The creek 's nitrate concentration ranged from 3.3 to 6.3 milligrams per liter for filtered water .
The concentration of sulfates ranged from 23 to 29 milligrams per liter , again for filtered water .
The creek 's nitrate concentration ranged from 3.3 to 6.3 milligrams per liter for filtered water and the concentration of sulfates ranged from 23 to 29 milligrams per liter , again for filtered water .