This is a service / maintenance or supply contract in Peoria, Illinois. Contact the soliciting agency for additional information.

Scope of Work All in accordance with these Specifications, the scope of Project 2874 (the Project) includes, minimally, the cleaning of Digester 2 and, potentially, the cleaning of Digester 4. Proposals for the completion of work within and at the site of Digester 4 are to be considered as a potential alternate addition to the scope of any contract awarded by the District. The locations of Digesters 2 and 4 are as shown on the Plan Map that has been made part of the appendices of these Specifications and Contract Documents. Solids and liquids removed as part of the cleaning process are to be separated, with removed liquids returned upstream of the headworks of the District's wastewater treatment plant (WWTP) and solids ultimately disposed via landfilling. To assist the Contractor to these ends, information has been provided about the District's WWTP processes, past means and methods utilized towards the cleaning of digesters at GPSD, specifications and project constraints. Site Address: 2322 S. Darst Street, Peoria, IL 61607 City: Peoria County: Peoria State/Province: IL The scope of work to be performed by the Contractor shall generally include, but not be limited to, the following as necessary to complete the work: 1. The determination, provision and administration of all measures necessary to safely perform the work in accordance with all local, state and federal laws, statutes, regulation and requirements; 2. The performance and completion of all administrative tasks necessary to perform the work as specified in these Specifications and Contract Documents; 3. The provision and management of all labor, equipment and materials necessary to perform tasks necessary for the completion of digester cleaning operations; 4. If necessary, the provision, maintenance and removal of any traffic control measures including, but not limited to, signs, barricades, cones, ramps, etc.; 5. All efforts to both coordinate with District staff and adjust plans for the completion of the work in response to comments and directions from District staff; 6. The provision, placement, maintenance, operation and deconstruction of any pumping systems including all components thereof; 7. The placement and securing of any discharge hosing into a receiving manhole upstream of the headworks of the District's WWTP; 8. The provision, placement, maintenance, operation and deconstruction of any measures necessary to protect District assets during the completion of the work; 9. Although not required, any hauling and landfilling of solids removed from digesters to be cleaned; and 10. Any other tasks not specifically listed but required for the complete, thorough and specified cleaning of Digester 2 and, if desired by the District, the specified cleaning of Digester 4. The Contractor with whom the District enters into an agreement for the completion of the work shall be solely responsible for the means and methods utilized to complete the desired ends; however, since the Contractor's work has the potential to impact the wastewater treatment processes at the District's WWTP, any and all aspects of the Contractor's plan for the completion of the work shall be subject to either approval or rejection by the District. The scope of work to be performed by the District shall generally include, but not be limited to, the following as necessary to complete the work: 1. All efforts to both coordinate with designated Contractor staff for the purpose of realizing the safe and efficient completion of the work both in accordance with these Specifications and in compliance with other responsibilities of the District; 2. Prior to the commencement of cleaning operations by the Contractor, and in accordance with the schedule agreed-upon by both the Contractor and the District, all adjustments of processes as needed to isolate a digester, or digesters, to be cleaned; 3. To the extent possible, as determined by District staff, the performance of all measures necessary to remove materials from a digester to be cleaned using existing, in-place, immobile, pumping systems; 4. From a given digester to be cleaned, the removal of the four gas guns from a digester; 5. After completion of the Contractor's digester cleaning efforts, the replacement of the existing gas guns into the recently-cleaned digester; and 6. The completion of measures necessary to reinstate the operational-status of a cleaned-digester back. Information About GPSD WWTP Processes The District's WWTP has a design-average-flow (DAF) of 37 MGD and a design-maximum-flow of 154 MGD. At the heart of the treatment process is secondary biological-nutrient-removal (BNR) process that has a design capacity of 60 MGD. Supporting the BNR process are both four primary clarifiers and a tertiary process designed for further nutrient removal, including two tertiary clarifiers. For the purpose of dewatering both waste solids removed from the secondary process and those removed from the tertiary clarifiers is a set of gravity-belt-thickener (GBT) units. Solids removed from both the primary clarifiers and the GBT units are sent to the four mesophilic anaerobic digesters (digesters) for further processing. Upstream of the District's WWTP, a portion of the sewage collection system collects a combination of both sanitary sewage and stormwater collected through stormwater inlets; therefore, the treatment processes of the WWTP are significantly impacted by wet-weather events. As prescribed by regulatory authorities, the WWTP must operate in different modes depending on flow rates to the WWTP. Through the secondary process, the District must treat up to a maximum of 60 MGD; the variability in flow rates through the processes significantly impacts detention times and therefore processing capacities. Past Efforts Towards Cleaning Digesters at GPSD Past efforts to clean the District's digesters have utilized existing processes and equipment at the District's WWTP to separate and dispose of both solids and liquids from digesters. Since the operations of the digesters is critical to the District's wastewater treatment process, prior digester cleaning efforts have proceeded such that a minimum of three digesters remain both fully operational and regulatory compliant at any given time. Past means and methods are described in part below; however, in no way is an awarded contractor bound to replicate such means and methods when completing the work in accordance with these Specifications and Contract Documents. Prior to the commencement of the cleaning of any given digester, the influent thereto was valved-off and existing, in-place, screw centrifugal pumps were utilized to remove both liquid and solids materials from the digester to the District's drying beds. This phase of removal continued until the existing, in-place, pumps were unable to both physically and safely continue to remove materials; after this phase of the work, the remaining materials was constituted largely of settled solids. Typically, the duration of time spent removing materials using the in-place pumping system was one to two weeks prior to the commencement of alternative solids removal means and methods. Prior to the entrance of personnel into a digester, GPSD staff removed the four gas guns from the interior of the digester to be cleaned. The guns were moved to another location within the District's WWTP campus, where both cleaning and preventative maintenance were performed by District personnel. The openings at the locations of the gas gun mountings were then available for use in cleaning operations. After cessation of removal efforts using the in-place pumping system, the consistency of the settled solids was such that water has to be added to facilitate further solids removal efforts. Water was pumped from the surface of nearby Secondary Clarifiers 6 and 7, near the inner-portion of the effluent weirs, in a manner that minimized disruption to the settling within the utilized clarifiers. The choice between utilization of either Secondary Clarifier 6 or Secondary Clarifier 7 was based on the timing of the digester cleaning efforts and the operational status of Secondary Clarifier 7; during much of the second-half of any given calendar year, the District disables Secondary Clarifier 7 for process optimization purposes. Water was pumped into the digester being cleaned in manner that both provided greater fluidity and allowed the movement of solids using controlled hydraulic pressure. Within the digester, the District removed the slurry within using six-inch hydraulic pumps with discharge hose laid from the pump to the discharge manhole located upstream of the WWTP headworks. The location of the discharge manhole is shown on the Plan Map included within the appendices of these Specifications; the sewer associated with the discharge manhole is an eighty-four-inch (84") interceptor. Entrance into the digester by personnel was required to both manually and hydraulically move settled solids horizontally such that it could be pumped out of the digester being cleaned. This effort continued until all solids were functionally removed from the digester. After the cessation of digester cleaning operations, and all equipment was removed, the gas guns were reinstalled by District staff. Once all components of the cleaned digester were back in place, the digester was again filled and placed back into service. If another digester was scheduled to be cleaned in sequence, disabling of another digester was delayed until the one recently cleaned was again fully operational. Throughout the performance of the entirety of the work, the District abided by all local, state and federal regulations and requirements, including those pertaining to safety. Specifications Digester 2 shall be cleaned such that all materials are functionally removed from each digester; if the alternate proposal is accepted, Digester 4 shall be cleaned to the same expectations. Ninety-nine percent (99%) of all liquid and solids materials remaining after cessation of the District's removal efforts shall be removed by the Contractor and disposed of in accordance with directions provided within these Specifications. Project Constraints The Contractor shall be solely responsible for determining the means and methods for the completion of the work; however, the Contractor shall proceed in accordance with the following conditions: 1. The Contractor shall realize that materials removed from a digester and disposed of uThis effort continued until all solids were functionally removed from the digester. After the cessation of digester cleaning operations, and all equipment was removed, the gas guns were reinstalled by District staff. Once all components of the cleaned digester were back in place, the digester was again filled and placed back into service. If another digester was scheduled to be cleaned in sequence, disabling of another digester was delayed until the one recently cleaned was again fully operational. Throughout the performance of the entirety of the work, the District abided by all local, state and federal regulations and requirements, including those pertaining to safety. Specifications Digester 2 shall be cleaned such that all materials are functionally removed from each digester; if the alternate proposal is accepted, Digester 4 shall be cleaned to the same expectations. Ninety-nine percent (99%) of all liquid and solids materials remaining after cessation of the District's removal efforts shall be removed by the Contractor and disposed of in accordance with directions provided within these Specifications. Project Constraints The Contractor shall be solely responsible for determining the means and methods for the completion of the work; however, the Contractor shall proceed in accordance with the following conditions: 1. The Contractor shall realize that materials removed from a digester and disposed of upstream of the headworks of the District's WWTP can have a significant impact on the District's WWTP processes.pstream of the headworks of the District's WWTP can have a significant impact on the District's WWTP processes. Regulatory requirements imposed on the District will remain uninterrupted by the completion of the work; therefore, the Contractor shall coordinate with designated District staff to assure that increased pollutant loading to the WWTP processes does not create an unmanageable risk for the District. Prior to the start of Contractor activities to remove solids and liquids from a digester, the Contractor shall submit a plan for approval by the District. After submittal of a plan, if the District provides comments or concerns, the Contractor shall revise the plan and resubmit accordingly. Such a plan shall be reviewed for conformity with the following constraints: a. The Contractor shall not commence solids and liquid removal activities from a digester if flows through the District's secondary bioreactors exceed 30 MGD as measured by the appropriate District flow meter. For reference, the range of flows during a typical, dry-weather, day, not preceded by a significant wet-weather event, is from 15 MGD to 20 MGD; therefore, experiencing a flow of 30 MGD through the bioreactors requires a wet-weather event; b. The Contractor shall not commence solids and liquid removal activities from a digester if the weather forecast from the National Weather Service (NWS) includes a significant chance of a significant rainfall event for the Peoria-metro area; and c. The Contractor shall not commence solids and liquid removal activities from a digester if the District's First Flush Basin, as shown on the map made part of the appendices, is full or nearly full as determined by the District. Upon approval of a plan for the completion of the work, if the Contractor is directed by District staff to delay, cease or diminish material removal activities, the Contractor shall do so immediately; however, the District will then negotiate with the Contractor for just and reasonable compensation for damages resulting from said disruption. Good planning of when work will be performed can significantly mitigate risks to the District; 2. The Contractor shall realize that the Contractor's activities will be within a functioning wastewater treatment facility, where other operational and capital improvement activities will be occurring throughout the duration of the Contractor's work. The work of others, including that of both District staff and the crews of other contractors, will have differing significance, if any, to the Contractor. If requested to do so by District staff, the Contractor shall participate in any meetings intended to coordinate activities and manage space. If directed to do so by District staff, the Contractor shall adjust planned activities to accommodate; 3. If the alternate proposal for the cleaning of Digester 4 is accepted by the District and included within the scope of the Contract, in an order to be determined by the Contractor, Digester 2 and Digester 4 shall be disabled in sequence, with the order to the determined by the Contractor; furthermore, the second digester shall not be disabled until the first is both placed back into service and becomes fully operational as determined solely by District staff. At any given time, the District must have, minimally, three fully operational digesters. The duration of time between the cessation of all contractor activities within one digester and the removal from operational service of the second digester will be two weeks; however, at the end of said two-week interim, the Contractor will not be required to immediately request the disabling of the second digester. If the Contractor chooses to demobilize and remobilize labor and equipment during any interim between potential digester cleanings, both the choice to do so and the extent thereof shall be the Contractor's decision, exclusively; 4. Upon request by the Contractor and consent by District staff, the District shall start procedures to remove removable solids and liquids from a given digester. The District will remove as much solids and liquids from the digester as possible using existing, in-place, pumping equipment. Typically, this process requires five to seven working days to complete; therefore, the Contractor shall coordinate prudently with District staff. The decision of when to cease efforts to remove materials using existing, in-place, pumping equipment shall be that of District staff alone, and the Contractor shall accept the District's decision without claim for additional compensation in the forms of either time or money. After the District has ceased the removal of materials from a digester, it shall inform the Contractor that the Contractor can commence with alternative means and methods to removal materials from a digester. Once the District has provided the Contractor with said notice, for the purpose of minimizing the duration of time that a digester is disabled, the Contractor shall begin further solids and liquid removal activities within two business days; 5. Once the Contractor is informed by the District that the Contractor's digester cleaning efforts can commence, the Contractor shall complete the work within two calendar weeks after receipt of notice; 6. If requested by the Contractor, the District will consider proposals for finite closures of roadways within the District's WWTP campus. Any closures and detours permitted must be for an approved period of time and must not inhibit the operations of the District; 7. Do to the location of the District's WWTP, relative to the Illinois River, the District must be vigilant in protecting structures within the WWTP campus from damage from hydrostatic pressures resulting from heightened river levels. The elevations of the bottoms of the digesters dictate that they can only be completely emptied when the river level is at or very near normal pool, understood to be approximately 12' stage, or 440.4' elevation, as measured at the USGS station PIAI2 - Illinois River at Peoria, IL (ILX). As the river rises above normal pool, a corresponding amount of material must be kept within the digester to counterbalance pressures on the bottoms of the structures. The required Contractor's proposed plan for the completion of the work, as referenced in Item 1 above, shall also be reviewed for conformity with the following constraints: a. The Contractor shall not commence solids and liquid removal activities from a digester if the level of the Illinois River, as measured at USGS station ILX, is above normal pool, understood to be approximately 12' stage, or 440.4' elevation; b. The Contractor shall not commence solids and liquid removal activities from a digester if the forecasted river level at USGS station ILX predicts a rise above normal pool for the duration of time inclusive of the duration of time that the digester will be empty; and c. The Contractor shall not commence solids and liquid removal activities from a digester if the weather forecast for the watershed of the Illinois River upstream of Peoria includes the forecast for significant and widespread rainfall. The Contractor shall recognize these constraints and plan accordingly; however, the District understands that the weather and, resultingly, the river level can be unpredictable. If work has commenced towards the emptying of a digester and the river forecast unexpectantly changes, the Contractor shall work with District staff towards the definition and implementation of measures necessary to protect District assets. If the Contractor's plan has been approved by the District, and river conditions requires the District to order a cessation of Contractor activities, the District will then negotiate with the Contractor for just and reasonable compensation for damages resulting from said disruption. 8. The Contractor shall be responsible for the provision of all utilities necessary to complete the work; however, water from the District's secondary clarifiers will be made available for removal from the clarifiers by the Contractor; 9. For the purpose of providing contractors with an estimate of solids deposited within Digester 2, starting during the first week of May, using existing, in-place, pumping equipment, the District removed as much material as possible from Digester 2. On Thursday, May 9th, using remote survey equipment, the District profiled the surface of the remaining mixture of solids and liquids within Digester 2; using information gathered, on May 9th, the calculated quantity of mixture remaining was approximately 889 cubic yards. After confirming the capture and accuracy of gathered data, the digester was subsequently placed back into service. Digester 2 was last cleaned in September, 2021. For the purpose of providing contractors with an estimate of solids deposited within Digester 4, starting during the first week of May, using existing, in-place, pumping equipment, the District removed as much material as possible from Digester 4. On Thursday, May 9th, using remote survey equipment, the District profiled the surface of the remaining mixture of solids and liquids within Digester 4; using information gathered, on May 9th, the calculated quantity of mixture remaining was approximately 900 cubic yards. After confirming the capture and accuracy of gathered data, the digester was subsequently placed back into service. Digester 4 was last cleaned in May, 2022. The District cannot know exactly when an awarded contractor will commence work towards the completion of the scope of work within Digester 2, and potentially Digester 4; therefore, the District cannot estimate what conditions within a given digester might be at the time that the Contractor chooses to commence work. Contractors shall use the information gathered to estimate conditions and provide proposals; if actual conditions encountered differ from those estimated by the Contractor, the Contractor shall not make claim for additional compensation in the forms of either time or money.