Algal Blooms and Their Impact on Local Water Quality

Algae blooms in waterway

Water, Water, Everywhere—But Not Always Ready to Drink

Our planet is covered by 70% water, yet only 3% of that water is fresh.[1] Of that, about 1.2% of the world’s freshwater can be used as drinking water.[2] Climate change is limiting access to potable water even more, causing shortages, droughts, and floods. World Water Week is an international awareness holiday celebrated every year from August 24rd through August 28th. With a mission to address global water challenges, this year’s event focuses on the impact of climate change and the growing threat to water access globally.

It’s not access to freshwater that is challenging—keeping it drinkable is a continuous challenge when it comes to managing local water quality. The intersection of global warming and man-made pollutants has precipitated a particularly problematic development: harmful algae blooms. Scientists predict that the effects of climate change, along with the increased demand of a growing human population might also cause larger harmful algal blooms to occur more frequently, further threatening our access to clean drinking water.

In this blog, the Quench Water Experts explain how climate change is causing larger harmful algal blooms and what that means for your drinking water. But before we get into how algae can affect your local water quality, let’s first explain what causes harmful algal blooms.

What are Harmful Algal Blooms?

An algal bloom is a rapid increase or accumulation of algae. Not all algal blooms are considered dangerous to humans and the environment. In fact, much of Earth’s oxygen is generated by algae. Algae are also the base of food webs in freshwater ecosystems and can range from microscopic, single-celled organisms to large seaweed.

High concentrations of nutrients and warming water is what causes harmful algal blooms. Harmful algal blooms produce toxic chemicals and some blooms eat up the oxygen in the water, killing off fish and other aquatic life.[3] Not all algal blooms are harmful, though. In some cases, algal outbreaks only discolor water, produce a smelling odor, and/or add a bad taste to drinking water.[4]

There is also a type of bacteria that sometimes coincides with large algal blooms as well called blue-green algae (cynobacteria). Some species of blue-green algae produce harmful toxins, which take effect when ingested or inhaled. It can also be harmful when it touches the skin.

How Climate Change Affects Algal Blooms

As we mentioned in the introduction, climate change is a major reason for what causes harmful algal blooms to worsen over time. Warming water temperatures create an ideal habitat for algae and small organisms. Higher temperatures allow algae to grow thicker and faster. The heat also enables algae to float to the surface faster and absorb more sunlight, making water even warmer and promoting more blooms.

Other climate impacts that the Environmental Protection Agency (EPA) says might affect algal blooms include changes in water salinity, higher carbon dioxide levels, changes in rainfall, sea-level rise, and coastal upwelling—which is when nutrients from the ocean floor rise and replace nutrient-depleted surface water. 

Nutrient pollution, which occurs when there are excess emissions of nitrogen and phosphorus from sources like agriculture and fossil fuels, is another major cause of harmful algal blooms. EPA scientists predict the combined effects of climate change and nutrient pollution may cause more intense algal outbreaks to occur at higher rates across more bodies of water.

How Harmful Algal Blooms Affect Drinking Water

Image Courtesy of Clean Water Action

Algal blooms in large bodies of water have a history of negatively impacting local water quality. Wind or water currents may push algal blooms towards drinking water intakes, which spells trouble for the nearby towns and cities. Toxic chemicals from harmful algal blooms are increasingly contaminating surface water sources and drinking water treatment facilities. Water treatment facilities face a difficult task of removing toxins in a way that is both safe and cost-effective.  In the summer of 2014, for instance, Toledo, Ohio suffered a major water crisis. A massive growth of toxic blue-green algae from Lake Erie got into Toledo’s drinking water and the system had to be flushed. Half a million people were unable to drink their water, cook with it, or brush their teeth.[5]

Blue-green algae are a growing concern to water treatment companies that use surface water. Ingesting certain species of blue-green algae can cause severe health issues, including vomiting, diarrhea, fever, and headaches. Toxins from the bacteria can also negatively affect the liver and the nervous system. Treating water for blue-green algae is a complex and expensive process, which can often interfere with local water quality since it requires the increase of potentially harmful disinfectant byproducts.

Researchers from the EPA are working to find more efficient ways to remove blue-green algae in drinking water. They are adjusting where treatment chemicals are applied, modifying the types of treatment chemicals used, and experimenting with different pH levels.[6]

Quench Filtered Water Coolers Making Your Drinking Water Better

At the municipal level, reverse osmosis filtration systems are used to filter algal bloom from drinking water so that by the time it reaches the pipes in your building, it is safe to drink. A Quench bottleless water dispenser will take that potable water and make it better. When you rent from Quench, you’re getting clean, great-tasting, drinking water thanks to our full suite of advanced filtration and purification technologies that remove sediment, reduce chemical contaminants, and get rid of off-tastes and odors. Quench systems can include: quenchWATER+ filtration, advanced carbon filtration, RO filtration, ultraviolet sanitization, anti-microbial protection, food-grade tubing, and stainless-steel takes. Learn more about our filtration advantages here.

Your local water quality will vary depending on where you live. Therefore, filtration needs will vary from zip code to zip code. Quench Water Experts’ in-depth knowledge of water conditions from coast-to-coast allow us to recommend the best water filtration solution for your company. We analyze your local drinking water and customize a filtration solution to ensure your office drinking water is clean and great tasting.

There are Quench Water Experts located across the United States. Find one conveniently located near you by checking out our list of major markets here. If you have a specific question or concern about algae in your water or your local water quality in general, give your local Quench Water Expert a call at 1.888.877.0561. We’ll help you find the answers you need to make the right decisions about your building’s water supply.


[1] https://www.worldwildlife.org/threats/water-scarcity

[2] https://www.nationalgeographic.org/topics/resource-library-rivers-and-streams/?q=&page=1&per_page=25

[3] https://www.noaa.gov/what-is-harmful-algal-bloom

[4] http://biometrust.blogspot.com/2019/09/algae-and-algal-blooms_24.html

[5] https://www.cleanwateraction.org/features/harmful-algal-outbreaks-and-drinking-water

[6] https://www.epa.gov/water-research/harmful-algal-blooms-drinking-water-treatment