Certified Lake Manager, Ashlee Haviland, walks through what constitutes water quality, water quality management, monitoring strategies and the key health indicators that are used to inform each of these.
It’s certainly not groundbreaking that all living organisms – algae, plants, insects, animals and humans need and use water. It plays a vital role in survival. However, if there is one thing that matters more than the availability of water, it’s the quality of water at hand.
Water quality directly influences the overall well-being of life. Therefore, proper attention should be given to the management of water quality in our communities to ensure they are kept healthy and comfortable.
Water quality can be thought of as a data-backed statement of how healthy and fit a waterbody is for its intended purpose – whether that’s recreation, a drinking water source or drainage. Water quality is made up of a myriad of data measurements, referred to as key water health indicators, that encompass the physical, chemical and biological characteristics of a waterbody based on its usage as well as direct and indirect impacts on flora and fauna. It is the norm against which water management practices are performed for and their successes measured against. Water quality and its associated water health indicators help determine the:
It’s influenced by three primary sources – the surrounding ecosystem, local geology (the minerals, sediment, and porosity of the area’s geogenic factors) and human contributions (the pollution, usage, impacts from rural development and suspended sediment).
Even beyond the biological necessity for water, high water quality is needed for lakes, ponds and drainage systems to perform well. For example, there are only certain species that will flourish under excellent water quality conditions, which can be key indicators for ecosystem health.
Some other, common needs for high water quality include:
So, what standard should the key health indicators of a waterbody meet when it comes to water quality?
The United States Environmental Protection Agency (EPA) has developed drinking water quality standards that promote public health. Often, Maximum Contaminant Levels (MCL’s) are also established to aid with this. While most of these regulations pertain to drinking water, municipalities, non-profits and watershed groups may establish their own standards to maintain high quality of the water that directly impacts their communities. With this in mind, the data that is tested, collected and treated for is customized to the water’s specific purpose. This is all accomplished through ongoing water quality management.
Water quality management consists of an ongoing cycle aimed at improving and maintaining high water quality for a specific body of water. This cycle starts by determining what standards it needs to meet to achieve optimal water quality, then analyzing where these quality standards currently stand via key water health indicators testing, followed by determining and implementing strategies to optimize the water to meet these standards. It rounds off with consistent monitoring and further management strategies as may be needed.
As you can see in this cycle, water quality management involves two main practices —monitoring and control.
Water quality monitoring tracks these factors using key water health indicators on a consistent, periodic basis. This information and data are then analyzed by aquatic biologists and lake managers to determine water quality status and needs for improvement.
The control portion implements the necessary actions needed to regulate that water quality. This may consist of aquatic plant management treatments via herbicide or mechanical harvesters, aeration systems, dredging, biological augmentation or conservation practices that implement best management practices within watersheds.
There are three major aspects to monitoring water quality that should be implemented in any community’s water quality management program.
This monitoring focuses on the physical features of the body; that is, it uses sensory observation to access the physical indicators of water quality. This phase of monitoring inspects properties that are detectable by the senses. Physical indicators of water quality include:
Color: Pure water is colorless. However, the presence of certain minerals in water can bring about color in water bodies. For example, an iron-rich body of water may be reddish-brown in color.
Turbidity: A turbid water body is one that is clouded due to solid and colloidal suspensions present in it. Turbidity measurements often indicate water quality based on clarity and calculated total suspended solids in the water body.
Temperature: Temperature describes how hot or cold a body of water is. Water temperature is crucial in assessing water quality as it influences other physical, chemical, and biological properties of a body of water.
Odor: Oftentimes, odors in ponds and lakes are due to various biological activities: the action of microorganisms, decaying organic matter, algae, industrial activities, etc.
The physical assessment of a body of water also reports the flow, width, and depth of the body.
There are also various chemical key water health indicators that can be tested and monitored. This approach is key in determining the sources of pollution, identifying specific pollutants and formulating effective solutions. Some of these key water health indicators include:
Dissolved Oxygen: Dissolved oxygen measures the amount of oxygen available to sustain life in an aquatic ecosystem. A low level of dissolved oxygen may be due to excessive algal growth and high levels of organic waste decay. Low dissolved oxygen levels are a stressor to aquatic plants and animals, while high DO supports aquatic life.
PH: PH is the measure of hydrogen ion concentration in a body of water. The pH scale ranges from 0–14, with 7 being neutral, 0–3 being highly acidic, and 9–14 being highly alkaline. Water should be within a pH of 6.5-8.5.
Nitrates: Nitrates are a form of nitrogen, which is an essential element for aquatic plant and animal life. Nitrates promote plant growth and, in healthy amounts, are beneficial to water. However, nitrates are dangerous in excess amounts because, together with phosphorus, they cause eutrophication and raise biological oxygen demand, decreasing the dissolved oxygen available for use in the aquatic ecosystem.
Total Phosphorus: Phosphorus is counted as the limiting nutrient in aquatic ecosystems, i.e., phosphorus directly impacts the growth of algae and aquatic plants. Thus, it’s an essential element in water quality monitoring.
Secchi Disk Test and Depth: A Secchi disk test is used to measure the clarity – or turbidity – of water. The actual disk is lowered into the water until it is no longer visible. This depth is measured and known as the Secchi depth.
Total Suspended Solids (TSS): A measure of the solid materials suspended in water, including silt, plankton and industrial waste residue, that can absorb light and inhibit plant growth. This residue largely comes from runoff, sediment erosion and algae growth.
Conductivity: Conductivity refers to the water’s ability to pass an electrical current and is affected by its temperature: the warmer the water, the higher the conductivity. Changing conductivity rates can indicate that a discharge or other source of pollution has infiltrated the waterbody.
This approach uses the health of the fauna and flora – such as macroinvertebrates – present in the body of water as a measure of water health. Generally, macroinvertebrates have limited migration patterns and, as such, may be used to assess the health of a local water body as well as project the type and degree of pollution in an aquatic ecosystem.
Biological monitoring also assesses various biological matrices such as algal growth, fish sampling, and invertebrate sampling.
Chlorophyll-a: This refers to a measure of the number of algae within a waterbody and can be used to classify the trophic condition of it. Excess amounts can cause bad odors, scum build-up and low DO levels.
Pollution Sensitivity: Certain organisms can only inhabit unpolluted water due to their high sensitivity to pollution, while others may survive well in polluted water. The numbers of each group of macroinvertebrates indicate the health and purity of the water. The presence of large numbers of pollution-sensitive organisms in a body of water is an indicator of water health. On the other hand, large amounts of pollution-tolerant species and the absence of or minimal presence of sensitive species indicate severe pollution.
Clarke’s comprehensive water quality testing and monitoring unearth vital information for the management and restoration of your lakes, ponds and other waterbodies. It’s information integral to any management program.
Discover how these tests can help streamline and appropriately address your water’s concerns.