The city of Lawrence isn’t the only place under siege by an aquatic menace that’s causing a funky taste in the drinking water.
Water utilities up and down the Kaw River have reported similar problems. And, public health warnings and advisories have been issued for seven bodies of water across the state.
The culprit: blue-green algae blooms.
As the state’s aging reservoirs fill up with nutrient-rich sediment, these algae blooms aren’t expected to go away anytime soon, scientists say.
“I suspect the water quality issues are going to get more frequent and more severe,” said Don Huggins, an aquatic ecologist for the Kansas Biological Survey. “You’re not going to see it improve because the water body holding it is an aging reservoir, filling with nutrients and filling with sediment.”
A good growing year
Blue-green algae, which has the scientific name of cyanobacterial blooms, isn’t entirely evil. The plant is a natural component of all aquatic ecosystems, surviving on Earth for more than 3 billion years, according to Tom Langer, who is the Kansas Department of Health and Environment’s director of the Bureau of Environmental Health.
The recent problem is a result of a good growing year.
A wet spring and early summer washed nutrient-rich water runoff into the state’s reservoirs. That was followed by calm, sunny days where temperatures topped out above 100 degrees. Water temperatures went up, creating ideal growing conditions for algae.
“Low wind conditions combined with hot weather usually are all it takes in most lakes with high phosphorus for blooms to thrive,” said Marvin Boyer, a lake water quality program coordinator with the U.S. Army Corps of Engineers. Boyer responded to questions through e-mail.
Blue-green algae is only a public health concern during growth spurts like this summer, when it multiplies rapidly creating what is known as algae blooms.
These algae blooms leave high concentrations of toxins in the water, which can cause nausea, vomiting, diarrhea, skin rash, eye irritation and respiratory distress in humans. For pets and animals, drinking the water can cause serious illness and death.
When toxins reach that level, the KDHE issues warnings for people and pets to stay out of the lakes.
From lake to water glass
The harmful toxins are filtered out when water is treated, which makes the reservoir water safe to drink by the time it comes out of the tap.
However, there is no solution for eliminating the less than pleasant smell and taste that comes from dying blue-green algae.
Lawrence residents started noticing the odd taste about a week and half ago. The dead algae plants aren’t coming from Clinton Lake, said Jeanette Klamm, projects manager for the city of Lawrence’s utilities department. The source is the Tuttle Creek Lake, near Manhattan, where an expansive algae bloom is present. Water released from the dam sends the dead algae downstream to Lawrence.
How long Lawrence residents will taste the water depends on the life cycle of the algae plants. In the meantime, Klamm said the city is trying to push as much of the water supply as it can through the Clinton treatment plant.
As the weather warms back up and more water is used, the funky tasting water will return as the city resorts to the Kaw River Water Treatment Plant to meet the demand.
At lower algae levels, Klamm said the city can mask the taste and odor problems by boosting the amount of carbon used in treatment. But eventually, the city reaches a limit on how much carbon is used. Too much carbon clogs the filters.
Managing the problem
This latest battle with blue-green algae has prompted the city to look back to see how frequently taste and odor problems are occurring.
“Is it increasing, or are we paying attention to it more?” Klamm asked.
The KDHE doesn’t have historical data on how many public health warnings have been issued over the years because of algae blooms in bodies of water.
By working to lower the amount of nutrients entering the reservoirs, the severity and regularity of algae blooms can be reduced, said the U.S. Army Corps of Engineers’ Boyer.
That would entail preventing erosion, fixing leaking septic systems, minimizing animal waste that enters waterways, planting buffer zones and applying fertilizer more wisely.
More drastic measures, such as dredging, will have to be taken in half a century when the state’s reservoirs reach their life expectancy. That day could come sooner than expected as reservoirs such as Clinton Lake are filling with sediment faster than engineers had anticipated, said Huggins, of the Kansas Biological Survey.
“In 40 to 60 years, the major issue won’t just be quality but quantity. You’ll pay more for less,” he said.
Huggins said he believes elected officials need to start preparing now for that inevitability.
“I think we have reached that time where we will have to begin to plan for the future,” he said. “We can’t just say it is 20 years out.”