Bloomin’ Toxins: What Public Officials Need to Know About Cyanotoxins

US Council of Mayors

Washington, DC

April 30, 2015

acarpenter@awwa.org, 202-326-6126

Opening Thought

Cyanotoxins are a very important concern for water systems and the public nationwide. We all need to:- Learn more about cyanotoxins- Develop strategies to prevent, control, and treat

cyanobacteria blooms before they become problematic- Identify treatment, communications/notification, and

response strategies for blooms that cannot be controlled

- Determine whether regulation is needed, to what level, and what nature of the regulation would be

Summary1. What are

cyanotoxins?

2. How are cyanotoxins detected?

3. What thresholds exist now?

4. Can they be treated?

5. What unresolved issues exist?

Free Manager’s Guide

The background information in this presentation comes from AWWA / WRF’s Cyanotoxins Manager’s Guide, available for free at www.awwa.org

What are Cyanotoxins?• Are byproducts of some

kinds of cyanobacteria in some circumstances.

• Separate from taste and odor issues

• Cyanobacteria are driven largely from nutrient loads, temperature, and sunlight in water bodies

Detecting Cyanotoxins

Current Advisory Levels

Example from Health Canada

“The MAC of 1.5 µg/L for microcystin-LR is believed to be protective against exposure to other microcystins (total microcystins, i.e., free plus cell bound) that may also be present. It is a conservative value, as it is derived on the basis of daily consumption of microcystin-LR over a full year.”

(Emphasis added)http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/cyanobacterial_toxins/index-eng.php

Can Cyanotoxins be Treated? (Examples – more in the guide)

Cyanobacteria Cells:• Conventional treatment (sedimentation, etc.) • Flotation

Cyanotoxins outside of cells:• Chlorination (except anatoxin-a)• Ozone• Activated Carbon (depending on carbon type)

Unresolved Issues: Monitoring

Analytical Methods1. ELISA often over-reports levels (false-positives)

2. Confirmatory tests take about 2 days to receive results, are expensive, and require advanced equipment that very few utilities have

Best Monitoring strategies3. Unclear how will be handled in UCMR4

4. More threshold criteria need to be developed for activating monitoring

Most of the threshold levels presently trace back to lifetime or year-round exposure levels (WHO, Health Canada)

Others are using mostly the same data to initiate “do not drink” and “do not use” orders for exceeding these levels in a single or a few days (Ohio, Oregon, others)

Need better analysis of the health risks posed at very low levels, especially for short times, plus the risks of of a “do not drink” or “do not use” order

Unresolved Issues: Response

Parting Thoughts: Prevention

Cyanotoxins can be addressed at the water plant, but prevention of blooms should also be a key priority

Reducing nutrients and other pollutants benefits both public health and the environment

Parting Thoughts: Regulatory Development

Let the regulatory development process work for drinking water MCLs. Simultaneously, develop rational protocols to low level detections

There are many responses other than “do not drink” and “do not use” commonly in place today for other substances:

– Increased monitoring– Increased treatment requirements– Increased optimization requirements– Triggering assessments and find/fix processes– Increasing coordination with upstream users– Public notification– Many others

Parting Thoughts: Simultaneous compliance

Some of the methods to address cyanotoxins may cause compliance problems with other rules (such as disinfection byproducts)

Need to be careful to prevent unintended consequences

American Water Works AssociationGovernment Affairs Office 1300 Eye Street, NW, Suite 701WWashington DC 20005Gen. Office: (202) 628-8303

QUESTIONS?Adam T. CarpenterRegulatory AnalystEmail: acarpenter@awwa.orgDirect: (202) 326-6126