Water Quality Monitoring

Interior Health determines specific monitoring requirements for all water utilities on an individual basis. At mimimum, water systems are monitored once per month for the presence of bacteria.

Interior Health has identified five objectives (referred to as 4-3-2-1-0) for providing water that is safe for consumption. The 4-3-2-1-0 objectives represent the following:

• 4 log (99.99%) reduction in viruses
• 3 log (99.9%) reduction in pathogens
• 2 methods of treatment
• 1 nephelometric turbidity unit (NTU) (a measure of cloudiness)
• 0 coliforms

The ultimate goal is to protect human health. The RDCK works with Interior Health to incorporate the 4-3-2-1-0 objectives into our operations. Most micro-organisms are easily removed from water through disinfection and filtration. By combining methods, a stronger barrier is created for preventing their presence in drinking water. As a result, the risk to human health is reduced.

Interior Health facilitates the sampling, transporting, and laboratory analysis for small water systems. Bacteriological and chemical sample results are stored in the Interior Health Database and can be accessed via their website. http://www.interiorhealth.ca/health-and-safety.aspx?id=11052.

A summary of adverse sample results in RDCK systems can be found in the document attached below. For more information about water quality monitoring please contact the RDCK's Environmental Services Department.

Micro-organisms:

Coliforms (both total and fecal) are commonly found in the natural environment and are frequently used as indicator organisms. If coliforms are present in drinking water, it suggests that fecal contamination of a water source may have occurred. The BC Drinking Water Protection Act requires that drinking water be sampled regularly for the presence of coliforms as well as Escherichia coli (E. coli). These contaminants can lead to severe illness or even death and must be eliminated from drinking water to minimize risk to human health.

Bacteriological analysis is performed routinely to test for total coliforms, fecal coliforms and e.coli. Water is generally considered safe when a sample contains:

• 0 detectable fecal coliform bacteria per 100 ml; and,
• 0 detectable Escherichia coli per 100 ml.

If these levels are exceeded, the RDCK and Interior Health will take immediate corrective actions.

Turbidity

Excessive turbidity, or cloudiness, in drinking water is aesthetically unappealing, and may also represent a health concern. Evidence exists that controlling turbidity is a competent safeguard against pathogens in drinking water.

Health risks increase as turbidity rises, particularly for at-risk populations such as newborns, the elderly, and people with weakened immune systems. Contaminants such as viruses, bacteria, and parasites can attach themselves to the suspended particles in turbid water. These particles can then interfere with disinfection, limiting chlorine’s ability to remove or inactivate the contaminants. Turbidity levels as recommended in the Guidelines for Canadian Drinking Water Quality are as follows:

• >1 NTU - Good
• 1-5 NTU - Fair
• +5 NTU - Poor

Boil Water Notice

A boil water notice is put in place by Interior Health usually when there is an unacceptable level of bacteria or organic material in the water supply.

Who can issue a Boil Water Notice?  Only Interior Health can issue or rescind a Boil Water Notice. No other body or individual has this authority.

What does a Boil Water Notice mean?   When a boil water notice is issued Interior Health informs residents to bring any water intended for human consumption to a rolling boil for a minimum of 1 full minute. Boiling water should kill the bacteria and pathogens that may be present in any given water source. Boiling will not remove any heavy metals, as these contaminants can only be filtered out. The RDCK and Interior Health recommend that all customers drink boiled water or a safe alternative until the Boil Water Notice is rescinded. Water intended for drinking, washing fruits and vegetables, making beverages or ice, or brushing teeth should be boiled for one minute. Boiled water should then be refrigerated in a clean, covered container. Customers could also choose to use bottled or distilled water, or water that has been filtered through a well-maintained treatment device.

To find out if your drinking water system is under a Boil Water Notice go to the Interior Health website: http://www.interiorhealth.ca/health-and-safety.aspx?id=534

Water Sample Results

2011 Adverse Water Sample Results (78.6 kB)