In 2019, City staff recommended a North Wastewater Treatment Plant (NWWTP) study to re-evaluate the plant's short-term and long-range operational objectives. In September 2019, a Request for Qualifications (RFQ) was submitted for professional services for the study. Five (5) Engineering firms submitted RFQ's and Carollo Engineers, Inc. was selected following Policy PU-109.
In September 2022, Carollo Engineers, Inc. finalized the Preliminary Engineering Report (PER) for the NWWTP. The PER recommended phasing this project into five (5) groups. Group 1 consists of the highest-priority projects. Phase 1a includes rehabilitation for the stormwater clarifiers.
The fees for phase 1a were negotiated with Carollo staff on a time and material basis. The scope of professional services includes, but is not limited to, the following:
- Prepare a project quick reference plan;
- Provide survey for two stormwater clarifiers;
- Conduct two site visits and prepare a basis of design memorandum;
- Facilitate a preliminary design workshop;
- Provide final design drawings and specifications for the phase 1a improvements identified within the PER;
- Create "Bid Ready" documents;
- Assist with TCEQ Coordination;
- Provide assistance with bidding.
The City identified several additional rehabilitation items to be added during the 30% preliminary design submittal workshop to address some of the urgent needs of the NWWTP. Those additional rehabilitation items included the following:
- Replacement of sludge underflow and drain yard valves for both stormwater clarifiers;
- Incorporation of a new sum pumping system for both stormwater clarifiers;
- And rehabilitation of the existing stair access at stormwater clarifier #2.
These additional design services were not part of the original scope of services. Additional surveying, Subsurface Utility Engineering investigation, and design are required for the additional work, which results in a $83,537.00 increase to the original design contract amount. An additional 21 days have also been added for this project's 100% Design submittal.
The Engineering and Public Works Departments recommend that the City Council authorize the approval of the Design Contract Amendment No.1 with Carollo Engineers, Inc. for the North Wastewater Treatment Plant Improvements - Stormwater Clarifiers Rehabilitation, CIP WW2003, in the amount of $83,537.00.