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HomeMy WebLinkAboutSewage Pumping PlantsJuly Ut 1957 V-LA, REPORT ON SEWAGE PWING PLANTS Of THE CITY OF NEWPORT IWACHt CALIFORNIA including RECOMMATIONS FOR DIPROVEMENTS and ESTIMATED CONSTRUCTION COSTS I By: Joseph Kellogg Rice Civil Engineer :, 9AUT°ORIZATIO11 AND PURPOSE • The City Council on June 10, 1957 authorized the employment of the writer to make a survey and report on the City's sewage pumping plants, with recommenda- tions.for improvements and estimated costs thereof. The principal purposes of the survey were: A. To de.- ermiae.means of eliminating undue detention of sewage in wet wells as a part of the City's efforts to prevent build up of sulfides in its sewer lines and coincidentally reduce odor nuisance. B. To make a preliminary estimate of costs involved. However, progress of the survey indicated desirability of increasing the scope of the proposed work to provide better access to the plants, safety measures, and improved working conditions for maintenance forces. RECOMMENDATIONS AND ESTIMATED. COSTS The following tabulation gives a brief description of the major improve- ments recommended to each plant together with a preliminary estimate of costs involved on a contract basis. Plant No. Name Proposed Improvements Estimated Cost 6 Bay Island* Minor Modifications by City Forces $ None 7 Lido Isle Variable speed, matched flow pump- $ 30,451 ing with wet well converted to influent channels. Access by stairways. New electrical control room above ground. 10 Section 5 Variable speed, matched flow pump- $ 29,859 (Balboa Island) ing. Increase pump room size to provide legal space for electrical controls. Convert wet well to influent channel. Stairway to pump room. 11 Diamond St. Fixed speed, matched flow pumping: $ 13,729 Convert wet well to influent channel. Stairway to Pump Room. Revise electrical system. i 12 Harbor Island Pneumatic Ejector. Convert wet $ 8,027 well to manhole. Stairway to pump room. Replace electrical equipment. 13 Carnation Ave. Pneumatic Ejector: Convert wet $ 7,908 well to manhole. Construct stair- way. -1- 3 • • Plant No. Name Proposed Improvements Estimated Cost 14 China Cove Pneumatic Ejector. Replace existing $ 8,542 access shaft with 6 foot square chamber to above ground level. Provide hatch cover and ships ladder. Abandon existing wet well and con- struct new inlet manhole. 15 Buck Gulley Variable speed, matched flow pumping. $ 21)946 Convert wet well to influent channel. Ships ladder and doorway access to pump room. Extend motor room (above ground) to provide legal space for electrical controls. 16 Shore Cliffs Pneumatic Ejector. Convert wet well $ 7,231 to manhole.' Replace 2 foot access manhole with 5' -6" square chamber to sidewalk level including hatch cover and ship's ladder. Replace electrical equipment. 17 Balboa Blvd. Pneumatic Ejector. Eliminate wet 51962 well. Retain one pump as emergency stand -by. Enlarge access hatch and provide ship's ladder. 18 Main Beach* Retain existing pumps. Minimize $ 2,020 detention period in wet well. Enlarge access hatch and provide ship's ladder. Replace electrical equipment. 19 Collins Island* Minor modification by City Forces None Total Estimated Contract Cost for Proposed Improvements...$ 135,675 * See explanitory statement on Page 3 of this report. A more detailed breakdown of proposed items of work and estimated costs for each plant is provided in a book of pumping plant data which has been com- piled and turned over to the Director of Public Works. The electrical item in each estimate has been provided by the City and a copy of a report is attached to the back cover of the book. This data book also contains a record of the determination of present and projected sewage flows, and the graphs and calculations necessary to determine capacity of the major items of equipment recommended. In addition, the Director of Public Works has been furnished a set of prints of the existing plants, on which has been sketched in red pencil, the major items of the proposed improvaments. -2- k. EiiliAN AND =EENTS ON RECOMENDATIONS (A) Plants No. 6 (Bay - Island) and No. 19 (Collins Island) Plant No. 6 is too small to allow installation of an ejector as recommended in other plants with very low sewage flows.- A satisfactory new plant would involve costs in the order of $10,000. Since the sulfide and odor conditions are not critical and access is good, it is recommended that only the following work be done at present: Reduce wet well detention by lowering the levels of "on" and "off" controls as much as feasible and providing an air release opening in the pump volute to prevent air binding. The same comments apply to the Collins Island Plant (only one house served at present), except that the access is not satisfactory and that the air release must be piped back to the wet well. Also, periodic flushing with fresh water is recommended. (B) Plants No. 11 (Diamond St.). No. 7 (Lido Isle) and No. 15 (Buck Gulley) Plant No. 11 is the only location where "Fixed Speed, Matched Flow" pumping is recommended. This system is much less expensive and simpler than the variable speed drive, which is the commonly accepted solution for matched flow pumping. To the writer's knowledge it has been done only with "Torque Flow" pumps and, only as test operations. However, the conditions of low head and not extreme variation between high and low flows at this location are favorable for use of this system. A similar installation is presently being made by Orange County Sanitation Districts and one is being designed by Los Angeles County Sanitation Districts. Also, the pump manufacturer is making a series of tests which should provide definite data on this system of operation. Should further favorable experience with this system of pumping be available in time, it could be used in the final design of Plants 7 and 15 instead of the variable speed drives recommended. (C) Plant No. 10 (Section 5) The recommendation for variable speed drive in Plant No. 10 is firm, since the flow is large enough to justify a conventional centrifugal pump and the use of a Torque Flow flow pump would require the use of 30 H.P. motors as against 15 H.P. for the conventional pump. (D) Plant No. 18 (Main Beach) .Plant No. 18 has a wide range from high to low flow and the head is too high for practical use of an ejector as it would require a 30 H.P. compressor. Also, 'a variable speed drive would not be economically justified by the small flows involved. —3— '�L • 0 Further, a reasonable projection of future flows cannot be made until the nature of the future beach development is decided. For the above reasons no change in pumping is recommended at present in connection with the work proposed. VENTILATION It is recommended that all dry wells be provided with continuous ventila- tion at a rate of about 10 changes of air per hour. ACKNOWLEDGEMNT The writer wishes to express thanks for the excellent cooperation and assistance extended by the Director of Public 'Works and his staff in obtaining the data necessary for the preparation of this report. Respectfully submitted, Jo ph Kellogg e vil Engineer July 11, 1957 JKRsps F M July 11, 1957 REPORT ON SEWAGE PUMPING PLANTS THE CITY OF NEWPORT BEACH, CALIFORNIA including RECOMMENDATIONS FOR IMPROVEMENTS and ESTIMATED CONSTRUCTION COSTS C� By: Joseph Kellogg Rice Civil Engineer C. 0UTTEORIZ ATION AND PURPOSE • The City Council on June 10, 1957 authorized the employment of the writer to make a survey and report on the City's sewage pumping plants, with recommends- tions for improvements and estimated costs thereof. The principal purposes of the survey were: A. To de-..ermine means of eliminating undue detention of sewage in wet wells as a part of the City's efforts to prevent build up of sulfides in its sewer lines and coincidentally reduce odor nuisance. B. To make a preliminary estimate of costs involved. However, progress of the survey indicated desirability of increasing the scope of the proposed work to provide better access to the plants, safety measures, and improved working conditions for maintenance forces. RECOMMENDATIONS AND ESTIMATED COSTS The following tabulation gives a brief description of the major improve= ments recommended to each plant together with a preliminary estimate of costs involved on a contract basis. Plant No. Name Proposed Improvements Estimated Cost 6 Bay Island* Minor Modifications by City Forces $ None 7 Lido Isle Variable speed, matched flow pump- $ 30,451 ing with wet well converted to influent channels. Access by stairways. New electrical control room above ground. 10 Section 5 Variable speed, matched flow pump- $ 29,859 (Balboa Isla_id) ing. Increase pump room size to provide legal space for electrical controls. Convert wet well to influent channel. Stairway to pump room. 11 Diamond St. Fixed speed, matched flow pumping. $ 13,729 Convert wet well to influent channel. Stairway to Pump Room. Revise electrical system. 12 Harbor.Island Pneumatic Ejector. Convert wet 8,027 well to manhole. Stairway to pump room. Replace electrical equipment. 13 Carnation Ave. Pneumatic Ejector. Convert wet 7,908 well to manhole. Construct stair- way.. -1- 0 0 .Plant No. Name Proposed Improvements Estimated Cost 14 China Cove Pneumatic Ejector. Replace existing $ 8,542 access shaft with 6 foot square chamber to above ground level. Provide hatch cover and ships ladder. Abandon existing wet well and con- struct new inlet manhole. 15 Buck Gulley Variable speed, matched flow pumping. $ 21 946 Convert wet well to influent channel. Ship's ladder and doorway access to pump room. Extend motor room (above ground) to provide legal space for electrical controls. 16 Shore Cliffs Pneumatic Ejector. Convert wet well $ 72231 to manhole. Replace 2 foot access manhole with 5' -6" square chamber to sidewalk level including hatch cover and ship's ladder. Replace electrical equipment. 17 Balboa Blvd. Pneumatic Ejector. Eliminate wet S 52962 well. Retain one pump as emergency stand -by. Enlarge access hatch and provide ship's ladder. 18 Main Beach* Retain existing pumps. Minimize S 22020 detention period in wet well. Enlarge access hatch and provide ship's ladder. Replace electrical equipment 19 Collins Island* Minor modification by City Forces None Total Estimated Contract Cost for Proposed Improvements ... $ 135,675 * See explanitory statement on Page 3 of this report. A more detailed breakdown of proposed items of work and estimated costs for each plant is provided in a book of pumping plant data which has been com- piled and turned over to the Director of Public Works. The electrical item in each estimate has been provided by the City and a copy of a report is attached to the back cover of the book. This data book also contains a record of the determinm tion of present and projected sewage flows, and the graphs and calculations necessary to determine capacity of the major items of equipment recommended. In addition) the Director of Public Works has been %furnished a set of prints of the existing plants, on which has been sketched in red pencil, the major items of the proposed improvements. -2- EXPWAON AND CONIMNTS ON RECONMENDATOS (A) Plants No 6 (Bay Island) and No 19 (Collins Island) Plant No. 6 is too small to allow installation of an ejector as recommended in other plants with very low sewage flows. A satisfactory new plant would involve costs in the order of $10,000. Since the sulfide and odor conditions are not critical and access is good, it is recommended that only the following work be done at present: Reduce wet well detention by lowering the levels of "one' and "off" controls as much as feasible and providing an air release opening in the pump volute to prevent air binding. The same comments apply to the Collins Island Plant (only one house served at present), except that the access is not satisfactory and that the air release must be piped back to the wet well. Also, periodic flushing with fresh water is recommended. (B) Plants No 11 (Diamond St) No. 7 (Lido Isle) and No. 15 (Buck Gulley) Plant No..11 is the only location where "Fixed Speed, Matched Flow" pumping is recommended'. This system is much less expensive and simpler than the variable speed drive, which is the commonly accepted solution for matched flow pumping: To the writer's knowledge it has been done only with "Torque Flow" pumps and, only as test operations. However, the conditions of low head and not extreme variation between high and low flows at this location are favorable for use of this system. A similar installation is presently being made by Orange County Sanitation Districts and one is being designed by Los Angeles County Sanitation Districts.. Also, the pump manufacturer is making a series of tests which should provide definite data on this system of operation. Should further favorable experience with this system of pumping be available in time, it could be used in the final design of Plants 7 and 15 instead of the variable speed drives recommended. (C) Plant No. 10 (Section 5) The recommendation for variable speed drive in Plant No. 10 is firm, since the flow is large enough to justify a conventional centrifugal pump and the use of a Torque Flow flow pump would require the use of 30 H.P. motors as against 15 H.P. for the conventional pump. (D) Plant No. 18 (Main Beach) Plant No. 18 has a wide range from high to low flow and the head is too high for practical use of an ejector as it would require a 30 H.P. compressor. Also, a variable speed drive would not be economically justified by the small flows involved. —3— 0 0 Further, a reasonable projection of future flows cannot be made until the nature of the future beach development is decided. For the above reasons no change in pumping is recommended at present in connection with the work proposed. VENTILATION It is recommended that all dry wells be provided with continuous ventila- tion at a rate of about 10 changes of air per hour. ACKNOWLEDGEMENT The writer wishes to express thanks for the excellent cooperation and assistance extended by the Director of Public Works and his staff in obtaining the data necessary for the preparation of this report. JKR:ps Respectfully submitted, Jo eph Kellog �ce Civil Engineer July ll, 1957