Laserfiche WebLink
Priority Pollutant Percent Removal Efficiencies (%) Through Activated Sludge Treatment* <br />Priority Pollutant <br />Range <br />Second <br />Decile <br />Median <br />I <br />Eight <br />I Decile <br />Number of POTWs <br />with Removal Data <br />METALS/NONMETAL INORGANICS** <br />Arsenic <br />11-78 <br />31 <br />45 <br />53 <br />5 of 26 <br />Cadmium <br />25-99 <br />33 <br />67 <br />91 <br />19 of 26 <br />Chromium <br />25-97 <br />68 <br />82 <br />91 <br />25 of 26 <br />Copper <br />2-99 <br />67 <br />86 <br />95 <br />26 of 26 <br />Cyanide <br />3-99 <br />41 <br />69 <br />84 <br />25 of 26 <br />Lead <br />1-92 <br />39 <br />61 <br />76 <br />23 of 26 <br />Mercury <br />1-95 <br />50 <br />60 <br />79 <br />20 of 26 <br />Nickel <br />2-99 <br />25 <br />42 <br />62 <br />23 of 26 <br />Selenium <br />25-89 <br />33 <br />50 <br />67 <br />4 of 26 <br />Silver <br />17-95 <br />50 <br />75 <br />88 <br />24 of 26 <br />Zinc <br />23-99 <br />64 <br />79 <br />88 <br />26 of 26 <br />ORGANICS** <br />Anthracene <br />29-99 <br />44 <br />67 <br />91 <br />5 of 26 <br />Benzene <br />25-99 <br />50 <br />80 <br />96 <br />18 of 26 <br />Chloroform <br />17-99 <br />50 <br />67 <br />83 <br />24 of 26 <br />1,2-trans-Dichloroeth lene <br />17-99 <br />50 <br />67 <br />91 <br />17 of 26 <br />Eth (benzene <br />25-99 <br />67 <br />86 <br />97 <br />25 of 26 <br />Methylene chloride <br />2-99 <br />36 <br />62 <br />77 <br />26 of 26 <br />Naphthalene <br />25-98 <br />40 <br />78 <br />90 <br />16 of 26 <br />Phenanthrene <br />29-99 <br />37 <br />68 <br />86 <br />6 of 26 <br />Phenol <br />3-99 <br />75 <br />90 <br />98 <br />19 of 26 <br />Bis 2-eth (hex Iphthalate <br />17-99 <br />47 <br />72 <br />87 <br />25 of 26 <br />Butyl benzyl phthalate <br />25-99 <br />50 <br />67 <br />92 <br />16 of 26 <br />Di -n -but I phthalate <br />11-97 <br />39 <br />64 <br />87 <br />19 of 26 <br />Diethyl phthalate <br />17-98 <br />39 <br />62 <br />90 <br />15 of 26 <br />Pyrene <br />73-95 <br />76 <br />86 <br />95 <br />2 of 26 <br />Tetrachloroethylene <br />15-99 <br />50 <br />80 <br />93 <br />26 of 26 <br />Toluene <br />25-99 <br />80 <br />93 <br />98 <br />26 of 26 <br />11111 -Trichloroethane <br />18-99 <br />75 <br />85 <br />94 <br />23 of 26 <br />Trichloroethylene <br />20-99 <br />75 <br />89 <br />98 <br />25 of 26 <br />Pollutant removals between POTW influent and secondary effluent (including secondary clarification). <br />Based on a computer analysis of POTW removal efficiency data (derived from actual POTW influent and <br />effluent sampling data) provided in U.S. EPA's Fate ofPriority Pollutants in Publicly Owned Treatment <br />Works, Volume II (EPA 440/1-82/303), September 1982. <br />* * For the purpose of deriving removal efficiencies, effluent levels reported as below detection were set equal <br />to the reported detection limits. All secondary activated sludge treatment plants sampled as part of the <br />study were considered. <br />Source: U.S. EPA's Guidance Manual on the Development and Implementation ofLocal Discharger Limitations <br />Under the Pretreatment Program, December 1987, p. 3-56. <br />R-2 <br />