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)

• Quantitative

• Can pinpoint locations of problems

• Identify the specific nature of problems

• Expensive

• Requires many samples to characterize pollutant effects in a watershed

• A sample represents only a single point in time

Why Use Chemical Monitoring?

Benefits Limitations

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 - ChemistryAmmonia nitrogen at Q8360000 -- Goose Cr. @ SR 1524 nr. Mint Hill

Year

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

NH

3 as

N (

mg/

L)

0.001

0.01

0.1

1

10

100

Note reduction in NH3concentrations, beginning in August 2006

• Aquatic organisms found in all habitats

• Easily and inexpensively collected

• Integrates the effect of mixtures of pollutants over the life cycle of the organism

• Semi-quantitative

• Does not identify the source of pollution or the specific pollutants

• Seasonality & taxonomic inconsistencies

Why Conduct Biological Monitoring?

Benefits Limitations

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• Plecoptera - Stoneflies• Trichoptera - Caddisflies• Odonata - Damsel and Dragonflies• Coleoptera - Beetles• Megaloptera - Dobson and Alderflies• Diptera - True Flies• Oligochaeta - Aquatic Worms• Crustacea - Crayfish, Amphipods,

Isopods• Mollusca - Snails and Clams

Mayfly

Stonefly

Caddisfly

P

E

T

P

E

T

Unimpacted Site- greater diversity and number of individuals

Assigning BioclassificationsUsing 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 CreeksNumber of

Species

25

50

75

10

0

(1996) Goose Cr - US 601

(1998) Goose Cr - US 601

(2001) Goose Cr - US 601

(2006) Goose Cr - US 601

(1998) Goose Cr - Glamorgan Rd.

(1998) Goose Cr - near Lake Dr.

(1998) Goose Cr - SR 1004

(1998) Goose Cr - SR 1524

(1998) Goose Cr - SR 1525

(1998) Goose Cr - SR 1533

(1998) Goose Cr - SR 1547

(1998) Duck Cr - US 601

(1996) Crooked Cr - SR 1547

(2001) Crooked Cr - SR 1547

(2006) Crooked Cr - SR 1547

(1995) N Fk Crooked Cr - SR 1004

(1995) N Fk Crooked Cr - SR 1514

(2000) N Fk Crooked Cr - SR 1514

(1995) N Fk Crooked Cr - SR 1520

(2000) N Fk Crooked Cr - SR 1520

(1995) S Fk Crooked Cr - SR 1367

(1995) S Fk Crooked Cr - SR 1515

(1995) S Fk Crooked Cr - upstream of SR 1515

(1998) Stevens Cr - Maple Hollow Rd.

(1998) Ut Stevens Cr - Thompson Rd.

EPT species NonEPT

2 4 6 8 10 2 4 6 8 10

SampleMethodLocation

Full Scale

Full Scale

Full Scale

Full Scale

Full Scale

Full Scale

EPT

Full Scale

EPT

EPT

Full ScaleFull Scale

Full Scale

Full Scale

Full Scale

Full Scale

Full Scale

Full ScaleFull Scale

EPTEPTFull ScaleEPTFull Scale

EPT

Good

Good-Fair

BioClassification

Not Impaired

Poor

FairFair

FairFairFair

FairGood-Fair

Good-FairFairFairFair

FairPoorGood-Fair

Good-Fair

FairGoodFairPoor

Poor

Poor

Biotic IndexEPT

Biotic Index

Lower BI scores =

better water quality

Go

os

e C

ree

kC

roo

ke

d C

ree

k

Contact Information:

NC Division of Water Quality

Tom Yocum (336) 771-4953

Steven Kroeger (919) 733-9726