1. Risk Communication for Emerging Contaminants
[Project #2776]
ORDER NUMBER:
91047
DATE AVAILABLE:
Winter 2004/2005
PRINCIPAL INVESTIGATORS:
Rebecca Parkin, Lisa Ragain, Martha Embrey, Catherine Peters, Gordon Butte, and Sarah Thorne
OBJECTIVES:
Emerging contaminants in drinking water entail complexities that may result in serious
consequences for utilities and the public. The overarching purpose of this project was to develop
strategies and tools that would improve risk communication about these contaminants. The
researchers accomplished this objective by (1) interpreting results from scientific and organizational
management literature and from three case studies and (2) conducting research, in collaboration
with the Des Moines Water Works (DMWW), utilizing methods from several disciplines.
BACKGROUND:
Utilities increasingly must be prepared to address complex concerns regarding new contaminants
that may pose a threat to drinking water quality and, thereby, public health. This preparedness
should focus on proactively identifying emerging concerns and evaluating their strategic importance.
Additionally, timely decisions must be made as to whether to communicate with the public what is
known about contaminant-related risks. Reliance on tactics alone (e.g., messages and methods) is
not sufficient to ensure risk communication success.
APPROACH:
The research conducted in this project relied on comprehensive literature reviews, scientifically
validated methods—specifically mental models and neural network models—as well as business
management strategies and tools. The research team used the mental model method to generate
new knowledge about emerging contaminants for the drinking water community. From the results,
they gained an understanding about how experts and customers view these contaminants. To
develop a proactive tool for identifying emerging contaminants that require a communication
response, the researchers developed a neural network model using input factors to represent aspects
of public concern. Finally, by building on existing business management methods and guidance in
risk communication literature, they designed a diagnostic tool to help utilities determine when to
communicate about emerging contaminants.
RESULTS/FINDINGS:
From the literature reviews, it is apparent that subpopulations understand drinking water issues
differently; one communication approach will not be effective for everyone who needs to be reached,
nor will it be effective over time. In the first part of the mental models research, experts shared their
knowledge in a workshop format; this resulted in the individual experts having more comprehensive
knowledge and views of risk communication and emerging contaminant issues in DMWW’s context.
In mental models interviews, the researchers found that customers did not accurately understand
the concept of emerging contaminants. Many rapidly linked it to “emergency.” To aid utilities in
making decisions about risk communication for emerging contaminants, the researchers designed
and demonstrated a user-friendly classification model based on utility-specific information and
knowledge from the scientific risk perception literature. They found that, for DMWW, frequency of

2. news media mention of a contaminant, and linkage to a population of vulnerable people (e.g.,
children, pregnant women, etc.) were the two most important attributes that predicted whether
DMWW communicated about risk. Using elements from business management strategies and tools,
the research team designed a diagnostic guide to aid utilities in assessing the need to communicate
about specific emerging contaminant risks.
IMPACT:
Industry-wide
To build customers’ positive judgments of the industry as a whole, commitment to proactive risk
communication as a core value should be stated in the industry’s code of practice and translated into
actions (e.g., comprehensive training). Further understanding of the public’s rapid linkage of
“emerging” with “emergency” may result in the need for new strategies when addressing future
contamination issues.
Company Level
Senior management support for plant-level communication activities is essential to align risk
communication strategies with the public’s expectations and trust in familiar, local spokespeople.
PARTICIPANTS:
Des Moines (Iowa) Water Works