Agriculture

Water Safety 

Water Safety     

Water is essential in the food industry as an ingredient or as part of a process. Food processors require large quantities of water for different operations, including: food manufacturing, cleaning, ice making, steam production and product transport. Food processors must ensure the water and water systems in their facilities are safe and meet national quality standards.
 

Water Standards  

All water used in processing must meet national water standards under the  Guidelines for Canadian Drinking WaterHealth Canada plays an important role in water quality and safety standards, such as regulating the safety and quality of prepackaged ice and water used in food processing.  
 

Water Regulations 

The Canadian Food Inspection Agency (CFIA) and provincial health authority verify compliance with and enforce food safety standards, including water safety.  
 
Water in Canada is regulated under the following acts and regulations: 

For details on these specific acts and regulations please refer to the Canadian Food Inspection Agency (CFIA) - Acts and Regulations website

Manitoba Acts and Regulations include:

Water Sources 

Most food processors use water from city and municipal suppliers or from wells. Processors are responsible for ensuring the quality of their water supply using a water testing system. The CFIA recommends processors test their city, municipal or well water supply twice a year to ensure it meets provincial and national quality standards. Processors who use water from rivers or other sources must ensure the water supply is properly treated and that it meets provincial and national quality standards.
 

Water Contaminants 

Water contaminants in processed food, including biological, chemical or physical agents, can affect the health of consumers.
 
Biological Contaminants: Enteric pathogens (bacteria, viruses and protozoa) are the main source of biological contamination. They can exist naturally or can occur as a result of contamination from human or animal waste. Bacteria will not multiply in water if the water does not contain a source of nutrients.
 
Waterborne pathogens include:  
 

Bacteria

Aeromonas, Campylobacter, Coliforms*, E. coli 0157:H7, Legionella,  Salmonella, Shigella, Yersinia, Vibrio

Viruses

Enteroviruses, Hepatitis A,  Noroviruses

Protozoa (parasites)

Amoeba, Cryptosporidium, Cyclospora,  Giardia, Roundworms, Toxoplasma

 
 
 
 
 
 
 
 
 
 
 
 
*Coliforms are a group of bacteria found in human and animal fecal material, soil and untreated environmental water. This group includes strains of Escherichia (including E. coli O157:H7),  Klebsiella, Enterobacter and Citrobacter.
 
It is easy to destroy coliform bacteria by disinfecting water. Their presence in water indicates a treatment failure or lack of treatment. A total coliform count is used to indicate hygiene levels and the possible presence of enteric pathogens in water. Health Canada has developed a technical Guideline for Total Coliforms in which detailed information about analytical methods for testing water, water sampling and water treatment technology can be found.
 
Chemical Contaminants: Chemical contamination of water can occur from chemical spills, incorrect use of pesticides, improper water treatment or improper disposal of industrial waste into waterways. Harmful chemicals in water can cause adverse health effects.  
Examples of toxic chemicals include: 
  • pesticides
  • mineral salts (ex: nitrates, copper, sulfates)
  • heavy metals (ex: arsenic, lead, mercury, cadmium, silver)
  • volatile organic compounds (ex: phenols)
  • asbestos
  • organic chemicals
  • radionuclides (ex: uranium, radium, radon)

Maximum acceptable concentrations for chemical contaminants are established by Health Canada in the Guidelines for Canadian Drinking Quality-Summary Table.

Physical Contaminants: Physical contaminants of water pose a low health risk to consumers but may affect the quality of water. Water may contain suspended particles of fine sand, clay and precipitated salts. This cloudiness is called turbidity and can interfere with effective disinfection and purification of water. Unpleasant taste or odours are likely caused by organic substances, such as: decaying vegetation, algae or organic chemicals containing carbon.
 
For more information on the maximum acceptable level for physical contaminants, see Guidelines for Canadian Drinking Water Quality-Summary Table.

 

Water Safety Analysis  

Food processors must have a system that ensures they are using safe, potable water in food production. In order to ensure safe water, it must be sampled, tested and documented.
 
Water Sampling
 
Water in a food facility should be tested from different outlets at regular intervals.  A minimum of 100 milliliters water sample is required. However 500 milliliter should be collected, in case that more water analyses are required on the same sample. When taking samples, food processors should:   
  • Run water from taps or hoses for at least three minutes before collection in sterile bottles. 
  • Transport water samples promptly to the certified testing laboratory -- no more than 24 hours between sample collection and testing.   
  • Include water sampling procedures (ex: how to sample, how often, where to sample) in a written Standard Operating Procedure (SOP) (PDF 251 KB). 
  • Test water samples for microbial and chemical parameters. 
Water testing helps reveal contamination. A list of laboratories that provide testing services can be found in the Laboratories and Testing.  
 
Microbial testing
 
Microbial analysis should include total coliform counts. Escherichia coli is the most specific indicator of fecal contamination and the possible presence of pathogens. New methods for microbial analysis also include the heterotrophic plate count (HPC), which estimates the number of live heterotrophic bacteria (bacteria requiring carbon for growth) in water. This technique helps identify waterborne bacteria.  
 
Interpreting microbial results: water test results need to be interpreted with caution. Pathogens do not distribute uniformly in water, so a negative result does not guarantee the absence of pathogenic bacteria. Different laboratories have their own ways of expressing the number of organism (coliform or E. coli). 
 
Examples of different lab reports include:
  • absolute number (ex: 250 organisms)
  • cfu/100 milliliters (colony-forming units per 100 milliliters)
  • numbers expressed by E where E means exponent to the power of 10 (ex: 2.5 E+02 converts to 2.5 X 10 X 10 which equals 250 organisms)

The maximum acceptable concentration for both coliforms and E. coli in water used in food production is zero per 100 ml,  under the Guidelines for Canadian Drinking Water Quality

When tests show positive results:

a) Food processors can accept the test result and take immediate corrective action. All products should be detained until laboratory analysis confirms the product is safe.  If a product contaminated with possible pathogenic bacteria has been shipped, a recall of the product may be necessary. Immediately notify the appropriate local regulatory authority or the CFIA. Call 204-229-9896 within Manitoba. 

b) Test the duplicate sample to confirm the results. However, the most practical response is to accept the initial result, rather than trying to prove that it was a false result.

Chemical testing

Water samples for chemical analysis should be collected at least once a year. Chemical test should include:

  • pH
  • heavy metals pesticides
  • residual chlorine
  • water hardness (water within high mineal content)
  • iron
  • nitrates

For a complete list of current guidelines for chemical parameters visit the Guideline for Canadian Drinking Water Quality - Guidelines for chemical and physical parameters section.

Documentation

Keep records of microbial and chemical samples. These records can help monitor results, help processors decide if additional sampling/testing is required and are necessary for auditing. 

 

Water Systems in a Food Facility

  • Keep complete and updated plumbing diagrams of the food plant.  Food processors need to know how fresh water is obtained and ensure that cross-contamination with sewage is avoided.  
  • Water lines should remain clean to ensure there is no risk of potential contamination within the food operation.
  • Back-flow prevention devices can help to keep water clean. They prevent dirt or contaminated water from flowing towards a clean source.
  • The facility’s water systems need to provide water at the required temperature and pressure for food processing, cleaning equipment and employee sanitary facilities within a food plant.

Aspects to consider in a water treatment program include:

  • trained personnel are responsible for the water treatment
  • type of treatment to be performed
  • chemicals/equipment required
  • explicit directions to perform the treatment
  • schedule for water treatment
  • records of the treatment and results obtained

Water Treatment Options
A water treatment system should be selected based on the contaminants to be removed, amount of water to be treated, initial and ongoing costs of operation and maintenance. The treatment selected should purify water to the quality levels required for its intended use.

Some examples of water treatment options are: 

  • chlorination
  • hydrogen peroxide
  • reverse osmosis
  • filtration
  • ultraviolet radiation
  • ozonation
The CFIA has published a Reference Listing of Accepted Construction Materials, Packaging Materials and Non-Food Chemical Products on chemicals that should be used for water treatment.
 

Water for Cleaning and Sanitation 

Water for cleaning is often used to remove visible soil. Cleaning compounds used with water enhance its cleaning ability. Sanitizers are used with water to reduce the population of microorganisms on food contact surfaces.  
 
Water hardness can affect the performance of cleaning chemicals. For instance, it increases detergent consumption which may cause film to form on equipment surfaces. The effectiveness of the sanitizer is also affected by water chemistry. For example, chlorine is more effective at lower pH values, since greater antimicrobial activity can be achieved.    
 

References 

Stier, R. 2006. Assuring Water Quality and Safety in Food Processing. Food Safety Magazine (8-9): 26-29.
McKnight, S. 2002. Issues on Water Quality and Safety.  Dairy, Food and Environment Sanitation (6): 52-53. 
 

Related Links  

Manitoba Water Stewardship
 
Manitoba Health fact sheets on testing and disinfecting well water: 

 

For more information, email the CVO/Food Safety Knowledge Centre or call 204-795-8418 in Winnipeg.