Water Resources Technical Committee

1
Water Resources Technical Committee

• Chesapeake Bay Program
• Overview Updates
• July 10, 2008
• Tanya T. Spano

2
OVERVIEW

• CBP General Objectives Timeline
• Bay Models Updates Applications
• 2030 Land Use Model
• Impairments Nutrient/Sediment Loads
• 303(d) List of Impaired Waters
• Load Allocations
• Bay TMDL(s)
• 2030 Land User Model Projections

3
CBP General Objectives Timeline

• Principles
• Shared Urgency to Restore the Bay
• Clear Communication Common Message
• Focus Accelerate Implementation
• Engage the Public About the Implementation
  Process
• Legal Obligations Will Be Met
• Improving Applying the Latest Science
• Flexibility of Sub-allocations within the Major
  Basins
• Keep Healthy Waters Healthy
• Finalize Bay TMDL - by May 2011

4
Bay TMDL Help Implementation?

• Strengthens legal defense of NPDES limits
• Provides stability for allocations
• Provides opportunity for needed adjustments in
  2003 allocations
• Direct public dialogue to promote implementation

5
Nutrient/Sediment Allocation Processes

• 2003 Process
• NP caps to meet tributary CB4 segment
• Decision Rules
• Equitable distributions to tributaries states
• Left sub-allocation decisions Tributary
  Strategy implementation up to states
• Bay TMDL Process
• Reflect model updates/new data
• Need to reflect/integrate sediment loads/impacts
• Regulatory requirements limit discretion
• Desire to preserve flexibility/trading promote
  implementation
• Is a UAA required?

6
Bay TMDL Schedule

• Define Required Load Caps - 2008
• For Bay
• For Tidal Tributaries
• For Nitrogen, Phosphorus Sediment
• To achieve attainment based on latest 303(d)
  lists
• Evaluate various management scenarios
• Climate Change 2030 impacts Will Consider
• Determine if need to adjust cap and/or
  allocations
• Assess if a Bay UAA is required
• Agree on State/Tributary Allocations 2009
• Sub-Allocations to Sources 2009-2010
• Public Participation Now through 2011
• Issue Final Bay TMDL May 2011

7
Bay Models Updates Applications

• Models
• Airshed
• Sediment Sheds
• Watershed Model
• Water Quality Model
• Hydrodynamic
• Living Resources
• Updates/New Data
• Model elements/functions
• Input data
• BMP efficiencies
• Land use / land cover
• 2030 Land Use Model
• Derived from WSM other growth/projection
  models
• TMDL Allocation Applications
• WSM - STAC comments versus MDs intentions
• WQM All Forested Baseline, Factor of Safety,
  Averaging Period Concerns

8
Impairments Nutrient/Sediment Loads

• 303(d) List of Impaired Waters
• All derived from agreed upon Bay-specific water
  quality criteria and Designated Uses
• For all tidal states (including DE)
• DC EPA approval expected July 2008
• MD EPA approval expected August 2008
• CB4 How to Address less than 100 attainment
  under a TMDL?
• VA EPA approval expected September 2008

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Impairments Nutrient/Sediment Loads

• Load Allocations
• Changes Required from 2003?
• UAA Needed?
• Decision Rules
• State Allocations vs. sub-allocations to sources
• Bay TMDL(s)
• Margins of Safety explicit vs. implicit
• Baseline All Forested Scenario
• Regulatory Requirements for NPDES Permits WWTP
  vs. MS4
• Decisions will set precedence for EPA for a major
  TMDL
• Links to Tributary Strategies?
• Accelerate implementation?

10
2030 Land User Model Projections

• CBP issued preliminary county-level
  landuse/population projections
• COG staff provided COG region population data
• Population projections from states
• Developed current/future septic sewered data
• Ad Hoc Technical Steering Committee
• Paul DesJardin, Tanya Spano, Norm Goulet
• COG staff working with members to compare/verify
  against existing data future projections
• Concerns raised with WWTP projections BMP/land
  use concerns

11
2030 Land User Model Projections

• Next Steps
• Continue to review current data with COG
  members/agencies
• Evaluate against other existing projections
• Work through Ad Hoc SC to address critical
  regional issues/resolve major discrepancies
• Implement Hybrid approach for WTTP projections
• Suggest hybrid approach to CBP
• Use most accurate information available from COG
  and its members
• Use CBP calculations/logic where accurate
  information does not exist
• Provide formal comments Summer/Fall 2008

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WASTEWATER FLOW PROJECTIONSPreliminary
Comparisons
13
WASTEWATER FLOW PROJECTIONSPreliminary
Comparisons
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Wrap-Up

• Information Questions?
• Discuss Technical Policy Issues after
  presentations
• Consider various COG staff recommendations