17-REQ-0002500 Southe West Water Treatment Plant Flocculation Improvement Project - Project Overview 7.17.2025.pdf

Southwest Water Treatment Plant Flocculator Improvements

CIP 113010

Project Overview

GLWA Overview

The Great Lakes Water Authority (GLWA) draws water from Lake Huron and the Great Lakes tributary, as well as the Detroit River GLWA’s five water treatment facilities provide high quality, safe drinking water for regional distribution GLWA operates and maintains 816 miles of water transmission mains GLWA provides water to 112 communities in eight Southeast Michigan counties

Southwest Water Treatment Plant Overview

Plant located at 14700 Moran Road, Allen Park, MI 48101.

Plant went into operation in 1964.

Raw water treated at the plant is drawn from the Detroit River at the Fighting Island intake. The raw flows to the plant by gravity through a 12-foot diameter, four-mile long tunnel.

Plant built with capacity of 240 MGD. Derated as of last Sanitary Survey to 156 MGD. Flows get as a low as 25 MGD and as high as ~100 MGD. 80% of the time flow between 40-80 MGD.

Southwest Water Plant Flow Diagram

Project Overview GLWA is seeking engineering services for flocculation system improvements at SWWTP to include:

Comprehensive Project Management Project Coordination Engineering Design Construction Bid Assistance Construction Administration Resident Project Representation (RPR) Training Record Document Services

The scope of work specifically involves the replacement of existing walking beam flocculator drives, motors, control panels, bearings, instrumentation, and related appurtenances with new vertical flocculators.

Project Objectives Primary Objectives:

• Demolish and replace the flocculators at the SWWTP.

• Maintain treatment capacity at the plant during construction.

Other Project Objectives Include:

• Ovation control and monitoring

• Replacement or coating of miscellaneous steel and piping within each basin

• Demolition of existing ladders or rungs within the flocculator building that are in poor condition or not up to code. Provide new ladders to access each basin.

• Exhaust fans and ventilation improvements

• See Scope of Work for further details

Flocculation Process Overview Original paddle style horizontal flocculators were first put into service in 1964. These were replaced with the existing walking beam flocculators put into service in the early 2000s under Contract

DWS-814.

2 rapid mix systems (1 and 2) that each feed 2 flocculator basins (numbered as 1A/1B and 2A/2B) There are existing openings between raw water inlet conduits that allow flow from either rapid mix train to feed any flocculator.

Each basin receives raw water through 6, 30” influent butterfly valves that discharge into a 4’0” W inlet baffle.

Flocculation Process Continued Each basin has 5-stage, 130’ across, tapered walking beam flocculator system Each basin has 5 channels; each channel is separated from the other with a baffle wall that is solid except for 6, 4’0” W x 3’6” H openings Last flocculator channel discharges into the sedimentation basin; goes through baffle wall that is solid except for 6, 4’0” W x 5’6” H openings Weir wall with a perforated baffle wall at the inlet of the sedimentation basin

Influent Butterfly Valve, Influent Baffle Typical (flow going right)

Influent Baffle Typical

Basin 1A Plan View

Issues with Existing Flocculation Equipment

Poor condition beyond reasonable repair Excessive maintenance to keep in service Flocculator basin 1A has been decommissioned due to decreased demand at the plant

Existing Conditions – Typical Handrails

Flocculator Drive Concrete Pads

Existing Conditions – Walking Beam Flocculators as Viewed at the Floor Level

Flocculator Control Switches and

Emergency Shutdowns

Existing Conditions – Examples of Rung Ladders within the Basins

Walking Beam Flocculator Paddles and Drop Arms

Typical Cages, Gates, and Fencing

Existing Conditions – Example of a Typical Influent Baffle Wall

Wall Openings Between

Flocculator Stages

Typical Bearing Concrete Pads

Existing Conditions – Photos from Electrical Building for Flocculators

Vertical Flocculator Design and Implementation

Install new vertical paddle or impeller flocculators for 3 basins (desired to be 5 stages or less); new equipment must be maintainable and adequate clearances must be provided Determine necessary number of vertical flocculators required based on engineering judgement, supplier recommendations, and hydraulic modeling.

Determine optimal velocity gradients for the flocculators.

Complete a life cycle cost analysis when selecting between alternative equipment or methodologies

Vertical Flocculator Installation:

Structural Considerations

Concrete coring required for each vertical flocculator Assess the existing structure and design any necessary structural improvements to accommodate vertical flocculators

Electrical Upgrades for Flocculation Existing electrical equipment should be assessed for reuse or replacement Provide new motors with overcurrent protection for the new flocculators Provisions shall be included that protect the new equipment from over torque conditions.

Provide 1 VFD cabinet to control for each stage with consideration of 1 or more individual flocs being out of service.

New electrical service and wiring.

Evaluate each existing conduit for reuse.

Additional Scope Verify current handrails adequate;

refinish/replace as necessary Condition assessment of exhaust fans/ventilation improvements Ovation control and monitoring Replacement or coating of miscellaneous steel and piping within each basin Demolition of existing ladders/rungs in poor condition/not up to code; provide new ladders to access each basin Ensure design considers and includes any necessary provisions for maintaining new equipment

GLWA’s Targeted Milestones and Desired Durations for Project

Phases Task Duration / Milestone DateProject Phase / Milestone TBD by procurementStart Work Notice

120 days from start work noticePreliminary Design Phase 270 days from start work noticeFinal Design Phase

270 daysConstruction Bid and Award Phase

850 daysConstruction Phase 90 daysProject Closeout Phase

Evaluation Criteria Each response will be evaluated on its responsiveness to the criteria identified below:

Oral Interviews: The top 3 vendors will be required to make a formal presentation, provide further clarification on their proposal, and GLWA will interview the project team and proposed project manager. The oral interview will be considered in the overall score.

WeightEvaluation Criteria 49%Technical Work Plan 48%Experience and Qualifications 3%B.I.D – Economic Equity

Site Walk

Please do not touch or open anything.

Please stay with the group.

Know Emergency Procedures and Exit Routes PPE required:

Steel/composite toe safety boots Hard hats

Questions/Discussion