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Management of shellfish harvesting in areas next to wastewater treatment plants

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There are many shellfish harvest areas along the Canadian coastline, and some of these are next to wastewater treatment plants. When a plant discharges untreated or partially-treated sewage, the waters near the discharge can be affected by an increase in levels of microbiological contamination. Bivalve shellfish from these areas may cause serious illness or death if consumed by humans. As such, the impacts of these plants are examined and areas where shellfish can be harvested are identified.

Always look at the Check Before You Harvest map before harvesting, to get real-time information on openings and closures of harvesting areas.

Only commercial harvesters who have a Management of Contaminated Fisheries Regulations licence can harvest in conditionally restricted areas. These areas are not open for harvesting to the general public.

We may use conditional management plans to govern harvest areas next to wastewater treatment plants. We routinely monitor the waters in these areas to see if they meet the Canadian Shellfish Sanitation Program's harvesting standards.

Conditional management plans near wastewater treatment plants

A conditional management plan is an agreement between the owner or operator of a wastewater treatment plant system and federal authorities. They work together to ensure that the quality of the water next to the plant is acceptable for harvesting.

A conditional management plan sets roles and responsibilities of all signatory parties in:

These actions work to prevent harvesting from contaminated waters.

Plant operators must report the details of a discharge to federal authorities, who determine when the waters and shellfish in surrounding areas are safe for harvesting activities.

For plant systems under conditional management plans, the Wastewater Treatment Plant Reporting Tool allows plant operators to quickly and easily report any discharge of sewage.

Detection, notification, response

The detection, notification, response period is the time allowed for responsible parties to fulfill their conditional management plan roles when a plant system malfunction occurs. This covers the time from the detection of the sewage discharge to the closure of the area. During this period harvesters and processors undertake control measures to mitigate the risk of contaminated shellfish being harvested, processed or sold.

Harvesters and processors play an important role in ensuring that any bivalve shellfish sourced from areas near plants are safe to eat. When a sewage discharge is detected, the community receives an email notice that the harvesting areas next to the discharge point will close. Implementing control measures in response to receiving a notification is vital in protecting against contaminated bivalve shellfish entering the marketplace.

Shellfish harvesters and aquaculture licence holders

You must have a Management of Contaminated Fisheries Regulations licence to harvest in a conditionally restricted area next to a plant. All shellfish harvesting is prohibited when the status of an area is set to "closed" status". Upon receiving notification of a sewage discharge, you must treat the area as if it is already under closed status, and stop harvesting.

Shellfish processors

If you process and ship shellfish between provinces/territories or export shellfish, you must possess a Canadian Food Inspection Agency Safe Foods for Canadians licence. You must have specific preventive control measures if you receive shellfish from conditionally managed areas. Preventive controls must ensure that shellfish are not distributed before the detection, notification, response period has elapsed. Upon receiving notification of a sewage discharge, you must treat the area as if it is already under closed status, and take corrective actions according to your specific controls.

Informing harvesters and processors about discharge events

Anyone harvesting or processing bivalve shellfish must ensure that the area the shellfish is harvested in is classified and in "open" status.

The Wastewater Treatment Plant Reporting Tool emails subscribers if a harvesting area will be placed in "closed" status due to a discharge. This service is available to anyone who is interested in being notified of area closures due to sewage discharge that are managed by conditional management plans.

When harvesters and processors receive an email titled "NOTICE - WWTP Discharge", they must initiate control or corrective measures for the described impact zone. This maintains food safety while the official closure (a prohibition order) is drafted and invoked, which can take 1 business day.

If you are a harvester or processor, subscribe to the "WWTP Discharge" notification service by contacting

Please include your name, e-mail, and the name of the wastewater treatment plants from which you want to receive notifications.


The time line for completing each of the 3 components of the detection, notification, response time period can be affected by several variables.


The plant operator detects a discharge and reports the spill to authorities. Plant systems can detect discharges instantly, within several hours, or anywhere in between. Detection speed depends on the age of the facility and its discharge-detection technology.


Conditional management plans require plant operators to report a discharge incident as soon as it is detected. An email titled "Notice - WWTP discharge" is sent to all subscribers immediately when the incident report is entered into the Wastewater Treatment Plant Reporting Tool.


Federal authorities invoke an official prohibition order closure for the impacted area. This legally prohibits bivalve shellfish harvesting in the area until the water and shellfish return to Canadian Shellfish Sanitation Program quality standards. Generally, 1 business day is needed to invoke a closure.

Conditional management plans across Canada

Conditional management plans usually divide the managed area into several zones, and a discharge incident may not impact all of the zones in the area. Map and area descriptions can help harvesters and processors to identify the zones that are impacted when a plant discharge takes place.

This information shows how shellfish food safety is being managed next to wastewater treatment plants, as well as a timeline for preventive actions. This information helps to educate:

Areas managed by conditional management plans near wastewater treatment plants

British Columbia:

New Brunswick:

Nova Scotia:

Prince Edward Island:


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