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Mr. John Gerhardson <br />City of Orono <br />Page 2 <br />December 5. <br />2, Rtfvise «;T;^rr^no ec]uipment: The motor starting e^uiprnent (which has not been <br />built) can be changed to a type that starts the pump slowly and gradually brings it up <br />to full speed. This allows the water velocity through the sandrock to increase at <br />gradual rate, minimising surging that may isc causing increased sand content on <br />stamp. This type of starting equipment is more costly than the type which brings the <br />pump to full speed in a matter of seconds. <br />The present motor control system is sized to operate a 1000 gpm pump in the future. <br />The size of the motor control equipment may remain the same or may be reduced <br />to only operar.- a 500 gpm pump. The additional cost to the project for various <br />control 0^are; <br />a.Proude the same size motor starter Add $5,yy2.0(i <br />b.Mabtain the same size electrical <br />scrs'icc and provide a motor <br />starter for a 500 gpm pump.Add S."!,360.no <br />c.Reduce the electrical se.^ice and <br />motor starter for a 500 gpm pump.Add $2,310.00 <br />The best option depends on if and when it may be desired to increase the well capacity, <br />remembering that control options are small in cost compared to well development costs. <br />Based on present worth, option ^a) would be selected if well capacity would be increased <br />within the next C-1 years. If the incrcMse is after 7 years, option (b) is cost effective. Option <br />(c) would be seleaed if there i"- uo desire to increase capacity or the increase would be in <br />20 years. As additional work on the well is not cos: effective at this time, we recommend <br />that the well be accepted. <br />We recommend that the starting equipment be revised to minimize pumping sand rather <br />than redeveloping the well at this time. We also recommend reducing the starter size <br />(option b) unless the city predicts a larger capacity w^il be required in the next 6-7 years in <br />this area. <br />The delay b the pumping facility construction, u additional well development, has <br />increased the contractor ’s cost due to winter conditions. Start of construction was <br />anticipated on August 1, 1990 and actual construction could not start until November 14, <br />1990. It is necessary to enclose and heat the masonry work to prevent freezing, and to <br />protect the exterior surfaces of hydropneumatic tank and building over winter months. The <br />contractor has requested the following to cover extra expenses: