2.0 Kings Creek Catchment: Surface Water Quality Conditions

Surface water quality conditions in the Kings Creek catchment are monitored by the City of Ottawa 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 Kings Creek Water Quality Rating

The RVCA's water quality rating for the Kings Creek site CK75-01 is “Good” (Table 1) as determined by the Canadian Council of Ministers of the Environment (CCME) Water Quality Index. A “Good” rating indicates that water quality is protected with only a minor degree of threat or impairment; conditions rarely depart from natural or desirable levels. Each parameter is evaluated against established guidelines to determine water quality conditions. Those parameters that are more likely to exceed guidelines are presented below. Table 1 shows the overall rating for the monitored surface water quality site within the Kings Creek catchment and Table 2 outlines the Water Quality Index (WQI) scores and their corresponding ratings.

There is one monitored water quality site on Kings Creek within the Kings Creek Catchment (CK75-01, Figure 2).  Due to limited data availability, only data for the 2010-2015 period has been assessed.  The water quality scores at this site is “Good” (Table 1), this score is largely due to few parameters that exceed their respective guideline. 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^[1] and the PWQO of 0.020 mg/l to assess NH₃ concentrations in Kings Creek.

Tables 3, 4 and 5 summarize average nutrient concentrations at the monitored site within the Kings Creek Catchment and show the proportion of results that meet the guidelines.

Monitoring Site CK75-01

Elevated TP results were a rare occurrence at site CK75-01. Ninety-eight percent of samples were below the guideline in the 2010-2015 period (Figure 3). The average TP concentration was also well below the guideline at 0.015 mg/l (Table 3).

The bulk of TKN results have exceeded the guideline (Figure 4), with 17 percent of samples below the guideline in the 2010-2015. The average concentration was elevated and exceeded the guideline at 0.645 mg/l (Table 4).

The results for NH₃ showed very few exceedances occurred. Ninety-eight percent of results were below the guideline in the 2010-2015 reporting period (Figure 5). The average NH₃ was well below the PWQO of 0.004 mg/l (Table 5).

Summary

Nutrient enrichment is not a significant feature at the monitored site on Kings Creek. Overall, average TP and NH₃ concentrations are well below the guideline, while regular TKN exceedances were observed.  The elevated TKN concentrations coupled with low NH₃ and TP results provide evidence that nutrient environment may be a natural feature in this part of the creek.  Upstream of CK75-01 there is limited development and large wetland areas which likely contribute to naturally high levels of organic nutrients. Best management practices such as minimizing storm water runoff, enhanced shoreline buffers, preventing the use of fertilizers and restricting livestock access should all be employed wherever possible to prevent unnecessary nutrient loading to downstream reaches and protect the “Good” water quality in this area.

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^[2] for the monitored site on Kings Creek within this 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 2010-2015 period is shown in Figure 6.

Monitoring Site CK75-01

E. coli counts at site CK75-01 were occasionally elevated. These exceedances generally occur in the mid-summer months where increased temperature would favour bacterial growth. Most samples (73 percent) are below the guideline in the 2010-2015 period (Figure 6). The count at the geometric was minimal at 42 CFU/100ml (Table 6).

Summary

Bacterial contamination does not appear to be a significant concern in this reach of Kings Creek. As previously noted; best management practices such as enhancing shoreline buffers, restricting livestock access and minimizing storm water runoff should be employed wherever possible to help protect and enhance water quality conditions in Kings Creek.