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HomeMy WebLinkAbout01/02/1990, C-12 - EMERGENCY REPAIR OF ROCKVIEW LIFT STATION WET WELL IIIc II �IMEETING DATE: I��M������IYpllllllfll�=ullllulll C'Ity of SAn LUIS OBISPO J January 2, 1990 COUNCIL AGENDA REPORT ITEM NUMBER: -/ William T. Hetland, Utilities Director WT o[ SUBJECT: Emergency Repair of Rockview Lift Station Wet Well RECOMMENDATION: Adopt resolution waiving Purchasing Control Guidelines and authorizing the City Administrative Officer to contract for the emergency repair of the Rockview Lift Station Wet Well BACKGROUND: Attached is a CAO Special Report requesting approval of emergency repairs of the Rockview Lift Station. After the failure of the Laguna Lift Station occurred, resulting in the discharge of raw sewage for four days to adjacent fields and emergency repair costs of over $100, 000, City staff inspected the other wet wells to determine their condition. All the wet wells were satisfactory except for the Rockview Lift Station. Hydrogen sulfide corrosion has eaten away the concrete exposing the reinforcing steel. Failure of this wet well may occur at any time. The City Attorney has determined the CAO does not have the authority to approve an emergency contract under the City Charter and the City Council must make that determination with a 4-5 vote. Two firms submitted proposals to perform the necessary repair work. Staff is recommending that the firm of Advanced Manhole Technology be retained even though their contract amount is larger. Their proposal included bypass pumping and a greater sensitivity to the safety needs for this job than the other proposing firm. ALTERNATIVES: Two alternatives are available to the City. The first is to approve by a 4-5 vote, the attached resolution and make the repairs under an emergency contract. The second alternative is to direct staff to develop detail plans and specifications and follow the normal Council approval and bidding procedures. This alternative would require an additional 4 to 6 weeks. Because of the deteriorating condition of the wet well, staff does not feel it is prudent to delay this repair work further and does not recommend this second alternative. CONSEQUENCES OF NOT TAKING THE RECOMMENDED ACTION: If immediate action is not taken, there is a greater risk the lift station wet well will fail resulting in the potential of raw sewage being discharged into the creek and subsequent fines from the California Regional Water Quality Control Board. Additional biz-/ ������i�►►�Iillllllll�►°�9�1111 city of san tuts osispo COUNCIL AGENDA REPORT Rockview Lift Station Wet Well January 2 , 1989 Page 2 costs would also be incurred if an emergency repair was required after failure. FISCAL IMPACT: The estimated cost is $30, 000 for the contract and miscellaneous City expenditures for the repair. RECOMMENDATION: Adopt resolution waiving purchasing control guidelines and authorize the City Administrative Officer to contract for the emergency repair of the Rockview Life Station Wet Well. WTH:bja Attachment: CAO Special Report Draft. Resolution rockview.wp Cl102-2 RESOLUTION NO. (1990 Series) 'I A RESOLUTION OF THE COUNCIL OF .THE CITY OF SAN LUIS OBISPO APPROVING EMERGENCY REPAIR OF THE ROCKVIEW LIFT STATION WET WELL WAIVING PURCHASING CONTROL GUIDELINES AND AUTHORIZE CAO TO APPROVE CONTRACT WHEREAS, the City staff has inspected the Rockview Lift Station Wet Well; WHEREAS, the inspection has determined the wet well in need of immediate repair; WHEREAS, the immediate need of repair is determined to .be an emergency situation and; WHEREAS, the Council may waive the City's Purchasing Control Guidelines and direct staff to enter into an emergency repair contract. NOW THEREFORE, BE IT RESOLVED the City Council determines that the Rockview Lift Station Wet Well is .in an emergency state and they waive the Purchasing Control Guidelines and authorize the City Administrative Officer to approve a contract for the emergency repair of the Rockview Lift Station Wet Well. On motion of , seconded by and on the following roll call vote: AYES: NOES: ABSENT: the foregoing resolution was passed and adopted this day of 1990. MAYOR RON DUNIN ATTEST: CITY CLERK PAM VOGES- APPROVED: CITY ADMINIST TIVE OFFICER FI - DIRECTOR UTILITIES DIRECTOR city of sa►r _-'U1S OBISPO C.A.O. SPECIAL RWPORT FROM: William T. Hetland ` Prepared by: John E. Moss Utilities Director Wastewater Division Manage / SUBJECT: Rockview Lift Station Wet Well, Emergency Repair CAO RECOMMENDATION: Authorize staff to enter into agreement with Advanced Manhole Technology for emergency repair/lining of the Rockview Lift Station Wet Well. BACKGROUND: In July 1989 the Laguna Lift Station wet well collapsed due to severe sulfide corrosion of the concrete. Subsequent to the collapse of the Laguna Lift Station wet well, city collection system crews were directed to perform a video inspection of the remaining seven lift station wet wells. The remaining wet; wells were found to be in satisfactory condition with the exception of the Rockview wet well. Video inspection of the Rockview wet well showed the sulfide corrosion of the concrete has extended beyond the reinforcing bar in the concrete. City engineering staff concurs that the wet well is in a state of collapse and has little or no remaining structural integrity. Staff is concerned that with the rapid approach of the rainy season the water table will be rising and placing additional hydrostatic load on the wet well. For this reason, staff is recommending repair/lining of the wet well be performed as an emergency repair project. Two pipe lining contractors were contacted to provide the City with proposals for installation of a PVC liner. Engineering is satisfied that this type of repair would suit the needs of this project. Advanced Manhole technology has submitted a proposal for lining of the wet well at an estimated cost of $25, 650. 00. Their proposal includes all required work to complete the repair. In addition to the work that is proposed, City engineering staff recommends including a reinforcing bar cage be installed in the grouted portion of the wet well. This is estimated to add approximately $3 , 000 to the total project cost. Rondeau Bay Construction, Inc. has also submitted a proposal for lining of the wet well at an estimated cost of $12 , 337 . 00. The proposal from Rondeau Bay does not include much of the work proposed by Advanced Manhole Technology. The work not City Of S. I IU1S 0131SPO C.A.O. SPECIAL REPORT CAO SPECIAL REPORT Rockview Wet Well Emergency Repair Page 2 included would have to be performed by city crews. Also Rondeau Bay proposes to simply line the top cone section of the wet well , rather than full replacement. Staff also has concern regarding safety with Rondeau Bay' s proposal. With their method of lining, both staff and contractor personnel would be required to enter the wet well during the cleaning and Einer installation phases. Staff is concerned that should the wet well collapse during this time, serious injury or even death could result. With the extent of corrosion present in the wet well staff feels that it should be treated as an unshored excavation and should not allow personnel entry. The methodology proposed by Advanced Manhole Technology allows construction of the forms and liner above ground. These can then be lowered into the wet well prior to entry by contractors personnel . The forms would be sufficient to act as shoring in the event the wet well should collapse. Staff feels that should Rondeau Bay Construction perform all of the work proposed by Advanced Manhole Technology and meet all of the required safety and shoring needs of the project, their proposed cost estimate would be comparable to or greater than Advanced Manhole Technology's. Staff also has greater confidence that the methodology proposed by Advanced Manhole Technology would provide the City with a satisfactory end product and a safe and trouble free construction project. FISCAL IMPACT: During the conceptual phase of this project, $90, 000 was allocated for repair of the wet well. The funding was to be taken from a lower priority CIP project approved in the budget process. The proposal from Advanced Manhole Technology was for a lump sum amount of $25, 650. Allowing an additional $3 , 000 for inclusion of a reinforcing bar cage the total amount would be $28 , 650 . Staff is confident based on the above information that the total project cost will not exceed $30, 000. Emergency repair of the Laguna Lift Station wet well after collapse totaled $116, 444 . 46. This request for emergency repair of the Rockview wet well follows the guidelines established in section 404-2 of the Purchasing Control Manual. Council approved funding in the 1989-91 financial. plan, (page E-7) "Replacement of Sewer Collection Mains" . RECOMMENDATION: Authorize staff to enter into agreement with Advanced Manhole Technology for emergency repair/lining of the Rockview Lift Station Wet Well. Maize S7 PEC IAL REPURT CAO SPECIAL REPORT Rockview Wet Well Emergency Repair Page 3 �� Approved: ohn Din,City Administrative Officer Jeff Jorgensen, City Attorney William Statler, Finance Director William T. Hetland, lJtilities Director I J Moss, Waste titer Division Manager I I • I Date i Attachments: Rondeau Bay Construction Inc. Proposal Advanced Manhole Technology Proposal i rvwwcao.wp i Rondeau Bay Construction, Inc. 1177-5TH STREET,OAKLAND, CA 94607 General Engineering Contractor Phone (415)268-1505 Fax(415) 834-1528 November 16, 1989 C.S.C.L No.537524 Mr. Gary Henderson, Engineer CITY OF SAN LUIS OBISPO 25 Prado Road San Luis Obispo, California 93403 Fax # (805) 549-7198• re: Rock-.View Lift .Station-.Rehabiliiation'­_ Dear Mr. Henderson: Rondeau Bay Construction greatly appreciates your time and consideration of the Danby PVC lining system for use in your District. Per our conversation, please find enclosed the draft specification section for our lift station PVC liner system. In addition to the method outlined in the enclosed specification it is possible to add structural steel in the annular space to enhance the structural characteristic of the lined lift station. Per your instructions we have estimated utilization of a No. 3 rebar cage on a 1 ft. x 1 ft. layout. This will result in an approximate 2 inch wall thickness and 4 inch reduction in inside diameter. For the concentric shaped dome of the lift station we will utilize ferro cement with an Amoron Armor-Plate PVC liner. Our estimate is as follows: Rehab lift station with rebar Cage . . . . . . . . . $12, 337.00 Rehab lift station without rebar Cage . . . . . . $ 91889 .00 Our estimates includes lining the base of the lift station if this is not needed please deduct $600. Our estimate excludes any cleaning, diverting or pumping that may be required. We are anxious to perform' a demonstration of the Danby system in your district .and ..look forward to performing your proposed lift station rehabilitation .project. r Mr. Gary Henderson November 161 1989 Page 2 1 U c iaa5es uu iiu% iitsitaLe to contaCL me iz you Would like additional information. Sincerely, : RONDEAU BA CONSTR ION, INC. �i Alan E. Dones' . C.O.O. AED:ml C Draft Specification for Manhole and Wet Well Rehabilitation 1. General This specification applies to the requirements for rigid polyvinyl chloride (PVC) extrusions and grout used for the rehabilitation of manholes and wet wells. The PVC is a lining material which acts as a protective barrier and a form for the grout. The grout which fills the annular space supports the liner and fills any voids in the existing structure. 2. Materials 2.1 Plastic Liner The plastic extrusions, including the forming strips, and panels shall be manufac- tured from high molecular weight polyvinyl chloride compound. Fillers shall not exceed 10%by weight of PVC resin in the compound. Changes in the formulations will be permitted only after prior notice is given to the engineer and the manufacturer, demonstrates that the new plastic material will meet or exceed all requirements Cspecified herein for mechanical resistance and physical properties. 2.2 Chemical Resistance and Physical Testing The Engineer may, at any time, direct the manufacturer of the plastic extrusion to obtain compound samples and to prepare test specimens in accordance with ASTM D1784 . These specimens shall comply with the minimum property values of the applicable ASTM requirements. 2.3 Design and Detail The structure shall be lined with plastic former panels which are capable of being. bent around the circumference of the structure. The edges of the panels shall incorporate a male and a corresponding female lock which interengage when overlapped. The outer surface shall incorporate ribs and the inner surface shall be smooth and free of blemishes. The end joining piece shall be shaped so it fits tightly between the ribs of the forming section and overlaps the edges. 2.4 Grout The grout shall consist of, but not limited to, any or all of the following: Type II Portland Cement;water;flyash;admixtures; and bentonite clay. Proprietary brands of premixed lightweight grouts shall be used in accordance with the manufacturers instructions. The type of grout and the application procedures used to inject the grout shall be approved by the Fnoinaar nrinr rn i 2.5 Adhesive Materials The adhesive products and application procedures used in the installation of the liners shall be approved by the Engineer prior to use. PVC solvent cements shall conform to ASTM D2565. 3. Liner Installation 3.1 Preparation The structure walls, base, step irons and protruding pipework shall be thoroughly cleaned of all grease, slime and loose or soft concrete by pressure washing. Any large solid protrusions on the wall surface such as mortar lumps shall be removed with a small sledge or chipping hammer. Mortar around protruding pipes shall be cut back as near as possible to flush with the existing wall surface. Infiltration through the existing structure which would adversely affect the installation of the panels or the grout material should be eliminated or reduced to an acceptable level. 3.2 Bypass Bypass, if required, shall be accomplished by standard methods or as directed by the Engineer. Under normal conditions flows need only be controlled while working as the base of the structure. 3.3 Safety The contractor shall, at all times, practice standard safety procedures and shall be subject to those safety regulations and policies set forth by local, state, and federal authorities. 3.4 Panel Installation The panels shall be cut and trimmed to fit as near as practical to the internal diameter of the structure. The panels shall be placed commending at the base with the female I - � locking edge on the upper edge of the panel. A bead of adhesive_shall be applied to the female locking edge and the end joining piece prior to the locks being engaged. The locks hall be snapped home with a rubber rnallet. Metal hammers and undue force should not be used. End joints shall be made with a plasticized end joining section which shall under-lap the panels by not less than there inches (3°). The end joints shall be staggered so was the joints are not aligned. Should the end joiner open, then they shall be caulked and patched with a piece of PVC. Panels that cannot be completely joined together shall be pinned to the existing wall with nylon masonry anchors. If necessary, the panels can be shimmed off the walled to avoid discontinuities on the surface. 3.5 Sealing the Liner Panels shall be cut to fit as neatly as possible around protrusions. At the base around protrusions the panels shall be sealed with an approved sealing compound. The type and method of application shall be approved by the Engineer prior to use. 3.6 Grout Injection CGrout materials shall be mixed thoroughly in paddle, pan, or colloidal mixer, Grout shall be injected behind the liner either by tubes placed behind the panels orthrough holes drilled into the plastic. Tubes placed behind the liner shall extend to the bottom of the liner. If possible, the tubes should be extracted during the grout injection. Grout tubes which remain fixed should not be used to completely fill around the liner. Grout placement shall be slow and uniform so as the grout pressures do not cause buckling or distortion of the plastic liner. Holes and leaks in the liner shall be sealed and covered with a patch of similar material. Grout injection should be a continuous operation as far as practical. Should the operation be interrupted, the in place grout tubes should be abandoned and grouting shall recommence through holes drilled in the liner. 3.7 Clean up The contractor shall leave the area in good and tidy condition. All rubbish shall be removed from the area and properly disposed. �l • ADVANCED = r MANHOLE TECHNOLOGY STRUCTURAL MANHOLE RECONSTRUCTION December 5, 1989 City of San Luis Obispo Public Works Department 990 Palm St Box 8100 San Luis Obispo, CA 93403-8100 Attn: Mr. Gary Henderson Re: Wet Well Rehabilitation Gentlemen: We are pleased to quote on the wet well project and are confident our expenditous and effective method of rehabilitation will satisfy your needs. For the lump sum amount of ($25650.00) twenty five thousand six hundred fifty dollars_ and no cents we will provide all labor, material & forms to set in place a monolitic cement structure with T-lock P.V.C. lining from the water level at the base of the wet well to the ground surface, including the placement of the manhole frame & cover. All cleaning, surface preparation, bypass (internal) , and cone removal are included. Traffic control, safety barricades, and lighting as required are included as well. Strict adherence to State, Federal, Local, Osha. and Cal 0sha safety regulations will be followed. We will provide constant air monitoring, tripod manlift, fresh air ventilation, and all standard safety protection equipment including hard hats, goggles, ear protection, harnesses, gloves, etc. Excluded in our quote is the maintenance of the sewage level which is to be handled by your departments forces. Should your forces accomplish the removal of the cone section and the protective pipe barriers surrounding the wet well please deduct the sum of ($3660.00) three thousand six hundred sixty and no cents. truly yours, on Owe 3402 Budleigh Dr. . Hacienda Heights, Calif. 91746 Tel. (818) 369-7011 ADVANCED MANHOLE C TECHNOLOGY STRUCTURAL MANHOLE RECONSTRUCTION Specifications for Monolithic Reconstruction of Manholes (3-1-89) I-1 _ Intent It is the intent of this specification to provide for the reconstruction of manholes by temporarily erecting a forminside an existing manhole and filling the annular space between the erected form and the existing manhole wall with concrete or other approved materials that will result in a new monolithic manhole within the old one. I-2 Materials Unless otherwise specified, concrete shall be used to fill the annular space. The newly formed interior surfaces shall be protected with plastic liner sheets. I-3 Concrete : The concrete mix shall be Class 560-C-3250 with a Test Grading C coarse aggregate. The slump may be increased to facilitate proper placement in the field. I-4 Plastic Liner : All. plastic liner sheet materials and installation shall comply to the applicable requirements of the "Standard Specifications for Public Works Construction" 1985 Edition, Sections 210-2 and 311.1 unless shown otherwise on the drawings or in these specifications. -/� /3 The Plastic liner, polyvinyl chloride T-Lock, shall be manufactured by Ameron, Brea, California (714) 529-1951, or approval equal. 1-5 Thickness : The new monolithic walls shall be approximately three (3) inches thick. Wall thickness .may vary due to offset shafts or unusual manhole configurations; however, the contractor will endeavor to position the forms to provide equal wall thickness. I-6 Manhole Preparation The manhole walls and base shall substantially be made free of loose debris by brushing or. pressure washing. Steps or obstructions that prohibit proper erection of the interior frame work shall be removed. Infiltration through existing manhole walls that "would adversely affect the material used in the annular space shall .be eliminated or reduced to an acceptable level. I-7 Bypass Bypass, if required, shall be accomplished by standard methods or as directed by the engineer. Under normal conditions flows through the manhole shall be maintained by placing temporary sleeves between the invert of entry and exit piping which shall be removed upon completion. Sleeves installed in inlets, drops, cleanout, laterials, and existing piping between theexisting wall and the temporary forms may be left in place. I-8 Safety : The contractor will at all times practice standard safety procedures and shall be subject to those safety regulations and politices set forth by local, state, and . federal authority.. L-9 Traffic Control The contractor shall establish traffic control .utilizing standard warning devices such as cones and barricades as condition_s warrant and shall comply with local and state regulations. I-10 Installation After complying with items I-6 through 1-9 the contractor shall Cestablish a base course of calcium aluminate cement on the shelf of the manhole that serves to substantially level and seal the forms to be erected. Once that base framework has been set, additional panel sections shall be hand assembled with nuts and bolts to form riser and reducer sections that substantially fit the interior shape and size of the manhole while leaving an approximate three (3) inch annular space between the old wall and the new form. Plastic liner sheets shall be installed and secured to the forms prior to the filling of the annular space. Locking extensions are required and shall be placed vertically except at conical sections where they may vary to meet curved surfaces. Gaps between the adjacent plastic liner sheet sections shall be a maximum of two (2) inches. Redi-Mixed concrete or other approved materials, to the owner's specifications, . is then poured into the annular space filling voids, sealing leads, and eliminating joints. After the concrete or approved material has set, usually a few hours, the panels are removed one by one and hauled up through the existing opening. ' I-11 Field Jointing of Liner Field Joints in plastic liner sheets shall be one of the following: 1) Type C-2 joint shall consist of a centered one (1) inch flat weld strip secured to adjacent liners wherever the gap between liners is 1/4 inch maximum, or shall consist of a centered two (2) inch flat weld strip secured to adjacent liners wherever the gap between liners is between 1/4 inch and 1 inch. 2) Type C-1 joint shall consist of a centered 4-Inch joint strip of 2" x 2" Angle Strip wherever the gap between adjacent sheets exceeds one inch-or a conical section deflection angle doesnot allow the use of weld strips. Each edge of the strips shall be secured to the adjacent liner by means of a welding strip. Welding shall be performed by those certified by the manufacturer of the liner. 3) When installation is complete, the. entire lining, including weld areas, shall be cleaned for visual inspection and tested with a high. voltage pinhole or holiday detector to the requirements of the C, "Standard Specifications for Public Works Construction" Subsection 210-2.3.6. Any imperfections must be repaired before placing the reconstructed manhole in service. I-12 Clean Up The contractor shall leave the work area in as good as or better condition than when the work was commenced.. I-13 _ Payment The payment shall be based on a predetermined unit cost per vertical foot or lump sum and shall be due and payable within forty five (45) days of completion. 4061D l � 11/89 SECTION 313 - MANHOLE AND STRUCTURE REHABILITATION MATERIALS AND METHODS 313-1 General. This section covers the various approved manhole and structure rehabilitation materials • and methods. The type(s) of rehabilitation materials and methods for a given project shall be designated on the Plans. The Engineer may require testing of the materials and methods for compliance with these requirements prior to delivery to the job site and/or prior to acceptance depending upon the alternate selected. 313-2 Manhole Preforming System 313-2. 1 General. This Subsection describes the installation of the Integral Locking PVC Liner by temporarily erecting a form inside an existing manhole and filling the annular space between the erected form and the existing manhole wall with concrete or other approved. materials that will �) result in a new PVC lined monolithic manhole within the old one. This work is for sanitary sewer manholes. The same preforming system can be utilized for storm drain manholes, except when indicated on the plans .or special provisions, the PVC liner may not be required. 313-2 .2 Concrete. Concrete, unless otherwise specified by the engineer, shall be Class 560-C-3250 per Subsection 201- 1. 1.2. 313=2. 3 Integral Locking PVC Liner. The liner shall comply with the applicable requirements in Sections 210-2 and 311. 1 unless shown otherwise on the plans or specifications. 313-2. 4 Chemical Resistance and Physical Testing. The Integral Locking PVC Liner shall meet the requirements of Sub- section 210-2.3 11/89 313-2.5 Installation and Field Inspection. The manhole walls and base shall be free of loose debris by brushing or low pressure washing. Steps or obstructions that prohibit proper erection of the interior formwork shall be removed to a depth of 1 inch minimum inside the structure. The formwork shall be installed in a manner that substan- tially fits the existing walls of the manhole and creates an equal and approximate three (3) inch annular space. Concrete or other materials, as indicated on the plans or special provision, shall be used to fill the annular space. The installation of the Integral Locking PVC Liner shall comply with Section 311-1. 313-2.6 Service Connections. Existing lines to the manhole shall be extended through the newly formed manhole wall. The exposed concrete surfaces within the manhole shall be protected as indicated on the plans or special provi- sions. 313-3 Manhole Liners 313-4 Linings and Coatings • 313-5 Chemical Grout 313-5. 1 General. Chemical grouts shall consist of a mixture of three or more water soluble chemicals which produce stiff. gels from properly catalysed solutions. The reaction in the solution may be either chemical or physiochemical producing a solid precipitate. Chemical grouts are used to seal deteriorated and leaking pipe joints, service connection joints, open joints, manhole and structure joints and/or cracks. The cured sealant formation shall. be chemically stable and resistant to the concentration of acids, alkalis, and organics found in normal sewage. The sealant formation shall not be biodegradable. 313=5. 2 Material Composition. The acceptable generic listing of chemical sealing materials and concentrations shall ' be. used as follows: 12 • PROBLEM MANHOLES REPLACE WITHOUT EXCAVATING 'Advanced Manhole Technology , POUR A NEW MONOLITHIC �1 T CONCRETE MANHOLE :.. INSIDE THE OLD ONE PERMANENTstructurally sound and leak-free STRONG :. DURABLE FAST even deep ones are rebuilt in one day w LEAK-FREE VERSATILE fits a variety of sizes and depths BIG savings over other methods ECONOMICAL " �'� NEW 3" CONCRETE CONVENIENT sewer lines and drops remain open wALr`• L h STOPS LEAKS! SAVES STREETS! 'ACID-RESISTANT CONCRETE OR T-LOCK LINER CAN BE USED FOR AREAS OF HIGH SULFIDE CORROSION. RE-LINED BRICK MANHOLE Advanced Manhole Technology, Inc. • 3402 Budleigh Dr. 9 Hacienda Heights, Calif. 91745 t �~ After the manhole is pressure washed* -° to remove loose pieces, reusable lightweightsteel panels are lowered to the workman inside. . fir.• r t' Panels are hand-assembled with bolts and nuts to form riser and reducer sections that fit the interior shape and size while leaving a T' space _ between the old wall and the new form Redi-mixed concrete to the city's specifications is then poured into this space filling voids, sealing leaks and eliminating joints. 12 foot deep �- manholes commonly use less than 2 cubic yards. special inserts placed in the active lines allow uninterrupted sewer flows, even in ones with drops P.; After the concrete sets in a few hours the panels are removed one by one and handed up through the existing opening ready for their next use and leaving . . . . ,�