405
 
599,
of
the
Code
of
Federal
Regulations
(
CFR),
written
as,
e.
g.,
40
CFR
part
136
Office
of
Water
Characteristics
of
an
Analytical
Method
 
In
environmental
analytical
chemistry,
a
method
is
a
series
of
steps
(
a
procedure)
that
leads
to
a
result
(
concentration
or
amount)
for
an
analyte
in
a
sample
 
Method
performance
characteristics
include
 
Precision
 
Recovery
 
Specificity
 
Detection
and
quantitation
limit
(
sometimes
termed
"
sensitivity")

 
The
focus
of
this
FACA
is
on
how
to
establish,
evaluate,

and
apply
detection
and
quantitation
limits
Office
of
Water
Detection/
quantitation
Limit
History
 
Seminal
work
on
detection
and
quantitation
is
by
Lloyd
Currie,
recently
retired
from
NIST
 
Published
in
Analytical
Chemistry
in
1968
(
40,
p586)

 
Introduced
terms
of
 
"
critical
level"
(
LC),
"
critical
value"
(
CRV);
the
"
detection
decision";
sometimes
"
detection
limit"

 
"
minimum
detectable
value"
(
MDV),
"
detection
limit"
(
LD)

 
"
determination
limit",
"
minimum
quantifiable
value"
(
MQV);

limit
of
quantitation"
(
LOQ);
commonly
"
quantitation
limit"
(
LQ)

 
Currie's
work
forms
the
basis
the
ISO/
IUPAC
nomenclature
and
standards,
and
nearly
all
other
approaches
Office
of
Water
Detection/
quantitation
History
 
ML
 
On
December
3,
1979,
EPA
proposed
the
600­
Series
organic
methods
(
44
FR
69463)

 
GC/
MS
Methods
624
and
625
contained
a
"
limit
of
detection"
for
each
compound
 
In
Method
624,
the
LOD
was
defined
as
defined
as
the
"
minimum
level
at
which
entire
system
must
recognizable
mass
spectra
and
acceptable
calibration
points"

 
In
Method
625,
the
LOD
was
defined
as
the
"
minimum
level
at
which
the
analytical
system
must
give
mass
spectral
confirmation."

 
The
LOD
in
Methods
624
and
625
 
Were
estimates
of
the
lowest
level
that
could
be
measured
and
the
basis
for
the
minimum
level
of
quantitation
(
ML)
Office
of
Water
Detection/
quantitation
Limit
­
MDL
 
Method
detection
limit
(
MDL)
was
first
published
in
a
paper
by
John
Glaser
and
others
at
EPA's
laboratory
in
Cincinnati
in
1981
in
Environmental
Science
and
Technology
(
15,
p1426)

 
MDL
based
on
Currie's
work
 
Employs
low­
level
spikes
rather
than
backgrounds
 
Uses
Student's
t­
test
to
allow
for
varying
number
of
replicates
 
Has
remained
largely
unchanged
since
publication
Office
of
Water
Detection/
quantitation
­
ACS
 
In
1980
and
1983,
the
American
Chemical
Society's
(
ACS's)
Committee
on
Environmental
Improvement
adopted
an
approach
similar
to
Currie's
 
"
Limit
of
detection"
(
LOD)
nearly
identical
to
Currie's
"
critical
value"
(
LC)
and
EPA's
MDL
 
"
Limit
of
quantitation"
nearly
the
same
as
Currie's
"
limit
of
quantitation"
(
LQ)
Office
of
Water
MDL
and
ML
Promulgation
 
On
October
26,
1984
(
49
FR
43234),
EPA
promulgated:

 
The
600­
and
1600­
Series
organic
methods
at
40
CFR
136,

appendix
A
 
The
600­
Series
methods
contained
MDLs
as
detection
limits
 
Methods
1624
and
1625
contained
MLs
as
detection
limits
 
The
MDL
procedure
at
40
CFR
136,
appendix
B
 
Method
200.7
for
metals
by
ICP/
MS
at
40
CFR
136,
appendix
C
 
Method
200.7
contained
MDLs
as
detection
limits
Office
of
Water
VEPCO
Suit
and
Settlement
 
In
early
1985,
members
of
the
power
industry
brought
suit
against
EPA
 
The
suit
claimed,
among
other
things,
that
the
MDL
procedure
in
appendix
B
should
be
applicable
to
the
organic
methods
in
appendix
A
only
 
On
July
12,
1985,
EPA
signed
a
settlement
agreeing
to
industry's
condition
 
The
settlement
did
not
preclude
future
use
of
the
MDL
by
EPA
or
the
right
of
the
litigants
to
bring
suit
over
future
use
Office
of
Water
Use
of
ML
in
OCPSF
Rule
 
On
November
5,
1987
(
52
FR
42522),
EPA
published
a
final
rule
for
the
Organic
Chemicals,
Plastics,
and
Synthetic
Fibers
(
OCPSF)
industrial
category
 
The
rule
was
the
first
use
of
the
ML
as
an
effluent
limit
and
data
censoring
point
 
Data
below
the
MLs
listed
in
Methods
1624
and
1625
were
not
considered
in
calculating
effluent
limits
 
No
limit
was
set
below
10
µ
g/
L
 
Significant
because
MDLs
were
not
used
for
effluent
limits
or
regulatory
compliance;
instead,
MLs
were
used
 
Nearly
all
subsequent
effluent
guidelines
were
censored
to
the
ML
Office
of
Water
WQBEL
Guidance
 
In
1994,
EPA
published
draft
"
National
Guidance
for
the
Permitting,
Monitoring,
and
Enforcement
of
Water
Quality­
based
Effluent
Limitations
Set
Below
Analytical
Detection/
Quantitation
Levels"
(
WQBEL
Guidance)

 
Guidance
suggested
use
of
the
ML
as
a
compliance
evaluation
threshold
when
the
ambient
water
quality
criterion
was
below
the
detection
limit
of
the
most
sensitive
analytical
method
 
Opposition
 
Industry
­
ML
too
low
 
States
­
ML
not
as
protective
as
the
MDL.

 
EPA
did
not
finalize
WQBEL
Guidance,
but
it
precipitated
further
discussions
of
detection
and
quantitation
limits
Office
of
Water
Refinement
of
ML
 
In
support
of
the
WQBEL
Guidance,
EPA
refined
the
ML
to
be
consistent
with
the
ISO/
IUPAC
LOQ
(
at
the
time)

and
the
ACS
LOD
 
ML
=
10
times
the
standard
deviation
of
7
replicates
 
ML
=
3.18
times
the
MDL
 
Directed
at
10%
RSD,
although
10%
RSD
may
not
be
achievable
for
some
analytes
in
some
methods
Office
of
Water
Alternate
Minimum
Level
(
AML)

 
In
1995,
in
response
to
the
WQBEL
Guidance,
the
Inter­

Industry
Analytical
Group
(
IIAG)
advanced
the
"
alternate
minimum
level"
(
AML)

 
AML
=
10
times
the
interlaboratory
standard
deviation,
adjusted
to
the
true
concentration
and
a
95
%
prediction
limit
 
Standard
deviation
modeled
linearly
as
a
function
of
concentration
 
AML
led
to
modeling
standard
deviation
vs
concentration
Office
of
Water
Rocke
and
Lorenzato
Two­
component
Model
 
In
1995,
David
Rocke
and
Stefan
Lorenzato
published
a
paper
(
Technometrics
37
p176)
giving
details
of
a
twocomponent
model
of
variability
(
as
standard
deviation)
vs
concentration
 
Region
in
which
standard
deviation
remains
constant
with
increasing
concentration
 
Region
of
Currie's
critical
value
(
LC)
and
EPA's
MDL
 
Region
in
which
standard
deviation
increases
proportional
to
concentration
 
Region
of
quantitation
 
Region
between
constant
and
proportional
standard
deviation
 
Transition
region
Office
of
Water
ASTM
IDE
and
IQE
 
In
the
mid­
to
late­
1990s,
Robert
Gibbons,
David
Coleman,
Nancy
Grams,
and
others
worked
through
IIAG
and
within
ASTM
Committee
D19
to
develop
the
"
interlaboratory
detection
estimate"
(
IDE)
and
"
interlaboratory
quantitation
estimate"
(
IQE)

 
IDE
and
IQE
used
a
model
of
standard
deviation
or
relative
standard
deviation
(
RSD)
as
a
function
of
concentration
as
the
basis
for
establishing
detection
and
quantitation
estimates
Office
of
Water
EPA
Method
1631
for
Mercury
 
On
June
8,
1999
(
64
FR
30417),
EPA
promulgated
Revision
B
to
EPA
Method
1631for
determination
of
mercury
by
purge­
and­
trap
and
atomic
fluorescence
 
MDL
established
at
0.2
ng/
L
 
ML
established
at
0.5
ng/
L
 
The
Alliance
of
Automobile
Manufacturers,
Inc.
and
others
brought
suit
over,
among
other
things,
the
detection
and
quantitation
limits
in
EPA
Method
1631
and
how
they
were
developed
Office
of
Water
Settlement
Agreement
 
In
Clause
6
of
a
Settlement
Agreement
signed
October
19,
2000,
EPA
agreed
to:

 
Re­
assess
procedures
for
determining
detection
and
quantitation
limits
 
Peer
review
the
re­
assessment
 
Provide
opportunity
for
comment
on
the
re­
assessment
 
Publish
a
notice
and
invite
comment
on
the
re­
assessment
by
February
28,
2003
 
Publish
a
notice
of
final
action
on
the
re­
assessment
by
September
30,
2004
Office
of
Water
Re­
assessment
Study
Plan
Peer
Review
 
In
2001,
EPA
developed
a
Study
Plan
for
the
reassessment
 
Although
not
required
by
the
Settlement
Agreement,
EPA:

 
Submitted
the
Study
Plan
to
peer
review
and
the
litigants
in
December
2001
 
Conducted
the
peer
review
in
accordance
with
the
EPA
Science
Policy
Council's
Peer­
Review
Handbook
 
Revised
the
Study
Plan
based
on
comments
received
from
the
peer
review
and
the
litigants
 
EPA
also
conducted
a
literature
search
on
detection
and
quantitation
to
support
the
re­
assessment
Office
of
Water
Study
Plan
for
the
Re­
assessment
 
The
re­
assessment
Study
Plan:

 
Described
roles
and
responsibilities
for
implementing
the
Plan
 
Provided
a
background
discussion
of
detection
and
quantitation
limit
concepts
 
Outlined
a
series
of
11
steps
to
the
re­
assessment.
Examples:

 
Develop
list
of
detection
and
quantitation
concepts
to
be
evaluated;
e.
g.,
ISO/
IUPAC
(
Currie)
LC,
LD,
LQ;
ASTM
IDE
and
IQE;
ACS
LOD
and
LOQ
 
Develop
a
list
of
criteria
against
which
the
concepts
would
be
evaluated
 
Evaluate
the
concepts
 
Peer
review
the
evaluation/
re­
assessment
Office
of
Water
Evaluation
of
Concepts
 
Evaluation
criteria
for
detection
and
quantitation
 
The
concept
must
be
scientifically
valid
 
It
can
and
has
been
tested
 
It
has
been
subjected
to
peer
review
and
publication
 
It
is
supported
by
a
well­
defined
procedure
 
It
has
been
accepted
by
the
scientific
community
 
The
error
rate
is
known
or
can
be
estimated
 
The
concept
must
include
routine
variability
 
The
concept
must
be
applicable
in
a
single
laboratory
 
The
detection
limit
concept
should
identify
the
concentration
at
which
there
is
99%
confidence
that
the
analyte
is
present
Office
of
Water
Evaluation
of
Concepts
(
cont'd)

 
Evaluation
criteria
for
detection
and
quantitation
(
cont'd)

 
The
quantitation
limit
should
identify
the
concentration
at
which
the
reliability
of
the
measurement
is
consistent
with
the
capabilities
of
a
method
practiced
by
an
experienced
staff
in
a
well­
operated
laboratory
 
Detection
and
quantitation
limits
must
be
applicable
to
the
variety
of
decisions
made
under
CWA,
and
should
support
State
and
local
obligations
to
implement
measurement
requirements
at
least
as
stringent
as
those
set
by
the
Federal
Government
Office
of
Water
Datasets
Used
in
the
Evaluation
 
EPA
evaluated
each
concept
using
datasets
developed
by
EPA
or
submitted
to
EPA
 
ICP/
MS
 
9
metals
at
12
concentrations
from
10
 
25,000
ng/
L
 
Multi­
technique
(
Episode
6000)
study
 
11
analytes/
techniques;
e.
g.,
TSS,
ammonia,
phosphorus;

organics
by
GC
and
GC/
MS;
metals
by
GFAA,
ICP/
OES,
and
ICP/
MS
 
7
replicates
at
16
concentrations,
from
0.1
 
100x
the
MDL
 
American
Automobile
Manufacturer
Association's
study
of
12
metals
by
ICP/
MS
and
mercury
by
CVAA
 
Method
1631
(
mercury)
interlaboratory
method
validation
study
Office
of
Water
Evaluation
of
Datasets
 
EPA
calculated
detection
and
quantitation
limits
using
the
various
concepts
 
EPA
MDL
and
ML;
ACS
LOD
and
LOQ;
ISO/
IUPAC
LC,
LD,
and
LQ;
ASTM
IDE
and
IQE
 
Two
concepts
were
combined
because
their
implementation
is
identical
 
EPA
MDL
and
ACS
LOD
@
3x
the
standard
deviation
 
EPA
ML
and
ACS
LOQ
@
10x
the
standard
deviation
 
Comparisons
of
results
published
in
tables
in
Appendix
C
to
the
technical
support
document
(
TSD)
Office
of
Water
Technical
Support
Document
 
Results
of
EPA's
evaluation
of
detection
and
quantitation
limits
were
published
in
a
"
technical
support
document"

(
TSD)

 
TSD
was
subjected
to
peer
review
and
submitted
to
litigants
 
TSD
was
revised
based
on
comments
received
Office
of
Water
Federal
Register
Proposal
 
On
March
12,
2003
(
48
FR
11770),
EPA
published
a
proposal
in
the
Federal
Register.
The
proposal:

 
Met
requirements
in
Clause
6.
a.
of
the
Settlement
Agreement
 
Announced
the
availability
of
the
re­
assessment,
peer
review,

and
TSD
 
Proposed
changes
to
the
MDL
procedure
based
on
the
reassessment
and
comments
received
 
Proposed
codification
of
the
ML
procedure
at
part
136
 
Invited
comments
on
the
re­
assessment
and
proposal
 
Based
on
requests,
EPA
extended
(
re­
opened)
the
comment
period
on
the
proposal
to
August
13,
2003
Office
of
Water
Comments
on
EPA's
Proposal
 
Some
comments
were
supportive
of
EPA's
reassessment
and
proposal,
but
many
were
strongly
critical
 
Some
commenters
provided
suggestions
for
improving
EPA's
MDL
and
ML
procedures;
others
provided
suggestions
for
alternative
procedures
 
Based
on
comments
received,
EPA
revised
the
reassessment
and
TSD
Office
of
Water
Final
Re­
assessment
 
On
November
8,
2004
(
69
FR
64704),
EPA
published
a
"
Revised
Assessment
of
Detection
and
Quantitation
Approaches"

 
The
revised
assessment
met
requirements
in
Clause
6.
f
of
the
Settlement
Agreement
 
The
revised
assessment
was
supported
by
a
"
revised
assessment
document"
(
RAD),
successor
to
the
TSD
Office
of
Water
Withdrawal
of
Proposal
 
Also
on
November
8,
2004
(
69
FR
64707),
EPA
withdrew
the
proposed
changes
to
the
MDL
and
codification
of
the
ML
 
FR
notice
announced
EPA
plans
to
work
with
stakeholders
to
address
concerns
about
use
of
detection
and
quantitation
limits
in
EPA's
CWA
programs
 
The
withdrawal
was
preceded
by
a
September
15,
2004
(
69
FR
55547)
notice
of
EPA's
intent
to
perform
an
assessment
of
the
detection
and
quantitation
situation
 
The
FR
withdrawal
and
September
15
notice
left
the
status
of
the
MDL
and
ML
unchanged
Office
of
Water
FACA
Formation
 
On
December
29,
2004
(
69
FR
77972),
EPA
announced
a
half­
day
public
meeting
to
be
held
January
26,
2005
to
report
findings
in
the
"
Situation
Assessment
Report
on
Detection
and
Quantitation
Approaches
and
Uses
in
[
EPA's]
Clean
Water
Act
Programs"
and
formation
of
today's
Federal
Advisory
Committee
 
On
May
24,
2005
(
70
FR
29743),
EPA
announced
today's
first
meeting
of
the
"
Federal
Advisory
Committee
to
Examine
Detection
and
Quantitation
Approaches
in
[
EPA's]
Clean
Water
Act
Programs"
Office
of
Water
Where
we
are
today
 
Lots
of
background
information
 
This
presentation
 
EPA's
FACA
and
detection/
quantitation
web
sites
 
Water
Docket
for
the
re­
assessment
and
final
assessment
 
Includes
TSD
and
RAD
 
Notwithstanding
the
background
information,
EPA
wants
the
FAC
to
operate
from
a
clean
slate
to
arrive
at
scientifically
sound
concepts
and
implementations
of
detection
and
quantitation
 
No
prejudices;
no
intransigencies;
no
worries
Office
of
Water
Additional
Information
For
additional
information
contact:

Richard
A.
Reding,
Chief
Statistics
and
Analytical
Support
Branch
Engineering
and
Analysis
Division
(
4303T)

Office
of
Science
and
Technology,
Office
of
Water
U.
S.
Environmental
Protection
Agency,
Ariel
Rios
Building
1200
Pennsylvania
Ave,
NW
Washington,
DC
20460
Voicemail:
202­
566­
2237
E­
mail:
reding.
richard@
epa.
gov
