3. Importance of Study
Increase in Eutrophication
o Eutrophication: a natural process of water bodies becoming
more enriched and productive through an increase in nutrient
supply (Smith et al, 1998)
o Algal Blooms
• CyanoHABs
Smith et al, 1998
Why is it important to reduce nutrients?
Eutrophic Conditions for Water Resources
Freshwater lakes 0.065-0.12 mg TN L-1
0.003 mg TP L-1
Streams >0.03 mg TN L-1
0.075 mg TP L-1
Marine >0.04 mg TN L-1
5. Importance of Study
Increase in Eutrophication
o Algal Blooms
• CyanoHABs
Human Health
o Nitrate-Nitrogen(NO3-N) concentrations
• >10mg NO3-N L-1 drinking water EPA limitations
• Methameblogmeia (blue baby syndrome)
What degrades water quality???
6. Importance of Study: North Carolina
North Carolina Division of Water Quality determined that
non-point sources of pollution such as agriculture to be
the single largest contributor of nutrients to the Neuse
River and Cape Fear River Basins (NCDWQ 1996)
http://www.learnnc.org/lp/editions/nchist-recent/6202
7. Importance of Study: North Carolina
Point and Non-point Source Pollution
o Point Source: delivered directly from discrete conveyance such
as waste water treatment plants, industrial facilities or direct
dumping of waste into streams. Point source pollutants are
federally regulated.
o Non-point Source: diffuse sources that do not have a
discernable direct source and are normally moved through the
system by runoff
• Includes oils, sediments, animal wastes, fertilizers, herbicides,
insecticides
(EPA, 1998a)
• Less regulated.
8. Importance of Study: Jordan Lake
The Jordan Lake Watershed has
pressures to decrease the
amount of sediment and nutrients
in it’s bodies of water
o Environmental Management
Commission: 1983 it placed Jordan
Lake Reservoir on a Nutrient
Sensitive Water
• Ordered limits on phosphorus
wastewater discharge
• Saw no response to controls
Additional regulations imposed in
January 2008 that affected point
and non-point (urban and ag)
sources of nutrients.
Greensboro
Chapel Hill
Durham
Burlington
JordanLake
Reidsville
Map Produced: R. Austin, D.Osmond
²
Jordan Lake Watershed
0 10 205 Miles
Cape Fear
River Basin
North Carolina State University
Department of Soil Science
North Carolina Stateplane, Zone 4901, NAD83 meters
9. Nutrient Load Reductions
required by the state of
North Carolina from the
1997-2001 baseline period
o Haw Sub Basin:
• 8% Nitrogen and 5% Phosphorus
o Upper New Hope Sub Basin:
• 35% Nitrogen and 5% Phosphorus
o Lower New Hope Sub Basin:
• 0% Nitrogen and 0% Phosphorus
Slide credit: Dr. Osmond, NCSU
10. To quantify the effectiveness of agricultural
conservation practices, such as livestock
exclusion and nutrient management, on
surface water quality in the Jordan Lake
watershed of North Carolina
11. Overview
Water Quality Monitoring:
o Automated runoff samplers
o Precipitation data
Land Use Monitoring
o Farmer surveys
Paired Watershed Design
12. Monitoring Stations:
o Automated Sampler
• ISCO 6700 and 6720
• Integrated flow meter
o Permanent staff gauge
• Stage-discharge relationships measured and adjusted periodically.
o Tipping bucket rain gauge
• 15 minute basis
17. Storm Event Samples
Continuous Rainfall
Grab Samples*
Chemical Analysis
Kjeldahl Nitrogen (TKN)
Ammonium Nitrogen (NH4-N)
Nitrate + Nitrite Nitrogen (NOx-N)
Total Phosphorus (TP)
Dissolved Phosphorus (DP)*
Bacteria (E. coli)*
Total Suspended Solids (TSS)
18. Storm Event Sampling: bi-weekly (2 week intervals)
o 125-150mL sample for TKN, NH4-N, NOx-N, and TP
• Acidified
o 250-500mL sample for TSS
• Non acidified
Grab Samples: seasonal
Storm samples are acquired within 12 hours of a storm event
Base flow samples
o Analyze for:
• Bacteria (e-Coli)
• Dissolved Phosphorus
• Analyzed within 6-8 hours
19. Overview
Water Quality Monitoring:
o Automated runoff samplers
o Precipitation data
Land Use Monitoring
o Farmer surveys
Paired Watershed Design
20. Land use monitoring:
o Collected annually through farmer surveys
• Crop(s)
• Planting and harvest dates
• Fertilizer application(s)
• Method
• Type
• Amount
• Placement
• Animal stocking density
• Diet additives
o Bi-weekly field survey
• Record visible land uses, animal stocking densities at time of
sampling.
21. Overview
Water Quality Monitoring:
o Automated runoff samplers
o Precipitation data
Land Use Monitoring
o Farmer surveys
Paired Watershed Design
22. Definition
Comparisons of adjacent sub watersheds with similar land
uses in two temporal periods:
o Pre-BMP: Before conservation practices
• No changes made to the land use practices
• 2-3 years of monitoring
• All watersheds monitored simultaneously
o Post-BMP: After conservation practices
• 2-5 years of monitoring
• 1 out of at least 2 watersheds have BMPs implemented
23. Why use paired watershed design?
o Addresses the dynamic system interactions
o Non-biased; aka no “assumptions” of how the system
interacts
o Variability of weather isn’t optimal but occurs.
• Consistent data for “typical” weather is acquired over a
long pre and post-BMP period
24. The determination of which sub-watersheds are the Control
vs. Treatment is mostly up to farmer cooperation
Pasture (L) Pasture (M)
Control and Treatment for
Pastures
Crop
(V)
Crop
(R)
Control and Treatment
Croplands
Pasture
“Pair”
Crop“Pair
”
25. The Jordan Lake Paired Watershed Study
Stages of Water Quality Monitoring:
o Pre-BMP
• Crop and Pasture: Start of 2008
o Post-BMP
• Pasture: Spring 2011 (Fertilization) and Fall 2011 (Exclusion
Fencing)
• Crop: Fall 2012
Began work at NCSU (Fall 2012)
26. • 193 ac, 40% beef and dairy pasture
• Aquic Hapludult (<6% slope)
• Soil Test M3P 166 mg kg-1
Multiple Land
Uses
27. Pre-Treatment (2008-2010)
o Cropland:
• Corn 22.1 acres (11.5%)
• 2010
• 17-17-17, 336 kg ha-1
• (300 lb ac-1)
• 85 lb N ac-1 sidedress
• Harvest mid August
• Ripped/disked in 2010
• Fallow 2008-2009
o Hayland:
• Hay 16.2 ac (8.4%)
• 2.5 tons ac-1, 2-3 times per year
• Fertilized with Pullet Manure
• 3 tons ac-1
Post-Treatment (2011-2013)
o Cropland:
• Soybean 22.1 acres (11.5%)
• 2013
• 17-17-17, 336 kg ha-1
• (300 lb ac-1)
• 85 lb N ac-1 sidedress
• Harvest mid November.
• Fallow 2011-2012
o Hayland:
• Hay 16.2 ac (8.4%)
• 2.5 tons ac-1, 2-3 times per year
• Fertilized with Pullet Manure
• 3 tons ac-1
28. Pre-Treatment (2008-2010)
Pasture
72.7 ac (37.7%)
o Dairy and Beef Cow
• Near 100 cows total
• Even mix of dairy and beef
cows.
o Fed with Additives
• Fed with hay in winter: 12% protein
additive and High Mag block.
Forest
61.3 ac (31.8%)
Post-Treatment (2011-2013)
Pasture
72.7 ac (37.7%)
o Beef Cow
• Near 80 cows total
• Mostly beef cows.
o Fed with Additives
• Fed with hay in winter: 12% protein
additive and High Mag block.
Forest
61.3 ac (31.8%)
31. Pre-Treatment Land Use:
2008-2010
Fertilizer:
o 15-15-15 at 336 kg ha-1
• (300 lb ac-1)
o Biosolids applied in April 2010
Crop: fescue for cattle
Uses additives.
Rotates cows in fields.
Post-Treatment Land Use:
2011-2013
Nutrient Management in 2011, 2012, and
2013.
o STP very high (range)
o Nitrogen fertilizer
• Under applied at 78 kg ha-1
• (70 lb N ac-1)
Livestock Exclusion by fencing
o Installed in 2011.
Continued field rotations.
Livestock average:
26 adult cow
26 calves
33. Data interpretations in preliminary stage!
o 1st - 3rd years of Post Treatment installation monitoring
• Pastures only
o End: March 2014
• (data collection not finished)
Analysis done only for Pasture Pair
o Pre and Post Treatment data for pastures only
34. Paired Watershed
studies rely on a
significant
hydrologic
relationship.
Statistical
comparison of
chemical
constituents is
reasonable.
y = 0.84x - 9817.9
R² = 0.86
y = 0.84x + 13745
R² = 0.95
0
1,000,000
2,000,000
3,000,000
4,000,000
5,000,000
6,000,000
0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000 6,000,000
Pasture-BMP(gal)
Pasture-Control (gal)
Pre & Post-BMP Period Hydrology
12/20/08-6/2/13
pre
post
35. Total Suspended
Solid Loads for only
comparable storm
events.
y = 0.78x + 172243
R² = 0.74
y = 0.47x + 52110
R² = 0.59
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
0 1,000 2,000 3,000 4,000 5,000 6,000
Pasture-BMP(kg)
Pasture-Control (kg)
Pasture Pre-BMP & Post-BMP TSS Load
12/20/08-06/02/13
pre
post
Decrease in TSS
for the treatment
watershed from
pre to post
treatment periods
41. Constituent Difference in Pasture Treatment &
Control Reductions (%)
TKN (kg/ha/yr) 30.11
NOx-N (kg/ha/yr)* -51.87*
NH4-N (kg/ha/yr)
33.19
TN (kg/ha/yr) 2.1
TP (kg/ha/yr) 30.28
TSS (kg/ha/yr) 13.69
*Did not improve by comparison after BMP installation.
42. Pasture Control (L)
Increased
o TKN
o TN
o TP
Decreased
o NOx-N
o NH4-N
o TSS
Pasture Treatment (M)
Increased
o NOx-N
Decreased
o TKN
o NH4-N
o TN
o TP
o TSS
43. Thank you!
Dr. Deanna Osmond
Dr. Garry Grabow
Dr. Matt Polizzotto
Daniel Line
Wesley Childres
Funding
o USDA NIFA
o NC DENR, USEPA 319 pass-through funds
Editor's Notes
The Jordan Lake Watershed rules are designed around nitrogen and phosphorus percentage reduction goals for each of the three subwatershed of Jordan Reservoir: Haw, Lower New Hope and Upper New Hope. Each subwatershed of the lake responds independently to nutrient inputs received from its watershed. The baseline period for establishing nutrient reductions is 1997-2001. All progress will be monitored against these dates.
Major edits needed: AH
Fix this slide: AH
Need to go check data for specifics: AH
Paired watershed studies require a significant relationship between the hydrology for the control and treatment watersheds. The strong correlation near 0.9 Rsquared indicates that there is a strong positive relationship between the hydrology of the two watersheds, which allows us to make a reasonable assumption that the control and treatment watershed have similar responses to storm events in terms of the volume of water moving through the system. It is then also reasonable to make comparisons on the nutrient constituents between the two watersheds in order to see the best management practices response on water quality. AH
Not sure if interpretation is correct. Load accounts for discharge so it shouldn’t make that much of a difference?: AH
