Jun 15, 2021 2:34:47 PM / Brooke Loeffler /

Which Deicing Ingredients Affect Algae Growth?

When looking at the relationship between deicers and the environment, most people simply look at the effects on roadside plant health. However, every substance applied to our roadways enters our waterways as well. When choosing environmentally friendly deicers, we also need to consider how road treatments affect our rivers, streams, lakes, and oceans. Here, we will learn more about algae growth, what causes harmful algae blooms, and which deicing ingredients contribute to these conditions.

Which Deicing Ingredients Affect Algae Growth?

A Closer Look At Algae

Algae is a group of photosynthesizing organisms that grow in both fresh and saltwater. They vary widely in size (from microscopic to kelp size) and color (i.e. blue-green, yellow, brown, pink, red). Algae is a natural piece of the aquatic food web and is present in almost all bodies of water. The health of our waterways is protected by a delicate balance of these microorganisms, dissolved oxygen, and nutrients. Algae growth is one of the most telling indicators of a problem with this balance. 

Harmful Algae Blooms (HABs)

An overgrowth of microscopic algae is called a bloom. Algae will over-produce when they experience an increase in nutrients/organic mass in the water, warmer temperatures and/or slower water flow. Some types of algae create dangerous conditions when they bloom.

They can release a variety of toxins:

  • Neurotoxins- harm the brain and central nervous system
  • Dermatoxins- harm skin and respiratory systems
  • Hepatotoxins- harm the liver

Being exposed to HABs can be deadly for humans, pets, and other wildlife.

They use up dissolved oxygen in the water:

HABs over consume dissolved oxygen in the water as they feed on excess nutrients. This is referred to as Biochemical Oxygen Demand (BOD) and is a measurable indicator of waterway health. Aquatic animals rely on dissolved oxygen to live and the increased BOD causes massive fish kills and alarming dead zones.

A Growing Problem

HABs are occurring more frequently and becoming more widespread. According to the Environmental Protection Agency (EPA) “harmful algal blooms are a major environmental problem in all 50 states.” The largest HABs may grow at deposit sites like the Gulf of Mexico, however they are also growing in our lakes, streams, ponds, and favorite swimming holes nationwide.

What Causes Harmful Algae Blooms?

Algae growth naturally increases in warmer and slower moving water, making late spring, summer, and early fall the most prolific algae seasons. However, one remaining factor can take natural seasonal algae growth and create hazardous conditions.

What causes harmful algae blooms

Nutrient Pollution

The most common cause of HABs is eutrophication, or an over-enrichment of nutrients in the water. When too many nutrients enter the waterways, algae begin to glut themselves and use up the dissolved oxygen in the water as they feast.

Under healthy conditions, decaying plant life and natural waste from aquatic animals provides the right amount of nutrients in a waterway. But when runoff carries carbohydrates, organic waste, and fertilizers (especially nitrogen and phosphorus), then excessive amounts of consumable nutrients enter the water. Algae uses these carbohydrates and nutrients to build more cells, and even store energy to survive periods of darkness with no sun for photosynthesis. 

Which Deicing Ingredients Cause Nutrient Pollution?

Deicers can contain a variety of ingredients that interfere with water’s ability to freeze. These ingredients range from chloride salts, acetates, glycols, and agricultural byproducts. Deicer manufacturers sometimes combine some of these ingredients together to achieve the performance they are looking for. Let’s take a look at which deicing ingredients contribute to nutrient pollution in our waterways.

Agricultural Byproducts

Some deicers use agricultural byproducts (ABPs) such as beet pulp/juice, grape skins, fermented corn byproducts, and even lactose and fermented whey from cheese making.

While re-purposing agricultural waste sounds like an environmentally sound practice, over-depositing carbohydrates into the ecosystem greatly harms waterway health.

A study conducted by the Michigan Department of Environmental Quality has found adverse effects of agricultural byproduct deicers on their many lakes and streams. They found that:

“de-icing products derived from ABPs have the potential to adversely affect water quality if allowed to enter surface waters. These products often contain high levels of organic materials which exert a high biochemical oxygen demand (BOD) when broken down by microorganisms in an aquatic environment. This results in reduced in-stream levels of dissolved oxygen (DO), which is necessary for the survival of aquatic life. Fish kills, impaired biological communities, and noxious growths of bacterial slimes can result from elevated BOD and reduced levels of DO in streams and lakes.

Some ABP deicers have the potential to greatly impact DO concentrations in surface waters, as they may contain many times the amount of BOD found in strong wastes like raw sewage.”

A study conducted by the State of Idaho also found that:

“organic matter, such as CSB [concentrated sugar beets] used as a corrosion inhibitor, can increase biochemical oxygen demand in receiving waters, depriving aquatic life of oxygen.”

They also noted that:

“agricultural byproducts patented for use as roadway deicing and anti-icing        agents, including the liquid residue of fermented corn byproducts...has been shown to cause ‘eutrophication of water, which will result in the proliferation of noxious aquatic plants, especially blue green algae,’ reducing water oxygen levels.”

Carbohydrates and Algae-01

Glycols (Ethylene and Propylene Glycol Solutions)

Deicers containing glycol are most commonly used to deice aircraft. Because glycol is a sugary alcohol, a harmful microbial feast is triggered when it reaches waterways. The Federal Aviation Agency (FAA) has admitted that: 

“ethylene glycol is toxic to aquatic and mammalian organisms” and that “propylene glycol will remain in the environment longer than ethylene glycol and will consume more oxygen while it is being broken down. Therefore, it can still be harmful to the environment.” 

Since discovering these risks, the FAA has been testing methods to reduce these effects “using various combinations of bacteria, nutrient mixes, enzyme mixes, and ultrasonic stimulation.” 

Ice Slicer: A Water Friendly Deicing Solution

Ice Slicer is a powerful and environmentally friendly deicer containing a blend of naturally occurring complex chloride salts. Of all deicing ingredients, chloride salts have the lowest impact on BOD levels and do not introduce carbohydrates and organic matter into our water (see graphic above). Our deicer is harvested from a subterranean, Jurassic mineral deposit and naturally contains over 60 trace minerals. Ice Slicer does not contain any harmful chemical additives, dyes, acetates, glycols, or agricultural byproducts that lead to nutrient pollution and harmful algae growth in our precious waterways.