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Availability of Health Effects Support Documents and Drinking Water Health Advisories for Cyanobacterial Toxins; and a Support Document Containing Recommendations for Managing Cyanotoxins in Drinking Water

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Environmental Protection Agency (EPA).


Notice of availability.


The Environmental Protection Agency (EPA) announces the release of Ten-Day Health Advisories (HAs) for two cyanobacterial toxins, microcystins and cylindrospermopsin. EPA also announces the release of Health Effect Support Documents (HESDs) for three cyanobacterial toxins: Microcystins, cylindrospermopsin, and anatoxin-a. The HESDs constitute a comprehensive review of the published literature on the chemical and physical properties of these toxins, the toxin synthesis and environmental fate, occurrence and exposure information, and health effects. The HESDs are used to develop HAs. Based on the reported occurrence, toxicology, and epidemiology data, EPA found there are adequate data to develop HAs for microcystins and cylindrospermopsin, but inadequate data to develop an HA for anatoxin-a. EPA's HAs provide states, drinking water utilities and the public with information on health effects of microcystins and cylindrospermopsin, analytical methods to test for cyanotoxins in water samples, and treatment technologies to remove Start Printed Page 34638cyanobacterial toxins in drinking water. Additionally, EPA announces a support document for states and utilities to assist them as they consider whether and how to manage cyanobacterial toxins in drinking water. The recommendations in this document are intended to assist public drinking water systems (PWSs) manage the risks from cyanobacterial toxins in drinking water, including information and a framework that PWSs can consider in their cyanotoxin risk management efforts.

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For information regarding the HAs or HESDs: Lesley D'Anglada, Office of Water, Health and Ecological Criteria Division (4304T), Environmental Protection Agency, 1200 Pennsylvania Avenue NW., Washington, DC 20460; telephone number: (202) 566-1125; email address: For information regarding recommendations for cyanotoxin management in drinking water: Hannah Holsinger, Office of Water, Office of Ground Water and Drinking Water (4607M), Environmental Protection Agency, 1200 Pennsylvania Avenue NW., Washington, DC 20460; telephone number: (202) 564-0403; email address:

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I. General Information

A. How can I get copies of this document and other related information?

1. Electronic Access. You may access this Federal Register document electronically from the Government Printing Office under the “Federal Register” listings at FDSys (​fdsys/​browse/​collection.action?​collectionCode=​FR). The Health Effects Support Documents and the Health Advisories for the cyanobacterial toxins are available on EPA's Web site at​drink/​standards/​hascience.cfm. The Recommendations for Public Water Systems to Manage Cyanotoxins in Drinking Water document is available on EPA's Web site at​nutrient-policy-data/​guidelines-and-recommendations.

II. What are cyanobacterial toxins and how are they produced?

Algae and cyanobacteria are natural components of fresh water; however, under favorable conditions, they can rapidly multiply causing “blooms.” Some cyanobacterial species can produce toxins (cyanotoxins) at levels that may be of concern for human health. These cyanobacterial toxins are of particular concern because of their potential impacts on drinking water and the potential to affect human health.

III. What are EPA's Health Advisories?

Under the Safe Drinking Water Act, EPA may publish Health Advisories (HAs) for contaminants that are not subject to any national primary drinking water regulation. 42 U.S.C. 300 g-1(b)(1)(F). EPA develops HAs to provide information on the chemical and physical properties, occurrence and exposure, health effects, quantification of toxicological effects, other regulatory standards, analytical methods, and treatment technology for drinking water contaminants. HAs describe concentrations of drinking water contaminants at which adverse health effects are not anticipated to occur over specific exposure durations (e.g., one-day, ten-days, several years, and a lifetime). HAs also contain a margin of safety to address database uncertainties. HAs serve as informal technical guidance to assist federal, state and local officials, as well as managers of public or community water systems in protecting public health when emergency spills or contamination situations occur. They are not regulations and should not be construed as legally enforceable federal standards. HAs may change as new information becomes available.

IV. Information on EPA's Ten-Day Health Advisories for the Cyanobacterial Toxins, Cylindrospermopsin and Microcystins

Today, EPA is making available the HA values for the cyanobacterial toxins microcystins and cylindrospermopsin. EPA recommends 0.3 micrograms per liter for microcystins and 0.7 micrograms per liter for cylindrospermopsin as levels not to be exceeded in drinking water for bottle-fed infants and young children of pre-school age. For school-age children through adults, the health advisory values for drinking water are 1.6 micrograms per liter for microcystins and 3 micrograms per liter for cylindrospermopsin. The HA values are based on exposure for ten days.

V. Information on EPA's Support Document To Assist States and Utilities in Managing Cyanobacterial Toxins

EPA also announces the release of a cyanotoxin management document that is a companion to the HAs for microcystins and cylindrospermopsin. The document is intended to assist PWSs that choose to develop system-specific plans for evaluating their source waters for vulnerability to contamination by microcystins and cylindrospermopsin. It provides information and a framework that PWSs and others (as appropriate) can consider to inform their decisions on managing the risks from cyanotoxins to drinking water.

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Dated: June 10, 2015.

Kenneth J. Kopocis,

Deputy Assistant Administrator, Office of Water.

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[FR Doc. 2015-14936 Filed 6-16-15; 8:45 am]