Florida Numerical Nutrient Florida Numerical Nutrient CriteriaCriteriaSouthwest Florida Water Southwest Florida Water Resources ConferenceResources Conference

Scott I. McClellandScott I. McClellandVice PresidentVice President

November 20, 2009November 20, 2009

Numeric Nutrient RulesNumeric Nutrient Rules Numeric Nutrient Rules Born From EPA Numeric Nutrient Rules Born From EPA

Requirement (Requirement (National Strategy for the National Strategy for the Development of Regional Nutrient CriteriaDevelopment of Regional Nutrient Criteria, June , June 1998)1998) 22ndnd Highest Cause of Impairments in 305(b) Lists Highest Cause of Impairments in 305(b) Lists Nutrient Over-enrichment in Gulf of MexicoNutrient Over-enrichment in Gulf of Mexico

For Those States With Narrative Nutrient Rules, For Those States With Narrative Nutrient Rules, Adopt State Numerical Rules or Use EPA’s Adopt State Numerical Rules or Use EPA’s Numbers (In Guidance Documents)Numbers (In Guidance Documents)

State’s PrioritiesState’s Priorities 11stst: Lakes and Streams (Met 23 Times): Lakes and Streams (Met 23 Times) 22ndnd: Estuaries (Met 1 Time June 5/6, 2008): Estuaries (Met 1 Time June 5/6, 2008) 33rdrd: Wetlands (No Meetings Yet): Wetlands (No Meetings Yet)

Numeric Nutrient Rule Technical Numeric Nutrient Rule Technical Advisory Committee (TAC)Advisory Committee (TAC)

Started in 2002Started in 2002 Membership Representation:Membership Representation:

CountiesCounties Private River/Lake ExpertsPrivate River/Lake Experts Estuarine ExpertsEstuarine Experts Cross-over TAC Member *Cross-over TAC Member * UniversitiesUniversities EPA Region IVEPA Region IV Lake O ExpertsLake O Experts Water Management DistrictsWater Management Districts Environmental InterestsEnvironmental Interests

Met 24 Times (Including 2 Public Meetings)Met 24 Times (Including 2 Public Meetings)

* Member from Impaired Waters Rule TAC

For more information:http://www.dep.state.fl.us/water/wqssp/nutrients/

Current Florida Narrative Current Florida Narrative Nutrient StandardsNutrient Standards

Chapter 62-302-530(48)

“(b) In no case shall nutrient concentration of a body of water be altered so as to cause an imbalance in natural populations of aquatic flora and fauna.” [Classes I, II & III]

Complications:What does “imbalance” mean?What is the difference between “natural population” and “population resulting from natural conditions”? Or are they the same?

EPA’s Original Approach From EPA’s Original Approach From GuidanceGuidance

Based on EPA River/Stream, Lake, Estuary Based on EPA River/Stream, Lake, Estuary and Wetland Guidance Documentsand Wetland Guidance Documents

Uses Level III Ecoregions and All Nutrient Uses Level III Ecoregions and All Nutrient monitoring data in STORET (Note: 1/3monitoring data in STORET (Note: 1/3rdrd of all of all nutrient data in EPA’s STORET is from nutrient data in EPA’s STORET is from Florida)Florida)

http://www.epa.gov/waterscience/criteria/nutrient/guidance/

Note: It is likely that EPA will use more updated numbers and techniques in future work – these are the only numbers they have published.

IXSoutheastern Plain

XIISouthern Coastal Plain

XIII Southern Florida

Coastal Plain

Based on 25th Percentile of All STORET Nutrient Data

for Ecoregions

IX – Panhandle

XII – Central

XIII – South FL

Selection of Approach If State Promulgates Selection of Approach If State Promulgates Numerical RuleNumerical Rule

EPA Said To Consider:EPA Said To Consider:

Causal Variables – Nitrogen Causal Variables – Nitrogen & Phosphorus& Phosphorus

Response Variables – Response Variables – Chlorophyll “a” & TurbidityChlorophyll “a” & Turbidity

Preferred “Cause – Effect” Preferred “Cause – Effect” ApproachApproach

Dose-Response Like ToxicsDose-Response Like Toxics

NO IMPACT

OutlierLargemouthbass

ACUTE

CHRONIC

0 1 2 3 4 5 6 7 8 9

DISSOLVED OXYGEN [ mg/L ]

0

2

4

6

8

10

OPTIMAL

GROWTHRETARDATION

LETHAL

Reference Site Approach 2Reference Site Approach 2ndnd Choice Choice

Chose Reference SitesChose Reference Sites

Characterize Nutrient Concentrations at These Sites Characterize Nutrient Concentrations at These Sites Nutrient Criteria Nutrient Criteria

Consideration of Nutrient RulesConsideration of Nutrient Rules

Springs and Spring RunsSprings and Spring Runs LakesLakes Streams, Rivers and CanalsStreams, Rivers and Canals

Change Point at 0.441 mg/L Nitrate-nitrite, R2 = 0.62

Suwannee Periphytometer Change Suwannee Periphytometer Change Point Analysis: Cell DensityPoint Analysis: Cell Density

Mean NOx (Mg/L)

Me

an

Ce

ll D

en

sity

(/S

qu

are

-CM

)

0.0 0.2 0.4 0.6 0.8

02

*10

^56

*10

^51

0^6

Clear statistical point at which increase in cell density with increase in nitrate plus nitrite nitrogen.

Nitrate-nitrite ConclusionsNitrate-nitrite Conclusions Lab studies demonstrated nitrate-nitrite was Lab studies demonstrated nitrate-nitrite was

primary factor causing elevated growth at primary factor causing elevated growth at levels above 0.230 to 0.263 mg/llevels above 0.230 to 0.263 mg/l

Independent field studies showed imbalances Independent field studies showed imbalances occur at 0.441 to 0.454 mg/l nitrate-nitrateoccur at 0.441 to 0.454 mg/l nitrate-nitrate

Proposed criterion combines both lines of Proposed criterion combines both lines of evidence = 0.35 mg/levidence = 0.35 mg/l

Also applied to clear streams (<40 PCU)Also applied to clear streams (<40 PCU)

PCU = Platinum Cobalt Units

LakesLakes

Draft Nutrient Criteria for Lakes based on Draft Nutrient Criteria for Lakes based on “dose-response” analysis: TN and TP to “dose-response” analysis: TN and TP to Chlorophyll Chlorophyll aa

Chlorophyll Chlorophyll aa Targets Targets Colored Lakes (>40 PCU) = 20 µg/lColored Lakes (>40 PCU) = 20 µg/l Clear Lakes (<40 PCU)Clear Lakes (<40 PCU)

– High Alkalinity (≥ 50 CaCOHigh Alkalinity (≥ 50 CaCO33) = 20 µg/l) = 20 µg/l

– Low Alkalinity (< 50 CaCOLow Alkalinity (< 50 CaCO33) = 9 µg/l) = 9 µg/l

PCU = Platinum Cobalt Units

Colored Lake Chlorophyll Chlorophyll aa Response to Total Phosphorus

Annual Geometric Mean TP (mg/L)

0.01 0.1 1

Ann

ual G

eom

etri

c M

ean

Chl

-a (

µg/

L)

1

10

100Ln (y) = 1.128 Ln(x) + 5.729

R² = 0.581

Regression Line

50% Prediction Interval

Chl-a typically > 20Chl-a typically < 20

Range of Uncertainty

0.05 0.157

Proposed Lakes Criteria

Measured as Annual Geometric MeanMeasured as Annual Geometric Mean Below Lower Threshold then UnimpairedBelow Lower Threshold then Unimpaired In Between, Check Chlorophyll In Between, Check Chlorophyll aa

Stressor →

Lake Type

Response -

Chla (µg/ l)

Lower

Threshold

Upper

Threshold

Lower

Threshold

Upper

Threshold

Colored 20 1.23 2.25 0.050 0.157

Clear - High Alkalinity 20 1.00 1.81 0.030 0.087

Clear - Low Alkalinity 9 0.85 1.14 0.015 0.043

TN (mg/ l) TP (mg/ l)

Streams, Rivers and CanalsStreams, Rivers and Canals

State attempted “dose-response” analysis State attempted “dose-response” analysis without meaningful results, includingwithout meaningful results, including Chlorophyll Chlorophyll aa Taxonomic composition of macroinvertebratesTaxonomic composition of macroinvertebrates Algal communities (frequency & occurrence)Algal communities (frequency & occurrence)

EPA Recommended Next Choice – Reference EPA Recommended Next Choice – Reference Stream ApproachStream Approach

Note: By “without meaningful results” I mean statistical correlations explained a very small percentage of data variation.

Benchmark Benchmark Nutrient RegionsNutrient Regions

Used 90Used 90thth Percentile Percentile of Data from of Data from

Reference LakesReference Lakes

Rivers & Streams

Parameter

Pan-

handle

North-

east

North

Central Peninsula

Bone

Valley

South

Florida

TP (mg/ l) 0.069 0.101 0.322 0.116 0.415 ?TN (mg/ l) 0.82 1.73 1.73 1.73 1.73 ?

FDEP Draft

Nutrient Region

Comparison of ResultsComparison of Results

Rivers & Streams

Parameter

Pan-

handle Central South

Pan-

handle

North-

east

North

Central Peninsula

Bone

Valley

South

Florida

TP (mg/ l) 0.04 0.04 0.069 0.101 0.322 0.116 0.415 ?TN (mg/ l) 0.69 0.90 0.82 1.73 1.73 1.73 1.73 ?Chla (µg/ l) 0.93 0.40

Turbidity (NTU) 7.02 1.90

Lakes

Parameter

Pan-

handle Central South

Lower

>50

CaCO2

Higher

>50

CaCO2

Lower

≤50

CaCO2

Higher

≤50

CaCO2 Lower Higher

TP (mg/ l) 0.020 0.010 0.018 0.030 0.087 0.015 0.043 0.050 0.157

TN (mg/ l) 0.36 0.52 1.27 1.00 1.81 0.85 1.14 1.23 2.25

Chla (µg/ l) 5.2 2.6 3.4 20.0 20.0 9.0 9.0 20.0 20.0

Secchi (meters) 1.53 2.10 0.79 ↑ ↑ ↑

If Chla OK, then Criteria = Measured Ambient below Higher.

Ecoregion Colored (> 40 PCU)

Ecoregion

EPA Guidance

EPA Guidance FDEP Draft

Clear (< 40 PCU)

FDEP Draft

Nutrient Region

Issues – Rules & EnforcementIssues – Rules & Enforcement Draft FDEP Rule:Draft FDEP Rule:

FDEP and EPA approved TMDLs would be listed in FDEP and EPA approved TMDLs would be listed in draft rule as potential Site Specific Alternative draft rule as potential Site Specific Alternative CriteriaCriteria

EPA to review each approved TMDL as change in EPA to review each approved TMDL as change in WQ criteriaWQ criteria

EPA Indicated That Each Parameter Would Be EPA Indicated That Each Parameter Would Be Independently Applied (e.g., for a TN-limited Independently Applied (e.g., for a TN-limited Lake, if Chlorophyll A and TN are less than Lake, if Chlorophyll A and TN are less than criteria and TP is above, the Lake would be criteria and TP is above, the Lake would be impaired)impaired)

Issues – Implementation PolicyIssues – Implementation Policy

WWTP WWTP AWT Results in 3 mg/l TN & 1 mg/l TPAWT Results in 3 mg/l TN & 1 mg/l TP WW Reuse Wet Weather DischargeWW Reuse Wet Weather Discharge Discharge from Artificial WetlandsDischarge from Artificial Wetlands

New Draft Florida Stormwater Rule – New Draft Florida Stormwater Rule – Undeveloped Lands EMCs are 1.15 mg/l TN and Undeveloped Lands EMCs are 1.15 mg/l TN and 0.055 mg/l TP0.055 mg/l TP

How The Criteria Are Going To Be Used Is Just How The Criteria Are Going To Be Used Is Just As Important As NumbersAs Important As Numbers

Recent EventsRecent Events

EPA Washington settled (signed by EPA Washington settled (signed by EPA on August 19EPA on August 19thth) with ) with Environmental Plaintiffs on Numerical Environmental Plaintiffs on Numerical Nutrient Criteria (NNC)Nutrient Criteria (NNC)

EPA will issue NNC for Florida by EPA will issue NNC for Florida by January 14, 2010 for lakes and January 14, 2010 for lakes and streams and by January 14, 2011 for streams and by January 14, 2011 for estuariesestuaries

My OpinionMy Opinion Scientific Justification for:Scientific Justification for:

Springs and Spring Runs (Clear Streams)Springs and Spring Runs (Clear Streams) LakesLakes

Limited or No Justification for Streams and Rivers:Limited or No Justification for Streams and Rivers: Relationships Between Nutrients and Biological Relationships Between Nutrients and Biological

Balance Not Found Even Though Florida Has Large Balance Not Found Even Though Florida Has Large Ambient Nutrient DatabaseAmbient Nutrient Database

Reference Streams Based on Unaffected Conditions Reference Streams Based on Unaffected Conditions Not Lack of Impairment (i.e., Biological Imbalance)Not Lack of Impairment (i.e., Biological Imbalance)

Merit in Numerical Nutrient Criteria for Spring Runs, Merit in Numerical Nutrient Criteria for Spring Runs, Lakes and EstuariesLakes and Estuaries

My RecommendationMy Recommendation Set Nutrient Targets Based on Protection Set Nutrient Targets Based on Protection

and Restoration of Lakes and Estuariesand Restoration of Lakes and Estuaries Set Nutrients in Stream or River:Set Nutrients in Stream or River:

Based on TMDL-like Analysis To Protect Based on TMDL-like Analysis To Protect Downstream Lake or Estuary Downstream Lake or Estuary

If Biological Impairment is Measured in the If Biological Impairment is Measured in the Stream or River, Set Site Specific Nutrient Stream or River, Set Site Specific Nutrient Targets Only if There is a Strong Relationship Targets Only if There is a Strong Relationship Between Biological Impairment and Nutrient Between Biological Impairment and Nutrient InputsInputs

Thank You! Questions?Thank You! Questions?