Nutrient Fluxes in the New River, NC: The Dark Side of Hog Farms Rae Mooney Hydrology May 1, 2007.

Nutrient Fluxes in the New River, NC:The Dark Side of Hog Farms

Rae Mooney

Hydrology

May 1, 2007

New River Watershed

• 1,436 km2

• Fisheries– Economy– Recreation

• Home to 138 CAFOs– July 1995: Holding pond

ruptures on New River– 25 million tons of hog

waste Mallin et al., 2005

Map of Study Area

&3

&3

&3

"/"/

"/ "/

"/"/ "/ "/

"/"/Legend

"/ UNCW-Sampling Sites

&3 StreamGages_NewRv

NHDFlowline_NewRv

flowlineattributesflow.MAFLOWU

0.00088 - 13.06333

13.06334 - 47.97963

47.97964 - 97.81542

97.81543 - 272.71247

272.71248 - 489.09477

NHDwaterbody_NewRv

NewRiverSubbasin

LULC

Value

Developed

Forest/Scrub/Grassland

Agriculture

Wetlands

M52

172

Percentages of LULC

LULC in the New River Estuary

7%

44%

15%

34%Developed

Forest/Scrub/Grassland

Agriculture

Wetlands

Effects of Hog Farms and other Agriculture

• Increased Eutrophication– Waste ponds overflow– Spray waste on fields – “overapplication”– Now, LESS farms w/ MORE HOGS

• TOXIC and harmful to humans– Discharge – more than waste– Harmful Algal Blooms

• Secrete toxins • Seafood – toxic to eat

LOADEST: Load Estimator

• Estimates constituent loads using Linear Regression

• Input: daily streamflow, data variables, monthly constituent concentrations

• Output: daily constituent concentrations, residuals, z-scores, regression statistics from models

Input Files

Output Files

Stats and ModelsSite-Constituent

Model-based on AIC PPCC

NH4-M52 2 0.9901

NH4-172 9 0.9971

NO3-M52 7 0.9907

NO3-172 9 0.9473

PO3-M52 9 0.9919

PO3-172 7 0.9919

Normal Distribution:

MLE – Max Likelihood Estimation

AMLE – Adjusted MLE (less biased)

PPCC – not normal distribution:

LAD – Least Absolute Deviation

Hurricane Floyd (500 yr Storm) – September 9-17th, 1999[NH4] 9/99 at site M52

-50000

0

50000

100000

150000

200000

250000

9/1/1999 9/9/1999 9/17/1999 9/25/1999

Time (days)

[NH

4]

kg

/da

y

0

2000

4000

6000

8000

10000

12000

Str

eam

flo

w (

cfs

)

AMLE MLE

LAD Streamflow

[NO3] 9/99 at site M52

-2000

0

2000

4000

6000

8000

10000

12000

9/1/1999 9/9/1999 9/17/1999 9/25/1999

Time (days)

NO

3 C

on

cen

trat

ion

(k

g/d

ay)

0

2000

4000

6000

8000

10000

12000D

isc

ha

rge

(c

fs)

AMLE MLE

LAD Streamflow

[PO3] at site M52, 9/99

-500

0

500

1000

1500

2000

2500

9/1/1999 9/9/1999 9/17/1999 9/25/1999

Time (days)

PO

3 C

on

cen

trat

ion

(kg

/day

)

0

2000

4000

6000

8000

10000

12000

Dis

char

ge

(cfs

)

AMLE MLE

LAD Streamflow

[NH4] for site 172, 9/99

-2000

0

2000

4000

6000

8000

10000

12000

14000

16000

9/1/1999 9/7/1999 9/13/1999 9/19/1999 9/25/1999

Time (days)

NH

4 c

on

ce

ntr

ati

on

s

(kg

/da

y)

0

2000

4000

6000

8000

10000

12000

Dis

ch

arg

e (

cfs

)

AMLE MLE

LAD Streamflow

[NO3] 9/99 at site 172

-20.00

0.00

20.00

40.00

60.00

80.00

100.00

120.00

9/1/1999 9/9/1999 9/17/1999 9/25/1999

Time (days)

[NO

3]

(kg

/day)

0

2000

4000

6000

8000

10000

12000

Str

eam

flo

w (

cfs

)

AMLE MLE

LAD Flow

[PO3] 9/99 at site 172

-200

20406080

100120140160180200

9/1/1999 9/9/1999 9/17/1999 9/25/1999

Time (days)

[PO

3]

(kg

/day)

0

2000

4000

6000

8000

10000

12000

Ste

am

flo

w (

cfs

)

AMLE MLE

LAD Streamflow

Hurricane Floyd

[PO3] M52 & 172, 9/99

-200

0

200

400

600

800

1000

9/1/1999 9/9/1999 9/17/1999 9/25/1999

Time (days)

PO

3 C

once

ntra

tion

(kg/

day)

0

2000

4000

6000

8000

10000

12000

Str

eam

flow

(cfs

)

M52 172

Streamflow

[NH4] at M52 & 172, 9/99

-5000.00

0.00

5000.00

10000.00

15000.00

20000.00

25000.00

30000.00

35000.00

40000.00

45000.00

9/1/1999 9/9/1999 9/17/1999 9/25/1999

Time (days)

NH

4 C

on

ce

ntr

ati

on

s

(kg

/da

y)

0

2000

4000

6000

8000

10000

12000

Str

ea

mfl

ow

(c

fs)

M52 172

Streamflow

[NO3] 172 & M52, 9/99

-2000.00

0.00

2000.00

4000.00

6000.00

8000.00

10000.00

12000.00

9/1/1999 9/9/1999 9/17/1999 9/25/1999

Time (days)

NO

3 C

on

cen

trat

ion

s (k

g/d

ay)

0

2000

4000

6000

8000

10000

12000

Str

eam

flo

w (

cfs)

172 M52

Streamflow

Conclusions

• Must be careful to use BEST model

• User-friendly– sometimes

• Overall useful tool since continuous sampling impossible

Tomorrow…

• For comparison– Chat w/ scientist at N.C. Division of Water

Quality– Sampling from Hurricane Floyd

• Look at effects of new wastewater treatment plants in 1998

Questions??