SCWRF Treatment Technology & Flow Management Improvements

Posted At:Fri, Feb 6, 2026 8:29 AM
Sealed Bid Process:Yes (Bids Sealed / Pricing Sealed)
Private Bid:No

As requested by the Engineering and Project Management Division (hereinafter, the “Division or Department”), the Collier County Board of County Commissioners Procurement Services Division (hereinafter, “County”) has issued this Request for Professional Services (hereinafter, “RPS”) with the intent of obtaining proposals from interested and qualified Proposers in accordance with the terms, conditions and specifications stated herein, in the Solicitation and/or attachments. The Proposers at a minimum, must achieve the requirements of the Specifications, Scope of Services or Scope of Work stated. All references to “Proposer” are also referred to as “Consultant,” “Firm,” “Offeror,” “Contractor,” and “Vendor.”

The selected firm shall perform comprehensive design and construction administration services to construct improvements of the Collier County Water–Sewer District’s (CCWSD’s) South County Water Reclamation Facility (SCWRF). Improvements contemplated include, but not limited to the following: Comprehensive plant capacity expansion of peak flow and average flow capacity, flow equalization and pumping; preliminary treatment, coarse screening, grit removal, fine screening; secondary treatment, incorporation of membrane bioreactor (MBR) technology into the plant design, activated sludge processes, filtration, disinfection, effluent and reject water storage and pumping, deep injection well pumping, sludge storage, pumping, and dewatering

The selected firm will perform preliminary design, geotechnical surveys, surveying, subsurface utility engineering, hydraulic modeling, wastewater treatment process modeling, final design, permitting, bidding packages, opinion of probable costs, public involvement services, construction administration services, and construction warranty services. The selected firm will also coordinate with Public Utilities Department staff, Engineering and Project Management Division (“PUD”) staff, neighboring community, local electrical utilities, and the Growth Management and Community Development Department to deliver the planned infrastructure improvements

Specific sections of this scope may be deleted during contract negotiations.

The CCWSD owns and operates the South County Water Reclamation Facility (SCWRF). The SCWRF original construction was completed in 1991. It was expanded to its current maximum month average daily flow (MMADF) permitted capacity of 16 million gallon per day (MGD) in 2005.

The 2025 Annual Update and Inventory Report identified a planned treatment technology and flow management improvement project at SCWRF is expected to increase the plant's treatment capacity by 5.1 MMADF MGD resulting in a total treatment capacity of 21.1 MMADF MGD and is anticipated to be online in FY 2031.

The goal of this project is to implement the necessary upgrades to manage current and projected wet weather demands effectively. This initiative ensures continuous regulatory compliance and expands the capacity to provide treated, reclaimed water for beneficial reuse to customers.

The SCWRF is a modified activated sludge domestic wastewater treatment plant consisting of two (2) 1.25-million-gallon (MG) flow equalization tanks (total capacity 2.5 MG), and odor control system, influent screening, grit removal system, fourteen (14) biological treatment basins consisting of anoxic and aerobic (total capacity 7.0 MG), six (6) turbo blowers and two (2) multi-stage centrifugal blowers to provide process air to the aerations basins, clarifier splitter structure, four (4) circular center feed clarifiers, eight (8) sand filters each 960 sq. ft. (total area 3,840 sq. ft.), sodium hypochlorite chemical feed system, four (4) chlorine contact tanks (total volume 412,000 gallons), two (2) 330,000-gallon aerated sludge holding tanks (total capacity 660,000 gallons), and four (4) belt filter presses for residuals handling. The treatment facility can be operated in modified Ludzack-Ettinger mode or in conventional activated sludge mode.

The SCWRF’s permitted capacity of 16 MGD MMADF could handle influent flows as high as 40 MGD peak hour (wet weather) through the preliminary treatment facility prior to flow equalization. The wet weather peak flows are managed using two (2) preliminary treatment train facilities, two (2) equalization tanks and the use of four (4) existing aeration basins as additional flow equalization.

Effluent disposal consists of the County’s slow rate of public access reclaimed water system and two (2) Class 1 injection wells.

Treatment Technology and Flow Management Improvements

The County has explored the use of Membrane Bioreactor (MBR) to increase peak and average capacity. The selected firm will incorporate MBR technology improvements, or other treatment technology as otherwise approved by the Department, into this project.

The primary goal of the project is to improve wet weather plant capacity to treat a minimum peak flow prior to flow equalization of 56.0 MGD with a minimum average capacity of 21.1 MGD MMADF, or as otherwise approved by the County. The goal of the project is to complete construction by 2031. The design shall include preliminary plans for future improvements including increases in capacity, conversion to advanced wastewater treatment for nutrient removal, and additional or full MBR capacity conversion. The firm selected to complete design within one year (365 days) of issuance of the Notice to Proceed, or as otherwise approved by the Department.

As outlined in a Technical Memorandum dated February 2011, the conceptual concept for capacity expansion at the SCWRF is the potential conversion of a portion of the aeration basin passes to MBR (membrane bioreactor) mode of operation. The proposed work for this conceptual conversion would be the installation of new equipment in some of the existing aeration basins, thus not requiring construction of new aeration basins. The remaining components of the facility expansion would be those which have the potential to be constructed inside a building and other structures located to the north of the aeration basins. A copy of this memorandum is included as attachment 26-8635 Exhibit -Tech Memo #9 Capacity Expansion Considerations February 2011to this solicitation.

The design shall be comprehensive and be integrated and consistent with the entire treatment facility. The firm will be expected to coordinate with the Department (PUD) to define and determine the size, capacity, redundancy, and reliability criteria for the new, existing or improved facilities.

Preliminary Treatment Facility Improvements

The design shall include reliable new preliminary treatment facilities with the capability to take one (1) new treatment train out of service while maintaining wet weather criterion. The preliminary treatment facilities for the MBR treatment trains shall incorporate coarse screening (6 mm), grit removal, and fine screening (2 mm) or as otherwise approved by the Department. The constructed capacity of the new preliminary treatment facilities shall be large enough to treat the entire plant flow, or to reliably take the existing preliminary treatment trains out of service for rehabilitation. The preliminary design shall include the future expansion of the preliminary treatment facility to handle all plant flow and future consideration of increased peak flow capacity.

Flow Equalization Facility Improvements

Review and provide recommendations on flow equalization facilities required for the proposed facilities. At a minimum, subject to review and approval by the County:

• Addition of at least one additional flow equalization tank shall be included.

• Modifications to the existing flow equalization tanks to provide pump stations for each tank dedicated to mixing systems and return of equalized flow to the treatment process.

• Review and modification of the existing flow control facilities that send flow to flow equalization.

Receiving Facility for Vactor Trucks and Pumper Trucks

A facility to receive material from County-owned vactor trucks has been designed by others. The project shall include assumption of this engineering design with a revised location on site at the SCWRF in coordination with the proposed facilities. The design shall be reviewed and modified as necessary to be incorporated in the plant site.

Additionally, at times, the plant receives wastewater from pumper trucks hauling sewage from the CCWSD’s sewerage system. The design shall include facilities to allow for receiving and preliminary treatment of this wastewater along with pumping to the plant’s preliminary treatment facility.

Reclaimed Water Pump Station Improvements :

Evaluate and design improvements to the existing combined reclaimed water and deep injection well pump station to expand its pumping capabilities.

Deep Injection Well Pump Station

Design shall include an independent deep injection well (DIW) pump station to provide effluent disposal at the full rated capacity of the existing DIW systems two (2) wells, at approximately 18 MGD each, and reliable backup for reuse pumping to the existing slow rate public access reclaimed water system. Design shall evaluate the need to mitigate hydraulic pressures.

Existing Activated Sludge Secondary Treatment Improvements

• Evaluate and design improvements to the existing aeration basin tank drainage system including the associated valves and pumping systems.

• Design a comprehensive rehabilitation of the activated sludge treatment mixed liquor splitter structure including flow splitting gates, weirs, aeration system, and structural considerations.

• Evaluate and as necessary, design improvements to the existing clarifiers, associated return pumping systems, and sludge wasting systems. Provide recommendations for improvements to be included in the design.

Tertiary Filtration and Effluent Disinfection

The plant utilizes shallow bed traveling bridge sand filters for tertiary filtration and sodium hypochlorite with chlorine contact basins for effluent disinfection.

• Evaluate and design improvements and replacement equipment for the existing tertiary filtration systems.

• Provide design of tertiary filtration and effluent disinfection to accommodate increased plant average and peak flows as required.

• In the preliminary design, evaluate Ultraviolet Light (UV) Disinfection as an alternative means of effluent disinfection.

Electrical Service and Power Systems

Design shall provide an additional electrical service for the plant including reliable double-ended switchgear, motor control centers, and generators sized for final build out of all passes converted to MBR, as well as meeting all project needs.

Odor Control

Design to include Odor Control System(s) to treat odors for new or modified facilities, and project improvements. The requirement is to remain in compliance with FDEP requirements and County goals to prevent discharge of odors offsite.

Reject and Reclaimed Water Storage

The existing plant uses a repurposed oxidation ditch structure for reject water and reclaimed water storage. The outer ring, 3 million gallons (MG), is generally used for reject water storage, which can either be disposed of by pumping into the deep injection wells or drained to the reject pond for retreatment. The inner passes (3 MG) are used for reclaimed water storage. The effluent pump station draws from the tanks and discharges to either the CCWSD’s slow rate public access reuse system, or to the deep injection wells. The plant has a 4 MG reject water storage pond. Reject water from the pond is returned to the plant though a plant drain pump station.

This project includes modifications of existing tanks and ponds to provide minimum of 3 MG of additional reclaimed water storage (minimum of 6 MG of reclaimed water storage is required) and a minimum of 3 MG of reject water storage in a tank(s) to allow for pumping to the DIW system or retreatment though the plant. The existing reject pond can be modified, retained or eliminated as required for the comprehensive facility design.

Solids Handling Improvements

• Design to include additional aerated sludge holding tank(s) and associated pumping systems to supplement the existing systems as required to provide the required capacity for the facility.

• Design shall include and allocate space for the ultimate future capacity expansion.

• Additional sludge dewatering system(s) potential using belt filter press or screw press technology to provide additional sludge dewatering capacity.

Material Storage Building

Design a material storage building on the SCWRF site. Conceptual size is minimum 40’ x 60’, or as otherwise approved by the Department.

Comprehensive Services and Components

The improvements include, but are not limited to the following components:

• Tanks

• Pumping facilities

• Buildings

• Pumps, piping, valves, and other appurtenances

• Mechanical Systems including plumbing and Heating, Ventilation and Air Conditioning (HVAC)

• Odor Control facilities

• Structural

• Electrical and Supervisory Control and Data Acquisition (SCADA)

• Generator/fuel systems

• Chemical feed systems

• Storm Water improvement and treatment concepts, quantity attenuation, storage, and runoff rate management and reduction

• Access Roads

• Pathway/sidewalk

• Landscaping

• Security

• Site improvements

• Coordination with other construction projects, designed by other professionals