Minimum level of treatment
4. (1) The owner of a water treatment or distribution system shall ensure the following: 1. Any well used as a water source is constructed and maintained to prevent surface water and other foreign materials from entering the well. 2. Water treatment equipment is provided in accordance with this section. 3. The water treatment equipment is in operation whenever water is being obtained or supplied. 4. The water treatment equipment is operated in a manner that achieves the capabilities it is required to have under paragraph 2. 5. The water treatment equipment is properly maintained. 6. Written operating instructions for the water treatment equipment are kept near the equipment. 7. Clearly marked adequate supplies of chemicals or other materials necessary for the operation of the water treatment equipment are kept nearby, separate from other chemicals and materials that are not used for the water treatment or distribution system. 8. Replacement parts are kept nearby for those parts of the water treatment equipment that may be expected to require periodic replacement. 9. Maintenance of and adjustments to the water treatment equipment are carried out only by trained persons. O. Reg. 505/01, s. 4 (1). (2) If a water treatment or distribution system obtains water from a ground water source, the owner of the system shall ensure that disinfection equipment is provided that, (a) in the case of chlorination equipment, (i) is capable of providing a contact time of not less than the minimum contact time set out for the system’s baffling conditions in the Table that follows this subsection, and (ii) is capable of providing a minimum chlorine residual of 0.2 milligrams per litre, measured as free chlorine, at maximum flow in all water that has been treated by the equipment; or (b) in the case of other disinfection equipment, (i) is capable of being equivalent to or better than chlorination with respect to the ability to achieve at least 99 per cent inactivation of viruses in water that has a temperature of approximately 10°C and a pH of between 6 and 9, and (ii) is capable of being equivalent to or better than chlorination, having regard to reliability, ease of use and minimization of the formation of disinfection by-products. TABLE GROUND WATER SOURCE — CHLORINATION — MINIMUM CONTACT TIMES (subclause 4 (2) (a) (i))  Item

Baffling Conditions

Minimum Contact Time (minutes)


1.

Unbaffled (mixed flow) separate inlet-outlet: none, agitated basin, very low length to width ratio, high inlet and outlet flow velocities

150


2.

Poor: single or multiple unbaffled inlets and outlets, no intra-basin baffles

50


3.

Average: baffled inlet or outlet with some intra-basin baffles

30


4.

Superior: perforated inlet baffle, serpentine or perforated intra-basin baffles, outlet weir or perforated launders

22


5.

Perfect (plug flow): very high length to width ratio (pipeline flow)

15 O. Reg. 505/01, s. 4 (2). (3) If a water treatment or distribution system obtains water from a surface water source, the owner of the system shall ensure that, (a) filtration and disinfection equipment is provided that is capable of satisfying the requirements of clause 2.2 a and section 3 of the procedure entitled “Chlorination of Potable Water Supplies in Ontario” in the Ministry of the Environment publication entitled “Ontario Drinking Water Standards”, originally dated August 2000, as amended from time to time; or (b) filtration and disinfection equipment is provided that, (i) is capable of being equivalent to or better than filtration and chlorination with respect to the ability to achieve at least 99.99 per cent removal or inactivation of viruses in water of every temperature and pH that is likely to be encountered in the surface water source when the water treatment or distribution system is in operation, (ii) is capable of being equivalent to or better than filtration and chlorination with respect to the ability to achieve at least 99.9 per cent removal or inactivation of giardia lamblia cysts in water of every temperature and pH that is likely to be encountered in the surface water source when the water treatment or distribution system is in operation, and (iii) is capable of being equivalent to or better than filtration and chlorination, having regard to reliability, ease of use and minimization of the formation of disinfection by-products. O. Reg. 505/01, s. 4 (3). (4) Subsection (3) applies, and subsection (2) does not apply, to a water treatment or distribution system that obtains water from, (a) a well, any part of which is within 15 metres of surface water; or (b) an infiltration gallery. O. Reg. 505/01, s. 4 (4). (5) Subsection (3) does not apply to the extent that an approval granted on or after December 19, 2001 imposes different requirements and provides that they apply instead of requirements that would otherwise be imposed by subsection (3). O. Reg. 505/01, s. 4 (5). (6) If a water treatment or distribution system includes a water distribution system or provides water to plumbing, and any part of the water distribution system or plumbing is in the natural environment, the owner of the water treatment or distribution system shall, in addition to complying with subsection (2) or (3), whichever is applicable, ensure that disinfection equipment is provided that, (a) in the case of chlorination equipment, (i) is capable of providing disinfection that persists into the water distribution system or plumbing, and (ii) is capable of providing a free chlorine residual of at least 0.2 milligrams per litre at every point in the water distribution system or plumbing; or (b) in the case of other disinfection equipment, (i) is capable of being equivalent to or better than chlorination with respect to the ability to achieve disinfection that persists into the water distribution system or plumbing and the ability to ensure disinfection at every point in the water distribution system or plumbing, and (ii) is capable of being equivalent to or better than chlorination, having regard to reliability, ease of use and minimization of the formation of disinfection by-products. O. Reg. 505/01, s. 4 (6). (7) Subsection (6) does not apply if the owner complies with subsection (2) or (3), whichever is applicable, and all disinfection provided in accordance with subsection (2) or (3) takes place at a point or points in the water treatment or distribution system that is after all parts of the water distribution system or plumbing that are in the natural environment. O. Reg. 505/01, s. 4 (7). (8) This section prevails over an approval granted before December 19, 2001 that provides for less stringent requirements. O. Reg. 505/01, s. 4 (8). (9) If a water treatment or distribution system commenced operation before December 19, 2001 and, immediately before that day, was not in compliance with this section, the owner of the system is not required to comply with this section until, (a) September 1, 2002, if the water treatment or distribution system serves a school; or (b) December 31, 2002, if the water treatment or distribution system does not serve a school. O. Reg. 505/01, s. 4 (9).