How does Ioticiti measure water quality?

There are several measurements that we at Ioticiti take to assess the health of waterways like ponds, rivers, and lakes. These are measurements that leading authorities such as the US Geological Service (USGS) and the Environmental Protection Agency (EPA) have studied and used in their own assessments for decades.

Each measure in isolation can provide different insights, but it is the relationships between them that gives us a comprehensive assessment of the health of water systems. Here is a brief explanation of those water quality parameters, how they’re related, and why they matter.

Dissolved Oxygen

Although water molecules contain an oxygen atom, aquatic organisms — from microorganisms to fish — must rely on a different form of oxygen to survive. This is dissolved oxygen, and it’s a critical measurement.

According to the USGS, bacteria in water consumes oxygen as organic matter decays. Excess organic material can cause oxygen-deficiency which if left unchecked, can lead a water body to “die.” Stagnant water is particularly susceptible since organic matter tends to accumulate there, and water ecosystems can be at higher risk in the summer. This is because the concentration of dissolved oxygen is inversely related to water temperature.

pH

pH affects most chemical and biological processes in water. According to the EPA, different species flourish within different ranges of pH, with the optimal range for most aquatic organisms falling between pH 6.5-8.

Fluctuating pH or sustained pH outside this range physiologically stresses many species and can result in decreased reproduction, decreased growth, disease or death. pH also alters the chemical state of many pollutants (e.g., copper, ammonia), changing their solubility, transport, and bioavailability which can increase exposure to and toxicity of metals and nutrients to aquatic plants and animals.

Certain human activities can have a strong effect on pH including agriculture (e.g., animal feedlots), urbanization (e.g., vehicles), industry (e.g., coal-fired power plants) and mining (e.g., acid mine drainage). These typically enter water systems through stormwater runoff, leakage or leachate into groundwater sources, or from the atmosphere as rain.

You can’t typically observe or feel a pH change hence the importance of measurements.

Oxygen Reduction Potential (ORP)

This is often referred to as the “redox” conditions: whether water is oxic (oxidized) or anoxic (reduced). It’s especially important to measure in groundwater, which according to the USGS, serves as a strong indicator of elevated levels of contaminants.

For example, concentrations of arsenic and manganese are more likely to be present at levels that exceed human-health benchmarks in anoxic groundwater, and concentrations of uranium, selenium, and nitrate are more likely to exceed their benchmarks in oxic groundwater. This measurement can also determine whether some contaminants are travelling with the groundwater, reacting with other materials in aquifers (from which we often draw water for human use), or are degrading into other chemicals.

As a result, the redox condition of groundwater helps us predict what contaminants might be present in groundwater at levels of concern for human health.

Turbidity

Turbidity is the measure of relative clarity of a liquid. According to the USGS, clay, silt, tiny pieces of inorganic and organic matter, algae, dissolved coloured organic compounds, plankton and other microscopic organisms can all affect water turbidity.

High levels of turbidity (i.e. lower clarity) can affect light penetration and ecological productivity, habitat quality, and the speed at which water bodies fill. In streams, increased sedimentation and siltation can damage the habitat of fish and other aquatic life. Particles also provide attachment places for other pollutants, notably metals and bacteria.

As a result, we use turbidity readings can be used as an indicator of potential pollution in a water body.

Conductivity

The EPA defines conductivity as the water’s ability to pass an electrical current. Because dissolved salts and other inorganic chemicals conduct electrical current, conductivity increases as salinity increases. Organic compounds like oil do not conduct electrical current very well and therefore tend to reduce the water’s conductivity.

Conductivity is also affected by temperature: the warmer the water, the higher the conductivity.

Each water body tends to have a relatively constant range of conductivity that, once established, can act as a baseline for comparison with regular conductivity measurements. Significant changes could be an indicator that discharge or some other source of pollution has entered the aquatic resource.

Generally, human disturbance tends to increase the amount of dissolved solids entering waters which may increase conductivity.

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These are only a few of the key water quality parameters that Ioticiti measures. Others include changes in depth and in- and out-flows (for flooding management), temperature (both water and air), salinity and others.

Connect with us to learn more about Ioticiti’s water monitoring solutions and how they might be able to help your city or enterprise.