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Federal-Register / Val: 45 No. 21Z /."Thur'sd'ay;,October- 30 198b / 'Propoaed`Rirles 7203 ` -
<br /> the National IirteriirfPrimary Drinking level'for chromium in-drinking water comments:and'after.a�wadequate
<br /> Water standards are for totatchromium and have indicated`explicitly-that tite_, supportive":data=base'is-available .. '
<br /> This is because preAreatment:of_ standard:is for_hexav lent chromium'. C.Incingrat.16n of Clirom hum CAntatnmg.
<br /> drinking,water byc-hlorination"may,. (WHO,.1970 IVAS;1977;Sorg,'1479 Wastes
<br /> result in okidation.of trivalent (describing Japan's driiikmg water,
<br /> chromium.:(Guidelines.for Canadian- standard for hexavalent chromium):) The,Agency.�conteniplates%regulating
<br /> Witter Quality,1978;S6rg;.1979 .U:S . Since the underlying drinking,water wastes:::whiclr.contain:both-tri-•and:
<br /> EPA,1976.)Total chromium is-thus thew standard in fact reflects human health hexavalent chromium in one
<br /> appropriate parameter:(U.S EPA;1976:) and environmental dangers'of" circumstance,s namely_-when a: .
<br /> All chromium-compounds also are 'hexavalent chromium;we feel justified chromium=bearing,wasteAs.incinerated
<br /> regulated as toxic under the,Cle'an, in retaining this:.starrdard.when or destructhrely.-oxidized by a similar,,
<br /> Water.ACt(CWA),In.part,,this.reflects. regulating solely-on the basis of process::Such,control;is'necessary
<br /> the Congressional-determination to,list- hexavalent chrome.. because-trivalent cl roniiumsoxidizes to
<br /> all chromium compounds.as_'toxic` I We stress that under ourproposal,all hexavalent chromium.during,
<br /> pollutants under:CWA.Section'307(a)(1). wastes are.to.be:#es#ed.for:the incineration=.(U:S.Dep
<br /> j.
<br /> In addition,the AdministratorRas:'a characteristic of EP'toxicity based ort= 1979).Incinerated-wastes:containing;
<br /> great deal of flexibility n making listing; hexavalent chromium'wlien the trivalent chromiumethus-should be:
<br /> (or delisting)determinations under' amended-characteristiais'finalized We^' regulated as ifahey=ntain=hexavalent.
<br /> CWA:Sectibn;307 He is to consider a wish particuistrly"to`clarify:this-point chromium.The,,AgencyJntends;in the.
<br /> rseries zof'enumerated'fictbrs„to.assign because of other regulatory,action taken near..future to-adopt.appropriate.
<br /> appropriate weiglit to.eacli,and;to today delisting certaiii chromium- regulations under Parts 261 and 266
<br /> arrive at a final determination by bearing wastes and.`granting;�temporary regulating,these-fypes o€-chromium
<br /> balancing-the:different.e'lements..The: exclusions from hazardous-waste status bearing wastes.Regt ilatbry:aotiorris'
<br /> identification°process_'under.,RCRA is= for.other such wastes'(published being-deferred at.the-preserit time;
<br /> muchlessilexible'and is to some extent elsewhere in•Part XLof this-issue). however,due to the:need to,implement
<br /> more stringent,in light of the` All-of.these_wastes.will be-subject.to. other parts:of the°hazardous:waste
<br /> significantly more'impactive: the amended EP toxicity characteristic:: management program;and:also because'
<br /> consequences of a RCRA hazardous ' and generators of these wastes incineration of trivalent chromium-
<br /> wastedetermination..Thus,.,wastes:are consequently will'have-to'test=their containing wastes does.not appear to lie
<br /> not.to be-identified"as iiazardous_unl'ss- wa:ate extracts for the`presence-of widespread,'limiting the Possibility of'-
<br /> they are capable of posing-a, hexavalent chromium: environmental.insult during this interim
<br /> "substantial"hazard to human1ealth-or B.ProposedAnalytica];MV th`od period.Furtliermore,the Agency needs
<br /> the environment.In light of these Distin more-time.ta'develbp regulatbry,
<br /> grlent-* Chromveen>7ii=-and-` standards to apply to facilifie's
<br /> differing statutory-schemes;regulatory- Hexavalent�C.hromirr�ri� incinerating trivalent chromium-
<br /> action affecting,chromium�ontainiatg
<br /> wastes liasno-directb`earinzwrthe` The proposal to amendtlie E1�'toxicity containing wastes.For these.
<br /> characteristic to apply,only,to, we are not ro o ”
<br /> status of-chromium as a toxicgollutant p p smg,any,standardi-for
<br /> under CWA Section 307(x): hexavalent ehrnmrumsegitires,tlr8t=thE!re' in�eration oftrivalent'clirorniurrr>
<br /> be an analytical method which containing-wastbs'at'this time.
<br /> H.Regulatory Actiari.. distinguishes between tlieise'two, EPA is,however,anxious Wobtaiir .
<br /> A.Propmal_To,Amend the- valence'�statbs.EPA's Cfftce:of_Rb8earcl = comments on this contemplated
<br /> CharacteristicbfEP Toxicity and`Developnrent-has`develope`d such'a. approach.We specif ealry solicit '
<br /> procedure.The method(fully:described: comments to the following questions:.
<br /> In.order.to.reflect the differing in Appendix A t&tliis>preamble);;is 1.When incineration of chromium=-
<br /> environmental.hazards posed'fiy: based..on.ti e,separation.of,hexavalent containing;wastes:causes-oxidation.of_
<br /> trivalent and hexavalent chromchromium from solution by the ,
<br /> containing chromium= chromium
<br /> wastes:when-disposed on. coprecipitation of lead chromate.with sThere also,is.one.other:situation.where,wastes-
<br /> land,".theAgency:is-.proposing to amend lead:sulfate;ai:a pH:of-3.5:The. might be regulatedbased on total chromium:The
<br /> the extraction procedure to'apply-to^ , precipitateis-resolubilized iri nitric'acid Agency,still hassome.concern that trivalent. ..
<br /> hexavalent,-chrome instead of,4b total and`gnantified by--atomic absorption chromium from waste disposal sites could migrate
<br /> to public water systems where it would be oxidized
<br /> chromium.We•are,.--not;however,-, spectroscopy.Since trivalent chromium during chlorinatibn td-the hexavalent state:We.,
<br /> proposing;to chang.p1lle'maxim'inrl, d'oes'irot precipitate unYler'suchbelieve the likelihood of this.occurring to.be remote
<br /> concentration:le'vel`of Hexavalent conditions,_the method`offers a means.of', in light of.the,low migr_'atory-potential-of trivalent.
<br /> chromium in the.EP extract,which determining thepresence and' chromium.Idowevei,shculd'migration of;hivaleni
<br /> would conse uentl -.remain.at:5:0 m l:. concentration.of.the hexavalent state-in chromium ionfios sm icient waste fere s b tantia ly-
<br /> q_ Y mg/j, concentrationssufficient to interfere substantially;
<br /> Thislevel is.based.on.the:National admixture with the trivalent form: with'treatment of public water systems,or
<br /> Interim Primary Drinking Water.. Comments.are solicited on:the. otherwise cause public health concerns,we view
<br /> Standard,,whichtwas-estalilished"tb application of this method'to EP' om imminent hazar'd guthorityuridhr-sectiom7tmsr
<br /> of RCRA as sufficient to enjoin further-'
<br /> reflect`=the knOWritOXICrty-Of`the extracts— contamination:We are also.preparedin this
<br /> hexavalent form.4(Sorg 1979;U.S:EPA;, This method has been evaluated'Using circumstance.to exercise our listing authority;under,
<br /> 19764`5 Csther cbuntxies-and' effluents containing higli concentrations Subtitle C_waddress the.particular.site:creating the:.
<br /> organizations also have adopted this. of orgardcma' rials samplewwhere- problem-
<br /> matrix interferences have been
<br /> ?For example,,th'e tanningrindustry,�a.principal.-•.
<br /> _ generator of 4rivalent chromium-bearing wastes,,
<br /> 'The maximum concentration level of the EP: eriCouIitered'with the more..usual, does`not presently incineratesny of:ifs wastes;.
<br /> toxicity characteristic,of course,is established at j chelation/extraction Procedures:]l`&ther although- few individual tanneries;and'the=
<br /> two orders of magnitude above the Dr"inking Water evaluationprEaelltly iS bE ing conducted':`. Tanners'GCbimcil`in coltaiioratio'mwIth th@ II.$:
<br /> Standard: Sureau.of Mines are investigating the feasibility of
<br /> 5As;noted'above;the stAndard-also'establishes a' with a wide'Variety>of:industrial wastes waste incineration.(U.S.Dept.of Interior;1979)'
<br /> margin of safety in light of oxidation ofxhromium as- and.EP extrarts::TheprocEdure':will b'es Several POTw's'do,-hbweven use'the>zimpro
<br /> a resulf of°drinkingwater:tieatfteni{96tg 9701.�: finally promulgated after review oL' process to iricinerate'tannery-sludges..
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