Ka kammala wannan magana: A watan Yuni na shekara ta 1866, wata annoba da ta bazu a yankin East End na Landan ta kashe mutane 5,596, a daidai lokacin da birnin yake kammala gina manyan magudanan ruwa da kuma hanyoyin tsabtace ruwa; ba a kammala sashe na East End ba. An kuma haifar da yawan jama'a a cikin East End, wanda ya taimaka cutar ta yadu cikin sauri a yankin. Masanin cututtukan cututtuka William Farr ya gano Kamfanin Ruwa na Gabashin London a matsayin tushen gurbatawa. Farr ya yi amfani da aikin da John Snow da sauransu suka yi a baya, yana nuna gurɓataccen ruwan sha a matsayin dalilin cutar kwalara a cikin wani
1854 fashewa. A cikin wannan shekarar, amfani da gurbataccen ruwan canal a ayyukan ruwa na gida ya haifar da karamin barkewar cutar a Ystalyfera a Kudancin Wales. Ma'aikata da ke da alaƙa da kamfanin, da iyalansu, su ne suka fi shan wahala, kuma 119 suka mutu.