The City of Akron Public Utilities Bureau ("Water Department") has determined the taste and odor occurrence in the local drinking water supply since mid-December appears to be a result of compounds released from algae and soil bacteria. Due to the tremendous amount of snowmelt, rainfall and runoff into the upper Cuyahoga River watershed during late November, and possibly aggravated by the rapid forming ice cover on Lake Rockwell, a compound found in naturally occurring blue green algae has been identified in elevated levels. In addition, another compound found in actinomycetes, a common soil bacteria, is present. The two naturally occurring compounds, 2-methylisoborneol (MIB) and Geosmin, are normally present in drinking water at very low levels and many times cannot be detected at all with currently available technologies. Unfortunately, these compounds are very powerful taste and odor causing compounds that can be detected by humans at levels of less than 10 parts per trillion (ppt). As a comparison, one part per trillion is approximately equal to one drop of water in 15 million gallons of water or one inch in 16 million miles.

With the events of late November, large quantities of MIB and to a lesser degree, Geosmin, were washed into the lakes, blue green algae experienced a growth spike due to an increased nutrient supply washed into the lake, and disturbed lake and river bottom sediments.

MIB is commonly found in the bottom layers of lakes, concentrated there from the decomposition of the blue green algae found in lakes and is often described as imparting a musty taste or odor to the water. Geosmin is the same substance that gives soil its characteristic soil odor. Many customers have described the recent taste and odor occurrence as being a musty, earthy taste or odor. Both MIB and Geosmin have no known health effects and are not regulated with any health standards. All water quality tests indicate the drinking water is meeting all EPA standards and is safe to drink and use.

The Water Department has utilized several different strategies to combat this taste and odor episode. The use of oxidants at the start of the treatment process was discontinued as it was thought to add to the intensity of the problem due to additional destruction of the taste and odor causing bacteria and algae, releasing the MIB and Geosmin compounds before the bacteria and algae could be removed by the water treatment process. To assist in the removal of the taste and odor causing compounds additional carbon in a powdered form has been and continues to be added to the water. The powdered activated carbon is used to remove organic matter and thus the cause of the offensive tastes and odors. The carbon acts like a sponge in absorbing the organic materials that cause the tastes and odors.

Laboratory analyses of the water have indicated MIB levels were originally at high levels in the raw water and treated water. Geosmin levels have been low in the raw water, and below detection levels in treated water. These compounds can be detected by humans at levels as low as 4-5 parts per trillion. The water in Lake Rockwell had levels of 250 ppt for MIB on December 28, dropping to 42 ppt as of January 23. Geosmin levels during the same timeframe dropped from 14 ppt to 6.8 ppt. In the upper watershed in Geauga County, MIB levels in the East Branch Reservoir on January 10 were 1100 ppt, while less than detection (<5 ppt) at LaDue Reservoir. In the upper watershed in Portage County, MIB levels in the Cuyahoga River at SR 303 on January 16 were 58 ppt. At the higher levels of MIB in the raw water, it is virtually impossible to remove all of the MIB taste and odor causing compound through the conventional water treatment process.

MIB levels in the treated water were 260 ppt on December 28, dropping to 16 ppt on January 23. Geosmin levels in the treated water during the same timeframe dropped from 8 ppt to below detection (<5 ppt). Changing the application point of powdered activated carbon to the water intake and changing the type of powdered activated carbon from bituminous to lignite appears to be effective in reducing the MIB levels by 65-75%.

MIB levels in the distribution system are being monitored in addition to the raw and treated water. MIB levels in the water distribution system follow the treated water levels on a delayed basis. When noticeable improvements are achieved in the treated water, the improvements take a few days to be reflected across the distribution system due to travel time. For example, the MIB levels in the distribution system on January 10 averaged 120 ppt MIB compared to the treated water level of 68 ppt MIB, and on January 23 the distribution system level averaged 26 ppt MIB compared to the treated water level of 16 ppt MIB.

With less precipitation and runoff, the water quality in the lakes is improving. The clarity of the water is improved indicating there is less material (silt and algae for instance) in the water. This also indicates that bottom sediments that may have been disturbed with the heavy flows through the lakes, have settled down. Additionally, with the colder temperatures, biological activity is slowing. This will lead to lower levels of the odor causing bacteria and algae through the winter months. Also, Lake Rockwell received an algae control treatment on January 18. All of these factors are leading to an improvement in the taste and odor of the water.

Customers are advised to chill water before consumption as the colder the water is the less noticeable the taste and odor appears.

The Water Department continues to consult with drinking water taste and odor experts in an effort to resolve this situation and be better prepared for future situations. The Water Department also continues to be in contact with the Ohio EPA, Akron Health Department and Summit County Health Department during this situation.

The Water Department serves approximately 300,000 Summit County residents in all or part of the cities of Akron, Stow, Tallmadge, Fairlawn, Mogadore, Cuyahoga Falls and Hudson, along with parts of the townships of Bath, Boston, Copley, Coventry, Springfield and Twinsburg.

January 13, 2006

Update

 What is the Akron Public Utilities Bureau doing to fix the water taste and odor situation?

• We are monitoring the odor level of raw water coming into the Water Plant and water after treatment. Odor monitoring assists water treatment staff in making adjustments to the treatment process.

• We are sending samples of raw water, treated water at the treatment plant, and water in the distribution system for analysis of the odorous compound (MIB) levels. These analyses assist the Akron Public Utilities Bureau staff in making adjustments to the treatment process and distribution system.

• We are consulting with other water utilities and industry experts to gain knowledge on dealing with and resolving this situation.

• We have constructed a temporary facility at the water treatment plant to add powdered activated carbon (PAC) at the water intake. This installation will give the PAC more time to absorb the odor causing compound before the treatment process chemicals are added.