What is algae?

Algae is a single-celled plant that occurs naturally in all surface water. It can be green, blue-green, brown, red, or pink. Algae in water is not a concern normally, as it is present in all surface water, but at certain times it can grow explosively, a condition called bloom. Blooms occur when algae in water has reached the proper temperature and sunlight to reproduce exponentially, usually in the warmest part of summer. The most common kind of algae found in water is cyanobacteria.

Are there health risks associated with consuming algae?

According to Falconer’s “Algal Toxins in Seafood and Drinking Water” blooms of algae in water are frequently associated with poisoning and even death in livestock and humans. Cyanobacteria in very high concentrations can cause liver damage, and even though this is unlikely to occur in drinking water, algae in water can cause diarrhea and stomach cramps. Also, even low levels of algae in water can irritate the skin and eyes when used for showering or swimming.

Under what conditions does algae grow?

Algae blooms occur when they have plenty of sun and appropriate temperature in the water, which means that still, shallow water will bloom where a stream will not normally. Since many drinking water systems use a reservoir to draw their water from, algae can enter your house through your taps. Algae may also grow in drinking glasses if they are not properly cleaned.   Be sure to regularly clean your drinking bottles with a dilute bleach solution.

How could it get into drinking water?

Many towns and cities use reservoirs to deliver drinking water to homes.  These reservoirs can be a great host for algae.  High concentrations of nitrogen and ammonia, common commercial fertilizers, can cause an algal bloom to occur. This can mean that a cracked well casing could allow algae to enter even an artesian system.

How can I remove algae in water?

Algae in water can be controlled through the use of algaecides, but this is less than ideal as even in their decomposition they can release toxins. Ideally they can be avoided at the reservoir level by installing draw off pipes deep enough to avoid the algae. On a household level, a filter is the easiest and quickest way to make sure you are not drinking tiny plants with your water.