Testing the water in your household more than once a year may be warranted if:
Test for Coliform bacteria
Test for pH, lead, copper
Test for radon
Test for Corrosion, pH, lead
Test for nitrates, pesticides, and coliform bacteria
Test for metals, pH, and corrosion
Test for chloride, sodium, barium, and strontium
Test for volatile organic compounds, total dissolved solids, pH, sulfate, chloride, and heavy metals
Test for volatile organic compounds
Test for hydrogen sulfide, corrosion, and heavy metals
Test for iron, copper, and manganese
Test for chloride, total dissolved solids, and sodium
Test for hardness
Test for pH and corrosion
Test for Manganese & Iron, Calcium & Iron, Silica
Test for color and detergents