1. Nutrient Issues at the Blue Plains WWTP February 2004

2. Blue Plains Snapshot –Flow  Design Annual Average: 16.2 m 3 /s (370 mgd)  Peak: 43.8 m 3 /s (1 bgd) –Effluent Limits  NH 3 :1.0 mg/l (May 1 to Oct 30) 6.5 mg/l (Nov 1 to April 30  TP: 0.18 mg/l  BOD5/TSS: 5/7 mg/l

3. Aerated Grit FeCl 3 Primary Sediment FeSO 4 Secondary AS Nitrification Filtration Dechlorination Potomac River Chlorination Chlorine Process Flow Diagram Pumping

4. Blue Plains Nitrogen Control Efforts Goal: Reduce controllable loads of nutrients including nitrogen by 40% from the 1985 levels by the year 2000, and maintain those levels into the future Status: Nitrogen loads from Blue Plains declined by 7 million pounds per year from 1995 to 2003. The load was reduced by 49%, surpassing the Chesapeake Bay goal. This significant reduction was achieved through the use of Biological Nutrient Removal (BNR) Technology.

5. Denitrification Process Selection u Lowest cost alternative for nitrogen removal - 1990 study –Bench testing showed promise –Low capital cost offsets operating costs u Process considered experimental - especially at this scale - Conduct pilot

6. Denitrification Process Selection u Use excess capacity available in nitrification process u Conduct full plant study u Monitor results on both sides. u TN Goal 7.5 mg/L yearly average: –Winter: 8.58 mg/l –Summer: 5.55 mg/l

7. Nitrification Facilities RAS Reactors Lime To Multimedia Sedimentation Basins WAS Secondary Effluent

8. Denitrification Process RAS Reactors Lime To Multimedia Sedimentation Basins WAS Secondary Effluent Methanol

9. IMA Shares at Blue Plains

10. u Meeting Maryland and/or Virginia’s load allocations would require: –Additional treatment for a portion of the flow, as needed (Blended Effluent) –Significant capital expenditures u Meeting ALL BP users’ needs – under a regulatory program -- would require: –Plant-wide facilities upgrade –Major capital expenditures u Costs will depend on the level of nutrient reduction (Tier) that will be needed Nutrient Reduction Options @ Blue Plains

11. Voluntary Program Estimated Costs (*) All WWTPs at their year 2000 levels (#) Blue Plains is at 7.5 mg/lit TN & 0.18 mg/lit TP; budget is for facilities needed to accommodate new digester effluent [$] Under NPDES permit requirement, the cost would be 30- 50% higher Nutrient Reduction Options at Blue Plains TierTN mg/litTP mg/litLife Time Budget I8.00(*)$0 II (#)8.001.00$30,000,000 III5.001.00$349,000,000 IV3.000.50$466,000,000 Total (cumulative) [$]$845,000,000

12. Other Capital Costs Facing DCWASA u Ongoing 10 year Capital program –$1.8 billion –Infrastructure/plant rehabilitation –Technology enhancements supporting operational efficiencies u Proposed CSO Long-Term Control Plan –$1.265 billion over 15-25 years –Enhancement of water quality in tributaries of Chesapeake Bay, notably Anacostia River u Lead Service Replacement Issues u Emerging regulatory/security issues

13. WASA’s CURRENT POSTURE u Meet all regulatory requirements u Continue strong support of state-by- state determination of methods to meet “caps” u Provide services to jurisdictions to assist in meeting their nutrient goals within Blue Plains capacity u Emphasize that DC’s primary appeal for federal assistance will be directed to the Anacostia CSO issue u Continue strong support of a VOLUNTARY (non-Regulatory) Nutrient Reduction Program