Water Quality Monitoring in the Milk River

The program forms the baseline for long-term water quality monitoring in the Milk River watershed.

A water quality monitoring program was initiated in 2006 in partnership with the Milk River Watershed Council Canada, Alberta Environment, Cardston County, County of Warner, County of Forty Mile, Cypress County and Writing-on-Stone Provincial Park.

Water samples are collected from the headwaters of the Milk River (the entry point of the North and South forks into Canada) and from 8 other locations downstream every two weeks from April through October. Tributary sites include are Miner’s Coulee and Red Creek when they are flowing. These tributaries often dry up by mid to late June. Water samples are analyzed for fecal coliforms, E.coli bacteria, nutrients, salts and sediment.

Location Maps

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See where stream flow monitoring stations are located throughout the Milk River Watershed.

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Locations of water quality monitoring stations and water quality data index in 2006 and 2007.

Water Quality Reports

Data Stream

The Milk River historic surface water quality data can now be accessed on DataStream, an open-access platform for water quality data, with the aim of promoting knowledge sharing and advancing collaborative water stewardship. The Milk River data can be accessed at: https://doi.org/10.25976/33tj-bs38

Screenshot of Data Stream

About Water Quality Monitoring

Water monitoring is a valuable tool that allows resource managers to better understand the status of resources in the watershed and can assist with watershed management planning and decision-making. The monitoring of specific parameters (e.g., streamflow, salt, nutrients or others) can be used to determine if water is suitable to meet the desired end uses for that water, including irrigation, livestock water and recreation.

Read Research and Science Note 5: Water Quality Research (2006-2009)

The Milk River Watershed Council Canada (MRWCC) has been monitoring water quality in the Milk River since 2006 in partnership with local municipalities and the provincial government.  The objectives of the monitoring program are to:

  • Collect baseline water quality data for the Milk River.
  • Determine if present water quality is meeting Water Quality Objectives established in the Milk River Integrated Watershed Management Plan (MRWCC 2015) and other applicable water quality guidelines such as the Alberta Surface Water Quality Guidelines (ESRD 2014).
  • Use results to encourage continued land and water stewardship and inform decisions regarding the future management of the Milk River and its tributaries.

The MRWCC and partners collect 10 samples during the open water season (e.g., April through October) at five locations on the mainstem of the Milk River and at major tributaries (i.e., Battle, Lodge, Middle and Red creeks).  Samples are analysed for temperature, dissolved oxygen, specific conductivity, nutrients (phosphorus and nitrogen), total suspended solids and fecal coliform bacteria.

Water Quality Indicators

Conductivity: is the measure of salts (e.g., sodium, chloride, magnesium, potassium) dissolved in water or the salinity.  Specific conductivity values greater than 1000 µS/cm can negatively affect irrigated crops by impeding nutrient uptake.

Phosphorus: is the limiting nutrient in freshwater that controls plant growth. In excess, it leads to increased productivity (e.g., algae blooms, dense aquatic plant growth) via process known as “eutrophication”.  Phosphorus is present naturally, and is found in organic and inorganic fertilizers and detergents.

Nitrogen: is also a nutrient in freshwater that is used by plants for growth.  Generally nitrogen is reported as Total Nitrogen which is the sum of nitrate-nitrogen (NO3-N), nitrite-nitrogen (NO2-N), ammonia-nitrogen (NH3-N) and organically bonded nitrogen. Elevated concentrations of nitrate can result in the excessive growth of algae and aquatic plants. High concentrations of nitrate can pose a toxic risk for infants (if ingested) and livestock watering.

Total Suspended Solids (TSS) is a measure of the suspended particles such as silt, clay, organic matter, plankton and microscopic organisms which are held in suspension in water.  Suspended solids can transport nutrients and contaminants downstream and may be aesthetically undesirable. Excessively high TSS in irrigation water can cause the formation of crusts on top of the soil which can inhibit water infiltration, and plant emergence and impede soil aeration. The formation of films on plant leaves can reduce sunlight and impede photosynthesis. High TSS can interfere with the treatment of drinking and industrial process water. As high concentrations of TSS settle out, the capacity of irrigation reservoirs and canals can be lowered, requiring dredging and higher maintenance costs.

Fecal Coliform Bacteria (FCB) are specific to the intestinal tracts of warm-blooded animals (e.g., cattle, birds, pets) and humans and are a specific test for animal waste or sewage contamination. FCB can enter surface waters through fecal contamination by wildlife, domestic animals and through wastewater discharges or surface water runoff. Fecal coliform bacteria are not necessarily harmful to human health, but they indicate fecal contamination and the possible presence of other pathogenic organisms including Escherichia coli (E. coli), SalmonellaGiardia and Cryptosporidium which can have serious health implications affecting drinking water, irrigation, livestock watering and recreation (BRBC 2008). FCB can be a concern for fresh garden produce particularly leafy crops such as lettuce. Fecal coliform bacteria levels are expressed as the number of bacteria colonies per 100 mL of water.

Milk River Water Quality Objectives

The Milk River Integrated Watershed Management Plan established water quality objectives for the Milk River that represent the natural flow period and the diversion flow period during the open water April – October season.

The Water Quality Objectives are defined as the WQO-50 and the WQO-90.  The WQO-50 is the water quality objective representing the 50th percentile or median (middle) value in the historic data set.  Fifty percent of the values are above the median and fifty percent are below the median.  The WQO-90 is the water quality objective representing the 90th percentile value in the historic data set.  Ninety percent of the values in the historic data set are below the 90th percentile and ten percent are above.

Annual and periodic evaluation of WQOs will determine if water quality is within a normal range, cautionary range or exceeds the objective by a substantial margin (Figure 1).

It is expected that the WQO-50 and the WQO-90, which are based on historic data, will be exceeded in the future.  The intent is to determine whether the annual water quality is deviating away from the objectives and whether this deviation is significant.