2.0 Jock River-Barrhaven Catchment: Surface Water Quality Conditions

Surface water quality conditions in the Jock River-Barrhaven catchment are monitored by the City of Ottawa’s Baseline Water Quality Monitoring Program. This program provides information on the condition of Ottawa’s surface water resources; data is collected for multiple parameters including nutrients (total phosphorus, total Kjeldahl nitrogen and ammonia), E. coli, metals (like aluminum and copper) and additional chemical/physical parameters (such as alkalinity, chlorides, pH and total suspended solids). The locations of monitoring sites are shown in Figure 2 and Table 1.

2.1 Jock River Water Quality Rating

There are two monitored water quality sites on the Jock River in the Barrhaven Catchment (JR-01 and JR-02), the RVCA's water quality rating for these are “Fair” (Table 1) as determined by the Canadian Council of Ministers of the Environment (CCME) Water Quality Index^[1]. A “Fair” rating indicates that water quality is usually protected but is occasionally threatened or impaired; conditions sometimes depart from natural or desirable levels. Each parameter is evaluated against established guidelines to determine water quality conditions. Those parameters that frequently exceed guidelines are presented below. Analysis of the data has been broken into two periods; 2004 to 2009 and 2010 to 2015 to examine if conditions have changed between these periods. Table 1 shows the overall rating for the monitored surface water quality sites within the Jock River-Barrhaven catchment and Table 2 outlines the Water Quality Index (WQI) scores and their corresponding ratings.

Both sites had only small changes between the two reporting periods, with minor improvements in the water quality score.  The scores at these sites are largely influenced by frequent high nutrient concentrations and occasional metal exceedances. For more information on the CCME WQI, please see the Jock River Subwatershed Report.  For more information on the CCME WQI, please see the Jock River Subwatershed Report.  

2.2 Nutrients

Total phosphorus (TP) is used as a primary indicator of excessive nutrient loading and may contribute to abundant aquatic vegetation growth and depleted dissolved oxygen levels. The Provincial Water Quality Objective (PWQO) is used as the TP Guideline and states that in streams concentrations greater than 0.030 mg/l indicate an excessive amount of TP.

Total Kjeldahl nitrogen (TKN) and ammonia (NH₃) are used as secondary indicators of nutrient loading. RVCA uses a guideline of 0.500 mg/l to assess TKN^[2] and the PWQO of 0.020 mg/l to assess NH₃ concentrations in the Jock River.

Tables 3, 4 and 5 summarize average nutrient concentrations at monitored sites within the Jock River-Barrhaven catchment and show the proportion of results that meet the guidelines.

Monitoring Site JR-01

The majority of samples at site JR-01 were above the TP guideline from 2004-2009; however the proportion of exceedances decreased in the 2010-2015 monitoring period (Figures 3 and 4). The number of samples below the guideline improved from 38 percent in 2004-2009 to 48 percent in 2010-2015, and the average TP concentrations decreased slightly from 0.037 mg/l (2004–2009) to 0.033 mg/l (2010–2015) as shown in Table 3.

TKN concentrations show that the bulk of results exceeded the guideline (Figures 5 and 6); there were few samples (eight percent) below the guideline in the 2004-2009 period and this declined to only two percent in the 2010-2015 period. The average concentration was generally elevated and increased from 0.698 mg/l to 0.714 mg/l (Table 4).

In the 2004-2009 reporting period 56% of NH₃ results were below the guideline with an average concentration of 0.034 mg/l (Figure 7, Table 5). The percentage of results below the guideline declined to 41% in the 2010-2015 period, though the average concentration decreased to 0.028 mg/l (Figure 8, Table 5).  The overall reduction in NH₃ concentrations may be influenced by the lack of samples in March during the 2010-2015 period (Figure 8).  In the 2004-2009 period samples in March had the greatest concentrations (Figure 7), likely influenced by the impact of meltwater conditions which increases runoff and potential loadings to the river.

Monitoring Site JR-02

Elevated TP results were a common occurrence at site JR-02 and remained consistent between the two monitoring periods; 41 percent of samples were below the guideline in the 2004-2009 period (Figure 3); this remained consistent at 42 percent of samples in the 2010-2015 period (Figure 4). The average TP concentration was largely unchanged decreasing only slightly from 0.038 mg/l (2004-2009) to 0.036 mg/l (2010-2015) as shown in Table 3.

The bulk of TKN results have exceeded the guideline (Figure 5 and 6), with six percent of samples below the guideline in the 2004-2009 period, decreasing to no samples below the guideline in 2010-2015. The average concentration was elevated and increased from 0.706 mg/l to 0.714 mg/l (Table 4).

The results for NH₃ indicate that exceedances were common. Fifty-four percent of results were below the guideline in 2004-2009 (Figure 7); this decreased to 35 percent in the 2010-2015 reporting period (Figure 8). The average NH₃ concentration decreased marginally from 0.037 mg/l to 0.034 mg/l (Table 5). 

Figure 3 Total phosphorous concentrations in the Jock River, 2004-2009

Figure 4 Total phosphorous concentrations in the Jock River, 2010-2015

Figure 5 Total Kjeldahl nitrogen concentrations in the Jock River, 2004-2009

Figure 6 Total Kjeldahl nitrogen concentrations in the Jock River, 2010-2015

Figure 7 Ammonia concentrations in the Jock River, 2004-2009

Figure 8 Ammonia concentrations in the Jock River, 2010-2015

Summary

Nutrient enrichment has previously been identified as a feature in this reach of the Jock River^[3].  Overall, average nutrient concentrations have remained consistent through the monitoring periods, with few changes in some sites or parameters. All parameters (total phosphorus, total Kjeldahl nitrogen and ammonia) exceed their respective guidelines reguarly.  Elevated nutrients may result in nutrient loading downstream and to the Rideau River. High nutrient concentrations can help stimulate the growth of algae blooms and other aquatic vegetation in a waterbody and deplete oxygen levels as the vegetation dies off. Best management practices such as minimizing storm water runoff, enhanced shoreline buffers, minimizing/discontinuing the use of fertilizers and restricting livestock access in upstream agricultural areas can help to reduce nutrient enrichment in Jock River and subsequent impacts on the Rideau River.  

2.3 Escherichia coli

Escherichia coli (E. coli) is used as an indicator of bacterial pollution from human or animal waste; in elevated concentrations it can pose a risk to human health. The PWQO of 100 colony forming units/100 millilitres (CFU/100 ml) is used. E. coli counts greater than this guideline indicate that bacterial contamination may be a problem within a waterbody.

Table 6 summarizes the geometric mean^[4] for the monitored sites on the Jock River within the Barrhaven catchment and shows the proportion of samples that meet the E. coli guideline of 100 CFU/100 ml. The results of the geometric mean with respect to the guideline for the two periods, 2004-2009 and 2010-2015, are shown in Figures 9 and 10 respectively.

Monitoring Site JR-01

E. coli counts at site JR-01 indicate little change with regard to bacterial contamination. The proportion of samples below the guideline rose marginally from 78 percent (Figure 9) to 80 percent (Figure 10). The count at the geometric mean increased from 39 CFU/100ml in 2004-2009 to 46 CFU/100ml from 2010-2015 (Table 6). Although the count at the geometric mean increased, the geometric mean is below the guideline and the majority of samples are below the PWQO for E. coli.  

Monitoring Site JR-02

Elevated E. coli counts at site JR-02 occurred occasionally. The proportion of samples below the guideline decreased from 83 percent (Figure 9) from 2004-2009 to 73 percent (Figure 10) from 2010-2015. The count at the geometric mean also increased slightly between the two monitoring periods from 43 CFU/100ml to 47 CFU/100ml (Table 6).  Although E. coli counts did increase marginally the geometric mean is well below the E. coli PWQO. 

Figure 9 Geometric mean of E. coli results in the Jock River, 2004-2009

Figure 10 Geometric mean of E. coli results in the Jock River, 2010-2015

Summary

Bacterial contamination does not appear to be a significant concern in this reach of the Jock River.  Both sites (JR-01 and JR-02) have occasional exceedances and counts at the geometric mean below the guideline of 100 CFU/100ml. Best management practices such as enhancing shoreline buffers, limiting livestock access and minimizing runoff in both rural and urban areas can help to protect this reach of the Jock River into the future.

2.4 Metals

Of the metals routinely monitored in the Jock River (Barrhaven Catchment) aluminum (Al) and copper (Cu) occasionally reported concentrations above their respective PWQOs. For Al, the PWQO is 0.075 mg/l and for Cu it is 0.005 mg/l.  In elevated concentrations, these metals can have toxic effects on sensitive aquatic species.

Tables 7 and 8 summarize metal concentrations at sites JR-01 and JR-02 as well as show the proportion of samples that meet guidelines. Figures 11 to 14 show metal concentrations with respect to the guidelines for the two periods of interest, 2004–2009 and 2010–2015. 

Monitoring Site JR-01

The average Al concentrations in site JR-01 exceeded the guideline. Most samples (66 percent) were below the guideline (Figure 11) from 2004-2009, this declined marginally to 64 percent (Figure 12) of results reporting below the guideline from 2010-2015. The average concentration increased from 0.085 mg/l to 0.094 mg/l (Table 7).

Copper concentrations occasionally exceeded the PWQO, with 75 percent of samples below the guideline in 2004-2009 (Figure 12). The Cu concentrations increased to 84 percent of samples being below the guideline in 2010-2015 (Figure 14). The average concentration of copper marginally decreased during the two reporting periods from 0.0036 mg/l to 0.0026 mg/l (Table 8).  The lack of sampling in March for the 2010-2015 period (Figure 14) may account for this apparent decrease, as elevated results were observed in March during the 2004-2009 period (Figure 13). 

Monitoring Site JR-02

Results from JR-02 provide evidence of increasing Al concentrations between the two reporting periods. Seventy-one percent of samples were below the guideline in the 2004-2009 period (Figure 11). This decreased to 59 percent of samples in the 2010-2015 period (Figure 12). The average concentration of Al was 0.075 mg/l from 2004-2009 and increased to 0.099 mg/l from 2010-2015 (Table 7).

Copper concentrations have occasionally exceeded the guidelines but did not show marked change between the two reporting periods. In the 2004-2009 period 76 percent of samples were below the guideline (Figure 13) and rose slightly to 78 percent of samples in the 2010-2015 period (Figure 14). The average concentrations (Table 8) increased marginally from 0.0034 mg/l (2004-2009) to 0.0037 mg/l (2010-2015). 

Figure 11 Average aluminum concentrations in the Jock River, 2004-2009

Figure 12 Average aluminum concentrations in the Jock River, 2010-2015

Figure 13 Average copper concentrations in the Jock River, 2004-2009

Figure 14 Average copper concentrations in the Jock River, 2010-2015

Summary

In the Barrhaven catchment aluminum concentrations have increased at both sites JR-01 and JR-02 while copper concentrations have remained consistent.  Most increases in concentrations are observed during the spring likely due to increased runoff amounts from melt conditions; runoff picks up pollutants from farms, yards, roads and parking lots^[5].  As there has been increased urbanization in this area it is likely that runoff from hardened surfaces (roadways, parking lots, etc.) is influencing metal concentrations.  Continued efforts should be made to identify pollution sources and implement best management practices to reduce any inputs such as storm water runoff to improve overall stream health and lessen downstream impacts.