How do our implicit biases affect our ability to protect public health?

Resources: Project Implicit is a free and anonymous test developed at Harvard University that helps individuals identify their own biases. Please click here to take the test.

As members of the drinking water sector, we hold an important role in protecting the health of our communities. In order to fully perform our jobs, it is crucial for us to understand the implications of equity, diversity, and inclusion (EDI) on our work. This article will review implicit bias, its potential effects on our ability to protect public health, and tools to evaluate our own biases. 

What is implicit bias? 

The Colorado Cross-Disability Coalition’s Glossary of Equity and Inclusion Terms describes implicit bias as an “attitude or stereotypes that affect our understanding, actions, and decisions. People are usually unaware of their own biases because they operate at the subconscious level.” Our implicit biases can affect the way we treat people, the way we perform our jobs, and the way we engage with the world.  

How does implicit bias affect our ability to protect public health?

Our implicit biases can lead us to think and act with a deficit mindset where we believe that “an individual’s deficiencies are solely determined by their cultural background and/or their own actions and behavior. When we are in this mindset, we can fail to recognize how the norms of a dominant group place barriers to success for oppressed groups because of their varied life experiences. Deficit mindset is often used in the context of the education system to describe when academic deficiencies in students of color are blamed on the students themselves or their communities rather than structural inequities.” (Adapted from Dismantling Deficit Thinking by Chelsea Heinbach, Brittany Paloma Fielder, Rosan Mitola and Emily Pattni). 

How does deficit mindset play out in the work we do in the water sector?

It could look like regulators unfairly blaming underserved communities for their non-compliance on lack of attention or ignorance. These judgements omit the overarching structural barriers to success. Deficit mindset could also look like a drinking water operator or administrator failing to post a public notice or distribute important information about their water because they do not trust their customers to read or understand the documents. No matter the context, a deficit mindset does not take into account the full picture of societal and structural inequities. These assumptions of a personal or cultural flaw lead us to ignore deeper roots of issues and could potentially affect the way we treat people that are different from ourselves and result in a failure to protect the public health of those individuals and communities. 

How are communities’ access to safe drinking water affected by inequity and implicit bias?

As members of the drinking water sector, we have a certain amount of power. Power in this case is defined as “our ability, as individuals and as communities, to produce an intended effect. Power manifests itself in both positive and negative ways and shows up formally and informally.” Our intended effect is to protect the public health of all Coloradoans by providing safe drinking water. We hold specific roles in our industry that give us the ability to produce this intended effect: operators, scientists, administrators, regulators, teachers, decision makers, board members, managers, and enforcers. If we allow our implicit biases to go unchecked, they begin to affect the way in which we are meeting our common goal of protecting public health by providing safe drinking water. This can have the negative effect of prioritizing the health of some groups of people over others. 

Two reports released in 2019 give us some insight into the effects of the systematic and individual manifestations of our implicit biases: 

1. Closing the Water Gap in the United States was published in November 2019 and co-authored by Dig Deep and U.S. Water alliance. Here are some of the key findings: 

• Race is still the strongest determinant of access to safe drinking water. 
• More than 2 million people in the U.S and Puerto Rico do not have access to water and basic indoor plumbing. 
• Latino and African American households are twice as likely as white households to lack indoor plumbing. Native Americans are 19 times more likely to lack indoor plumbing. 
• To move these 2 million people out of the water gap will require: 
• Partnership between water providers, governments, communities, and community organizations
• Flexible funding methods to fund infrastructure projects

2. Watered Down Justice was published in September of 2019 and co-authored by the Natural Resources Defense Council (NRDC), Coming Clean, and the Environmental Justice Health Alliance (EJHA). Here are some of the key findings from the report: 

• NRDC, EJHA, and Coming Clean conducted an analysis of the approximately 50,000 active community water systems in the country and sociodemographic factors such as race and income. 
• The data from June 1, 2016, to May 31, 2019, included nearly 200,000 violations of the Safe Drinking Water Act, the federal law. 
• Drinking water systems that constantly violated the law for years were 40 percent more likely to occur in places with higher percentages of residents who were people of color.
• All levels of government have failed to invest and enact policies to protect underserved populations. This segregation and discrimination has led to aging, underdeveloped, and underfunded water infrastructure in water systems serving populations of color and low-income communities.
• Nearly 130 million people in the U.S. got their drinking water from systems that violated federal law during the time period reviewed in this report.
• Small systems (those that serve less than 3,300 people) were responsible for more than 80% of all violations. The EPA has noted many small systems are “likely to serve low-income, vulnerable populations.”
• Dysfunction of the drinking water law leaves millions nationwide potentially exposed to unsafe water, whether it’s because some dangerous contaminants are not regulated or because some systems simply do not report any data at all.

Below is a statement from the CDPHE Office of Health Equity:

“The Colorado Department of Public Health and Environment acknowledges that long-standing systemic racism, including economic and environmental injustice, has created conditions that negatively affect marginalized communities, particularly people of color. These conditions, which limit opportunities for optimal health and influence individual behaviors, are critical predictors of health outcomes. To realize a future where all Coloradans can thrive, we must be leaders in undoing policies and practices that have contributed to these inequities”.

What can we do to keep our implicit biases from affecting our ability to protect the public health of all Coloradans?

The first step of keeping our implicit biases from affecting our work is to identify our own personal biases. This is a process of soul searching and looking objectively at our own behaviors. By removing judgment of ourselves we can see our actions, attitudes, and behaviors more clearly. This allows us to understand how our biases take root in our lives. A great tool to start the process of identifying personal biases is Project Implicit. Project Implicit is a free and anonymous test developed at Harvard University that helps individuals identify their own biases. Please click here to take the test. Additionally, working to better understand issues of equity, diversity, and inclusion can help us understand why this work is so important and how we can manifest the principles in our personal and professional lives.

 ➽ Kyra Gregory Drinking Water Training Specialist

Lessons learned from Boil Advisories: Public notice to thousands - Special steps for large scale advisories

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:

1. Total coliform perfect storm - incidents that could lead to a boil advisory - April 6, 2022
2. Public notice to thousands - Special steps for large scale advisories - April 20, 2022 (today)
3. What language do your customers communicate in? - Accomplishing public notification considering your community (coming soon)
4. 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

Lead testing in Schools and Child Care Facilities Drinking Water Program

Applications Now Available

Applications and program updates will be available on our lead in schools website.

Questions? Please email us at cdphe_wqcd_lead_grant@state.co.us

In January of this year (2022) the Water Quality Control Division (Division) launched the lead testing in schools and child care facilities drinking water program. This is an EPA-funded program administered by the Division and is an important opportunity to take action now and target lead testing for our most vulnerable populations. Infants and young children are most at risk, but many schools and child care facilities have not been tested for lead in their drinking water. While this is a voluntary program, we encourage public health officials to apply now and take advantage of this opportunity to partner with the Division and enhance community, parent, and teacher trust in their drinking water. 

We will be accepting applications from local public health agencies, or other county agencies to participate in the program. The ideal funding strategy is to work with our local public health and county partners to implement this program. However, if local public health and county agencies are unable to implement the program in their jurisdiction, the Division may fund public water systems to assist in these community efforts.

The program involves a holistic approach per the EPA’s 3Ts guidance beginning with outreach and education in the first phase that leads into sampling, testing, and taking action in the second phase. We will provide grant recipients outreach materials, including school and child care facility information, in addition to training and detailed instructions for developing sampling plans at each participating facility. This funding currently does not cover remediation efforts; however, low-cost immediate action is possible if elevated lead levels are found as described in our sampling guidance. These actions include shutting off the source, fixture replacement, cleaning the faucet aerator/ screen, routine monitoring, and performing common practices to reduce lead levels in drinking water:

Common Practices to Reduce Lead in Drinking Water:

• Let your water run before drinking.
• If it has not been used for several hours, run the cold water tap until the temperature is noticeably colder. Sometimes it can take two minutes or longer. This flushes lead-containing water from the pipes.
• Always use cold water for drinking and cooking.
• Never cook or drink water with water from the hot water tap. Hot water can be more corrosive and lead from plumbing can get into the water. Boiling does not remove lead from the water.
• Periodically remove and clean the faucet’s strainer/aerator.
• While removed, run water to remove debris.
• Consider using a water filter certified to remove lead and know when it’s time to replace.
• Verify the claims of manufacturers by checking to make sure that filters are listed as NSF International standard 42 and 53. Look for certified drinking water treatment units by searching for lead in drinking water at www.nsf.org.

Community public water systems are encouraged to engage with their local public health agency and local government to raise awareness of this grant and lead testing program. This is a great opportunity for community public water systems to proactively identify the schools and child care facilities they serve and familiarize themselves with the sampling process and lead service line inventory that will be required per the Lead and Copper Rule Revisions.

The current program has two required phases. The first phase provides up to $5,000 to help with community outreach. The second phase provides up to $25,000 to sample for lead in drinking water at participating schools and child care facilities. The cost of laboratory testing for lead will be funded through this grant in addition to the $30,000 available to eligible applicants.

➽  Laura Leonard PhD, Lead Testing Program Coordinator

Further considerations in developing a rule to address PFAS that may include MCLs

In March 2022, an Aquatalk blog post discussed initial steps that EPA will likely be considering as it moves forward in developing a rule to address  per- and polyfluoroalkyl substances (PFAS) that may include MCLs. As we discussed, there are many variables to consider and decisions to make. But at the beginning of the process we start with health considerations, and how to best address these with the rule. Acute and chronic health risks are considered along with vulnerable populations. This determination is yet to be made for PFAS, but it could have a profound influence on the structure and requirements of a federal PFAS rule. This second of three articles will examine the factors and variables that may go into establishing a PFAS rule with MCLs. Hopefully, this will help best prepare all of us to review EPA’s draft PFAS rule when it is published and provide constructive input to them during the comment period.

A monumental decision to make in any PFAS rule will be which public water systems are subject to the rule. Most public water systems in Colorado are non-community systems, and the majority of those service transient populations. Typically, rules for chronic contaminants do not apply to transient non-community systems, but do apply to non-community systems that serve non-transient populations, like large workplaces. Transient non-community systems tend to struggle the most with compliance, and considering the cost of PFAS monitoring and treatment, complying with a PFAS rule would be an enormous challenge for these systems. Implementing the rule for these systems would also be very challenging for states. Some states have applied or at least partially applied their PFAS rules to transient non-community systems, in some cases this is based on vulnerability to PFAS contamination.

Once it is determined which systems the PFAS rule will apply to, next the monitoring framework, analytical methods, and laboratory certification requirements need to be established. States will need to establish certification programs, minimum reporting levels, and quality assurance/quality control reviews for labs conducting PFAS analysis. Monitoring for chemical contamination typically takes place at all system entry points, and sometimes compositing samples can be done. Typically, initial monitoring would take place with four quarterly samples, although some states also required confirmation testing if PFAS values above certain thresholds were found. Counting previously collected data for initial monitoring and reduced monitoring is also likely to be considered by EPA. For example, will samples collected under the Unregulated Contaminant Monitoring Rule (UCMR) that is done from 2023 to 2025 be allowed to count for initial monitoring? If PFAS are not detected during initial monitoring or only found at very low levels, will reduced monitoring be allowed after that?

EPA will also need to decide how compliance will be determined. For chronic health risk contaminants this is typically done using a running annual average, but for acute risk contaminants this is often done as the average of one result with a confirmation sample. What are the immediate next steps if the MCLs are exceeded? For chronic constituents, Tier 2 public notice needs to be provided no later than 30 days after the exceedance, and water systems must take steps to come into compliance. If this involves installing treatment, projects of this nature can take multiple years to implement. For acute contaminants, Tier 1 public notice is required within 24 hours, and usually comes with advice to consume an alternate source of water. This situation is quite disruptive to schools, restaurants and businesses, and the entire community, particularly for individuals that need to rely on others for water delivery. 

If a public water system cannot regain compliance with the PFAS MCLs by shutting off wells or blending with other sources, then they would likely need to install treatment. At present, the most likely treatment technologies to be deployed in Colorado would be granular activated carbon or ion exchange resins. There are advantages and disadvantages to each technology, but they involve added costs, likely changes to operator certification requirements and treatment residual handling and disposal concerns and costs. These must all be taken into consideration as EPA considers what Best Available Technologies (BAT) are for PFAS. EPA will also need to examine health benefits and overall costs in their draft PFAS rule.

In our next blog, we will discuss additional considerations involved with regulating PFAS and the possibility that EPA will regulate PFAS as a group, similar to how disinfection by-products are regulated, and require treatment techniques to remove PFAS, similar to the approach for cryptosporidium. 

Thank you for being dedicated to providing safe drinking water for all!

➽ Ron Falco, P.E. Safe Drinking Water Program Manager

Marshall Fire Response

Marshall Fire - December 30, 2021

On December 30, 2021, the most destructive wildfire* in recent Colorado history occurred. The Marshall Fire, a large grass fire east of Superior, Colorado, broke out in the mid-morning hours of December 30th.  Record winds at up to 100 mph and a very dry fall contributed to the conditions that allowed the fire to spread very quickly eastward toward the cities of Louisville and Superior. Figure 1 shows a very high level overview of the approximate fire starting location and the areas that were impacted in Superior and Louisville. Boulder County has maintained an incident website that summarized the total structures destroyed and the overall eventual perimeter of the fire.  Figure 2 shows a high level view of the fire’s extent and structures burned.

* Most Destructive in terms of property damage, not acres destroyed/burned.

An excerpt of the Boulder County Website Summarizes the damage as follows:

Residential Structures:

• City of Louisville: 550 structures destroyed, 43 structures damaged; actual value** of residential damage is approximately $229,199,184
• Town of Superior: 378 structures destroyed, 58 structures damaged; actual value of residential damage is approximately $152,757,462
• Unincorporated Boulder County: 156 structures destroyed, 48 damaged; actual value of residential damage is approximately $131,255,944
• Updated totals confirmed to date countywide are 1084 residential structures destroyed and 149 residential structures damaged. Total countywide actual value** of residential damage is estimated to be $513,212,589.

(**Boulder County Assessor is the source used to report actual value.)

Commercial Structures:

• City of Louisville: 4 structures destroyed, 14 structures damaged
• Town of Superior: 3 structures destroyed, 14 structures damaged
• Unincorporated Boulder County: 2 structures damaged

 Figure 1 - Overview of the area impacted  

 

Figure 2 - Boulder County summary of the structures damaged/destroyed

As the fires burned during the afternoon of December 30th, evacuations began occurring throughout the unincorporated area of Boulder County and the cities of Superior and Louisville.  Very quickly thereafter, structures began to burn in the two cities. Superior had large scale fires happening through the night of December 30th into the morning of December 31st. As the fire was raging, Town staff were shutting off curb stops at each burned property in an attempt to keep water available for fire fighting activities. However, with the speed of the fire, many fire-fighting locations were quickly evacuated and certain hydrants kept draining the system. As the fire continued, the city began losing pressure, and a boil advisory was issued for the entire city of Superior, affecting approximately 17,000 people.

During the same time, the city of Louisville also was battling to maintain water pressure throughout their high pressure zone due to multiple neighborhoods being destroyed. As the fire progressed, the city was under the threat of running out of water because of the number of hydrants running. Also, large scale power-outages were occurring to avoid further dangers as power poles were destroyed. Therefore, Louisville made the decision to allow water to gravity feed their system from their eastern-most water treatment plant, without any chemical treatment (coagulant or chlorine). With untreated raw surface water entering the system, the CDPHE issued a boil advisory for the entire City, affecting approximately 20,000 people.

Additionally in unincorporated Boulder County, the East Boulder County Water District was issued a boil advisory due to pressure loss and fire damage. Power outages also caused advisories that were not due directly to fire damage at several small water systems. It is important to remember that in these cases, the water districts could not have done anything differently to avoid these boil advisories. In fact, the water staff were heroically working to keep water flowing to help fight the ongoing fires while some of them had even lost their own homes. 

As the fires were extinguished and the mandatory evacuation orders were lifted, the public was anxious to get back into the area to begin the recovery process. It is important to note that each city individually did an excellent job on informing the public of the boil advisories. Boulder County was also instrumental in assisting with public communication and the media. 

During the first week of January, the public water systems worked very quickly and thoroughly to fully disinfect and flush their distribution system. There were over 150 miles of distribution pipes to flush. The water systems worked in close coordination with each other and with CDPHE to execute this flushing and disinfection. The advisories were lifted on January 6, 2022. The professionalism and dedication of the water operations staff at these utilities was excellent and commendable during this challenging event. The community and state owe a debt of gratitude to the utilities as they worked through the Marshall Fire event. Governor Polis expressed his deep appreciation for all the utilities did during this very challenging time.

Figure 3: Example of a destroyed neighborhood

Figure 4: Example of a partially destroyed 

After the immediate warning of the water being unsafe to drink was addressed, additional issues arose in the weeks following the fire. There were concerns about possible contamination from burned buildings, concerns about tastes and odors in parts of the water systems, and ongoing tracking of cross connections that was necessary.  Water utility staff were proactive in sharing information with their decision makers and the CDPHE, and the public was kept in the loop via the city websites as well as public meetings. 

In the coming weeks, we will publish additional information about the large-scale boil advisories and additional issues that have arisen as a result of the Marshall Fires and other events of 2021. These topics will include:

• How do you effectively warn thousands of people about a boil advisory?
• What if a portion of your community does not speak English? 
• Fires that burn primarily structures (as opposed to forests) may release VOCs!!  
• Cross connection tracking post-fire to avoid backflow events.

 ➽ Tyson Ingels, P.E Lead Drinking Water Engineer

Lessons Learned for Boil Advisories: Total Coliform Perfect Storm

What events lead up to a boil water advisory and how to avoid them.

About 1 year ago - Ron Falco, the Safe Drinking Water Program Manager, published an article on the relentless culture of health and boil advisories (March 31, 2021 article). In that article he discusses how boil advisories still occur at about the same rate even though the number of E.coli events has dramatically decreased between the year 2000 and now.  

Figure 1: 25,000 people were effected by the Englewood e.coli boil advisory event (photo courtesy of “The Denver Channel”)

Since the time of the publishing of that article in March, 2021 - Colorado has seen the largest boil water advisories in recent years occur for a variety of reasons. In the next series of four short articles, we will explore several topics around boil advisories and some lessons learned in 2021 that are worth exploring. As always - the department staff are here to help water providers avoid the events that result in boil advisories as well as assist you when disaster strikes and boil advisories become necessary. The topics we will explore are as follows:

1. Total coliform perfect storm - incidents that could lead to a boil advisory and how to avoid them
2. Public notice to thousands - Special steps for large scale advisories
3. What language do your customers communicate in? - Accomplishing public notification considering your community
4. Do you really want to sample a home for compliance?  - Total coliform special sample stations

Today - we will discuss the total coliform rule and how it can lead to boil water advisories. There are specific incidents to watch out for in total coliform sampling. Total coliform sampling frequency is determined by your population. While most Colorado public water systems are very small - a few systems must collect dozens or even hundreds of total coliform samples each month (see Figure 2 below). You can find your required samples in your monitoring schedule.

Figure 2: Table 11.16 from Regulation 11 (Colorado Primary Drinking Water Regulations - 5 CCR 1002-11) specifies total coliform frequency.

When a large number of samples are being collected, many things can go wrong.  What many water professionals may not realize is that even if only 1 of those samples comes back positive for E.coli, then a boil advisory for the whole system could be required. 

Once E.coli has been detected, if any repeat samples come back with total coliform or E.coli present, then a mandatory Tier 1 public notice is required. The difficulty of understanding the extent of the boil advisory during an E.coli positive event is that the samples take 18 to 24 hours to incubate. Once a positive sample and its repeat samples have been taken, up to 72 hours could have passed since the original sampling event. 

With most water systems, it is difficult to determine the full extent of where water could circulate within 72 hours. Therefore, if a positive E.coli is detected and confirmed, the initial assumption is that the contamination may be throughout the system. Many times systems ask the question, but the contamination was only detected at one site - so why would the notice be system wide?

It is also important to remember that each total coliform sample location is a sentinel site representing your distribution system water quality. Each site does not only represent a specific location, but rather a substantial portion of the distribution system. Therefore, if there is contamination in that representative sample, contamination is presumed to be present in part or all of the distribution system pipes. 

The ramification of not quickly warning the public about confirmed E.coli contamination is that a large number of people could get sick from the water because potentially impacted populations were not warned the water is unsafe to drink.

A few of the lessons learned and possible ways to avoid or minimize the impact of a boil advisory follow. However, it is important to remember that these events could happen to any public water system. 

• When you take total coliform samples - it is critical that proper sampling procedures are followed.  If a total coliform positive or E.coli positive occurs, follow proper sampling procedures. Inspect the site and determine if contamination exists. Ensure that sampling faucets are thoroughly disinfected before sampling and that the water is allowed to run for sufficient time to collect distribution system water. 
• If the sample comes back E.coli positive - do not assume there was sampling error, or that somehow you received a ‘bad batch’ of sample vials, but rather act in a manner that the water actually contained those bacteria when you sampled and mitigate that risk. 
• Focus on your distribution system and understand the fate of the drinking water - the ability to understand the hydraulics of where water can travel over time can change the fate of a boil advisory from affecting a specific area to affecting the whole system.  Each water supplier must maintain redundancy in their system, balance water age, and also consider simultaneous compliance. 
• Run desktop activities - do not wait for the event to occur to rehearse what the responses will be. Rather, perform ‘what if’ scenarios with staff to understand if an E.coli positive occurred in a certain area - what would be the extent of the advisory? Similar activities can be performed simulating pressure loss events.

As always, reach out to the department for guidance and partnership during challenging events. We stand ready to assist you when issues arise.

➽ Tyson Ingels, P.E Lead Drinking Water Engineer