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East / West Spring Lake Wastewater Expansion Pilot Program

East / West Spring Lake Wastewater Expansion Pilot Program. Workshop – Water Quality Review July 1, 2013. PRESENTATION OUTLINE. Purpose Regulations OSTDS Evaluation – East & West Spring lake Sampling & Test Results Other Contributors Soils Data Relevant Studies Summary. Purpose.

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East / West Spring Lake Wastewater Expansion Pilot Program

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  1. East / West Spring Lake Wastewater Expansion Pilot Program Workshop – Water Quality Review July 1, 2013

  2. PRESENTATION OUTLINE • Purpose • Regulations • OSTDS Evaluation – East & West Spring lake • Sampling & Test Results • Other Contributors • Soils Data • Relevant Studies • Summary

  3. Purpose • Provide a summary of Water Quality Data collected within the East & West Spring Lake Area • Provide a summary of similar studies • Provide a summary of Regulations • Provide a correlation with Onsite Sewage Treatment and Disposal Systems (OSTDS)

  4. Regulations • 62E-06, Florida Administrative Code • OSTDS Regulations • 62-302, Florida Administrative Code • Numeric Nutrient Criteria • Manchester Lock Permit

  5. 62E-6 OSTDS REGULATIONS • Provides requirements for OSTDS construction & repair • 1983 standards changed • Separation from seasonal high water table Increased from 12-inches to 24-inches • Setback from water body Increased from 50-feet to 75-feet* • Septic tank and drainfield sizes increased • Sizes dependent on structure size * Charlotte Code of Ordinances (3-7-56) restricts setback to 150-feet for tidally influenced water bodies

  6. 62E-06 REGULATIONS CONT’D • 1983 standards changed • Separation from seasonal high water table Increased from 12-inches to 24-inches • Setback from water body Increased from 50-feet to 75-feet* • Septic tank and drainfield sizes increased • Sizes dependent on structure size * Charlotte Code of Ordinances (3-7-56) restricts setback to 150-feet for tidally influenced water bodies

  7. 62E-06 REPAIR REQUIREMENTS Conventional Septic System

  8. 62E-06 REPAIR REQUIREMENTS CONT’D

  9. 62E-06 REPAIR REQUIREMENTS CONT’D

  10. 62-302 NUMERIC NUTRIENTS • Set nutrient loading limitations for estuaries • Arithmetic mean shall not to be exceeded more than once in a 3-year period

  11. Manchester Lock Permit • FDEP Permit 08-0210682-001 • “A Phased Sewer Expansion – include in the Charlotte County Sewer Expansion Plan those portions of the Alligator Bay Drainage Basin that have been shown to contribute to declining water quality (pre-1983 septic tanks)”

  12. OSTDS EVALUATIONS • 1,708 recorded OSTDS’s in East/West Spring Lake • 452 vacant lots • Buildout percentage = 80% • 1,286 OSTDS (75.3%) installed prior to 1983

  13. OSTDS EVALUATIONS CONT’D

  14. OSTDS EVALUATIONS CONT’D • Water level data was collected in East/West Spring Lake to determine water table relative to ground surface • To meet 24-inches of separation for current regulations, the seasonal high water table should not be within 3.5 feet of ground surface or below land surface (BLS)

  15. OSTDS EVALUATIONS CONT’D Groundwater Elevations in East & West Spring Lake * Based on mean water levels, it is estimated that the majority of the systems do not meet current or past separation requirements and some drainfields may be within the water table a portion of the year.

  16. OSTDS EVALUATIONS CONT’D • Ordinance 2007-061: Management of OSTDS • Since adoption (2007 to Present), 250 repairs have been made in East & West Spring Lake • Prior to adoption (1950s to 2007), 132 repairs had been made • When a failure occurs, regulations require OSTDS to meet current standards. If separation from seasonal high water table cannot be met, the replacement system must be elevated (mounded)

  17. Mound System Impacts • More expensive • More maintenance / pump failure • Affects aesthetics • Difficult to maintain grounds • Limits use of property • Drainage problems • Special construction needs: • Dosing chamber • Pump • Retention/landscape wall

  18. Mound System Aerial View

  19. SAMPLING & TEST RESULTS • 50+ wells installed throughout East & West Spring Lake • 21 canal sample points within & upstream of East & West Spring Lake • Wells sampled and tested every 2 months • Nitrogen • Phosphorous • Fecal Coliform • Water levels

  20. NITROGEN RESULTS Nitrogen Concentrations in East & West Spring Lake Nitrogen Concentrations in Canal System

  21. PHOSPHOROUS RESULTS Phosphorous Concentrations in East & West Spring Lake Phosphorous Concentrations in Canal System

  22. FECAL COLIFORM RESULTS Fecal Coliform Concentrations in East & West Spring Lake Fecal Coliform Concentrations in Canal System

  23. SUMMARY OF RESULTS • Nitrogen • Range: 0.004 mg/L to 39.17 mg/L • Drinking water limit: 10 mg/L • NNC limit: 0.67 mg/L • Wells closest to OSTDS had highest recordings • Groundwater levels > canal levels • Levels highest winter season when winter residents are present

  24. SUMMARY OF RESULTS CONT’D • Phosphorous • Range: 0.02 mg/L to 31.69 mg/L • NNC limit: 0.19 mg/L • In wells, 150 of 171 samples tested higher than the NNC limit (88%) • In canals, 55 of 69 samples tested higher than NNC limit (80%) • The average for all samples was 0.895 mg/L, 5 x the NNC limit • Wells closest to OSTDS had highest average recordings • Groundwater levels > canal levels • Levels highest in winter season when winter residents are present

  25. SUMMARY OF RESULTS CONT’D • Fecal Coliform • Range: 10 col/100 ml to 2940 col/100 ml • Multiple samples tested above 400 col/100, two (2) from the same well • Canal levels > groundwater Levels • Levels highest during wet Season when soils are saturated & filtration & adsorption is reduced due to high water table

  26. OTHER CONTRIBUTORS • Atmospheric • Deposition of nutrients from atmosphere • Fertilizer • Can result in application of nitrogen & phosphorous • Restricted use (Ordinance 2011-017) • No phosphorous application June 1 to September 30 • < 4 lbs of nitrogen can be applied / yr / 1,000 sf • < 0.5 lbs of phosphorous can be applied / yr / 1,000 sf • Other (Animals, etc.)

  27. OTHER CONTRIBUTORS CONT’D • Difference between OSTDS and other contributors • Nutrients from other contributors are applied in the atmosphere and are largely taken in by plant life • Nutrients from OSTDS are released below the ground and depend on soils for removal prior to entering groundwater

  28. SOIL CLASSIFICATIONS • Matlacha Sands • Kesson Fine Sand • Pineda Fine Sand • Oldsmar Fine Sand • Common traits of soils in E/W Spring Lake • Gravelly fine sand • Poorly drained • Unsuitable for drainfields • Seasonal high water table within 10-inches BLS • Kesson, noted as being located in tidal swamps subject to tidal flooding

  29. RELEVANT STUDIES • Charlotte Harbor & Estero Bay Aquatic Preserves Water Quality Status & Trends for 1998-2005 • Study reviewed water quality data within regions of Charlotte Harbor & Estero Bay • Upper Charlotte Harbor results • Highest phosphorous levels of region • Highest single nitrogen recording • 70th Percentile of Florida estuaries for Phosphorous • 80th Percentile of Florida estuaries for Nitrogen • 80th Percentile of Florida estuaries for Fecal Coliform

  30. RELEVANT STUDIES CONT’D • Effects of Seasonal Variability on Microbial Fecal Pollution and Enteric Pathogens in a Subtropical Estuary • 12 sample stations were set within Charlotte Harbor and sampled monthly for indicator bacteria • 4 of the stations were located in the vicinity of East & West Spring Lake (East Spring Lake, West Spring Lake, Sunrise Waterway & Countryman Waterway) • Of the samples tested, East & West Spring Lakes recorded the highest & 2ndhighest fecal levels • Concentrations were highest during wet season

  31. RELEVANT STUDIES CONT’D • Groundwater System Water Quality Data Port Charlotte Area • Study performed for the purpose of characterizing surface & groundwater quality in Port Charlotte • 8 study sites selected within a 400 home area • Monitoring wells installed to determine direction of groundwater flow and plume potential for nutrients from OSTDS to edge of lot lines • Average nitrogen levels of 21.62 mg/L at drainfield and 7.92mg/L at lot line • Average phosphorous levels of 26.43 mg/L at drainfield and 14.80 at Lot Line

  32. SUMMARY & CONCLUSIONS • Several factors reviewed link OSTDS’s to decreased water quality in East/West Spring Lake: • Soils unsuitable for OSTDS installation • A seasonal high water table unsupportive of treatment • A population density unfavorable for OSTDS • Close proximity to canals • Limited treatment capability of OSTDS • Test results indicating positive correlation with nutrients & bacteria • Studies indicating high nutrient & fecal levels in upper Charlotte Harbor, amongst the highest in the State

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