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Bergerson - Caswell Inc. 5115 Industrial Street • Maple Plain, MN 55359 Telephone: 763 - 479 - 3121 Fax: 763 - 479 – 2183 E-Mail: info@BergersonCaswell.com Equal Opportunity Employer/Contractor Bergerson - Caswell Inc. 5115 Industrial Street Maple Plain, MN 55359 (763) 479-3121 Fax: (763) 479-2183 November 9, 2023 CITY OF NEW BRIGHTON Attn: Mr. Jesse Hartman (651) 755‐1529 cell 803 Old Hwy 8 NW (651) 638‐2114 office New Brighton, MN 55112‐2792 (651) 638‐2044 fax RE: WELL PUMP #6 PREVENTATIVE MAINTENANCE INSPECTION REPORT 2023 Bergerson‐Caswell Inc. Appreciates the opportunity to assist you and your well pump needs. As requested we tested and removed the pumping equipment, we disassembled, cleaned, and inspected all components to provide you with a status and our recommendations to recondition and repair all components. I have taken all measurements on the pump and reviewed the information to verify that it matches what the modified pump design was from Les P. & Kerry T. from the City back in 2006, and it does. I did this to verify that this pump was not too big for the motor. Based on the design it does use 100% of the 150 Hp when pumping over 900 Gpm and running at full speed. Because this past summer you had mentioned the motor was running hotter than the other well pump motors, and you were just concerned. The motor shop did not see any signs that the motor was any having issues or running out of its operating range of variables. The grease even appeared normal in color and consistency, which is the first place that will show sign of excessive heat. The Motor passed all pre‐tear down tests and they recommended only normal maintenance such as bearings replacement and spray varnish to windings and rotor body. Reconditioning this motor is ¼ the price to replace it with new. The next item to address is that as long as I remember this well has had issues with sand pumping and I recall that another contractor may have cleaned the borehole of sand stone after it had failed or broke a shaft, but I am really asking if someone has done this and if so what was the bottom at that time. Because the well has filled in an additional 10’ since we were in it in 2015. We probed the bottom at 495’ but the video bottom showed 491’, (but there is an off set that should be around 4’ so it matches the measured depth. When the drilled depth was 518’ and we had depths in the past of 504’ to 507’, but now it is less than 500’, our pre removal test does have sand at all flow rates, and it is at or near the level of acceptable for a public water well. In addition the pump installation also shows signs of sand pumping wear. Therefore I have concerns that if we do not do something about this now we could have problems when this well is required. I haven’t heard of the pump being sand locked in recent years, like I know it had been more than others years ago, but that has been mitigated in the controls sequence as well as with the controlled bleed back valve on the tail pipe. I don’t believe it is critical to remove this sand material now based on the size of the borehole seen in the video I performed this week. If the sand being pumped doesn’t affect the WTP performance, I feel it will be fine to budget for this and perform the cleanout in the future. Now for the really good news, the pump is repairable, but there are a couple of items on my estimate that need adjustment, and I did not consider the need to replace spider bearings, but you had a Screw in type for just a little more than half, and they should also get replaced. we had 20 man hrs just getting 17 of them out of the column couplings we damaged more than half but that style is not typically used anymore. So I have added this as well as line shaft sleeves because the shafts are sand cut and will need sleeves from this point forward. I have provided an updated current project cost for our recommended repairs using the values that we previously bid. Please review this as well as the information provided along with this letter and give me a call to discuss because there is a lot of information here. PROJECT COST: 1) Furnish Labor & Equipment necessary Remove, Inspect, & Reinstall pump unit #6 $11,500.00 2) Deliver & pickup from motor shop, (Replacement with US 150 Hp model DN11 $21,370.00) Recondition your Yasikawa 150 Hp Bearings, spray varnish winding & rotor body, balance, test $ 4,500.00 3) Performance testing on pump installation & provide results to city $ 750.00 4) Measure the well depth (521’original & 505’ in 2015, current 495’) $ 100.00 5) Perform video inspection provide DVD, flash drive, and hard copy report to city $ 2,500.00 6) Disinfect well casing with 200 ppm solution of chlorine as performed per city $ 2,000.00 7) Disassemble the pump bowl assembly $ 650.00