Ontario Drinking Water Systems Regulation

(O. Reg. 170/03)

The new Ontario Regulation 170/03 (O. Reg. 170/03) was made under the Safe Drinking Water Act, 2002 and came into force on June 1st, 2003 . This regulation prescribes strict and mandatory requirements that are the toughest in Canada.

O. Reg. 170/03 (and related regulations) revokes O. reg. 459/00 and O. Reg. 505/01 and is based on the new Safe Drinking Water Act, 2002.  O. Reg. 170/03 addresses eight categories of drinking water systems. This now includes water treatment systems that supply water at less than 2.9 L/s (or less than 250,000 L/day). Table 1 summarizes the definitions for each of the eight different categories of drinking water systems.

Table 1: Definition of the Eight Drinking-Water System Categories

Category of Drinking Water System

Definition

Large Municipal Residential System

A municipal drinking water system that serves a major residential development and serves more than 100 private residences.

Small Municipal Residential System

A municipal drinking water system that serves a major residential development but serves fewer than 101 private residences

Large Municipal Non-Residential System

A municipal drinking water system that does not serve a major residential development and is capable of supplying drinking water at a rate of more than 2.9 litres per second (L/s)

Small Municipal Non-Residential System

A municipal drinking water system that does not serve a major residential development, is not capable of supplying drinking water at a rate of more than 2.9 L/s and serves a designated facility or a public facility.

Non-Municipal Year-Round Residential System

A non-municipal drinking water system that is not a seasonal system and serves a major residential development or a trailer park or campground that has more than five service connections.

Non-Municipal Seasonal Residential System

A non-municipal drinking water system that is a seasonal system and serves a major residential development or a trailer park or campground that has more than five service connections.

Large Non-Municipal Non-Residential System

A non-municipal drinking water system that is capable of supplying drinking water at a rate of more than 2.9 L/s and does not serve a major residential development or a trailer park or campground that has more than five service connections. 

Small Non-Municipal Non-Residential System

A non-municipal drinking water system that is not capable of supplying drinking water at a rate of more than 2.9 L/s, serves a designated facility or public facility and does not serve a major residential development or a trailer park or campground that has more than five service connections.

Drinking water systems require a Professional Engineer to prepare an evaluation report and certify that the water system is in compliance with the regulatory requirements and must be operated by certified operators. The minimum treatment requirements are:

  1. Chlorination for ground water sources not under the influence of surface water, and
  2. Filtration and Chlorination for surface water sources and ground water sources under the direct influence of surface water.

The deadlines for meeting the minimum treatment requirements, along with the Engineering Evaluation Report and Owner’s Notice to the MOE Director for each of the eight categories are listed in O. Reg. 170/03. Please note that the Engineering Evaluation Report and the Engineer’s Certification Letter are required every 5 years for a surface water or groundwater under the direct influence of surface water and every 10 years for a groundwater site not under the direct influence of surface water.

The requirement for an Engineering Evaluation Report does not apply if the drinking water system received an OWRA Section 52 Certificate of Approval after Aug 1, 2000 . All that is required is a certification letter from a professional engineer indicating that he/she has visited the site and that the system complies with the existing approval. The assumption is that the engineering report for the existing approval has already been prepared.

There is no relief from minimum treatment requirements for surface water and groundwater under the direct influence of surface water. For groundwater sources not under the direct influence of surface water there is potential for relief if it can be shown that there is no risk to the public and that the water is safe. Relief would also require the development of a risk analysis and management plan.

Finally, the following are related Regulations:

O. Reg. 169/03: Ontario Drinking Water Quality Standards

O. Reg. 170/03: Drinking-Water Systems

O. Reg. 171/03: Definitions of Words and Expressions used in the Act (Safe Drinking Water Act, 2002)

O. Reg. 172/03: Definitions of “Deficiency” and “Municipal Drinking Water System”

O. Reg. 173/03: Schools, Private Schools and Day Nurseries

O. Reg. 174/03: Amends Ontario Regulation 525/98

O. Reg. 175/03: Revokes Ontario Regulation 459/00

O. Reg. 176/03: Revokes Ontario Regulation 505/01

O. Reg. 177/03: Amends Ontario Regulation 435/93

For more information on how Altech can assist please contact Henri van Rensburg by email or phone at 1-800-323-4937 Ext. 230.