33 01 30 Operation and Maintenance of Sewer Utilities.pdf

33 01 30 Operation and

Maintenance of Sewer Utilities

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1.0 General

1.1 Section Includes

A. By-pass pumping of sanitary sewers.

B. Pumping and Hauling of sanitary sewers, if needed.

1.2 Scope

A. The work covered by this section consists of the Contractor furnishing all labor, equipment, tools, appliances, and materials necessary to perform all operations to implement a temporary pumping system, or a temporary pumping and hauling system, for the purpose of diverting existing sewage flow around various sections of sanitary sewer piping that are to be replaced and/or rehabilitated for the duration of the replacement and at other periods as determined by the Contractor to prevent sewage overflows and provide reliable sewer service to the users of the sanitary sewer system at all times. The Contractor shall maintain sewage flow in the construction area in order to prevent backup and/or overflow into upstream pipe segments and laterals, adjacent ditches, storm sewers, and waterways.

B. The design, installation and operation of the temporary pumping system and pumping and hauling system shall be the Contractor's sole responsibility.

C. The Contractor is advised that the Owner’s system includes areas which are classified as a “combined” system – meaning that the sanitary sewers and storm sewers are combined into a single subsurface collection and conveyance system. This means that such portions of the system are highly impacted by storm events, such as rainfall or snow melt, and require additional considerations by the Contractor to prevent backups and overflows. The Contractor is encouraged to contact the Owner and Engineer to confirm if the Project Area includes a combined system; however, whether or not the system within the Project Area is combined or separate does not in any way alleviate the Contractor of their requirements, nor is the Owner or Engineer required to or liable for any design flow information.

D. This Section pertains to bypass pumping and pumping and hauling of sanitary sewers, exclusive of short-term or low-flow situations where a commercial, low-voltage trash pump is sufficient to accommodate normal and peak flows.

1.3 Design Requirements

A. The Contractor shall ensure that the bypass pumping system has sufficient capacity to pump the flow around the sanitary sewer section being replaced and/or rehabilitated as part of the proposed sewer improvement work.

B. The Contractor shall ensure that pumping and hauling system is of sufficient capacity and number of trucks to pump and haul flow around the sanitary sewer section being replaced and/or rehabilitated as part of the proposed sewer improvement work.

C. Flow metering was not completed by the Owner and therefore actual flows are not known; however, CCTV inspections were conducted during dry weather periods. It should be noted that the system is a combined sewer system and is highly susceptible

33 01 30 - 2 to groundwater infiltration and inflow during periods of wet weather and the flows can significantly increase from those observed in the CCTV inspections. The Contractor has the option of installing temporary flow metering equipment to verify flow.

D. The Contractor shall provide all pipeline plugs, pumps of adequate size to handle the flow, vacuum trucks and trailers, temporary discharge piping, and fittings to ensure that the total flow of the sewer can be safely diverted around the work. Pumps shall be selected per the results of the flow calculations and per site requirements.

E. The Contractor shall have adequate standby equipment available and ready for immediate operation and use in the event of emergency or breakdown. One (1) standby pump for each size pump utilized shall be installed at the mainline flow bypassing location, ready for use in the event the primary pump fails.

F. The Contractor shall ensure that bypass pumping systems are manned at all times, or provided with an alarm system with autodialer, while operating. The pumping and hauling system shall be manned at all times.

G. The Contractor shall ensure that bypass pumping system is capable of bypassing the flow around the work area and of returning any amount of flow up to full available flow into the sanitary sewer system as necessary for satisfactory performance of the work.

H. The Contractor shall be responsible to ensure that the bypass pumping system and pumping and hauling system adheres to all local, state, and federal codes and regulations as required by the regulatory agencies having jurisdiction.

I. The Contractor shall maintain wastewater flows around the work area in a manner that will protect and not cause surcharging of sewers, drains, damage or flooding to public and private property.

J. The Contractor shall protect water resources, wetlands, and other natural resources during the work.

K. The Contractor shall ensure that the bypass pumping system and pumping and hauling system have provisions for avoiding damage to public and private property; preventing leakage from hoses; and minimizing noise from pumps.

1. All bypass pumps, regardless of size, shall conform to the sound limitation requirements outlined in NASSCO’s written specification for Bypass Pumping

Systems: 70 dba at 23-feet from the source. The measured sound intensity in A-weighted decibels (dba) shall not exceed this limit in all directions radiating from the source.

2. The Contractor shall be responsible to ensure that the measured sound intensity does not exceed the limit provided above. Where there may be a question as to whether or not the sound intensity meets or exceeds this limitation, the Contractor shall be prepared to – and shall – test the measured sound intensity in the presence of the Owner and/or Engineer. The device which the Contractor shall use to measure the noise level shall be calibrated and shall meet the standards of ANSI

S1.25 Personal Noise Dosimeters, and IEC 61252 Personal Sound Exposure Meters.

The device shall have RMS and peak range capabilities corresponding to those expected to be emitted by the source.

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L. It shall be the responsibility of the Contractor to provide protection for the entire bypass pumping system including but not limited to piping, piping connections, pumps and ancillary equipment. Materials utilized for bypass pumping shall be appropriate for the intended operation and service. The Contractor shall be responsible for any damage caused by the Contractor’s failure to provide adequate protection to the bypass pumping system.

1.4 Responsibility of Overflows and Spills

A. It shall be the responsibility of the Contractor to schedule and perform the work in a manner that does not cause or contribute to incidence of overflows, releases or spills of sewage from the sanitary sewer system or the bypass operation.

B. Owner is permittee of the sewer system and subject to fines resulting from sanitary sewer overflows (SSO) and dry weather overflows (DWO). If any action by the

Contractor causes an overflow and/or release or spill of sewage emanating from the bypass operation, and results in a financial penalty levied against the Owner, the

Contractor shall promptly reimburse Owner in the full amount. In these instances, the

Contractor shall fully cooperate with Owner to provide details of the incident and may be subject to subsequent regulatory-issued corrective action plan.

2.0 PRODUCTS

2.1 Materials

A. The Contractor shall provide and maintain adequate pumping equipment, force mains, vacuum trucks and trailers, and other necessary appurtenances in order to maintain reliable sanitary sewer service in all sanitary sewer lines as required for construction.

The Contractor shall have backup pump(s), force main(s), vacuum trucks and trailers, and appurtenances ready to deploy immediately. Appurtenances and discharge point shall be approved by the Owner. Backups and/or overflows and costs associated with such events, as the result of inadequate equipment are the responsibility of the

Contractor.

3.0 EXECUTION

3.1 Preparation

A. The Contractor shall provide bypass pumping or pumping and hauling of sewage and wet weather flows around each segment(s) of pipe that is affected by the Work. The

Contractor shall be responsible for all required bulkheads, pumping equipment, piping, vacuum trucks, trailers, etc., to accomplish the sequence of pumping. The Contractor shall cease bypass pumping operations and return flows to the pump station and/or pipe segment when directed by the Owner. During bypass pumping or pumping and hauling, no sewage shall be leaked, dumped, or spilled in or unto, areas outside of the existing sanitary sewer system. When bypass pumping or pumping and hauling operations are complete, pumps, piping, trucks, and trailers, shall be drained into the sanitary sewer prior to disassembly.

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3.2 Installation

A. The Contractor shall plug off and pump down the sewer manhole or pipe segment in the immediate work area and shall maintain the sanitary sewer system so that surcharging does not occur. Contractor shall man the bypass pumping system and pumping and hauling system when in operation.

B. The Contractor shall ensure that no damage will be caused to private property, city, or state right-of-way as a result of bypass pumping operations and pumping and hauling operations. Ingress and egress to adjacent properties shall be maintained. Ramps, steel plates or other methods shall be deployed by the Contractor to facilitate traffic over surface piping.

C. The Contractor shall complete the work as quickly as possible and satisfactorily pass tests, inspections and repair deficiencies prior to discontinuing bypass pumping operations or pumping and hauling operations and returning flow to the sanitary sewer system.

D. The Contractor shall immediately notify the Owner should a surcharge occur that results in an overflow of sewage. If the Contractor is unable to remedy the situation, then he should suspend or terminate the work until such time as the overflows have been controlled. Should such surcharge damage the materials and/or equipment that is used on the job and/or adjacent property, it shall be corrected at no additional cost to the Owner. In the event that sewage accidentally drains into the drainage system or street, the Contractor shall immediately stop the overflow, notify the Owner and take the necessary action to clean up and disinfect the spillage to the satisfaction of the Engineer. If sewage is spilled onto public or private property, the Contractor shall wash down, clean up and disinfect the spillage to the satisfaction of the Engineer.

E. The Contractor shall locate bypass pumping suction and discharge lines, and pumping and hauling vehicles so as to not cause undue interference with the use of streets, private driveways and alleys. In cases where the suction and or discharge lines are required to be buried for vehicle / pedestrian traffic, cost for this work is incidental and includes complete restoration of any surface features disturbed.

F. The Contractor shall provide concrete or plastic barriers, road ramps, and traffic control for work within state and city right-of-ways as required to protect bypass pumping equipment and piping.

G. The Contractor shall not intentionally damage or remove portions of existing sanitary sewer structures for the purpose of installing bypass pumping system without specific approval from the Owner or Engineer. If a structure is damaged, it shall be reconstructed or replaced to the satisfaction of the Owner at no additional cost to the

Owner.

H. The Contractor shall coordinate the pumping and hauling disposal/dump location with the Owner.

I. The Owner shall not be responsible for damage to the bypass pumping system sustained by the Contractor directly or indirectly as a result of stormwater runoff within streets, ditches. The Contractor shall be responsible for damage that results directly or indirectly from the interference of stormwater runoff to bypass pumping equipment, 33 01 30 - 5 piping and/or appurtenances. It is the intent of these specifications to require the

Contractor to establish adequate bypass pumping and pumping and hauling systems as required regardless of the flow conditions.

3.1 Cleanup and Removal

A. The Contractor shall restore the bypass pump area and the bypass piping route to pre-bypass condition including any cleanup measures necessary due to fuel, coolant, oil, and sewage leaks. The Contractor shall document any cleanup measures that were necessary. The Contractor’s bypass pumping plan shall ensure that all sewage in the bypass pumps, pipes, and fittings has been emptied into the sanitary sewer system.

END OF SECTION