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8 <br /> 1 Slide #10 <br /> Standards for Effluent Quality <br /> Septic Tank <br /> Effluent I<------------ Advanced Pre-Treatment ---------->1 <br /> ANSI J ' <br /> BOD-5: 350 mg/I CBOD: 15 CBOD: ill <br /> TSS: 100 mg/I TSS: 15 TSS: 10 <br /> TKN: 100 mg/I NH3: 10 NH3: 10 <br /> 7 to 15 x better than DSE <br /> 2 <br /> 3 Tony Whitaker said success in wastewater treatment is measured by how well <br /> 4 concentrations of certain undesirable characteristics or constituents can be removed, which are <br /> 5 represented on this slide. He said the left represents the least treated effluent standard, and <br /> 6 they are increasingly well treated moving to the right. The concentrations listed are the <br /> 7 maximum allowable concentrations that are generally allowed to flow out of a septic tank and <br /> 8 then be directly dispersed to good, suitable soil for further treatment. However, he said most <br /> 9 water coming out of a septic system is better. <br /> 10 Chair Bedford asked what BOD means. <br /> 11 Tony Whitaker said, Biological Oxygen Demand, is a measure of the load of certain <br /> 12 kinds of bacteria and biological components that consume oxygen as they break down, so that <br /> 13 when the load is sent downstream to oxygenated water, the change to the oxygenation levels in <br /> 14 that water can be observed. <br /> 15 Commissioner Bedford asked him to elaborate on TSS and TKN. <br /> 16 Tony Whitaker said TSS refers to Total Suspended Solids, and TKN is a combination of <br /> 17 different types of nitrogen. He noted that these standards are for the water that's applied to the <br /> 18 soil. He said if the soil is very limited, it could do some treatment, but not great treatment; <br /> 19 advanced pretreatment may be needed, which takes that water to a higher level of treatment <br /> 20 before it is dispersed. He said the water is 7 to 15 times better with advanced pretreatment than <br /> 21 the DSE standard, but it comes at a high cost. <br /> 22 <br /> 23 <br /> 24 <br /> 25 <br /> 26 <br /> 27 <br /> 28 <br /> 29 <br /> 30 <br /> 31 <br />