Kwangathi 1990
Source: Irekhodi le-Engineering News
Iziphathimandla zezemvelo eMassachusetts zisebenzise amaRandi ayizigidi eziyi-14 ukukhipha nokushisa “indawo eshisayo” yama-biphenyls (ama-PCB) ane-polychlorine ezansi kwechweba laseNew Bedford. Ukuhlanzwa kuhlanza indawo esendaweni engamahektare amahlanu echibini lomfula i-Acushnet lapho kugxilwe khona cishe ama-5% amakhemikhali asethekwini kanye nokungcola kwensimbi esindayo.
Itheku lamahektare ayi-1000 linama-PCB amaningi kakhulu ezweni futhi lingelinye lamasayithi amabi kakhulu ohlwini lweSuperfund National Priorities List. Ukudonsela "indawo eshisayo" kuhloswe ngayo ukunqanda ukufuduka kokungcola kungene ethekwini lonke.
Isigaba sokuqala sokuhlanza, esaklanywa yiCorps of Engineers, sasihilela ukumba cishe i-10,000 cu.yd. phansi kwesiziba ekujuleni okuphezulu kwe-4-ft usebenzisa i-Ellicott® I-Brand Series 370 cutterhead dredge eqhutshwa yi-AGM Marine Contractors ezonciphisa ukusakazeka kweziduli. Izinto ezibunjiwe zizofakwa ngepayipi elintantayo elingu-3,000-ft liye endaweni yokulahla evaliwe emaphethelweni wamanzi eNew Bedford.
Okokusebenza kuzongeniswa ngamanzi, bese kuphuma indle kusuka emanzini kuzosuswa ama-PCB nezinsimbi ezisindayo ngaphambi kokukhishelwa ethekwini. Inhlabathi enamanzi izobe isishiswa ngomlilo, ibhubhise ama-PCB. Umlotha womlilo oqukethe izinsimbi uzoqiniswa, ungcwatshwe futhi uboshwe kule ndawo okwesikhashana. "Ukulahlwa kwalo ekugcineni kuzoncika ekutheni lonke itheku lihlanzwa kanjani," kusho uMark Otis, ongunjiniyela wezokwakha ehhovisi leCorp eNew England eWaltham.
Uhlelo lokudilizwa kabusha “kwendawo eshisayo” nokulahlwa komhlaba kulandela ucwaningo lomshayeli olwalufaka ukufaka indle engcolisiwe emgodini ojulile phansi ethekwini nokuyifaka ngento ehlanzekile. "Asiphumelelanga ekutholeni ikepisi elihlanzekile ngempela," kusho u-Otis. Kodwa-ke, le ndlela ingahle ihlanganiswe nesigaba sesibili sokuhlanzwa kwechweba, kusho okhulumela i-US Environmental Protection Agency.
AmaCorps aqala isigaba sokuqala sokuhlanza ukuphela kwe-1991.
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