Pool water draining rules in the GTA

Discharge

• Chlorinated pool water may go to the storm sewer only after it has been dechlorinated, and not on a day when rain is forecast.
• The city's storm limits are chlorine 0.01 mg/L, copper 0.04 mg/L and pH 6–9.5.
• Salt water never goes to a storm sewer. It goes to the sanitary connection on your own property, or to an approved hauler.
• Pool water can never be discharged onto ground near a ravine or valley — it erodes the banks and damages vegetation. Backwash must be filtered and dechlorinated before storm discharge, otherwise it goes to the sanitary sewer.

Backflow

Annual backflow testing applies to industrial, commercial, institutional and Part 3 residential buildings. A detached house filling a pool from a hose bib is not part of that program.

City of Toronto — how to drain a pool · City of Toronto — backflow prevention

Discharge

• Peel's Sewer Use By-law 53-2010 treats a residential pool as part of the home and bars sanitary discharge below pH 5.5 or above 10.
• City guidance varies — Mississauga publishes safe-disposal practices that keep chlorinated water out of storm drains — so check your city's page before draining.

Backflow

Peel requires annual testing for commercial, institutional and multi-residential properties, and for single homes larger than 600 m². A cross-connection survey is due within 60 days of the notice, devices within a year, and installation permits come from your city's building department rather than the Region.

Peel Region — Sewer Use By-law 53-2010 · Peel Region — backflow prevention

Discharge

• Peel's Sewer Use By-law 53-2010 treats a residential pool as part of the home and bars sanitary discharge below pH 5.5 or above 10.
• City guidance varies — Mississauga publishes safe-disposal practices that keep chlorinated water out of storm drains — so check your city's page before draining.

Backflow

Peel requires annual testing for commercial, institutional and multi-residential properties, and for single homes larger than 600 m². A cross-connection survey is due within 60 days of the notice, devices within a year, and installation permits come from your city's building department rather than the Region.

Peel Region — Sewer Use By-law 53-2010 · Peel Region — backflow prevention

Discharge

• Peel's Sewer Use By-law 53-2010 treats a residential pool as part of the home and bars sanitary discharge below pH 5.5 or above 10.
• City guidance varies — Mississauga publishes safe-disposal practices that keep chlorinated water out of storm drains — so check your city's page before draining.

Backflow

Peel requires annual testing for commercial, institutional and multi-residential properties, and for single homes larger than 600 m². A cross-connection survey is due within 60 days of the notice, devices within a year, and installation permits come from your city's building department rather than the Region.

Peel Region — Sewer Use By-law 53-2010 · Peel Region — backflow prevention

Discharge

• Vaughan requires pool water to sit above pH 6.0 and below 9.0 before it is drained.
• Stop adding chemicals for two weeks before draining — that is the city's own instruction, not a rule of thumb.
• Salt water and neutralised acid-wash runoff go to the sanitary connection, never a catch basin.
• Discharging behind the property into a ravine, trail or woodlot is not permitted.

Backflow

Markham runs its own backflow program under By-law 2012-27, including contractor registration. The annual test attaches to devices required for the property, not to a hose filling a pool.

Richmond Hill — draining a pool or hot tub · Markham — backflow prevention · City of Vaughan — pool water disposal

Discharge

• York Region's municipalities set their own pool-discharge rules; there is no single regional limit, so the town that issues your address decides.
• Richmond Hill and Vaughan both prohibit discharge onto ground near a ravine, valley or woodlot, and neither allows salt water into a storm catch basin.

Backflow

Markham runs its own backflow program under By-law 2012-27, including contractor registration. The annual test attaches to devices required for the property, not to a hose filling a pool.

Richmond Hill — draining a pool or hot tub · Markham — backflow prevention

Discharge

• Richmond Hill requires dechlorination before storm discharge and warns against draining on a rainy day.
• Salt water cannot enter the storm system. Use the sanitary connection on your property or an MECP-approved hauler.
• The town prohibits discharge onto ground near a ravine or valley. It publishes no numeric pH limit — dechlorination is described in plain terms, so test before you drain.

Backflow

Markham runs its own backflow program under By-law 2012-27, including contractor registration. The annual test attaches to devices required for the property, not to a hose filling a pool.

Richmond Hill — draining a pool or hot tub · Markham — backflow prevention · Richmond Hill — draining a pool or hot tub

Discharge

• Oakville requires pool water to be discharged in the front yard, directed to the street curb and gutter, a municipal ditch, or another outlet the Town approves.
• Discharging to the rear yard, wooded areas, ravines or town trails is not permitted.
• A pool permit needs a grading plan showing the sump pump discharging out front toward the roadway.
• Keep a 1.0 m (3 ft 3 in) strip undisturbed from every property line so existing grades and drainage swales keep working.

Backflow

Halton requires annual testing for industrial, commercial and multi-unit residential properties — two or more dwellings, excluding secondary suites — and names irrigation systems as a moderate hazard needing a DCVA.

City of Burlington — where pool water goes · Halton Region — cross connection control · Town of Oakville — pool permit guidelines

Discharge

• Halton's towns publish their own discharge guidance. Burlington, for example, advises letting water sit about a week, testing chlorine near zero, then releasing it slowly onto the lawn or to a storm sewer on a dry day.
• Salt water must go to the sanitary sewer connection on your property or an approved hauler — never a storm drain, ravine or creek.

Backflow

Halton requires annual testing for industrial, commercial and multi-unit residential properties — two or more dwellings, excluding secondary suites — and names irrigation systems as a moderate hazard needing a DCVA.

City of Burlington — where pool water goes · Halton Region — cross connection control

Discharge

• Halton's towns publish their own discharge guidance. Burlington, for example, advises letting water sit about a week, testing chlorine near zero, then releasing it slowly onto the lawn or to a storm sewer on a dry day.
• Salt water must go to the sanitary sewer connection on your property or an approved hauler — never a storm drain, ravine or creek.

Backflow

Halton requires annual testing for industrial, commercial and multi-unit residential properties — two or more dwellings, excluding secondary suites — and names irrigation systems as a moderate hazard needing a DCVA.

City of Burlington — where pool water goes · Halton Region — cross connection control

Discharge

• Durham's regional sewer by-law sets no pool-specific limits; the conditions sit in area by-laws. Whitby's allows pool water to the storm sewer provided it contains no algaecides.

Backflow

Durham's program covers commercial, institutional and multi-residential services, with the premise-isolation device tested annually. Anything beyond the meter, including a pool-fill connection, is handled by the local building department.

Durham Region — backflow prevention · Durham Region — regional storm sewers

Discharge

• Durham's regional sewer by-law sets no pool-specific limits; the conditions sit in area by-laws. Whitby's allows pool water to the storm sewer provided it contains no algaecides.

Backflow

Durham's program covers commercial, institutional and multi-residential services, with the premise-isolation device tested annually. Anything beyond the meter, including a pool-fill connection, is handled by the local building department.

Durham Region — backflow prevention · Durham Region — regional storm sewers

Discharge

• Durham's regional sewer by-law sets no pool-specific limits; the conditions sit in area by-laws. Whitby's allows pool water to the storm sewer provided it contains no algaecides.

Backflow

Durham's program covers commercial, institutional and multi-residential services, with the premise-isolation device tested annually. Anything beyond the meter, including a pool-fill connection, is handled by the local building department.

Durham Region — backflow prevention · Durham Region — regional storm sewers

Discharge

• Durham's regional sewer by-law sets no pool-specific limits; the conditions sit in area by-laws. Whitby's allows pool water to the storm sewer provided it contains no algaecides.

Backflow

Durham's program covers commercial, institutional and multi-residential services, with the premise-isolation device tested annually. Anything beyond the meter, including a pool-fill connection, is handled by the local building department.

Durham Region — backflow prevention · Durham Region — regional storm sewers