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<br />Water Treatment PIClnt Production Study <br />---_._------_..._---_.._~._-,----------_.._------~.-.~--.-------"---..------ -- ---- ---------------...---------- -. <br />~'::;._:':_.:::_:;~~.':.~~:~~~':.=:'.~~~:;:~_!_~~...:..=~~...:'~. "':.-~~.:<bl~ l::': ~::'::~~_'......~~:R:~~~'~_..:..:..~~~"~~c::': 1:.:~~~ .==:-1:-~.:; !-'~~':>'~~~.~~~~:_i:'_':::::~"':'-~._:___~~.ti~~.:..(~.~ ,"'-'~"'llO<"._~~~~;;;;, .. <br /> <br />--- <br />--,,,....,.~_. ". . "~ .~.... ~:'-. <br /> <br />SAFE DRINKING WATER ACT COMPLIANCE <br />CIlY OF LONGVIEW <br /> <br />Freese and Nichols, Inc. was authorized by the City of Longview to conduct <br />treabnent plant evaluations for the Sabine Water Treabnent Plant (16 MGD) and the <br />Cherokee Water Treabnent Plant (27 MGD) in order to meet the newly promulgated <br />Stage 1 Disinfection Byproduct Rule (Stage 1 DBPR) and Interim Enhanced Surface <br />Water Treabnent Rule (IESwrR); especially the TOC removal requirement of the <br />DBPR. The Stage 1 DBPR and IESwrR were promulgated on December 16, 1998 <br />and the compliance date for the City of Longview for both regulations is January 01, <br />2002. The IESwrR sets more stringent turbidity limits in the finished water to reduce <br />the risk of Cryptosporidium outbreaks in the distribution system. Also, continuous <br />turbidity monitoring for each filter is required by the IESWfR. The Stage 1 DBPR <br />lowers the existing total trihalomethanes (TIHM) limit and set a new limit for <br />haloacetic acids (HAAs). In addition, depending on raw water quality, a certain <br />percent of total organic carbon (TOC) removal is required by this rule. <br /> <br />A principal area investigated with respect to TOC removal was the basic chemica <br />treabnent process, coagulation using alum, Polymer Blend "A" and Polymer Blend <br />"B". The two polymer chemicals are made by a single manufacturer. Promulgated <br />Stage 1 DBPR would require the City of Longview to operate both water plants in <br />"Enhanced Coagulation" mode, increasing the cost of operation and possibly <br />making turbidity removal more difficult. The purpose of enhanced coagulation is to <br />achieve higher percentages of TOC removal and reduce disinfection byproducts such <br />as TIHMs and HAAs. <br /> <br />r <br />-:.0 <br /> <br /> <br /> <br /> <br />pH <br /> <br />E""HANCED COAGULATIO:>l T1!STS BY HYPER IO~ 7502A <br />Clly or Lonl\'lewt Cherokee WTP. <br />Sec~_Q_~~~~...__ <br /> <br />RAW W A T'ER TOC . 5.25 mgIL <br />RAWWATERALKALLNrrY '" 17mgll. '" <br />C.coo <br /> <br />--."'STEPI1'tlCR1!.\tO\'A~I;;-4j~- - <br />STEP 2 TOe RIntOV.o\L::z: 4 1.9% <br /> <br />.. I --.- <br /> <br /> <br />STEP2/ <br />__.JQC.IlJ~MO)O:^!-,{41 <br /> <br />~"3 <br />E <br />:J <br />P <br />i ]U <br />~ <br />'!I <br />~u <br /> <br />The second area of the study was a preozonation evaluation, to assess the potential <br />following benefits in water treabnent: <br />. Improves turbidity removal <br />. Improves color removal <br />. Improves taste and odor reduction <br />. Controls chlorination byproducts such as TIHMs and HAAs <br />. Stronger disinfectant than other commonly used disinfectants <br /> <br />.9%. <br /> <br />DOS~=26'~ <br /> <br />Ij :Ill 2.$ <br />Hyper Jon 7SOlA l>o&f:. IDIIL <br /> <br />~roc Dt!a ......ptt <br /> <br /> <br />~",.' <br /> <br />Innovotive Approoches... Pmcticoi Results <br />