Level 1 | Self-Diagnostic Observational Water Testing

Level 1 Testing is YOU. It is done with simple observations that you can make using your senses of sight, smell, taste, touch, and readily available information about the home. These observations can be observed in the moment or monitored as they change over time. What you see, smell, taste, or problems you are experiencing with your water, your home, or yourself should be noted and recorded. These are basic observations you can make that might help diagnose your water-quality-related problem or condition.

Thousands of contaminants might be present in your water, and it would normally be much too expensive to test for every possible contaminant. However, there are some simple, inexpensive tests, and visual clues that can act as “red flags” for possible contamination or a change in your drinking water quality. With respect to changes in the aesthetic quality of the water, our eyes, nose, and mouth are great detectors and indicators of change. In many cases the aesthetic quality of the water is governed by the secondary drinking water standards. These standards are related to the aesthetic quality of the water and changes in aesthetic quality may indicate a potential adverse change in the quality of the water.

Level 1 | Self-Diagnostic Drinking Water Testing Tool
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Below are examples of Level 1 Self Testing observations that can be made with the senses.


Salty Taste - may indicate an increase in sodium, chloride, potassium, and other salts or a problem with an existing water treatment system (note that water softening adds sodium or potassium to the water).

Metallic Taste - may suggest an increase in acidity, Iron, Manganese, Copper, Zinc, Lead, and other trace metals.

A strong after-taste or alkali taste - high Hardness, Alkalinity, and Total Dissolved Solids.


Discoloration - reddish-brown, brown, or yellowish-brown could be elevated levels of Iron and manganese; a gray color could suggest Aluminum; black or reddish slimy films could suggest a bacterial problem; a bluish-green tint could suggest elevated levels of Copper, Lead, and other trace metals.

Oily Films and Coatings - petrochemical contamination and Biological contamination.

Fizzy Water - may suggest a change in the amount of gases, which may include carbon dioxide, Methane, and other Dissolved Gases.


Musty Odors - presence of fungi, mold, algae waste products, Slime Bacteria, and an elevated standard plate count.

Musty, Earthy, Grassy, or Fishy Smell - algal by-products, fungi, and mold.

Oily Smell - gasoline or oil contamination, possibly bacterial growth.

Fuel Smell - industrial or gasoline contamination.

Chemical Smell - organic chemicals, industrial chemicals.

Fruity Smell - aldehydes.

Sulfur or Rotten Egg Smell - elevated level of Hydrogen Sulfide, manganese, mercaptans (sulfur compounds), organic decomposition, petrochemical-related organics, and Sulfate-Reducing Bacteria.

A hydrogen sulfide odor could be caused by a combination of chemical or biological reactions, i.e., Sulfate-Reducing Bacteria. There is no specific drinking water standard for Hydrogen Sulfide, but there is a secondary drinking water standard for odor and an air exposure standard for hydrogen sulfide gas.

Possible treatment actions for Hydrogen Sulfide and other odors: SW (Shock Disinfection), AER (Aeration), C Filtration (Activated Carbon Filtration), DIS (Distillation System), and Oxid (Oxidation/ Filtration).

Once you've completed an Observational Self-Test of your water, and depending on the results, you may want to further clarify and validate your results by conducting a Level 2 Test.

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