Title
Contract No. 1902658
CSO Outfall Rehabilitation - Phase IV
CIP# 260500/ BCE Score: N/A
Body
Agenda of: December 19, 2019
Item No.: 2019-423
Amount: $5,399,075.00
TO: The Honorable
Board of Directors
Great Lakes Water Authority
FROM: Sue F. McCormick
Chief Executive Officer
Great Lakes Water Authority
DATE: December 3, 2019
RE: Contract No. 1902658
CSO Outfall Rehabilitation - Phase IV
Vendor: Marra Services, Inc.
MOTION
Upon recommendation of Cheryl Porter, Chief Operating Officer - Water and Field Services, the Board of Directors (Board) of the Great Lakes Water Authority (GLWA), authorizes the Chief Executive Officer (CEO) to enter into Contract No. 1902658 “CSO Outfall Rehabilitation - Phase IV” with Marra Services, Inc., at a cost not to exceed $5,399,075.00 for a duration of 18 months; and authorizes the CEO to take such other action as may be necessary to accomplish the intent of this vote.
BACKGROUND
CCTV Pipeline Assessment and Certification (PACP) inspections for portions of the Conveyance System outfalls were completed in January 2015. In combination with combined sewer overflow (CSO) frequency data, these outfalls raised concerns regarding their long-term structural integrity. Manual entry inspections, remote-operated vehicle (ROV) inspections, and additional CCTV inspections were completed in November 2018 through April 2019. Based on the above inspections, a repair plan was formulated. This includes rehabilitation of specifically identified outfalls, including cleaning, structural repairs, regulator gate and backwater gate rehabilitation, and access hatch replacement.
The twelve outfalls generally function in a similar fashion, with dry weather flow diverted to the DRI, and wet weather flow allowed to outfall to the Detroit River. Outfalls B-14, B-16, B-18, B-27, B-28, and B-29 have diversion dams which redirect dry weather flow to their respective regulator chamber, where the flow is then routed to the DRI. In a wet weather event of sufficient size, the dams are overtopped. Outfalls B-9, B-10, B-19, B-21, and B-22 have backwater gates which redirect dry weather flow to their respective regulator chambers and then to the DRI. In a wet weather event of sufficient size, wet weather flow builds up against the backwater gates until a sufficient differential between river level and sewer level allows the gate to open, and a CSO occurs.
JUSTIFICATION
Recent inspections of the Collection System outfalls raised concerns. Inspections revealed structural deficiencies like fractures, missing mortar from bricks etc. and sediment deposits in several of the inspected areas. These inspection reports were further evaluated, and rehabilitation designs and construction documents were developed for CSO Outfalls B-9, B-10, B-12, B-14, B-16, B-18, B-19, B-21, B-22, B-27, B-28, and B-29 under CS-168. The planned rehabilitation of the above-identified outfalls includes cleaning, structural repairs, regulator gate rehabilitation, and access hatch replacement. Rehabilitation of the CSO outfalls is essential to properly discharge the uncontrollable combined sewer overflows to the receiving waters and to prevent sewer back up into the Conveyance System.
FINANCIAL PLAN IMPACT
Summary: Sufficient funds are provided in the financial plan for this project.
Funding Source: Wastewater Construction Bond
Cost Center: Field Engineering
Expense Type: Construction (5421-892411.000-616900-260505)
Estimated Cost by Year and Related Estimating Variance: See table below.
Fiscal Year
FY 2020 Budget $ 1,799,075.00
FY 2021 Budget 3,600,000.00
Financial Plan Estimate $ 5,399,075.00
Proposed Contract Award 5,399,075.00
Estimating Variance $0.00
This proposed contract is being funded from unallocated Program 260500 balances identified in FY 2020 - 2024 CIP Plan.
SAVINGS, COST OPTIMIZATION, AND REVENUE ENHANCEMENT IMPACT
The cost savings are not determinable at the time of award.
COMMITTEE REVIEW
This item was presented to the Operations and Resources Committee at its meeting on December 11, 2019. The Operations and Resources Committee unanimously recommended that the GLWA Board adopt the resolution as presented.
SHARED SERVICES IMPACT
This item does not impact the shared services agreement between GLWA and DWSD.