Frequently Asked Questions

Thanks for taking the time to learn more about this important topic. If you don't see the answer you are looking for, please contact customer service at 613-546-0000, Monday to Friday, between 8 AM to 5 PM.

Health questions:

Is it safe to swim after heavy rains?

The Kingston waterfront is a clean, safe place to swim, fish or boat. However, there is an added risk of pollution that can occur after heavy rainfall due to storm water run-off (contributing pollutants from agriculture, animals and humans) and sewer overflows. Our partners at KFL&A Public Health caution that lake bacteria levels are higher up to 48 hours after a heavy rainfall and swimming is not recommended during that time.

Is it safe to swim during a sewer overflow?

Swimming during a sewer overflow is not recommended. When a sewer overflow occurs, the water could become contaminated with bacteria and chemicals, and swimming in the water could make you sick.

The risk of illness is highest if you swallow the water. However, ear, eye or skin infections could also occur if you swim in the water during, or shortly after, a sewer overflow has occurred. If you have contact with the water within 48 hours of a sewer overflow, it is recommended that you wash yourself well afterwards.

Can pets swim in or drink from the lake during a sewer overflow?

Animals can usually drink from and swim in lakes and rivers without getting sick. However, they may not be immune to all microorganisms or chemicals that may be present during a sewer overflow. If your pet goes in the water during a sewer overflow, you should bathe him well afterwards.  Consult your veterinarian if your pet becomes ill.

Is it safe to eat fish that is caught during a sewer overflow?

Contaminants that end up in our lakes and rivers can be ingested by fish and in turn by people who eat the fish.  If you catch fish near a sewer overflow, cook the fish to 70O C (158O F) to kill any harmful bacteria.  For more information, read the Eating Ontario Fish Guide from the Government of Ontario.

Is water tested during /after a sewer overflow?

Water is not tested during or after a sewer overflow.  It takes at least 24 hours for a laboratory to analyse water samples, therefore, results would not represent the current status of the water.

How long does it take for the water course to recover from a sewer overflow? 

The recovery period from a sewer overflow is dependant on many factors, including how heavy and long the rainfall was, how much sewage was discharged during the overflow, the wind, and water current patterns at the time of the incident.  It is recommended that you wait at least 48 hours after a sewer overflow to resume normal use of the water.

Technical questions:

Do overflows affect drinking water quality?

Ontario has strict water quality standards, which Utilities Kingston continually meets and exceeds, including after an overflow. There are a series of filtration, treatment, monitoring and backup systems in place to continually supply high-quality drinking water to every home and business within the urban area of Kingston. As well, intakes for raw water are quite a way offshore and are not significantly impacted by near-shore water quality.  View our annual water quality reports.

Is there anything we can do to help reduce the chemicals that are released into our waterways during a sewer overflow?

When people dispose of hazardous chemicals and medications down a storm drain, they make their way into our waterways. Although the chemicals are diluted with water when a sewer overflow occurs, chemicals do not break down easily and can be harmful to people and animals. 

Never pour household chemicals, paint, lawn care products or automotive fluids into the storm sewers.  Instead, use natural cleaning supplies when possible, return unused medications to your local pharmacy and take leftover paints and chemicals to the hazardous waste disposal facility. Reducing the use of lawn care chemicals, and picking up pet waste will also help protect our waterways.

For proper chemical disposal instructions, see the Hazardous Waste section in Recycling/Special Diversion at the City of Kingston’s website.

Additionally, the wastewater treatment process is designed specifically to treat domestic sewage and human waste. It is not designed to treat the huge variety of chemicals that are present in other day-to-day products. You should never dispose of materials like oils, pesticides, paints and cleaning products down a drain or your toilet. 

Learn more from our pages on knowing what to flush and preventing storm water pollution.

What is a sewage or sewer overflow?

A sewage or sewer overflow refers to a short-term event where some amount of sewage leaves the normal wastewater collection and treatment process and discharges to the local environment instead.

What types are there and why do they occur?

There are various types of sewage overflows, generally named depending on where the overflow took place:

  • A combined sewer overflow, or “CSO”, is an overflow of diluted sewage from the combined sewer system. This occurs because the combined sewer is full and the pipes no longer have the capacity to move the contents to the treatment plant. This happens when more storm- and groundwater enters the collection system than the pipes were designed for. Combined sewers are meant to accommodate some storm-water runoff, but not large amounts. The sewage is diluted to some degree by storm-water.
  • A sanitary sewer overflow, or “SSO”, is an overflow of diluted sewage from a separated sewer system. This occurs because the sanitary sewer is full and the pipes no longer have the capacity to move it to the treatment plant. The cause is “extraneous flow”, or in other words, too much storm-water and groundwater getting into the system. The result is that the designed capacity is exceeded. In contrast to combined sewers, separated sewers are not meant to accommodate much storm-water runoff, although a small allowance is always made to account for leakage into the system.
  • A sewage bypass is a release of partially-treated wastewater, specifically from a treatment facility.  In this case, part of the treatment process is “bypassed”.  This means that what is discharged to the environment is a mixture of fully-treated wastewater and partially-treated wastewater.  In Kingston, it is often the secondary treatment process that is bypassed when such an event occurs, so the final discharge is a blend of primary and secondary treated wastewater.  It all receives disinfection prior to discharge to the environment.

The above are the primary types of overflows, but overflows of sewage, combined sewage, or partially-treated sewage can take place at other features in the wastewater system. These places can include at pumping stations and storage tanks. In general, these are a result of when the capacity of the system is exceeded during large wet-weather events, or if there is a power or mechanical failure at a facility.

Why do overflows happen?

Overflows happen when the capacity of the system is exceeded because too much sewage and/or water is entering the pipes. When this happens, the flow capacity of the pipes is exceeded and the sewage level in the collection system rises in response. When the sewage level gets to a certain height (where a relief overflow pipe is located), the sewage then ‘bypasses’ or 'overflows' from the normal flow path to the treatment plant. It goes to the adjacent storm sewer system or directly to the environment instead.

Overflow pipes were physically built into the system in the 1950’s (and later) as fail-safe mechanisms, to prevent the sewage levels from getting high enough to back up into basements. Overflow pipes are a type of built-in safety mechanism as discharge of sewage to the environment was considered the lesser of two evils, in comparison to sewage in basements...and still is to this day.

What are combined sewers?

Combined sewers were built to collect both sanitary wastewater (e.g., from your home) as well as surface runoff (e.g., from stormwater) in one pipe. They do the job of both sanitary and storm sewers with one pipe instead of two. Because they collect storm runoff, which can either be minimal or substantial based on the severity of the storm, the capacity is exceeded from time to time. Combined sewers are no longer built in the City of Kingston, and while we have significantly reduced the area serviced by combined sewers, the City still has about 20 kilometres left (as of 2017).

To learn more about combined sewers, refer to the webpage What Is Wastewater.

Is sewage overflowing a new problem?

Sewage overflowing is not a new problem. It is a historic remnant of the evolution of the sanitary sewer system in the City of Kingston. Overflows have been occurring for decades. It is a problem that exists in most major cities around the world. The City of Kingston is doing a lot to reduce the overflow problem.  To find out more, view our page on ways we are reducing the problem.

Can you plug the problem?

It is not that simple.

Prior to plugging an overflow, Utilities Kingston carefully evaluates the cause of elevated flows and addresses them with caution. This is because when sewer system capacity is exceeded, and if no overflow relief points are present, the level will rise in the collection system. Then sewage will back up into household basements and flood the streets - a problem we all really want to avoid! 

By default, all or most of the upstream combined sewers must be separated to even consider plugging an overflow point. Continued monitoring then confirms whether or not major surcharging still occurs at the overflow point.

Some overflows are an operational fail-safe feature to protect basements, for example. The ability to overflow is a common safety consideration of most sewage pumping facilities, even those built today in fully-separated sewer areas. In case of extreme weather or other conditions, relief points provide an alternative outlet for sewage should the facility’s pumps fail to operate. 

Can you control an overflow?

In most locations, Utilities Kingston has no control over the amount and timing of an overflow event. Most overflows are static structural features that were built into the sewer system during original construction. There are no gates or valves that can be used to start or end an overflow event.

How much rain does it take for sewage overflows to occur?

It depends on the specific location. There are some local sewer overflows that activate even with moderate rainfall and then, there are others that require a heavy rain or large rain during a snow-melt event. 

Our sewer overflow log provides an archive of bypasses and the amount of local precipitation at the time. 

How much sewage typically overflows?

An archive of bypass events can be found on the Utilities Kingston sewer overflow log, shown in cubic metres.

While we would prefer to never have sewage flowing into the environment, the City of Kingston is meeting benchmarks established by the Ministry of the Environment and Climate Change “Directive F-5-5”. There is room for improvement.

  • Statistically speaking, the City of Kingston meets the basic volumetric criteria established by F-5-5, which is to capture “90% of wet-weather flows in an average weather year”. In fact, the latest Master Plan indicates that relative to an average year, 96% is captured and 92% is captured in a wetter-than-average year.
  • Where the City of Kingston wastewater collection system has room for improvement is the frequency of occurrence and duration, which for many locations, occurs more than twice per “water contact” season. These are locations that receive higher priority for action intended to reduce the frequency, duration and volume of bypass events.

Regardless of whether the system meets or exceeds F-5-5 criteria set forth by the MOECC, Utilities Kingston recognizes that any amount of sewage overflow is too much.

Utilities Kingston has established a voluntary and more stringent criterion of achieving NO SEWAGE OVERFLOWS in a WETTER-THAN-AVERAGE year. This is reflected in the new (WSP, 2017) and former (CH2M, 2010) wastewater master plans and the numerous sewer separation projects we undertake from year to year. It is an aggressive, longer-term objective.

One significant and recent advancement is the installation of 13 new overflow monitoring stations that allows monitoring of overflows. Utilities Kingston is better able to see how the volume and frequency of overflow events changes from year to year, and how it responds to sewer separation and other source reduction projects in the contributing sewer service area.  

Why are you making this information public?

We are committed to sharing overflow data as it occurs. This will allow recreational water users to make informed decisions to help protect their health and safety.

Sewage overflows are not something that the industry is proud of, but it is an aspect of the sewer system that has been inherited from well over 100 years of sewer construction. It is acknowledged as a historic and current problem, and Utilities Kingston continues to undertake projects to address the challenges of sewage overflows. 

Monitoring data is used to track the effectiveness of improvements and the reduction in overflows over time. Data is available from the Utilities Kingston sewer overflow log.

What are you doing to reduce or eliminate overflows to the environment?

Utilities Kingston has been actively working to reduce overflows since the 1990’s, including the following projects and improvements to the sewage collection system:

End-of-pipe controls:

  • Construction of three large active CSO storage tanks that intercept bypasses from select trunk sewer locations (King Street at Collingwood Street, King Street at George Street, and Emma Martin Park on Cataraqui Street).
  • Construction of six small inline CSO storage tanks on select combined sewer streets in Sydenham Ward (West Street, Lower Union Street, Gore Street, Earl Street, William Street and Clarence Street).
  • These storage tanks capture at least some of the sewage that would otherwise overflow to the environment. Smaller overflow events are fully captured and returned to the sanitary system after the event has ended. Larger events that fill the tank and exceed its capacity discharge to the environment.

Conveyance controls:

  • Increasing sewer capacity by twinning (adding a new sewer main in parallel to the existing one) or constructing two sewer mains. Examples include sewer twinning of the Harbourfront Trunk Sewer and constructing the River Street Pump Station twin forcemain across the Great Cataraqui River.
  • Upgrading pump capacity at various pumping stations under the influence of combined sewers or sewer systems with excessive extraneous flow (Dalton Avenue, King-Portsmouth, King Street and River Street). Increased capacity within the pipe network and at major pumping facilities allows more combined sewage to be conveyed to the wastewater treatment plant before bypassing occurs.

Source controls:

  • Extraneous flow reduction projects in the Dalton Avenue Pump Station service area and the King-Portsmouth Pump Station service area.
  • Sewer separation. During road reconstruction projects, combined sewers are replaced with separate storm and sanitary sewers. There has been a 35 per cent reduction in combined sewers since 2008. The current 2015-2018 capital plan will reduce combined sewers by an additional 10 per cent.
  • Preventative Plumbing Program. This is a financial incentive program that in part, assists homeowners in redirecting their homes storm and groundwater drainage away from the sanitary sewer system (and the storm system too!). Learn more and apply.
  • These projects and programs are all focused on addressing the problem at the source, which is storm and groundwater getting into the sanitary sewer system. By removing these sources, the sewer system is better able to handle larger wet-weather events without bypassing.

Get more information on ways we are reducing sewer overflows.

Will reducing overflows help the water and waterfront?

Action taken on reducing overflows will continue to improve water quality in the Kingston area immediately following heavy rainfalls and rapid snow melts. There are, however, many other sources of lake pollution.

In our urban environment, storm water is likely the next biggest culprit. While sewage is deemed to have a bigger impact, storm-water can carry pollutants as well and often similarly contributes to higher bacteria counts and beach closures. You can help reduce the impact of the storm-water collection system on the environment by:

  • Not allowing soapy and dirty wash water from cars, bikes and other things drain into the nearby storm drain.
  • Discharge runoff to the lawn where it can infiltrate into the ground, rather than adding to flow in the storm sewer. This includes downspouts (roof runoff) and sump pump discharge (groundwater). Learn more about runoff pollution and how to prevent it.
  • Never pour paint, oil, chemicals and other substances into the storm drain since they go straight out to the lake. Check the City of Kingston Waste Sorting Lookup for proper disposal.
  • For other preventative measures, check the City’s stormwater resource.

What can I do to help improve the situation?

Sewer overflows are a community problem. The utility is better able to address the problem with participation from residents. You can help by becoming informed about what overflows are, why they occur and what actions you can take to help reduce the problem.

  • Ensure your home and property are not contributing to the problem. Disconnect illegally connected sump pumps, downspouts and foundation drains. They contribute to sewage overflows and basement flooding in your neighbourhood. Utilities Kingston has a financial assistance program to help.
  • Reduce sewer use during heavy rainfalls, particularly in central Kingston where there are combined sewer areas. If possible, avoid showering or doing laundry when rainfall is heavy, for example.
  • Participate in wastewater capital works projects in your neighbourhood by attending public information centres.
  • Participate in the development of the Wastewater Master Plans and Pollution Prevention & Control Plans. Public support will help make reduction of overflows a top priority. 
  • Talk to your City Councillor and let him or her know that more needs to be done to reduce and/or eliminate sewage overflows.
  • Help prevent sewage back-ups in your home and costly break-downs in treatment equipment by knowing what not to flush
  • Help prevent bacteria from entering the waterways with our resource on preventing storm water pollution.

Where can I get more technical information?

Our website provides additional background and helpful programs and information:

Customer service is available Monday to Friday from 8 AM to 5 PM by calling 613 546-0000.

 

Will the overflows you report decrease as you do more work on the wastewater infrastructure?

Yes.  A decreasing trend should be observed.  This doesn’t mean that year-over-year, we will see a decrease.  There will always be variability from year-to-year, based on the randomness of weather, and due to climate change, the possibility of more frequent severe weather events.  

Map questions:

How does the map provide real-time information on overflows?

Each outfall shown on the map has one or more sewage overflow or wastewater treatment plant bypass points connected to it. Each overflow point that displays its overflow status is equipped with real-time monitoring equipment. This equipment tells us, in real-time, when overflows start and when they finish. We send this raw data right to the map so interested individuals or organizations can use the information to make informed decisions about whether to swim, fish or boat.

What does each of the different status symbols on the map represent?

There are five different possible symbols on the map and each one is described below.  

Unmonitored:  The small light grey dots are outfalls to the lakes/rivers that can be a source of sewage overflow to the environment, but are locations that do not yet have the capability of displaying real-time information. Utilities Kingston has been monitoring, to some extent, many locations over the preceding years and we have taken efforts to ensure we have the capability of displaying data for the locations that have overflowed once, on average, every year or more, between 2010 to 2016. These unmonitored locations will be brought online when facility upgrades permit them to be added.

Monitored, but out-of-service: These are black circles on the map. These are locations that have real-time monitoring, but are temporarily out-of-service. They may be out of service for one reason or another, including establishing a new location, general maintenance, testing, calibration or replacement of equipment.

Monitored:  No Overflow: These are green circles on the map.  These are locations that have real-time monitoring and have not registered an overflow event within the last 48 hours.  In other words, there is no overflow at that location nor has a recent overflow taken place there.

Monitored:  Overflow. These are red triangles with an exclamation point.  These are locations that are either are currently overflowing or are no longer overflowing but are still in ‘overflow state’ as part of a larger multi-location “event”.  Operators monitor this status and reduce it to yellow when they are satisfied that events have ended.

Monitored:  Overflow in the last 48 hours: These are yellow triangles with an exclamation point.  This are locations that are no longer overflowing, but have overflowed in the last 48 hours.

How do the symbols change?

Symbols will change as a result in change in the overflow status at each location.

Symbol changes occur as follows:

  • For a location that begins to detect an overflow, the data point automatically turn red (from either green, or yellow) as soon as an overflow is detected.  This happens in real-time as a result of the raw data direct from the sensor. (Automatic, real-time)
  • For a site that was overflowing, the data point change from red to yellow will only occur when an operator, using his or her judgement, defines the event to be over.  (Manual, operator-reviewed).  Sometimes overflows can ‘flutter’ back and forth between overflowing and not, and this eliminates the confusion that may be generated by that flutter.  In addition, overflowing during heavier rains can occur at multiple locations, and operators may not manually end the overflow at a specific location if it is part of a larger multi-location overflow event.
  • For a site that has overflowed in the last 48 hours, the data point will turn from yellow to green automatically 48 hours after the last moment overflow was detected.  (Automatic, real-time)
  • A site will be manually turned to ‘out-of-service’ if there is planned work to be done at the overflow location (maintenance, calibration, etc….) , or near it (road reconstruction, etc..).