1. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two1 Lake Tahoe TMDL Phase Two Fall 2007 Public Participation Series Source Category Group Focus Team Meetings

2. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two2 TMDL Program Overview A science-based plan to restore Lake Tahoe’s clarity

3. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two3 Central TMDL Questions Questions Addressed 1.What pollutants are causing Lake Tahoe’s clarity loss? 2.How much of each pollutant is reaching Lake Tahoe? 3.How much of each pollutant can Lake Tahoe accept and still achieve the clarity goal? Current Questions 1.What are the options for reducing pollutant inputs to Lake Tahoe? 2.What strategy should we implement to reduce pollutant inputs to Lake Tahoe?

4. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two4 Source Category Group Analysis Opportunities Basin-Wide load reduction estimates Relative load reduction opportunity among source categories Consistent methods to evaluate future pollutant control options

5. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two5 Source Category Group Analysis Boundaries Not suited to project scale Evaluated pollutant control options chosen for data availability Limited time, resources, and effectiveness data

6. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two6 Continuous Improvement Adaptive management process SNPLMA science funding opportunities Each group identified “next steps” and data needs

7. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two7 Focus Team Role Gain technical understanding of SCG approach Act as a liaison to your agency Provide input on preferred pollutant control options Suggestions for future work

8. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two8 Questions?

9. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two9 Questions Addressed What is causing Lake Tahoe’s clarity loss? Suspended fine sediment Floating algae – fed by nutrients Very fine sediment (<20 microns) accounts for ~2/3 of the clarity conditions

10. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two10 How much of each pollutant is reaching Lake Tahoe?

11. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two11 How much of each pollutant is reaching Lake Tahoe?

12. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two12 How much of each pollutant is reaching Lake Tahoe?

13. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two13 How much of each pollutant can Lake Tahoe accept and still achieve the clarity goal? The Lake Clarity Model provides estimates of clarity response to load reductions Reducing fines has a greater potential to improve clarity Model output indicates significant reductions will be needed

14. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two14 What are the options for reducing pollutant inputs to Lake Tahoe? Good Question!

15. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two15 Approach to Answering Current Questions Identify load reduction options Quantify load reduction options Prepare Integrated Strategies Gather stakeholder input

16. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two16 Pollutant Load Reduction Opportunity Project - People Source Category Groups Technical Reviewers Source Category Integration Committee Project Team Focus Teams

17. PCO Concepts Screening Process Viable PCOs PCO Grouping Process Treatment Tiers A A B C A B C Settings Extrapolation Process GIS Models Step 1: PCO Evaluation Step 2: Site-Scale Analysis Step 3: Basin-Wide Analysis Nitrogen Reduction Table Sediment Reduction Table Phosphorus Reduction Table Tier 1 Tier 2 Tier 3 Load Tables Cost Tables Combined Results Tables Total 20 Year Cost Table Capital Cost Table O & M Cost Table Cost- Effectiveness Table PCO Concepts Screening Process

18. PCO Concepts Screening Process Viable PCOs PCO Grouping Process Treatment Tiers A A B C A B C Settings Extrapolation Process GIS Models Step 1: PCO Evaluation Step 2: Site-Scale Analysis Step 3: Basin-Wide Analysis Nitrogen Reduction Table Sediment Reduction Table Phosphorus Reduction Table Tier 1 Tier 2 Tier 3 Load Tables Cost Tables Combined Results Tables Total 20 Year Cost Table Capital Cost Table O & M Cost Table Cost- Effectiveness Table PCO Concepts Screening Process

19. PCO Concepts Screening Process Viable PCOs PCO Grouping Process Treatment Tiers A A B C A B C Settings Extrapolation Process GIS Models Step 1: PCO Evaluation Step 2: Site-Scale Analysis Step 3: Basin-Wide Analysis Nitrogen Reduction Table Sediment Reduction Table Phosphorus Reduction Table Tier 1 Tier 2 Tier 3 Load Tables Cost Tables Combined Results Tables Total 20 Year Cost Table Capital Cost Table O & M Cost Table Cost- Effectiveness Table PCO Concepts Screening Process

20. Sept. 10 and 11, 2007Lake Tahoe TMDL - Phase Two20 Development Summary PCO Selection and Evaluation Site Scale Analysis –Settings –Tiers Basin-wide extrapolation