When assessing the quality of your water supply, it’s important to understand the contaminants present and how they impact your home and health.

The following list includes the 6 most important things which determine water quality and what water treatment recommendations would solve them.

Total Hardness

This is the sum of the calcium and magnesium present in water.

  • Hard water has excessive amounts of calcium and magnesium in water, making it difficult for soap to properly clean. Hard water will often leave residue behind on dishes and clothing.
  • Hardness causes deposition of calcium carbonate (scale) on heating surfaces and can even clog pipes, valves, and screens over an extended period of time.
  • Water with a total hardness exceeding 10.5 grains is considered to be very hard water, while water below 3.5 grains is soft.

Total Dissolved Solids

Total dissolved solids (TDS) is the amount of dissolved material in water.

  • The biggest contributors to TDS are minerals such as calcium, magnesium, sodium, potassium, bicarbonates, chlorides, and sulfates.
  • Depending on the location that the sample is taken, some metals and organic matter may also contribute to total dissolved solids.
  • While TDS is a good measure of the overall quality of the water, it is a single description and does not indicate the relationship between ions, or if the water is safe to drink.

Turbidity, or cloudiness, is an aesthetic quality of water defined by the degree to which light is scattered as it passes through a water sample.

  • Turbidity is caused by suspended solid material and can be attributed to many different contaminants, including soil, clay, organic matter, and metals.
  • Experts measure turbidity using a nephelometer; turbidity is described using nephelometric turbidity units (NTU).
  • Turbidity is often a direct indicator of water quality and a turbidity below 0.50 NTU is desired for drinking water.


Iron in drinking water is not harmful to human health; however, a high amount of iron can cause an unpleasant metallic taste or odor.

  • Iron can also stain clothing, plumbing, or dishes reddish-brown as the water that carried it evaporates and the iron oxidizes.
  • Abundant levels of iron will allow certain species of bacteria to thrive. These iron bacteria form a biofilm that discolors surfaces and can clog pipes and valves.
  • The ideal range for iron is less than 0.05 ppm (parts per million).


Lead is typically present in water at some level due to industrial waste or lead plumbing.

  • Lead has a long list of negative health effects associated with exposure to it, including lowered IQ and an inability to focus, behavioral problems, hypertension, and kidney problems.
  • Children and pregnant women are at a particularly high risk when exposed to lead, as their bodies will absorb lead more easily.
  • No amount of lead in drinking water is desirable but an amount under 5 ppb (parts per billion) is considered safe.


Chromium is a heavy metal that exists in two forms – chromium III, an essential nutrient, and chromium VI, which is extremely toxic to the human body.

  • People living near sites where chromium is produced or disposed of are at the greatest risk of consuming contaminated water.
  • Chromium VI is known to be a carcinogen and has a negative impact on almost every organ in the body.
  • Testing requires a laboratory analysis, and a total chromium level of less than 10 ppb (parts per billion) is desirable for drinking water.

EPA Regulations for Municipally Treated Water

The EPA standards for maximum contaminant levels (MCL) of the regulated contaminants in the above list are:

  • TDS: Maximum 500 ppm
  • Iron: Maximum 0.30 ppm
  • Lead: Maximum of 15 ppb
  • Chromium: Maximum of 100 ppb

The EPA has a goal of under 1.0 NTU turbidity, but it is not an enforceable regulation.

The EPA does not regulate or provide recommended standards for total hardness in municipal water.

Private well water is not regulated by the EPA.

For more detailed information on the EPA maximum contaminant limits and regulations, including limits for other common contaminants, you can visit the EPA here.

How to Access a Municipally Treated Water Analysis

Public consumer confidence reports for the water quality in your area can be found here.

If you are interested in having more detailed and current data, you can order a water sample analysis kit from Antunes Water to have your water tested by a certified third-party laboratory.