1. Occoquan and Dulles Policies Potomac DWSP Partnership Meeting February 21, 2008

2. An Overview of: The Occoquan Policy The Occoquan Policy Occoquan Watershed Monitoring Laboratory (OWML) Occoquan Watershed Monitoring Laboratory (OWML) Occoquan Non-Point Source Program Occoquan Non-Point Source Program Dulles Policy Dulles Policy

3. Special Water Quality Standards in Virginia

4. Reservoirs and Service Areas

5. Watershed Facts Area: 592 Square Miles Area: 592 Square Miles Streams: 1,300 Miles Streams: 1,300 Miles Major impoundments: Major impoundments: – Lake Manassas – Lake Jackson – Occoquan Reservoir Land Use (estimate): Land Use (estimate): –14% Low Density Residential –8% Medium and High Density Residential –4% Commercial and Industrial –1% Institutional –13% Agricultural –9% Pasture –51% Forest and Idle Residents: 390,000 (estimate) Residents: 390,000 (estimate) Source: OWML -1998, NVRC - 2000, 2005

6. The Problem Late 1960s – WQ problems in the Occoquan Reservoir: Late 1960s – WQ problems in the Occoquan Reservoir: –Massive algal blooms –Periodic episodes of taste and odors in drinking water –Shortened filter runs due to clogging during periods of high algal growth –Periodic fish kills due to oxygen depletion –Hypolimnetic de-oxygenation due to accumulation of organic material in the sediments The State Water Control Board (Board) commissioned a Study to recommend a course of action to preserve the Occoquan as a valuable water resource for future generations. The State Water Control Board (Board) commissioned a Study to recommend a course of action to preserve the Occoquan as a valuable water resource for future generations. The Study results stated that point source pollution was the primary cause of water quality degradation The Study results stated that point source pollution was the primary cause of water quality degradation A high degree of waste treatment would be necessary to prolong the life of the drinking water supply. A high degree of waste treatment would be necessary to prolong the life of the drinking water supply.

7. Summer 1973 – Algal Bloom (Source: OWML)

8. The Policy 1 Formed UOSA (Upper Occoquan Sewage Authority) to Consolidate Older WWTPs Formed UOSA (Upper Occoquan Sewage Authority) to Consolidate Older WWTPs Established Occoquan Watershed Monitoring Program Established Occoquan Watershed Monitoring Program Established Indirect Potable Reuse as Sustainable Water Supply for Northern Virginia Established Indirect Potable Reuse as Sustainable Water Supply for Northern Virginia Regulation administered by Virginia Department of Environmental Quality (VDEQ) Regulation administered by Virginia Department of Environmental Quality (VDEQ) 1 A Policy for Waste Treatment and Water Quality Management in the Occoquan Watershed

9. Policy Requirements – WWTP Plants Preferably only two high-performance regional plants Preferably only two high-performance regional plants All point sources preferably 20 stream miles from Fairfax Water intake All point sources preferably 20 stream miles from Fairfax Water intake Incremental increases in regional plant capacity must be approved based on results of the monitoring program Incremental increases in regional plant capacity must be approved based on results of the monitoring program All future plants must meet or exceed UOSA design standards All future plants must meet or exceed UOSA design standards

10. Policy Requirement - Effluent Discharge Limits: Discharge Limits: –COD (mg/l) - 10.0 –Suspended solids (mg/l) - 1.0 –Nitrogen (mg/l) - 1.0 (as TKN) –Phosphorus (mg/l) - 0.1 –MBAS (mg/l) - 0.1 –Turbidity (NTU) - 0.5 –Coliform per 100 ml Sample - less than 2.0

11. UOSA Process Treatment (from OWML)

12. Policy Requirement – Wastewater Operation All pumping stations in the watershed must have: –Stand-by pumping units –At least one “on-site” back-up power supply –At least one “off-site” back-up power supply –Be designed so that no single failure of a mechanical or electrical component could degrade pumping capability –Have pumps and valves arranges so that these units can be removed and replaced without by-pass pumping –Have retention basins of minimum one-day capacity –Have flow measurement devices Nitrate removal required when NOx conc. Reach 5 mg/l at Intake Nitrate removal required when NOx conc. Reach 5 mg/l at Intake

13. Policy Requirement – Collection Systems Certified and submitted to Board – Inflow/Infiltration (I/I) limited to 100 gal/inch- dia/mile/day Certified and submitted to Board – Inflow/Infiltration (I/I) limited to 100 gal/inch- dia/mile/day Approved pre-treatment program Approved pre-treatment program Up-to-date and maintained (subject to annual inspection) electrical and fluid system diagrams Up-to-date and maintained (subject to annual inspection) electrical and fluid system diagrams Detailed as-built and installed drawings Detailed as-built and installed drawings

14. Occoquan Watershed Monitoring Program Occoquan Watershed Monitoring Lab (OWML) Occoquan Watershed Monitoring Lab (OWML) –Sampling and Analysis –Stream Gages and Reservoir Stations Overseen by Occoquan Watershed Monitoring Subcommittee Overseen by Occoquan Watershed Monitoring Subcommittee Objective: to Ensure that performance levels are maintained and that the effects of point and non-point sources are known Objective: to Ensure that performance levels are maintained and that the effects of point and non-point sources are known

15. Occoquan NPS Programs Technical Investigations and Support Technical Investigations and Support –Northern Virginia BMP Handbook –Nonstructural Urban BMP Handbook –Land Use Inventory and Updates Fairfax County Water Supply Overlay District Fairfax County Water Supply Overlay District Historic Fairfax County Down-zoning to Protect Occoquan Reservoir Historic Fairfax County Down-zoning to Protect Occoquan Reservoir Occoquan NPS Model Occoquan NPS Model

16. Summary Occoquan Policy was a milestone in Water Quality Management in the Commonwealth of Virginia Occoquan Policy was a milestone in Water Quality Management in the Commonwealth of Virginia Water Quality improved dramatically after UOSA came on-line Water Quality improved dramatically after UOSA came on-line Reservoir Water Quality has remained stable for decades Reservoir Water Quality has remained stable for decades

17. Special Water Quality Standards in Virginia SWCB Adopts in 1971 (revised 1981 and 1991) UOSA on-line in 1978 SWCB Adopts in 1975 (revised in 2004) LCSA Broad Run WRF on-line soon

18. Evolution of Dulles Policy Wastewater issues of 1970s Wastewater issues of 1970s Adopted by SWCB in 1975 as a ‘planning’ document for regional sewage treatment in northwestern Fairfax and eastern Loudoun Counties Adopted by SWCB in 1975 as a ‘planning’ document for regional sewage treatment in northwestern Fairfax and eastern Loudoun Counties Policy revised in 2004 to update for new LCSA Water Reclamation facility Policy revised in 2004 to update for new LCSA Water Reclamation facility

19. Dulles Policy – Regional Plants Limits Regional Plants to 2 Limits Regional Plants to 2 Discharge in the Broad Run and Goose Creek Watersheds Discharge in the Broad Run and Goose Creek Watersheds No discharges within 10 stream miles upstream from Water Supply Intakes No discharges within 10 stream miles upstream from Water Supply Intakes High-performance effluent requirements based on Occoquan Policy High-performance effluent requirements based on Occoquan Policy Nitrate removal required when NOx conc. reach 5 mg/l at Intake Nitrate removal required when NOx conc. reach 5 mg/l at Intake LCSA and Fairfax Water to coordinate monitoring program LCSA and Fairfax Water to coordinate monitoring program

20. Collaborative Updates (2000-2004) DAWP Stakeholder Meetings: FW, LCSA, Fairfax Co., VDEQ, OWML, VDH, NVRC, City of Leesburg DAWP Stakeholder Meetings: FW, LCSA, Fairfax Co., VDEQ, OWML, VDH, NVRC, City of Leesburg Craft reasonable and protective Policy modifications Craft reasonable and protective Policy modifications Objective: Ensure Protection of FW Intake Objective: Ensure Protection of FW Intake

21. Dulles Policy Revisions (2004) Effluent Quality Limits for COD, TKN, TP, Turbidity, Coliform (now E.Coli limit), and TSS – same as Occoquan Policy Effluent Quality Limits for COD, TKN, TP, Turbidity, Coliform (now E.Coli limit), and TSS – same as Occoquan Policy Collaborative process was successful Collaborative process was successful

22. Questions?