Algal blooms and drinking water quality: finding a solution

     The two most common complaints about drinking water are bad taste and bad smell. In both cases, the culprit could be an algal bloom. These blooms can occur in all types of aquatic systems including: ponds, lakes and reservoirs.

Understanding the complete picture of algal blooms

     Numerous types of algae grow in drinking water sources and can impact your tap water presentation and quality. Common complaints include water tasting dirty, muddy or fishy and unpleasant odors. The culprit algal bloom could be caused by an array of phytoplankton and mat-forming species that can produce over 200 taste and odor compounds. Their rapid growth will often discolor water through an increased amount of pigmented cells, resulting in colorations such as green, yellow, brown or even red. An excess of phosphates in the water, which often originate from fertilizers, wildlife or septic systems can contribute to the growth of algal blooms in fresh water.

Treating algal blooms at the source

     Algae taste and odor compounds can be difficult to treat and control in the drinking water plant. It is important to control the source of these compounds so they are not present in water coming into a plant. One approach is to proactively bind free reactive phosphorus and remove it from the water. In this process, phosphorus settles in the sediment and is not available to be used by the algae for growth. Treatment options to isolate phosphorus are extensively reviewed for safety. In addition, NSF certification is also in place, assuring algal bloom treatment is safe for use in drinking water.

     Managing algae in lakes and ponds is an ongoing concern as runoff from our lawns and fields is constantly being introduced into the system. Isolating the source of the issue and strategically targeting can provide a balance between protecting the ecosystem and ensuring source water integrity.

     Strategic reactive products can also be safely used to address the algal bloom directly. These may include SeClear Algaecide and Water Quality Enhancer or PAK 27 algaecide; both have been reviewed and approved by the EPA and certified for drinking water use. By directly targeting the source (algae) of these nuisance compounds, we don’t have to address them in the plant. Better water in = better water out!


West Bishop is the Algae Scientist and Water Quality Research Manager at SePRO Corporation. He has an M.S. in Aquatic Toxicology from Clemson University and is a Certified Lake Professional through NALMS. He blogs about algae management and other algae-related topics for StewardsOfWater.com.