Orange County NC Website
,~~,-~ a. <br />MEMORAi`1DUM <br />TO: County Commissioners <br />Toter; Link, County Manager <br />FROM: Paul Thames, PE, County Engineer <br />DATE: March 9, 2000 <br />SUBJECT: Preliminary summary of the evaluation of relationship between water use and home size <br />in the Efland area <br />The BOCC, at the 19 October 1999 meeting and public hearing on revisions to the "Rules and <br />Regulations for Operation of the System" for the Efland sewer system, adopted a revised fee structure <br />for access. and taps onto the system. The Board did, however, direct staff to conduct a study of water <br />use in the Efland area to determine if there was a demonstrable correlation between water use and size <br />of dwellings. The underlying concept was to ascertain (in a manner similar to a recent OWASA water <br />and sewer availability fee study) if a sliding scale of availability fees determined by home size could be <br />j Usti-feed on the basis of varying degrees of service demand impact on the system. <br />Accordingly, County Engineering .Associate Abdoul Koura-Bodji has spent approximately 300 hours in <br />the process of collecting, evaluating, manipulating and analyzing water use and property tax record data <br />on current Orange-Alamance Water System.customers. The data collection effort has been targeted at <br />those customers living in the area that would become a part of a built-out Efland sewer system if that <br />system were developed in accordance with~the 1986 sewer master plan. <br />The study area, includes approximately 532 metered customers of Orange-Alamance (the area also <br />contains an unknown number of homes served by on-site wells). However, the analysis of water use <br />relative tQ home size eventually came to include only 458 customers. Forty-two customers were <br />eliminated asnon-residential users. An additional thirty-two customers were eliminated because the <br />water use records were problematic (building may have been unoccupied, for example) or because the . <br />customer records could not be matched with the County's property and property tax data (size of <br />~~building could not be determined). Of the 458 customers included in this analysis, 348- were in "stick- <br />built" houses and~fixed foundation double-wide mobile homes (bath types of dwelluag having property <br />tax data that includes heated squaze footage). The remaining 110 customers were in single-wide mobile <br />homes thaf were assumed to have a maximum size of 700 square feet. The average home size, <br />excluding the single wide trailers, was found to be 1320 square feet with an average monthly watez use <br />of 4370 gallons. The average water use for the single-wide trailers -with the assumed average size of <br />700 square feet -was found to be 4150 gallons per month. <br />Analysis of the data collected for the customer base described above does show a relatively consistent <br />and direct correlation between the size of a home and the amount of water used if the water use of the <br />sin~te-wide mobile homes is not included iu the analysis: The water demand for the single wide <br />mobile homes, when compared to the square footage of the units, is such that it skews the analysis. <br />When home sizes are separated into five ranges -less than 900 square feet, 901 to 1200 square feet, <br />s <br />