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HomeMy WebLinkAbout12 Airport Water Tank Agenda Item # 12 Public Utility District ACTION To: Board of Directors From: Mark Thomas Date: May 05, 2010 Subject: Consideration of Action Regarding the Airport Water Tank a) Adopt a Resolution Declaring an Emergency with Respect to the Airport Water Tank and Dispensing with Competitive Bidding to Refurbish the Tank b) Award a Contract to Refurbish the Airport Water Tank 1. WHY THIS MATTER IS BEFORE THE BOARD Only the Board can declare an emergency and dispense with the competitive bidding process. Board approval is required for expenditures in excess of$15,000. 2. HISTORY The Airport Water Tank was built in 1979 by Crom and is a 600,000 gallon unit constructed of prestressed concrete. The dome ring which supports the tank roof is failing and needs immediate repair. The tank plays a critical role in the water distribution system. The Airport Well is the system's largest producing well and is dependent upon this tank to produce. 3. NEW INFORMATION With the high water demand season upon us, we cannot afford to lose this source. A bidding process would delay the repair work for 3 to 4 weeks. DYK Incorporated is one of the few companies in the United States that specializes in construction and repair of prestressed concrete tanks. Staff contacted DYK about the Airport Water Tank. Design and repair costs were negotiated at $115,253. DYK stated repair work on the tank could begin by the middle of May 2010 and be completed by the end of June 2010. The entire scope of this repair is described in DYK's proposal included as Attachment 1. As an alternative to performing the repair, a new tank could be constructed in the same general area as the existing tank. This tank would be smaller, approximately 100,000 gallons, and would cost from $200,000 to $250,000 including design, geophysics, demolition of old tank, and new construction. The estimated time to complete the new construction would be December 2010. 4. FISCAL IMPACT There are sufficient funds in the 2010 Water Capital Reserve Fund. 5. RECOMMENDATION a) Adopt a Resolution (Attachment 2) declaring an Emergency with respect to the Airport Water Tank and dispensing with competitive bidding to repair and refurbish the tank. b) Award DYK Incorporated the contract for the design and the repair for the Airport Water Tank in the amount of $115,253 plus a 10 percent change order allowance for an amount not to exceed $126,778. c) Authorize a transfer of up to $126,778 from the Water Capital Reserve Fund to the Water General Fund. Michael D. Holley General Manager/ Water Utility Manager Attachment 1 ,' RA. , � w . ADDRESS: 351 CYPRESS LANE EL CAJON, CA 92020 • MAILING: P.O. BOX 696 • EL CAJON, CA 92022-0696 PHONE. (619) 440-8181 • FAX: (619) 440-8653 • WEB: WWW.DYK.COM • EMAIL: DYKINCC&DYK.COM April 19, 2010 Mr. Mark Thomas Mr. Michael Holley Truckee-Donner PUD P.O. Box 309 Tuckee, CA 96160 600,000 Gallon Airport Reservoir Truckee, California Dear Gentleman: Attached you will find our revised proposal to restore the dome prestressing for your Airport Reservoir to its original as built conditions. As you know, we have been hampered by the lack of information regarding the original design. We understand you inherited the tank as part of the takeover of another system and the only records that exist is one drawing containing just generic details with very limited real structural information. Based on this limited information and our conversations, we believe the following information is correct: • The tank has an inside diameter of 70'-0" and a water depth of 18'-0". • The tank has a concrete free span dome which you measured as 3" thick. The roof was most likely reinforced with #3 or #4 bar in each direction which would result in approximately 1" of concrete cover, top and bottom assuming the rebar was adequately supported and a uniform dome thickness was provided. You have noted that in at least one location on the underside of the dome the rebar is exposed and corroded. There is also evidence of cracking on the top of the dome although the extent of this cracking is hard to determine due to the condition of the dome coating. We would recommend a thorough examination of the underside of the dome and repair of any spalled concrete. For the top of the dome, the deteriorated coating should be tested for hazardous material, safely removed, cracks sealed, any spalls repaired and a new coating applied. This work is not included in our proposal but we can provide guidance on selection of materials for your forces to use. • The wall is most likely an AWWA D 110 Type 2 wall made of shotcrete with an integral thin metal diaphragm. The tank was most likely constructed by Crom Tanks, a now defunct company formally from Reno, Nevada. No evidence of distress on either the interior or exterior of the tank has been noted including in the area you recently excavated to work on the tank piping. We would recommend you perform a thorough investigation of the tank wall interior prior to working on the dome. This work is not included in our proposal but we can provide guidance on selection of materials for your forces to use if any deterioration is noted. N Elyffarl'330 e Mr. Mark Thomas Mr. Michael Holley Page 2 of 3 April 19, 2010 • The tank floor may be as thin as 4" and there is no distinct wall footing. Because of the thinness of the floor, limited concrete cover and rigid floor to wall connection, the floor and particularly the floor to wall connection on this type of construction have been known to have significant leakage problems in other tanks. Leakage is a concern not only for the loss of water but also because it has the potential to undermine the tank structure or lead to further deterioration. You indicated you have performed a leak test of the tank and no loss was evident. We would recommend you perform a thorough investigation of the tank floor and floor to footing connection prior to working on the dome. This work is not included in our proposal but we can provide guidance on selection of materials for your forces to use if any deterioration is noted. • As noted in the attached proposal, DYK will remove the outer layer of gunite depositing it on the ground (for your forces to remove and dispose of) that has substantially delaminated from the single wire prestressing and in some cases fallen off exposing the wire to the elements. From the sample removal you recently performed, the gunite came off easily exposing dirt and moisture trapped behind the gunite creating an ideal environment for further corrosion to occur. • Since we only have limited information on the design of the existing tank and to prevent overstressing of the dome and top of wall, after discussion with you it was decided to supply enough prestressing to restore the prestressing that has been lost due to corrosion. We are not upgrading the dome to current seismic, snow or other code requirements but only restoring the dome to the original design and attempting to slow any further deterioration. The assumptions we made in determining the correct amount of new prestressing to supply were: o Each original prestressing wire had a diameter of 0.196", an area of 0.030 square inches, a minimum ultimate strength of 250 ksi, were initially stressed to 70% of ultimate strength and had a time dependent stress loss of 25 ksi. This would result in a final force per wire of 4.5 kips. o There are 45 wires exposed in the outer layer resulting in a final force before corrosion of 202.5 kips for the outer layer. By code the minimum clearance between wires should have been 3/8" which was obviously not met. There is evidence of at least one inner layer of prestressing but the total number of layers or number of wires per layer is unknown. 0 5 bands of 0.6" diameter galvanized strand would provide a force of approximately 122.5 kips. This is equivalent to restoring up to 60% of the original prestressing lost to corrosion. With the wire currently exposed this appears to be a somewhat conservative assumption but would have to be confirmed after all of the original gunite is removed. We would also recommend carefully removing the gunite between layers at a few Y a, 4 • 4 1 Mr. Mark Thomas Mr. Michael Holley Page 3 of 3 April 19, 2010 locations around the dome to confirm the assumption that the inner layer(s) are not corroded. If we find more than 60% corrosion of the outer layer of existing wire or significant corrosion on an inner layer we may have to evaluate adding an additional layer of new banding. We appreciate the opportunity to propose on this work. If you should have any questions on the enclosed, or if we can be of further assistance,please feel free to contact us. Sincerely, William J. Hendrickson CEO DYK Incorporated NOW I! PURATED ADDRESS: 351 CYPRESS LANE • EL CAJON, CA 92020 • MAILING: P.O. Box 696 • EL CAJON, CA 92022-0696 PHONE: (619) 440-8181 • FAX: (619) 440-8653 • WEE: WWW.DYK.COM • EMAIL: DYx1NCCbDYK.COM PRESTRESSING CONTRACT PROPOSAL Date: April 19,2010 Proposal No.: 100419R License No.: 584105 To: Truckee-Donner PUD Description: 0.6 MG Airport Tank P.O.Box 309 Seismic Dome Repair Truckee,CA 96160 Location: Truckee,CA Phone: 530-587-3957 Owner: Truckee-Donner PUD Attn: Mark Thomas(markthomas(&,tdpud.org) Cc: Michael Holley(michaelholley_(&,,tdpud.orjz) DYK offers to do the following work, in accordance with the attached drawings and calculations. DYK's contract price is based on the conditions outlined hereunder. In arriving at the cost, a continuous, and an uninterrupted operation was assumed starting with the day DYK was requested to move in. DYK is bidding this project as an equal opportunity contractor. A. SERVICES FURNISHED BY DYK: 1. Design: Shop drawings and calculations indicating the identification and location of all components used in the system. 2. Scaffoldiniz: DYK shall provide and install all required scaffolding and equipment to complete its scope of work. Truckee-Donner PUD (TDPUD) shall provide a level work area 7' wide completely around the tank including ramp access. 3. Repair: Remove or repair all damaged, spalling, deteriorated or otherwise unsound existing shotcrete on dome ring. Remove all loose or failed prestressing and clean all existing prestressing. Repair cleaned areas with grout. 4. Circumferential Prestressing: Furnish and install 5 prestressing bands. 5. Shotcrete: a. Furnish and install 1/2" initial shotcrete over existing, cleaned, dome ring. Furnish and install 1.5"final shotcrete cover over prestressing bands, couplings, and conduit. b. Apply 7-day water cure upon completion of the shotcrete. Water for curing to be furnished by TDPUD. Note: DYK's bid is based on all existing coatings on the tank dome ring and dome exterior being non- hazardous. Any damaged prestressing and concrete removed from the dome ring and dome will be deposited on the ground around the tank. Any further removal or containment of the removed material(if required)will be performed by TDPUD or by DYK at an additional cost to TDPUD. TOTAL CONTRACT: $115,253.00 T..,.._......1 J1 I fin Anr►n T�---- Y e) B. SERVICES FURNISHED FREE OF CHARGE TO DYK BY TDPUD: 1. With Respect to all operations: a. TDPUD shall furnish any safety fencing that may be required by DYK or OSHA around the site. TDPUD shall be responsible for site security, including security guards. TDPUD shall be responsible for the security and well being of DYK's equipment, tools, and materials stored at the project site and shall reimburse DYK all direct costs associated for damage or loss of equipment, tools, and materials as a result of vandalism or theft. b. At all times, provide satisfactory all weather access to the tank and storage area for DYK's trucks carrying equipment and materials. If trucks and trailers are unable to safely reach the tank and storage area, the TDPUD will be liable for any towing costs, lost time, damage to our equipment, unused crane time, etc. C. Provide any shoring and dewatering necessary for a safe and efficient performance of DYK's work and in accordance with all applicable laws and regulations. d. Provide a minimum clearance of 7'-0"from outside the tank wall from grade level upward. e. Submit shop drawings of all items to be cast in or bolted to the wall and roof(before proceeding with the installation of such items) for DYK to review and approve in order that DYK may be assured that there will be no interferences with the operation of DYK's machinery. f. TDPUD shall remove prior to DYK's move in and replace after DYK's work is complete any obstructions such as the exterior ladder and handrails that prevent free access to the existing dome ring all around the tank. The anchor detail for all appurtenances including the exterior ladder and handrails shall be submitted by TDPUD to DYK for review to protect against damaging the prestressing. g. Provide a level and flat storage area within 10' from the tank large enough to store all prestressing steel, shotcrete materials and wrapping and shotcrete machinery required for that tank. The minimum dimensions of this area shall be 50' X 50'. 2. With Respect to Prestressing: a. Store the required prestressing steel within 10' from the tank. b. Due to safety requirements, no work will be done by unauthorized personnel within two hundred (200) feet of the reservoir core wall during the circumferential prestressing activities. DYK authorized personnel must approve modification to this 200'. 3. With Respect to the Shotcrete: a. Furnish potable water at 40 psi minimum pressure and 10 gpm minimum volume within 25' from the tank. b. Unless stated otherwise,cure the shotcrete as per specifications. C. Rebound will be removed from and will be deposited on the ground by DYK. Beyond the above mentioned rebound removal, if required,TDPUD is responsible. d. TDPUD shall provide and pay for all required concrete/shotcrete testing, excluding preconstruction testing required for approval of shotcrete mix designs and any re-testing during the project due to a failure on our part to achieve required results. C. PAYMENT CONDITIONS FOR MATERIALS FURNISHED AND WORK DONE: 1. Progress Payments shall be made monthly and in accordance with DYK's Progress Payment Schedule and reach DYK by the tenth (10t') of the month for materials furnished and/or work completed in the previous month. TDPUD shall withhold no greater than 5%retention. 2. Final Payment in full shall reach DYK within thirty-five (35) days from the date that DYK has physically completed its work under this Agreement. TDPUD shall give verbal or written approval of DYK's work before DYK leaves the site, in order to satisfy and insure itself that the work has been done Proposal# 100402R Page 12 to everyone's satisfaction.No final payment shall be delayed because of delays in water testing. Payment in full shall not relieve DYK from correcting faulty materials and workmanship within the specified Guarantee Period(one year). 3. Payment: All payments made by TDPUD pursuant to this contract shall be made to DYK Incorporated at P.O. Box 696, El Cajon, California 92022 and to no other party, sub contractor or supply house, unless specifically directed by DYK in writing. All such payments shall be received by DYK by the tenth(1 Oth) day of the month immediately following the work period for which billing was made. 4. Interest: Overdue payments shall bear interest of 0.05% per calendar day (18.25% per annum) on all overdue amounts, in dispute or otherwise,until paid. 5. Back Charges: Except as provided for under Par. F, there shall be no back charge of any sort by either party unless and until an authorized representative of each party has agreed to in writing the reason for and the extent of such back charge prior to such services being rendered by or for one of the parties under this Agreement. 6. Performance/Payment Bonds: If TDPUD desires DYK to furnish a performance/payment bond the charge for such bonds shall be paid directly to DYK's bonding agent by TDPUD or may be paid directly to DYK at DYK's direct cost plus ten percent(10%). 7. Substitution of Securities: TDPUD shall assist DYK in setting up an escrow account for substitution of securities in lieu of retention. Interest from this escrow account shall be payable to DYK Incorporated. 8. Insurance: DYK reserves the right to increase the contract amount of this proposal if DYK is required to participate in an Owner Controlled Insurance Program, Contractor Controlled Insurance Program, or similar program that has a higher cost to DYK than our own program. D. CONSTRUCTION TIME 1. The following is a summary of the ANTICIPATED construction time starting with the first work day following the completion day of all the services TDPUD is to provide under the above paragraphs,which time makes no allowance for weather and unforeseeable conditions (to be added by TDPUD): a. Required notice(in writing)to commence work 4 Weeks b. Repair,prestressing bands and shotcrete 8 Weeks E. TESTING: TDPUD shall provide and pay for all required materials testing, shotcrete and concrete testing(including sand and aggregate). DYK shall be responsible for any preconstruction testing required for approval of shotcrete and concrete mix designs and for any retesting during the project due to a failure on our part to achieve required results. TDPUD shall provide and pay for all inspections including overtime inspections. TDPUD shall be responsible for all required testing and warranty inspections not specifically noted in this proposal as DYK's responsibility. F. STANDBY TIME In the event that TDPUD has not completed the services it is to provide under this agreement by the date that DYK is required to start work, resulting in a stand bye time for DYK's personnel, or if DYK is delayed in performing its work,DYK reserves the right to seek compensation from the TDPUD for any delays caused by the TDPUD or the TDPUD's subcontractor, suppliers, agents or employees. Proposal# 100402R Page 13 8a:• G. DISPUTES In the event that a dispute has to be settled by the Courts or through Arbitration, the losing party shall pay all attorney, court and arbitration expenses incurred by the prevailing party within 10 calendar days from each date of settlement, or within 10 calendar days from date of each invoice. Payments shall not be withheld should the verdict be appealed. H. COMPLETE AGREEMENT: This document contains all covenant, stipulations, and provisions agreed by the parties. No agent or representative of either party has authority to make, and the parties shall not be bound by or be liable for, any statement,representation,promise or agreement not set forth herein. J. ACCEPTANCE: Since it is imperative to DYK that it is able to place its material orders (such as for prestressing material) before price escalations occur, this proposal is hereby offered for acceptance for a period of up to thirty(30) days. DYK reserves the right, after this period, to amend its bid and to reflect any changing construction schedules and material and labor rate changes. The return to DYK of an accepted, endorsed copy of this proposal, within the above referenced time period, will constitute a contract between DYK and TDPUD. DYK reserves the right to void this proposal and any contract with the TDPUD if the TDPUD or any related party fails to make any payments as required by law on another contract with DYK. This proposal shall be made a part of any subcontract agreement or purchase order. DYK reserves the right to negotiate or reject any or all terms of any subcontract agreement or purchase order utilized by the TDPUD. DYK will only agree to a Type III indemnity clause. DYK Incorporated Lt - I C:��-� David Gourley Vice President Construction Date: April 19, 2010 Accepted this proposal Signature of authorized person Date: Title Proposal# 100402R Page 4 N w DONNE" Attachment 2 Public Resolution No. 2010 - XX FINDING AN EMERGENCY SITUATION AT THE AIRPORT WATER TANK AND DIRECTING THAT COMPETITIVE BIDDING BE DISPENSED WITH IN CONNECTION WITH ACTION TO REPAIR AND REFURBISH THE WATER TANK WHEREAS, the Airport Water Tank was built in 1979 by Crom and is a 600,000 gallon unit constructed of prestressed concrete; and WHEREAS, the dome ring which supports the tank roof is failing and needs immediate repair; and WHEREAS, the Airport Well is the system's largest producing well and is dependent upon the Airport Water Tank to produce; and WHEREAS, the high water demand season is upon us and the District cannot afford to lose this source; and WHEREAS, a bidding process would delay the repair work for 3 to 4 weeks; and WHEREAS, DYK Incorporated is one of the few companies in the United States that specializes in construction and repair of prestressed concrete tanks; and WHEREAS, staff has negotiated with DYK to perform the repair work on the tank which could begin by the middle of May and be completed by the end of June 2010; and WHEREAS, the District's repair of the dome ring on the prestressed concrete Airport Water Tank has created an emergency which, pursuant to Public Contract Code 22050, is justification for the District to dispense with competitive bidding; NOW THEREFORE BE IT RESOLVED that the Board of Directors of the District adopt the above recitals as its findings; and BE IT FURTHER RESOLVED by the Board of Directors that for the reasons set forth above, the District finds that the failure of the dome ring on the Airport Water Tank has created an emergency and that the emergency will not permit a delay resulting from a competitive solicitation for bids and that a contract to refurbish the water tank is necessary to respond to the emergency. BE IT FURTHER RESOLVED that the District shall therefore dispense with competitive bidding for the repair of the prestressed concrete Airport Water Tank. 1 Resolution 2010-XX BE IT FURTHER RESOLVED BY THE Board of Directors that it hereby delegates the authority to take all necessary action to repair and refurbish the Airport Water Tank to the District's General Manager. BE IT FURTHER RESOLVED that the Board of Directors shall review the emergency action at its next regularly scheduled meeting and at every regularly scheduled meeting thereafter until the action is terminated to determine whether there is a need to continue the action. PASSED AND ADOPTED by the Board of Directors at a meeting duly called and held within the District on the fifth day of May 2010 by the following roll call vote: AYES: NOES: ABSTAIN: ABSENT: TRUCKEE DONNER PUBLIC UTILITY DISTRICT Jeff Bender, President ATTEST: Michael D. Holley, District Clerk 2 Resolution 2010-XX