National
Water
Quality
Inventory:
2000
Report
The
National
Water
Quality
Inventory
is
prepared
under
Section
305(
b)
of
the
Clean
Water
Act.
Section
305(
b)
requires
that
states,
territories,
and
jurisdictions
assess
their
water
quality
biennially
and
report
those
findings
to
the
EPA.
EPA
then
summarizes
these
findings
in
a
national
water
quality
inventory.

Purpose:
The
inventory
provides
a
summary
of
the
water
quality
status
of
the
nation's
waters,
sources
of
water
quality
problems,
and
recommendations
on
management
actions
necessary
to
protect
and
restore
them.

Chemicals:
The
report
lists
the
major
pollutants
and
other
causes
of
water
quality
problems
as:
pathogens,
nutrients,
metals,
siltation,
oxygen­
depleting
substances,
total
dissolved
solids,
habitat
alterations,
pesticides,
flow
alterations,
filling
and
draining,
turbidity,
oil
and
grease,
priority
toxic
organic
chemicals,
PCBs,
thermal
modifications,
and
excess
algal
growth.

Sample
Locations:
The
inventory
summarizes
water
quality
reports
submitted
by
all
50
states,
the
District
of
Columbia,
and
5
territories;
4
interstate
commissions;
and
5
Indian
tribes.
Separate
analyses
are
done
for
rivers
and
streams;
lakes
and
ponds;
estuaries;
ocean
shorelines;
Great
Lakes
shoreline;
coral
reefs;
wetlands;
and
groundwater.

Sample
Design:

The
table
below
shows
the
amount
of
each
type
of
water
body
that
was
assessed.

AMOUNT
ASSESSED
FOR
EACH
TYPE
OF
WATER
BODY
Water
Body
Type
Total
Size
Amount
Assessed
Rivers
(
miles)
3,692,830
699,946
(
19%)

Lakes
(
acres)
40,603,893
17,339,080
(
43%)

Estuaries
(
sq.
miles)
87,369
31,072
(
36%)

Ocean
Shoreline
(
miles)
22,618
(
excluding
Alaska)
3,221
(
14%)

Wetlands
(
acres)
105,500,000
8,282,133
(
8%)
The
assessments
are
based
on
both
monitored
data
and
on
qualitative
information.
The
table
below
shows
the
type
of
data,
actual
monitoring
or
qualitative
information,
that
was
used
for
the
assessments.
States
did
not
always
specify
what
type
of
information
was
used
,
therefore,
the
numbers
do
not
sum
to
100%,.

TYPE
OF
DATA
USED
IN
ASSESSMENTS
Water
Body
Type
%
Assessed
by
Monitoring
%
Assessed
Qualitatively
Rivers
(
miles)
46%
36%
(
also
includes
monitoring
data
>
5
years
old)

Lakes
(
acres)
68%
28%

Estuaries
(
sq.
miles)
51%
32%

Ocean
Shoreline
(
miles)
34%
59%

Wetlands
Information
not
provided.

Time
Period
Covered:
Reports
are
produced
every
two
years.
The
most
current
report
is
for
2000
and
the
previous
report
was
for
1998.

Evaluation
Method:
To
assess
water
quality,
states
and
other
jurisdictions
compare
their
monitoring
results
to
the
water
quality
standards
they
have
set
for
their
waters.
Water
quality
standards
consist
of
three
elements:
the
designated
uses
assigned
to
waters
(
such
as
drinking,
swimming,
or
fishing),
criteria
to
protect
those
uses
(
such
as
chemical­
specific
thresholds
that
should
not
be
exceeded),
and
an
anti­
degradation
policy
intended
to
keep
waters
that
do
meet
standards
from
deteriorating
from
their
current
condition.

Results:
In
total,
about
33%
of
U.
S.
waters
were
assessed.
Leading
causes
of
impairment
in
assessed
waters
include
bacteria,
nutrients,
metals
(
primarily
mercury),
and
siltation.
Mercury
is
the
cause
of
impairments
mainly
due
to
the
widespread
detection
of
mercury
in
fish
tissue
samples.
It
is
important
to
note
that
10
states
did
not
include
the
effects
of
statewide
fish
consumption
advisories
for
mercury
when
calculating
their
summary
use
support
statistics
in
rivers
and
streams
and
11did
not
for
lakes.
One
state,
New
York,
excluded
the
effect
of
a
statewide
PCB/
chlordane/
mirex/
DDT
fish
consumption
advisory
for
rivers,
streams,
and
lakes.
If
these
statewide
advisories
had
been
included,
all
of
these
states
rivers,
streams
and
lakes
would
have
received
an
impaired
rating.

Runoff
from
agricultural
lands,
municipal
point
sources
(
sewage
treatment
plants),
and
hydrologic
modifications
(
such
as
channelization,
flow
regulation,
and
dredging)
are
the
primary
sources
of
impairment.
It
is
important
to
note
that,
for
many
waters,
states
and
other
jurisdictions
classify
the
causes
and
sources
as
unknown.
The
overall
results
showing
the
major
pollutants/
stressors
are
presented
in
the
below.
The
percentages
shown
are
the
percent
of
impaired
waters
with
the
particular
pollutant/
stressor
reported
as
the
cause
of
the
impairment.
[
Blank
spaces
indicate
that
the
particular
pollutant/
stressor
was
not
listed
in
the
summary
information
on
major
pollutants
for
that
type
of
water
body.]

POLLUTANTS/
STRESSORS
Pollutant/
Stressor
Rivers/
Streams
(
Rank/
%
Impaired)
Lakes/
Ponds
(
Rank/
%
Impaired)
Estuaries
(
Rank/
%
Impaired)
Ocean
Shoreline
Waters
(
Rank/
%
Impaired)
Wetlands
(
Rank/
#
of
States)

Pathogens
1/
35%
4/
30%
1/
88%

Nutrients
5/
20%
1/
50%
7/
10%
3/(
4
States)
Metals
7/
15%
2/
42%
1/
52%
6/
11%
6/(
3
States)
Siltation
2/
31%
3/
21%
1/(
6
States)
Oxygen­
Depleting
Substances
4/
21%
5/
15%
3/
34%
2/
24%
Total
Dissolved
Solids
4/
19%
7/
16%
4/
12%
Habitat
Alterations
3/
22%
5/(
3
States)
Pesticides
7/
8%
2/
38%
Flow
Alterations
8/
9%
2/(
5
States)
Filling
and
Draining
4/(
3
States)
Turbidity
3/
12%
Oil
and
Grease
5/
11%
Priority
Toxic
Organic
Chemicals
5/
23%
PCBs
6/
17%
Thermal
Modifications
6/
17%
Excess
Algal
Growth
6/
12%
The
overall
results
showing
the
major
sources
of
the
pollutants/
stressors
are
presented
in
the
below.
The
percentages
shown
are
the
percent
of
impaired
waters
that
reported
that
source
as
the
source
of
the
impairment.
[
Blank
spaces
indicate
that
the
particular
source
was
not
listed
in
the
summary
information
on
major
sources
of
pollutants/
stressors
for
that
water
body.]

SOURCES
Sources
Rivers/
Streams
(
Rank/
%
Impaired)
Lakes/
Ponds
(
Rank/
%
Impaired)
Estuaries
(
Rank/
%
Impaired)
Ocean
Shoreline
Waters
(
Rank/
%
Impaired)
Wetlands
(
Rank/
#
of
States)

Agriculture
1/
48%
1/
41%
5/
18%
1/(
4
States)

Municipal
Point
Source
6/
10%
6/
12%
1/
37%
5/
20%
Hydrologic
Modification
2/
20%
2/
18%
6/
14%
3/(
2
States)
Urban
Runoff/
Storm
Sewers
4/
13%
3/
18%
2/
32%
1/
56%
4/
(
2
States)
Habitat
Modification
3/
14%
6/(
2
States)
Industrial
Discharges
3/
26%
6/
18%
Non­
point
Sources
4/
14%
2/
33%
Atmospheric
Deposition
5/
13%
4/
24%
Construction
7/
7%
2/(
3
States)
Land
Disposal
7/
11%
3/
28%
Resource
Extraction
7/
10%
7/
12%
Septic
Tanks
4/
24%
Forestry
5/
10%
Silviculture
5/(
2
States)

For
groundwater,
sources
of
pollution
most
commonly
reported
are
leaking
underground
storage
tanks,
septic
systems,
landfills,
industrial
facilities,
and
fertilizer
applications.
Ground
water
data
collection
under
Section
305(
b)
is
still
too
immature
to
provide
comprehensive
national
assessments.

Contact:
Barry
Burgan
202/
566­
1242;
OWOW,
Assessment
&
Watershed
Protection
Division
Short­
term
Followup:

Long­
term
Followup:
