New Search
5.2.1 Calculating The Number Of ESUs Belonging To A Customer <br /> ESUs are calculated differently for general storm customers than for small and medium <br /> residential customers. To calculate the number of ESUs belonging to a general storm <br /> customer, divide the amount of the customer's impervious surface area by 1,000, the <br /> resultant being the number of ESUs. If the result is a number with a decimal or fractional <br /> element, truncate to the whole number. For example, if a restaurant has 15,670 square <br /> feet of impervious surface, then the restaurant has 15,670/1,000 = 15.67 = 15 ESUs. <br /> Thus, every additional 1,000 square feet of impervious surface represents an additional <br /> ESU. A customer with 1,000 to 1,999 square feet of impervious surface has 1 ESU; a <br /> customer with 2,000 to 2,999 square feet of impervious surface has <br /> 2 ESUs, etc. The minimum number of ESUs a customer can have is 1. So, customers <br /> with 1 to 999 square feet of impervious surface are automatically assigned an ESU of 1. <br /> See Figure 4. <br /> The number of ESUs for the two residential categories is calculated differently than <br /> ESUs for general storm customers. Most residential customers fall into the small or <br /> medium residential category depending on the size of their estimated building foot print. <br /> . If the customer's building foot print plus garage area is 1,000 square feet or less, the <br /> customer falls into the small residential category. If the customer's building foot print <br /> plus garage area is between 1,000 and 3,000 square feet, the customer falls into the <br /> medium residential category. See Figures 1-3. <br /> While building foot print determines which category a residential customer belongs in, <br /> the amount of the fee will be based on the amount of total impervious surface on a <br /> typical property within a category. Driveways, sheds and cement porches are examples <br /> of impervious surfaces that are not included in the building foot print measurement but <br /> do figure into the calculation of the total impervious surface for that category. Based on <br /> sample data, the ESU measurement for a small residential account is set at 1.8. Medium <br /> residential accounts are set at 2.9 ESUs. <br /> The utility determines impervious area and building foot print information from <br /> Assessment and Taxation records, aerial photos, building permit data, and other sources <br /> as appropriate. . <br /> Stormwater Service Charge: Methodology Paper -Page 6 <br /> Draft Revisions -April 10, 1995 <br /> <br /> t <br /> <br />