Chemical, physical, and biological data are summarized in Tables 1 and 2 with raw data listed in Appendices 1 and 2. Tables 1 and 2 also include information on the number of exceedences of water quality objectives (Manitoba surface water quality objectives, Williamson D.A. 1988). Averages and ranges for conductivity, total suspended solids, fecal coliform bacteria, un-ionized ammonia, phosphorus, and dissolved oxygen saturation levels are illustrated in Figures 2 through 7. Table 3 summarizes information on significant differences in concentrations between upstream and downstream sites on Boggy Creek and the Whitemud River.

pH

The pH never exceeded the water quality objectives of 6.5 and 9.0 which are recommended for the protection of aquatic life (Tables 1 and 2). There was a significant decrease in pH between the Gladstone and Westbourne sites on the Whitemud River. This was probably due to reduced activity of algae since there was also a significant decrease in chlorophyll a between these sites.

Conductivity and Total Dissolved Solids

Conductivity is a measure of the dissolved salts in the water and is closely related to total dissolved solids. The highest conductivities were observed in the Brookdale drain with one exceedence of the water quality objective of 1000 S/cm2 (Tables 1, and 2, and Appendix 2). Conductivities in Spring Creek were also relatively high and reached 1000 S/cm2 on one occasion. As indicated in Figure 2, the sampling site on the Brookdale drain was the only location where the conductivity exceeded the objective. It is not possible, at present, to identify a specific source of the relatively high total dissolved solids at these locations. However, it is likely that this is the result of the intrusion of saline groundwater.

Conductivity and total dissolved solids increased significantly between Boggy Creek and Westbourne (Table 3), possibly as a result of the intrusion of saline groundwater between these two sites.

Total Suspended Solids, and Turbidity

The objective for total suspended solids (TSS) is 25 mg/L. This was exceeded in four of eight samples in the Whitemud River at Arden Ridge site (Table 1, Appendix 1, and Figure 3). There were exceedences of the objective in one or two samples at each of seven other sites. The only sites where there were no exceedences of this objective were in the Brookdale Drain and the Whitemud River at Westbourne. Turbidity is a reflection of suspended solids. There were no significant differences in suspended solids or turbidity in river sites between the Boggy Creek site and the Whitemud River at Westbourne.

Fecal Coliform Bacteria

At most sites fecal coliform bacteria were less than the water quality objective for recreational waters of 200 fecal coliform bacteria per 100 mL of water (Table 2). However, at the Stony Creek site all four samples exceeded of the objective of 200 fecal coliform bacteria per 100 mL of water (Appendix 2 and Figure 4). Exceedences of the objective for individual samples occurred at three other sites. At the Boggy Creek site at Neepawa, two of 14 samples exceeded the objective. At the sites on the Big Grass Drain and Spring Creek exceedences of the objective occurred in one of seven, and one of six samples, respectively.

Fecal coliform bacteria counts at most sites appear to be relatively normal with the occasionally high value which may be due to local contributions, possibly from the activity of wildlife such as beavers, and waterfowl, or swallows nesting under bridges. However, bacteria counts at the Stony Creek site appear to be unusually high and this warrants further investigation.

Nutrients

Nutrients include a number of nitrogen compounds and phosphorus. Samples collected were analyzed for total Kjeldahl nitrogen, total ammonia-ammonium nitrogen, and nitrate-nitrite nitrogen as well as total and dissolved phosphorus. Both nitrogen and phosphorus are required for plant growth. Nitrogen is usually relatively abundant while phosphorus may be a limiting factor in the growth of rooted aquatic weeds and algae. An examination of all the nitrogen values (Tables 1, and 2, and Appendices 1 and 2) indicated no significant changes between sites immediately upstream and downstream of one another (Table 3). However, there were significant decreases in the ammonia-ammonium concentrations between the most upstream and down stream sites on Boggy Creek at Neepawa and the Whitemud River at Westbourne, respectively. There were significant increases in dissolved phosphorus between the Boggy Creek site and the Whitemud River site at Arden. There were also significant decreases in total and dissolved phosphorus between the Whitemud River sites at Arden Ridge at PTH 16, and Gladstone and the sites at Gladstone, and Westbourne, respectively (Table 3).

Un-ionized ammonia is of concern with respect to potential effects on fish and other aquatic life. The un-ionized ammonia objective varies with temperature and pH. There was only one exceedence of the objective and this occurred at the site on the Whitemud River at Arden on June 10, 1997 (Table 1, Appendix 1, and Figure 5). This was unusual since concentration of un-ionized ammonia at the downstream Arden Ridge site was similar at the upstream Boggy Creek on June 10, 1997 (Figure 1, and Appendix 1). The ammonia-ammonium, of which un-ionized ammonia is a part, also peaked at the site on the Whitemud River at Arden on June 10, 1997. Also, the ammonia-ammonium at the downstream site at Arden Ridge was lower than it was at the upstream Boggy Creek on June 10, 1997. Stony Creek showed the second highest average un-ionized ammonia in 1997 and, as with high bacteria counts, this warrants further investigation.

Nitrate-nitrite nitrogen levels peaked in the June 10, 1997 sample from the Whitemud River at Arden but did not appear to affect the downstream site at Arden Ridge (Appendix 1). Nitrate-nitrite nitrogen levels were considerably less than the water quality objective of 10 mg/L. This objective is intended to protect human health (Tables 1 and 2).

Total Kjeldahl nitrogen includes ammonia and ammonium as well as organic nitrogen. The Kjeldahl nitrogen also peaked at the Arden site on the Whitemud River on June 10, 1997 (Appendix 1). This peak in Kjeldahl nitrogen did not appear to have influenced the downstream sample at Arden Ridge on June 10, 1997 (Appendix 1).

Total Phosphorus exceeded the water quality objective of 0.05 mg/L in all samples collected at each of the sites except at the Big Grass Drain (Table 2 and Figure 6). Three of seven samples were below the objective at the Big Grass Drain. Phosphorus tends to be relatively high in prairie streams. When the water quality objective is exceeded consistently, growth of algae and rooted aquatic plants are promoted. Phosphorus is contributed from naturally occurring phosphorus in the soils as well artificial fertilizer, manure in run-off, and sewage effluent discharges. Total phosphorus also peaked on June 10, 1997 while dissolved phosphorus peaked on July 15, 1997 at the Arden site on the Whitemud River (Appendix 1). Dissolved phosphorus was the only nutrient to show an overall significant increase between the upstream Boggy Creek site and the Whitemud River site at Arden (Table 3).

With the exception of nitrate-nitrite and dissolved phosphorus, other nitrogen compounds and total phosphorus tended to be lower in the Whitemud River at Westbourne than at the site on Boggy Creek at Neepawa (Table 1). However, between these two sites, nitrogen and phosphorus were elevated and were highest at the sampling site at Arden. Both phosphorus and nitrogen were also relatively high in the Brookdale drain, upstream from the Boggy Creek site. Between the Boggy Creek Site and the Whitemud River at Arden there are a number of potential influences which could affect nutrient loading. These include inputs from Stony and Spring Creeks, and inputs of treated sewage from the sewage lagoons associated with the Town of Neepawa and Springhill Farms. Of these, Stony Creek did not have particularly high phosphorus and nitrogen loading potential. A substantial network of creeks flow into Spring Creek before it discharges into the Whitemud River upstream of Arden and it had the highest average phosphorus of any of the tributary streams. Non-point sources of nutrients would include natural phosphorus, artificial fertilizer, and manure from domestic animals or wildlife.

Dissolved Oxygen

In order to maintain aquatic life minimum levels of dissolved oxygen are required. Where dissolved oxygen saturation levels are not available the objective would be approximately 5 mg/L or greater dissolved oxygen. The highest dissolved oxygen levels occurred at the Pine Creek site. Low dissolved oxygen levels occurred occasionally in the Brookdale drain, Boggy Creek, and the Whitemud River at Arden, Gladstone, and Westbourne. The only location where dissolved oxygen was frequently below 5 mg/L was in the Big Grass Marsh drain (all three samples in 1996 but only one out of four samples in 1997 were lower than 5 mg/L) (Table 2, Appendix 3). It is possible that decaying vegetation may have added to the biochemical oxygen demand in the Big Grass Marsh Drain in 1996.

The water quality objective for the protection of cool water fish and aquatic wildlife is 47 % oxygen saturation. Except for the Big Grass Marsh drain in 1996 and the occasional low level of dissolved oxygen elsewhere most of the dissolved oxygen saturation levels were acceptable (Figure 7).

Chlorophyll a

Chlorophyll a concentrations reflect the abundance of algae. Considering the availability of phosphorus, chlorophyll a concentrations were relatively low (Tables 1, and 2, and Appendices 1 & 2). The only significant change between sites on the Whitemud River was a decrease in chlorophyll a between Gladstone and Westbourne (Table 3). At this point it is possible that phosphorus was being utilized more by rooted aquatic plants.

• Conductivity and the related total dissolved solids increased significantly between the sites at Boggy Creek at Neepawa and the Whitemud River at Westbourne. This was likely were due to the influence of groundwater intrusions and inputs from intervening creeks.

• Significant decreases in the ammonia-ammonium nitrogen complex concentrations occurred between the site at Boggy Creek at Neepawa and the Whitemud River at Westbourne. This was likely due for the most part to the uptake of these nutrients by aquatic plants.

• Total phosphorus concentrations were consistently high with only three samples in the entire study below recommended objectives. Phosphorus levels are often high in prairie streams. Sources of include naturally occurring phosphorus in the soils as well as artificial fertilizer, manure in run-off, and sewage effluent discharges.

• Chlorophyll a levels were not particularly high. It is possible that much of the available phosphorus was being utilized by rooted aquatic plants rather than algae.

• High fecal coliform bacteria counts and moderately high un-ionized ammonia at the Stony Creek site at Neepawa warrant further investigation.

I gratefully acknowledge the assistance of Wayne Hilderbrand and the staff of the Whitemud Watershed Conservation District for their assistance during this study.

Williamson D.A., 1988. Manitoba surface water quality objectives. Manitoba Department of Environment. Winnipeg, Manitoba.