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^`.,,,._...,-- ,�z- Y.h�a,�-�"t'���-x?� ���':''�.�`�"�'y`iz`y?-�n.z �s�"_un•�..; ..��f`z,S�sr; <br /> Removing Total Organic Carbon from Secondary-treated <br /> Wastewater: Available Technologies and Cost Implications from <br /> Chatham, Mass. Case Study , <br /> Alyson B. Watson, P.E., Nathan C.Weeks, P.E. <br /> GHD <br /> Abstract <br /> The need to treat municipal wastewaterto low concentrations of total organic carbon (TOC) is a s <br /> relatively new phenomenon, particularly in the Northeast In 200J, the rvlassachusetts Department <br /> of Environrtientai Pr6t&Li6h( .#9$ P)revised i{s Groundwater pischarge Permit program to include: <br /> TOClimits for treated water dischar ed to a uifers that contribute to otable su lies fhe new <br /> g q p Pp w <br /> limas aim to minimise contamination of water supplies with organic compounds, including <br /> contaminants of emerging concern such as endocnn� disrupting compounds, pharmaceuticals and <br /> personal care,products,and other oFgahic compounds commonly found in ti,eated wastewater In <br /> this sense,TOC concentrations are being used as a surrogate rneasurefnent for the presence of <br /> specific Masses of organic compounds This paper presents an overview of alternatives that may be <br /> Irnplemenfed following secondary wastewater treatment to meet the new TOC limits, and presents <br /> ;cost irrjplicat�ons of meeting ttie ne4v regulatwn�from a recent Chatham,Mass case study. - <br /> r r <br /> Key'Yljords <br /> 'Total organic carbon;Contaminants of emerging concern,'endocrine disrupting Compounds;:. <br /> advanced treatment; Zone II"discharge, Chatham <br /> Introduction Several alternatives that may be used following <br /> secondary wastewater treatment and prior to <br /> discharge to meet these limits are discussed <br /> TOC removal requirements for wastewater below. <br /> discharges are not prevalent in the <br /> Northeast, but more and more TOC limits <br /> are expected to be placed on both surface water TOC Removal Technologies <br /> and groundwater discharges in future years as i <br /> regulatory agencies develop more robust A variety of technologies are being implemented <br /> approaches for minimizing the potential• to reduce TOC concentrations in drinking water, <br /> introduction of specific CECs into the wastewater, and reclaimed water with varying <br /> environment. The body of data regarding effectiveness, including: <br /> approaches to meeting TOC regulations for <br /> treated wastewater therefore continues to grow. • Coagulation and filtration <br /> Among the new standards in MassDEP's revised 0 Adsorption <br /> Groundwater Discharge Permit Program is a • Membrane filtration <br /> requirement that treated water discharged to the 0 Advanced oxidation <br /> portion of an aquifer that contributes water to a <br /> potable well (or a Zone II area, as defined by In wastewater treatment, these technologies <br /> 310 CMR 22.02)with a travel time of greater would be implemented following secondary <br /> than 2 years to the supply source must comply treatment to reduce TOC to acceptable <br /> with a TOC limit of 3.0 milligrams per liter concentrations. <br /> (mg/L). This standard becomes more stringent(1 <br /> mg/L TOC)for discharges with travel time of less Coagulation and Filtration <br /> than 2 years. <br /> In removing TOC through coagulation and <br /> filtration the physical or chemical properties of <br /> 28 The NEWEA Journal Winter 2010 <br />