Water Quality Monitoring

“It is widely accepted that the land surrounding a body of water influences the health of that water. This means that the land-uses and activities that take place around a body of water will have an impact on its water quality. 

One thing all streams in our watershed have in common is degradation of water quality related to the land-uses in their drainage areas. Land and water are intimately connected and that is evidenced in the data that has been collected by the PWA for the past 19 years”.

– Jenna MacQuarrie, Project Manager


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The Petitcodiac Watershed Alliance (PWA) is celebrating our 20th year monitoring water quality in the Petitcodiac and Memramcook Watersheds!

Since our beginnings as a volunteer initiative in 1997, the PWA has sampled multiple sites within the watershed with the help of the New Brunswick Department of Environment and Local Government. In 2003, the we partnered with l’Université de Moncton to implement a cost effective long- term water quality program with financial support from the Environmental Trust Fund. The long-term data that has been collected by the PWA can now be used to determine changes, positive or negative, within sub-watersheds of the Petitcodiac and Memramcook Rivers.

We contribute the data we collect to databases including the Community-Based Environmental Monitoring Network (formerly CURA H2O), a program out of St. Mary’s University, the WWF’s Freshwater Health Assessment and the Waterkeeper Swim Guide. We also work with local municipalities to alert them when water quality is being degraded, and contribute towardss their efforts to create healthier waters within the Petitcodiac Watershed.
You can find our most up-to-date data for streams you are interested in on the “Our Watersheds” page.

The following is a list of the parameters we sample for. This information has been taken directly from our 2016 Water Quality Report which can be found on our Publications page. All referred to sources of information are listed in the references section of the report.


Total Coliform & Escherichia coli

Coliform bacteria are a commonly used bacterial indicator of water quality (Griffin et al., 2001; Noble et al., 2003). They are commonly found in the environment in soils and vegetation. Coliforms can be found in the aquatic environment and are present in mammalian intestines. While coliforms themselves do not cause illness, their presence indicates that a watercourse may be susceptible to contamination by other microorganisms (Nova Scotia Environment, 2009). Escherichia coli (E.coli) is the only member of the total coliform group of bacteria that is found only in the intestines of mammals, including humans. The presence of E.coli in water indicates recent fecal contamination and may indicate the possible presence of disease-causing pathogens, such as bacteria, viruses, and parasites. Although most strains of E.coli bacteria are harmless, certain strains, such as E.coli 0157:H7, may cause illness. One cause for high coliform content in rivers and streams is the presence of raw sewage being discharged into the watercourse (USA Water Quality, 2008).

Notable results:

Bacterial values at each site displayed a peak at some point throughout the season compared to other months, usually from June-August. The exception of this trend being Rabbit Brook, which exceeded the recreational guideline for bacteria (>200 Most Probable Number/100 ml sample) on all occasions.

Dissolved Oxygen

Dissolved oxygen (DO) is a commonly used parameter for measuring water quality (Sánchez et al., 2007). It is influenced by a collection of physical, chemical and biological characteristics such as temperature, salinity, wave action, and current (Spanou and Chen, 1999; Cox, 2003; Mullholand et al., 2005; Quinn et al., 2005, USGS, 2014). DO is one of the most fundamental parameters in water for all aquatic life. Low concentrations directly affect fish and alter a healthy ecological balance. Because DO is affected by many other water quality parameters, it is a sensitive indicator of the health of the aquatic system (CCME, 1999). A dissolved oxygen level that is too high or too low can affect water quality and harm aquatic life. The amount of dissolved oxygen needed is species-specific and can vary within a species based on their life stage (Breitburg, 1994; CCME, 1999). If a watercourse does not have adequate levels of dissolved oxygen aquatic organisms will be unable to inhabit them.

Notable results:

Dissolved oxygen levels tended to decrease in the summer months when water temperatures were higher. High thermal inputs in the summer months are leading to levels falling below the recommended levels of dissolved oxygen for cold-water species. Dissolved oxygen levels are lowest at streams with stagnated waters, low flows and impoundments.


Nitrates & Phosphates

Nutrients for our purpose refers to available nitrates and phosphates. The two dominant sources of nutrient pollution is from agricultural and wastewater runoff as well as the production of fossil fuels (Howarth et al., 2002). If nutrient levels are too high eutrophication can occur, which can contribute to algal blooms and greatly threaten water quality (Anderson et al., Howarth et al., 2002). Nitrate (NO3) is a form of nitrogen found naturally in terrestrial and aquatic environments. Other forms of nitrogen include ammonia (NH3) and nitrite (NO2) (USEPA, 2012). These forms of nitrogen have the potential to undergo nitrification to nitrate when released into surface waters (CCME, 2012). Phosphate (PO43-) is also a naturally occurring nutrient in terrestrial and aquatic environments. However, in high concentrations, phosphate can consume dissolved oxygen contributing to eutrophication in lakes.

Notable results:

Nitrate levels jumped in June in comparison to May levels, usually peaking in the summer. Phosphates levels exhibited the same trends. Trends seem to be less associated with land-use, as some of the nutrient levels in rural areas were lower than in urban areas. Rabbit Brook, North River, Stony Creek, Memramcook River, the South Branch of the Memramcook River and Hall’s Creek West all had higher phosphate and nitrate levels compared to the rest of the sites. The correlation between sites with peak nitrates and phosphates compared to other probably indicates fertilizer or nutrient run-off of some sort at these sites.


pH is the logarithmic measurement of free hydrogen ions in solution. This will determine whether the solution in question is acidic, basic, or neutral. The scale is measured from 1 to 14. Values <7 are considered acidic, while values >7 are considered basic. A value of 7 indicates that the solution in question is neutral. Because this scale is logarithmic the difference in numbers on the scale are tenfold in concentration. For example, a solution with a pH of 2 is not twice as acidic as a solution with a pH of 4 but one hundred times more acidic. Environment Canada indicates that healthy surface water should have a pH that falls between 6 and 8 (Environment Canada, 2013). Factors affecting the pH of surface water include acid rain, geography of the area surrounding the water, and waste water runoff. Low pH levels cause chronic stress that may not kill individual fish, but can lead to lower body weight and smaller size and makes fish less able to compete for food and habitat (USEPA, 2012). In high pH environments the effects on fish can include death, damage to gills, eyes, and skin, and an inability to dispose of metabolic waste (Locke, 2008).

Notable results:

Streams in the Memramcook sub-watershed which are stagnated also have very low pH values in the summer months.  pH in the Memramcook River Watershed are lower relative to the Petitcodiac system. This could be attributed to the differences in geology between the two systems (Appendix 2 of Report).

Specific Conductivity

Specific conductivity is a measure of water’s ability to carry an electrical current and is recorded in microsiemens per centimeter (s/cm) (USEPA, 2012). Conductivity is influenced by the presence of inorganic dissolved solids such as chloride, nitrate, sulfate, phosphate, sodium, magnesium, iron, and aluminum (USEPA, 2012). There is no set range of values that are deemed necessary for a healthy aquatic ecosystem, however, Environment Canada has set a limit of 500 S/cm (Environment Canada, 2013). Most streams have conductivity that fluctuates within a certain range which can serve as a background for long-term monitoring. If measurements are recorded outside of the typical range it can be an indication of a change in the stream chemistry due to increased dissolved solids in the water from discharge or point pollution (USEPA, 2012).

Total Dissolved Solids

Total dissolved solids (TDS) is the measure of dissolved inorganic material in water that is less than two micrometers (µm) in diameter and is measured in milligrams per litre (mg/L) (Weber-Scannell and Duffy. 2007). Like conductivity there is no set range of values deemed acceptable, however, with enough background data, a normal range can be determined. If this range is set and TDS does fluctuate outside of background norms it can serve as an indication that something is being introduced into the water system. Wastewater runoff, pollution, agriculture and geography are all factors in contributing to TDS measurements (Weber-Scannell and Duffy, 2007).

Notable results:

Fox Creek and Memramcook River are tidal at our sites, and therefore our brackish water data makes it difficult to gauge their freshwater health relative to the other sites. Although North River has a naturally high salinity, Rabbit Brook, Hall’s Creek West, and Jonathan Creek all have unnaturally high conductivities, total dissolved solids levels and salinities compared to rural streams. Streams that flow through areas with higher urban development displayed consistently poor quality across the majority of parameters.


Turbidity is the measure of relative clarity of a liquid. It is an optical characteristic of water and is an expression of the amount of light that is scattered by material in the water when a light is shined through the water sample (CCME, 2002). The higher the intensity of scattered light, the higher the turbidity. Materials that cause water to be turbid include clay, silt, finely divided inorganic and organic matter, algae, soluble colored organic compounds, and plankton and other microscopic organisms. During periods of low flow (base flow), many rivers are transparent with varying colour, and turbidities are low, usually less than 10 NTU (Minnesota Pollution Control Agency, 2008). During a rainstorm, particles from the surrounding land are washed into the river making the water a muddy brown color, indicating water that has higher turbidity values. Also, during high flows, water velocities are faster and water volumes are higher, which can more easily stir up and suspend material from the stream bed, causing higher turbidities (CCME, 2002).
High concentrations of particulate matter affect light penetration and productivity, recreational values, and habitat quality, and cause lakes to fill in faster. In streams, increased sedimentation and siltation can occur, which can result in harm to habitat areas for fish and other aquatic life. Turbidity affects hatching success hatching success as it clogs gills in fish and smothers eggs by reducing the efficiency of absorbing dissolved oxygen in the water (CCME, 2002). And can affect foraging efficiency in species at risk, such as the Eastern painted turtle (Chyrsemys picta), (Grosse et al., 2010), interactions between fish and dragonflies (van de Meutter et al., 2005), and feeding on species of zooplankton (Helenius et al, 2013), by decreasing visibility within the water column. Aquatic plants are important as they create oxygen within the water column. Turbidity can limit light penetration, causing plants to die. Aerobic bacteria then begin the process of decomposition which uses up more oxygen, leading to lower dissolved oxygen content in water for aquatic life. Particles also provide attachment places for other pollutants, notably metals and bacteria. For this reason, turbidity readings can be used as an indicator of potential pollution in a water body (CCME 2002).

Water Temperature

Water temperature is an important factor influencing many river processes such as leaf decomposition (Webster and Benfield, 1986) and animal life history (Sweeney 1984). Temperature determines which organisms are able to survive and live in a certain environment. Every species has a critical upper and lower thermal limit (Ministry of Environment BC, 2001). These temperature limits can be of a wide or narrow range and can vary both within and among species in order for them to thrive (Ministry of Environment BC, 2001). Lower water temperatures are typically better for most fresh water fish native to our region. Water temperature governs metabolic processes in most fishes and determines their ability to survive in a certain environment (Claireaux, 2000). Fish found in the Petitcodiac and Memramcook watersheds that are sensitive to temperature include brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo salar). The optimal water temperatures for these two species are 13°C – 18°C and 14°C – 20°C, respectively (DFO, 2012). Higher water temperatures can put individual fish at a competitive disadvantage in the wild due to physiological stress (DFO, 2012). Prolonged exposure to temperatures greater than 24°C is lethal for trout and salmon species (MacMillan et al., 2005). Temperature can be influenced by a number of factors such as sun exposure and streamside shading, size and depth of the water, elevation, water velocity, waste water runoff, and anthropogenic impact from recreational activities (USGS, 2014).

Notable results:

Temperature at our monthly monitoring sites is highest in the rural streams in the upper Petitcodiac river system, and waters from impounded areas. This could be due to the fact that water bodies we sample in this area are for the most part at the mouth of wide rivers. The ThermoBlitz enlightened us on the locations of high temperatures as well as areas with potential cold inputs on ecologically important streams.



Actions to protect from anthropogenic influences need to be taken to improve or maintain water quality in all of the areas within our watershed. This requires a broad range of actions from our organization to contribute to the improvement of water quality in both rural and urbanized areas. Community-wide efforts need to be made in order to slow the effects of development and urbanization, as well as promote positive land-uses in rural areas. Education and outreach programs need to be delivered in a citizen-friendly, direct manner to achieve a higher level of understanding within our communities. We hope this awareness of how residents can positively affect local ecology translates stewardship in our watershed, other watersheds, and at larger scales as well. Increased development and impervious surfaces are contributing a larger volume of runoff to our waterways. Streams that flow through rural areas are not influenced by runoff to the same extent because the land surrounding them is able to absorb some of the overland flow. There is a reduced volume of water entering these waterways and thus a reduced level of pollutants. After reviewing previous reports it has been noted that there is a decline in water quality as urbanization increases. Watercourses that flow through urban areas are subject to greater stormwater runoff as they are surrounded by land that is unable to absorb water due to high levels of impervious surface. Stream urbanization is being observed in all waterways that flow through developed areas. In contrast to urban streams, watercourses found in more rural areas had consistently better water quality. These rivers and streams receive less input from storm and sewer lines and are also surrounded by land that is able to absorb some overland runoff. Anthropogenic effects in these areas are minimal and water quality is reflective of this.The cause of declining water quality cannot be attributed to one specific event or activity but rather a culmination of events and activities. Increased development in riparian zones leads to removal of important riparian vegetation, and an increase in sedimentation and overland runoff during precipitation events. Expanding urban areas results in greater volumes of impermeable surfaces, leading to stormwater being discharged into waterways. Care should be taken to talk to residents about riparian vegetation and its importance throughout the entire watershed.

Best Management Practices in Rural Areas

Removal of vegetation on the Little River and North River can be devastating to water quality, and in turn the organisms which call these rivers their homes. Runoff from agricultural land and lawns can carry excess nutrients, such as nitrogen and phosphorous into streams, lakes, and ground-water supplies, which have the potential to degrade water quality. The headwaters of the Pollett River, Little River, Anagance River and North River are incredibly important for conservation. Headwaters are important spawning areas for species at risk, so if they disappear, these populations will not be able to continue.

Improved Monitoring of Temperature in Rural Streams

Temperature is highest in the rural streams in the upper Petitcodiac river system. This could be due to the fact that water bodies we sample in this area are for the most part at the mouth of wide rivers. Dissolved oxygen levels tended to decrease in the summer months when water temperatures were higher. High thermal inputs in the summer months are leading to levels falling below the recommended levels of dissolved oxygen for cold-water species.
Temperature has influence over other parameters and it would be helpful if the PWA could place temperature loggers on their tributaries to monitor fluxes in daily temperature. Low and fluctuating DO levels can render a stream or river not only uninhabitable for fish but other aquatic species as well such as invertebrates (Dean and Richardson, 1999).Using this data we can infer the state of the select tributaries at any point given their usual levels. Seeing a variation from normal not attributed to fluctuations in temperature could help us to diagnose an input to the water quality. Better monitoring of temperature on our very ecologically important, rural rivers will help us to better understand where sources of thermal inputs are, as well as important thermal refuges for cold-water species, such as the endangered iBoF Atlantic salmon. Removal of barriers to stream flow in rural areas will help to improve water quality in these streams, increasing the amount of suitable upstream habitat.

Removal of Blockages to Water Flow in Rural Streams

The sampling location in Meadow Creek is downstream of a culvert outfall. In the PWA 2012 Water Quality Report is was described as “occasionally stagnant due to backflow”. In 2015, the site was stagnant on every sampling occasion, indicating that there is a permanent blockage downstream. This leads to lower oxygen and pH levels, making this unsuitable habitat for fish. It was also noted in the same PWA 2012 report that beaver activity is common throughout this sub-watershed. The cause for the pooling at these sites should be investigated, hopefully leading to a solution to the problem, and restoring flow to these streams.

Low-Impact Development in Urban Areas

Our urban streams, in particular Rabbit Brook is influenced by raw sewage discharge, stormwater run-off, melting snow dump inputs and alterations to its stream path. Promotion of Low Impact Development (LID) may prove to be beneficial. The PWA should work with government and municipalities to encourage policies which promote and require use of permeable pavement and retention of riparian vegetation, which can also serve as conservation corridors. The City of Moncton published their PlanMoncton: 2014 Municipal Plan, which noted all planning activities should to include considerations to stormwater management and conservation zones around its urban streams. It is important for the PWA to help them achieve their sustainability goals where possible.

Stormwater Management

Surface water runoff is generally contaminated with a number of substances that can adversely affect the water quality in freshwater streams including hydrocarbons, vehicle fluids, faecal matter, sediment and even heat.  When precipitation falls in a well forested watershed, most of the precipitation is slowly absorbed into soils through infiltration. This water is then stored as groundwater, and is slowly discharged to streams through springs. This type of infiltration is also helpful in mitigating the effects of flooding, because some of the runoff during a storm is absorbed into the ground, thus lessening the amount of surface water runoff.
As watersheds are urbanized, much of the vegetation is replaced by impervious surfaces and the amount of infiltration that can occur is reduced. As a result the amount of stormwater runoff increases. In a developed watershed with a lot of impervious surface area, much more water arrives into a stream much more quickly, resulting in an increased likelihood of more frequent and more severe flooding. Reducing the amount of impervious surface areas in urban development is a sustainable development strategy that should be encouraged. PWA’s Water Quality Reports over the last 5 years (PWA 2012; 2013; 2014; 2015; 2016) have all identified stormwater management as the largest issue to urban water quality within our watershed. In urban areas, the aged infrastructure that collects run-off in extensive drainage systems that combine curbs, storm sewers, and ditches to carry stormwater runoff often directly to streams need to be re-evaluated by our municipalities. If we want to have healthy urban streams, we need to stop treating them like ditches. This requires a need to make municipalities aware of modern stormwater management practices, and encouraging green infrastructure as a supplement to increasing infrastructural need to deal with increasing storm events and precipitation volumes. Municipalities need to be encouraged to use these as solutions instead of maintain the status quo of using streams as stormwater ditches.


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