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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 /> Vidian River County Utilities <br /> 1801 27th Street <br /> 1 172 <br />