Non-Point Nitrogen Sources and
Transport Pathways in the Great Bay
Watershed
University of
New Hampshire
Michelle L. Daley
UNH Dept. Natural Resources & the Environment
NH Water Resources Research Center
NH Water and Watershed Conference – March 22, 2013
University of
New Hampshire
Great Bay
University of
New Hampshire
• Long-term increase in
dissolved inorganic nitrogen
(DIN) concentrations
• Macroalgae problems
• Low dissolved oxygen (DO) in
tidal rivers
• Loss of Eelgrass, Clams and
Oysters
• Increased suspended
sediment and decreased
clarity
Nutrient thresholds
To protect:
– DO (0.45 mg TN/L)
– Eelgrass (0.30 mg TN/L)
Photo credit: Dr. Fred Short
University of
New Hampshire
Nitrogen
Impairments
for Great Bay
Estuary
Violation of Clean
Water Act
Great Bay Watershed
University of
New Hampshire
• Home to 22% of NH’s population
• Drains 52 towns (42 NH; 10 ME)
• Mostly forested, no big agriculture
and some development
• Point sources - 18 WWTF (32%)
– 10 discharge to estuary
– 8 discharge to tributaries
• Non-point N sources (68%)
–
–
–
–
–
Septic systems and leaky sewer lines
Fertilizers
Pets and livestock waste
Atmospheric deposition
Wetlands, forests and soils
Forms of Nitrogen (N) and
Trends in the Lamprey
University of
New Hampshire
Dissolved N
Particulate N
Attached to sediment and increases
with flow; no data on variability with
land use in Lamprey or Great Bay
“Reactive”
Nitrogen
Associated with
Human Activity
in Lamprey
Dissolved Inorganic
Nitrogen
Nitrate
(NO3-)
Dissolved Organic
Nitrogen (Associated
with wetlands not
humans in Lamprey)
Ammonium
(NH4+)
Used 10+ years of data to examine trends in the Lamprey (and Oyster)
University of
New Hampshire
NERRS Science
Collaborative Project
Nitrogen Sources and Transport Pathways:
Science and Management Collaboration to
Reduce Nitrogen Loads in the Great Bay
Estuarine Ecosystem
Investigators: Dr. William H. McDowell, Dr.
John Bucci, Dr. Erik Hobbie, Dr. Charlie French,
Michelle Daley, Jody Potter and Steve Miller
University of
New Hampshire
Nitrogen Sources and Transport
Pathways Objectives
Objectives:
1. Integrate scientific investigations with stakeholders to ensure
results are useful and accessible to environmental managers and
other stakeholders
2. Identify, model and map N concentrations in surface waters
throughout the Great Bay Watershed to identify “hot spots”
3. Identify non-point sources of N that reach surface waters and the
delivery pathway (e.g. groundwater vs. stormwater) using tracers.
4. Quantify N attenuation in large river reaches with modeling
Project Duration: Fall 2010 to Summer 2014
University of
New Hampshire
Nitrogen Sources Collaborative
Advisory Board (NSCAB)
• More than 15 members representing a diverse
group of stakeholders including:
– municipal planners and decision-makers
– representatives of non-profit organizations
– local and regional businesses
• Approximately quarterly meetings to present
preliminary data, discuss findings, next steps
and potential products
University of
New Hampshire
Great Bay Nitrogen Sources
Newsletter: Nitrogen Newsbytes
To subscribe, email:
charlie.french@unh.edu
• Over 130 subscribers
representing diverse interests:
– Sewer districts
– Municipal planners and decision
makers
– Conservation and watershed
organizations
– taxpayers
– national Senator staffers (Shaheen)
• Released quarterly before
NSCAB meeting
University of
New Hampshire
NSCAB Field Trip
(July 2012)
NSCAB Field Trip Video
University of
New Hampshire
http://www.youtube.com/watch?v=LHvf5HpTKuk
University of
New Hampshire
Measure N
Concentrations
at ~250
“Extensive” sites
Total Nitrogen
• Dissolved inorganic N (DIN)
- Nitrate (NO3)
- Ammonium (NH4)
• Dissolved organic N (DON)
• Particulate N
Google
Earth
file
(kmz) of
Sites
University of
New Hampshire
http://wrrc.unh.edu/great-bay-non-point-nitrogen-sources
Google
Earth
file
(kmz) of
Sites
University of
New Hampshire
University of
New Hampshire
Current N
Conditions
Map
(Median Total
Dissolved Nitrogen)
Sampled 5 times:
Oct. 2010, May 2011 and
3 times summer 2012
University of
New Hampshire
Sub-basin Landscape Assessment
for Extensive Sites
• NHGS delineating sub-basins using NH Hydrography Dataset and 10
m DEM network
• Quantify population density, impervious surfaces and land use with
assistance from NHGS
• Quantify N inputs using the Great Bay Non-Point Nitrogen Pollution
Source Study (NHDES) methods and customized data layers
–
–
–
–
–
–
–
Septic systems (2010 Census blocks)
Managed turf (municipal turf and golf courses) fertilizer
Residential turf fertilizer
Agricultural fertilizer (2011 USDA cropland data)
Livestock and pet feed inputs (2007 census of agriculture, pets registrations)
Atmospheric deposition (local and out-of-state sources)
Impervious surfaces (total and directly connected)
• Relate N concentrations to
landscape characteristics
and N inputs from GBNPSS
- Does DIN respond to
human activity like it does
in the in the Lamprey?
- Are other features
important for Inorganic N?
e.g. Agriculture?
- Does DON respond to
human activity?
• Identify N “hot spots”
Hypothetical
Discharge-Weighted Mean NO3-N (mg/L)
University of
New Hampshire
Generate Great Bay
Landscape Models
DO
Criterion
1
0.45
mg/L
0.1
0.01
0.1
1
10
100
1000
2
Human Population Density (people/km )
- high N or outlier sites (higher or lower N than expected
Current N prediction Maps
University of
New Hampshire
• Use Great Bay landscape
models to profile
catchments at risk for
elevated non-point N
• Apply to ~3500 NHGS
catchments (<0.008 to 7 mi2)
• Produce maps for the 40
HUC 12 sub-watersheds
and 52 towns
N level
Low
Medium
High
1st Generation
University of
New Hampshire
Multi tracer approach to identify the
dominant non-point N sources
delivered to surface waters
• Stable Isotopes
– Nitrate (NO3-) isotopes – 15N and 18O to distinguish
between atmospheric, fertilizer and animal waste source
– Sediment isotopes – 15N of surficial sediment (2 cm) to
distinguish between fertilizer and animal waste
• Microbiological source tracing – mitochondrial (mt) DNA to
identify human, Bovine or Dog waste
• Chemical to identify human waste
– Caffeine
– Optical brighteners – laundry detergents
• Pharmaceuticals in collaboration with EPA to identify human
waste
Tracer Testing and Application at
Intensive study sites (n = 10-20)
University of
New Hampshire
1. Test known sources to build our tracer toolbox
– Small watersheds with uniform land-use
•
•
•
•
•
All septic (sub-urban) and all sewered (urban)
Agricultural to identify livestock waste
Golf course site to identify fertilizers
Parking lot drainage
Forested as a control site
2. Apply tracer methods in combination to “hot spot”
sites to identify dominant source of non-point N
– Sample streams, shallow groundwater, storm events to
characterize transport pathway
Nitrate Isotopes
University of
New Hampshire
• Pavement drainage –
water from parking lot
not stormwater pipe
• Animal waste source at
urban (sanitary sewer),
suburban (septic) and
agriculture sites
• Pavement drainage in
stream draining Pease
airport strip
• Denitrification in
agricultural Groundwater
Denitrification
Mitochondrial DNA
University of
New Hampshire
Site
Land Use
Henry Law Park
Brook
Urban
Berry Brook
Urban
Gosling Road
Unnamed Brook
Urban
Hodgson Brook
Urban
CB03
Urban/Agriculture
Present (N=2)
PB02.7
Urban
MLB01
Urban
WHB01
Suburban
BDC
Agriculture
Absent (N=6)
PWT07
Reference
Low Presence
(2 out of 5)
Human
Bovine
Dog
Low Presence
(1 out of 2)
Low Presence
(1 out of 2)
Present
(2 out of 3)
Present
(1 out of 2)
Low Presence
(N=2)
Absent (N=2)
Absent (N=2)
Absent (N=2)
Present
(1 out of 3)
Low presence
(1 out of 2)
Present
(1 out of 2)
Present (N=2)
Absent (N=2)
Absent (N=2)
Absent (N=1)
Present
(8 out of 8)
Present
(5 out of 9)
Low presence
(1 out of 6)
Low Presence
(1 out of 7)
Present
(3 out of 4)
Low Presence
(1 out of 5)
Low presence
(1 out of 7)
Absent (N=3)
Absent (N=2)
Absent (N=7)
Absent (N=4)
Absent (N=5)
Pharmaceuticals
University of
New Hampshire
Atenolol
Site
Berry Brook
Berry Brook
Gosling Brook
Gosling Brook
Hodgson Brook
Borthwick Ave Trib
CB03
PB02.7
MLB01
MLB01
WHB01
WHB01
WHB01 (well)
PWT07
Land Use
Urban
Urban
Urban
Urban
Urban
Urban
Urban/Ag
Urban
Urban
Urban
Suburban
Suburban
Suburban
Reference
Reporting
Limit (ng/L)
Acetaminophen Cotinine 1,7-Dimethylxanthine Caffeine
Beta
Blocker,
High Blood
Pressure
ND
ND
ND
ND
ND
11
ND
ND
ND
ND
ND
ND
ND
ND
Pain Reliever
3
2.9
8.2/13
ND
ND
100
14
ND
2.3
ND
ND
ND
ND
ND
Metabolite
of Nicotine
2.8
1.8
59/43
5.3
10
11
15
5
0.74
0.58
0.4
BDL
1.9
0.7
Metabolite of
caffeine
3.1
8.6
29/40
5.6
5.7
70
7.7
2.1
7.9
3.5
ND
2.5
9.3
ND
2
2
0.4
2
Carbamazepine
Metoprolol
Anti- depressant
/ bi-polar or
Beta Blocker,
Natural Anti-convulsant High Blood
Stimulant
(epilepsy)
Pressure
14
ND
ND
30
ND
BDL
1500
0.29/0.58
ND
40
ND
ND
280
ND
ND
540
BDL
13
200
ND
ND
97
ND
ND
9
ND
ND
78
ND
ND
ND
4.1
ND
9.8
1.6
ND
27
4.3
ND
ND
ND
ND
4
0.4
2
University of
New Hampshire
N attenuation in large
freshwater river reaches
• Quantify N attenuation in
large river reaches by
modeling N inputs and
outputs and inferring N
attenuation
• N attenuation = N load at
outlet
– upstream N load
– tributary N loads
– N load for riparian area
• EPSCoR river network
modeling by Kyle
Whittinghill, Madeleine
Mineau and Wil Wollheim
Summary
University of
New Hampshire
• Approximately 50% of extensive sites exceed the TN
threshold for protecting DO in tidal rivers
• Human waste evident in suburban and urban
streams (septic systems and leaky sewer lines)
• Bovine mt DNA detected at agricultural sites and low
presence at surburban/urban sites may result from
human waste
• Dog mt DNA detected in 1 or 2 streams
• Atmospheric deposition or pavement drainage
detected in one stream
• Isotopes have not have not identified fertilizers yet
University of
New Hampshire
A River, Estuary or Lake is a
Reflection of its Watershed
Questions?
Michelle Daley
mldaley@unh.edu
603-862-2341