Wastewater Systems Effluent Regulations 2017 Annual Report: Section 2

2.0 WSER Reporting

Owners or operators of wastewater systems are required to submit an identification report and regular effluent monitoring reports as well as combined sewer overflow reports (for those systems with combined sewers). The following sections provide more information on these reports and a summary of the data submitted to Environment and Climate Change Canada.

2.1 Identification Reports

Owners or operators of existing wastewater systems subject to the WSER were required to submit an identification report to Environment and Climate Change Canada (ECCC) by May 15, 2013. New wastewater systems must submit an identification report within 45 days after the wastewater system comes into operation. Identification reports include information on the system owner, type of treatment, operational details and location of discharge points.

This section provides a status of the number of identification reports submitted by the end of 2017 as well as a breakdown of wastewater systems by ownership and treatment type.

2.1.1 Summary for the Submission of Identification Reports

As of the end of 2017, 1,881 identification reports had been submitted out of an estimated total of 2,319 wastewater systems identified as being subject to the WSER. Table 1 presents the number of submitted identification reports and the estimated number of those missing by province and territory. This includes wastewater systems covered under the equivalency agreement with Yukon.

In 2017, Quebec had the highest number of missing identification reports. The low rate of submission of identification reports may be the result of the publication of a proposed equivalency agreement, which, when finalized, would result in the WSER not applying to the majority of wastewater systems in the province^{Footnote 5} .

Table 1. Identification reports submitted under the WSER and estimated number of systems who are missing an identification report by the end of 2017 by province and territory.

2.1.2 Overview of Wastewater Systems with Identification Reports

Table 2 shows the number of wastewater systems reporting by the end of 2017 by owner type as indicated in the identification reports. The vast majority of wastewater systems in Canada that are subject to the WSER are owned by municipalities and other local authorities, such as regional governments (87% of systems). Indigenous communities also own or operate a large number of wastewater systems, representing 9% of systems. The remaining systems are owned or operated by federal authorities or owners falling into the “other” category. Wastewater systems owned by private companies are classified in the “other” category. Private companies may own wastewater systems that serve municipalities, camps, or recreational areas.

Table 2. Identification reports submitted by owner type.

2.1.3 Wastewater Treatment Type

Based on information reported, wastewater systems were divided into three categories:

• No Treatment: Typically in the form of a pipe that extends into a waterbody and discharges continuously with no treatment. Wastewater systems with limited screening or grit removal are also included in this category.
• Lagoon: In-ground ponds where wastewater is held for a specified time, known as the hydraulic retention time, and undergoes physical and biological treatment. Lagoons can either discharge intermittently, typically once or twice a year, or on a continuous basis. Types of lagoons can vary and include facultative, aerobic, anaerobic and aerated lagoons.
• Mechanical: Treatment technologies, other than lagoons, that use mechanical components such as tanks, pumps, blowers, screens and grinders to treat wastewater. This category includes systems with primary level of treatment such as clarifiers as well as those with more advanced treatment such as activated sludge and rotating biological contactors.

Table 3 and Figure 1 summarize the number of wastewater systems by treatment types across Canada by province and territory. The most common type of wastewater system in Canada is lagoon (56%), followed by mechanical (33%), with the remaining systems (11%) depositing untreated effluent. Wastewater systems with no treatment are found in Newfoundland and Labrador, Nova Scotia, British Columbia and Quebec; some of which have transitional authorizations under the WSER.

Table 3. Summary of the number of wastewater systems by treatment type and by province and territory

Figure 1. Map of the wastewater systems across Canada by treatment type

2.2 Effluent Monitoring Report Summary

Effluent monitoring reports are submitted either annually or quarterly, depending on both the volume of effluent discharged by the wastewater system and whether the system discharges continuously or intermittently as prescribed in the WSER. The information found in the monitoring reports includes:

• total volume and number of days effluent was discharged;
• average concentrations of CBOD and suspended solids; and
• results of acute lethality tests, if applicable.

Of the 1,881 systems that submitted identification reports by the end of 2017, 1,556 of these systems submitted all effluent monitoring reports.

Table 4. Summary of status of effluent monitoring reports for 2017 by province and territory.

2.2.1 Carbonaceous Biochemical Oxygen Demand (CBOD) and Suspended Solid “SS” Test Results

Table 5 shows the number of systems broken down by province that exceeded the CBOD and/or suspended solid limits of 25 mg/L under the WSER along with the total number of systems that met the limits. Some systems exceeded both the limits for CBOD and suspended solids. Systems are labelled as exceeding the effluent quality limits if there is at least one reported exceedance in any of the reporting periods in the calendar year. Overall, 73% of wastewater systems who submitted a monitoring report met the WSER effluent quality limits during all periods reported in 2017.  

Figures 2 - 6 present the breakdown of systems that met and exceeded the effluent quality limits by treatment type. The majority of reported exceedances came from wastewater systems with no treatment followed by lagoons. For a more detailed breakdown, please see Supplementary Data Table 1 and Supplementary Data Table 2 in Annex 4.3.

Overall, wastewater systems had greater difficulties meeting suspended solids (SS) compared to CBOD with 352 systems exceeding SS and 243 systems exceeding CBOD. The larger number of SS exceedances can largely be attributed to lagoon systems. A total of 121 lagoon systems reported exceedances of SS compared to 39 which reported exceedances of CBOD. 

Wastewater systems that received transitional authorizations under the WSER are not included in the effluent monitoring statistics. These systems are not required to achieve the WSER effluent quality limits until the deadline set in the transitional authorizations (please refer to section 3.1).

Table 5. Summary of CBOD and SS results in 2017, by province and territory.

*This represents the total number of systems that had either CBOD or SS exceedances. Some systems had both CBOD and SS exceedances.

Figure 2. Summary of CBOD and SS results in 2017 for wastewater systems under the WSER by treatment type.

Figure 3. Map of systems meeting the CBOD limits in 2017 for wastewater systems in western Canada

Figure 4. Map of systems meeting CBOD limits in 2017 for wastewater systems in eastern Canada

Figure 5. Map of systems meeting SS limits in 2017 for wastewater systems in western Canada

Figure 6. Map of systems meeting SS limits in 2017 for wastewater systems in eastern Canada

2.2.2 Acute Lethality Testing Results

The WSER require that wastewater systems discharge an effluent that is not acutely lethal. For the purposes of the WSER, “acute lethality” means that the effluent at 100% concentration kills more than 50% of the rainbow trout subjected to it during a 96-hour period^{Footnote 6} .

Under the WSER, owners or operators of wastewater systems discharging annual average daily effluent volumes greater than 2,500 m³ are required to determine and report on the acute lethality of the effluent. Table 6 and Figure 7 summarize the results of the acute lethality tests performed in 2017. Figure 8 and 9 present a summary of acute lethality test results across Canada.

A total of 474 wastewater systems tested for acute lethality in 2017, with 90% of systems passing all acute lethality tests. Of the systems reporting an acute lethality test failure, 68% were lagoon systems, 26% were mechanical systems, and the remaining 6% came from systems with no treatment. For a more detailed breakdown of acute lethality test results by province please see Supplementary Data Table 3 in the Annex section 4.3.

Table 6. Summary of reported acute lethality test results, by province

* – Yukon is not required to submit acute lethality data under the equivalency agreement

Figure 7. Reported acute lethality test results reported under the WSER by treatment type in 2017

Figure 8. Map of the acute lethality results in 2017 for wastewater systems in western Canada

Figure 9. Map of the acute lethality results in 2017 for wastewater systems in eastern Canada

2.2.3 Total Effluent Volumes

Wastewater systems are required to monitor and report their effluent flows at the final discharge point under the WSER. Figure 10 demonstrates the total reported effluent volume discharged via the final discharge point, by province and territory. These volumes do not include discharges of wastewater from combined sewer overflow points.

A total volume of 5.68 billion m³ of effluent was reported as being discharged from the final discharge point. Ontario reported the highest volume of effluent at 2.06 billion m³ (36%). Quebec reported the second highest volume at 1.88 billion m³ (33%) followed by British Columbia at 659 million m³ (12%) and Alberta at 487 million m³ (9%). The remaining provinces and Yukon each deposit less than 5% of the total effluent deposited.

Figure 10. Total reported effluent volume (million m³) by province and territory.

2.2.4 Effluent Volumes Discharged by Treatment Level

Table 7 shows the volume effluent discharged from the final discharge point of wastewater systems in 2017 broken down by effluent quality for each province. Wastewater effluent is categorized as either undergoing “No Treatment”, being “Undertreated”, or “Meets WSER” effluent quality limits as defined below:

• No Treatment: Effluent deposited from a wastewater system with no treatment process. Wastewater systems limited to screening or grit removal are included in this category.
• Undertreated: Effluent deposited from a wastewater system with treatment processes in place but did not meet the WSER effluent quality limits for CBOD and suspended solids.
• Meets WSER: Effluent deposited from a wastewater system with treatment processes in place and met the WSER effluent quality limits for CBOD and SS. This would indicate a secondary level of treatment.

Overall, 73% of the reported total volume of effluent that was deposited across Canada met the WSER effluent quality limits.

Undertreated effluent represents 26% of the reporting effluent volume deposited.

Untreated wastewater represent 1% of the total effluent deposited in Canada. Undertreated and untreated effluent is mainly discharged from coastal areas or large water bodies in British Columbia, Newfoundland and Labrador, Nova Scotia, and Quebec. Figure 11 shows wastewater systems based on their level of treatment across Canada including those that are untreated, undertreated, secondary (meet WSER effluent quality limits) and have advanced treatment (treated beyond a secondary level of treatment).

Figure 11. Map of the wastewater systems across Canada by treatment level

Table 7. Summary of effluent deposited by treatment level, by province in millions m³ for the year 2017.

2.3 Combined Sewer Overflow Reports

Many older municipalities in Canada have combined sewers that collect both storm water and wastewater. Combined sewers are designed to discharge untreated wastewater when the volume collected exceeds the capacity of the system due to heavy rainfall or snowmelt. The WSER require owners or operators of wastewater systems with combined sewers to submit an annual report on the total volume and the number of days wastewater is discharged per month via combined sewer overflow (CSO) points as a result of precipitation.

2.3.1 Wastewater Systems with CSO Points

Table 8 presents the number of wastewater systems in each province that have at least one CSO point. Figure 12 presents the 179 systems that reported having at least one CSO point as well as volumes. Approximately half of the systems that identified CSO points in Canada are located in Quebec. Ontario also has a significant number of systems with CSO points (23%).

Table 8. Number of combined sewer systems, by province 

A complete list of the 179 wastewater systems that reported having a combined sewer system can be found in Annex 4.2.

Figure 12. Map of the combined sewer systems and their volumes of effluent in 2017 for wastewater systems in Canada

2.3.2 CSO Points and Volume by Province and Territory

Combined sewer systems have multiple points at which the combined sewer can overflow, discharging untreated wastewater. Systems must identify each individual point where a CSO can occur in their identification report, and must report annual volumes from each of these points.

Figure 13 presents the total reported number of CSO points in each province and the total report volume of untreated wastewater discharged from these points in 2017. There are a total of 2,091 CSO points in Canada. As Quebec has the majority of combined sewer systems, it also has the most CSO points in Canada (48%) followed by Ontario (32%), New Brunswick (7%), Nova Scotia (5%), Manitoba (4%) and British Columbia (2%). The total reported volume nationally is 167 million m³. Of the reported volumes, British Columbia is responsible for the highest volume of untreated effluent discharged from CSO points (42%). Quebec and Nova Scotia reported 16% and 14% of the volume discharged by CSOs, respectively. The remaining volume of effluent discharged by CSOs come from Alberta, Manitoba, Ontario, and New Brunswick, each discharging less than 13% of the national total.

Figure 13. Number of CSO points and total volume of CSO effluent discharged by province and territory.