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Imisebenzi Yokudonsa: Ukuhlanza kwePltsburgh PCB

Source: UJim Gordon Izindaba ze-Clearwater nama-Bulletins

Ukuphothulwa kwephrojekthi ye-PCB dredging eduze neChibi Champlain ePlattsburgh, NY, kukhombisile ukuthi ama-PCB angabizwa ngokuphepha eMfuleni i-Hudson. Eduze kwechibi laseLake Champlain kunemizi ebingasaphazanyiswa amanzi, amabhishi okubhukuda nezimoto ezilandelwayo zihlala zivulekile ngesikhathi kuqhubeka le nqubo yeminyaka emithathu, kanti nalabo abebengabazi manje ngokudanisa manje sebewuncoma lo msebenzi.

'Bengingahambisani nakho ekuqaleni. Bengikhathazekile ngokuvusa izinto phezulu. Akuzange kube nomqondo omkhulu kimi, 'kusho uDkt. Djell Dahlen, udokotela ohlinzayo wamehlo ondlu yakhe ebizayo eseduze nendawo eseduze nolwandle engamahektare angama-34 eCumberland Bay. 'Njengomakhelwane oseduze, lokhu akuzange kungikhathaze kancane.'

'Amadada ahlala phansi lapho kusabheda khona,' kusho uBill Ebert, umphathi wesiza sonjiniyela wephrojekthi i-Earth Tech Inc. Isiza siseduze kwamabhishi amadolobha nezwe, kanye nama-motels. Amabhishi ahlala evulekile. Izimoto zivulekile. Konke kuqhubeke ngokujwayelekile, 'kusho yena. Umsebenzi wokumba kabusha uqhubeke amahora angama-24 ngosuku, kepha awutholanga zikhalazo, kusho u-Ebert. 'Kwesinye isikhathi abantu abebekuma-patio abo asemotel babekuqhweba.'

Ukuhlanzeka kwe-PCB eLake Champlain kubandakanya zonke izinselelo ezifanayo nokusebenza kokudonswa phansi kweHudson kuzobandakanya, nokho kwaqedwa ngesikhathi, ngaphansi kwesabelomali, ngaphandle kokuvusa izinto ezingcolisayo. Ukusebenza kususe amakhilogremu we-25,000 we-PCBs ehlanzekile, kunciphisa ukungcoliswa okusendaweni ngamaphesenti angaphezu kwe-90, ngenkathi ethola ukunconywa komakhelwane.

Leyo mpumelelo kungaba lula ukuyiphinda eMfuleni i-Hudson, ngokusho konjiniyela bephrojekthi ababengamele ukudilizwa ePlattsburgh. 'Ubuchwepheshe bukhona ukukwenza kahle, kufanele nje ubusungule bese ubulawula,' kusho uLech Dolata, ongunjiniyela woMnyango Wezemvelo Wokulondolozwa Kwezemvelo. 'Okusemqoka ukuthi, ukudala kabusha kuyasebenza.'

UDolata ukhombise indlela elula kodwa esebenza ngempumelelo yokususa i-PCB-laden sludge. Umkhumbi wokuphinda omncane kakhulu, obude obungama-20 ubude, ubekwe kusetshenziswa izixhumanisi zomhlaba wonke ezisebenzisa i-satellite (GPS) ngqo kulayini oyifunayo, futhi ukusebenza kuqhutshwa kumabhidi kusetshenziswa izintambo ezidonswe enkambeni efiselekayo yokuhambisa imbila. Umsebenzi ubushelelezi kakhulu, izilwane zasendle futhi omakhelwane abakuboni kangako.

Ngaphansi kobuso, isisetshenziswa esinjengemitha engu-8-ububanzi sigqekeza udoti bese siwuphoqa ngaphakathi, lapho ipayipi lokuthambisa lisinamathisela esitsheni esimboziwe. Amakhethini kasilika neminye imigoqo engaphansi kwamanzi igcina noma ikuphi ukufiphala okuboshwe ngaphakathi, kepha ePlattsburgh bekungekho okuvusa amadlingozi okuncane kunoma yikuphi.

IGeorgia Pacific Corporation isebenza nge-valve yokudla ngaphakathi kwamamitha amahlanu wesiza esisodwa sokucekela phansi, futhi idinga ukucaciswa kwamanzi ngaphandle kwezingxenye ze-2 ngebhiliyoni yezinhlayiya ezimisiwe. U-Ebert uthe ama-dredge opharetha ahlolwa njalo, kepha ahlala egcinwe ngaphakathi kwezidingo eziqinile, futhi i-valve yayikwazi ukuhlala ivulekile kuyo yonke inqubo yokukhuculula.

Lapho nje udosi luthathelwe amazolo ukuze linciphise isisindo salo futhi lwahlolwa ubuthi. Ukudukelwa okuyingozi kusuka ePlattsburgh kuthunyelwe eBuffalo ukuze kuyoshiswa, kuyilapho udoti ongcolile ongcolile ubususelwa elalfini eQuebec. Amanzi la aphathwa abuyela eLake Champlain. Uvivinyo lukhombisa ukuthi ihlanzekile ngokwanele ukukala njengamanzi okuphuza.

IGeneral Electric, okuyinkampani ebhekele ukungcola kwe-PCB okwenza iWordson ibe yindawo yenhlangano eyi-Superfund, ithi ukufakwa phansi kwempahla kuzophazamisa ukusebenza komfula futhi komise nomnotho wendawo. I-GE njengamanje isebenzisa izigidi zamadola ngesonto ezikhangisweni zethelevishini ziveza izindawo ezinkulu ezidonsa ngodaka. Kepha ngokusho kweziphathimandla ze-EPA ne-DEC, ama-clamshells awokuzulazula, hhayi awokuzungeza kwemvelo, futhi awanakwa uma kucocwa ubuthi be-GE obuphonswe emfuleni. Ngaphansi komthetho wobumbano, umdondoshiya wezizwe zonke unesibopho sokukhipha ubuthi, i-GE ebizayo ayifuni ukukhokha.

Ngenkathi uGeneral Electric elahla amakhilogremu ayisigidi noma ngaphezulu ama-PCB emfuleni, awabekiwe wonke endaweni eyodwa, kepha asabalala ngaphezu 'kwezindawo ezidonsela' ezingama-40 emfuleni phakathi kweGlens Falls ne-Albany. I-toxin isuka kulezo zindawo, ingene ochungechungeni lokudla, kukholamu lwamanzi, odakeni olusogwini nasemoyeni. Imishini yokudonsa izokalwa ngezidingo zosayizi wendawo ngayinye eshisayo. Izinsimbi zokufaka amanzi entweni yokuhlanza kanye nokuhlanza amanzi zingafakwa ngamaloli zingene nangaphandle kwezindawo lapho zidingeka khona, zilingisa inqubo esetshenziswe ePlattsburgh. Azikho izindawo zokwelashwa ezihlala njalo ezizodingeka.

I-USEPA ikulungele ukumemezela isinqumo maqondana namakhambi ayo wokungcola kwe-PCB okuphendule uMfula i-Hudson waba yisiza semfucumfucu esinobuthi esikhulu kunazo zonke eMelika.

ICumberland Bay esePlattsburgh ngaphakathi kweLake Champlain kwakuyindawo yaseClass Two Superfund, eyayibeka engcupheni impilo yabantu nemvelo. Ukugxilwa kwe-PCB kulinganiselwe izingxenye ze-2000 ngesigidi. Ukuhlushwa kwe-50 ppm kuthathwa njengokuyingozi ngokusemthethweni. Ukuhlanzwa kwe-PCB eLake Champlain kunciphise ukugxila kwaba yisilinganiso se-10 ppm.

Indawo yayihlanganisa amahektare ayisishiyagalombili amaxhaphozi nama-50 amahektare angaphansi kwamanzi echibi, lapho ama-PCB ayeqongelele khona. Njengoba umsebenzi uqeda futhi kususwa imishini, uPlattsburgh unquma ukuthi indawo leyo kuzoba umgwaqo wesikebhe, noma mhlawumbe ipaki. UDkt Dahlen, ohambe nesikebhe esimnandi nabasebenzi abavela ekusebenzeni okonakele, ehleka usulu wathi uncamela ipaki esiteji sesikebhe, kodwa wengeza nokuthi ngabe yikuphi okuthandwa yindawo enobungozi.

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