Small drinking water systems and private wells

The definition and regulatory oversight of small drinking water systems (SDWS) across Canada varies by provincial and federal jurisdictions. A small system may be defined by size, or by who owns and operates the system (e.g., municipal or private), or by the type of population it serves (e.g., public, seasonal, residential). Most small systems serve less than 500 people, and many have fewer than 15 connections and are non-municipal supplies. Some non-municipal supplies and private wells may be referred to as private water systems (PWS). Many SDWS or PWS source their water from wells, accessing groundwater from confined aquifers, or groundwater under the direct influence of surface water (GUDI). Some small systems, however, may also use a surface water source, especially in the Canadian Arctic.

In 2019, the majority of boil water advisories in Canada (82%) were for SDWS serving 500 people or less. Many of these systems are in rural and remote locations and small communities where there are operational, technical, and financial challenges that reduce the ability to identify and remedy water quality issues quickly. Users of SDWS and PWS may thus be at higher risk of exposure to contaminants. Water quality can be compromised if source water becomes contaminated by diffuse or point source pollution, if there is damage or direct contamination of wells, or if there is inadequate treatment or failure to maintain quality in distribution or storage systems. The resources listed here are intended to assist environmental and public health professionals and those responsible for managing SDWS and PWS to:

• Understand the factors influencing the safety of drinking water in small systems including key water quality parameters;
• Identify the approaches to assessing and reducing health risks from drinking water in small systems;
• Identify the steps needed to respond to emergencies and how to mitigate adverse impacts;
• Understand some of the challenges facing small systems in First Nations’ communities.

Drinking water quality in small systems

These resources aim to improve understanding of the parameters that are used to assess quality of drinking water in SDWS and PWS, the current state of quality in these systems, and the most common sources of contamination.

• Overview of water-related diseases and contaminants in private wells (US CDC, 2021)
  This website provides an overview of the types of chemical and microbiological contaminants that may be present in well water and links to more information on each.
   
• Drinking water advisories (Health Canada, 2020)
  This webpage provides an overview of the number and primary cause of drinking water advisories across Canada from 2010-2019, and the size of communities affected.
   
• Guidelines for Canadian drinking water quality - summary table (Health Canada, 2020)
  This webpage provides a summary of the guidelines for Canadian drinking water based on current evidence on health, aesthetic, and operational impacts of water contaminants.
   
• Drinking water interpretation tool (Nova Scotia Environment, n.d.)
  This interactive tool allows users to enter water test results and compare these against Canadian drinking water quality guidelines, and links to further information through The Drop on Water Fact Sheet series.
   
• Drinking water guidelines and governance (NCCEH, 2020)
  This NCCEH topic page provides an overview of guidelines and governance of drinking water at the federal, provincial and territorial levels in Canada.
   
• Private wells and rural health: groundwater contaminants of emerging concern (Lee et al., 2020)
  This review article presents an overview of contaminants of public health concern in well water in rural North America including microbiological contaminants, nitrates, metals, and emerging organic contaminants.
   
• Chemical and microbial characteristics of municipal drinking water supply systems in the Canadian Arctic. (Daley et al., 2017)
  This article provides an overview of drinking water quality in communities in Nunavut served by SDWS, and identifies some key challenges faced in rural and remote communities.
   
• A systematic review of waterborne disease outbreaks associated with small non-community drinking water systems in Canada and the United States. (Pons et al., 2015)
  This systematic review reports on the primary causes of waterborne outbreaks in SDWS and identifies seasonal trends. See S1 for definitions of small systems used in Canadian provinces

Managing small drinking water systems

The following resources focus on operational aspects of SDWS, approaches used to assess risks, including sampling and testing, and consideration of governance structures in achieving good water quality in SDWS and PWS.

• Public health guidelines for non-municipal drinking water (Alberta Health Services, 2021)
  This guidance document provides an overview of best practices for managing non-municipal water systems to ensure protection of source water, safe transport and storage of drinking water, treatment approaches and monitoring and maintenance.
   
• Directory of laboratories (Canadian Association for Laboratory Accreditation Inc., 2021)
  This directory provides a listing of laboratories accredited by CALA to perform testing of water and other sample matrices, searchable by the chemical or microbiological parameter of interest.
   
• Small drinking water systems research (US EPA, 2020)
  This website summarizes new research for SDWS in the areas of emerging contaminants, treatment and disinfection technologies, and tools such as the Drinking Water Treatability Database.
   
• Small drinking water systems risk assessment guideline (Ontario Ministry of Health and Long-Term Care, 2018).
  This guidance document, provides advice to public health inspectors on risk assessment of SDWS, and recommended actions for owners and operators, from water testing to treatment and training.
   
• Small drinking water systems operator’s guide (CIPHI Ontario, 2018)
  This guidance document provides an overview of the roles and responsibilities of public health units and owners and/or operators of SDWS in Ontario.
   
• Small water system guidebook (BC Ministry of Health, Health Protection Branch, 2017)
  This guidance document provides information for owners and operators of SDWS on understanding the makeup of a SDWS, their responsibilities and how to assess and minimize health risks.
   
• The development of a sustainable operation model for small non-community drinking water systems in Ontario, Canada. (Sekercioglu et al., 2019)
  This article examines management strategies and barriers to providing safe drinking water in SDWS, and alternative operational models based on a multi-barrier approach.
   
• Small systems, big challenges: review of small drinking water system governance (McFarlane and Harris, 2018)
  This review identifies challenges to improving drinking water quality in SDWS, with a focus beyond technical and operational challenges to governance issues of key importance.

Responding to emergencies

Flooding, wildfires, or other unplanned events can have an adverse impact on source water, treatment systems, stored water, and distribution systems. These resources aim to improve understanding of potential risks to SDWS and PWS from such events, and the actions to restore safe water supplies.

• Be Well Aware - Information for private well owners (Health Canada, 2019)
  This webpage provides guidance on measures PWS owners can take to protect well water from pathogens and chemicals, and ensure well water is safe during and after emergencies.
   
• Well disinfection tool (Public Health Ontario, 2019)
  This webpage explains precautions and procedures for well disinfection. (Similar resources are available from health authorities across Canada (e.g., Disinfecting your well (Northern Health, 2014); Disinfecting drinking water (HealthLink BC, 2021), and consideration should also be given to disinfection of Water storage tanks (Government of Manitoba, 2014)).
   
• Returning to your home after wildfires (First Nations Health Authority, n.d.)
  This fact sheet provides a collection of health and safety considerations for returning home after a wildfire including measures to ensure safe drinking water for residents on a SDWS or private well.
   
• Finding safe water in an emergency(NCCEH, 2019)
  This NCCEH video helps residents understand their likely water needs in an emergency and how to source or collect water around their homes in a safe manner.
   
• Emergency response and contingency planning for small water systems (BC Government, 2016)
  This guidance document, designed for operators of SDWS (up to 500 persons), sets out the approach to developing an emergency response and contingency plan for drinking water impacted by unexpected events (natural, technological, or human-caused).
   
• Guidance for issuing and rescinding boil water advisories in Canadian drinking water supplies. (Health Canada, 2015)
  This guidance document summarizes the factors to consider before issuing or rescinding boil water advisories, and provides guidance to both decision makers and those impacted by advisories.

Small systems in First Nations communities

First Nations communities with SDWS are more likely to experience water quality challenges than other communities across Canada. The resources below identify some of the key challenges and approaches used to address poor water quality in these communities.

• Protecting water during uncertain times (Assembly of First Nations, 2021)
  These symposium proceedings (AFN 4^th annual water symposium) cover current topic areas of importance to First Nations health including water quality, drinking water advisories, technology, sustainability, watershed management, and water governance.
   
• Water in First Nations communities (Indigenous Services Canada, 2021)
  This webpage sets out information on drinking water in First Nations communities across Canada including information on short-term and long-term drinking water advisories, protocols and guidelines, and roles and responsibilities.
   
• Ending long-term drinking water advisories (Indigenous Services Canada, 2021)
  This webpage provides a description of long-term drinking water advisories on public systems on reserve and progress on lifting advisories, along with a map of affected sites south of 60° N latitude.
   
• In pursuit of water health equity for indigenous and rural communities (RES’EAU, n.d.)
  This report summarizes the approach used by RES’EAU-WaterNET to assist small, rural and indigenous communities to achieve sustainable drinking water solutions, with case studies highlighting the types of challenges faced and approaches used to address them.
   
• Water quality and health in northern Canada: stored drinking water and acute gastrointestinal illness in Labrador Inuit. (Write et al., 2017)
  This article reports on a study conducted in an Inuit community, to understand water use and storage practices, and the public health risks from contamination between source and point of use.
   
• Drinking water quality in indigenous communities in Canada and health outcomes: a scoping review. (Bradford et al. 2016).
  This article presents a scoping review examining challenges related to drinking water and health in indigenous communities in Canada and provides recommendations for improving health outcomes associated with poor drinking water quality.
   
• Attawapiskat First Nation FYNE membrane pilot system study. (Attawapiskat First Nation, 2015)
  This case study provides an overview of a pilot project to improve drinking water quality in a remote First Nations community, and highlights lessons learned including consideration of seasonal variability of raw water sources.

This list is not intended to be exhaustive. Omission of a resource does not preclude it from having value.