Understanding Water Quality Results

"The only way you can be sure your water supply is safe is to have it tested."

Water Testing

It is important to regularly test your well water for bacteria and a standard set of chemical and physical parameters. The term “Parameters” refers to the minerals, chemicals, bacteria, etc. that are tested in a water sample. Use an accredited water testing laboratory.

Appropriate water sampling bottles and instructions on proper sampling may be obtained from your nearest Service New Brunswick location, the New Brunswick Analytical Services laboratory, or a private laboratory.  The cost of analyzing water samples can range from $6 for a single parameter to $130 or more for a full set of chemical parameters. The cost can vary depending on the lab and the number of parameters being tested.   Many labs offer water quality analysis packages that are usually less expensive than testing for individual parameters. These packages provide more information which allows for better interpretation of water quality results and assessment of water treatment requirements.

Please refer to the New Brunswick Drinking Water Quality Guideline list for recommended parameters to test in your water supply. These parameters are recommended because:

• Their presence may interfere with the removal of parameters that may affect your health.
• They may affect the type of treatment you select for your water supply or the treatment system’s effectiveness.
• They may be indicators of overall water quality.

Special Tests

Some parameters are not included in the general chemistry or metals analysis. If you suspect that hydrogen sulphide, iron bacteria, sulphur bacteria, and radium may be present in your water, then you may wish to request testing for these parameters.

Drinking Water Quality Guidelines

The province of New Brunswick adopts the Guidelines for Canadian Drinking Water Quality to evaluate the quality of drinking water in New Brunswick.

Private Water Supplies

Upon receiving the lab results of a water test, private water supply owners may be advised of the presence of health concerns.   Since these are privately owned and operated systems, it is up to the well owner to treat their water or choose an alternative supply to ensure their safety.

Regulated Water Supplies

Municipally and provincially owned and operated water systems are required to sample their water according to the Clean Water Act  Regulated water supplies must test for the specific parameters in the Drinking Water Quality Guidelines list.  Regulated drinking water that exceeds these limits will be subject to a health risk assessment which may result in the issuance of an interdiction( in the form of a boil order, do not consume order, or other directive), to ensure the safety of citizens.

Technical Terms for Interpretation of Water Results

Maximum Acceptable Concentration

The Maximum Acceptable Concentrations (MAC ) is a level that has been established for certain substances that are known or suspected to cause adverse health effects.

Aesthetic Objective

The Aesthetic Objective (AO) is established for parameters that may impair the taste, smell, or colour of water; or which may interfere with the supply of good quality water. They do not cause adverse health effects.

Detection Limit

The detection limit is the lowest concentration of a chemical that can be reliably measured. It may be referred to on a lab report as DL, RDL (reporting detection limit), or RL (reporting limit), or LOQ (limit of quantitation).

The detection limit depends on the equipment used for analysis and the method of analysis. It can also be affected by the concentration of other parameters present in the water. For example, if the concentration of calcium is very high, it can elevate the detection limit of another parameter. To compare the concentration of a parameter to the Canadian drinking water quality guideline (if one exists), the detection limit must be less than the guideline.

Some labs do not report the detection limit. However, you can still determine the detection limit used for each parameter from the lab report. For example, if the detection limit of a parameter is 2 mg/L and the level of the parameter is below the detection limit, the result will be listed as “< 2” (less than 2 mg/L).

If the detection limit is greater than the guideline, you should consult the laboratory where the analysis was done. The laboratory will inform you of the options available for reporting the parameter of concern with a lower detection limit.

Units

Laboratories may report the concentration of parameters in milligrams per litre (mg/L) or micrograms per litre (µg/L or ug/L). There is a BIG difference: 1 mg/L is equal to 1000 µg/L.

When looking at the results from a lab and comparing them to previous results, or to the results from a different lab, or to the Guidelines for Canadian Drinking Water Quality, it is important to make sure that the units are the same.

1 mg/L = 1000 µg/L (micrograms per liter)
1 mg/L = 1 ppm (part per million)
1µg/L = 1 ppb (part per billion)

Interpreting Water Quality Results

When a water sample is analyzed at the Provincial Analytical Services Laboratory, all parameters that exceed an MAC or AO are submitted to the regional Health Protection branch office.  Public health inspectors will send information to homeowners explaining the health effects of any parameters that are exceeded.  You can contact your local Health Protection branch office to help you interpret your water quality results.

In general, you should compare the results of your water quality analysis to the MACs or AO for each parameter. Some labs will identify the parameters that exceed the guidelines for you.

• If your water exceeds a Maximum Acceptable Concentration (MAC), take action to eliminate the problem or install treatment.
• If your water exceeds an aesthetic objective (AO) such as iron or manganese, you may choose to treat your water for two reasons:
  • to prevent staining, scaling, or corrosion of plumbing fixtures and appliances
  • to make it more pleasing to consume

Treatment

The Department of Health recommends purchasing a treatment system that has been certified to meet the current NSF standards. NSF International is a not-for-profit, non-governmental organization that sets health and safety standards for manufacturers in 80 countries.

Once installed, test your treated water to ensure that the treatment system is working properly. Maintain the system according to the manufacturer’s instructions to ensure a continued supply of safe drinking water.

Health Concerns

Health effects for parameters that have an MAC or aesthetic objective are outlined in the New Brunswick Drinking Water Quality Guidelines list for regulated water supplies in New Brunswick. Please refer to the Health Canada website for a complete list of the Guidelines for Canadian Drinking Water Quality, the science behind their development, and health effects. If you have concerns that you or your family has been exposed to elevated levels of any parameter in your drinking water, you should seek medical advice.