Floridas Statewide Stormwater Treatment Rule: Integrating Land and Water Management to Promote Susta

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Floridas Statewide Stormwater Treatment Rule
Integrating Land and Water Management to Promote
Sustainable Resources

• FDEP, Jennifer Nelson
• Presenting for Eric Livingston and Michael Bateman

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Stormwater Impacts From Urbanization

• Changes in
• Ground water infiltration
• Watershed hydrology
• Stream hydrology
• Stream morphology
• Riparian Zone habitat
• Water quality
• Aquatic habitat
• Aquatic ecosystems

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Impaired Waters Problems and Pollution Sources

• Major Pollutants of Concern
• Nutrients, nutrients, nutrients!
• Oxygen demanding substances
• Bacteria
• Major Sources of Pollutants
• Stormwater existing development
• Stormwater future development
• Stormwater agricultural
• Leaching agriculture, landscape, OSTDS

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Estero Bay TMDL Update

• TMDLs Established
• Hendry Creek (Fresh)
• Total Nitrogen (DO)
• Hendry Creek (Marine)
• Total Nitrogen (DO)
• Fecal coliform
• Imperial River
• Total Nitrogen (DO)
• Fecal coliform

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The Solution?Statewide Stormwater Treatment Rule

• POST PRE
• Peak Discharge Rate
• Volume
• Recharge
• Pollutant Loading (nutrients)

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The Path Forward to Increased Nutrient Treatment

• BMP Research, development, demos
• Revised erosion/sediment BMPs
• Evaluation of current criteria
• Low Impact Design Land Development
  Regulations/Manuals
• Low Impact Design workshops
• Stormwater TAC
• Stormwater rule development/workshops
• Rule/BMP training workshops

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Statewide Stormwater Rule

• The Unified Rule will provide a standard process
  to ensure appropriate Environmental Resource
  Permitting (ERP) criteria are used for stormwater
  runoff from new developments
• Science has shown improvements are needed

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Evaluation of Current Stormwater Design Criteria
within Florida Harper Study (2007)

• Objectives
• Review current BMP design criteria of DEP/WMDs
• Update Florida stormwater EMC data
• Estimate predevelopment hydrology and stormwater
  loadings
• Update Florida BMP treatment effectiveness data
• Model BMP treatment effectiveness
• Evaluate BMP design criteria changes needed to
  achieve 80, 95, no net increase in nutrients

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Major Findings

• Rainfall more highly variable than previously
  thought
• EMCs are updated
• Runoff coefficients more variable than previously
  thought loadings more variable
• Current rules do not provide for 80 to 95
  removal of nutrients
• Infiltration BMPs can meet higher levels but will
  have to retain more runoff
• BMP treatment train/reuse needed for wet ponds to
  meet higher levels of nutrient removal

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Major Findings Treatment Levels

• Confirmed that on-site stormwater treatment can
  be greatly improved.
• Current rules do not achieve 80 nutrient
  treatment
• Performance Standard will be post-development
  nutrient load pre-development nutrient load
  (based on natural land)
• Current rules are inconsistent between regions
  and result in inefficient, complicated, and
  costly compliance.
• New development is exacerbating the existing
  nutrient transport problem.

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Rule Recognizes Limits of Structural BMPs

• Limited nutrient treatment capabilities
• Lack of flexibility in site design
• Loss of useable land area
• Connection of impervious areas
• Disregard site resource benefits
• Altered site hydrology/pollutant loads
• Cost
• Maintenance obligations

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Preventing Stormwater Pollution Nonstructural
BMPs

• Land Use Management Promote LID
• Protect natural SWM areas, wetlands, riparian
  buffers
• Minimize vegetation clearing and soil compaction
• Minimize impervious surfaces
• Cluster Development
• Source Controls
• Florida Friendly Landscaping
• Green Industry BMP program (landscape companies)
• Fertilizer BMPs and regional practices
• Public Education
• Storm sewer stenciling
• Roof runoff to pervious areas
• Aquascaping littoral areas

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Unified Stormwater Rule Concepts

• One storm does not fit all
• BMP treatment train required
• Credits for nonstructural BMPs
• Green roofs / cistern systems
• Preserving vegetation / minimize clearing
• Pervious concrete
• Florida Friendly Landscaping
• Disconnect impervious areas
• Higher CN for cleared areas (compaction)
• Compensating treatment (WQ Banking)
• Retrofit section
• Reuse water will play an important role

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BMP Treatment Train Required for Wet Detention
Areas Recommended for all Sites

• Alum
• Reuse
• Regional
• Ponds
• Wetlands

• Source Controls
• Public Ed
• Protect Vegetation
• Limit Clearing
• Erosion Control
• Roof Runoff
• FYN
• LID

• Green Roofs
• Swales
• Landscaping
• Catch Basins
• Filter Inlets
• Baffle Boxes
• Biodetention

• Sediment Basins
• Retention
• Detention
• Wetlands

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Unified Stormwater Rule Proposed Methodology

• Proposed Treatment Standard PostPre Loading for
  TP TN
• Presumption that other pollutants will be treated
  sufficiently
• Site specific assessment required
• Assumed predevelopment conditions
• Calculate pre-development nutrient loads
• Calculate post-development nutrient loads
• Determine level of treatment required
• Develop BMP Treatment Train to achieve required
  load reductions

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Why a New Stormwater Rule?

• Too many polluted waterbodies!
• Too many nutrients!
• Promote Green Growth Integrating
  nonstructural BMPs
• Consistency A level playing field
• Simply time to evolve BMPs dynamic
• Regain our 1 Status!!

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Additional Information available from

• FDEP
• Eric Livingston, Bureau of Watershed Management
• Eric.livingston_at_dep.state.fl.us 850/245-8430
• Michael Bateman,
• Betsy Hewitt
• SFWMD
• Damon Meiers, Deputy Department Director,
  Environmental Resource Regulation Department,
  dmeiers_at_sfwmd.gov. 1-800-432-2045, ext. 6876 or
  [phone]