A. PWS Source and Treatment Information Review History, and Overview of Existing Treatment Processes 1. Identify all raw and finished water sources connected (directly) to the treatment plant and list supplying systems and/or emergency interconnections that can be used as alternatives. 2. Describe any current cyanobacteria monitoring and response plan that may be in place. 3. Provide a detailed water treatment schematic and description of the water treatment process, relevant to intra and extracellular toxin removal. B. Establishing Triggers for Optimization Based on Raw and Finished Water Quality Identify changes in raw water or in-plant treatment processes that may indicate HAB event is developing or occurring. Triggers could involve the following parameters: 1. Cyanotoxin-production genes, pH, phycocyanin or chlorophyll-a concentration, cyanobacteria or phytoplankton identification and cell counts, remote sensing satellite or hyperspectral imagery data. 2. Above normal chemical demands (e.g., coagulants, PAC, chlorine), shorter filter run times or increased solids loading. Such changes should be monitored, and source water conditions investigated to determine the cause. This task will include determining relevant monitoring parameters, trigger thresholds for PWS actions to be made under various raw and finished water conditions. C. Source Water/Reservoir Management Strategies Consideration of the following source water management strategies: 1. Opportunities to minimize cyanotoxins entering from the intake by running on storage temporarily or may be able to avoid a short-term HAB event. 2. Switch sources or blend sources (e.g., different reservoir, interconnections with other systems, ground water). 3. Nutrient reduction strategies for inputs into reservoir (e.g., selective pumping from stream when nutrients are low. 4. Source water protection strategies (shoreland protection, addressing septic system failures, improved stormwater treatment). 5. Dilution and flushing of reservoir system with higher quality water. 6. Phosphorus inactivation treatment or hypolimnetic aeration (oxygenation) and reservoir mixing/circulation.
