Industrial wastewater monitoring program

The City of Airdrie maintains and operates a network of public sanitary collection mains and pumping facilities that transports effluent (sewer) for treatment in Calgary. Well maintained sanitary infrastructure helps to maximize the useful life of the sanitary system, reduces the risk of blockages, protects the environment, and reduces the potential for excessive maintenance.

To protect the integrity of the sanitary system, the City of Airdrie’s Industrial Monitoring Laboratory tests effluent for bylaw compliance.

Please take steps to install or maintain your pre-treatment systems. Instructions for care and maintenance are available for reference.

Training your staff in proper disposal procedures and using environmentally-friendly cleaning supplies are recommended.

How surcharges are calculated

The Industrial Monitoring team collects samples from the sanitary/storm systems from a test point at your business location.  The samples are then analyzed based on parameters set out by City bylaws. 

To calculate the surcharge, the test sample results are subtracted from the concentration limit allowed . This is your over-limit amount. The over-limit amount is then multiplied by the bylaw rate. 

*If your test results are under the concentration limit allowed, you will not receive a surcharge on your utility bill.

The over-limit amounts are added together to calculate your effluent limit overage. This effluent limit overage total is then multiplied by the amount of water consumption per billing cycle. This surcharge is applied to each bill until the next testing results are received.

Example: the effluent limit overage is calculated at 10.050 and the water consumption for the billing cycle is 83 m3. The surcharge amount to the customer is $834.15.

You could be approved for a reduction of the surcharge by applying best practices and providing satisfactory maintenance records to the Industrial Monitoring department.

A grease trap or grease interceptor, is a plumbing device placed on kitchen cleaning fixtures. It should be connected to any fixtures (dishwashing sinks, dishwashers) or drains (floor drain, drains serving self-cleaning exhaust hood and cooking equipment) that discharges wastewater. It collects the fats, oils and grease (FOG) that are washed off cooking appliances and kitchenware. It also acts as a particle separator and allows solids to settle to the bottom.

Grease Trap: <50 gpm (gallons per minute) of flow
Grease Interceptor: >50 gpm (gallons per minute) of flow

An engineer or registered plumber should be able to calculate your gpm/flow rate. Your flow rate can also sometimes be found on your business development permit or plumbing drawings. 

How FOG can affect your business:

If FOG bypasses your grease trap/interceptor, you may encounter complications and problems. These may include reduced plumbing flow, odours, and sewer backup. The results may cost  your business time, money, and customers. These problems can be easily avoided by following a cleaning and maintenance schedule for your grease inceptor that is appropriate for your business.

How to monitor grease trap/inceptor cleanliness:

1. Remove grease trap/interceptor lid.
2. Using a turkey baster, break through the fat layer at the top of the interceptor to determine its thickness.
• If the fat layer is thick, and the grease has solidified, the grease interceptor must be immediately cleaned.
• If the fat layer breaks up easily, squeeze the baster bulb and insert the tip roughly one inch into the liquid. Obtain a sample at this depth, and determine if the contents are FOG or water. Continue by taking a sample 2 inches deep. If this sample contains FOG, take a sample 2½ inches deep. If this sample contains FOG, the interceptor requires cleaning.

This is a simple method to determine whether your grease trap/interceptor is in need of cleaning. It will help ensure compliance with the City of Airdrie Sewer Bylaw, thus saving your business money, time and customers.

Cleaning the grease trap/interceptor:

Cleaning of the grease trap/interceptor can be done by you or a licensed hauler by following these steps:

1. Open the grease trap/interceptor, and suction off the top layer of grease using a wet-dry vacuum or by scooping manually. Once removed, place in an appropriate storage container for later disposal. 
2. Remove baffle and scrape fat/oil off the baffle into the same storage container.
3. Suction out the solids at the bottom of the grease trap/interceptor, and place it in the storage container. 
4. Suction out any water, and discard.
5. Thoroughly clean all four sides and bottom of interceptor using fresh water, and a scraping tool. Rinse out with clean water and suction one last time. Place all waste in the proper storage receptacle for later disposal. 
6. Ensure that the inlet, outlet and air relief ports are clean and clear and that all internal components are working properly. 
7. Properly reinstall all seals, replacing any that are damaged, or cracked. Securely fasten the cover and fill the grease trap/interceptor with clean water to ensure maximum efficiency. 
8. Ensure that you or the hauler record all maintenance, cleaning, and inspection of your grease trap/interceptor. Make certain that if using a hauler, the hauler records the sludge depth and free water depth during maintenance. These records must be kept for a minimum of two years. Failing to do so may result in fines. 

Frequency of cleaning:

The frequency of your grease trap/interceptor maintenance and inspection will vary based on cooking methods, and type of food served in your establishment, as well as its capacity. You can reduce the  need for cleaning by removing the top layer of grease from the interceptor often. This may mean removing the top layer several times a week, if necessary. Even with this preventative maintenance, it is still important to monitor the interceptor to ensure it is not reaching capacity. 

You can also reduce the amount of maintenance needed by training your employees in good management practices in the kitchen to prevent FOG from going down the drain:

• Wipe down all cooking equipment before washing.
• Scrape dishes before washing.
• Recycle used fryer grease. This can be done free of charge by various recycling services.

Food service facilities are a huge contributor to oil and grease in the sanitary sewer system. Oil and grease can accumulate in drainage systems and cause blockages. A grease trap or interceptor is a necessary and important part of your kitchen. It prevents fats, oils and grease (FOG) from entering the wastewater system. FOG can have a negative impact on the environment, and City of Airdrie wastewater systems if not properly disposed of. If you have a grease interceptor installed in your kitchen, you have already taken the first step in preventing problems associated with FOG. However, in order for the grease interceptor to work properly, it must be adequately maintained, and kept in clean, good working order.

The City of Airdrie Sewer Bylaw requires the owner or occupier of an industrial or commercial establishment to keep the grease interceptor in good working condition at all times. It also requires the establishment to keep service records for up to two years, so they may be presented during time of inspection. Failing to install or maintain the interceptor may result in fines and/or surcharges.

Please take the following preventative measures to comply with the Sewer Bylaw:

• Install a correctly sized grease trap/interceptor to remove grease before it enters the sewer system.
• Scrape all dishes into the garbage/organics bin before they are put in a dishwasher or washed by hand.
• Wipe away fats, oils and grease from cooking equipment before washing.
• Ensure kitchen sinks have food strainers/screens.
• Educate staff on grease trap/ interceptor maintenance and proper disposal.
• Keep records of all grease trap/interceptor maintenance.
• Keep a wastewater disposal logbook (along with a grease trap/interceptor record if applicable) for food trucks.

Grease Trap & Grease Interceptor Maintenance Form (pdf)

A grit trap/interceptor or sump is an essential component for commercial car wash facilities. These components separate grit, sand and oil from effluent before it enters the City of Airdrie infrastructure. Grit, sand and oil can have a negative effect on the infrastructure, causing blockages and backups as well as damage to the surrounding environment.

Please take the following preventative measures to comply with the Sewer Bylaw:

• Install a correctly sized sump/grit interceptor to trap debris, sludge and grit and dispose of harmful substance at appropriate facilities.
• Ensure proper drainage. No water draining from the car wash should be going into the storm sewer.
• Use bio-degradable soap when possible.
• Use a water softener to decrease lime-scale in piping when possible.
• Educate staff on proper waste disposal methods.
• Keep records of all sump maintenance form (pdf) and waste disposal.

Interceptors and sumps must be regularly maintained in order to function properly. The City of Airdrie suggests a record be kept of such maintenance, to ensure good business practices are being followed. Failing to maintain a grit interceptor or sump may result in fines and/or surcharges.

Sump/Grit Trap Maintenance Form (PDF)

There has been significant growth in the brewery and fermentation industry (home brewer, micro-breweries, cideries, distilleries and kombucha producers) across Alberta and in the City of Airdrie over the last few years. These operations create a wastewater that can exceed bylaw parameters that have nutrients that cannot be filtered out and must be treated properly, resulting in higher treatment costs.

Physical treatment of wastewater is a key step to reducing wastewater streams. Traditional physical treatment methods such as screening, settling, sedimentation, flotation and filtration can be applied to remove solids, consequently reducing COD and TSS. Screening and settling are the two most used methods. All these applications require some regular level of attention and maintenance.

SUMP/GRIT TRAP MAINTENANCE FORM (PDF)

Cleaning and Water Use

Manual scrubbing and using less environmentally harsh chemicals may be options to minimize fluctuating pH, especially since the fermentation process is very acidic. Daily testing of the operation’s effluent pH should be completed and recorded. If effluent from cleaning is outside of the acceptable bylaw limits, a neutralization or equalization tank may need to be added. If temperature exceedances are also common, this tank will have the added benefit of allowing process water to cool to an acceptable level prior to discharge to the wastewater system.

Clean-in-place (CIP) systems can also be used and are typically more efficient than manual cleaning. They use high temperatures and reduce water and chemical use by up to 50 per cent. Planning for a CIP system is best, as retrofitting a system may be cost prohibitive.

Water conservation methods:

• Using high pressure nozzle and hoses
• Dry clean before wet cleaning
• Install water efficient equipment and fixtures

Off-Spec Product and Spillage

Final product that does not meet your standards for consumption should never be released directly into the sanitary system because it likely contains a very high COD and unacceptable pH values. This would make it a restricted substance and may be subject to surcharges and fines. This would also apply to any spillage that may occur during the bottling process. 

During a spill it is important to act quickly to prevent wastewater from entering any nearby sanitary or storm drain as the effluent would have adverse effects on the environment. In the event of a spill into the storm or sanitary system, contact the City of Airdrie by calling 403.948.8871 and providing the following information:

• The address/location of the premise where the release into the storm or sanitary system occurred
• Contact details for someone on site
• Any other person(s) that may be affected by the release

Repair and maintenance facilities have the potential to release harmful substances including paints, oils, solvents, hydrocarbons, oil and grease. These substances may cause significant changes in wastewater temperature, pH and odour. Please take the following preventative measures to comply with the Sewer Bylaw:

• Install an oil/grease interceptor and dispose of harmful substances at appropriate facilities.
• Dispose of paint, metals and restricted chemicals using designated services.
• Educate staff on proper chemical storage and disposal.
• Install a sump/grit interceptor to separate debris from washed vehicles.
• Keep records of all sump maintenance form (pdf) and waste disposal.

SUMP/GRIT TRAP MAINTENANCE FORM (PDF)

Salons, spas and pet grooming facilities can release prohibited and restricted substances containing bleach, ammonia and phthalates into the sanitary sewer system. These products can alter pH, odour and temperature of effluent. They are difficult to treat and can harm public and private infrastructure as well as the environment. Please take the following preventative measures to comply with the Sewer Bylaw:

• Install a hair/sediment interceptor.
• Use mesh sink traps and put hair in the trash/organics bin.
• Use products that are non-hazardous and non-toxic when possible.
• Dispose of harmful/restricted chemicals using appropriate services.
• Use phthalate-free (fragrance–free) products when possible.
• Educate staff on proper chemical storage and disposal of waste.
• Keep records of all interceptor maintenance form (pdf) and waste disposal.

SUMP/GRIT TRAP MAINTENANCE FORM (PDF)

Amalgam used in dental procedures can cause damage to the environment and wastewater infrastructure if it is released into the sanitary sewer system. Amalgam contains mercury and when accumulated, can cause adverse effects. Please take the following preventative measures to comply with the Sewer Bylaw:

• Install amalgam separators on all fixtures that are ISO:11143 certified or meet ISO:11143 efficiency standard.
• Educate staff on proper disposal of amalgam.
• Keep records of all interceptor maintenance (pdf) and waste disposal.

Discharge of amalgam is outlined in the City of Airdrie Sewer Bylaw.

SUMP/GRIT TRAP MAINTENANCE FORM (PDF)