Alabama’s Water Quality
Assessment and Listing
Methodology
ADEM QA Workshop
February 13, 2006
Background….
• Section 305(b) of the Clean Water Act requires that
states report on the condition of their waters every
two years
• The report is due to EPA on April 1 of each even
numbered year
• The report describes the quality the state’s waters
relative to the state’s water quality standards
• The report is intended to inform Congress on the
progress being made to fulfill the mandate of the
Clean Water Act – “restore and maintain the
chemical, physical, and biological integrity of the
Nation’s waters.”
How? It Starts with Monitoring
• Monitoring data, primarily water quality
data from surface waters, provides the basis
for determining the status of water quality
• How clean is clean enough? Alabama’s
water quality standards (335-6-10 and 3356-11) are the yardstick we use to measure
the degree to which waters are clean enough
to support their designated uses
Water Quality Assessment….
• We need some instructions on how to use
the yardstick
• The assessment and listing methodology
describes the process of using measured
water quality data and biological
assessment information to determine when
waters are supporting their designated uses
The Early Years…
Listing Methodology????
• Prior to the 1998 303(d) list Alabama had no formal
assessment and listing methodology
• Impaired waters were defined based on information
contained in the State’s 305(b) Report – Appendix E
• The use support status was assigned based on an
unspecified and mysterious process know as the
“Mike Rief” formula (later know as the “Lynn Said”
method)
• In 1999 EPA added waters to Alabama’s 303(d) list
using the “EPA Said” method
The Early Assessment Model
(Model A)
• For the 1998 303(d) list ADEM developed an
assessment and listing methodology based loosely on
EPA’s 1997 Supplemental 305(b) guidance
• It included minimum data requirements, threshold
for number of exceedances of criterion, consideration
of biological data, and consideration of fish and
shellfish consumption advisories
• However, the “Lynn Said” method still played a
major role in the development of the list
Clearly, Something Better Was
Needed…..
For the 2002 List Cycle…
• EPA’s 305(b) / 303(d) guidance changed and
gave states the option to use an Integrated
Report (5-part list) to satisfy reporting
requirements of 305(b) and 303(d)
• Alabama did not select this option but chose
to submit both reports (305(b) and 303(d))
using the previous guidance and listing
methodology
For the 2004 List Cycle…
• EPA issued additional clarifying guidance
about the 5-part list and asked that states
use the new format, if possible
• Alabama adopted the new Integrated
Report format but continued to use the
previous listing methodology (303(d))
• By this point, something new was on the
horizon…..
In 2005….
• EPA issued additional guidance concerning
the content of the Integrated Report and the
listing methodology for the 2006 Cycle
• Alabama drafted a new assessment and
listing methodology to be used in
preparation of the 2006 Integrated Report
New and Improved….
• Alabama’s New Assessment and Listing
Methodology was written to:
– Provide EPA and the Public with a clear
understanding of how the state assesses
designated use support for its surface waters
– Ensure consistency in assessing waters
– Aid the state in planning future work and
resource needs
The 2010 Assessment and Listing
Methodology….
• Assesses a waterbody’s designated use support status
by considering:
– Chemical data
• Conventional pollutants - BOD, nutrients, solids
• Toxic pollutants – metals, pesticides, ammonia
– Physical data
• In situ parameters – pH, temperature, DO, turbidity
• Habitat characteristics for wadeable streams
– Biological data
• Aquatic communities – macros, fish, bacteria, algae, periphyton
Alabama’s Categories….
• Category 1 – All uses fully supported
– Requires a rigorous data analysis of a dataset
that satisfies the minimum data requirement
• Category 2 – Insufficient data to determine
if all uses are fully supported
– Prioritizes future sampling (2a, 2b)
• Category 3 – We know nothing about this
water (other than some generalizations
about its watershed)
– Some of these waters may be included in basin
rotation monitoring plan during each cycle
Alabama’s Categories….
• Category 4 – Impaired waters that do not
need a TMDL
– Track TMDL development (4a)
– Track Implementation of “other control
measures” (4b, 4c)
• Category 5 – Impaired waters that do need
a TMDL
– Basis for TMDL development program
– Priority for future monitoring (if needed)
Methodology Design – What Must it
Do?
• The assessment and listing methodology must do the
following:
– Populate the 5 categories of waters described in Alabama’s
5-part list and outlined in the EPA guidance
– Provide a scientifically defensible process for determining
use impairment (303(d) listing/delisting)
– Recognize the different levels of aquatic life use established
in Alabama’s water quality standards
• OAW ------------------------------------------------------ A&I
– Provide the public with a clear understanding of what is
required to determine designated use support or nonsupport
How Does it Work?
• Data and information are put through a series
of filters that are specific to the water’s
designated use
• The first filter is the minimum data filter
– Waters not passing the minimum data filter go to
Category 2 or Category 3 (if no data)
– Waters passing the minimum data filter go to the
second filter
How Does it Work?
• The second filter compares the available
data to the water quality criteria for the
designated use
– If the data indicate “compliance” with the
criteria, the water is placed in Category 1
– If the data indicate “noncompliance” with the
criteria, the water is placed in Category 5
How Does it Work?
• The threshold for “noncompliance” is
specific to the particular use and/or
waterbody type
– Sensitive waters (OAW) have a lower threshold
than Fish and Wildlife waters
– Wadeable streams can have a different
threshold than nonwadeable streams
For Example:
Outstanding Alabama
Water
Public Water Supply
Swimming
Shellfish Harvesting
Fish & Wildlife
Limited Warmwater
Fishery
Agricultural & Industrial
Water Supply
OAW Use Support
Assessment
PWS Use Support
Assessment
S Use Support
Assessment
SH Use Support
Assessment
F&W Use Support
Assessment
LWF Use Support
Assessment
A&I Use Support
Assessment
Category I
Category I
Category I
Category I
Category I
Category I
Category I
Category II
Category II
Category II
Category II
Category II
Category II
Category II
Category
IIa
Category
IIa
Category
IIa
Category
IIa
Category
IIa
Category
IIa
Category
IIa
Category
IIb
Category
IIb
Category
IIb
Category
IIb
Category
IIb
Category
IIb
Category
IIb
Category III
Category III
Category III
Category III
Category III
Category III
Category III
Category V
Category V
Category V
Category V
Category V
Category V
Category V
Category
IVb
pollution
Category
IVc
other
program
pollution
Category
IVc
Category
IVa
approved
TMDL
Category
IVb
other
program
pollution
Category
IVc
Category
IVa
approved
TMDL
Category
IVb
other
program
pollution
Category
IVc
Category
IVa
approved
TMDL
Category
IVb
other
program
pollution
Category
IVc
Category
IVa
approved
TMDL
Category
IVb
other
program
pollution
Category
IVc
other
program
Category
IVb
Category
IVa
approved
TMDL
Category
IVa
approved
TMDL
pollution
Category
IVc
other
program
Category
IVb
approved
TMDL
Category
IVa
What Does It Mean to the Monitoring
Program?
• The methodology establishes new minimum data
requirements for each of Alabama’s seven
designated uses
• The goal of the assessment process is to place each
waterbody in Alabama into one of the five
categories mentioned earlier
• The assessment period is 6 years long and
minimum data requirements can be met using
data from several years and from several sources
if the data are “comparable”
Minimum Data Requirements
• Minimum data requirements are dictated
by use classification and waterbody type
– OAW:
•
•
•
•
Wadeable stream
Non-wadeable stream / river
Reservoir
Estuary or coastal water
• A waterbody must satisfy the minimum
data requirements to be placed in Category
1 or 5 with only a few exceptions
Minimum Data Requirements…
• In general, wadeable streams will require:
– 1 or more biological assessments including habitat +
3 conventional parameter measurements + 5
bacteriological measurements
• Biological assessment could include:
– 1 Level IV Intensive Wadeable Multi-habitat Bioassessment
(WMB-I)
– 2 Level III Wadeable Multi-habitat Bioassessments (WMB-EPT)
– 1 WMB-EPT + 1 Fish IBI (Cahaba / Warrior Basins)
– Or 8 or more conventional parameter
measurements + 10 bacteriological + 5
pesticide/herbicide + 5 inorganic (metals)
Minimum Data Requirements…
• In general, non-wadeable streams will
require:
– 8 or more conventional parameter
measurements + 10 bacteriological + 5
pesticide/herbicide + 5 inorganic (metals)
Minimum Data Requirements…
• In general, reservoirs will require:
– 8 conventional parameter measurements + 3
bacteriological samples + 1 fish tissue analysis +
7 chlorophyll a samples (where a criterion is in
place)
Minimum Data Requirements…
• In general, coastal waters will require:
– 8 or more conventional parameter
measurements + 10 bacteriological + 1 fish
tissue analysis
– OR 8 or more conventional parameter
measurements + 10 bacteriological + 5 pesticide
/ herbicide + 5 inorganic (metals)
Data Quality…
• Data collected by third parties and
submitted to the Department must be
collected and analyzed consistent with the
procedures specified in the Department’s
SOP manuals.
• In most cases, this means that a study plan
with specific methods and procedures
should accompany data submitted to the
Department for consideration.
So, once we have the data…
• A review of available data will result in the
placement of a waterbody in either
– Category 1 – met minimum data requirement and fully
supports uses
– Category 2A – did not meet minimum data requirement
but available data indicates possible impairment –
collect more data.
– Category 2B – did not meet minimum data requirement
but available data does not indicate impairment –
collect more data later
– Category 5 – met minimum data requirement and an
impairment is indicated – 303(d) List
So, what goes in Category 5?
• Each designated use has a slightly different
impairment threshold
• In general, wadeable streams will be placed
in Category 5 when:
– WMB-I is poor or both WMB-EPT are poor due to
anthropogenic causes
– More than two exceedances of a toxic pollutant criterion
– An conventional parameter exceeds its criterion in more
than 10% of the samples based on the binomial
distribution
– A Fish Consumption Advisory is issued by the ADPH
Here’s an Example:
• A water quality study is conducted on a wadeable
stream in the Choctawhatchee River Basin
• A WMB-I biological assessment is conducted along
with several habitat assessments. The habitat
assessment rates the site as “Poor” and the
biological assessment indicates a “Poor” macro
community. Water quality data looked normal.
• So what’s the problem? Why the “Poor” biology?
Example….
• Specific comments recorded by the field
biologist describe the site as “Channelized
heavily. Soft sand bottom heavily covered in
silt. No Root Bank. Sand, CPOM, Log Wash
samples consist of all Chironomidae. No
EPT taxa found. This stream is in pathetic
shape!”
• Result – Category 5 for siltation
Determining Use Support: the “10%
Rule”
• Probably the most misunderstood part of
the methodology
• The methodology uses a binomial
distribution to estimate the number of
exceedances of a criterion in a given
number of samples needed to say with a
known confidence that the exceedance rate
is greater than 10%
• Used for conventional parameters
The “10% Rule” for Listing:
Here’s How it Looks
Table 2
Minimum Number of Samples Exceeding the Numeric
Criterion Necessary for Listing*
Sample Size
Number of Exceedances
Sample Size
Number of Exceedances
8 thru 11
12 thru 18
19 thru 25
26 thru 32
33 thru 40
41 thru 47
48 thru 55
56 thru 63
64 thru 71
72 thru 79
80 thru 88
89 thru 96
2
3
4
5
6
7
8
9
10
11
12
13
97 thru 104
105 thru 113
114 thru 121
122 thru 130
131 thru 138
139 thru 147
148 thru 156
157 thru 164
165 thru 173
174 thru 182
183 thru 191
192 thru 199
14
15
16
17
18
19
20
21
22
23
24
25
Using the “10% Rule” for Delisting
• Not the same thing as listing
• Uses a binomial distribution to estimate the
number of exceedances of a criterion in a
given number of samples needed to say with
a known confidence that the exceedance
rate is less than 10%
The “10% Rule” for Delisting:
Here’s How it Looks
Table 3
Maximum Number of Samples Exceeding the Numeric
Criterion Necessary for Delisting*
Sample Size
Number of Exceedances
Sample Size
Number of Exceedances
8 thru 21
22 thru 37
38 thru 51
52 thru 64
65 thru 77
78 thru 90
91 thru 103
0
1
2
3
4
5
6
104 thru 115
116 thru 127
128 thru 139
140 thru 151
152 thru 163
164 thru 174
175 thru 186
7
8
9
10
11
12
13
THE
END!