Algae control more difficult due to mixer equipment failures
As City water department staff continually works to mitigate algae at Hudson Lake known to impact the taste and odor of our water, vandals have made the job more difficult by damaging several of the lake’s mixers — also known by their brand name, SolarBees — that churn the lake water and prevent algae from forming, Water Utilities Director Terry Lauritsen said recently.
The City-owned Hudson Lake is a popular hotspot for outdoor enthusiasts during the summer — fishing, boating, kayaking and paddle boarding are all allowed.* But summertime can also pose challenges in moderating algae formation in the City’s primary source of water supply.
In fact, at some point during nearly every summer, many water customers will notice an odd or “fishy” taste and odor in the water coming from their taps, although not everyone can detect it. The unpleasantness is caused by organic compounds in the lake known as Geosmin and Methyl-Isoborneol (MIB) getting into the water system.
“It isn’t harmful — it’s not even measured by water regulating bodies — but both compounds can produce an ‘earthy,’ ‘fishy,’ or ‘dirt-like’ taste and odor, which, of course, can be unpleasant for people who can detect it,” said Lauritsen. “The compounds are released by algae constituents in the lake and can be difficult to manage when temperatures fluctuate significantly or we receive heavy rains that bring nutrients into the lake.”
Algae control
The Water Utilities Department employs a couple of methods to help reduce the formation of these compounds, one of which is applying an environmentally-friendly algaecide to the lake. This comes at a whopping cost of $12,000 per treatment, however, and takes about a week to take effect.
“It’s always a race to try to apply the algaecide before the compounds enter the system, which of course is costly and can be difficult to predict,” Lauritsen said. “We haven’t always been successful in getting the treatment applied quickly enough to keep these compounds from entering the system. Fortunately it only takes a week or two for them to work their way through the entire system, at which time the odor and taste of the water returns to normal.”
But controlling algae formation this season has been a bit more of a challenge, Lauritsen said, due to damages to the lake’s SolarBees, which are large apparatuses placed strategically throughout the lake to churn the water to reduce the formation of algae.
“These mixers are responsible for basically turning the water over from bottom to top so that algae formation is greatly reduced,” said Water Plant Superintendent Larry Thompson. “Unfortunately, we’ve had several of these units damaged or destroyed by vandals, so we’ve been in a constant state of repair since the summer started.”
Thompson said that normally, the lake has 10 SolarBees working to keep the water turned. Earlier this summer, the lake was down to two working units, though five are currently operational.
“So basically we are down five units, some of which may need extensive repairs,” Thompson said. “So far we’ve been able to repair them ourselves, but that will probably not be the case with these.”
Vandalism: Why?
Thompson said the damage is occurring both through intentional vandalism and by people trying to create fisheries attached to the SolarBees so they can increase their chances of catching fish in those areas.
“What’s happening is that people attach brush to the bottoms of the SolarBees to attract fish,” Thompson said. “In the process, they drag them around, and, at least in one case, deliberately break parts of the unit so they are no longer operational.
“This diminishes our ability to manage the formation of geosmin and MIB in the lake and, while not harmful, it has resulted in more of these compounds entering the system than we would have had in a typical summer.”
Thompson said the vandalism has not only resulted in water customers detecting more algae in the water this summer, it has resulted in added expense due to algaecide application, not to mention the cost for repairs and/or replacement of the remaining three SolarBees.
“We don’t have a cost estimate for possible repairs yet, but a new unit costs roughly $60,000,” he said.
Tampering with the SolarBees is also illegal, Lauritsen said.
“Altering these units in any way is a crime, so we need for everyone who is doing this to stop,” Lauritsen said. “We’re asking anyone who sees anything suspicious or has information about these vandalisms to contact the Bartlesville Police Department.”
Anyone detecting an odor in their water is encouraged to call the Water Utilities Department at 918.338.4104 so the system can be flushed in that area.
Staying on track
Between the working SolarBees and the algaecide treatments, the formation of geosmin and MIB has been greatly reduced, Thompson said.
“We test the water weekly during the summer months, and right now our numbers are looking very good,” he said. “We’re in the single digits. To put that into perspective, people who are sensitive to the compounds can detect them at around 40, and at one point earlier this summer, we were over 100. So we are very happy with single digits.”
Though treatment of the lake’s water varies in response to weather and other environmental conditions, Lauritsen is hopeful the numbers will remain on track until the remaining SolarBees can be repaired.
“We’re hoping that getting the word out there that destruction of these units is not only a crime but also has so many other, unintended consequences will help stop this from happening,” Lauritsen said. “Hudson Lake is one of our most valuable and important resources, and we all need to do our part in protecting it.”
Anyone who sees suspicious activity or has information about vandalisms at Hudson Lake or any other crime is asked to contact the police department at 918.338.4000.
*Swimming is not permitted at Hudson Lake.