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How Is Water Quality Measured?

Measuring water quality provides evidence of ecosystem health, if water is usable and swimmable, and if users, like within the agricultural industry, are abiding by resource consents and water quality standards.

How to measure water quality
Measuring water quality is important from streams to the sea

Why is Measuring and Monitoring Water Quality so Important?

Measuring and monitoring water quality helps researchers predict and learn from natural environmental processes and determine how our lives impact the ecosystem.

Water quality monitoring, simply put, provides evidence to show if water is suitable for human use and swimability, if it’s providing for local ecosystems, and seeing if users are meeting the conditions of resource consents.

The measurement efforts can assist government agencies, irrigation, construction, mining and aquaculture in understanding water changes and help them minimise their impact, help government companies better manage water resources and understand the quality, and enable Iwi to strengthen the connection with the water, listen to the water, monitor its health, and protect it.

Water Quality Explained

Water quality describes the condition of the water and is often measured for a particular purpose, like seeing if the water is safe for drinking or swimming.

Our water quality is one of the most critical factors of a healthy ecosystem. Clean water supports the diversity of New Zealand’s plants and wildlife.

While it can be hard to comprehend, our actions on land directly affect our water quality.

Alpine rivers and lakes throughout New Zealand have high water quality, meaning the ecosystem is healthy, the water is drinkable, and it supports our wildlife. However, lowland waterways often have serious pollution problems. Urban rivers are the most polluted in the country, as nitrate concentrations worsen and affect our ability to swim in areas of contamination.

What Is Good Water Quality?

To answer, what makes water ‘good’, is the lack of impurities.

For example, low levels of nitrates indicate good water quality, such as bodies of water that measure as containing nitrates under 2.4 mg/L, which is New Zealand’s nitrate limit. But to counteract that, New Zealand ecologists continue to push for a nitrate limit of 1 mg/L, which would put New Zealand in line with the European Union and China.

What is considered good water quality may differ for each individual. Legally speaking, abiding by such standards can deem water as quality. But for communities whose identities are integrated with the waterways, good water quality means no contamination or threat.

Generally speaking, high-quality water is:

  • Odourless and tasteless

  • Does not contain visible solid particles

  • Not contaminated with toxins or chemical

  • Rich in minerals

And safe to consume, use and swim in.

What Are Water Quality Parameters

Water quality parameters include the chemical, physical and biological properties of water, which can be tested or monitored based on the desired water parameters. Water quality parameters frequently sampled and monitored include oxygen, pH, conductivity, and turbidity. Other water quality parameters that are monitored include chemical properties, like nitrate or chloride, or laboratory parameters, such as titration.

Physical and chemical measurements are used to understand and monitor the health of the water. Elements measured include bacteria levels, water clarity, conductivity, pH levels (acidity), nutrient concentrations, and dissolved oxygen levels.

The parameters that affect the quality of water can be physical, chemical or biological. Physical properties include temperature and turbidity. Chemical characteristics involve parameters like pH and dissolved oxygen. Biological indicators include algae and phytoplankton.

These parameters are relevant to surface water quality studies of oceans, lakes and rivers, and groundwater and industrial processes.

Water Quality Indicators

The main water quality indicators that are measured include temperature, acidity (pH), dissolved solids, turbidity (particulate matter) and dissolved oxygen. Each reveals something different about the health of a water body.

Traditionally, measuring water quality meant expensive and timely samples. So someone would physically go to the water body, take a sample, and measure the water quality using that process, but not very often.

How Can Biological, Chemical, and Physical Factors Change the Way Water Quality is Measured?

Physical water properties can be determined by senses like sight, touch, smell and taste – just like understanding the temperature by touch, the colour by floating debris, and the suspended solids by sight.

Chemical factors include pH and alkalinity, which measures water quality based on the pH scale of 0 to 14. Inorganic parameters include total dissolved solids, measuring the salt dissolved in water, and conductivity, the concentration of total dissolved solids related to electrical conductivity or specific conductance.

Biological factors of water quality include algae, phytoplankton and living organisms as a whole. For example, if aquatic life is suffering, this indicates water quality issues. Bioindicators are used for assessing environmental health and biogeographic changes within the water body.

Such factors can change how water quality is measured, from different monitoring equipment to new approaches.

The RiverWatch solution includes five sensors housed in hardware called the Waka, intelligent software and IoT technology known as Signal Mate.

What Are Water Quality Testing Methods?

The five sensors in the Waka include pH, Temperature, Conductivity, Dissolved Oxygen and Turbidity, with room to add two additional sensors. Upgradable sensor options include Nitrate, Chlorophyll and Water Level.

One water quality testing method is through the use of pH sensors. Accurate pH testing reflects water health, ensuring water is safe to use and drink and preventing disease risk.

Monitoring water temperature indicates the metabolic rate of aquatic life and their sensitivity to pollution, parasites and disease.

Conductivity measures the water’s ability to conduct electricity, indicating what is dissolved in water.

Dissolved oxygen indicates an aquatic resource’s ability to support aquatic life, which shows water health.

Turbidity measures solids in water using the amount of light that can pass through. Turbidity readings can indicate potential pollution and degradation.

Water Quality Measuring Instruments

Water measuring instruments beyond the traditional sampling solution include various options. Some specific instruments include advanced dissolved oxygen sensors, an electrical conductivity logger, or a multi-parameter instrument, and more.

Smart Water Quality Measuring Solution

The AquaWatch mission is to empower New Zealand to achieve clean, swimmable rivers and streams through providing real-time water quality information. We’re committed to restoring and enhancing freshwater.

We aim to become zero waste and carbon positive. The goal is to provide sustainable management of New Zealand’s rivers and streams through a full lifecycle water quality monitoring product.

Improving How Water Quality is Measured

Water quality is a critical part of environmental monitoring. When water quality is poor, it affects aquatic life and, essentially, the whole surrounding ecosystem.

Water quality monitoring is an adaptive solution for finding out what is happening in our waters in real-time rather than after it has happened. The Waka water quality monitor is suitable for any water environment to benefit the community.

Real-Time Water Quality Data

Water monitoring is how information is gathered about the condition and quality of rivers, lakes, estuaries and coastal waters. A real-time water quality system measures the quality of waters using interpretative software and IoT connectivity.

While there are various ways to monitor water conditions, water quality monitors include sampling the chemical condition of water and measuring constituents like acidity and nutrients. Physical conditions can also be monitored, including temperature and sediments of stream banks and shores.

Get in touch with us to learn more about AquaWatch and our innovative water quality and river monitoring solution.



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