When certain ecological conditions present in a water reservoir, an increase in algal compounds can occur, resulting in what some may notice and describe an earthy, musty or dirty taste and odor to the drinking water. While not aesthetically pleasing, the algal compounds that cause this type of taste and odor issue are non-toxic and not considered a risk to public health. These compounds also do not diminish the ability of a water provider to meet water quality guidelines for health standards.
While these compounds are not toxic or against any water quality guidelines for health standards or drinking water regulations, CWLP works hard to meet customer expectations for the water’s aesthetic characteristics—its taste, odor and appearance. CWLP’s water treatment process feeds powdered activated carbon to reduce taste and odor compounds in the finished drinking water. To further address the taste and odor issues, the Water Plant can increase its powder activated carbon in the treatment process and alter the depth of its raw water intake in an attempt to minimize the issue. Water Distribution can also enact distribution system flushing to move water, which can be helpful near the conclusion of taste and odor events.
What is making my water taste or smell earthy or musty?
Lake turnover, a normal event for surface water supplies, occurs in a reservoir when the water from the top of the lake to change places with the water on the bottom of the lake. With fall temperature changes, as water cools on top of the lake, it becomes more dense, causing it to sink. This dense water forces the water from the bottom to rise. Lack of water movement in a reservoir can exacerbate the turnover effect and increase the compounds that cause taste and odor issues.
Other ecological conditions and influences in a reservoir can also lead to increased algal compounds. Like temperature, the amount of precipitation or runoff, or movement of water in a reservoir can also be factors in increasing compounds. For Lake Springfield, the retirements of Dallman Power Plant Units 31, 32 and 33, which no longer pump water for cooling or discharge hot water into the lake appear to correlate with exacerbation of the higher levels of algal compounds in some instances. Dallman 4 doesn’t use lake water for cooling or discharge water into the lake.
With lake turnover or these varied ecological conditions, algal compounds from naturally occurring blue green algae result in a change in the taste and odor. The algal compounds, Geosmin and Methylisoborneol (MIB) found in naturally occurring blue green algae have been identified as the cause for recent taste and odor issues in Lake Springfield.
On September 21, 2021, CWLP presented information on status of lake turnover, impacts and potential solutions.
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Is my water safe to drink?
Yes. These algal compounds are non-toxic and do not impact drinking water safety or pose any violation of a water quality health standard or regulation. Although the water can have an off taste or odor to some described often as earthy, musty or dirty, it is safe to drink. Chilling tap water before drinking can greatly reduce taste issues.
Customers sensitive to the taste and odor issues may find drinking chilled water from a pitcher after refrigeration may be more pleasing.
What does CWLP use to make the water taste better?
The Water Plant can increase its Powder Activated Carbon in the treatment process, alter the depth of its raw water intake and conduct plant washouts to address when the issue arises. Year-round CWLP and its partners implement Best Management Practices in the Lake Springfield Watershed to reduce runoff and nutrients into the reservoir, which include those that cause algal compounds to increase.
In 2022 CWLP entered into a contract with Crawford, Murphy & Tilly, Inc. for a study of solutions for taste and odor issues. The result of this study are expected in summer 2023. This contract followed the City Council’s deferred action on CWLP purchasing and placement of circulator equipment known as, “Solar Bees,” on Lake Springfield—a measure proposed to address taste and odor issues.
Is there anything I can do to make the water taste better?
Chilling tap water before drinking can reduce taste issues for some. Adding a slice of lemon to the water sometimes helps as well. A home charcoal filter may help but it is not likely to remove the taste or odor entirely. The charcoal in a home filter uses the same material (granular activated carbon) as the water treatment plant does, which is only able to resolve most but not all, of the taste and odor causing compounds.
Where can I report water issues or ask questions?
Contact our 24-hour Water Dispatch at 217.789.2323 ext. 2 and make a report with your contact information and address or email PublicInformation@cwlp.com.
Lake Circulators “Solar Bees” Proposed To Improve Lake Water Health
On March 9, 2022 CWLP and Ixom Watercare presented information to members of the Springfield Lake Shore Improvement Association members on the use and placement of circulator equipment, “Solar Bees,” on Lake Springfield—a measure proposed to address lake turnover and resulting water taste and odor issues as occurred last late summer to fall.
From the presentation, one question asked not anticipated was if this area of the lake where the circulators would be placed would become a no wake zone. The answer to that question is no. There is not a plan to dedicate this area of the lake as a no wake zone with placement of any lake circulators.
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At the February 1, 2022 City Council meeting, CWLP and Ixom Watercare presented information on lake circulation equipment as a potential solution to alleviate impacts of lake turnover and overall improve lake water health.
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On September 21, 2021 City Council Meeting, CWLP presented information on status of lake turnover, impacts and potential solutions.
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