Rawgroundwater from the familywells andwater used for drinking
(i.e. sand sand-filtered or untreated water) were collected for each of
the studied households. Tube well water was pumped for about
5–10 min to remove water at the tip of the tap and then samples
were collected. In Dan Phuong (R2), Hoai Duc (R3), and Ly Nhan (R4),
sand filters for iron and arsenic removal are very common. Filtered