Orange County NC Website
Browse       Search
9 • ' . . 12 <br /> 4 <br /> 10 t- <br /> Pressurized Alternative Wastewater <br /> ♦ c • <br /> 4 <br /> (Septic Tank Effluent Pumping) <br /> • <br /> 4 <br /> ♦ FULFILLING A NEED CONCEPT DEFINITION <br /> Although many sanitary consulting • <br /> 1.1 One of the most difficult problems engineers have had some ex- <br /> , for today's individual home builder perience with pressure sewers, there <br /> 4 and residential developers is finding are others who have had little exposure <br /> available land for building homes to the concept. Therefore, as a start, <br /> 4 that will readily lend itself to sewage let's define a pressure sewer system. <br /> disposal either by on-site systems _ <br /> or gravity sewers. The price of good A pressure sewer is sometimes <br /> 4 land for development has become described as a potable water system <br /> so expensive in many areas that it in reverse. By this, we mean a water <br /> 4 has forced the individual builder and system will have one inlet pressuri- <br /> zation point and a number of end <br /> on what is referred to as undesirable user connections, while a pressure ' <br /> 4 land. These areas can be normally sewer will normally have a pressuriz- <br /> described as rocky, contain major ed inlet point at each end user con- <br /> 4 elevation differences and may have nection and one discharge outlet at <br /> high water tables. In addition, soil a treatment plant or discharge point. <br /> 4 structures in many areas of the The number of end user connections <br /> United States do not lend themselves could be anywhere from a few to <br /> to on-site treatment systems. several thousand. <br /> 4 <br /> It is universally recognized that there A pressure sewer system is made up <br /> 4 is a major need for a more econom- <br /> ical method of collecting, transport- A. Pump package system (basin, <br /> ing and treating sewage other than pump piping, controls, control . <br /> gravity sewers.This would be espec- panel, alarm) <br /> pally true in areas containing rock, B. Service lines and force mains <br /> 4 rough terrain, sparsely settled and C. Discharge treatment point <br /> high water table areas. There are two <br /> primary types of • <br /> pumps used in pressure sewers. <br /> One of the most viable alternatives One is referred to as a grinder pump <br /> 4 to gravity sewers that has gained a (GP) and the other an effluent pump <br /> great deal of attention over the past (STEP) which is located in or behind <br /> 4 several years is the concept of pres- a septic tank The major difference <br /> sure sewer systems.There have been between the two pump types is how <br /> over 150 of these systems (100-1500 the solids are handled. <br /> 4 connections) installed since 1970 <br /> with a large number currently under In the case of GP units, the solids <br /> 4 evaluation, design, or installation. are ground into a slurry and pumped <br /> to a discharge point. <br /> Pressure sewers under the US-EPA t With a STEP <br /> grants program are defined as alter- pump, the settleable solids and <br /> 4- native systems, but not innovative - most of the grease accumulation <br /> since their performance and reli-. remain in the septic tank. Conse- <br /> 4_ ability has been proven in over 14 quently, the STEP pump conveys a- <br /> years of operation. fairly clear effluent to the discharge <br /> point. . - <br /> ■ _ _ _ 1 <br /> �• CRAIG B.AAORGAN AND ASSOCIATES.P.A.- 1 <br /> 4 <br />