Water Quality Sampling Program Results, 2019

2019 Water Quality Sampling Program Results, 2019

SARDA Ag Research began a water quality monitoring program in 2011, with the help of Aquality Environmental Consulting Ltd (Aquality). Surface water samples were taken from three sites in SARDA’s research area: Peavine Creek, New Fish Creek, and the Little Smoky River. Sample locations, chosen by SARDA, were based on their proximity to agricultural lands, use as drinking water intakes, and their likelihood of exposure to terrestrial inputs.

Semi-annual sampling continued in 2019. Sampling occurred once in the late spring to early summer after the spraying of pre-emergent herbicides on croplands, and again in late summer to early fall following harvest. Water samples were analyzed for nutrients, bacteria, pesticides, and metals.

In 2019, samples were collected on July 22 for the spring/early summer period and October 16 for the fall period.

Water Quality Guidelines

The Province of Alberta released new water quality guidelines in 2018, updating those previously available from 2014, though no guidelines for the parameters investigated here were changed. Where possible, the newer guidelines will be used in this report. For some parameters (nitrogen and phosphorus in particular), the updated document outlines an approach for calculating site-specific guidelines but does not provide a fixed guideline for comparison. Because site-specific guidelines have not been determined for the sites in the present study, the previous 1999 guidelines will be used for these parameters.

Results

Phosphorus

Concentrations of Total phosphorus (TP) were highest at all sites in the spring, and exceeded the guideline (0.05 mg/L) at New Fish Creek and Little Smoky River during the spring. Peavine Creek had the lowest average TP concentration in 2019, which contrasts with the historical pattern. Historically, concentrations of TP have been highest at Peavine and lowest at Little Smoky.

Sampling locations for the SARDA Water Quality Monitoring Program

Dissolved phosphorus concentration was the highest in Peavine Creek and the lowest in Little Smoky River, which generally agrees with the historical pattern (Figure 1 and Figure 2). Overall, dissolved fractions make up a minor component of the total phosphorus concentration. The red line indicates the Alberta surface water quality guideline for the protecton of aquatic life (0.05 mg/L).

Figure 1. Historical Total Phosphorus (TP) concentrations spring and fall 2011 – 2019.

Figure 2. Historical Total Dissolved Phosphorus (TDP) concentrations, spring and fall, 2011 – 2019.

Nitrogen

Concentrations of Total Nitrogen (TN) exceeded the guideline (1.0 mg/L) at all sites in the spring, but only at Peavine in the fall. Concentrations at all sites were highest in the spring, in agreement with the historical pattern.

Dissolved fractions of nitrogen (nitrate, nitrite, and ammonia) have generally been a minor contributor to TN concentrations, indicating that most of the nitrogen in the system is in particulate form, either bound to suspended sediment or in particulate organic matter.

Overall, there has been a signifi cant increasing trend in TN concentrations. Th is trend is strongest at Peavine, but this may be due to the exceptionally high measured value of TN which occurred in 2018 (Figure 3). However, the overall number of exceedances has been higher since 2015 than prior to that time, with 43% of samples in exceedance from 2015-2019 compared to just 29% from 2011-2014.

Figure 3. Historical Total Nitrogen (TN) concentrations, spring and fall, 2011 – 2019

Figure 4. Historical total coliform concentrations, spring and fall, 2011 – 2019

Bacteria

In 2019, total coliform concentrations were highest in the spring at all sites, and exceeded the guideline (1000 CFU/100 mL) at New Fish Creek and Little Smoky. Concentrations were lower during the fall, with no exceedances during that sampling period. Total coliform concentrations have shown inconsistent trends between sites, with annual concentrations increasing at New Fish Creek and Little Smoky but falling at Peavine (Figure 4).

E. coli concentrations were higher in the spring than in the fall at all sites in 2019, but were below guidelines in both seasons. New Fish Creek had the highest concentrations during the spring, but Little Smoky had the highest concentrations in the fall. No clear historical trend exists at any of the sites, with E. coli concentrations showing orderof-magnitude variability between years at all sites (Figure 5).

Pesticides

Samples were analyzed for a total of 41 diff erent pesticides; however, no pesticides were detected in 2019. Th ere have been no pesticide detections at any of the sampling locations since 2015, with a total of 13 detections from 2011 – 2015, indicating improvement in these parameters.

Figure 5. Historical E. coli concentrations, spring and fall, 2011 – 2019.

New Fish Creek Sample Site on the Little Smoky River

Metals

Samples were analyzed for 34 diff erent metals, for both total and dissolved forms. Of these, four metals exceeded guidelines for 2019, including cadmium, chromium, lead, and zinc. Exceedances of cadmium, chromium and lead were found at New Fish Creek in spring, whereas Little Smoky had exceedances of cadmium and chromium during spring. Peavine Creek had exceedances of zinc for both seasons.

Historically, New Fish Creek has had the highest total number of exceedances of metals (n=21), followed by Peavine Creek (n=15) and the Little Smoky River (n=11). Th e greatest number of exceedances have been for zinc (n=13), lead (n=9), and mercury and chromium (n=7 each), which together accounted for more than 76% of the total metals exceedances that have been detected over the course of the monitoring program. Aluminum was previously reported as having had numerous exceedances, but current guidelines for aluminum are determined against dissolved forms (Alberta Environment & Sustainable Resource Development, 2018), and previous exceedances had only been noted for total forms of aluminum.

Water Quality Index Site Ranking

Aquality developed a modified version of Alberta Environment and Parks’ (AEP) River Water Quality Index in 2013. Th e index was modifi ed to include all parameters sampled by SARDA; however, the methodology and statistical formula used to analyze the data remained the same. Th e index considers the number of times a parameter exceeded guidelines and the magnitude of those exceedances, broken down across four categories of parameters: • Nutrients and Related Variables, • Bacteria, • Metals, and • Pesticides

The results from the sub-indices are averaged to provide an overall water quality index score for each site, with 100 being the best water quality and 0 being the poorest. From these percentages, we can obtain a water quality rating for each site from excellent to poor.

In 2017 the AEP’s water quality tolerance parameters were updated to refl ect changes in provincial water quality guidelines. The index was, therefore, subsequently updated to reflect these changes. The results from the past sampling periods were updated with the new changes, allowing for parameters to be comparable with the old data.

River water quality rating categories.

The water quality index was calculated by season for all sample sites In 2019, the poorest water quality rating (60%)was observed at New Fish Creek in the spring, while the best water quality ratings (100%) were observed at the Little Smoky River and New Fish Creek in the fall. All other sample locations were considered to be Good in 2019. The table below shows the last 3 years of sample results. Scores are almost invariably poorer in the spring than the fall sampling period. Little Smoky has historically had the best scores, followed by New Fish Creek and then Peavine.

Water quality based on nutrient levels, bacteria contamination, metals content and pesticide residues are available in the full report accessible on SARDA’s home page at www.sarda.ca .

Summary and Conclusions

SARDA Ag Research has been monitoring water quality at three locations since 2011. Th e parameters assessed followed Alberta Environment & Parks Guidelines for river water quality and included nutrients, bacteria, metals and pesticides. Th is program has assisted in determining the most serious impediments to water quality in Peavine Creek, Fish Creek, and the Little Smoky River.

In 2019, nitrogen exceed guidelines at all sites in the spring but only at Peavine in the fall, while the only exceedances for phosphorus were at Fish Creek and Little Smoky River in the spring. Coliforms exceeded guidelines at Fish Creek and Little Smoky River in the spring but were at negligible concentrations in the fall; E. coli concentrations were highest in the spring at all sites, but remained below guidelines during both sampling events. No pesticides have been detected since 2015 at any of the sampling locations. Th e majority of metals exceedances in 2019 occurred during the spring, and were most common at Fish Creek. Cadmium, Chromium, and Zinc were the metals with the greatest number of exceedances, with two exceedances per metal.

Values for the River Water Quality Index in 2019 were generally in line with results from previous years, with nutrients, bacteria and metals the most impaired parameter groups. However, in 2019, New Fish Creek had the lowest overall scores, whereas historically the poorest scores were found at Peavine Creek. The highest scores in 2019 were at the Little Smoky River, which agrees with the historical trends.