A big part of water quality involves identifying and eliminating microscopic bacteria – even those that are much smaller than the width of a human hair. That’s why the K. Thomas Hutchinson Water Treatment Plant uses a machine called the FlowCam Cyano in its daily water tests.
“I think of the Flowcam as a smart microscope,” said David Reed, the plant’s lab director. “The FlowCam helps us identify three different types of bacteria: cyano – which can potentially become toxic – detritus, and diatoms. Detritus can include dead organic material. Diatoms has a hard shell and can back up in our filters.”
As water accumulates nitrogen and phosphorus, algae growth increases. Algae absorbs oxygen and can even kill plants and fish. It’s critical to determine cell counts of certain kinds of cyanobacteria – such as microcystis and anabaena – to locate potentially toxic groupings.
Detection of algae and bacteria can help determine when to start maintenance efforts for filters, the run time of the filters, and the level of turbidity (particles) in water.
Cyanobacteria can lead to problems with taste and odor in the finished, treated water that arrives at ratepayers’ taps. Cyanobacteria is most prevalent in the spring and summer and in stagnant water. All cyanobacteria (if in high enough concentrations) can make humans feel sick. The plant’s usage of chlorine dioxide helps to counter that.
“We have 4x, 10x, and 20x lenses,” Reed noted. “We use the 10x to detect down to 4 micrometers to look for cyanobacteria. The FlowCam lens takes real-time pictures of bacteria and uses a red laser to detect the different kinds.”
The FlowCam automates a detection process that previously used a manual effort with a traditional microscope. The traditional method proved time consuming, tedious, prone to error, and difficult to verify.
The FlowCam deploys a red laser that measures 633 nanometers (a nanometer is one billionth of a meter) to excite microalgae fluorescence as a sample of water passes through the machine. Then, image recognition software separates the cyanobacteria from other algae in the sample and sorts the types of algae according to 40+ physical shapes.
Here’s how the FlowCam serves CUD,” said Plant Operator John Holmes. “Harmful algae and bacteria occur in the water, and we need to detect them. The Flowcam helps us understand the extent of the concentration so we can take steps to eliminate algae and bacteria and preserve water quality. It also helps us plan when to increase our usage of chemicals.”