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Bob Keating <br />prom: Mike Hotchkiss <br />nt: Friday, June 28, 2013 5:07 PM <br />o: Stan Boling; Bob Keating <br />Cc: Vincent Burke <br />Subject: RE: Issues Related with Expanding Water and/or Sewer Service Outside the USA <br />Issues related to expanding water and sewer outside the USA: <br />1. The current system has been designed with transmission mains, pump <br />stations, storage tanks, treatment facilities, etc. to only serve a finite region <br />with a relatively standard density. To suddenly make the decision to expand <br />beyond that finite region to an infinite area that is generally lower density is <br />very difficult. It is also difficult to design the lower density areas, because you <br />need large transmission mains and larger pumps to provide fire flow, but the <br />normal demands associated with a lower density means that the large pumps <br />rarely flow at their optimum efficiency. <br />2. To design transmission mains, treatment facilities, storage facilities, etc. to be <br />adequate to provide fire flow to a remote region with a relatively low density is <br />very expensive per capita compared with serving a region designated for a <br />higher density. This results in higher impact fees and higher maintenance <br />and depreciation costs than would normally be seen in a higher density <br />region. <br />3. There are also issues related with water quality on serving lower density <br />areas that have the same fire flow demand, but have a lower average daily <br />demand. This is due to lower velocities flowing thru water mains designed for <br />large fire flows. The chlorine residual deteriorates due to longer detention <br />times in the main and results in poor quality water. The customers then <br />complain resulting in the need to flush water mains, that waste water that <br />would normally be sold. This results in increased operation and maintenance <br />cost per capital resulting in higher rates for customers because all customers <br />must subsidize the treatment and maintenance cost of the lower density <br />areas. <br />4. The larger transmission mains, treatment facilities, storage facilities and <br />pumps also result in higher depreciation due to the higher value of the <br />infrastructure. <br />5. Unidirectional extensions of the utility lines outside the USA without the <br />possibility of looping the distribution creates potential dead-end lines that <br />could contribute to water quality concerns and reliability issues. <br />W <br />Michael C. Hotchkiss, P.E. (FL) <br />apital Projects Manager <br />%Pndian River County Utilities <br />1801 27th Street <br />172 <br />