Algae is the Culprit behind Drinking Water Taste and Odor Issues

Increasing amounts of algae in Beaver Lake may lead some customers to detect taste or odor in their drinking water right now. What is important to remember is that the water is safe to drink, according to officials with Beaver Water District (BWD).

“Just about every year around Labor Day, conditions in Beaver Lake can favor the rapid growth of algae,” said James McCarty, Manager of Environmental Quality for BWD. “When algae die, they may give off compounds that can cause unpleasant tastes and smells in drinking water. One of those compounds, 2-methylisoborneol or MIB as we refer to it, is the main culprit at the moment. We sample for it regularly so that we can stay on top of the condition of our source water.”

In late summer on Beaver Lake, there’s just the right amount of sunlight, heat, and nutrients to promote a lot of algal growth.  MIB is released by certain algae as part of their normal life cycle. “MIB is detectable to people at different levels,” McCarty added. “The standard threshold number is 5 parts per trillion, which is roughly equal to one drop in four Olympic-sized swimming pools.  Some people may not notice any taste and odor until the levels are much higher. Others may never notice it.”

Many customers will attribute these taste and odor issues this time of year with lake turnover, which typically happens in October. As temperatures begin to cool, the water in the lake will mix from top to bottom. This can cause compounds to rise from the bottom of the lake to the top. Various organic compounds may then be introduced into the raw water supply and this frequently leads to taste and odor problems which are in addition to the one we are experiencing now.

Taste and odor issues occur as a result of environmental conditions but human actions can be a contributor, officials said, adding that they want customers to understand the cause of taste and odor and be proactive about taking care of Beaver Lake. To help keep the lake free of too many nutrients, don’t over fertilize lawns and contain sediment and dirt on construction sites with silt fencing.

The good news is that taste and odor at the tap can be minimized in a variety of ways. For instance, chilling water and/or adding some lemon to the water will help. In addition, some people use carbon filters – the type used in water pitchers or attached to faucets.

“These taste and odor issues are not unique to our area,” McCarty said. “It’s just a seasonal event. It may last a few weeks. The timeframe varies. BWD can’t control nature. However, we want to assure our customers that, no matter how short or long the duration of the event, the water is safe to drink.”

BWD’s mission is to serve our customers’ needs by providing high quality drinking water that meets or exceeds all regulatory requirements and is economically priced consistent with our quality standards. BWD supplies clean, safe drinking water, sourced from Beaver Lake, at the wholesale price of $1.31 per thousand gallons to Fayetteville, Springdale, Rogers, and Bentonville. These cities in Northwest Arkansas then pump, store, distribute and resell the water to their customers — more than 320,000 people and industries in their cities and surrounding areas. For more information, contact Amy Wilson, Director of Public Affairs, at or link directly to this taste and odor fact sheet at