Water Resources Technical Committee

Chesapeake Bay ProgramOverview & Updates

July 10, 2008Tanya T. Spano

9/13/07 WRTC Business Meeting 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

9/13/07 WRTC Business Meeting 3

CBP – General Objectives & Timeline

Principles:1. Shared Urgency to Restore the Bay2. Clear Communication & Common Message3. Focus & Accelerate Implementation4. Engage the Public About the Implementation

Process5. Legal Obligations Will Be Met6. Improving & Applying the Latest Science7. Flexibility of Sub-allocations within the Major

Basins8. Keep Healthy Waters Healthy

Finalize Bay TMDL - by May 2011

9/13/07 WRTC Business Meeting 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

9/13/07 WRTC Business Meeting 5

Nutrient/Sediment Allocation Processes

2003 Process N&P 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?

9/13/07 WRTC Business Meeting 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

9/13/07 WRTC Business Meeting 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 MD’s intentions WQM – All Forested Baseline, Factor of Safety, & Averaging

Period Concerns

9/13/07 WRTC Business Meeting 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

9/13/07 WRTC Business Meeting 9

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?

9/13/07 WRTC Business Meeting 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

9/13/07 WRTC Business Meeting 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

9/13/07 WRTC Business Meeting 12

WASTEWATER FLOW PROJECTIONSPreliminary Comparisons

Jurisdiction 2010 2020 2030

CBP COG % Diff

CBP COG % Diff

CBP COG % Diff

Prince George’s County

91.47 111.42 22 97.70 122.67 26 100.82 133.28 32

Montgomery County

97.17 105.21 8 103.59 116.22 12 108.56 125.62 16

District of Columbia

61.93 167.06 170 69.04 179.41 160 74.46 187.33 152

9/13/07 WRTC Business Meeting 13

WASTEWATER FLOW PROJECTIONSPreliminary Comparisons

Jurisdiction 2010 2020 2030

CBP COG % Diff CBP COG % Diff

CBP COG % Diff

Fairfax County

121.69 131.54 8 137.14 148.23 8 143.02 155.98 9

Loudoun County

27.87 22.88 -18 37.98 32.17 -15 42.97 37.54 -13

9/13/07 WRTC Business Meeting 14

Wrap-Up

Information Questions?

Discuss Technical & Policy Issues after presentations

Consider various COG staff recommendations