1. Ross By-Pass Tunnel Cleanup Pre-Bid Project Overview May 2014
Ross Dam
Pre-Bid
Project Overview May 2014
Project Location
This presentation is for general info. Consult the RFP for details.
Skagit River

2. City Light Admin Offices
Diablo Boat house
Ross Dam
City Light Admin Offices

3. Getting to the work site
Diablo
Boathouse
Diablo dam
Highway 20
To Ross dam
Diablo Dam and boat house

4. Project Location: Ross Hollow Jet Valve House
Dam
Valve house
Hollow Jet
Valves
Opening to
Tunnel
Diablo Lake /
Skagit River

5. Problem
Past O&M work (sandblasting) left lead in the sediment in the tunnel.
Can’t pump tunnel dry without discharging lead into Diablo Lake
Goal
Remove lead to allow future O&M work to pump tunnel dry when needed for inspections and repairs

6. Plan view By-pass intake structure Ross Lake Diablo Lake
Tunnel and two
By-pass penstocks
Hollow Jet Valves &
Valve House

7. Bypass Penstock Tunnel
Diablo Lake
Ross Dam
Valve house
Typical water Level (1205) 9 8 6 4 3 2 1 7 5 10
Concrete
Tunnel plug
Hollow Jet
Valves
By-pass
penstock
Tunnel
Sump
Pipe
saddles

8. Cross Section of Pipe Supports
Penstocks
Concrete
wall
Tunnel
Doorway
Not to scale

9. Inside
Valve House
Tunnel & By-pass
penstocks

10. Scope of work Install temporary weir (vendor) or permanent weir (SCL)
Install rock fall fence (vendor)
Remove and treat 1,000,000 gallons of water from tunnel to remove suspended lead (vendor)
Remove 10 – 30 cy sediment (vendor)
Verify & Dispose sediment – could be dangerous waste (SCL)

11. 1. Opening to tunnel Lake level can fluctuate 4-5 feet daily.
~8-ft
Higher lake level (elev 1205)
~5-ft
Lower lake level (elev 1199)
Lake level can fluctuate 4-5 feet daily.
The lake may have waves.

12. 1. Install weir Weir Isolate tunnel from fluctuating lake levels
Protect workers
Keep debris out of tunnel
Contractor can use SCL weir or build their own temporary weir
Proposed SCL metal weir (install in June or October depending on Contractor’s preference)

13. 2. Rock fall Protection (vendor)
Temporary fence

14. 3A. Mobilize Valve House Spill way Temp rock fence SCL Barge Ross Dam

15. Vendor Submittals (pre-mobilization)
Health & Safety Plan
Hazardous waste handling plan
Work plan
Contact info
Water Tectonics Electro-coagulation operation manual
Schedule
Spill control plan
Barge loading & operation plan *
Temporary weir *
Rock fall fence
Equipment and materials
* Need engineer stamp

16. Vendor Mobilization Load water treatment equipment on barge
Provide generator, pumps, worker shack, sani-can, ladders, lights, etc.
* Some size restrictions: tunnels, barge load, barge access, etc.

17. 3B. De-water Tunnel Pump out clean water & direct discharge to lake
Pump out dirty* water and treat prior to discharge Approximately 750,000 – 1,000,000 gallons
Water is ~12 – 16-ft deep
*Dirty = > 5 NTU turbidity

18. 3C. Water Treatment on Barge
Discharge to Diablo Lake
pump
Tunnel
shack
Sand filter
Back flush tank
Settling tank #2
Settling tank #1
Source tank
Electro coagulation
Sani can
generator
80T Barge
Not to scale
Water Tectonics is the MANDATORY SUB-CONTRACTOR
Must use Electro-Coagulation Treatment System

19. 4. Remove Sediment Workers enter all ten chambers
Remove sediment (dredge? Pressure wash? Sweep?)
Dirty water and sediment pass through treatment
Sediment collects in tanks

20. 5A. Verification Clean water is discharged
Batch testing 1 – 3 times
Weekly water discharge samples
Sub-contractor operations
Chambers are clean and lead free
Visual inspection
Water samples

21. 5B. Waste disposal Vendor will: SCL will: Unload tanks from barge
Transfer sediment to waste containers
Dispose of other debris (trash, sani-can, misc. debris)
SCL will:
Test for dangerous waste
Haul lead-contaminated sediment and sand filter media to proper disposal site

22. Misc. Vendor tasks Collect samples & deliver to lab
Provide crew boat to shuttle staff
Provide lodging for crews
Reporting to SCL and Ecology
Site cleanup (non-hazardous materials)
Demobilization

23. Vendor Selection

24. Mandatory Pre-bid meeting
At SKAGIT – meet at Newhalem General Store
RSVP
Bring Hard Hat & Lock Out Tag Out locks
Read and be ready to sign SCL LOTO policy
If you don’t bring LOTO locks, you will be left behind at the General Store.

25. Vendor selection Requirements Pre-qualifications Worked off barge
Attend mandatory pre-bid Skagit site visit
- Will use Water Tectonics as sub
- Can obtain insurance in a timely manner
Pre-qualifications
Worked off barge
Removed underwater sediment
Handled contaminated material

26. Vendor selection (cont.)
50% price
50% approach – submit 4 page document
Work plan
Safety
Environment
Experience
FYI: Prevailing wages apply

27. Tunnel Cleanup Schedule
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Permits
Procure-ment
Submittal
Tunnel Cleanup

28. Payment Pay Activity 5% Submittals and Mobilization 10%
20%
25%
40%
Activity
Submittals and Mobilization
Water Treatment System running
5 chambers clean
All chambers clean
Finish, cleanup, demob
Stand by
Incentive for finishing early: $1,000/day