Refining TMDLs for the

Indian River Lagoon

Virginia Barker

Tony Janicki

Steve Peene

Harvey Harper

Claudia Listopad

Gordon England

IRL Economic Fast Facts 2007

• $1.2 B in economic benefits to Brevard

• 3,100 full and part time jobs in Brevard

• $112 M in State and local tax revenues

Algal Blooms

• 2011 Algal Super Bloom (Unprecedented in magnitude and duration)

• 2011 Secondary Bloom

• 2012 Brown Tide

• 2013 Brown Tide Returns

Florida Fish and Wildlife Conservation

Commission (FWC) Assesses Wildlife

Health

Unusual Mortality Events • Manatees - 223

• Bottlenose Dolphins - 74 Deaths

• Brown Pelicans - 300+

Major Nitrogen Sources in the IRL (Based on 2009 TMDL Report for the IRL)

Point Sources 1%

Atmospheric Deposition

19%

Stormwater 80%

IRL TMDL Update/Refinement

Major Concerns

•Compounded conservativism

load reductions too high

•Soil hydrologic groups

•Groundwater/base flow

•Air deposition changes

•Regression model simplicity

•Sea Level Rise

IRL TMDL Update/Refinement

Lagoon

Segment

Load Reduction

per TMDL

Target-Compliant

Years

Seagrass

Depth Target

% TN % TP 01 03 05 06 07

BR7 56% 69% 1.42

IR12 52% 48% x 1.39

IR14-15 52% 48% x x x x 1.39

IR16-20 51% 47% x x x x x 1.18

BR6 50% 68% x x x x 1.63

IR13 45% 46% x x x x x 1.35

BR1-2 42% 65% x x x x 1.75

IR 21 30% 44% x x x 1.52

BR3-5 28% 55% 1.57

IR9-11 25% 46% x 1.81

IR4 24% 45% 1.57

IR5 22% 44% 1.72

IR1-3 21% 41% 1.6

IR6-7 21% 43% x 1.54

IR8 21% 44% 1.57

Need for Updating the TMDL for the IRL

TN Reductions versus Seagrass

Advancing Restoration of the IRL

Working Groups

•Estimating Nutrient Loads

•TMDL Risk Assessment

•Refining the TMDL

•Air Deposition

•Fertilizer Ordinance

•Public Outreach

•FL Yards and

Neighborhoods

•Low Impact Development

•Muck Removal/Algae

Harvesting

•Capital Improvement

Partnerships

•Mapping Stormwater

Assets

•Street Sweeping

•Monitoring

IRL TMDL Update/Refinement Consortium

The City of West Melbourne

Updating/Refining the TMDL

for the IRL

Purpose of the Study:

•Build local confidence in load

reduction targets

•Build local confidence in the

allocation of responsibility

Method:

•Assemble a team of experts

•Use data collected through 2010

•Increase temporal resolution and

geo-spatial accuracy

• Estimate monthly loads

• Identify resource of concern

• Set resource targets

–Define metric

–Define spatial extent

–Define reference period

• Define relationship of loads to resource

• Estimate TMDL

TMDL REVISION STEPS

• TN and TP Baseflow and Runoff Loads from SWIL Model

• Atmospheric Loads from rainfall distribution used in watershed model and local nitrogen and phosphorus deposition data

• Point Source loads from DMR data

DEVELOPMENT OF TOTAL LOADS

SUB-LAGOONS

TN LOAD DISTRIBUTION

TP LOAD DISTRIBUTION

• Evaluated the system response to the loadings in terms of TN and TP sub-lagoon concentrations

• Simplified load-transport model using EFDC transport

• Identified potential internal sources or sinks of nitrogen and phosphorus

MASS BALANCE ASSESSMENT

MASS BALANCE

• Impairment due to seagrass loss

• DEP dictated need to relate loads to seagrass

TMDL REVISION STEPS

SEAGRASS

LOADING Water Quality

•Chlorophyll •Color •Turbidity

Water Clarity

• Define metric

– Deep Edge

– Area

TMDL REVISION STEPS

IRL North IRL Central Banana River

• Deep Edge and Area are highly correlated

• Higher uncertainty with Deep Edge estimate

• Therefore, Area is recommended metric

• Define spatial extent/segmentation

TMDL REVISION STEPS

• DEP Estuarine Nutrient Regions

–with inclusion of Newfound Harbor and Sykes Creek Estuary in Banana River

– exclusion of Sebastian River

TMDL REVISION STEPS

• Define spatial extent

• Define reference period

TMDL REVISION STEPS

• Define reference period TMDL REVISION STEPS

• The recommended reference period is 2003-2009

Proposed Target

Proposed Target

Proposed Target

PROPOSED SEAGRASS TARGETS

IRL North 20,577 acres IRL Central 8,708 acres Banana River 22,475 acres

TMDL REVISION STEPS

• Define relationship between loads and resource

TMDL REVISION STEPS

Se

agra

ss

Are

a

Load

• •

• •

•

•

•

• •

•

•

•

LOAD VS SEAGRASS REGRESSIONS

• Area - current annual loads

• Area – previous annual loads

• Area – 6, 12, 18, 24 month cumulative loads – 6-month best fit

• Area – 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 month cumulative loads - 5-month best fit

• 3-sublagoon model - Area – 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 month cumulative loads

- Loads normalized by sublagoon volume - seagrass area normalized to 2007

5-month best fit

TMDL REVISION STEPS

TN Loading Target=

3.09 lbs/acre-ft/7-months

Seagrass Target

= 8,827 acres

TP Loading Target=

0.38 lbs/acre-ft/7-months

Seagrass Target

= 8,827 acres

Comparison to DEP TMDL (January-May Loads)

• BRL DEP Current Study – TN 85,000 lbs 114,000 lbs

– TP 7,000 lbs 10,000 lbs

• NIRL – TN 197,000 lbs 226,000 lbs

– TP 16,000 lbs 21,000 lbs

• CIRL – TN 253,000 lbs 384,000 lbs

– TP 43,000 lbs 47,000 lbs

Next Steps

• Meet with DEP next week

• Finalize TMDL refinements

• Seek FDEP and EPA approval

• Implement through revised BMAPs

• Monitor success/adapt as needed

Annual vs. Jan-May

Sources of TN Loading

Annual vs. Jan-May

Sources of TP Loading

Scale of Landscape Nitrogen Loadings

Based on Literature Values

Atmospheric Deposition

Septic System Loadings

Fertilizer Loading

•Average Atmospheric Deposition Loading for the IRL

•Average Loading for Properly Sited and Maintained Septic

Systems

•Loading Allowed by Florida’s State Model Fertilizer Ordinance

Nitrogen Leaching from

Fertilizer

Relative Nitrogen Leaching

Based on Literature Values

Following State Model Fertilizer Ordinance

Requiring 50% Slow Release

Fertilizer

Atmospheric Deposition

Drainfield Leaching

Fertilizer Leaching

1

2

3

http://www.bluelifefl.org/blue_lifestyle.html

Indian River Lagoon

TMDL Revision

QUESTIONS

Presenters:

Virginia Barker, Brevard County

Tony Janicki, Janicki Environmental

Steve Peene, ATM