Oakland Macomb Interceptor Drain Rehabilitation State Revolving Fund Project Plan Overview. Public Meeting June 10, 2009

Transcription

1 State Revolving Fund Project Plan Overview Public Meeting June 10, 2009

2 What is the OMI? The OMI is the Oakland Macomb Interceptor Sewer. The OMI transports much of the sanitary sewage from Oakland and Macomb Counties to the Detroit Water & Sewerage Department (DWSD) for treatment. The OMI is a 21 mile long pipe tunnel. The OMI is between 3 0 and 12 9 in diameter (mostly over 8 ) The OMI is buried up to 100 deep. The OMI serves about 830,000 people.

3 What is the OMI Service Area?

4 Who does the OMI Service? City of Auburn Hills City of Clarkston City of Rochester City of Rochester Hills Independence Township Oakland Township Orion Township Oxford Township West Bloomfield Township Waterford Township Village of Lake Orion Village of Oxford City of Fraser City of Sterling Heights City of Utica Chesterfield Township Clinton Township Harrison Township Lenox Township Macomb Township Shelby Township Washington Township Village of New Haven

5 Where is the OMI located? Begins at Dequindre and Avon Roads An arm follows M-59 Follows Clinton River and Utica Road to Dodge Park Road. Follows Dodge Park Rd. to 15 Mile Road. Follows 15 Mile Rd, to the ITC (Edison) Corridor Follows the ITC Corridor to 9 Mile Road. Follows the Railroad ROW to just south of Eight Mile Road.

6 What is the History of the OMI? Built in the early 1970s by Detroit Water and Sewerage Department Series of Construction Contracts Included the 15 Mile and Romeo Arms in Macomb County Three Collapses on15 Mile 1978, 1980, 2004 Major Disruption Occurred Loss of Service Environmental Impairment Surface Disruption $200,000,000 in Repair Costs (current dollars) INSERT FIG 4

7 What Disruption is Caused by a Collapse?

8 What is the OMI s Current Condition? The OMI was inspected in 2007 and Visual inspection was conducted by staff and by using CCTV. Much of the pipe exhibited moderate to severe deterioration. Voids were detected above the pipe in a number of areas. Infiltration through cracks will continue to deteriorate the pipe. Projecting Reinforcing Steel Crown of Pipe Severely Deteriorated

9 Why is the Project Needed? The OMI was constructed using the same design, materials and contractors in the same soil conditions and at the same time as the 15 Mile Road Interceptor. The 15 Mile Road Interceptor has failed three times with catastrophic results. Rehab will prevent environmental impairment. Rehab of the OMI will prevent collapse at costs far less than future repairs.

10 Where are the Problem Areas? High Distress Areas Avon Arm (M 59) 2 areas 15 Mile west of corridor Corridor south of 15 Mile Corridor at I 696 Corridor at 10 ½Mile Corridor south of 10 Mile Medium Distress Areas Utica south of M 59 Dodge Park south of 18 Mile Dodge Park south of 16 Mile Corridor north of 12 Mile Corridor south of 11 ½Mile Localized Distress Throughout INSERT FIG 8

11 What are the Alternatives? Three Alternatives were analyzed The first is the No Action Alternative The second is the Replacement Alternative The third is the Rehabilitation Alternative

12 What is the No Action Alternative? THE OMI would remain in service with no repair or rehabilitation. Structural defects would remain and expand. Pipe failure collapse could be anticipated at some unknown time. Initial Capital cost would be Zero. Additional user cost would be Zero. Future Repair cost could be Significant. Potential Environmental Impact is Severe.

13 What is the Replacement Alternative? The existing pipe would be replaced in a tunnel roughly paralleling the current route. Construction would disrupt many neighborhoods. Initial Capital Cost would be $499,000,000. Additional User Cost would be about $103 per year per customer over 20 years. INSERT FIG 7

14 What is the Rehabilitation Alternative? Control Structures would be constructed to allow work inside the tunnel while maintaining service to customers. Structural lining would be constructed in severely deteriorated areas. Cracks and leaks would be sealed to prevent further deterioration. Initial Capital Cost would be about $160,000,000. Additional User Cost would be about $35 per year per customer over 20 years.

15 How do the Alternative Costs Compare? ALTERNATIVES No Action Replacement Rehabilitation Estimated Capital Cost $ $ 499,000,000 $ 160,068,220 SRF Interest Rate 2.50% 2.50% 2.50% Term in years Estimated Annual Payment $ $ 32,009,417 $ 10,267,917 Estimated Annual O&M Cost $ 832,529 $ 832,529 $ 832,529 Estimated Total Annual Cost $ 832,529 $ 32,841,946 $ 11,100,446 Service Area Population 832, , ,902 Average Household Size Number of Customers 319, , ,120 Estimated Annual Cost per Customer over 20 years $ 2.61 plus potential repair costs $ $ 34.78

16 What Alternative has been selected? The Rehabilitation Alternative provides for construction leading to a tunnel with a useful life of at least 20 years. The alternative does not require area wide disruption that Replacement would. The alternative will protect against catastrophic collapse that is a potential of No Action. The annual user cost of about $35.00 (over 20 years) will be much less than potential repair costs and is a reasonable addition to current rates.

17 When will the Work Take Place? Design Efforts: Construction Efforts: Year Quarter Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Project Component Hydraulic Study Modify Corridor Gate Supplimental Geotech PCI 5 Gate PCI 5 Rehab PCI 5 Grouting PCI 8 New Gate PCI 9 Temp fix of hole PCI 8 New Access Shaft PCI 8 Rehab PCI 7 Corridor Bypass PCI 7 Rehab PCI 7 Grouting PCI 11A Rehab PIC 6 New Gate PCI 6 Rehab PCI 6 Groutimg PCI 9 Control Structure PCI 9 Rehab PCI 10B Rehab PCI 10A Rehab

18 What are the Social & Environmental Impacts? Without Replacement or repair collapse of the OMI could cause up to 83 million gallons of raw sewage to be discharged by tributary communities per day. During Rehabilitation surface disruption to open space and parkland may take place that will be mitigated upon completion. Minor construction related impacts will also occur. These impacts include additional noise, dust, sediment and traffic. These will be minimized by staging construction and implementing best management practices. No Historical or Archeological sites will be disturbed as part of the Rehabilitation.

19 Any Questions or Comments?

20 Thank You for Your Interest!