In the Aqua Talk post on April 6 about the total coliform rule and potential for boil advisories, we discussed that we will publish three additional articles about these large-scale boil advisories and the specific challenges and lessons learned. As a reminder, the four part series is covering the following topics:
- Total coliform perfect storm - incidents that could lead to a boil advisory - April 6, 2022
- Public notice to thousands - Special steps for large scale advisories - April 20, 2022 (today)
- What language do your customers communicate in? - Accomplishing public notification considering your community (coming soon)
- Do you really want to sample a home for compliance? - Total coliform special sample stations (coming soon)
Both the Englewood boil advisory event in August, 2021 and the Marshall Fire that started on December 30, 2021 led to boil advisories affecting more than 25,000 people. To read more about the Marshall Fire boil advisories, see our April 13, 2022 article. Figures 1 and 2 show the extent of the areas impacted by the boil advisories.
Figure 1: 25,000 people were affected by the Englewood E.coli boil advisory event (photo courtesy of “The Denver Channel”)
Figure 2 - Boulder County summary of the structures damaged/destroyed
Regulation 11, Section 33 contains the Public Notification Rule. Essentially, that specific rule prescribes when and how the public needs to be notified about the quality of their drinking water. There are different tiers, or severities, of public notice depending upon the urgency of the information. The entire construct of the public notification rule originates in the 1996 Amendments to the Safe Drinking Water Act by the U.S. Congress. At that time, Congress intended for the public to have a ‘right to know’ about the quality of their water supply. Therefore, when a situation arises that could potentially result in waterborne disease if the water is consumed, the public needs to be informed as quickly as possible that they should avoid drinking the water. The Colorado Department of Public Health and Environment (the department) has expanded upon the public notification rule and developed the ‘acute policy’ to help define when we will require Tier 1 boil or bottled water advisories. Tier 1 public notice is the most urgent public notice and must be completed within 24 hours.
Ensuring that the public knows the water is unsafe to drink is a challenging task. Figure 3 contains an excerpt from Regulation 11 about the appropriate methods for delivering a Tier 1 public notice. The key term to understand in the regulation is ‘direct delivery’. In general, that means that each customer must receive a physical piece of paper at their property warning them not to drink the water.
Figure 3: Excerpt from Regulation 11.33 - Public Notice Rule.
When a boil advisory affects 100 homes, it is relatively straightforward to hand-deliver 100 notices to those homes warning the public not to drink the water. However, when a boil advisory affects many thousands of people, it is literally impossible to accomplish hand-delivery of public notice within 24 hours. There are more efficient and effective ways to accomplish notifying the public when the scale is too large to do hand delivery.
While the regulation specifies broadcast media and reverse 911 as options, it is important to note that both of those methods are severely limited.
Reverse 911: Many homes do not have a home phone and therefore would not receive a reverse 911 call. Reverse 911 systems will reach many people, but will not be sufficient alone. They also struggle with substantial delays and may give the notice hours after others have received it.
Broadcast media: Many folks do not watch local broadcast media and may not receive the notice that way. While broadcast media can be used, it should not be considered adequate to reach all or even most customers.
Each of the large boil advisory scenarios involves cooperation between the department and the public water system on which activities constitute adequate distribution of public notice. The department works very closely with each entity during one of these events to fully understand the population that needs to be reached and to proactively brainstorm the most effective and practical methods of warning the public. In the recent events of 2021, broadcast media and reverse 911 were used. Also, additional methods that are more modern were used to reach the public at large including:
- Social media - the use of sites like facebook, twitter, and nextdoor to adequately get the word out that the water is unsafe to drink can reach a large number of people very quickly. However, it is important to remember that there are specific populations that do not engage in social media.
- Local county communications - Tri County Health Department and Boulder County Public Health were key partners in helping to warn and assist local hospitals, restaurants and businesses during the boil advisories.
- Road signs - if the public works or county has access to temporary or even permanent road information signs, posting that the water is unsafe to drink with a phone number or website for more information is an effective way to help spread the message as people enter your service area.
- IPAWS - Cellphone broadcast - during the Englewood boil advisory - a broadcast message was sent out to warn users not to drink the water. While there was a mistake, and the broadcast went to nearly 300,000 people instead of the intended audience, the cell-phone broadcast was very efficient and was able to notify many thousands of people instantly that there was a problem with the drinking water. This system is typically administered by the county Office of Emergency management (OEM) and therefore requires coordination to implement. The department recommends considering this option as part of the public notice to large numbers of people. Figure 4 below shows the map of IPAWS coverage in Colorado. There are also emergency notification networks by county (e.g., CodeRED for Jefferson County).
- Regardless of all the methods chosen - the importance of multiple methods cannot be overstated. To reach thousands of people quickly with a message, it will require an integrated, strategic approach. Participation in workshops and planning activities is critical to successfully be able to accomplish this.
Figure 4: IPAWS coverage in Colorado
Another important item to plan for is giving the ‘all clear’ signal to the public. First, it is important to establish expectations at the beginning that the boil advisory will last a few days. Water systems must be disinfected and properly flushed, followed by confirmation sampling, before the ‘all clear’ can be given. When it comes time to communicate that the water is safe, it is important to have an equally robust strategy preferably involving the same techniques so that members of the public are not left wondering if their water is safe to drink.
As always, we strongly encourage pre-planning, desktop exercises and scenarios, and communication with us and other stakeholders well in advance of an emergency occurring. It is very challenging to determine and develop the process to accomplish this public notice in the midst of the crisis. Please don’t hesitate to reach out to us if you would like to explore these concepts further.
➽ Tyson Ingels, P.E Lead Drinking Water Engineer
