J.M.
Hi Stef:
Because our cities lack really clean water. Water without lead,it is best, to boil all your water and then keep it in the frig for the days formulas.Even if your water has been tested to have little lead, your pipes throughout your home may produce to much lead,to be safe for your baby. Regular drinking water from your market , is not much better than tap,matter of fact it has no floride in it.If you find it easier, to purchase water, go for sparklets drinking water. I wish you and your growing baby the best.