Public Water Systems Susceptible to Harmful Algal Blooms
If a surface water source is found to be vulnerable, a system specific Cyanotoxin Management Plan (CMP) must be prepared to guide operators on how to effectively monitor and treat source water, raw water, and finished water to prevent cyanotoxins from reaching the distribution system. The purpose of the CMP is to establish strategies for monitoring and responding to HABs in its source water.
Steps and topics for inclusion in the CMP are outlined below and are explained in-depth later in this document, along with listed information resources, examples, and links for further research.
Developing a Cyanotoxin Management Plan
Create Water System Overview
- Identify and describe source water options for your system.
- Describe current treatment processes and/or include a treatment schematic.
- Determine whether current processes are available to adequately address cyanotoxins. If not, evaluate whether supplemental treatment or operational changes (e.g., oxidants, switch to groundwater source) might be needed during bloom season.
- If source water is vulnerable and existing treatment is frequently challenged by cyanotoxins, consider whether long-term treatment enhancements are needed
- For all of your available source waters, list any routine source water quality monitoring that your water utility conducts or has recently conducted
Detail Source Water Assessment and List Potential Vulnerabilities
- Establish a system-specific monitoring schedule, sampling methods, and compile resources to aid identification of bloom indicators in your source water.
- List potential mitigative and control measures; physical/ chemical/ biological techniques to reduce HABs in source water.
Monitoring Raw water for cyanotoxins
- Create an outline of sampling procedures to be followed in the event of confirmed presence of bloom indicators in your source water
- Establish monitoring/sampling schedule for cyanotoxins
- Determine which form of toxin analysis is feasible for your utility.
- List potential mitigative and control measures; Physical/ chemical/ biological techniques to reduce cyanotoxins in raw water, (e.g., treatment options)
Monitoring finished water for cyanotoxins
• Create an outline of finished water monitoring procedures to be followed in the event of confirmed cyanotoxins in raw water.
Systems unequipped to treat cyanotoxins will need to implement treatment improvements (if not already upgraded) to prevent cyanotoxins in finished water.
- Create step by step of contingency plan in the event of confirmed MCL exceedance of cyanotoxins in finished water.
- Further treatment improvements
- Emergency response plan to control/ isolate contamination
- Alternate water sources/ partner utilities
Draft system specific public notifications in event of vulnerability (consumer confidence reports), confirmed MCL exceedance of cyanotoxins in finished water (templates provided) Long Term Strategies Documentation and reporting, working with state agencies and other utilities to mitigate and prevent future blooms.
Documentation and reporting, working with state agencies and other utilities to mitigate and prevent future blooms.