Water Quality Sampling Program Summary - 2022

prepared by Aquality Environmental Consulting Ltd.

SARDA Ag Research (SARDA) began a water quality monitoring program in 2011, with the assistance of Aquality Environmental Consulting Ltd (Aquality). Of the three sites selected, one is more pristine with little upstream agricultural activity (Little Smoky River), one primarily drains areas dominated by livestock-based agricultural activities (New Fish Creek), and one primarily drains areas dominated by cropland (Peavine Creek).

Preliminary sampling commenced in 2011, with more comprehensive data being collected annually in subsequent years. Semi-annual water sampling continued in 2022. In 2022, sampling occurred in the late fall (May 30) and again in the fall (October 31). Both sets of samples collected were analyzed for nutrients, bacteria, herbicides, pesticides, and metals.

The study area is located within the MD of Greenview and the MD of Smoky River. All sampling locations fall within the Smoky River watershed, which is itself part of the Peace River Basin. The area is located within the northern portion of the Dry Mixedwood natural subregion associated with the Peace River.

Climate conditions in 2022 were generally hotter and drier than the 30-year norm. Flows within the Little Smoky River (the only watercourse in the study with a gauging station present) were generally below normal except during elevated spring runoff and later season storm events.

The Province of Alberta released new water quality guidelines in 2018 (Government of Alberta, 2018), updating those previously available from 2014 Government of Alberta, 2014), though guidelines for the parameters investigated in the current study remained unchanged. Where possible, the newer guidelines will be used in this report.

Measured Parameters

Concentrations of Total phosphorus (TP) were highest and exceeded the 1999 guideline (0.05 mg/L) at Sites A and B in the spring but were below the guideline at all sites in the fall. Concentrations in 2022 were below historical averages both overall and at each site individually.

Dissolved phosphorus concentrations were highest at Site B and the lowest at Site C, which differs from the historical trend in which the highest oncentrations have generally been observed at Site A.

Concentrations of Total Nitrogen (TN) exceeded the 1999 guideline (1.0 mg/L) at Peavine Creek in both the spring and fall and were below the guideline for all the other samples. Concentrations at all sites were highest in the spring, in agreement with the historical pattern. Concentrations of TN had shown an increasing trend over time, dominated by extremely high concentrations at Peavine in 2016, 2018, and 2020, but the trend has weakened due to lower concentrations in the past two years, with the majority of samples falling below seasonal historical averages from 2021 onwards.

Dissolved fractions of nitrogen (nitrate, nitrite, and ammonia) have generally been a minor contributor to TN concentrations. This indicates that most of the nitrogen in the system is in particulate form, either bound to suspended sediment or in particulate organic matter. This continued to be the case observed in 2022, with an absence of the extraordinarily high concentrations of nitrate that have periodically been observed at Peavine Creek.

Total Suspended Solids (TSS) and turbidity measurements are related to the concentration of particulate matter suspended within the water column, generally due to erosion and sedimentation from upland sources, or erosion within channel. Samples collected from the present study show a very strong positive correlation between TSS and turbidity (linear regression r2 = 0.96).

Although there was substantial variation between sites from season to season, overall average TSS concentrations and turbidity measurements were comparable between sites on an annual basis, and below their historical averages over the course of the monitoring program. There continues to be no significant correlation between either turbidity and TSS and either annual precipitation or winter snowpack.

In 2022, total coliforms exceeded the guideline (1000 CFU/mL) in the spring at site A and were below the guideline for all other samples. Total coliform concentrations continue to show inconsistent patterns, with high degrees of variability both seasonally and between years. Historically, site A has exhibited the highest concentrations, with the overall average exceeding the guideline for irrigation (CCME, 2022), while averages for sites B and C have fallen below the guideline.

E. coli concentrations counts were higher in the spring than in the fall at all sites in 2022, and were below guidelines for all samples analyzed. Historically, site B has exhibited the highest overall average concentration, but averages for all sites fall below the guideline.

Samples were analyzed for one hundred different pesticides; however, no pesticides were detected in 2022. There have been no pesticide detections at any of the sampling locations since 2015, with a total of 13 detections from 2011 – 2015, indicating substantial improvement in these parameters.

Samples were analyzed for 34 different metals and ions, for both total and dissolved forms. In 2022, 5 metals exceeded the 2018 guidelines, including aluminum, chromium, iron, mercury, and zinc. Six total guideline exceedances were observed, of which 4 occurred at site B in the spring, and 2 occurred at site A in the fall. Historically, the greatest number of exceedances have occurred for zinc, chromium, lead, mercury, nickel, and iron. Over the entire course of the study, exceedances have been most frequent at site B, followed by site A, and then site C. The overall number of exceedances has varied substantially from year to year but has been generally trending upward, continuing to be primarily driven by the high number of exceedances at site B.

River Water Quality Index Site Ranking

In 2013, Aquality modified Alberta Environment and Parks’ (AEP) River Water Quality Index to include the parameters sampled by SARDA while keeping the same methodology and statistical formulas. The modified index considers the number of times a parameter exceeded guidelines and the magnitude of those exceedances, broken down across four categories of parameters:

• Bacteria,

• Metals,

• Nutrients and Related Variables, 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. The index has been updated annually to reflect any changes made to provincial guidelines. When changes have been made, results from the past sampling periods were updated with the new guidelines, allowing for direct comparisons between current and past years.

The water quality index was calculated by season for all sample sites. In 2022, the poorest water quality index value (78%) was observed at site A in the spring, while the best values (100%) were observed at the site B in the fall and site C in both the spring and fall. Overall average values for the year were similar to or greater than the historical averages for each site, and for all sites the WQI value in the spring was poorer than or equal to the value in the fall.

Water quality sub-indices for each of the four parameter groups (Bacteria, Metals, Nutrients & Related Variables, and Pesticides) show a generally similar pattern. Pesticides were not a problem at any of the sites, while Metals and Nutrients & Related Variables have had the greatest detrimental impact to overall water quality. The only exception to the seasonal pattern of improvement from spring to fall was for the metals subindex at site A, which fell from 100 to 56% over that period. This pattern matches that observed for TSS and turbidity, which also peaked in the fall at site A.

Seasonal Water Quality Index values, 2022

The ranking of the scores corresponds to their landscape position within the watershed, with Little Smoky the highest and Peavine Creek the lowest. This in turn relates to the degree of landscape development that has occurred within the catchment of each, with the greatest development lower and least development higher in the watershed. The spatial distribution of the landscape pattern in a watershed is often linked with the process of non-point source pollution.

Given that nutrient and metal exceedances are the primary drivers of impaired water quality within these systems, it is clear that particulates within the water column are a key underlying issue for aquatic ecosystem health. Particulate pollutants enter aquatic systems suspended in surface water runoff, from the erosion of banks of water courses, and from erosion of the bed of the watercourse itself. All of these processes occur naturally and contribute to the development and maintenance of the aquatic system. However, they can all be exacerbated through human activities that impact vegetation cover and the amount of exposed or erodible soils within the watershed, as well as factors that impact the volume and timing of surface water runoff.

dense riparian vegetation will assist in settling and act as a filter. For areas where particulate-based pollutants are a primary concern, mitigation should focus on the protection and restoration of riparian areas within areas carrying surface runoff into the watercourses from developed landscapes. In addition to a focus on headwater and ephemeral streams, this should also include areas of the landscape where historical ephemeral flows may have occurred, which now experience accelerated runoff due to grading, channelization, or wetland infilling.

Potential mitigations for erosion and sedimentation around channels include bank stabilization, riparian plantings and setbacks, erosion and sediment control in ditches feeding into watercourses (e.g. at watercourse crossings), and off-site watering of livestock. The restoration of natural flow patterns to channelized streams and the restoration of ditched or filled wetland areas is also likely to have substantial benefit, especially in areas of extensive historical recontouring. The restoration of these areas serves to slow flows and allow particulates to settle out of the water column.

Historical Water Quality Index Values, 2011 - 2022 Summary and Conclusions

In 2022, seasonal and spatial patterns water quality were generally comparable to historical trends; the overall Water Quality Index was comparable to historical values at site A and B, and higher (better) than historical values at site C. Throughout the entire course of the study to date, water quality has been highest at site C (Little Smoky River, 95.9% overall WQI score), followed by site B (New Fish Creek, 89.5% overall WQI score), then site A (Peavine Creek, 79.9% overall WQI score). The Bacteria and Pesticide subindex scores were 100% for all sites and seasons, largely in keeping with historical trends. There have been no pesticide detections at any of the sampling locations since 2015, with a total of 13 detections from 2011 – 2015, indicating substantial improvement in these parameters. Nutrients and metals continue to be the greatest impediments to water quality within all of these sites.

The correlation of water quality and landscape position, with poorer water quality generally observed at lower landscape positions in the watershed and in areas of higher development, suggests that human activities are having a substantial impact on the health of these aquatic ecosystems. Within the catchment upstream of site A, approximately 82 % of the land base is under agricultural development, compared to 3 % for site B and <0.1 % for site C. Road development is similarly higher upstream of site A compared to sites B and C (1.1 km/ km2 compared to 0.56 and 0.61 km/km2, respectively), as is the footprint of oil and gas development (1.0 % compared to 0.7 % and 0.6 %, respectively).

The primary driver of these patterns of poor water quality appears to be largely suspended sediments present due to in-channel erosion as well as sedimentation from surface runoff carrying soil into the streams. The majority of pollutants of concern including Total Phosphorus, E. coli, Total Coliforms, metals exceedances, and most total metal parameters continue to exhibit positive correlations with total suspended solids concentrations.

Particulate pollutants can be mitigated to an extent through the maintenance and restoration of riparian areas, as has been suggested in previous years, as

Mitigation of dissolved pollutants (e.g. nitrate and total dissolved phosphorus) requires that flows be slowed to allow infiltration and uptake by plants, breakdown by soil microbes, or immobilisation by adsorption onto soil particles. During the spring when vegetation is limited, the efficacy of removal of dissolved pollutants by riparian vegetation is substantially reduced; therefore management of dissolved pollutants by identifying sources and preventing application in the first place is generally more effective.

For areas where dissolved pollutants are a primary concern, the source of the pollutants needs to be identified prior to determining appropriate mitigations. Wetlands may be effective at retaining dissolved pollutants and preventing them from entering watercourses, when the source is through surface runoff and overland flow, such as application of soluble fertilizers or run-off from pastures or confined feeding operations. However, where dissolved pollutants are directly entering a watercourse through wastewater or stormwater releases via an outfall, then controls such as additional treatment or polishing wetlands are required to remove them. Further landscape studies can be undertaken to address these issues.