Up to 20 million tube wells were dug in Bangladesh, Vietnam, Laos, Burma (now Myanmar), Thailand, Nepal, China, Pakistan, Cambodia, and West Bengal, India.
Nii kaevatigi Bangladeshi, Laosesse, Vietnami, Birmasse (praegune Myanmar), Taisse, Nepali, Hiinasse, Pakistani, Kambodžasse ja Indiasse Lääne - Bengalisse 20 miljonit sügavat kaevu.