CASE STUDY: Renovation of a Fully-deteriorated Trunk Sewer at a Large U.S. Brewery

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1 CASE STUDY: Renovation of a Fully-deteriorated Trunk Sewer at a Large U.S. Brewery Evanco Environmental Technologies Inc. Kyle Verwey and Randy Cooper TRENCHLESS TECHNOLOGY ROADSHOW May 28-29, 2014 Scotiabank Convention Centre, Niagara Falls, ON

2 AGENDA Project Overview Condition Assessment and Risks Bypass Design Development and Challenges Cured-In-Place Pipe Lining Manhole Rehabilitation Challenges and Lessons Learned Conclusions and Summary

3 Project Overview Primary process waste trunk sewer for a large U.S. Brewery was found to be fully deteriorated Approximately 1 mile of 36-inch diameter pipe comprised of Vitrified Clay, Ductile Iron, and Reinforced Concrete 21 deteriorated concrete manholes, including 3 large vaults, and 2 drop structures Process sewer flows directly beside a fresh water canal, which supplies over 300,000 local people with drinking water Numerous segments of pipe found unstable with limited access

4 System Overview MH 16 MH 15 MH 18 MH 20 MH 21 MH 19 PWTP N Fresh Water Canal MH 11 MH 12 MH 14 MH 13 MH 17 MH 10 MH 8 MH 9 MH 7 MH 6A 6 APTP MH 4A MH 4 MH 3A MH 3 MH 2A* *Manhole to be installed

5 Condition Assessment Sewer was initially identified as significantly deteriorated in 2011 when a backhoe driving over the pipeline collapsed the pipeline at the most downstream end of the sewer This collapse initiated an inspection of the entire length of the sewer Significant corrosion was identified beginning from the Anaerobic Pre-Treatment Plant (APTP) and continuing downstream

6 Condition Assessment - Pipelines Significant pipe obvert corrosion (above flowline) Colonization of pipe crowns by Thiobacillus bacteria caused by high concentrations of H 2 S gas

7 Corrosion Failure Mechanism APTP generates high concentration of hydrogen sulfide (H2S) in downstream sewer pipes and manholes. Airborne Thiobacillus bacteria attaches to pipe crowns and multiplies. Bacteria oxidizes H2S (consumes sulfur), producing sulfuric acid (H2SO4) above flow line Sulfuric acid corrodes both concrete (RCP) and ductile iron (DI) pipe crowns weakening and eventually collapsing pipes at crowns.

8 Risk of Pipeline Instability Very High Large sections of pipe obverts were missing Soil arching only mechanism keeping the pipe intact

9 Condition Assessment Unmapped Pipeline Obstruction Added Risk Concrete sanitary sewer (neighbouring City Trunk!) found crossing process sewer at right angles (red arrow). Concrete pipe corroded and obstructing 50% of sectional process flow area. Design change needed to stabilize pipe and accommodate structural rehabilitation with CIPP.

10 Condition Assessment - Manholes Heavy corrosion noticed from the surface (frames and covers) heavy H2S odours Some covers had been locally repaired to maintain stability (red arrow)

11 Condition Assessment - Manholes Heavy corrosion of concrete shafts and surface slabs Manhole 3A (below) concrete top slab had corroded from 9 to less than 4

12 Other Assessed Risks Process sewer buried beneath a large embankment for 2500, directly beside a fresh water canal This embankment also has: High Pressure Natural Gas lines, 24 Sanitary Sewer, Sludge Force Mains, Manholes and Poison Ivy

13 Bypass Design Development - Challenges Single bypass designed for full project duration (one header, with back-up pumps) No available access point - a new pump manhole was to be created Depth of the sewer and the elevation of site (mountains) forced pumps to be set below grade Access point had buried obstructions including a 18 process force main and a 10 water main with only 9 between Trench Box with 8 Spreaders 10 Water Main 18 Process Force Main

14 6x 8 Hydraulic Pumps New MH 2A Fundamental Bypass Design Layout 4 Duty 8 pumps operating with 3000 GPM output (each) 2 pumps on standby 1 Duty 8 pump operating with 3000 GPM output 1 pump on standby x 18 SDR 17 HDPE Header Cellar 12 Bypass IC Reactor 2x CD225 8 Pump 8 SDR 17 HDPE Header CD150 6 Pump Bar Screen Building 10 SDR 17 HDPE Header PA/Equalization Tank

15 Bypass Development and Challenges While excavating for bypass access, lean concrete was encountered By breaking through 10 of concrete the trunk sewer pipe was accessed

16 Bypass Development and Challenges The 36 process sewer was completely encased in concrete with no mention on any plant drawing 3 weeks of 24-hr operations to expose the pipe (red arrow)

17 Bypass Development and Challenges Schedule change pushed Evanco into winter lining operations, at high elevations, in the foothills of a mountain range

18 Bypass Development and Challenges After excavating concrete and soil, a sump was constructed adjacent to the 36 process sewer to support the pump around bypass The process pipe was side-cut (live) to create suction sump in very tight quarters

19 Bypass Development and Challenges Hydraulic submersible pumps were used to protect man entry as well as manage very tight space limitations Flow was stopped using pneumatic sewer plugs, and 24/7 bypass was established

20 Pipeline Bypass Challenges Pipeline Collapse During bypass development and concrete cutting work, heavy, cold rain events added more delays Heavy rains precipitated downstream pipe failure close to the site of previous 2011 collapse 2011 Patch Repair Concrete New 36 OD RCP Pipe has a wall thickness of 3.5

21 Pipeline Bypass Challenges Pipeline Repair Evanco quickly repaired the collapse with HDPE, and backfilled with concrete surround to facilitate lining.

22 CURED-IN-PLACE PIPE LINING Winter Weather Once bypass was established; cleaning, inspecting, and lining began Embankment roadway could not support heavy lining equipment Crane mats were installed to support lining equipment loads Fresh Water Canal

23 Cured in Place Pipe Lining Design: ASTM F1216-7a

24 CURED-IN-PLACE PIPE LINING Seven structural liners were used to span the entire mile of sewer Two additional manholes were installed around the sanitary sewer obstruction at these locations the process sewer was also encased in concrete and had to be cored. New Manhole #2 Sanitary Manhole 48 Concrete Core New Manhole #1 Bypass Piping

25 Weather Challenges Bypass Pump Failures Winter arrived with record low temperatures during lining operations During a night of -30 C temperatures six out of eight bypass pumps failed, for different reasons (dead battery, frozen impellor, clumping fuel, hydraulic leak, oil leak, and broken starter) Fortunately, no lining operations were underway and brewery was returned to gravity flow no interruption to brewery operations Bypass was restored and additional safety measures were applied to address the cold weather Lining operations continued with only 1 day lost

26 MANHOLE REHABILITATION State of corrosive decay was alarming All manholes needed cleaning, patching, and, in some cases, sectional replacement New Installed Ring

27 MANHOLE REHABILITATION Primary vault structure from Anaerobic Pre-Treatment was reduced to a shell from original 9-inch wall thickness

28 MANHOLE REHABILITATION Evanco used a combination of pressure wash, re-pointing with epoxy concrete, and structural design/application of high-build, rigid PU to restore structural integrity New pre-cast tops/frames/covers with epoxy undercoats were fitted on renovated shafts

29 LESSONS LEARNED Importance of accuracy in condition assessment and stability assessment for fully-deteriorated sewers Importance of comprehensive design and planning for all elements (including cold weather, high elevations, collateral assets - canal) Importance of having an experienced team of engineers, operations and management personnel Importance of flexibility and innovation in responding to buried unknowns Importance of back-up plans to ensure no plant shutdowns Risk assessment can make or break a project

30 CONCLUSION AND SUMMARY After numerous challenges, the project was completed without any operational impacts on brewery operations or fresh water canal operations Teamwork, planning and experience were essential elements of success

31 THANK YOU! QUESTIONS?