Wayne Magley FDEP Division of Environmental Assessment and Restoration

### Geographical and Physical Description  Located on northern east coast of Florida  Lower St. Johns River extends from mouth of Ocklawaha River to Atlantic Ocean (about 101 miles)  Water surface area of 115 square miles  A sixth
- order, darkwater river estuary, and, along its length, it exhibits characteristics associated with riverine, lake, and estuarine aquatic environments  Tidal influence ranging from 0.35 to 5.49 ft depending upon location  A low gradient (averages 0.1 ft/mile) elongated riverine
- estuary system  Average depth of less than 3 mo Low-head, lacustrine, humid/sub
tropical blackwater river estuary of the southeastern U.S. o Mean discharge 235 m 3/sec o Southern- most natal river for eastcoast anadromous fish o Large tide range (1.5 m) propagated 200 km upstream o Tidal flow >> Net Discharge o Tidemarsh habitat o Significance: o Major SE U.S. port o 2 large military bases o Important commercial and recreational fisheries o Significant cultural and aesthetic resource (American Heritage River)

## Geographical and Physical Description
 Four ecological zones, based on salinity  There is a shift in land use from wetland, open land and agriculture in the southern portion of the basin to a highly urbanized area (Jacksonville/Duval County) in the meso
polyhaline zone

## Waterbody Identification

Numbers for the Main Stem of the LSJR

## Fresh Tidal Water Quality Time Series Example

## Fresh Tidal Water Quality Time Series Example

## Oligohaline Zone Water Quality Time Series Example

## Oligohaline Zone Water Quality Time Series Example

## Meso- Polyhaline Zone Water Quality Time Series Example

## Meso- Polyhaline Zone Water Quality Time Series Example 

### Springs and Ground water : There are 18 springs within the LSJR Basin, 9 of the springs are considered magnitude 3 springs (discharge 1

– 10 cfs . Morris (1995) reported that the USGS estimated the net upward leakage from ground water into the river of 82 cfs for WY 1990 (a relatively dry year) and about 127 cfs under more normal conditions.  

### Wastewater: Within the LSJR Basin 112 facilities are authorized to discharge to surface waters under an NPDES permit. The nutrient TMDL and BMAP for the LSJR provided allocations for 36 facilities (32 domestic wastewater facilities and 4 industrial wastewater facilities) that discharged directly into the Lower St. Johns or below the head of tide to tributaries that discharged into the river. 

## Atmospheric Deposition: Pollman and Roy (2003) estimated a total annual flux of wet and dry inorganic nitrogen of 4.67 to 6.82 kgN/ha, with an average value of 6.12 kgN/ha. The annual average wet deposition of total phosphorus over the 1994

– 1999 period was estimated to range between 4.5 and 12.4 kgP/km 2 

## , with an average of 8.25 kgP/km 2



## .  

## Nonpoint Source Discharges : Stormwater from urban and rural areas. Twelve major tributary watersheds have been identified as contributing flow to the Lower St. Johns River. 

## Low Dissolved Oxygen: Periods of low DO observed in meso
- polyhaline zone based on continuous monitoring since 1995. Typically during the July

– September period.  

## Chlorophyll a : Concentrations in fresh tidal zone exceed 20 ug/L, during blooms, values over 60 ug/L.  

## Nuisance or toxic algal blooms: Periodic occurrences of nuisance and toxic algae blooms during the summer. Seven known or potentially toxic or harmful algal species have been identified in the LSJR.

###  Fish Kills: Periodic fish kills have been observed in both the fresh water and marine portions of the LSJR, especially during summer periods.  Reduced Clarity: Color levels are elevated and water clarity is reduced during periods of increased fresh water discharges from upstream and tributaries.

### Nuisance and Harmful Algal Blooms in the St. Johns River Estuary: Mechanisms of Development and Species of Concern
 Flow determines dinoflagellate or bluegreen dominance  Most likely to exhibit HAB species, particularly Microcystis aeruginosa Oligohaline Reach Marine Reach and Atlantic Inner Shelf  Integrates shelf and oligohaline environments  Occasional contain HAB species Karenia brevis (red tide) & Pseudo-nitzschia

Fresh Tidal Reach  Highest density of SJRE, dominated by cyanobacteria  Density positively correlated with residence time  Significant water quality problems 

### Verified list of Impairments for the Cycle 1 Assessment for the Lower St. Johns River Basin (adopted in May 2004) included 28 waterbodies for nutrients. Sixteen listings for DO were associated with elevated algal biomass or linked to nutrients based on median TN and/or TP concentrations. There were 6 predominantly marine WBIDs listed for nutrients.  

### Verified list of Impairments for the Cycle 2 Assessment (adopted in May 2009 and amended in January 2010) included 29 listings for nutrients. Eighteen listings for DO were associated with elevated algal biomass or linked to nutrients based on median TN and/or TP concentrations. There was 1 predominantly marine WBID listed for nutrients and none listed for DO

###  

## In August 2008, FDEP re -adopted the nutrient TMDL for the Lower St. Johns River.  

## Allowable annual loads for TN and TP were assigned to the fresh water portion (fresh tidal zone) based upon the pollutant load reduction goal (PLRG) developed by the SJRWMD.  

## Allowable annual loads for TN were assigned to the marine portion (oligohaline and meso
polyhaline zones) based on the PLRG.**Lower St. Johns Water Quality Model Grid, Watersheds and**  **Point Sources ( )** 

### TMDL Tools: • Quasi
- dynamic version of the classic spreadsheet land use loading model for NPS

- Being upgraded to assess ERP urban development • Adaptation of CE
- QUAL
- ICM (Chesapeake Bay Eutrophication Model) to the LSJR

- Expanded through L. George and 2005 • Specific monitoring and investigations related to chemistry, plankton, nutrient limitation, atmospheric deposition, and sediment flux. 

### Linking Degree of Effects to the Biological Community: St
. Johns R. Estuary Eutrophication Models• Chlorophyll
- a > 40 μg/L generally recognized as nuisance condition

• Corresponds to FL TSI = 70

• Established criteria (North Carolina, Lake Okeechobee)

• In LSJR :

– Community composition above 40 μg/L is > 80% cyanobacteria

– Chlorophyll
- a > 40 μg/L for > 40 days associated declines in “good” zooplankton

– In nutrient enrichment assays, the incidence of high microcystin concentration increased when chlorophyll
- a exceeded 40 μg/L 

### LSJR Fresh Tidal Criteria

0 0.2 0.4 0.6 0.8

1

0 50 100 150 200Cyanobact Biovol / Total Biovol

Chl -a ug/L Cyano Dominance vs Chl (Apr
-Oct)

LG Pal Racy

# LSJR Marine Reach **Dissolved Oxygen** August 1999

# LSJR Dissolved Oxygen SSAC

• Based on the EPA Ambient Aquatic Saltwater Criteria (Virginian Province; EPA

822 -R-00- 012)

• Designed to protect against effects from long

term (days to weeks) low D.O.

• Limits low D.O. exposure to no more that 5% loss of most sensitive species MAX CHRONIC IMPAIRMENT
YEAR ACOSTA DAMES 1996 0.03 0.25* 1997 0.37 1.74 1998 0.73 0.56 1999 0.10 3.57 2000 0.26 0.20 2001 0.19 1.07

### Lower St. Johns Proposed Numeric Nutrient Criteria  The Department proposes to adopt the annual TMDL nutrient loads for the marine portion of the LSJR as load based numeric nutrient criteria that would apply to the marine portion of the LSJR (see Table).  And adopt the annual TMDL TN and TP loads for the freshwater portion of the river as downstream protection values that will protect the LSJR estuary. The Chla target of 40 ug/L not to be exceeded more than 10% of the time is proposed as a numeric nutrient target applicable to the tidal freshwater portion of the LSJR as a long
-term average. Freshwater WBIDs Parameter TMDL (kg/yr) 2213I to 2213N Total Nitrogen 8,571,563 2213I to 2213N Total Phosphorus 500,325 Marine WBIDs Parameter TMDL (kg/yr) 2213A to 2213H Total Nitrogen 1,376,855

# Waterbody Identification

Numbers for the Main Stem of the LSJR

## Numeric Nutrient Criteria Considerations  Criteria include magnitude, frequency, and duration components.  Expressed as loads, concentrations, or both?  The document presents some initial work on approaches to developing numeric concentrations.  How should the criteria be assessed in the future?  Interested in public input! 

### Acknowledgements  John Hendrickson and Dr. Peter Suscy at the SJRWMD were responsible for the main work that constitutes the scientific basis for the Total Maximum Daily Load.  Dr. Edward Phlips from the Department of Fisheries and Aquatic Sciences at the University of Florida for sharing his research on phytoplankton dynamics and work to support numeric nutrient criteria. Link: http://www.dep.state.fl.us/water/wqssp/nutrients/estuarine.htm