The Sewer Utility collects and treats wastewater (also known as sanitary sewer) from City of Medicine Hat customers.

The utility ensures all treated wastewater meets the rigid safety, environmental, monitoring, recording and reporting parameters of federal, provincial, wastewater industry and local standards. The Sewer Utility also plans and implements infrastructure expansions and upgrades to meet planning needs, as well as supports approved local development objectives.

Mandated by the Sewer Bylaw #1541, both the City of Medicine Hat  and sewer customers are expected to adhere to the regulations set forth in the bylaw. The utility is also regulated by Environment and Climate Change Canada (ECCC) and Alberta Environment and Protected Areas.

General sanitary sewer information

Help Prevent Sewer Backups

If you are experiencing a sewer backup, it’s most likely due to a blockage in the sanitary sewer service line between the house and the City’s sewer main.

Sewage backup usually first arises within the sanitary sewer system. If it happens, discharge may appear around the cleanout and/or main drain in your basement. Various materials frequently flushed or poured down the drain can harm the pipes that connect to city sewers as well as the sewer system. Every property owner connected to the sewer system can be a potential contributor to sewer problems, and a potential victim of those same problems.

In order to prevent pipe and sewer blockages and to avoid costly clean-up bills, the only items that should be flushed down your toilet are human waste and toilet paper.

To control the degree or amount of backup:

  • Stop using your plumbing fixtures until you have the sewer line cleaned out.
  • We recommend that you call a local plumber / drain cleaner or rent a machine yourself to clean out your sewer line at your own expense.
  • You may also choose to contact Environmental Utilities to dispatch City field operators to clean out your sewer, however please note that fees may apply.

What is the most common cause of sewer blockages and what can I do to prevent them?

Most sewer blockages happen when materials that DO NOT disintegrate are flushed into the sewer system (by way of sink, tub/shower or toilet etc.). In addition these materials often coat the inside of the sewer lines over time, causing blockages that sewage cannot pass through.

“Flushable” wipes combined with Fats, Oils and Grease (FOG) and at times roots in sewer pipes and mains cause blockages and damage to private plumbing and City infrastructure. 

These costly problems can be avoided if we all become more mindful of what we are flushing down the sewer and a good start would be to stop the flushing of wipes.

The "do not flush" list 

The following items should not be flushed down the sewer system:

  • Facial tissues (Kleenex)
  • Baby wipes
  • “Flushable” wipes
  • Disinfectant wipes
  • Hand wipes
  • Toilet bowl scrub pads
  • Dusting pads
  • Napkins (paper or cloth)
  • Diapers
  • Paper towels
  • Cotton balls and cotton swabs
  • Sanitary napkins, tampons, and condoms
  • Dental floss – or any other string items
  • Egg shells, nutshells, coffee grounds (these are much better suited for your compost),
  • Fats Oils and Grease (FOG)
  • Hair and wigs
  • Clothing
  • Plastic of any kind
  • Cigarette butts
  • Medicines or pharmaceuticals, medical sharps (return these to your Pharmacy)
  • Adhesive bandages such as Band Aids or cloth bandages
  • Toothpaste tubes
  • Cat litter or deceased pets
  • Paints, varnish, paint thinner, or automotive fluids
  • Poisons and hazardous waste
  • Glass
  • Cell phones
  • Jewelry
  • Garden wastes, wood, sawdust, or shavings
  • Food scraps and bones
  • Broken dishware
  • Toys and game pieces

This is not a complete list but provides examples and can be used as a quick reference when you are deciding whether to flush, toss, recycle or return an item. Download the Recycle Coach App to learn more about how to properly dispose of various materials.

"Flushable" wipes

“Flushable” Wipes may swirl down the toilet with ease; however they don't disintegrate and are creating serious problems as they try to work their way through the sewage system.

Some wipes may make it through the lift stations, eventually landing at the Wastewater Treatment Plant. However, most wipes and other materials are often the cause of sewer backups in City sewers, basements of homes and businesses.

In addition to causing backups, this also damages City equipment. Wastewater Treatment Plants are not designed to accept anything other than human waste and toilet paper. Wipes and other debris flushed down the sewer system become entangled in pumps and equipment within the Lift Stations and Wastewater Treatment Plant. These damaged pumps have to be replaced or repaired, which can increase maintenance costs for the Utility in turn costing rate payers hundreds of thousands of dollars.

Unfortunately, although packaging may say wipes are “flushable” - in reality they should not be flushed at all.

Most “flushable” wipes are designed with fibers that take a long time to break down in water. For sewer systems to operate efficiently, the break down process needs to begin immediately. Labeled as a cleaner alternative to toilet paper, the wipes have been estimated to cost Canadian tax payers millions of dollars each year by clogging sewers.

At this time there is no standardized testing for these wipes to make sure they will break down in the sewer system and will not become tangled in lift station pumps or cause blockages in the sewers. With there being no current standard, wipes can claim to be “flushable” when in fact they should not be flushed at all.

What can I do to prevent these problems?

These costly problems can be avoided if we all become more mindful of what we are flushing down the sewer and a good start would be to stop the flushing of wipes.

Fats, oils and grease (FOG)

FOG can be comprised of animal fats, vegetable fats, oils and grease used to cook and prepare food. When any type of FOG is washed down the drain, it acts like glue inside the sewer pipes and mains.

Over time, the buildup of FOG, combined with other debris like food and wipes can block the entire pipe, subsequently causing sewer backup in your home, neighbouring homes or businesses. The damage caused by FOG can be quite serious with the cleanup being costly to both residents and the City.

What can I do to prevent these problems?

  • Avoid pouring FOG down your drain, rather choose to dispose of FOG in the garbage.
  • Wipe pans and dishes using paper towel and pour FOG (i.e. turkey fat, bacon grease etc.) into a disposable can or jar until cool.
  • Dispose of cooled FOG and saturated paper towels in your household garbage.
  • Review the City's Source Control Program page for more information regarding the City's effort to reduce FOG in the sewer system.


Tree root blockages

Tree roots can enter at joints, breaks or leaks in the sewer service or main line and cause blockages. If you suspect tree roots are causing sewer backup problems, contact a local plumber / drain cleaner to cut out the tree roots. Alternatively you can call us to cut out the tree roots, but please note that fees may apply.

If root infiltration is identified, a plan to eliminate or control the root growth should be implemented. Note: The City is responsible for root infiltration on public property piping occurring from public property trees only. If the investigation indicates root infiltration on private property, the homeowner or tenant is responsible.

Sewer main backup
On rare occasions, a blockage can occur in the City’s sanitary sewer main. If the blockage is not detected in time, sewage from the sewer main can backup into homes through the cleanout. The rate at which the backup occurs can be slow or rapid but most always occurs without water usage. If you suspect a sewer main backup please call us at 403-529-8176 immediately.

Sanitary sewer services

An adult over the age of 18 must be in attendance for the entirety of the service being completed for all sewer related services provided by Environmental Utilities field operators whereby house access is required.

Sewer backup / blockage removal

If your sanitary sewer service line from the house to the sanitary sewer main in the street is plugged or showing signs of backup, you have the option to contact a local plumber / drain cleaning service or Environmental Utilities.

Effective since April 1, 2020, Environmental Utilities charges a fee to clear sewer blockages on private property. City field operators will clear the blockage during business hours Monday to Sunday between 8 a.m. and 4 p.m. For fee information, contact Environmental Utilities at 403-529-8176 during business hours.

If the problem is in the evening / overnight (from 4 p.m. to 8 a.m.), you may choose to call a local plumber / drain cleaning service, or wait until business hours for Environmental Utilities field operators to attend. Note that, as above, fees may apply for City field operators to attend.

The service performed by Environmental Utilities is contingent on there being proper access to the sewer cleanout and plumbing installed in your home. If the field operators are unable to access the internal sewer cleanout, it will be recommended that you contact a local plumber / drain cleaner. If an external sewer cleanout is located at the property line, field operators will clean the City owned portion of the sewer service at no cost to the homeowner.

Sanitary sewer main flushing

The sanitary sewer collection system will be flushed in the event of a sewer main blockage or overflow. The City has a routine sewer main flushing program that is carried out year-round to minimize the chances of backup in the mains or overflow from a sanitary manhole.

CCTV inspection

CCTV (closed circuit television) Inspections are completed on sanitary sewer services and mains to assess the condition of the sanitary sewers. The CCTV inspections help determine whether repairs are required or if there is a problem within a sewer line that requires attention. Should you be experiencing frequent sewer backups and are unable to determine the cause, it may be recommended that you have a camera of your sewer service line completed. Results will be provided to the homeowner and follow-up by Environmental Utilities supervisory staff completed as necessary. Please note that CCTV Inspections are by appointment only and fees for a CCTV Inspection may apply.
Sewer line locates 

If you are planning to dig or excavate the ground in any way, it is your responsibility to submit a locate request before you dig.

Line locates

Sewer maintenance and monitoring programs

Sanitary sewer main flushing operations

We are currently flushing the sewer in: Zone D

Please Note: In addition to the routine schedule, there may be additional flushing completed in some areas of the City requiring more frequent attention. Unless the flushing activities are expected to last more than one day, that specific zone will not be noted above for these locations.

Sewer Flushing Zone Map

The flushing program is an integral component to the sanitary sewer collection system as it helps clean and remove residual debris and build-up from within the mains. Flusher/Vacuum combo trucks are used to flush water through the sanitary sewer main at a high velocity to remove debris and build-up from the pipe walls.

Materials and substances such as FOG (fats, oils and grease) and wipes (even those labeled as "flushable") combined with root infiltration, rocks and dirt are common causes for the build-up within a sanitary sewer main. A routine flushing program minimizes the chances of the build-up in the mains from becoming a blockage, potentially causing sewer backup or overflow which pose significant health and environmental concerns.

The goal of any sanitary sewer flushing program is to minimize service calls and sewer backup, caused by main blockages. However, the program cannot be successful without the participation of our customers. Be mindful of what you are flushing into the sanitary sewer main and only flush what the sanitary sewer is intended to collect.

The sewer main flushing process can cause pressure fluctuations within the sewer service laterals leading into homes or businesses and can potentially suck out the standing water in the p-traps. P-traps that have dried out can become smelly, releasing a sewer odour into your home or business. Simply fill your p-traps with hot water to eliminate the smell.
Tree root removal

Part of the City’s routine maintenance program is the removal of tree roots in affected areas of the sanitary sewer mains. Tree roots, if left undisturbed in the sanitary sewer mains and services, will completely block the sewer causing sewer backup. Tree roots thrive in the warm, moist sanitary sewer mains that are full of nutrients which attract the tree roots. As tree roots expand, they can cause breaks and large cracks in the sanitary sewer lines which significantly decreases the integrity of the pipe.

The most common way to clear roots from a service line is through the use of root cutters and augers. The Sewer Utility is only responsible for city owned infrastructure, providing a courtesy service where applicable. However, root removal via herbicide application is the best option within the sanitary sewer mains being that they are so much larger than a service so a cutter or auger may take too much time.

If a section of a sanitary sewer main is found to be affected by tree roots, licensed operators may administer herbicide to clear the root infiltration. 

Wastewater Treatment Plant

General info

Wastewater treatment, also known as water reclamation, is a multi-stage process that cleans and restores wastewater. It removes organic matter, solids, nutrients, disease-causing organisms, and pollutants from the wastewater. After treatment, the cleaned water is released into a body of water.

In Medicine Hat, the Wastewater Treatment Plant (WWTP) handles sewage from homes, businesses, and industries in the area. The plant is located east of the city, near the South Saskatchewan River. Certified operators run the plant year-round, ensuring that the treated water meets strict industry, provincial, and federal standards.

The plant takes daily 24-hour composite samples from both the inlet (incoming wastewater) and outlet (treated water) sides. If the wastewater composition varies from the norm (for instance, due to hydrocarbons), the treatment process is adjusted. The final treated water is tested daily before being discharged into the river.

The Wastewater Treatment Plant can handle 36,565 cubic meters per day, with a peak capacity of 74,000 cubic meters per day. Currently, the average daily flow is around 26,000 cubic meters, with an average daily peak of 48,000 cubic meters.

History of the Wastewater Treatment Plant

Existing five lagoons (now referred to as storage ponds) constructed to provide treatment for the city’s wastewater.


Upgrades to the lagoons by adding aeration to lagoons 1 to 4. Final effluent from the lagoons at this time was discharged to the South Saskatchewan River from the North end of number 5 lagoon.


A primary treatment plant was constructed upstream of the lagoons to include the administration building, laboratory, Headworks building for screenings and grit handling, primary clarification, biosolids press and an effluent pumphouse.

  • At this time the lagoons became the secondary treatment for the wastewater.

A secondary treatment phase added to include, trickling filters, solids contact process Phosphorous removal and Chlorine disinfection.


Two Ultraviolet reactors added, to replace Chlorine disinfection, with room for a third reactor when required as Medicine Hat grows in population.

  • Lagoons now serve the purpose of storage ponds before discharging the effluent to the South Saskatchewan River.
  • One lagoon remains empty to use as overflow during times of extreme high flow into the WWTP.

Laboratory upgrades completed to include new counters, plumbing alterations, and additional sinks.


An 800kw backup generator capable of powering the entire WWTP in the event of a loss of power was installed.


The third ultraviolet reactor channel was installed and put online.

Plans for future upgrades include new bar screens and grit handling in the Headworks building.

Frequently asked questions

What do I do if my sewer is backing up? 
  1. Immediately stop all water use. Sewer backups are typically caused by a blockage either in the plumbing within your home or business or in the sewer lateral between the building and the street. Turn off washing machines, dishwashers, showers and anything that uses water.
  2. Contact a local plumbing contractor. You may choose to contact us during business hours – Monday through Sunday between 8 a.m. and 4 p.m. – however please note that service fees may be applied to your utility account for City staff to attend. 
Why is the City charging for the sewer cleaning service now? 
With the current economic times the City can no longer sustain a business plan that offers these types of services without a charge. The City believes that City departments should not compete with local businesses. This initiative should give more business back to the local plumbing companies. 
Will the City offer all of the same sewer maintenance services? 
For a fee, the City will offer Tree Root & Blockage Removal, Tree Root Foaming and CCTV Camera services. If warranted, Sewer Service Flushing will also be offered at an hourly fee. 
How much will it cost for City staff to attend for a sewer backup or camera inspection? 
Please contact us at 403-529-8176 to inquire about and discuss the new fee schedule. 
How will the fees be charged? 
The fees will be charged through a service order request on the utility account for the affected address. 
Will City staff still attend for routine maintenance? 
We no longer offer routine sewer maintenance. We recommend that you contact a local plumber or rent a machine yourself. 
What if a plumber says the blockage is on City side? 
Contact us during business hours. We'll dispatch a crew to your residence to clear the blockage and determine where the problem has occurred. Please note, fees may apply. 
Will the new services be offered after hours? 
City staff will attend to complete these services during regular business hours – Monday through Sunday between the hours of 8 a.m. and 4 p.m. 
What if I experience a sewer backup overnight? 
We recommend that you call a local plumber to attend after business hours. 
What will the City crew do to stop the sewer backup? 
The crew will check to see whether the sanitary sewer main located in the street is flowing properly. If there is a blockage in the main, a crew will be dispatched to remove the blockage in the sanitary sewer main.

If the sewer main is flowing properly, the crew will clear the blockage in the service line by using a machine that goes through a 4-6 inch cleanout access.

If the sewer backup occurs after-hours, a callout operator will only check that the sewer main is flowing and will not attend inside the home or business.

What should I do if I smell sewer odour but don't see sewer backup? 
When sewer gasses are present inside the home, it is usually due to one or more P-traps becoming dried out. The water in a P-trap will evaporate if the fixture is not used for an extended period. Seldom used bathrooms or utility sinks are commonly the source of sewer odors.

The simple solution to this problem is to periodically run a small amount of water (one or two cups) into the drain to refill the trap.

What is the purpose of a P-Trap? 
Every water fixture in your house has a P-trap. This "U" shaped pipe is clearly visible under sinks, and is present in some form on all lines draining to the sewage system. The "U" shape holds water, creating a seal and preventing gases from backing up from the sewer into the house through the drain. 
What is my responsibility as a home or business owner? 
It is the home or business owner's responsibility to maintain the sewer lateral from the home or business to the property line. The city is responsible for maintaining the sewer lateral from the sewer main to property line as well as the sanitary sewer mains themselves. 
What do I do if I think City trees are the reason for sewer backup? 
Depending on where the root infiltration is located, it is the home or business owner's responsibility to maintain the sewer lateral on private property. Some drain cleaners or plumbers can auger the roots out of the sewer line. Also, you can purchase root herbicide at a hardware store and administer to remove the roots from within the sewer line while not harming the tree. Sewer Utility staff is responsible for the sewer lateral and sanitary sewer main on public property.

If you have an inquiry about the tree itself, contact the Parks and Recreation Department at 403-529-8333.

What can I do to prevent roots from entering my sewer service line? 
Maintenance (foaming/root cutting) is an option but is only a very short term solution. The only way to ensure roots do not enter your sewer service line is to either replace the line with a PVC sewer pipe which involves excavation, or by CIPP lining of the service. CIPP stands for Cast-in-Place-Piping. During this process, a resin-impregnated sock is introduced into the sewer service along with a plastic bladder. This can be installed through a standard sized cleanout in the basement of the residence, therefore no digging is required. The bladder is then filled with water and heated up causing the resin to cure. The bladder is then burst to drain the water and then removed. What is left is a hard monolithic liner that is root proof. Note that not all sewer lines will accept a liner. Lines with an excessive sag cannot be lined as they will not properly cure. For more information contact us at 403-529-8176. 
What causes blockages to occur? 
Blockages can occur for two reasons:
  1. Accumulation of material inside of the pipe. Draining improper substances through the sewer, such as kitchen fats, oils and greases (FOG), food, sand, clay or mud, can cause a build-up and blockage in otherwise properly constructed sewers. However, the proper operation of a sewer lateral requires that the line be constructed "on grade", that is with a consistent slope. High or low areas along a line will cause small amounts of greases, soap scum and other material to accumulate, eventually causing a blockage. A clean-out provides the homeowner or sewer drain contractor an access point for sewer line maintenance.
  2. The presence of sand or roots entering the line through a break or other damage to the line. Tree roots will seek out sources of water, such as sewer lines, and will enter even the smallest cracks in the line. Roots will inevitably clog a sewer line. Larger cracks will not only allow roots to enter but will cause sand and dirt to enter the line, blocking the flow. As dirt flows into the line, a small "sink hole" or depression appears in the ground above the break. These sink holes almost always indicate a problem with a sanitary sewer line or a storm drain, and therefore should be investigated or reported.
Where does FOG (fats, oils and grease) come from that gets into the sanitary sewer system? 
Mostly from cooking oils and fats, condiments, meats and meat by-products that are disposed of down the kitchen drains and through the dishwasher drain. 
What can I do to help reduce FOG? 
  • Pour fats, oils and greases into a can or empty jar, cool and discard it into the garbage instead of pouring it down the drain.
  • Use garbage disposals sparingly. This will only grind by-products into smaller chunks that will still get stuck in the lines.
  • Scrape plates into the garbage instead of the garbage disposal.
  • Dry wipe greasy pans before washing them. 
What is a sewer lateral? 
A sewer lateral is a sewer pipe that connects your home or business to the sanitary sewer main in the road. 
How can my sewer lateral be accessed? 
Your sewer lateral can be accessed through your clean-out. A clean-out is typically found in your basement where the lateral exits your home or business. Generally, a clean-out has a threaded cap that is four to six inches in diameter. 
What is the purpose of the roof vent? 
All houses have plumbing vents that extend through the roof. These vents allow air to flow both in and out of the house plumbing system, helping water to flow through the pipes. Working in combination with the P-traps, gases from the sewer system are vented safely through the roof. 
What can I flush down the toilet? 
Human waste and toilet paper only!

A number of liquids are flushed down the toilets that upset the chemistry of our wastewater treatment plant and can cause volatile conditions in our sewers. A few examples are medications, chemicals, oils, paints, paint thinners, antifreeze, batteries and gasoline. There are many materials that cause blockages like grease, diapers, cat litter, dental floss, feminine products etc. that also should not be flushed down the toilet.

The Wastewater Treatment Plant takes pride in protecting our receiving water. We as a community need to be conscious about what we are washing down our sinks and flushing down our toilets so that we can continue to live in a safe, clean environment.

Where does the water leaving the Wastewater Treatment Plant go? 
The water discharged from the Wastewater Treatment Plant is referred to as effluent. The City of Medicine Hat's wastewater effluent is discharged into the South Saskatchewan River. 
If I flush a fish down the toilet, will it make it to the river? 
Not to upset any children who hope their pet will swim free in the South Saskatchewan River, but we do have to say no. The fish will travel through many pipes, pumps and screens eventually ending up in the biosolids removed from the Wastewater Treatment Plant. The biosolids are then taken up to the Waste Management Facility and turned into compost. 
What is a Sewer Backflow Preventer/Sewer Backwater valve? 
A sewer Backflow Preventer/Backwater valve is a device installed on the sewer service line at a location just before it exits the building. It is, in effect, a one way valve that will allow the sewer flow from the property out to the sewer main in the street. It is designed to prevent sewage coming back through the sewer service line if the sewer main in the street is blocked and sewage starts to back up in the sewer main located in the roadway. 
Should I have a Sewer Backflow Preventer installed? 
Installation of a Sewer Backflow Preventer/Sewer Backwater Valve is up to the discretion of the homeowner. After the 2013 flood, homes that were located in the imminent flood zone were recommended to have a Sanitary Sewer Isolation valve installed; however, in the end, the decision to have a valve installed on the sewer line was and will continue to be left up to the homeowners. 
Who do I call about Storm Sewer problems? 
The City's Municipal Works Department maintains the storm sewer system. Storm sewers can be identified by the storm sewer manholes on the street and the frame and grates/catch basin grates located on streets near the curb and gutter. To report a storm sewer problem please contact the Municipal Works Department at 403-529-8177.