Guidance For Providing Safe Drinking Water in Areas of Federal Jurisdiction - Version 1

Part 2 - Application of The Federal Framework

The multi-barrier approach incorporates the principle of sound quality management. A significant part of the federal government's commitment to ensuring the safety and reliability of drinking water supplies lies in its commitment to properly design treatment programs, facilities, and distribution systems that are run by appropriately trained staff to perform consistently and reliably.

A comprehensive review and approval process for new or upgraded water systems is essential to ensure all project proposals are reviewed and commented on at their various stages of development and to ensure that relevant standards and requirements are met. An effective and coordinated review and evaluation of project proposals will result in the overall reduction of potential health hazards in the new or upgraded water system.

3.0 Surveys, Assessments and Monitoring

The monitoring program for all federal drinking water systems should be developed based on a sanitary survey in combination with a vulnerabilities assessment and a baseline chemical analysis. Each of these steps should be conducted by a competent expert in the appropriate field.

Thereafter, a sanitary survey, vulnerabilities assessment and baseline chemical analysis should be conducted every 5 years, or when there are significant changes to the treatment system, land use, or other conditions which may adversely affect water quality. This will help to determine if changes are required to the monitoring program.

It is recognized that, in the case of unique facilities or situations such as systems in remote locations that serve very few individuals, it may not be physically or economically feasible to conduct each of the survey/assessment/analysis components every 5 years once the initial ones have been done. In these cases, every effort should be made to, at a minimum, do the sanitary survey and vulnerabilities assessment every 5 years, to determine if any changes have occurred that might require changes to the ongoing monitoring program.

Although the survey/assessment/analysis may only be done every five years, departments should endeavour to be aware on an ongoing basis of any changes at a site that could impact on water quality.

These steps apply for all systems, new or existing. However, case-specific guidance for a number of scenarios, including groundwater supplies and municipally- owned systems, is provided in Section 3.5. New systems will also need to undergo the steps outlined in Section 3.1.

3.1 Choosing a source for drinking water

The first step in assessing the drinking water supply is to assess the quality and quantity of the source water. This would include sampling and analysis of the raw water quality at the intake, as well as assessment of seasonal variations as applicable.

The goal of this step is to determine whether:

• The source water is of high enough quality that it can be rendered safe for human consumption.
• The quantity of water available is suitable for the number of people who will be using it over the long term, the types and duration of activities they will use it for, and water demands for other uses (e.g., industrial or recreational).

In addition, the results of the source water assessment help determine the extent of treatment or other management actions required.

When selecting a source for drinking water, where feasible, more than one water source should be evaluated. Doing so will help determine whether a better source exists or if an alternative source is available that can be used as a back-up in cases where the chosen water supply becomes contaminated or otherwise unsuitable.

As part of the overall assessment, an evaluation of demands on water quantity is also required.

Once the source water has been identified, a vulnerabilities assessment needs to be completed.

3.2 Vulnerabilities assessment

The vulnerabilities assessment is a comprehensive assessment of the vulnerability of the source water in the environment. It includes three elements:

• Delineation of watersheds, aquifers and their protection areas
• Identification of hazards, including contaminants of concern and their sources (where possible to determine)
• Assessment of susceptibility to contamination, and ranking of the hazards.

3.2.1 Delineation of watersheds and aquifers

The land area that contributes water and potential contaminants to the water supply must be defined and mapped (delineated) in order for drinking water managers to focus their efforts within a defined area and respond appropriately to incidents or emergencies.

This component of the vulnerabilities assessment should include characterizing the water source, geology, and features of the surrounding area to determine what may be in the water and what could become a concern in the treated drinking water (e.g., bromide in humic acid in the source water could react with chlorine or other chlorinated disinfectants to form brominated disinfection by-products at the tap).

Many methods exist to delineate watersheds and aquifers, ranging from simplistic terrain mapping to complex mathematical models requiring significant amounts of field data. The decision about which method is required will depend on source water characteristics and the relative risk of contamination.

3.2.2 Identifying source water hazards

The next step is to identify the potential hazards to the water source within the delineated area. Hazards can be identified in a number of ways such as inventories of land uses and contaminant sources, evaluations of watershed and/or aquifer characteristics, and monitoring data related to source water quality and quantity.

The level of effort expended on identifying hazards will depend on available resources. However, the goal should be to collect as much data as feasible on contaminants (including their sources and concentrations), pressures on water quantity, and to fill knowledge gaps with new information from public consultations and/or field studies.

In the vulnerabilities assessment, it is essential to identify hazards, as they influence the type of treatment required as well as any response required in the watershed/aquifer. For instance, a watershed where the primary hazards come from industrial effluent will be managed differently than one where the main threat to water quality is nutrient enrichment.

3.2.3 Susceptibility to contamination

Once the hazards have been identified within a delineated area, the vulnerability of the source to the hazards needs to be determined. The potential impact of the hazards on human health also needs to be determined. The results of these assessments influence the treatment required to ensure the water is safe and aesthetically-pleasing for human consumption. They also guide integrated watershed/aquifer protection efforts by identifying the quantity and quality of the water and its potential vulnerability to degradation. Assessment results may be extremely useful to other agencies and stakeholders who share common interests.

In assessing vulnerability or risk, the data from the identification of hazards needs to be complemented with monitoring data to get an idea of the concentration at which the contaminant is found in the source water and whether this concentration fluctuates over time. Fluctuations in physical parameters should also be noted. These types of data are gathered through long-term monitoring programs. While concentrations can be modelled, it is preferable to obtain real-time, site-specific monitoring data.

3.3 Sanitary survey

A sanitary survey is an on-site review, from intake to tap, of a water utility's raw water quality, facilities, equipment, operations, and maintenance records for the purpose of evaluating the utility's ability to adequately treat source water in order to produce and deliver safe drinking water. The sanitary survey will vary depending upon the type and complexity of the system.

Variations in the quality of water supplies can help in detecting contamination problems, and in determining whether they have arisen at the source, during water treatment, or in the distribution system. However, it may often not be possible to take more than a few samples, and consequently the results of any analysis may not be representative of the water-supply system as a whole. ⁽⁵⁶⁾

Sanitary surveys, while they cannot replace water-quality analyses, are an essential complement to such analyses as part of water-quality control programmes. They allow for an overall appraisal of the many factors associated with a water-supply system, including the waterworks and the distribution system. ⁽⁵⁶⁾

Sanitary surveys are intended to provide a range of information and to locate potential problems. The data obtained may identify failures, anomalies, operator errors, and any deviations from normal that may affect the production and distribution of safe drinking-water. ⁽⁵⁶⁾

3.4 Baseline chemical analysis

A baseline chemical analysis is an analysis of all Guidelines for Canadian Drinking Water Quality for chemical parameters (including initial screening for radiological parameters) with Maximum Acceptable Concentrations (MACs). As part of this analysis, departments may choose to look at aesthetic parameters and operational guidance values as well.

The baseline chemical analysis, in combination with the sanitary survey and vulnerabilities assessment, should result in the monitoring program, i.e. a list of substances that should be routinely monitored. Based on the list, departments should be able to develop an appropriate treatment regime.

It is recommended that monitoring programs for identified chemical contaminants include, at a minimum, annual monitoring for surface water sources, and monitoring every 2 years for groundwater sources, unless otherwise specified in the Guidelines for Canadian Drinking Water Quality.

As a safeguard, it is also recommended that a baseline chemical analysis be re-conducted every five years, unless a sanitary survey or vulnerabilities assessment indicates that this type of analysis should be done more or less frequently.

If particular substances are consistently absent from a water system, the frequency of sampling of those substances can be reduced. As well, where water supplies are obtained from sources that are not likely to be contaminated by industrial and agricultural wastes, a baseline chemical analysis may be needed only to help select new drinking water sources and then only occasionally thereafter. ⁽¹⁵⁾

For drinking water supplied by a municipality, the baseline chemical analysis would include an analysis of the water received to determine if there are any concerns with the supply that require further treatment or whether an alternative source should be used. Federal departments and First Nations communities should request water quality testing results from the municipality. This information will indicate which substances are being tested for and analysed.

See Appendix 2: Summary of Guidelines for Canadian Drinking Water Quality for the detailed listing of chemical contaminants for which drinking water quality guidelines have been developed.

3.5 Case-specific guidance

3.5.1 Groundwater supplies

The risks associated with groundwater contamination vary with the type of activities on the property and the surrounding land use, the soil type, as well as the type and condition of the wellhead or wellfield.

A vulnerabilities assessment report for all existing groundwater systems should include a description of the facility and surrounding land use, the direction and rate of groundwater flow, capacities of the selected water source, radius of influence, hazards associated with the water source, and protection measures that are either in place or needed.

The sanitary survey for groundwater should also include a review of previous sampling results, identify whether further treatment is required, investigate the type of well in place (or proposed), and lay out requirements for well head protection. It should recommend improvements and upgrades where needed, and identify any compliance and enforcement issues. Federal staff and, in First Nations communities, managers and/or operators of facilities and the water treatment plant operator, will then be able to regularly update well records.^{(5, 21)}

The amount of effort and resources expended on assessing the groundwater supply will depend on factors such as its size, use, and location.

A sample Well Assessment Form is provided in Appendix 3.

Suitable sealing, capping, filling or removal of wells to be abandoned is important to ensure the safety of the aquifer and the environment and to protect against future hazards. (Inclusion of relevant guidelines for abandoning wells is beyond the scope of this document.)

3.5.2 Municipally-owned systems

Often the source of potable water for facilities owned and operated by the federal government is the local municipality. The quality of this water is the responsibility of the system owner.

In order to ensure the water received is of acceptable quality, federal water quality managers and, in the case of First Nations communities, water treatment plant operators and technical support staff, should be in regular contact with the municipality.

Maintaining solid relationships with key contacts in the municipality's drinking water program is important in order to be kept informed of any water quality or quantity issues that could affect the health of consumers.

Staff should periodically review the municipality's reports describing water sampling results in order to keep informed of the water's changing characteristics and to understand the quality of drinking water entering the facility's distribution system or building plumbing.

3.5.2.1 Federal buildings with municipally supplied drinking water

The sanitary survey and vulnerabilities assessment for federal buildings needs to verify the condition of the plumbing, the type of materials, and the state of the connections, including cross-connections, within the building. The sanitary survey should be done every five years. However, federal departments could use the vulnerabilities assessment to support their decision to do sanitary surveys on a less frequent basis. Alternatively, depending on the results of the assessment, some parameters may be subject to annual, or more frequent, testing.

In cases where water is received from a municipality, it may be possible to negotiate to have the federal building designated as a routine municipal water sampling location. If this is not possible, water samples should be collected at the point closest to the intake of municipal water to the building in order to establish a baseline understanding of the water quality.

Additional samples taken from points within the building will indicate whether water quality is deteriorating within the building.

3.5.3 Staff quarters

For unique facilities and situations (such as where departments provide staff housing in remote locations), each department must establish their own monitoring programs based on the sanitary survey, vulnerabilities assessment and baseline chemical analysis.

For these unique facilities/situations, departments may choose to stagger the monitoring programs over a five year period for each individual staff quarters, but at least 5% should be completed in any given year. All staff quarters must be covered in the 5 year period, unless the sanitary survey and vulnerabilities assessment indicates a different frequency would be appropriate.