RFP: Northwest Water Treatment Plant Sludge Dewatering, Removal, and Disposal

OVERVIEW

Brunswick County is soliciting sealed proposals for dewatering, removal, and disposal of sludge at Brunswick County’s Northwest Water Treatment Plant (“NWTP”). The NWTP is a 24mgd water treatment facility. It was constructed in 1984 and treats water from the Cape Fear River via the Kings Bluff Pump Station in Bladen County. Currently, the average raw water flow for 2024 is 14.11 million gallons a day.

The NWTP utilizes chlorine dioxide, polyaluminumchloride, polymer, and sodium hydroxide as its primary chemicals in the treatment of drinking water. Sodium fluorosilicate, orthophosphate, chlorine, and ammonia are also used to finish the water before being pumped to the distribution system.

River sediment is removed from the treatment process via two routes, one being clarifier sludge blowdowns and the other filter backwashes. Each process has its own unique percent solids and can vary widely. Solids from these processes travel to a two-million gallon settling lagoon. The lagoon is equipped with aluminum handrails, a 20/1 sloped bottom, floor pressure relief valves, a supernatant collector weir, and two 1,200gpm Wemco hydrostal pumps. These two pumps are capable of pumping most of the sludge from the lagoon and transferring it to the 80’ circular sludge thickening unit. In the thickening unit, sludge can be stored and thickened until ready to be removed. One 400gpm Wemco hyrdostal pump is currently available along with another 4” attachment point for another pump (contractor supplied).

The initial term of the contract, if awarded, shall be three (3) years. The initial term may be followed by three (3) successive options to renew for one (1) year each. Each renewal option is to be exercised automatically unless either party gives notice of its intent not to renew at least ninety (90) days prior to the end of the then-current term.

SCOPE OF WORK

Brunswick County has established the following objectives for this project.  Any changes to the specifications or Scope of Work will be made in the form of an addendum to this Request for Proposals and will be supplied to all known prospective contractors and posted on the Brunswick County website. Notwithstanding the foregoing, contractors will be responsible for ensuring that they have all addenda. Brunswick County may negotiate and refine the final Scope of Work with the selected contractor. Brunswick County reserves the right to negotiate additional services with the selected contractor at any time after the initial contract award.

A. Mobilization

Contractor must mobilize, be set up to process, and begin processing sludge within two (2) weeks of notice by County. If contractor fails to meet said deadline through no fault of County, contractor may be held liable to County for obtaining other means of sludge removal.

B. Required Sludge Levels

1. Contractor will be required to maintain a sludge level in the lagoon at a point no greater than three (3) feet below the supernatant collection weir.
2. Contractor is strictly prohibited from discharging solids over the weir from the sludge thickening unit. The sludge level in the thickening unit will be maintained at a point no greater than one (1) foot below the discharge weir.

C. Sludge Dewatering and Removal

1. Contractor is responsible for removing the sludge from the thickening unit.
2. Sludge is to be removed at a rate necessary to remain in compliance with Section B: Required Sludge Levels, as set forth above.
3. Contractor is required to provide all equipment and chemicals necessary to facilitate sludge dewatering and removal.
4. Any chemical used in the settling process and in dewatering must be National Sanitation Foundation (“NSF”) approved for use in drinking water.
5. Contractor will operate its own equipment so as to not interfere with the production of drinking water at the NWTP.
6. Contractor must use some means of dewatering the sludge onsite to limit the number trucks entering and leaving the NWTP to no more than four (4) loads per day.
7. Contractor is required to provide its own trucks for sludge removal from the NWTP (subcontractors may be used with prior County approval).

D. Sludge Disposal

1. Contractor must develop its own contracts for disposal sites for the sludge removed from the NWTP and have a contingency plan if land is not available. These sites must be permitted by the NC DEQ for land application of water treatment plant residuals.

1. Contractor is required to provide an annual report to County by January 15 of the following year detailing the location and quantities of sludge that was disposed.

E. Sludge Weighing

1. Contractor must weigh each empty trailer and load of dewatered sludge on certified scales.

1. Contractor must provide copies of weight tickets with each monthly invoice and/or at such other intervals as reasonably requested by County. Invoices will not be paid until weight tickets are provided and matched with trailer numbers and percent solids data.

F. Sludge Sampling

1. Contractor must collect equal size sludge samples at least every three (3) hours when operating its dewatering device. All samples must be an accurate representation of the sludge being produced. Sample(s) will then be composited for each truckload for a percent solids test performed by NWTP staff using standard methods. Composite containers will be made of plastic and have sealing lids to retain and retard the migration of moisture.
2. If contractor pumps and hauls liquid loads of sludge, contractor must collect a 250ml grab sample from each truck which will be composited daily for a percent solids test performed by NWTP staff using standard methods. Composite containers will be made of plastic and have sealing lids to retain and retard the migration of moisture.

G. Contingency Plan

Contractor shall maintain a written plan of contingency capabilities. In the event of natural disasters, emergency operations, equipment failure or other failure beyond contractor’s reasonable control, contractor must provide a list of alternative removal capabilities in the event land application sites are unusable/unavailable.

H. Permits and Regulations

Contractor is solely responsible for ensuring that land application methods and land application rates are in conformance with applicable NC DEQ Permits and Regulations.

I. County Provisions

1. County will provide a two- (2) inch water line that can be used for wash water, if needed. Minimum pressure will be 50psi.
2. County will provide a 100amp, 460v, three- (3) phase power supply, if needed.
3. County will operate the settling lagoon and 1,200gpm Wemco pumps to facilitate sludge removal from the lagoon in as an efficient manner as possible.
4. County will operate the sludge thickening unit to keep it full minus one (1) foot to keep within weir limit. If Contractor requires chemical addition for this stage of the operation, Contractor shall be solely responsible for the operation of the thickening unit and any fines issued by the NC DEQ for NPDES exceedances related to improper operation of the thickening unit.
5. County will provide contractor with 24-hour access to the sludge operating facilities.

J. Calculations for Determining Try Tons

1. Using percent solids data from the composite samples and combining the weights from the weight tickets, dry tons will be calculated on a per truck basis. %solids X wet pounds hauled / 2000 = dry tons removed. This will be verified by weight tickets provided by Contractor.

1. When calculating from liquid loads, percent solids from the daily composite sample will be combined with the total # of gallons removed from the NWTP for that day to calculate dry tons removed. %solids X gallons hauled X 8.34 / 2000 = dry tons removed.

CONTRACTOR REQUIREMENTS

Contractor must be licensed for the specific type of services in the State of North Carolina. Contractor shall have a minimum three- (3) year obligation for the Project, including performing dewatering services which include the pumping, dewatering, loading, transporting, and disposing of non-hazardous residuals in accordance with the Scope of Work as set forth herein for the Brunswick County Northwest Water Treatment Plant located at 3954 Clearwell Drive NE, Leland, North Carolina 28451.

SITE VISIT

A site visit is highly recommended prior to submitting a proposal for the work.  In order to schedule a site visit, contact Thad Hill at 910.253.1771.

PROPOSAL DEADLINE AND SUBMITTAL REQUIREMENTS

Sealed proposals must be received no later than January 28, 2025, at 4:30 pm ET.   Sealed proposals must be clearly marked “Northwest Water Treatment Plant Sludge Dewatering, Removal and Disposal.”   Brunswick County will not be responsible for the failure of any mail or delivery service to deliver a proposal prior to the stated date and time.  Regardless of the manner of submission, any proposal received after the stated date and time or proposals not submitted to the correct location or in the designated manner will not be considered. Incomplete proposals or proposals inconsistent with the required format may be disqualified from consideration.

All proposals must include the following:

• The proposal title and due date and time.
• A cover letter/letter of intent on contractor’s letterhead, signed by an authorized representative of contractor, expressly agreeing to Brunswick County’s terms and conditions contained in this Request for Proposals and its attachments.
• The contractor’s name or company name, address and telephone number.
• The name, address and telephone number of company representatives with the authority to answer questions or provide clarification regarding the proposal’s contents.
• The names of any and all subcontractors expected to perform services in connection with the project and their qualifications.  Include the estimated percentage of work that each subcontractor is expected to perform.   Brunswick County reserves the right to accept or reject any proposed subcontractor.
• A detailed Form of Proposal in substantially the form attached hereto and incorporated herein by reference.
• A full description of services and processes that will be implemented and ongoing to complete the project in the most efficient, timely and comprehensive manner.
• Any assistance requirements from Brunswick County.
• A detailed company description and history, including the areas of expertise related to the project.
• A reference list of at least three (3) current projects or projects completed within the past twenty-four (24) months for projects of similar size and scope, including the name and telephone number of a contact person for each reference listed.
• Certificate of Insurance as evidence that contractor meets the County’s Minimum Insurance Requirements attached hereto.

Contractors shall provide documentation sufficient to clearly demonstrate that their firm meets or exceeds the requirements set forth in this Request for Proposals. Failure to provide such documentation may result in the proposal being deemed non-responsive.

Those interested should submit one (1) sealed hard copy of the proposal. Proposals may only be mailed or hand delivered to the following:

Hand Delivery:
Glenn Walker
250 Grey Water Road
Supply, NC 28462

Contractors are expressly prohibited from contacting any Brunswick County official regarding this Request for Proposals, except in the manner noted in this section. A violation of this provision is grounds for the immediate disqualification of the contractor.