Laserfiche WebLink
Therefore, the revised formula is as follows: <br />A+ C+ D+ E <br />B x F <br />Where A = Permeability index <br />B = Water body index <br />C = Average age of system index <br />D = Water table index <br />E = Potable water supply index <br />F = Density index <br />The indexes are calculated and assigned a weight factor and then added together. Since density <br />and water body index are the most important issue of onsite systems, it is given a reverse index and <br />is placed in the denominator. Thus, the range will be between 1.00 and 160.00. The lower the <br />score, the better suited the area would be for septic use, and the higher the score the better suited <br />for centralized sewer. <br />The indexes are as follows: <br />PERMEABILITY INDEX (A) <br />Average Permeability <br />Index <br />Examples of Soils <br />> 20" per hour <br />5 <br />Astatula fine sand, Canaveral sand <br />6.0" — 2.0" <br />4 <br />Apopka fine sand, Myakka fine sand <br />2.0" — 6.0" <br />3 <br />Chobee fine sandy loam <br />0.6" — 2.0" <br />2 <br />Myakka Variant fine sand, Gator muck <br />0.2" — 0.6" <br />1 <br />Bluff sandy clay loam <br />Note that the index is high for excessively drained and poorly drained soils. The actual permeability <br />for a particular site depends as much upon the site as it does the soil type. <br />WATER BODY INDEX (B) <br />Proximity to Surface Water <br />Index <br />Adjacent to Indian River Lagoon <br />0.25 <br />Adjacent to MRC, NRC, SRC or St. Sebastian River <br />0.5 <br />Adjacent to a sub -lateral or IRL <br />1 <br />Adjacent to a roadside swale <br />2 <br />Not adjacent to a waterbody <br />3 <br />This index is low for parcels of land where a water body is adjacent and high for areas far from a <br />water body. Ideally you would not want a septic system near a body of water where food is <br />harvested such as clams and oysters or in this case adjacent to a major canal or Indian River Lagoon. <br />AVERAGE AGE OF SYSTEM (C) <br />Average of System <br />Index <br />> 26 years <br />5 <br />17 to 26 years <br />3 <br />11 to 16 years <br />2 <br />1 to 10 years <br />1 <br />F-\Utilities\UTILITY - Engineering\Projects - Utility Construction Permits\IRC - Sewer Feasibility Studies UCP # 4101\Agenda Items\Agenda-Septic to <br />Sewer.doc 80 <br />