At Lutra, we are dedicated to enhancing the safety and efficiency of water treatment processes. Recently, our team, led by John Church, collaborated with the Kapiti Coast District Council to develop an innovative method for monitoring and predicting cyanobacteria, and therefore cyanotoxin, risks in water treatment plants. This initiative addresses the critical need to monitor, understand and predict the risks associated with the presence of cyanobacteria and algae in water sources.
The primary goal of this project was to create a reliable system to monitor when cyanobacteria and algae are entering the water treatment plant, whilst also providing insights as to the health of the waterway and predicted upstream presence of algae within the waterway. This predictive capability is essential for maintaining water quality and ensuring the safety of the water supply. Our approach involved working closely with the onsite operations team, the development of a sampling plan and the installation of instrumentation to establish a robust monitoring system.
The monitoring system consisted of two advanced sensors capable of directly measuring the concentrations of algae and cyanobacteria entering the plant. These sensors, spectrofluorometers from TriOS, measure phycocyanin and chlorophyll-a by emitting light and analysing the fluorescence at specific wavelengths. Although the sensors do not identify species or count organisms, they provide crucial indicators of the empirical presence and concentration of these potentially harmful microorganisms.
To enhance our predictive capabilities, we integrated the sensor data with other online data sources using Lutra ID (Infrastructure Data). This integration allowed us to correlate the presence of cyanobacteria and algae with various environmental factors, such as weather conditions and water chemistry. By analysing these relationships, we developed a predictive model that helps us anticipate potential risks and take proactive measures.
The implementation of this monitoring system has yielded benefits. For the first time, Kapiti’s operators can directly see what is entering the plant and predict future occurrences. With the support from Automation For Industry (AFI) we developed an advanced process control algorithm for the plants PLC, which actively controls the powdered activated carbon dosing at the plant to minimise cyanotoxin risk. Work on taste and odour predictive control is ongoing.
Not only has this automation yielded benefits and cost savings, it has allowed the Kapiti team to significantly improve their ability to proactively monitor and manage the risk.
This capability is particularly important as cyanobacteria and algae growth are no longer confined to the summer months; they can occur during winter and other unexpected times.
Our system has proven to be a powerful tool for managing plant operations. It provides real-time data that helps operators adjust dosing levels and other treatment parameters, without the need for constant manual inspection or delayed results from laboratory testing. This automation not only improves efficiency but also increases visibility and therefore reduces operational costs, in this case KCDC is expecting to save around $40,000/year in PAC chemical costs.
The monitoring system is versatile and can be adapted to other water treatment plants. By understanding the variations in conditions of a water source, such as temperature, drought and chemistry, and visualising this data, the system can provide valuable insights and predictions. It is this adaptability makes it a valuable tool for water treatment facilities worldwide.
Our collaboration with the Kapiti Coast District Council has resulted in a significant advancement in the monitoring and prediction of cyanotoxin issues – relating these directly back to an operational level. This project exemplifies our commitment to innovation and excellence in water treatment. We are excited to share our findings and continue to develop solutions that enhance the safety and efficiency of water treatment processes.
For more detailed insights, Cassandra Yang (Lutra) and Bruce Nesbitt (KCDC) will be presenting this project at the upcoming WIOG conference in Nelson.
Why not attend or reach out to us for further information and assistance with cyanobacteria or any other water treatment challenges.
