Transcript Document

NC Division of Water Quality
Water Quality Assessments
and
Local Watershed Plans
DWQ Tasks
1. Compile and review existing data
–
–
What is known about the watershed
What needs to be known to help develop management
strategies to improve water quality
2. Develop a monitoring plan
–
Conduct appropriate assessments, e.g. chemical,
biological, etc.
3. Report on results integrating results of
all assessments
Types of Water Quality Assessments
Conducted by DWQ
• Chemical Monitoring (includes field
measurements)
• Biological Monitoring – benthos and/or fish
• Habitat Assessments
• Wetland Functional Assessments (new in 2008)
Why Use Chemical Monitoring?
Benefits
Limitations
• Quantitative
• Expensive
• Can pinpoint locations of
problems
• Requires many samples
to characterize pollutant
effects in a watershed
• Identify the specific nature
of problems
• A sample represents only
a single point in time
Types of Measurements
• Field – Dissolved Oxygen, pH, specific
conductance, water temperature
• Nutrients – Nitrogen and phosphorous
• Solids (e.g. total suspended solids)
• Turbidity
• Metals
Example of Results - Chemistry
Ammonia nitrogen at Q8360000 -- Goose Cr. @ SR 1524 nr. Mint Hill
100
NH3 as N (mg/L)
10
Note reduction in NH3
concentrations,
beginning in August 2006
1
0.1
0.01
0.001
1996
1997
1998
1999
2000
2001
2002
2003
Year
2004
2005
2006
2007
2008
2009
2010
Why Conduct Biological Monitoring?
Benefits
Limitations
• Aquatic organisms found in • Semi-quantitative
all habitats
• Easily and inexpensively
collected
• Does not identify the
source of pollution or the
specific pollutants
• Integrates the effect of
• Seasonality & taxonomic
mixtures of pollutants over
inconsistencies
the life cycle of the
organism
Benthic
Macroinvertebrates
• Benthic - The community of organisms
living in or on the bottom or other substrate
in an aquatic environment
• Macro - Large enough to be seen by the
unaided eye and which can be retained by a
U.S. standard no. 30 seive (0.6 mm
openings)
• Invertebrate - animals without backbones
Benthic Macroinvertebrates Include
•
•
•
•
•
•
•
•
•
Ephemeroptera - Mayflies
E
Plecoptera - Stoneflies
Trichoptera - Caddisflies
Odonata - Damsel and Dragonflies
P
Coleoptera - Beetles
Megaloptera - Dobson and Alderflies
Diptera - True Flies
Oligochaeta - Aquatic Worms
Crustacea - Crayfish, Amphipods, T
Isopods
• Mollusca - Snails and Clams
Mayfly
Stonefly
Caddisfly
P
E
T
Unimpacted Site- greater diversity and number
of individuals
Assigning Bioclassifications
Using Macroinvertebrates
• Taxa Richness (number of species)
– Total number of species
– Total number of EPT species
• Biotic Index (uses a species’ tolerance to pollution
and measures of species abundances)
– Species are assigned a “tolerance value” (range 0 to 10)
– A Biotic Index (BI; range 0 to 10) is a weighted
average of the “abundance” and “tolerance value”
– Higher BI values indicate poorer conditions (i.e., more
tolerant species present)
Benthos Data for Goose/Crooked Creeks
Location
Sample
Method
Number of
Species
(1998) Ut Stevens Cr - Thompson Rd.
(1995) S Fk Crooked Cr - upstream of SR 1515
(1995) S Fk Crooked Cr - SR 1515
Crooked Creek
EPT
Biotic Index
(1995) S Fk Crooked Cr - SR 1367
(2000) N Fk Crooked Cr - SR 1520
(1995) N Fk Crooked Cr - SR 1520
(2000) N Fk Crooked Cr - SR 1514
(1995) N Fk Crooked Cr - SR 1514
(1995) N Fk Crooked Cr - SR 1004
(2006) Crooked Cr - SR 1547
Full Scale
Full Scale
EPT
Full Scale
EPT
EPT
Full Scale
EPT
Full Scale
EPT
EPT
Full Scale
Full Scale
Full Scale
EPT
(2001) Crooked Cr - SR 1547
(1996) Crooked Cr - SR 1547
(1998) Duck Cr - US 601
(1998) Goose Cr - SR 1547
(1998) Goose Cr - SR 1533
(1998) Goose Cr - SR 1525
(1998) Goose Cr - SR 1524
(1998) Goose Cr - SR 1004
(1998) Goose Cr - near Lake Dr.
(1998) Goose Cr - Glamorgan Rd.
(2006) Goose Cr - US 601
(2001) Goose Cr - US 601
(1998) Goose Cr - US 601
100
75
50
25
(1996) Goose Cr - US 601
EPT species
NonEPT
BioClassification
Not Impaired
Good
Poor
Fair
Fair
Fair
Fair
Fair
Good-Fair
Fair
Good-Fair
Good-Fair
Fair
Fair
Fair
Fair
Poor
Good-Fair
Good-Fair
Fair
Good
Fair
Poor
Full Scale
Full Scale
Full Scale
Full Scale
Full Scale
Full Scale
Full Scale
Full Scale
Full Scale
Full Scale
(1998) Stevens Cr - Maple Hollow Rd.
Goose Creek
Biotic Index
Poor
Poor
2
4
6
8 10
2
4
Lower BI scores =
better water quality
6
8 10
Contact Information:
NC Division of Water Quality
Tom Yocum
(336) 771-4953
Steven Kroeger (919) 733-9726