The Safe Drinking Water Act (SDWA) requires EPA to publish a list of substances that could potentially be of concern and warrant further study, known as the Contaminant Candidate List (CCL). Cyanotoxins were listed on the third CCL as a group and were also included on the proposed CCL4. EPA’s evaluation is expected to focus on microcystins, and cylindrospermopsin.
In June 2015, EPA issued ten-day “health advisories” for microcystins and cylindrospermopsin. Health advisories indicate levels of contaminants in drinking water below which there are expected to be no health impacts. EPA has provided two different ten-day health advisory levels for each compound as shown below– one for children under six years old and another for children over six years old and adults.
- Microcystins: 0.3 µg/L for children under six years old and 1.6 µg/L for children over six years old and adults
- Cylindrospermopsin: 0.7 µg/L for children under six years old and 3.0 µg/L for children over six years old and adults
Researchers, regulators and utility managers will use these health advisories as they consider possible regulations and/or other management practices in the future.