The symptom is not always the answer.

Confirm before you buy

Nearly every expensive mistake in water treatment comes from the same place: equipment chosen against a suspected problem rather than a confirmed one. A softener bought because of a lead worry does nothing about lead. A carbon filter bought because of nitrates does nothing about nitrates. Both then cost money at every cartridge change.

Confirmation is usually cheap and sometimes free. Several of the problems below are settled by a two minute test at your own sink, using nothing but a clear glass. Others need a test strip. A handful need a certified laboratory, and for those, how the sample is taken matters as much as the analysis.

Problems you can see, taste, or smell

These announce themselves. The risk with this group is misreading the symptom, because several of them look similar and need opposite treatment. Orange staining and blue-green staining are both metal deposits and they have nothing else in common.

• Hard water. Dissolved calcium and magnesium picked up from limestone and other rock. Confirm with hardness test strip or titration kit, in grains per gallon.
• Chlorine and chloramine taste. Utilities add a disinfectant residual and are required to maintain it through the distribution network. Confirm with free and total chlorine test strip, plus the utility report for the disinfectant type.
• Iron and rust staining. Iron dissolved from rock or from corroding pipe. Confirm with laboratory iron panel, distinguishing dissolved from oxidised iron.
• Sulfur smell. Hydrogen sulfide gas, which smells of rotten eggs. Confirm with laboratory hydrogen sulfide test, after isolating hot from cold.
• Sediment and cloudy water. Sand, silt, rust flakes, or air. Confirm with glass settling test, then a turbidity reading if it persists.
• Low pH and blue-green stains. Acidic water dissolves copper from the pipes it passes through. Confirm with ph meter or strip, plus a laboratory copper test.

Problems with no symptoms at all

This group is the reason testing exists. None of these can be seen, tasted, or smelled at the concentrations that matter, so there is no point at which your senses will tell you to look. Every one of them needs a laboratory result, and on a private well nobody will produce that result unless you ask for it.

• Lead in drinking water. Lead does not normally come from the source water. Confirm with certified laboratory analysis of a first-draw tap sample.
• PFAS. A large family of manufactured fluorinated compounds used in firefighting foam, non-stick coatings, and industrial processes. Confirm with certified laboratory analysis using an epa-approved pfas method.
• Bacteria in well water. Private wells are not regulated the way public supplies are, and no one tests them but the owner. Confirm with laboratory total coliform and e. coli test, annually at minimum.
• Nitrates. Nitrate enters groundwater from fertiliser, manure, and septic systems. Confirm with laboratory nitrate-nitrogen analysis.
• Arsenic. A naturally occurring element in bedrock across parts of the Northeast. Confirm with laboratory arsenic speciation analysis.
• Radon in well water. Radon gas dissolved in groundwater. Confirm with indoor air radon test first, then a laboratory water radon test if indicated.

City water and well water are different situations

If you are on a public supply, a great deal of work is already being done on your behalf. The system is monitored against federal and state limits, and it publishes an annual report showing what was found. Your remaining questions are usually about the pipes between the main and your tap, which the utility does not own and does not test.

On a private well there is no monitoring, no report, and no regulator. Everything starts from a laboratory test you arrange yourself, and the recommendation is to repeat it annually because wells change with rainfall, with land use nearby, and with the age of the casing.

Our guide on reading a water quality report covers the public water side, and city water against well water sets out how the two situations differ in practice.

When the honest answer is to do nothing

Several of these problems have a resolution that involves buying no equipment at all. Cloudy water that clears from the bottom upward is dissolved air and needs nothing. A rotten egg smell on hot water only is usually the water heater anode rod rather than the supply. A sudden orange tint on municipal water is often hydrant flushing and clears in days. Nitrate below the limit in a household with no infant calls for annual monitoring rather than a system.

Every problem page here carries a section on when not to treat, for exactly this reason. We would rather you spend nothing and be right than spend money on equipment that addresses a problem you do not have.

What happens on a water test visit

We test at the tap for the parameters that change a recommendation: hardness, chlorine or chloramine residual, pH, iron, and total dissolved solids. Where you are on public water we pull up your utility's most recent report and read it with you, because the rows that matter are rarely the ones that stand out.

We will also tell you what a field test cannot do. It does not detect PFAS, it does not confirm lead, and it does not culture bacteria. When your question is one of those, the useful outcome of the visit is a correct sampling plan and a laboratory referral, and you keep the written results either way.