Complex sentence: Complementing the National Water Policy and the National Policy for Safe Water Supply and Sanitation, both of 1998, the government adopted a National Policy for Arsenic Mitigation in 2004.
Split into simpler sentences: Complementing the National Water Policy, the government adopted the National Policy for Safe Water Supply and Sanitation in 1998. In 2004 it also adopted a National Policy for Arsenic Mitigation in 2004.