1. Rock Creek Sewer Separation & Water Main Replacement – CSO 031, 037, 053 and 058 Presented to CWEA / WWOA / CSAWWA 2011 Tri-Association Conference Collections Systems August 31, 2011 Wednesday – 1:30pm District of Columbia Water and Sewer Authority

2. CSO LTCP – Consent Decree DEADLINES!!! Award Design Contract March 23, 2007 Award Construction Contract March 23, 2009 Complete Separation March 23, 2011 2

3. CD Project Requirements DC Water needs to separate the areas tributary to CSOs 031, 037, 053 and 058 in order to eliminate them as CSO outfalls. 3 Foggy Bottom DuPont Circle Georgetown National Zoo Woodley Park CSO 031 CSO 037 CSO 053 PROJECT LOCATIONS CSO 058

4. 4 CSO 031 - Overview Smallest sewershed to separate – approx 2 acres Comprises one building (mixed use) Work located south of Pennsylvania Ave, NW on NPS property Requires 160 ft of 10 sanitary sewer installation M Street Pennsylvania Avenue 26 th Street Rock Creek & Potomac Parkway L Street

5. 5 CSO 037 - Overview Sewershed approx 15 acres 57 Private Properties (Residential / Embassy) In DDOT (Public) ROW: 3500 ± feet of new sewers (san & storm) 3600 ± feet of water main replacement 1800 ± feet of sewer rehabilitation (san) NPS Property: 600 ± feet of sewers installed via trenchless methods Rock Creek & Potomac Parkway Massachusetts Avenue 24 th Street Kalorama Road

6. 6 CSO 053 - Overview Sewershed approx 10 acres 10 Buildings in Project Site (6 res., 4 large multi-unit) In DDOT (Public) ROW: 675 ± feet of new sewers (san & storm) 875 ± feet of water main replacement NPS Property: 825 ± feet of new sewers (Portions installed via trenchless methods) Q Street Rock Creek & Potomac Parkway P Street

7. 7 CSO 058 - Overview Approx 22 acres remaining to separate in the sewershed (DC PWD separated the other 83 acres in the 1960s) Approx 30 Buildings in Project Site (Residential / Commercial) Public ROW: 1000 ± feet of sewer installation (san & storm) 1200 ± feet of sewer rehabilitation (sanitary) 2000 ± feet of water main replacement NPS Property: 1100 ± feet of sewer installation (250 ± feet via trenchless methods ) Calvert Street Rock Creek & Potomac Parkway Connecticut Avenue

8. Separation Planning Challenges Major Traffic Routes Affected Environmental Assessment Required DC Water has NO easements on Federal (NPS) and District property Voluntary private property separation Embassies required State Department Involvement 8

9. Separation Design Challenges Avoid / Minimize Disturbances to – bridges, historical sites, major traffic routes, building driveways & access, NPS property, existing utilities, Metro stops, embassy events... 9

10. Project Statistics Engineers Estimate-$13,166,273.00 Contract bid value -$10,992,563.00 Anticipated Completion Cost -$12,000,000.00 Notice to Proceed - Mar. 25, 2009 Contract Milestone - Jan. 24, 2011 EPA Consent Decree Date -Mar. 23, 2011 (Sewer Separation Complete) Project Completion Date -Nov. 20, 2011

11. Stakeholders U.S. State Department Embassies/Consulates National Park Service DDOT Mosque Residents Business Owners/Restaurants Apartments/Senior Housing ANCs/Ward Friends of Rock Creek (FORC) DDOE (now an MS4 area)

12. Permits District (Dept. of Consumer Regulatory Affairs – DCRA) Public Space Permits Traffic Control & After Hours (DDOT) Stormwater Mgmt / S & E Control (DDOE) Federal (National Park Service – NPS) Environmental Assessment Archaelogical / Historical Wetland / Floodplain Etc. Special Use Permit Others

13. Major Construction Issues Kalorama Road Electric duct conflict Belmont Road NPS land – Unanticipated rock

14. Kalorama Road – Storm Sewer Electric Duct Bank – 350 foot conflict Limited space for rerouting due to other utilities Limited corridors for relocating due to major electric crossing/vault Time constraints Cost Issues

15. Kalorama Road

16. View of Electric Vault

17. Kalorama Road View of Tunneling Shield

18. Kalorama Road Tunnel Face with Rock

19. Kalorama Road Hand Mining

20. Kalorama Road From Tunnel Looking South

21. Belmont Road/NPS - Rock Time to complete first bore Additional 2 bores with rock at launch pit Steep slopes NPS land subject to no surface disturbance Locating rock surface profile Determining proper equipment Time constraints Successful Bores

22. Proposed Seismic Alignment

23. Velocity Profile

24. Proposed Vertical Alignment

25. Belmont Road Looking Uphill (South)

26. Belmont Road Equipment Setup

27. Belmont Road Equipment Setup

28. Belmont Road Equipment Setup

29. Belmont Road Tunneling

30. Belmont Road Tunneling

31. Belmont Road Tunnel Face

32. Lessons Learned Start Early! Take care of all the stakeholders Additional upfront utility locates Subsurface Exploration Partnering with Contractor Flexibility in Construction