y Project - Navigating NNC

Transcription

1 Paynes Prairie Sheetflow Restoration y Project - Navigating NNC g Stranded Up p the Creek Without Getting Rick Hutton, P.E., Gainesville Regional Utilities FWEA Utility Council July 11,

2 Project Location 2

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5 Historical Impacts 1800s to present: Urbanization of Gainesville Stormwater runoff Trash T h & sediment di t WW Effluent Septic Tanks 1930s:Sweetwater Branch channeled directly to Alachua Sink 1,300 acres of wetlands impacted. Direct flow path from Gainesville to Alachua Sink

6 Alachua Sink Total Maximum Daily Load (TMDL) Alachua Sink Impaired for Nitrogen & Chlorophyll a (Chla (Chla)) 2006 Alachua Sink TMDL 55% N reduction in Point Sources 45% N reduction in Non Non--Point Sources 6

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9 Paynes Prairie Sheetflow Project Partners FDEP St. Johns River Water Management District Florida Department of Transportation US EPA Alachua County Florida Fish and Wildlife Conservation Commission

10 Compliance with NNC Alachua Sink 2006 TMDL adopted by FDEP & approved by EPA as site site-specific criteria Project P j t Meets M t TMDL, TMDL & th therefore f meets t NNC ffor Alachua Al h Sink Sweetwater Branch 1.3 mi Section downstream of MSWRF Currently No TMDL for TN or TP Nutrients not affecting biology Biologically impaired due to high runoff flows Highly channelization & Incised 10

11 Alternatives to Comply p y w/ NNC for Sweetwater Branch A. Meet Threshold Criteria (TN 1.87 mg/l, TP 0.30 mg/l) Build $8M Pipeline to Bypass Sweetwater Branch B. Alternatives for Seeking Site Specific Criteria 1 Exclusion from stream criteria, 1. criteria due to physical alteration 2. Reclassification 3. Level II WQBEL 11

12 Alternatives to Comply with NNC for Sweetwater Branch 1. Exclusion from Stream Criteria Highly in habitat Hi hl altered lt d & low l ini -stream t h bit t scores, BUT riparian i i habitat scores high resulting in overall Stream Habitat Assessment above threshold 12

13 Alternatives to Comply with NNC for Sweetwater Branch 2. Reclassification to Class III Limited & SSAC Concern over lack C l k off local l l support 13

14 Level II WQBEL Approach Q pp 1. Data Collection 2. Stressor Identification Study 3 Modeling of Future Conditions 3. 14

15 1. Data Collection Physical Data Hydrologic H d l i Data D Stream Habitat Assessment Bi l i l Data Biological D Benthic Invertebrates Vegetation Survey Algae & Periphyton Surveys Nutrients & Water Quality Experimental high plant flow test 15

16 2. Stressor Identification Studyy Use data to demonstrate that the cause of impairment is not nutrients: 1. Biological health no different up up-- & downstream of MSWRF 2. Cause of impairment not due to nutrients No adverse floral impacts p due to nutrients Faunal impairment due to other factors 3. Data from other sites 4. Probable cause of impairment 16

17 3. Modeling g of Future Conditons Use QUAL2K model to predict what will happen in future f t when h MSWRF iis att buildout b ild t flow: fl nutrient concentrations other water quality parameters Algae and Periphyton Verify f stream & downstream wetlands not adversely impacted the future when the MSWRF is at full buildout flows Demonstrate proposed site specific nutrient criteria are protective 17

18 Current Status Most of data already collected WQBEL Study St d Plan Pl U Under d Development D l t

19 Questions?