Orange County NC Website
<br />MEMORANDUM <br />TO: County Commissioners <br />John Link, County Manager <br />FROM: Paul Thames, PE, County Enginee <br />DATE: Maxch 20, 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 Eland 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 />justified 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 198b sewer master plan. <br />The study area includes approximately 532 metered customers of Orange-Alamance (the area also <br />contains an unlmown number of homes served by on-site wells). However, the analysis of water use <br />relative to home size eventually came to include only 458 customers. Forty-two customers were <br />eliminated as non-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 4S8 customers included in this .analysis, 348 were in "stick- <br />built" houses and fixed foundation double-wide mobile homes (both types of dwelling having property <br />tax data that includes heated square footage). The remaining 110 customers were in single-wide mobile <br />homes that 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 water 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 le-wide mobile homes is not included in the anal sis. 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 aze separated into five ranges -less than 900 squaze feet, 901 to 1200 squaze feet, <br />