Award Bid - 2024 Sewer and Manhole Rehabilitation Proj No. 122-019 - Visu-Sewer, LLC

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RECOMMENDED BY-PASS PLAN PROCEDURE NOTE: By-pass Plans are generated after a visual inspection of the job site is complete. When it is necessary, the By-pass Plan will be approved by the responsible City and/or State official before work on the job site is initiated. The assessment of the necessary by-pass plan includes the following steps: • Establish the flowrate within the pipeline section which is to be bypassed. • The best way to do this is by physical measurement with the pipe full to various depths. There are a range of instruments on the market to do this, but it may not always be possible to make measurements with the pipeline filled to a range of depths, and you may have to use other methods. • Many cities keep records of the flowrate within their wastewater systems, and you may be able to obtain accurate values of the flowrate within a given pipeline by contacting the appropriate City department. • Based on these calculations, establish what maximum flow volume the pumps will have to handle at the maximum pipeline capacity. • Determine the type, length and number of bypass lines to be used. • Once you have established the maximum flowrate which is to be handled by the bypass pump(s),you will need to make a preliminary estimate of the bypass pipe arrangement which will be necessary to handle this flow. Use the attached manufacturer’s data tables and/or graphs to determine the pressure loss encountered over the necessary length of line, and add the suction lift and pressure losses due to bends in the bypass lines if applicable. Avoid selection of a line size that operates at or near its maximum flow capacity, as this may correspond to the maximum pressure rating of the line material, and will prevent any increase in volume pumped if it should become necessary.