Title
Lift Station 43 Force Main Rehabilitation - Construction Manager at Risk Services Amendment - WS90501000 (Ordinance S-52980) - District 7
Description
Request to authorize the City Manager, or his designee, to execute an amendment to Agreement 162146 with Achen-Gardner Construction, L.L.C. to provide additional Construction Manager at Risk Services for the Lift Station 43 Force Main Rehabilitation project. Further request to authorize execution of amendments to the agreement as necessary within the Council-approved expenditure authority as provided below, and for the City Controller to disburse all funds related to this item. The additional fee for services included in this amendment will not exceed $1.6 million.
Report
Summary
The purpose of this project is to rehabilitate the two existing force mains associated with Lift Station 43 and add a third force main for redundancy. The project will include replacement of two existing ductile iron pipe force mains with new high-density polyethylene (HDPE) force mains, adding a new third HDPE force main with a new discharge structure on the Southern Avenue Interceptor. Work will include installation of three new air release valves and valve vaults, and rehabilitation of existing valve vault #3 including new piping, valves, and sealing the vault from groundwater infiltration. These improvements will enhance system reliability, increase capacity, and provide redundancy for critical wastewater conveyance infrastructure.
This amendment is necessary because the condition assessment identified deteriorating pipe conditions due to corrosive soils, particularly north of valve vault #3, as well as the need to increase system reliability and redundancy through the addition of a third force main. Additionally, the complexity of construction near existing Salt River Outfall and Southern Avenue Interceptor gravity sewers, including required jack and bore operations and expanded scope for valve vault and air release valve improvements, necessitates additional resources. This amendment will provide additional funds to the agreement to complete the required improvements and ensure the long-term performance and resilience of the force main system.
Contract Term
The term of the agreement remains unchanged. Work scope identified and incorporated into the agreement prior to the end of the term may be agreed to by the parties, and work may extend past the termination of the agreement. No additional changes may be executed after the end of the term.
Financial Impact
The initial agreement for Construction Manager at Risk Preconstruction and Construction Services was approved for an amount not to exceed $7.6 million, including all subcontractor and reimbursable costs. This amendment will increase the agreement by an additional $1.6 million for a new total amount not to exceed $9.2 million, including all subcontractor and reimbursable costs.
Funding for this amendment is available in the Water Services Department's Capital Improvement Program budget. Payments may be made up to agreement limits for all rendered agreement services, which may extend past the agreement termination.
Concurrence/Previous Council Action
The City Council approved Construction Manager at Risk Services Agreement 162146 (Ordinance S-51460) on December 4, 2024.
Location
General Location: S. 75th Avenue and W. Broadway Road
Council District: 7
Department
Responsible Department
This item is submitted by Assistant City Manager Ginger Spencer, Deputy City Manager Amber Williamson, the Water Services Department and the City Engineer.