Complex sentence: Chakraborti has criticized aid agencies, saying that they denied the problem during the 1990s while millions more tube wells were sunk, and later hired foreign experts who recommended treatment plants which were not appropriate to the conditions, regularly breaking down or not removing the arsenic.
Split into simpler sentences: Chakraborti has criticized aid agencies, saying that they denied the problem during the 1990s while millions of tube wells were sunk. The aid agencies later hired foreign experts, who recommended treatment plants which were not appropriate to the conditions, were regularly breaking down or were not removing the arsenic.