In order to protect the wastewater treatment plant’s ability to continue treating wastewater during an extreme rainstorm, some of the excess flow (stormwater and sewage) that reaches the plant may need to be diverted around one of the plant’s many treatment processes.
Because the bypass process happens during storm events, the water is mostly rain water (often a ratio of four or five parts rain to one part sewage). All bypass flow continues to goes through:
Bypassses can occur at the Ashbridges Bay and Humber Wastewater Treatment Plants, as these plants service older areas of the city with combined sewers (one pipe that carries stormwater and sewage).
The bypass reports are updated monthly, within 30 days of the end of each month.
| Date | Duration (hrs) | Volume (m3) | Reason |
| January 4 | 5.3416 | 267,090 | Excessive stormwater flow |
| February 9 – 10 | 14.5566 | 745,270 | Excessive stormwater flow |
| March 25 | 8.95 | 427,060 | Excessive stormwater flow |
| April 1 | 6.866 | 351,060 | Excessive stormwater flow |
| April 5 | 9.575 | 453,980 | Excessive stormwater flow |
| April 22 | 8.85 | 248,820 | Excessive stormwater flow |
| May 20 | 6.6833 | 208,350 | Excessive stormwater flow |
| June 12 | 12.6 | 758,740 | Excessive stormwater flow |
| July 13 | 5.516 | 183,610 | Excessive stormwater flow |
| July 27 | 3.092 | 128,310 | Excessive stormwater flow |
| July 29 | 3.325 | 105,660 | Excessive stormwater flow |
| August 25 | 1.4833 | 35,740 | Excessive stormwater flow |
| Date | Duration (hrs) | Volume (m3) | Reason |
| January 4 | 6.0 | 72,890 | Excessive stormwater flow |
| February 17 | 13.4 | 65,174 | Excessive stormwater flow |
| March 17 | 11.1 | 67,795 | Excessive stormwater flow |
| March 25 | 11.7 | 112,948 | Excessive stormwater flow |
| April 1 | 11.1 | 41,006 | Excessive stormwater flow |
| April 05 | 12.4 | 101,625 | Excessive stormwater flow |
| April 22 | 2.6 | 12,894 | Excessive stormwater flow |
| April 30 | 4.8 | 28,012 | Excessive stormwater flow |
| Date | Duration (hrs) | Volume (m3) | Reason |
| February 2 | 2.9166 | 50,140 | Excessive stormwater flow |
| February 17 | 12.7666 | 591,830 | Excessive stormwater flow |
| February 22 | 3.6166 | 111,810 | Excessive stormwater flow |
| June 7 | 7.6333 | 291,650 | Excessive stormwater flow |
| July 18 | 5.1666 | 208,520 | Excessive stormwater flow |
| August 22 | 7.2 | 199,610 | Excessive stormwater flow |
| October 13 | 1.42 | 27,660 | Excessive stormwater flow |
| November 8 | 1.683 | 41 | Annual planned maintenance |
| November 11 | 4.133 | 52,150 | Excessive stormwater flow |
| November 30 | 7.649 | 220,430 | Excessive stormwater flow |
| December 15-16 | 22.2666 | 636,910 | Excessive stormwater flow |
| December 23 | 8.4964 | 232,650 | Excessive stormwater flow |
| December 31 | 9.2333 | 235,370 | Excessive stormwater flow |
| Date | Duration (hrs) | Volume (m3) | Reason |
| February 17 | 15.183 | 191,452 | Excessive stormwater flow |
| February 22 | 4.033 | 12,433 | Excessive stormwater flow |
| March 23 | 3.25 | 35,586 | Excessive stormwater flow |
| July 24 | 0.65 | 4,127 | Excessive stormwater flow |
| December 31 | 1.1 | 1,153 | Excessive stormwater flow |
| Date | Duration (hrs) | Volume (m3) | Reason |
| March 26 | 6.7433 | 305,870 | Excessive stormwater flow |
| June 29 | 0.43 | 6,800 | Excessive stormwater flow |
| July 8 | 3.82 | 216,480 | Excessive stormwater flow |
| August 24 | 2.26 | 31 | Annual planned maintenance |
| September 8 | 3.5 | 153,320 | Excessive stormwater flow |
| September 22-23 | 7.56 | 245,240 | Excessive stormwater flow |
| October 30 | 5.59 | 224,660 | Excessive stormwater flow |
| December 5 | 3.4833 | 122,220 | Excessive stormwater flow |
| Date | Duration (hrs) | Volume (m3) | Reason |
| March 26 | 3.0 | 31,663 | Excessive stormwater flow |
| May 2 | 0.33 | 1,390 | Power/Equipment Failure |
| June 29 | 2.3 | 27,465 | Excessive stormwater flow |
| July 8 | 3.75 | 26,563 | Excessive stormwater flow |
| August 28 | 1.5 | 7,058 | Excessive stormwater flow |
| September 7 | 2.5 | 6,750 | Excessive stormwater flow |
| September 8 | 2.9 | 36,141 | Excessive stormwater flow |
| September 15 | 1.8 | 13,060 | Excessive stormwater flow |
| September 22 | 0.8 | 579 | Excessive stormwater flow |
| September 22 | 7.0 | 128,486 | Excessive stormwater flow |
| October 15 | 1.7 | 15,870 | Excessive stormwater flow |
| December 5 | 3.0 | 34,811 | Excessive stormwater flow |
| December 11 | 2.8 | 17,547 | Excessive stormwater flow |
| Date | Duration (hrs) | Volume (m3) | Reason |
| January 11-12 | 21.55 | 807,000 | Excessive stormwater flow |
| January 24-25 | 23.35 | 1,088,140 | Excessive stormwater flow |
| March 3 | 4.37 | 158,890 | Excessive stormwater flow |
| August 2 | 2.38 | 86,500 | Excessive stormwater flow |
| November 30 | 9.217 | 289,550 | Excessive stormwater flow |
| December 12 | 2.8 | 86,510 | Excessive stormwater flow |
| Date | Duration (hrs) | Volume (m3) | Reason |
| January 11 | 35.8 | 818,105 | Excessive stormwater flow |
| January 24 | 9.6 | 138,795 | Excessive stormwater flow |
| March 3 | 1.5 | 29,099 | Excessive stormwater flow |
| July 8 | 2.7 | 28,667 | Excessive stormwater flow |
| July 11 | 1.0 | 4,664 | Excessive stormwater flow |
| August 2 | 1.9 | 14,440 | Excessive stormwater flow |
| August 3 | 2.1 | 29,135 | Excessive stormwater flow |
| Date | Duration (hrs) | Volume (m3) | Reason |
| February 4-5 | 7.5 | 165,840 | Excessive stormwater flow |
| February 24 | 5.3 | 50,843 | Excessive stormwater flow |
| March 10 | 7.8 | 96,750 | Excessive stormwater flow |
| March 14-15 | 2.6 | 40,120 | Excessive stormwater flow |
| April 14-15 | 3.9 | 215,650 | Excessive stormwater flow |
| April 19 | 3.0 | 58,330 | Excessive stormwater flow |
| April 26 | 5.2 | 255,330 | Excessive stormwater flow |
| May 25 | 2.9 | 54,980 | Excessive stormwater flow |
| June 13 | 7.8 | 163,010 | Excessive stormwater flow |
| June 20-21 | 5.3 | 189,830 | Excessive stormwater flow |
| June 25 | 2.4 | 70,860 | Excessive stormwater flow |
| June 29 | 2.3 | 99,220 | Excessive stormwater flow |
| July 13 | 2.3 | 94,020 | Excessive stormwater flow |
| July 17 | 10.2 | 342,850 | Excessive stormwater flow |
| July 30 | 5.1 | 219,230 | Excessive stormwater flow |
| August 17 | 3.2 | 51,300 | Excessive stormwater flow |
| August 27 | 0.41 | 23,160 | Excessive stormwater flow |
| October 21 | 6.01 | 221,400 | Excessive stormwater flow |
| October 27 | 9.05 | 342,380 | Excessive stormwater flow |
| October 30-November 1 | 16.75 | 592,510 | Excessive stormwater flow |
| December 9 | 7.15 | 256,720 | Excessive stormwater flow |
| December 14 | 10 | 526,270 | Excessive stormwaterflow |
|
Date |
Duration (hrs) | Volume (m3) | Reason |
| February 4-5 | 2.0 | 2,599 | Excessive stormwater flow |
| March 14-15 | 7.2 | 24,383 | Excessive stormwater flow |
| March 30 | 9.4 (5.4 Active)* | 16,555 | Excessive stormwater flow |
| March 31 | 0.8 | 1,727 | Excessive stormwater flow |
| Aprill 14 | 3.5 | 40,204 | Excessive stormwater flow |
| April 19 | 1.7 | 5,419 | Excessive stormwater flow |
| April 20 | 7.7 (5.0 active)* | 16,877 | Excessive stormwater flow |
| April 26 | 5.3 | 23,868 | Excessive stormwater flow |
| May 1 | 2.2 | 9,520 | Excessive stormwater flow |
| May 3 | 4.5 | 10,087 | Excessive stormwater flow |
| May 25 | 2.7 | 23,828 | Excessive stormwater flow |
| June 10 | 0.33 | 55 | Excessive stormwater flow |
| June 20 | 3.7 | 35,985 | Excessive stormwater flow |
| July 17 | 7.1 | 69,573 | Excessive stormwater flow |
| August 17 | 1.4 | 8,332 | Excessive stormwater flow |
| October 16 | 1.1 | 2,920 | Excessive stormwater flow |
| October 27 | 4.4 | 42,424 | Excessive stormwater flow |
| October 31 | 6.25 | 95,650 | Excessive stormwater flow |
| December 14 | 2.25 | 14,228 | Excessive stormwater flow |
*More than one bypass occurred over this total amount of time due to one rain event. Active hours denote the time the bypass process was activated.
| Date | Duration (hrs) |
Volume (m3) |
Reason |
|---|---|---|---|
| January 12 | 4.25 | 90,709 | Excessive stormwater flow |
| April 16-17 | 16.95 | 729,819 | Excessive stormwater flow |
| June 24 | 4.10 | 99,410 | Excessive stormwater flow |
| August 7-8 | 3.72 | 127,350 | Excessive stormwater flow |
| November 1-2 | 7.55 | 244,510 | Excessive stormwater flow |
| November 26 | 9.86 | 264,440 | Excessive stormwater flow |
| Date | Duration (hrs) | Volume (m3) | Reason |
|---|---|---|---|
| January 11-12 | 17.6 total (4.7 active)* | 13,249 | Excessive stormwater flow |
| February 20 | 14.9 total (7.6 active)* | 14,131 | Excessive stormwater flow |
| February 21 | 3.3 | 956 | Excessive stormwater flow |
| April 3-4 | 6.5 | 31,962 | Excessive stormwater flow |
| April 16-18 | 46.5 | 332,131 | Excessive stormwater flow |
| April 25 | 4.6 | 142,65 | Excessive stormwater flow |
| June 13 | 0.75 | 1,200 | Excessive stormwater flow |
| June 24 | 3.5 | 23,772 | Excessive stormwater flow |
| July 5 | 1.5 | 8,983 | Excessive stormwater flow |
| July 22 | 0.5 | 1,377 | Excessive stormwater flow |
| July 24 | 0.6 | 325 | Excessive stormwater flow |
| August 6 | 1.8 | 11,556 | Excessive stormwater flow |
| August 7-8 | 5.7 | 35,581 | Excessive stormwater flow |
| August 17 | 0.8 | 2,207 | Excessive stormwater flow |
| August 21 | 3.25 | 13,499 | Excessive stormwater flow |
| September 10 | 2.7 | 1,428 | Excessive stormwater flow |
| October 2 | 0.2 | 418 | Excessive stormwater flow |
| November 1-2 | 8.75 | 43,713 | Excessive stormwater flow |
| November 26 | 2.5 | 13,736 | Excessive stormwater flow |
*More than one bypass occurred over this total amount of time due to one rain event. Active hours denote the time the bypass process was activated.
Bypass information can also be found in the Ashbridges Bay and Humber Treatment Plant Annual Reports.