Analysis of Florida’s Benchmark Streams for Establishing Numeric

Nutrient CriteriaErik B. Schilling

National Council for Air and Stream Improvement, Inc.Southern Regional Center

Newberry, FL&

M. Cohen, D. McLaughlin and J. DiamondUniversity of Florida

School of Forest Resources and Conservation Gainesville, FL

Project Goals

• Enhance the analysis of FL ‘benchmark streams’ for stream nutrient criteria development to include:– Role of stream flow (which is currently not explicitly part

of the numeric standards) – Conduct a new data synthesis to better understand controls

on stream DO dynamics• Conduct a paired watershed monitoring to test FL

fertilization BMPs – Pre-fertilizer treatment baseline flow– WQ sampling using deployable sensors and discrete water

sampling

State Numeric Nutrient Criteria"Adoption Milestones" (reported to EPA)

...among key forestry industry states...

State Numeric Nutrient Criteria"Adoption Milestones" (reported to EPA)

...among key forest industry states...

• Date delayed for up to six years beyond orig. milestone (7 states): AL, GA, MN, MS*, OH, PA, WI**

• Date withdrawn; e.g., changed from 2012 to "No date provided" (8 states):  LA, ME, SC, TN, TX, VA, WA, WI**

• "No Date"/unchanged (4 states): AR, MI, NC, OR

*Mississippi: 2‐year delay for Delta waters**Wisconsin: previously TN criteria by 2009;now 2015 for rivers/streams, and "no date"for lakes/reservoirs.

• On‐track (3 states): FL, NY (by 2013), and MS (non‐Delta waters).

• Met target date for at least one parameter‐waterbody type combination (4 states):– SC '04: lake TP in most ecoregions.– VA '07: lake TP & chl‐a (specific).– WI '07: TP for waters by use class.– MN '08: TP & chl‐a (class 2A lakes).

Florida’s NNC Development Costs(as of 2010)

Florida’s Proposed Numeric Nutrient Criteria

Data Synthesis: Stream Dissolved O2

• Objectives: Determine Drivers of DO Dynamics

• >150 Florida Streams

• Quarterly 3-Day Deployments (DO sampled 15-min intervals)

• Data for SCI, LDI, NOx, TKN, TP, TOC, Chl a, Color

• Large variation among sites:High DO sites: some with no variation, others with systematic diurnal variation

The same holds true for moderate and low DO sites 0

2

4

6

8

10

12

0:00 6:00 12:00 18:00 0:00 6:00 12:00 18:00 0:00 6:00 12:00 18:00

DO

(mg/

L)

Nutrient Criteria Development –Biological Health

• Stream Condition Index (SCI) is an examination of stream benthic macroinvertebrate communities– The SCI has 10 metrics (scored from 0 to 100)

• For these indices, a human disturbance gradient (LDI) approach was utilized to identify community attributes that respond predictably to human stress – Consists of landscape, habitat, hydrological, and water quality factors that are scaled to approximate the human disturbance present at a series of sites

SCI and DOy = 2.24x + 25.11

R² = 0.09

0

20

40

60

80

0.0 2.0 4.0 6.0 8.0 10.0

SCI

Mean DO (mg/L)

y = 3.08x + 22.52R² = 0.18

0

20

40

60

80

0.0 2.0 4.0 6.0 8.0 10.0

SCI

10% Deployment (mg/L)

As we expected, stream condition (via SCI) is more influenced by minimum DO (10% deployment) and daily range of DO than it is by mean DO.

y = -4.72x + 44.72R² = 0.25

0

20

40

60

80

100

0 2 4 6 8 10 12

SCI

Daily Range (mg/L)

However, limited (if any) effects of nutrients on DO (Minimum and DO Daily Range)

y = -0.88x + 5.03R² = 0.01

0.0

2.0

4.0

6.0

8.0

10.0

0.00 0.50 1.00 1.50 2.00 2.50 3.00

10%

Dep

loym

ent (

mg/

L)

TP (mg/L)

y = 1.03x + 4.74R² = 0.02

0.0

2.0

4.0

6.0

8.0

10.0

0.00 0.50 1.00 1.50 2.00

10%

Dep

loym

ent (

mg/

L)

NOx (mg/L)

y = -0.11x + 1.51R² = 0.00

0

2

4

6

8

10

0.00 0.50 1.00 1.50

Dai

ly R

ange

(mg/

L)

NOx (mg/L)

y = 0.99x + 1.36R² = 0.01

0

2

4

6

8

10

0.00 0.20 0.40 0.60 0.80 1.00

Dai

ly R

ange

(mg/

L)

TP (mg/L)

Land Use (via LDI) does not influence nutrients, but does influence DO range (shading?)

y = 0.46x + 0.12R² = 0.33

0.0

4.0

8.0

12.0

0 2 4 6 8 10

Ran

ge (m

g/L

)

LDI

y = 0.02x + 0.07R² = 0.07

0.0

0.4

0.8

1.2

1.6

2.0

2.4

0 2 4 6 8 10

TP

(mg/

L)

LDI

y = 0.01x + 0.14R² = 0.00

0.0

0.4

0.8

1.2

1.6

0 2 4 6 8 10

NO

x (m

g/L

)

LDI

Note: LDI values range from 1 to10. Streams with LDI scores < 2.0 are considered to be least impaired. Forest plantations have a LDI value of 1.58 (Reiss and Brown, 2007)

Thus, LDI affects SCI, but not through nutrient effects to DO dynamics.

y = -4.37x + 50.83R² = 0.33

0.010.020.030.040.050.060.070.080.090.0

0 2 4 6 8 10

SCI

LDI

Initial Conclusions

• DO dynamics of FL’s benchmark streams are influenced by climate, riparian vegetation, geomorphology, etc.– Streams can naturally have low DO regimes

• Continuing analyses to investigate the natural drivers of DO dynamics– Should be considered when relating nutrients to

DO dynamics and ultimately stream health

FL Fertilization BMP Effectiveness Study Watersheds

Simms Creek Watershed

Santa Fe Drain

Watersheds range between 5,500 to 7,500 ac. Plantations

make up >60% of the total area; wetlands comprise >30%.

Typical Coastal Plain BlackwaterStreams with Traditional Pine 

Management

Hydrology and Water Quality Sampling

• Continuous flow/stage measurement– Pressure transducers

• Continuous monitoring (hourly to sub-hourly)– Sonde (DO, temperature, pH and

SC) – Wetlabs PO4 (reactive-P) – Wetlabs Triplet (DOM, turbidity)– Satlantic SUNA (UV nitrate

analyzer)• Weekly sampling

– P (soluble, total, particulate)– N (inorganic, organic, particulate)– Color, pH, DO and specific

conductance

0

0.02

0.04

0.06

0.08

10

15

20

25

1/18/13 12:00 1/19/13 12:00 1/20/13 12:00 1/21/13 12:00 1/22/13 12:00

Nitrate (ppm

)

Ort

ho-P

O4

(ppb

), Te

mpe

ratu

re (C

)

Ortho-PO4 (ppb)Temp (C)Nitrate (ppm)

50

55

60

65

70

75

80

170

174

178

182

186

190

Dissolved O

xygen (% sat)

CD

OM

(ppb

)

CDOM (ppb)DO (% sat)

0.000

0.005

0.010

0.015

0.020

0.025

0.30

0.31

0.32

0.33

0.34

0.35

0.36

0.37

0.38

0.39

0.40

1/18/13 12:00 1/19/13 12:00 1/20/13 12:00 1/21/13 12:00 1/22/13 12:00

Hydraulic G

radient (m)

Wat

er D

epth

(m)

Upstream Water DepthDownstream Water DepthHydraulic Gradient

A four day period showing in situ, high resolution water quality and hydrologic data. Note the systematic diurnal signatures.

Questions?