Public Hearing December 12, 2013

Transcription

1 Public Hearing December 12, 2013

2 Commission s Water Transmission System

3 Finished Water Transmission System South Transmission Main

4 South Transmission Main Route South Main Replacement Route from Provin Mountain Reservoir to Route 5 Rotary- Approximately 6 miles

5 Project Drivers STM is 85 years old Multiple failures w/ costly repairs Documented wall pit and weld seam corrosion Vulnerable to future failures and major water supply disruptions Regional pipeline reliability needs are HIGH

6 2004 Leak- Removed Pipe Section

7 Leak Repair History North Barrel in 1961 in the River on Springfield Side North Barrel in 1963 Same Approximate Spot as 1961 Leak South Barrel on Bank on Springfield Side in 2004 South Barrel at Springfield Terminal Chamber in 2009 North Barrel in the River on Agawam Side July 19, ft of 36-inch pipe exposed by the leak Diver reported severe corrosion over a 4-ft length of pipe

8 Leak Detection Survey at CT River Four new leaks found during September 2010 leak detection survey Two on each of the 36-inch River Crossing Pipes One leak was large and one leak was small relative to one another Failure in CT River

9 54-Inch Pipe Failure 11/26/2012

10 Internal Inspection and Lab Analysis Internal Inspection Results Approx. 1,500 feet of pipe inspected Various levels of weld corrosion documented Weld Laboratory Analysis Results Poor weld quality High porosity Lack of fusion Corroded significantly Should evaluate long term repair and replacement options

11 Evaluate Renewal/Replacement Options Do Not Replace, wait and respond to leaks Renew/Repair Option Pipeline repair, valve and appurtenance replacement, internal lining, and cathodic protection Trenchless Structural Liner Pipe Replacement New Pipe Replacement (open cut)

12 Option 1 - Do Not Replace, Repair Not recommended Pipeline welds and sections of pipe wall are in disrepair and chance of repeated failure is high Consequence of failure is high, would present Commission with an unacceptable level of risk Disruption of service impacts to Agawam, Longmeadow, and East Longmeadow as well as all retail customers Option Not Considered Further

13 Option 2 - Pipeline Repair Positives Mostly trenchless construction - minimal construction excavation impacts compared to full pipe replacement. i.e. less traffic issues, environmental controls needs, abutter impacts etc. Construction methods including welding and cement lining are common and readily available. Less engineering and planning required. Negatives Does not address existing external longitudinal weld corrosion or pipe wall pit depth corrosion. Trenchless construction renewal methods typically more expensive than open-cut replacement. Remaining service life UNKNOWN and most likely significantly less than 100 years vs complete replacement or full structural liner options.

14 Option 3 Trenchless Pipe Replacement Positives 1. Mostly trenchless construction - fewer construction excavation impacts compare to full pipe replacement. 2. Large diameter trenchless construction becoming more common past similar applications. 3. Permitting fewer impacts to existing resource areas. 4. Longer service life when compared to the pipe repair option with 100 yr. life possible. Negatives 1. Trenchless construction renewal methods typically more expensive than open-cut replacement. 2. Higher construction complexity and risk. 3. Diameter reduction would reduce pipeline hydraulic capacity. 4. Fewer specialty construction contractors typically not local to Western Massachusetts. 5. Future pipeline modifications or repairs more difficult compared to new stand-alone pipeline.

15 Option 4 New Pipe Replacement Positives Negatives 1. All new pipe with established materials (e.g., high strength steel) and fabricated to the latest AWWA Standards. 2. Internal and external linings for pipe corrosion protection. 3. Pipe installation methods common, allowing local contractors to bid on project. Availability of state and regional contractors encourages more competition. 4. Longer service life when compared to the pipe repair/renewal option. 100 yr. life design criteria. 5. Can bid multiple pipe replacement material (e.g., PCCP, steel, others) to increase competition among pipe manufacturers. 6. Highest hydraulic capacity of all the options. 1. Permitting temporary impacts to identified resource areas including streams and endangered species areas. 2. Most complex design to allow for alternative pipe material options. 3. Highest disruption to traffic and abutters due to open-cut construction impacts.

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17 Environmental Permit Summary Permit Type US Army Corps of Engineers MassDEP - Waterways MassDEP Water Quality Certification MassDEP Air Quality Local Conservation Commission MassDOT MBTA/Railroad Other State/Federal Permits MEPA Mass. Historical Commission Coastal Zone Management MDEP Drinking Water Permits Strategy Category 1 Permit Submitted Not Applicable Submitted Not Applicable Received Negative Determination Submitted Not Applicable Not Applicable Not Applicable None Not Applicable Not Required

18 Permitting & Environmental Impacts Right-of-Way impacts minimal work within existing ROW, Commission owned property Wetlands minimal wetland impacts work exempt per Agawam Conservation Commission Endangered Species defined NHESP box turtle area within ROW permits to define acceptable work periods MEPA Not required Historic Resources None Stormwater NPDES permit for construction activity Erosion & Sedimentation Controls will be specified and implemented

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20 Replace 54-in and 48-in Welded Steel with Riveted Joints Option 2 Option 3 Option 4 C&L & WELD REPAIR w/ Cathodic Protection Structural Liner PCCP STEEL DI UNIT COST / LF $560 $1,160 $688 $585 $883 Replace 30,900 LF of 54-in & 48-in Welded Steel with 48-in Welded Steel Pipe $17,304,000 $35,844,000 $21,259,200 $18,076,500 $27,284,700 Project Development Contingency (25%) $4,326,000 $8,961,000 $5,314,800 $4,519,125 $6,821,175 Subtotal Total Conceptual Estimate of Construction Costs (August 2012) $21,630,000 $44,805,000 $26,574,000 $22,595,625 $34,105,875 Allowance for Engineering and Implementation (15%) Total Conceptual Estimate of Project Costs (August 2012) $3,244,500 $6,720,750 $3,986,100 $3,389,344 $5,115,881 $24,874,500 $51,525,750 $30,560,100 $25,984,969 $39,221,756 Total Conceptual Estimate of Project Costs (2.0-yrs to Mid-Point of Construction September 2014) (2012 dollars using 4% per year) $26,904,259 $55,730,251 $33,053,804 $28,105,342 $42,422,252

21 Estimated Impact to Customers 54" Transmission Main estimated project cost $32,000,000 Estimated additional annual debt service and 2% $2,000,000 Estimated additional annual debt service for Springfield & Ludlow $1,500,000 Cost of supply, transmission, distribution of water FY2013 $28,216,656 Increase % over FY2013 cost 5.32% Residential water rate FY2014 $2.50 Increase in residential water rate $0.13 Typical annual residential household water bill FY 2013 (120ccf) $ Increase over FY2013 bill $15.95 Cumulative project impact on typical water bill (20 years) $ Estimated additional annual debt service for Wholesale Customers $500, Agawam $244, East Longmeadow $113, Longmeadow $112, Southwick $9,200.00

22 Recommendation New pipe replacement (open cut replacement) Preferred alternative Highest design life Lowest overall net present worth value Most benefits to Commission Evaluate multiple pipe replacement materials (e.g., PCCP, welded steel, others) during design

23 Proposed Schedule Final Design Complete by January 16, 2014 Advertise project January 28, 2014 Open Bids March 5, 2014 Award Construction Project by March 25, 2014 Break Ground by September 2014 Complete Construction by December 2016

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