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1b. Plans & Specs for Cleaning, Repair & Painting the 100,000 Gal Water Storage Tank and Auth Adv for Bids f j b C TY F csANBAssEN `` 690 COULTER DRIVE • P O. BOX 147 • CHANHAUBh4;! I MESOi 55317 (612) 937-1900 --* - �rdorsed�'1 Modified , MEMORANDUM l2ejscte TO: Don Ashworth, City Manager Witt Submitted to Ccmflssion FROM: Gary Warren, City Engineer Batt Submitted to Council DATE: March 22 , 1989 SUBJ: Accept Plans and Specifications for Cleaning, Repairing and Painting the 100 ,000 Gallon Elevated Water Storage Tank and Authorize Advertising for Bids File No. PW158 As Council is aware, the painting and rehabilitation of the down- town elevated water storage tank has been scheduled for this year. An interior and exterior inspection report was prepared on the elevated tank in July, 1988 and basically proposed approxi- mately $70 , 000 of necessary rehabilitation and painting for this tank. Attached is a summary of the rehabilitation elements which are covered by the specifications for rehabilitation. The specifica- tions themselves are available in my office for review but I thought the attached summary would be more convenient and understandable for review. As reviewed with the City Council on February 13 , 1989 , the tower will be painted "cumulus" consistent with the new reservoir and the Chanhassen name (not maple leaf ) will be painted on the north and south face of the spheroid. Rehabilitation of this tank is included in the water expansion budget for 1989 . It is therefore recommended that the plans and specifications for cleaning, repairing and painting the 100 ,000 gallon single-pedestal spheroid on West 76th Street be approved and authorization given to advertise for bids . Attachments 1 . Investigation Study excerpt. 2 . January 4 , 1989 staff report. cc: Jack Kollmer, AEC r INTERI DIR AND EXTERIOR INSPECTION REPORT 100 MG SINGLE PEL7ESTAL SPHEROID - EAST TOWER CITY OF CAANHA,•SSEN , MINNESOTA AEC PROJECT NO_ 6008-63 r BY AEC - ENGINEERS & DESIGNERS 511 11TH AVENUE SOUTH MINNEAPOLIS, MINNESOTA 55415 TELEPHONE 612/332-8905 am gm AM AEC • AEC - ENGINEERS & DESIGNERS 511 Eleventh Avenue South Minneapolis, Minnesota 55415 612/332-8905 ELEVATED WATER TANK INSPECTION - NO. 5008-634 Client: City of Chanhassen Tank Location: W. 76th Street & Iroquois Ave. Tank Description : 100 MG Single Pedestal Spheroid Type of Coating: Interior: Epoxy Exterior: Alkyd Inspected by: Jack Kollmer Date Of Inspection: July 25 , 1988 INSPECTION RESULTS 1 .0 Conclusions and Recommendations The following repairs or modifications are recommended: 1 . 1 Interior Structural 1 . 1 . 1 Install one ( 1 ) 24-inch round AWWA hinged ventilation roof manway approximately 180 degrees from the existing manway. This will provide proper ventilation for the removal of dust and explosive vapors during interior surface preparation and coating . For a typical manway, see AEC Standard Drawing in Appendix B. See photos in Appendix A. 1 . 1 . 2 Weld the unwelded interior seam of the existing roof manway, and one ( 1 ) small repair plate on the interior of the tank. See .photo 2 . 1 . 1 . 3 Remove all rigging brackets and scab marks below the High Water Level (HWL) by air arc gouging , cutting torch , or grinding, there are 6 rigging brackets and approximately 30 scab marks. See photos 3 , 4 & 5 and refer to Appendix C Surface Preparation Requirements. Remove by grinding all random and excessive weld splatter on weld seams. 1 . 1 . 4 Epoxy caulk gaps or porosity of the overlapped roof plates and roof plate to shell plates. See photos 6 & 7 . 1 . 1 . 5 Weld the unwelded underside of the single stiffener on the dry well tube. See photo 8. 1 . 1 . 6 Add "T" handle wrench to drain plug to facilitate drain plug removal for tower cleaning and maintenance . See photo #9 . Branch Ottice: 13807 Village Mill Drive • Midlothian, Virginia 23113 • 8041379-3944 . w Page 2 Project No. 5008-634 1 . 2 Interior Coating 1 . 2. 1 Visually, the interior coating is in almost perfect condition with very few rust spots or coating failures. However, the coating on the lower shell and bowl area has started to fail in the form of blisters of 1 /4 to 1 inch in diameter. See photos 10 and 11 . 1 . 2. 2 The coating should be replaced in 3 to 5 years. 1 . 2 . 3 After structural repairs are completed, the entire reservoir surfaces should be properly prepared and the coating replaced with light-colored polymide epoxy system, similar to Rust-Oleum Series 9500 Epoxy , Koppers Hi-Guard Epoxy , or the Tnemec Series 20 Pota-Pox Epoxy . 1 . 3 Exterior Structural 1 . 3 . 1 The owner should consider to replace the tank vent/assembly with a new mushroom style, removable top , vent similar to AEC Standard Drawing as found in Appendix B. See photo(s ) 12 & 13 for reference to current conditions . The new vent and vent screen design should meet Awwa D100 and local Health Department regulations. The removable top will also allow for access to the tank interior for ventilation and rigging during reconditioning. The present vent assembly does not meet totally the Health Department regulations for roofs or vents . Install a welded or bolted in place cover over the present ventilation opening . 1 . 3 . 2 Install a hasp and locking device on the roof manway . Health Department regulations require • "manholes above the waterline shall have a locking device" . See photo 14. 1 . 3 . 3 Install an overflow pipe screen retainer assembly and screen to meet Health Department regulations . Use a corrosion resistant, heavy-gauge screen with a mesh size no smaller than 1 /4 inch square opening . See photo 15 , and AEC drawing in Appendix B. AEC Page 3 Project 5008-634 1 . 3 .4 Epoxy caulk porosity around anchor bolts and base plates to halt corrosion from standing rainwater . See photo #16 . 1 .4 Exterior Coating 1 .4. 1 Due to age, chalking , deterioration, some lack of intercoat adhesion, and lack of resistance to mechanical damage ( rocks) and graffiti , the entire exterior coating should be removed and replaced with an epoxy/urethane coating system, similar to those manufactured by the Koppers or Tnemec companies. The exterior reconditioning should be scheduled at the same time as the interior. This will allow the interior and exterior reconditioning schedules to coincide , is more cost effective, and prevents additional tower out-of-service time. See photos 17 thru 20 for interior and exterior dry area paint conditions. 2 . 0 Engineering Cost Estimates 2. 1 Interior structural repairs $ 4 , 600 2 . 2 Interior coating Type of coating - epoxy system $ 16 , 750 2 . 3 Exterior structural repairs $ 1 , 925 2 .4 Exterior coating Type of coating - epoxy/urethane system $ 35 , 275 2 . 5 Engineering specifications and inspection fee $ 11 , 550 2 . 6 Estimated Total Cost $ 70 , 100 2 . 7 Estimated job duration 4 weeks 2 . 8 These cost estimates represent the current pricing structure. If you plan to proceed with the coating of this tank , the sooner the specifications are ready for bidding , the more competitive the bids will be. AEC . Page 4 Project No. 5008-634 3.0 Future Inspection Schedule 3. 1 The tank painting should be first inspected within the warranty period, and every three years thereafter. 4.0 Life of Coating System 4. 1 With the recommended paint system and a regularly scheduled tank inspection and maintenance program, the tank interior and exterior should not require complete recoating for the next fifteen to twenty years. Report submitted by: AEC - ENGINEERS & DESIGNERS d‘ig! ohn R. Buzek, P. E. President / // /9/( Date + _Idsur-es - Field Inspection Report - Appendix A - Appendix B - Appendix C 1;..c.han634 AEC FUND: 402 WATER EXPANSION FUNCTION: CAPITAL PROJECT FUND 1989 BUDGET t 6a mPn+-...., This fund derives its money from water hook-up charges and is dedicated to oversis general benefit costs associated with the water utility � and other pay system. Revenue into this fund fluctuates based on development greatly in that collections are o in areas where trunk costs were assessed as part of the construction project. oject. FIVE YEAR CAPITAL IMPROVEMENT PROGRAM FOR THE CHANHASSEN WATER SYSTEM YELL: LESCRIETIL r ESTIMATED 1983 Install chart recorders on wells and elevated tanks 15,000 Watermain replacements 1. Bowling alley 12,000 2. Creek Run 8,000 20,000 General repairs 1989 45,000 Painting and general repair of West 76th Street water tower 75,000 Remove pumps and liner at well #4 and overhaul/repair as necessary 25,000 Construct Lake Lucy Road Trunk Watermain 150,C00* General Repairs 1990 260,000 Construct Well #5 80,000 Painting and general repair of Murray Hill Water tower 120,000 General Repairs 15 ��C 1991 215,000 Remove pumps and liner at well #2 and overhaul/repair as necessary 30,000 General Repairs 15.Q00 1992 General Re Pairs 45,000 15.000 Note: 15,000 Lake Lucy trunk watermain feasibility has study will pose several funding y been authorised. The feasibility$200,000 Bonds of 1986, $150,000 - 402. y scenarios. -78- CITY OF NEA, SSEN 690 COULTER DRIVE • P.O. BOX 147 • CHANHASSEN, MINNESOTA 55317 (612) 937-1900 " :,i.u7trptM MEMORANDUM `f0 ' ' •�------ W TO: Don Ashworth , �..\ ��`� City Manager FROM: Gary Warren, City Engineer v- 6,.t4.,.. Subtnrttea to L 11Ctt DATE: January 4 , 1989 SUBJ: Authorize Preparation of Plans and Specifications for Cleaning, Painting and Repairing 100 ,000 Gallon Elevated Water Storage Tank on West 76th Street File No. PW158A When the City placed its new 3.5 million gallon reservoir on-line last April, altitude valve improvements and modifications were done to the 100 ,000 gallon elevated water storage tank located in - the downtown area. The downtown tank was built in 1965 and ori- ginally painted in 1966 . The tank exterior and interior was repainted in 1978 . The firm of AEC Engineers , specialists in this type of work, inspected the tank and have prepared a report summarizing the repairs and modifications which are recom- mended at this time for this tank. The attached sheets are excerpts from this report and, as summarized on page 3 , the engi- neer ' s cost estimate for these repairs is approximately $70 ,100 . While the 100 ,000 gallon capacity of this tank is relatively minor compared to the new reservoir, this tank does provide for necessary backup in the system if and when the new reservoir is taken down for maintenance purposes. The City' s 1989 Water Expansion Fund ( 402 ) includes a $75,000 budget item for these repairs. The color format chosen for the new reservoir will be used for this tank as well . The next step in accomplishing this task is to prepare plans and specifications for bidding the project. Staff is very satisfied with the services provided by AEC Engineers and it is therefore recommended that they be authorized to prepare the plans and spe- cifications for rehabilitation of the 100 ,000 gallon elevated water storage tank in accordance with the recommendations pre- sented in the evaluation report dated August 11 , 1988 . Attachments 1 . Evaluation Report Excerpts. 2 . Fund 402 CIP Budget Sheets. 3 . AEC Contract.