Upcoming Perchlorate Rule

Program Manager message:

Colorado’s Safe Drinking Water Program is not the only such program in the United States with a newsletter. Over the years, I have subscribed to a few of these newsletters, and sometimes we have reprinted or used articles from them with permission. In this case, I recently read an excellent article in the Arkansas Drinking Water Update newsletter regarding EPA’s proposed perchlorate rule. I reached out to my counterpart in Arkansas, Lance Jones, who authored the article and gained his permission to reprint it here. We are also adding a Colorado perspective regarding likely perchlorate rule impacts on Colorado’s public water systems. 

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

EPA Proposes Perchlorate Rule

On January 2, 2026, the Environmental Protection Agency (EPA) issued a proposed Rule under the Safe Drinking Water Act to regulate perchlorate (ClO4-) in drinking water as part of the National Primary Drinking Water Standards.

The proposed Rule includes a Maximum Contaminant Level Goal (MCLG) of 20 micrograms per liter (ug/L). EPA is also co-proposing enforceable Maximum Contaminant Levels (MCLs) of 20 ug/L, 40 ug/L, or 80 ug/L for perchlorate and will apply to community and non-transient public water systems.

Initial monitoring consists of quarterly monitoring or semi-annual for small ground water systems, for a 12-month period, with routine monitoring determined by those results. Systems with a running annual average above the MCL require quarterly monitoring, systems less than the MCL but greater than or equal to 4 ug/L require annual monitoring (surface water) or triennial (ground water) monitoring, and every 9 years for systems less than 4 ug/L. 

Perchlorate has had a back-and-forth regulatory history for the past 25+ years. Starting with including perchlorate levels in drinking water systems under the 1999 Unregulated Contaminant Monitoring Rule (UCMR). The results led to a 2011 decision by EPA to regulate perchlorate in drinking water. EPA proposed a Rule to regulate perchlorate in drinking water in 2019. In July 2020, EPA withdrew the determination to regulate perchlorate. A legal challenge of the decision to withdraw was filed and led to a 2023 court decision to vacate the withdrawal. EPA entered into a consent decree to sign and issue a final Rule to regulate perchlorate in drinking water by May 21, 2027.

Perchlorate is commonly used in solid rocket propellants, munitions, fireworks, matches, signal flares, and vehicle airbag initiators. It has also been associated with some imported fertilizers and trace amounts can result from improper handling and degradation of hypochlorite solutions.

Perchlorate can potentially interfere with the thyroid gland hormone production. Changes in thyroid hormone production in pregnant women are associated with adverse neurodevelopmental effects in their children. Thyroid hormone level changes at other life stages can lead to hyperthyroidism, developmental outcomes, and cardiovascular system impacts.

EPA’s data show that perchlorate is not widespread in drinking water systems and EPA expects less than 1,300 of the over 135,000 regulated water systems nationwide to find perchlorate levels above the proposed limits. For systems that do find elevated levels of perchlorate, treatment options include ion exchange, biological reduction, reverse osmosis, and blending with another source.

The sampling of several Arkansas water systems in 2001 and 2002 found no detects of perchlorate. ASD will add sampling of perchlorate to the current compliance monitoring efforts upon EPA promulgating a final Rule.

More information about perchlorate in drinking water can be found on the EPA website at:

https://www.epa.gov/sdwa/perchlorate-drinking-water#proposed-perchlorate

➽ Lance Jones, P.E. Health Program Administrator, Arkansas DPHP Environmental Health Engineering

Partnering for public health during Drinking Water Week

Governor Jared Polis has proclaimed next week, May 3-9, as Drinking Water Week in Colorado. The Colorado Department of Public Health and Environment will observe the week with the theme, "Clean, accessible drinking water is a pillar of community and public health."

As drinking water providers and key stakeholders, you are the foundation upon which this pillar rests. This annual celebration is an opportunity to remind Colorado residents and leaders that the ability to simply turn on a drinking water tap is a modern achievement, one that requires continued vigilance and investment.

Providing reliable, high-quality drinking water is an essential service that underpins the quality of life for every community in Colorado, and it is tied directly to the dedication of water professionals. From source water protection to advanced treatment and robust distribution, your work ensures high-quality water reaches every home and business. Take time during Drinking Water Week to celebrate your expertise and inspire greater public appreciation for drinking water.

The department created a commemorative bookmark for the observance week. The printable bookmark and other Drinking Water Week materials are available on our 2026 Drinking Water Week web page.

We encourage our partners to join in this effort. The department will post content on Facebook and Instagram throughout the week. By sharing our posts and promoting your own local successes, we can work together to ensure that every Coloradan understands the value of their water source and the crucial role you play in delivering a safe and reliable supply. For more information about Drinking Water Week, visit the American Water Works Association website.

➽ Lilie Waterman, Marketing and Communications Specialist

Arsenic Water Quality Standards

 

Right now - arsenic is regulated in wastewaters statewide due to water quality standards that were conceived of over 20 years ago. Because arsenic can be quite detrimental to human health and for surface waters that are a source of drinking water, it is important to protect the drinking water supply by adopting protective standards.

Colorado has surface water standards to protect both drinking water (water supply) and fish ingestion. The surface water standard for water supply is 20 nanograms per liter (ng/L). This is quite low, and comparable to the PFAS maximum contaminant levels proposed by EPA (4 nanograms per liter).

The Safe Drinking Water Act regulates arsenic at 10 micrograms per liter (ug/L), or 10,000 nanograms per liter as a maximum contaminant level (or MCL). Also, the practical quantitation limit, or PQL for arsenic currently stands at about 1 micrograms per liter. Having such large discrepancies between the water quality standard, the drinking water MCL, and the PQL creates challenges in implementation of standards within the permitting framework.

The division worked with stakeholders and the commission throughout the 2010s and the early part of this decade to implement statewide temporary modifications because of uncertainty in what the standard should be, and the challenges presented by these discrepancies. While being an interim solution that is unique to Colorado, this solution is only temporary. Each time we extend it, we have to get it approved by our partners at EPA Region 8. Colorado has utilized the temporary modification tool since 2011 (Reg. No. 38.79) to recognize the underlying, use-based standard as a goal while using the level generally deemed to be technologically feasible to set permit limits (i.e., 0.02-3 ug/L). Currently, the arsenic temporary modification is scheduled to expire in 2029. 

As part of the Water Quality Roadmap, the division is currently scoping out what implementation of the protective arsenic standards will look like in the permitting framework. Keep informed of our progress through our quarterly roadmap meetings, which will also offer regular stakeholder input opportunities. The next Roadmap meeting will be held on March 5, 2026.

➽ Tyson Ingels, Watershed & Engineering Program Manager

EPA PFAS Rule Update: What Colorado Water Systems Need to Know

The division is closely monitoring recent developments from the EPA regarding its 2024 drinking water PFAS Rule. While the EPA has signaled potential changes to the regulation, the official rulemaking timeline remains unchanged, with Colorado’s adoption scheduled for August 11, 2025. The division is committed to maintaining clarity for water systems and intends to highlight this federal uncertainty in its Statement of Basis and Purpose that is part of the rulemaking. The division is committed to communicating with water systems when federal action occurs and proposing revisions to Colorado’s PFAS rule to align with federal requirements before the Water Quality Control Commission.

Resources: 

• CDPHE - Regulating per- and polyfluoroalkyl substances (PFAS) in drinking water
• CDPHE - PFAS mapping (includes PFAS in treated drinking water map and data) 
• CDPHE - PFAS Grant program

EPA’s Announced Changes

In May 2025, the EPA announced that it may significantly revise the 2024 PFAS Rule. Proposed changes include:

• Removing and reconsidering regulations for four PFAS compounds: PFNA, PFHxS, HFPO-DA (GenX), and PFBS.
• Retaining Maximum Contaminant Levels (MCLs) and monitoring requirements for PFOA and PFOS only.
• Eliminating the Hazard Index concept and its associated MCL for PFAS mixtures.
• Extending the compliance deadline for PFOA and PFOS MCLs from 2029 to 2031.

These changes are planned to occur via a revised PFAS Rule proposal in Fall 2025, and anticipated finalization in Spring 2026.

It’s important to note that, so far, EPA’s announcement has not indicated changes to the requirements for initial monitoring of six PFAS compounds by the April 2027 compliance deadline.

Colorado’s Approach

Colorado is moving forward with adopting the PFAS rule this summer to retain full Safe Drinking Water Act primacy. This ensures that the division, not EPA, will continue to oversee PFAS compliance, monitoring, and enforcement across Colorado systems.

To account for the evolving federal landscape, the division has included a “federal flexibility provision” in its rule language. This provision allows for the automatic extension or stay of any deadlines or requirements altered by the final federal PFAS Rule, minimizing disruption for water systems.

Why Primacy Matters

Colorado’s decision to adopt the rule in 2025 avoids a primacy extension agreement with EPA. Under such an agreement, EPA would have authority over PFAS compliance while the state catches up. This would fragment regulatory oversight, complicate compliance for Colorado’s water systems, and limit our decision-making authority during this period. We believe that the division can provide the best decisions for water systems and their customers in Colorado.

The division’s experience with the Lead and Copper Rule Revisions (LCRR) demonstrated the benefit of timely rule adoption. Being one of the few states to implement LCRR on schedule allowed the division to retain control and better support systems through technical and operational challenges. The same advantages apply here.

Operational Implications for Water Systems

Drinking water data across Colorado shows that PFOA and PFOS are the primary PFAS compounds detected in public water supplies in Colorado. The removal of other compounds from the federal rule should not change which systems require PFAS treatment in Colorado. However, there may be impacts to treatment plant design and operation, which the division will work to consider during rule implementation.

In the meantime, systems are encouraged to stay engaged and continue monitoring for PFAS to meet initial monitoring requirements. The division will provide ongoing updates and technical assistance throughout this evolving process.

Stay Informed

The division is committed to supporting Colorado’s water systems during this transition. As the revised federal rule develops, Colorado will adapt, but always with the goal of maintaining clarity, consistency, and strong public health protections.

➽ Haley Orahood, Regulatory Development and Implementation Specialist

PFAS Rule and CCR Revisions: Update on Stakeholder Engagement on Rulemaking

In Spring 2024, EPA finalized the Per- and Polyfluoroalkyl Substances (PFAS) Rule and Consumer Confidence Report (CCR) Rule Revisions. The PFAs Rule will protect public health by requiring ongoing monitoring of “forever chemicals” beginning in 2027 and setting health-based limits starting in 2029. The CCR Rule Revisions modernize the content and delivery methods for all community systems and increases the frequency and accessibility of water quality reports for consumers served by larger systems beginning in 2027. 

In August 2024, the division launched a stakeholder engagement process in support of a rulemaking hearing before the Water Quality Control Commission to adopt these federal rules into the Colorado Primary Drinking Water Regulations (Regulation 11). Between August 2024 and January 2025, we held a total of seven stakeholder meetings and two workgroup meetings in support of the stakeholder process. We appreciate the significant contributions from water providers, environmental organizations, and members of the public. This collaboration is essential for developing effective and sustainable regulations that address the specific needs of our state.

Through the stakeholder process, we have:

• Developed Draft Regulatory Language: The feedback received from stakeholders has directly informed the development of draft language for the upcoming PFAS Rule and CCR Rule Revisions. 
• Created PFAS Rule Resources: To aid water providers in navigating the complex requirements, we have developed a PFAS Rule page with guidance and a frequently asked questions document, an initial monitoring compliance check worksheet to help understand the timing requirements for monitoring, and are in the process of developing tools to allow submission of UCMR 5 PFAS data for use in meeting initial monitoring requirements.
• Updated CCR Content: While most content changes under the CCR Rule Revisions are not required until 2027, there are a few changes to CCRs distributed in 2025 required under the Lead and Copper Rule Revisions. The division has updated CCR draft templates for 2025 to capture the language and content required to be included in CCRs.

Looking ahead, the next major milestone is the rulemaking process before the commission. This is a crucial stage where the commission will review the draft regulations, consider public input, and ultimately make a decision on whether to adopt these rules into Regulation 11.

Important Note: There has been some recent developments at the federal level. EPA has been granted abeyances by the DC Circuit Court concerning lawsuits regarding the federal PFAS Rule. These abeyances were granted to allow the new administration time to review the rule and the plaintiff’s petition to the Court. On May 14, 2025, EPA announced that it was considering delaying compliance with the PFAS standards but no specific mention was made about the testing requirements. We are actively monitoring this situation and will provide updates as they become available. None of this impacts the CCR rule. 

We recognize that navigating these regulations can be complex. Therefore, we are committed to keeping you informed throughout the process. We will provide updates on the rulemaking process and opportunities for public comment.

How to Stay Informed:

• Visit the Division's Engagement Website and sign up for notifications
• Attend Commission Meetings: Commission meetings are open to the public, and your participation is encouraged. For more information about upcoming meetings and hearings please visit the commission's website.

We believe that everyone plays a vital role in shaping water policy. By staying engaged, we can collectively work towards ensuring clean and safe drinking water for all Coloradans.

➽ Bryan Pilson Technical, Regulatory Implementation, and Coordination Unit Manager

Program Manager message: Looking ahead after the 50th Anniversary of the Safe Drinking Water Act

In 2024 we celebrated the 50th anniversary of the Safe Drinking Water Act signed by President Ford in 1974. This landmark legislation set unified standards for water systems across the United States to protect public health. The Act set up a now time-tested framework in which EPA largely sets the rules and requirements via a defined process and with stakeholder input, and then states implement via primacy. As our work to improve public health continues, what factors and principles do we need to consider on our path through the next 25 to 50 years?

In December 2024, I had the opportunity to participate in and speak at a symposium at the University of Wisconsin on just this topic. The symposium was sponsored by the Water and Health Advisory Council, a multidisciplinary group of water professionals involved in drinking water and public health protection. The title of the symposium was: The Next 50 Years of Drinking Water in America. I participated in the “Prioritizing Risk” panel. 

Two of the risk reduction opportunities were identified as legionella and manganese. The upcoming federal revisions to the microbial and disinfection byproducts (M/DBP) rules should help us to start addressing legionella. Legionella is now a major cause of waterborne disease outbreaks, and the illness is sometimes fatal. At this point in time, it does not appear that a rule to address manganese is in the pipeline. Manganese has a health advisory, and some nervous system health risks similar to lead. However, another big risk was identified as losing the progress we have made due to aging infrastructure. Attendees were particularly concerned about distribution systems. Again, the M/DBP rules may help with some operational aspects of those, but the overall drinking water infrastructure situation is a serious concern. 

Are we approaching a time when affordability, especially for small systems, will jeopardize the ability to comply with rules for new contaminants and keep up with the fundamental infrastructure that a safe water supply relies on? Many people believe that we have already passed a tipping point in that regard and that small systems face truly daunting challenges over the next few decades.

So the question arises, how do we (as individuals, communities, states and a nation) pay for safe drinking water? It appears that all options need to be on the table. Currently, the Drinking Water State Revolving Funds that involve large infusions of federal dollars combined with the state programs that operate them and keep the money “revolving” through more and more loans is a great help, especially for small, rural communities. But this funding source is not enough. How much more funding can be gained from state and federal sources? Should we be exploring more public/private partnerships? Should drinking water be treated like education where small, rural systems are supported from the broader state population? What about individual assistance programs, like those that occur for power utility bills?

The answers to these questions are not known at present, but it’s important to ask them and work on solutions for the next decade and beyond. Look for more information about the next 50 years in drinking water in this space throughout 2025. Thank you in advance for your efforts to keep drinking water safe for the next half a century!

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

Happy 50th Anniversary to the Safe Drinking Water Act

Water is a precious resource. Water is life, and we need to continue protecting it. On December 16, 2024 we will celebrate the 50th anniversary of the Safe Drinking Water Act. President Ford  (a part-time Vail, Colorado resident) signed it in 1974. This landmark legislation set unified standards for water systems across the United States to protect public health. The act set national health-based standards to protect against naturally occurring and human-made contaminants. 

That work continues today. In April 2024, the EPA set standards for the group of chemicals known as PFAS. That made headlines. It was the first new standard to be set since 2000. However, the typical water consumer probably never sees all the routine things that happen under the act. The Water Quality Control Division (division)  works every day to assist and educate our water partners across the state to ensure that water is properly treated and tested. Since 1974, the risk of waterborne disease and children’s lead exposure from drinking water has been dramatically reduced. The Safe Drinking Water Act also gives people the right to information about tap water from their community systems. This occurs annually in Consumer Confidence Reports (CCRs), another rule EPA updated in 2024, and via the Public Notice Rule when violations occur. This transparency helps people trust that their tap water is safe.

Moreover, the Safe Drinking Water Act provides federal money to help communities improve their drinking water systems, often costing millions of dollars. That benefit comes from the Drinking Water State Revolving Fund (DWSRF). South Fork, Colorado is a prime example of how well it can work. The town of about 600 people in Rio Grande County is located on the west side of the San Luis Valley. Two years ago, the town built a new water system to replace a patchwork of private wells. Now, there is enough treated water to supply 158 houses and to fight fires if needed. Town officials have stated that they would never have been able to achieve this project without the Water Quality Control Division's guidance and the Safe Drinking Water Act. 

We’ve made tremendous strides in the last 50 years improving drinking water quality. And we’re not done. Today, the division supports innovative ways to combat current and future challenges like new and emerging contaminants, wildfires, and more. We’re assisting dozens of communities helping them to replace aging water infrastructure, and that need will only expand as we head into the future. We’re also working with communities across the state to protect people from drinking water pipes that may contain lead. Water providers are looking for them. In several communities like Denver, the removal of lead pipes is already underway. 

The Safe Drinking Water Act provides our direction. The bottom line: we want people to have the water they deserve. The division will continue to do that here in Colorado, with guidance from the Safe Drinking Water Act, for years to come. Together with our water utilities, we’ve been safeguarding drinking water for the past 50 years via the Safe Drinking Water Act. 

Thank you for all the progress over the last half a century!

➽ John Michael Marketing and Communications Specialist

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

New Rules in Challenging Times - Recycled from our October 2008 newsletter

Hello everyone, 

As discussed briefly in a recent Aqua Talk article, the 2020s promise to be a decade of substantial changes to the federal Safe Drinking Water Act. I believe that these will be the most significant and intense set of regulatory changes we have experienced since the 2000s. So, look for an upcoming article summarizing the Upcoming Regulatory Changes in the 2020s, one of which - the Lead and Copper Rule Revisions is already in process. In the meantime, we wanted to share an article that ran about 15 years ago regarding tackling new rules in challenging times. Those were challenging times - remember the Great Recession? Well, the 2020s have brought their own set of challenges as we grapple with a host of new drinking water rules: pandemic with an immediate economic crisis followed by ongoing supply chain issues, staff shortages, inflation and economic risks. We thought we would share this article from the past as a reminder that we have tackled new rules during challenging times before. We believe that by working together we can rise again to meet the needs of keeping drinking water safe. Thank you.

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

New Rules in Challenging Times - Originally published 2008

Ron Falco, P.E.

Since 2007 the Drinking Water Program has adopted the Long-Term 2 Enhanced Surface Water Treatment Rule, Stage 2 Disinfectants/Disinfection By-Products Rule, and the Groundwater Rule. These are major new rules that will apply to every public water system in the state. We are striving to help water systems meet the federal early implementation requirements of the first two rules, and I urge all public water systems to conduct the necessary monitoring and distribution system analysis so the correct approach can be used for your system. Failing to meet the early implementation requirements can have negative consequences going forward. For example, failing to monitor your surface water as required can lead to a higher bin classification than truly necessary, which may in turn lead to a requirement to install additional treatment. We are also reaching out to groundwater systems in advance of the December 2009 effective date for that rule.

In the coming year, the program will also be required to adopt the minor Lead and Copper Rule revisions to avoid seeking an extension with EPA. In response to the Alamosa outbreak, we will be working with stakeholders to update and revise our regulatory approach to disinfection waivers. A number of water systems have also asked that we update and revise Article 12 regarding cross connections. 

All of these changes will certainly keep program staff and public water systems very busy. I wish to thank all of the water systems that have helped us develop our regulatory language and implementation strategies. Please contact us if you wish to participate in any of these efforts or have some feedback that you would like to provide. We will be facing these new challenges at a time when economic uncertainty makes it especially difficult to obtain the necessary resources to complete the job at hand today, let alone the resources needed to prepare for tomorrow. We are available to help you and we will continue to sponsor training events all around the state. Through it all, I know that we will all do our best to maintain our vigilance and protect public health. Thanks.

 

Federal update - Microbial/Disinfection Byproducts (M/DBP) Rule Update (Part 1)

In 2020 EPA began stakeholder engagement as part of its review of Microbial/Disinfection Byproducts (M/DBP) Rules. The M/DBP rules are an important suite of drinking water rules designed to protect the public from the acute risks associated with waterborne disease outbreaks by requiring strong treatment and disinfection. However, the rules also try to balance the chronic health risk associated with cancer from certain disinfection byproducts. The Safe Drinking Water Program engaged in this process and shared some of our thoughts and experiences with these rule.

Regarding microbial risks, the department shared experiences in evaluating sources of drinking water that could be Groundwater Under the Direct Influence (GWUDI) of surface water and disinfection treatment evaluations. We also recommended that EPA synchronize its timing of promulgating any new or updated M/DBP rules with final regulatory determinations regarding cyanotoxins and brominated disinfection byproducts.

We shared our belief that sources of drinking water initially identified as groundwater, but that are actually under the direct influence of surface water represent a significant public health risk from waterborne disease. This is because filtration treatment to remove pathogens like giardia and cryptosporidium is not required for groundwater sources. The Safe Drinking Water Program has long recognized this risk and developed a policy to determine whether groundwater sources were being directly influenced by surface water. This policy was developed in 2012 after extensive engagement with academic researchers and stakeholders across Colorado. Unfortunately, it takes well-specific evaluations to determine whether the source is indeed GWUDI. This is an impactful determination for the water system if their source is re-classified to GWUDI. We work with water systems to both gather data in support of these determinations and after determinations are made to see if a source can be improved to be able to be reclassified to groundwater and, if not, help move along the process to install surface water treatment. Over the last ten years of implementing the policy, we have evaluated about 456 wells, and 87 of them were determined to be GWUDI. Thus, addressing this source water risk is a significant public health protection advance. We also recommend that federal requirements or guidance specifically address hand-pumped wells often seen at campgrounds.

We further shared that as part of our evaluations of surface water treatment disinfection, we launched the Disinfection Outreach and Verification Effort (DOVE) around 2016. We are evaluating filtration and disinfection at each surface water treatment system in Colorado to ensure that log removal requirements in the surface water treatment rule are met. University research showed serious issues with EPA baffle factor guidance and that it was not sufficiently protective. As part of the DOVE process, about 70 percent of Colorado’s surface water treatment systems had some type of treatment or sampling location issue to address. 

We also called to attention that distribution system problems can be a concern for all water systems, and not just surface water systems. The 2008 Salmonella outbreak at Alamosa, Colorado was at a groundwater system with deep wells and most likely caused by a storage tank deficiency. Issues with cross connections, tanks, etc. occur at all systems. Applying any proposed storage tank or cross connection rules  only to surface water systems is not justified. Instead of only promulgating new rules, we also encouraged EPA to consider guidance and how they institute primacy requirements for states as part of their routine processes. 

One topic of interest to EPA is considering requiring a numeric disinfectant residual concentration beyond a “trace” for all water systems. We shared Colorado’s experience involving studies that showed colorimetric “trace” readings were not reliable. The detection limit for chlorine was 0.09 mg/L. We also highlighted our data showing 300% fewer E. coli positive samples when chlorine residual was above 0.2 mg/L, and that we have had very few E. coli violations in Colorado since 2014. Finally, we shared our understanding of  concerns about transition for historically non-disinfecting systems and that  we think EPA should consider disinfection waivers for water systems with adequate source and other protections in place. 

We also shared our our view DBP concerns are likely to be exacerbated going forward by a variety of source water quality issues. These issues include:

• Drought
• Wildfires
• Nutrients
• DBP Precursors
• Wastewater treatment “Effluent dominated” or impacted sources

It will be the mid-2020s before EPA fully updates the M/DBP rules, but these are highly impactful rules and we encourage water systems to be aware of and engaged in the process. Thank you.

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

Culture of Health - Boil Orders

Our Culture of Health is Relentless

Hello everyone,

One of the activities that we get involved with requires responding to acute public health threats in drinking water that could lead to waterborne disease outbreaks. These events can entail E. coli violations when there is confirmed bacterial contamination in a water system to line breaks that depressurize large segments of a distribution system. When a system loses water pressure contamination can enter and make people sick when full water service is restored. Both of these situations involve issuing what we call a “Boil Water Order,” which is actually a requirement to issue Tier 1 public notice under the Colorado Primary Drinking Water Regulations (Regulation 11). The Tier 1 public notice typically advises the public to boil their water or obtain an alternate source of water, like bottled water. There are other situations including treatment failure and chemical contamination that have resulted in Tier 1 public notices. In the case of certain events, boiling the water could concentrate the contamination, and so an alternate water source is advised.

Fortunately, the number of E. coli violations has decreased significantly in recent years, so they are pretty rare now. In the 1990s, there were 114 E. coli violations at public drinking water systems in Colorado, but in the 2010s that number was reduced to 32. In fact, from 2014 through 2020 there were only 11 such violations and most of those occurred at just a few systems that had not been previously regulated. We believe that water systems and certified operators have done an excellent job improving disinfection, controlling cross connections and protecting storage tanks resulting in the decline in E. coli violations. 

However, our overall numbers of boil water orders has not steadily decreased. Of course, disasters like floods may cause increased numbers of boil water orders to be issued. But boil water orders from main breaks and other distributions system problems appear to have been increasing. It is hard to know if actual infrastructure problems are on the rise, or whether water systems are just more aware of the need to work with us through these situations and issue Tier 1 public notice. Earlier in this century we typically issued 30 to 50 boil water orders per year. That seemed to stabilize in the high teens during the four year period from 2015 to 2018, but since then ticked up to near 40 in 2019, 50 in 2020 and already about 10 in the first quarter of 2021.  

Whether it’s an E. coli violation or main break resulting in pressure loss, department staff help water systems with assessing the situation, assuring compliance with the Tier 1 public notice requirement and reviewing the disinfection, flushing and sampling process that needs to be undertaken to lift the boil water order. Other situations are handled on a case-by-case basis. We provide these services 24/7/365. To get in touch with someone during an emergency, simply call 1-877-518-5608, the department’s incident reporting line and someone will get back to you. We recognize that water system personnel are basically always on the job or on call, and we will be available to help if needed. Our collective Culture of Health is relentless in this way, and never stops. We have helped water systems through natural disaster events, but also other emergencies that have occurred on or near every major holiday on the calendar. I remember that we lifted a boil water order one time on the day before a major holiday, so the public could enjoy the holiday without the terrible disruption that being under a boil water order represents. As always, thanks for all you do to keep tap water safe in Colorado.

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

Ask Aqua Man

New EPA requirements in the Safe Drinking Water Act

Dear Reg,

Thanks for your questions and for trying to stay up to date! Actually, it was the United States Congress that passed America’s Water Infrastructure Act of 2018. This bill passed both houses of congress by virtually unanimous votes; President Trump signed it into law in October 2018. This new law covers a vast array of water infrastructure matters and makes several important amendments to the Safe Drinking Water Act. EPA, states and public drinking water systems must ultimately implement the changes. Here are a few of the most important items.

It appears that the next (fifth) round of sampling under the Unregulated Contaminant Monitoring Rule (UCMR5) beginning in the early 2020s will require all systems serving between 3,300 and 10,000 people to collect samples. The current UCMR4 requires all systems serving above 10,000 people to sample and only a few smaller systems to sample. This requirement will become effective only if congress authorizes additional funding to support implementation. So the next step will be for EPA to develop specific rules and then wait to see if congress authorizes the additional funding. The UCMR is primarily implemented by EPA with limited support from states.

Community water systems serving more than 10,000 people will be required to provide Consumer Confidence reports at least twice per year and may do so via electronic distribution. EPA has two years to develop specific regulations for this requirement and is also charged with improving readability, understanding and accuracy. This new requirement will be implemented by the states after they adopt the rule. It is likely that this requirement will not be effective until 2022 or so.

Community water systems serving more than 3,300 people will be required to conduct a risk assessment that addresses natural hazards and resilience and review it every five years. An emergency response plan is also required. EPA is required to guidance and technical assistance on how to conduct the risk assessments and prepare the plans. These documents do not need to be submitted to EPA, but a certification that they were completed needs to be sent to EPA by 2020 or 2021. It appears that states will not have a direct role in implementing this requirement, but in Colorado we intend to stay engaged and help water systems via training, etc. as resources permit. EPA is also required to establish a grant program to help water systems improve resilience.

They were quite a few other changes as well, but these are the key changes involving regulatory requirements. Stay tuned for more information in the future.  

-Aqua Man