Boil water notices as health-risk communication: risk perceptions, efficacy, and compliance during winter storm Uri

Winter Storm Uri was a disaster that impacted much of the United States during February of 2021. During and after the storm, Texas and Oklahoma experienced massive power grid failures. This led to cascading impacts, including water system disruptions and many boil water notices (BWNs). The breakdown of some communication channels and the inability to enact protective actions due to power outages, as well as travel limitations on public roads, complicated the dissemination and implementation of notifications. This research examined individuals' perceptions of risk, water quality, and BWNs during Uri. Additionally, this study sought to understand if previous experience with a BWN influenced compliance during Uri and how perceived efficacy impacted these variables. Surveying 893 Texans and Oklahomans revealed that most Uri-affected respondents believed the risks associated with BWNs were severe. Income and race were two factors that influenced BWN compliance. Age, gender, and level of education did not influence compliance. Previous experience with BWNs did not increase risk perceptions. Higher levels of perceived efficacy correlated to higher levels of compliance, perceptions of risk, and water quality, much of which support propositions of the Extended Parallel Process Model. Results suggest that pre-disaster planning and communication are imperative to helping reduce risk(s) and enhancing efficacy during a disaster, especially for novel disasters that have cascading risks, like Winter Storm Uri.

Boil Water Advisories as Risk Communication: Consistency between CDC Guidelines and Local News Media Articles

The Safe Drinking Water Act Public Notification Rule requires that customers of public water systems (PWS) be informed of problems that may pose a risk to public health. Boil water advisories (BWA) are a form of communication intended to mitigate potential health risks. The Centers for Disease Control and Prevention (CDC) developed guidance for BWAs. We examined how local US news media incorporate the CDC's guidelines when reporting on BWAs. A content analysis of 1040 local news media articles shows these reports did not consistently incorporate CDC guidelines. Overall, 89% of the articles communicated enough information for readers to determine if they were included in the impacted area. Articles that included at least some of the CDC's instructions for boiling water were likely (p < .001) to include other risk information, such as the functions for which water should be boiled (e.g., drinking, brushing teeth) and that bottled water could be used as an alternative source. However, this information was included in only 47% of the articles evaluated. Results suggest public notifications often do not serve the public need for clear risk communication.

Detecting community response to water quality violations using bottled water sales

Drinking-water contaminants pose a risk to public health. When confronted with elevated levels of contaminants, individuals can take actions to reduce exposure. Yet, few studies address averting behavior due to impaired water, particularly in high-income countries. This is a problem of national interest, given that 9 million to 45 million people have been affected by water quality violations in each of the past 34 years. No national analysis has focused on the extent to which communities reduce exposure to contaminated drinking water. Here, we present an assessment that sheds light on how communities across the United States respond to violations of the Safe Drinking Water Act, using consumer purchases of bottled water. This study provides insight into how averting behavior differs across violation types and community demographics. We estimate the change in sales due to water quality violations, using a panel dataset of weekly sales and violation records in 2,151 counties from 2006 to 2015. Critical findings show that violations which pose an immediate health risk are associated with a 14% increase in bottled water sales. Generally, greater averting action is taken against contaminants that might pose a greater perceived health risk and that require more immediate public notification. Rural, low-income communities do not take significant averting action for elevated levels of nitrate, yet experience a higher prevalence of nitrate violations. Findings can inform improvements in public notification and targeting of technical assistance from state regulators and public health agencies in order to reduce community exposure to contaminants.

A meta-analysis of public compliance to boil water advisories

Water utilities that generally provide continuous and reliable service to their customers may sometimes issue an advisory notification when service is interrupted or water quality is compromised. When the contamination is biological, utilities or the local public health agencies issue a 'boil water advisory' (BWA). The public health effectiveness of a BWA depends strongly on an implicit public understanding and compliance. In this study, a meta-analysis of 11 articles that investigated public compliance to BWA notifications was conducted. Awareness of BWA was moderately high, except in situations involving extreme weather. Reported rates of compliance were generally high, but when rate of awareness and non-compliant behavior such as brushing teeth were factored in, the median effective compliance rate was found to be around 68 percent. This does not include situations where people forgot to boil water for some part of the duration, or ingested contaminated water after the BWA was issued but before they became aware of the notification. The two-thirds compliance rate is thus an over-estimate. Results further suggest that timeliness of receipt, content of the advisory, and number of sources reporting the advisory have a significant impact on public response and compliance. This analysis points to improvements in the phrasing and content of BWA notices that could result in greater compliance, and recommends the use of a standard protocol to limit recall bias and capture the public response accurately.

Exposure Path Perceptions and Protective Actions in Biological Water Contamination Emergencies

This study extends the Protective Action Decision Model, developed to address disaster warning responses in the context of natural hazards, to "boil water" advisories. The study examined 110 Boston residents' and 203 Texas students' expectations of getting sick through different exposure paths for contact with contaminated water. In addition, the study assessed respondents' actual implementation (for residents) or behavioral expectations (for students) of three different protective actions - bottled water, boiled water, and personally chlorinated water - as well as their demographic characteristics and previous experience with water contamination. The results indicate that people distinguish among the exposure paths, but the differences are small (one-third to one-half of the response scale). Nonetheless, the perceived risk from the exposure paths helps to explain why people are expected to consume (or actually consumed) bottled water rather than boiled or personally chlorinated water. Overall, these results indicate that local authorities should take care to communicate the relative risks of different exposure paths and should expect that people will respond to a boil water order primarily by consuming bottled water. Thus, they should make special efforts to increase supplies of bottled water in their communities during water contamination emergencies.

Understanding the economic impacts of disruptions in water service

Over the past decade, there has been much attention focused on community readiness for catastrophic emergency events, such as major natural disasters or terrorist attacks. However, though the economic costs associated with experiencing such an event are high, the probability of such events occurring is quite low. At the same time, less catastrophic events that temporarily disrupt essential services to local areas, such as water and electricity, are quite common. However, there is little research that documents residents' actual economic costs when their water service is disrupted. In this paper, we contribute to the growing literature assigning economic value to residential water service by documenting the economic costs residents report from routine, small-scale water disruptions through focus groups and in-person interviews. We find that residential impacts ranged from over $1400 in savings (from working more hours than usual and eating out less than usual) to a cost of over $1000, with an overall average of $93.96. These costs, particularly when multiplied over a substantial population, become quite significant and demonstrate the importance of studying the economic costs of such events.

Crisis communication: an inequalities perspective on the 2010 Boston water crisis

OBJECTIVE

Although the field of crisis risk communication has generated substantial research, the interaction between social determinants, communication processes, and behavioral compliance has been less well studied. With the goal of better understanding these interactions, this report examines how social determinants influenced communications and behavioral compliance during the 2010 Boston, Massachusetts, water crisis.

METHODS

An online survey was conducted to assess Boston residents' knowledge, beliefs, attitudes, mass and interpersonal communication, and preventive behaviors on emergency preparedness topics dealing with the water crisis. Of a total sample of 726 respondents, approximately one-third (n = 267) reported having been affected by the water crisis. Only data from affected participants were analyzed.

RESULTS

Following an order to boil water, 87.5% of respondents refrained from drinking unboiled tap water. These behaviors and other cognitive and attitudinal factors, however, were not uniform across population subgroups. All communication and behavioral compliance variables varied across sociodemographic factors.

CONCLUSIONS

Crisis communication, in conjunction with other public health preparedness fields, is central to reducing the negative impact of sudden hazards. Emergency scenarios such as the Boston water crisis serve as unique opportunities to understand how effectively crisis messages are conveyed to and received by different segments of the population.

Agent-based modeling to simulate contamination events and evaluate threat management strategies in water distribution systems

In the event of contamination of a water distribution system, decisions must be made to mitigate the impact of the contamination and to protect public health. Making threat management decisions while a contaminant spreads through the network is a dynamic and interactive process. Response actions taken by the utility managers and water consumption choices made by the consumers will affect the hydraulics, and thus the spread of the contaminant plume, in the network. A modeling framework that allows the simulation of a contamination event under the effects of actions taken by utility managers and consumers will be a useful tool for the analysis of alternative threat mitigation and management strategies. This article presents a multiagent modeling framework that combines agent-based, mechanistic, and dynamic methods. Agents select actions based on a set of rules that represent an individual's autonomy, goal-based desires, and reaction to the environment and the actions of other agents. Consumer behaviors including ingestion, mobility, reduction of water demands, and word-of-mouth communication are simulated. Management strategies are evaluated, including opening hydrants to flush the contaminant and broadcasts. As actions taken by consumer agents and utility operators affect demands and flows in the system, the mechanistic model is updated. Management strategies are evaluated based on the exposure of the population to the contaminant. The framework is designed to consider the typical issues involved in water distribution threat management and provides valuable analysis of threat containment strategies for water distribution system contamination events.