Orange County NC Website
10WASAI ORANGE WATERAND SEWERAUTHORHY <br />Quality Service Since 1977 <br />�i I' U (I) =M <br />TO: Gordon Sutherland <br />FROM: Ed Holland <br />DATE: June 22, 2007 <br />SUBJECT: Preliminary Concept Plans and Cost Fstimates for Providing Sewer <br />Service to the Rogers Road Study Area <br />Background and Overview <br />Per our recent meetings, OWASA staff has provided three concept plans and associated <br />cost estimates (preliminary) for a sewer collection system that could serve the Town of <br />Chapel Hill's study area east of Rogers Road. Virtually all existing parcels in the study <br />area have access to OWASA water lines; therefore, this exercise focused on sewer <br />service only. If the Town or others decide to pursue these or other sewer concepts, <br />additional engineering and professional services will be needed to provide site -level <br />detail and an overall determination of project feasibility. <br />The concept plans represent three potential gravity flow configurations. None <br />incorporate sewage pumping stations, which OWASA only approves in unusual <br />circumstances where property cannot be served by gravity options. We have found that <br />pumping stations are expensive to maintain and less reliable over time, due to the greater <br />risk of mechanical failure and resulting sewage spills, than are gravity systems. As <br />shown in Concepts A and B, wastewater from most of the study area would flow toward <br />the upstream portion of a sewer line that the Town of Carrboro is extending <br />approximately 900 feet to an area that was annexed in 2006. According to North <br />Carolina annexation laws, that facility must be completed by the end of January 2008. <br />Our concept drawings do not include portions of the sewer system that will be installed <br />for properties within the study area that are being developed by Habitat for Humanity, <br />nor do these concept plans anticipate service to most of the Greene Tract, which are <br />intended to remain as permanent open space. <br />Under Concepts A and B, sewer service would not be available to 11 existing parcels in <br />the study area, as indicated by purple cross - hatching on the drawings. Additional sewer <br />lines near the southeastern portion of the study area would be.needed to serve 10 of those <br />11 lots, as shown in Concept C. None of the three concepts plans could provide sewer <br />service to the single small lot in the extreme northwest corner of the study area <br />