Program Manager's Message: Secondary Maximum Contaminant Levels (SMCLs)

Colorado’s Primary Drinking Water Regulations (Regulation 11) match EPA’s federal Safe Drinking Water Act in setting both Maximum Contaminant Levels (MCLs) and Secondary Maximum Contaminant Levels (SMCLs). Contaminants with MCLs are often referred to as primary contaminants with primary standards. Contaminants with SMCLs are often referred to as secondary contaminants with secondary standards. Public water systems are required to test for primary contaminants to address situations where primary MCLs are exceeded, ensuring drinking water quality does not exceed any primary contaminant standards. It’s a far different picture for secondary contaminants.

Generally, public water systems are not required to test for secondary contaminants, except for fluoride, which also has a primary MCL. When fluoride levels exceed the SMCL of 2.0 mg/L but not the MCL of 4.0 mg/L, public water systems are required to issue a special public notice due to the risk of dental fluorosis (discoloration and pitting of teeth in children while they are growing under the gums). This is thought to impact the appearance of the teeth but not impact health. 

Manganese is also handled a bit differently. There is a health advisory for manganese in drinking water. The lifetime health advisory to protect against chronic neurologic impacts is at 0.3 mg/L. This lifetime advisory is also used for short-term exposure to infants and children due to their sensitive life stage. The acute exposure advisory for adults is 1.0 mg/L. These levels are significantly above the 0.05 mg/L SMCL for manganese. When the department sees results for manganese above one or both of these health advisory levels, we utilize our authority under the public notice rule to require water systems to notify the public about the health risks. But because there is no primary MCL for manganese, we do not require compliance with the health advisory levels.

However, manganese levels above the secondary standard, which are often accompanied by high iron levels, can make drinking water quality very problematic for customers and water utilities. Customers may sometimes experience black or dark-colored water with sediment. The water can cause problems with appliances and laundry, via staining clothes. For water utilities, high iron and manganese levels can clog distribution piping, reducing available pipe volume and increasing the need for flushing and maintenance. We have seen situations where high manganese and iron levels impact distribution systems so much that significant deficiencies are created. 

In general, customers do not trust or want drinking water that exceeds secondary standards, especially when they can see, smell, or taste the problems. But water utilities and their customers share concerns for the potential cost of addressing this problem. One thing to consider is that problems like this tend to only get worse and more expensive to address over time. Another consideration is pursuing funding assistance. Manganese is considered an emerging contaminant, and we have dedicated funding to help address this issue. If your water utility has manganese, iron, or other problems with SMCLs please reach out and work with us to explore options to address the situation.

Again, thanks for all you do to keep tap water safe in Colorado.

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

Program Manager Message: A reminder about The Significance of Deficiencies!

Hello everyone, 

In the Winter 2009 Aquatalk issue, we ran a Program Manager message about significant deficiencies. This was in the aftermath of the 2008 waterborne disease outbreak in Alamosa, Colorado. We have not had a waterborne disease outbreak at a public water system in Colorado in the 17 years since. Water utilities and the Safe Drinking Water Program have worked together since 2009 to correct thousands of significant deficiencies across the state. But we thought it would be a good time to rerun this article (with a few updates) as a reminder of how important it is to address significant deficiencies and avoid complacency despite our strong recent track record. We have had situations of reported illnesses likely associated with drinking water problems, but the exact combination of epidemiological evidence needed to confirm a waterborne disease outbreak did not materialize. 

The Safe Drinking Water Program periodically conducts sanitary surveys at all public water systems in Colorado. During the survey, we review source(s), treatment, distribution system, finished water storage, pumps and controls, monitoring and reporting data, system management and operation, and operator certification

compliance. The Safe Drinking Water Program believes that the benefits of conducting sanitary surveys include providing compliance and technical assistance, communicating with water systems to better clarify current and upcoming regulations, and conducting a detailed review of all the elements listed above to help ensure that the water system is able to provide safe drinking water to its customers.

After the survey is complete, a sanitary survey report letter is sent to the water system. The sanitary survey letter will notify you if your system has any significant deficiencies. Significant deficiencies are conditions or practices at a water system that may result in the production of finished water that represents an unacceptable health risk to the public. Occasionally, we find situations that represent an imminent, acute health threat to public health. These instances require the immediate attention of both the water system and the state.

However, more typically, the sanitary survey letter will include a specific time frame for the water system to correct the significant deficiency or contact us regarding its plan to correct the significant deficiency. This follow-up is required in the Colorado Primary Drinking Water Regulations. Due to the public health risk that significant deficiencies represent, it is imperative that public water systems correct significant deficiencies and that the Safe Drinking Water Program verifies that these issues are addressed. Section 11.38(3) of the regulations requires a public water system to respond in writing to significant deficiencies and violations from Sanitary Survey reports no later than 45 days after receiving the report. The response must indicate what actions the system will take to address the significant deficiencies and violations noted in the survey letter and include a proposed schedule for completing those actions.

Therefore, I encourage you to locate your last sanitary survey letter from us and review it to see if any significant deficiencies were noted. If there were significant deficiencies, are you sure that they were corrected? I recommend verifying that the deficiencies were corrected and contacting the person who conducted the sanitary survey, if necessary. If the deficiencies have not been corrected, then I recommend contacting the person who conducted the survey and developing a plan to correct the deficiencies. When the deficiencies are corrected, please provide documentation of the correction, including photos, by uploading them to the Drinking Water portal. This will confirm that the deficiency is resolved. 

By working together to identify and correct significant deficiencies, the Safe Drinking Water Program and public water systems can help ensure that the public always receives safe drinking water.

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

Legionella Bacteria and Drinking Water Disease Outbreaks

I attended the American Water Works Association’s (AWWA’s) Annual Conference and Exposition (ACE) in Denver, Colorado, earlier this year. There were some excellent sessions on a wide variety of topics. However, the session that stood out the most to me covered Legionnaires'  Disease and drinking water. Presenters include Dr. Mark Lechavellier, Dr. Chad Seidel, Sheldon Masters, and Julie Kennedy. The session covered some of the latest research into Legionella and drinking water, plus a case study regarding an outbreak in Grand Rapids, Minnesota, that occurred from 2023 to 2024.

Although there are over fifty Legionella species and about half can cause disease, Legionella pneumophila is the most important because it causes most Legionnaires' disease cases and occurs naturally in aquatic environments. The species can infect free-living Amoeba, where the amoeba can act as a host for Legionella. The 1989 drinking water Surface Water Treatment Rule (SWTR) set a treatment technique for Legionella and established a Maximum Contaminant Level Goal (MCLG) equal to zero. Groundwater systems have no such treatment technique requirements, but one-third of the outbreaks occur in groundwater systems. Partly due to better reporting and testing, Legionella cases rose 10-fold from 1990 to 2021. Legionnaires’ outbreaks often occur in buildings such as hotels, medical facilities, and offices. People catch Legionnaires’ disease by inhaling small droplets of water suspended in the air containing Legionella. Legionnaires’ disease does not spread from person to person.

Dr. Lechavallier reported on a Legionella occurrence study that involved water testing 57 utilities. Overall, 9,118 samples were collected, and 1.2% (109) were positive. Thirty-two percent of utilities had detections. A chlorine residual of at least 0.4 mg/L dramatically reduced the positive detection frequency. Dead-end water lines, low water usage, and tank sediment raised the risk of finding Legionella. Flushing can be effective in reducing Legionella levels. Optimum Corrosion Control Treatment (OCCT) reduces pipe corrosion, which reduces the habitat where Legionella can grow. The study concluded that while eliminating Legionella is impossible, testing and management are feasible. Communicating with commercial and industrial customers about Legionella can also be beneficial. 

Unfortunately, Grand Rapids, Minnesota, experienced a severe Legionella outbreak from 2023 to 2024. Grand Rapids has a population of 11,000 and uses groundwater from five wells. The community did not disinfect and had three storage tanks (0.5 million-gallons each) and 81 miles of distribution system. Increased disease incidence began in mid-2023, but water was not believed to be the cause at that time. Legionella were not found in the water system, but the bacteria were found in the water in buildings with Legionnaires’ Disease cases. Over the next year, there were 34 total cases with 30 people hospitalized and two fatalities. After a complete assessment and expert assistance, including Dr. Seidel, chloramination started in June 2024. There have been no Legionella cases in Grand Rapids since then. Considerable effort also involved working with building owners in the town. Generally, buildings that maintain and actively implement water quality management plans do not have outbreaks.

EPA is in the process of updating its rules addressing Microbial Pathogens/Disinfection Byproducts (M/DBPs). It will be a few years before the update is finalized, and these rules will still not apply to groundwater systems. The updated rules are likely to improve the treatment technique requirements for Legionella at surface water systems. While we believe that Colorado is well-positioned to implement improvements due to our rules covering disinfectant residual, storage tanks, and cross connection control (backflow prevention), the occurrence data in this study are concerning. Additionally, even with solid operations by water utilities, important work involving water quality management plans within buildings is not part of our oversight. We encourage utilities to learn more about Legionella and consider partnering with their commercial and industrial customers, especially health facilities like hospitals and nursing homes, to take steps that could reduce the likelihood of a Legionnaires’ Disease outbreak in Colorado.  

As always, thank you for keeping our drinking water safe.

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

➽ Co-Author Chelsea Cotton, P.E. Lead Drinking Water Engineer

Program Manager Message: An Open Letter to the Drinking Water Community - An Opportunity to Say THANK YOU!!!!

Hello everyone, 

In the May 2008 issue of Aqua Talk we ran an open letter of thanks to the drinking water community after the waterborne disease outbreak in Alamosa, Colorado. We have not had a waterborne disease outbreak at a public water system in Colorado in the 17 years since. We thought it would be a good time to rerun this article as a reminder of what happened and how the water utility community came together in response. We have had some disease outbreaks from drinking water, but they have happened in buildings or other situations that did not involve regulated systems. The Alamosa event was the first use of the Colorado Water and Wastewater Response Network (Co-WARN), which has been used many times since 2008 by utilities in need, and those needs have been met by other utilities. So, I say again - THANK YOU!

Article from May 2008: 

In March, the Water Quality Control Division in conjunction with numerous emergency response agencies and city of Alamosa officials were deeply involved in responding to a waterborne disease outbreak within the community. While a definitive identification of the cause has not yet been determined and investigative activities are ongoing, I want to take this opportunity and use this forum to tell everyone involved...Thank you!!

The city of Alamosa and the division could not have accomplished what they did without the assistance and dedication of all the agencies, groups and individuals involved with this response. The request for resources was placed to public water systems though our COWARN network, and the response was overwhelming and immediate. As new resource needs were identified, requests were made, and the resource materialized. Events and circumstances constantly evolved, and the response of the drinking water community was unwavering.

The boil/bottled water order was in place for 23 days and had an impact on the entire community of approximately 9,000 citizens. A staggering amount of work was accomplished within those 23 days including the following:

• An evaluation of the distribution system, including a review of potential cross­ connections.
• A multi-staged systematic disinfection and flushing of the storage tanks and entire 49 miles of distribution piping.
• Extensive monitoring for a number of water quality parameters throughout the distribution system including Salmonella, total coliform, Giardia, cryptosporidium, arsenic, lead and copper, and chlorine residuals.
• The Consumer Protection Division worked with restaurants and other businesses to keep many of them operating during the event.
• Bottled water and bulk water was distributed to residents.
• Communications personnel made substantial public notice efforts with the media to keep people informed.

The drinking water community should be proud of its response.

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

PM Message: Addressing High Nitrate Levels in Groundwater

Last month I attended the annual member meeting of the Association of State Drinking Water Administrators (ASDWA) in Washington, D.C. This group consists of all my counterparts in other U.S. states and territories. It is a great opportunity for me to learn about how other states are working to address similar challenges to what we may be facing in Colorado. This year three states, Wisconsin, Minnesota and Nebraska, shared information about what they are doing to address high nitrate levels in groundwater. Significant portions of these states experience this problem that impacts both community and non-community groundwater systems, plus private wells. Nitrate is known as an acute health risk contaminant for infants. However, more research is being done about chronic impacts as well.

Though our nitrate concerns in Colorado tend to be more localized, we have had a number of water systems exceed the nitrate Maximum Contaminant Level (MCL) of 10 mg/L over time as well. In the 2010s almost 50 communities had a nitrate MCL violation and 65 non-community water systems also had nitrate MCL violations. Fortunately, those numbers are considerably lower so far in the 2020s. A nitrate MCL violation represents a serious challenge for those systems as immediate Tier 1 public notice must be provided advising customers to stop drinking the water. Addressing this issue can be time consuming and expensive. If treatment is needed then ion exchange or reverse osmosis is typically used, which requires a higher level operator for the system and creates a concentrated waste that must be handled and disposed of as well on top of all the added cost for the treatment infrastructure.

Given these concerns, I thought I would share a brief summary of this issue in these states and some of the steps they are taking to address this challenge

Wisconsin is “America’s Dairyland” and #2 state in the country in growing potatoes, which is a nitrate intensive crop. Ten percent of its 800,000 private wells exceed the nitrate MCL which would cost over $400,000 million to replace those wells. Wisconsin public water systems receive 30 to 40 new nitrate MCL violations every year, dwarfing our problem in Colorado. While there is a sense that this problem cannot be fully “solved” in the near future, Wisconsin is taking numerous steps with many partners and projects help with it. Most of these efforts come from their source water protection protection program and include:

• Teacher workshops through universities educating kids about groundwater with specific lesson plans and hands on models
• Nitrogen budget and leaching calculator
• Decision tools that can evaluate application rates
• Developed a well water quality map view with largely private well data
• Evaluating nitrate depth guide drilling to often deeper unimpacted locations
• Numerous projects with with farmers and universities
• Replacing wells

In Minnesota corn and bean crops are main nitrate sources and the southeastern portion of the state with its karst geology is most vulnerable to contamination. Minnesota has fewer violations than its neighbor but last year, 60% of those water systems had to install treatment. Minnesota enacted a new groundwater protection rule that limits fall fertilization applications and is working on a mitigation process in vulnerable areas. The state also developed a number of programs designed to help private well owners and developed simple communication materials. These efforts involve: 

• Well inventory including private wells
• Substantial Outreach/communications including realtors
• Free nitrate testing
• Free treatment available, with 140 reverse osmosis systems installed
• Health-based guidance including:
• New studies showing nitrate association with numerous conditions
• Historical information regarding blue baby syndrome cases in the 1940s

Nebraska recently commissioned a study of nitrate in groundwater showing large areas of the state with nitrate levels above 10 mg/L. They have about 170 public water systems currently  treating for nitrate. Nebraska developed a predictive model to predict how far away a system might be from having a source that exceeds the nitrate MCL and categorized the systems with certain actions:

• 0-3 years out = get started on funding applications
• 3-6 years = provide assistance
• >6 years = Emphasize source water protection

Nebraska offered free testing to private well owners and a rebate program for reverse osmosis treatment systems. They also developed an outreach toolbox with an emphasis on risk assessment.

In Wisconsin and Minnesota EPA got involved to pressure the states to take action to address this acute health risk, and also partnered with the states in the efforts to address it. As you can see, tackling this challenge requires a great deal of effort. I am thankful that we can draw on the experiences in these states to help us when we face similar issues in Colorado. Thank you for your efforts in keeping our drinking water safe.

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

State Revolving Fund Improvements

The State Revolving Fund (SRF) is implementing improvements to the prioritization process that will go into effect in 2025. The goal of these improvements is to ensure that the highest priority projects have the best chance at receiving SRF funding throughout the year. This article covers the upcoming changes and some helpful reminders as you begin preparing your application for funding.

• To receive updates about the SRF Program and reminders about the upcoming eligibility survey, please sign up for the Grants and Loans mailing list here. 

What is changing?

The current process is based on a first-come, first-serve process and does not utilize priority points until the end of the application process. As a result, it can prevent projects that score a high number of priority points from receiving funding because they apply too late in the funding year when funding capacities are lowest. The new prioritization process will implement priority scoring early in the process and provide advance notice of project priority and funding opportunities. The criteria for project scoring can be found in Attachment 1 of the Drinking Water Revolving Fund and Water Pollution Control Revolving Fund Intended Use Plans (IUPs).

Under the new process, priority points will be used to determine when a project may submit a loan application. Projects that score at or above the threshold may apply at any loan cycle during the year. Also, any borrower that qualifies as a disadvantaged community (DAC) is eligible to come in at any cycle. Projects that score below the threshold may only apply at the “Open” cycles. The priority point threshold for the WPCRF program is 100 and the threshold for the DWRF program is 110 points. Applicants will be provided a preliminary score at the prequalification stage and a final score at the project needs assessment stage. Please see the proposed schedule for "Open" and "Limited" cycles:

• January 5th (leveraged) - Open
• February 5th - Open
• April 5th - Limited
• June 5th (leveraged) - Limited
• August 5th - Limited
• October 5th - Limited
• November 5th - Limited

When will this go into effect?

The changes will go into effect in 2025. The current process will remain unchanged until that time. The 2025 IUP’s have been approved by the Water Quality Control Commission and will be posted on the website later this year. A list of FAQs can be accessed here. 

Helpful Tips & Reminders

In order to apply for SRF funds, you have to complete the eligibility survey which is the first step in the SRF process. The eligibility survey should be completed the year prior to be eligible for funding. The eligibility survey for funding in 2025 has been completed. If you are interested in future funding, be sure to complete the 2026 eligibility survey that will be open during the early summer of 2025. You will want to get signed up in the Colorado Environmental Online Services (CEOS) system to access the forms. The eligibility survey is not an application and completing it does not guarantee your project funding.

If you completed the 2025 eligibility survey and are planning on applying for funding in 2025, be sure you complete the Pre-Qualification form which triggers the next step of the process, the pre-qualification meeting. The Pre-Qualification form can be found in CEOS. During your pre-qualification meeting, your project manager will walk you through the loan process and the next steps. Here are links to the loan program steps for the Drinking Water Revolving Fund (DWRF) and Water Pollution Control Revolving Fund (WPCRF) and the main program page. 

If you have any questions about the SRF loan process, feel free to email cdphe_grantsandloans@state.co.us. If you need assistance navigating CEOS or form submission you can contact Angela Garcia  angela.garcia@state.co.us.

➽ Angela Green Garcia, Drinking Water Training Specialist

➽ James Wheatley, Project 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

Program Manager Message: Water Sector Security and Resiliency Road Map

In January 2024 representatives from water and wastewater utilities and the professional organizations along with EPA and the Cybersecurity and Infrastructure Security Agency workgroup released an updated Roadmap to a Secure and Resilient Water and Wastewater Sector. The original roadmap was created in 2009 and then it was updated in 2013 and 2017. The workgroup identified key security threats and vulnerabilities to the water sector and assessed capability gaps in addressing them. The roadmap then identified a number of priority actions to help fill in those gaps. A key theme in this document related to physical, workforce and cyber security was the need to build the culture in the workplace to better understand and protect against threats. 

With respect to cybersecurity, some of the recommended actions include:

• Basic practices for responding to technology failures, being able to operate plants manually in times of need.
• Take basic cybersecurity steps and maintain them, such as password security including routines to change them periodically and removing credentials when employees leave or retire.
• Educate employees about cybersecurity and understand incident reporting requirements.
• Conduct training on how to spot ransomware emails.
• Hold cyber event exercises.
• Advocate for cybersecurity awareness and practices up and down and all across your water system.

We greatly encourage your utility and any associated technology resources that may be located in other agencies such as billing to take steps in these action areas. It’s important to assess the threats and vulnerabilities specific to your utility and its technology assets. After the vulnerabilities are identified and assessed for severity, it’s important to take action to close down those vulnerabilities. This is not necessarily easy, but we can connect you to resources for assistance. This threat is very serious. There have been successful cyberattacks on Colorado utilities over the last few years, including a successful ransomware attack in May 2024. At a minimum, a successful attack can create an immediate crisis at a utility that costs a great deal of time and money. But more serious problems that jeopardize drinking water quality and public health could happen too. We urge you to take steps now and into the future to both prevent attacks on your utility and be prepared to respond if an attack does occur.

Thank you.

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

Final PFAS Rule Considerations

CDPHE PFAs Website

On April 8, 2024 EPA announced that it had finalized a new drinking water rule within the Safe Drinking Water Act (SDWA) to address per- and polyfluorinated alkyl substances (PFAS). This has been a long journey, but now there is a definitive timeline for the state to adopt the rule, public water systems to conduct testing, and if necessary make operational changes or install treatment to comply with the newly established Maximum Contaminant Levels (MCLs). We published an Aqua Talk article on June 21, 2023 about the draft rule published in March 2023 for public comment. EPA received over 120,000 comments on the draft rule that they considered when finalizing this PFAS rule. 

There are several differences between the draft and final rules, but EPA did not modify the Maximum Contaminant Level Goals (MCLGs) or the MCLs for PFOA or PFOS, which are the most common PFAS compounds detected in Colorado. PFOA and PFOS are considered carcinogens, and so the MCLGs were set at zero. This is common for drinking water contaminants. EPA is required by SDWA to set MCLs as close to MCLGs as feasible while considering benefits and costs. The final MCLs for PFOA and PFOS remained at 4.0 parts per trillion (ppt) each based on the reliability of laboratory quantification. 

But EPA established more MCLGs and MCLs for individual PFAS compounds in the final rule as compared to the draft rule. Please recall that MCLGs are the maximum allowable concentration of a contaminant at which no adverse health effects are expected, with a margin of safety. Specifically, EPA added MCLGs set at 10 ppt each for PFHxS, PFNA and HFPO-DA (GenX), which are not regarded as carcinogens. The MCLs for these compounds were also set at 10 ppt each. In Colorado, we tend not to find these compounds at levels exceeding the MCLs unless the MCLs for PFOA or PFAS are exceeded. So, this change is not considered likely to be impactful to compliance status, but can impact treatment design and operations. EPA also made some changes to the hazard Index, but that is not likely to be impactful in Colorado considering the profile of PFAS compounds detected in water samples to date. So, to summarize the final MCLs are:

• PFOA and PFOS MCLs = 4.0 ppt each
• PFHxS, PFNA and HFPO-DA MCLs = 10 pt each

In terms of timing, systems are required to complete initial monitoring within three years, and then begin regular monitoring plus reporting results in the annual Consumer Confidence Reports (CCRs). However, in the final rule, the compliance deadline to meet the MCLs was extended an additional two years to allow for capital infrastructure improvements. This would also allow for two more years to complete public notice requirements for MCLs violations. The public notice tier level remained at Tier 2. 

EPA kept the overall structure of the final rule consistent with the draft rule to model other chronic organic contaminants with quarterly monitoring and compliance based on a running annual average of those results. Reduced monitoring options are available, and it is possible to use prior PFAS data to meet initial monitoring requirements. 

A significant need for EPA guidance on this rule remains to address treatment design and conduction pilot studies, residual waste handling and disposal, reduced monitoring and the trigger level, public notice plus communication, and much more. This is very important to foster state implementation and water system compliance. To that end, EPA recently published a draft revised guidance document for PFAS destruction and disposal for a 180-day public comment period.

The above information describes the federal minimum requirements, and states can choose to take a more stringent approach. As always, we will be engaging stakeholders in developing the PFAS rule for Colorado. The final decisions on Colorado’s PFAS rule will be made by the Water Quality Control Commission after the stakeholder process is completed.  

Most systems that need to install new treatment for compliance will need to secure financial assistance. We have significant funding available now from the State Revolving Fund and Bipartisan Infrastructure Law, plus the PFAS cash fund generated by Senate Bill 2020-218. We can help water systems with testing, planning and design grants plus infrastructure funding as well. These funding sources typically have specific eligibility and grant requirements that need to be met, and our staff can help water systems navigate the process. These funding sources help with initial design and construction activities, but do not help with the long-term operating and maintenance costs. It is not certain whether all these funding sources will be available four or five years from now, so we recommend that systems move forward now with their planning for complying with the new PFAS rule. 

Because we have been helping water systems address PFAS contamination for over eight years, we understand the issues and challenges. We want all systems in Colorado to gain compliance with the PFAS MCLs before the required deadline. I advise you to learn about the final PFAS rule and take steps to prepare your water system for it. If you have not yet collected PFAS samples from your system, I advise you to contact us and we will test your water for free. Getting in front of this now while funding is available is the best approach to keeping tap water safe for your customers. 

Thank you.

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

Program Manager Message: Draft Lead and Copper Rule Improvements (LCRI) Considerations

In late 2023 EPA published its draft Lead and Copper Rule Improvements (LCRI). The intent of this update to the Lead and Copper Rule Revisions (LCRR) is, as the name implies, an effort to improve the nation’s approach to reducing lead exposure in drinking water. The LCRR was the first major update to the Lead and Copper Rule since its inception in the early 1990s. This effort is the first time EPA has tried to strengthen and improve a rule, before many of its compliance dates. This has complicated the approach to certain aspects of the LCRR, such as Lead Service Line Inventory (LSLI) efforts because the LCRI proposes to make some changes to the inventory requirements. The LCRI is currently in the draft stage, with comments due in early February. EPA is planning to finalize the rule in October 2024 and extend the compliance dates for most of the requirements that were initially placed in LCRR. This is not the case for the LSLI requirement, which is still due in October 2024. A bit confusing? Let’s take a look at some key elements, though as we all know, the details involved with lead and drinking water often need painstaking review and consideration. 

The LCRI proposed rule contains several key initiatives that EPA believes will improve upon the LCRR including: 

• Enhanced requirements around Lead Service Line Inventories including more regular updates and adding lead service line connectors to the inventory, plus additional requirements to confirm non-lead status.
• Full Lead Service Line Removal (LSLR) within ten years.
• Modeling the tap sampling requirements after those that Michigan deployed a few years ago that involve using the highest lead result from 1st and 5th liter sample draws.
• Lowering the lead action level from 15 parts per billion (ppb) to 10 ppb.
• Requiring systems with multiple action level exceedance to enhance public outreach and make filters available to the public.

In addition, EPA took state’s implementation concerns with LCRR Specifically, EPA matched the lead testing in schools sampling procedure with its 3Ts Sampling Guidance that schools routinely use. There were also some changes to the “Find and Fix” provisions, which are being renamed and as well as changes to the small system flexibility options.

As with any new rule proposal challenges also lie within the details, and some of the items we are concerned about include:

• Adding connectors into the inventory requirements at this relatively late stage when many systems have already started or completed inventory efforts.
• Requiring pipe loop studies to evaluate corrosion control in more circumstances than necessary, as these studies are difficult, time consuming and expensive to conduct and may not yield better study results.
• Not fully allowing for an alternative approach to Optimum Corrosion Control Treatment (OCCT) similar to the variance that Denver Water received in 2019.

The bottom line is that this rule will still be more challenging than the current lead and copper rule for water systems to comply with and states to oversee. There is a significant need for guidance and training on this rule and its many new requirements. States also need database capabilities to manage all the information and compliance data that will be needed to support implementing this rule.

EPA also estimates that LCRI will involve 38 new reviews by states, the need to develop and utilize at least eight new templates and five new system-state consultations. LCRI will require significant new resources to implement. Colorado implemented several new rules the last decade involving disinfection, water haulers, storage tanks, backflow prevention and cross connection control, and the revised total coliform rule without adding program resources for implementation. However, with LCRI coming in the same year as the new PFAS rule and Consumer Confidence Rule (CCR) revisions, the division must obtain additional resources to support maintaining primacy into the future.  

As always, we will be engaging stakeholders in developing the LCRI rule for Colorado. Fortunately, we learned a lot from moving forward with adopting LCRR and can bring that knowledge to bear on the LCRI rulemaking process. We will work to identify assistance, policy and training needs and strive to help water systems meet the LCRI requirements as best we can considering our funding and resource levels. I suggest that water systems learn about the new draft LCRI rule and take steps to prepare your water system for it. Specifically, will your system be impacted by the changed sampling requirements and lower lead action level? How will your system respond to the requirements involving any test result above the action level? Getting in front of this now is the best approach to keeping tap water safe for your customers. 

Thank you.

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

Risk and Resilience Assessments and Emergency Response Plans

While attending the annual conference of the Association of State Drinking Water Administrators (ASDWA), an organization consisting of my counterparts across the U.S. and including territories, presentations were given about drinking water emergencies that generated national attention. These included the train derailment in East Palestine, Ohio and boil water orders in Jackson, Mississippi. At a previous conference I gave a talk about the Marshall Wildfires. I am sure most of us are aware of the tragic Lahaina, Hawaii wildfire that struck Maui earlier this year.

Extreme events like these are exceedingly difficult to consider and plan/prepare for. But there are requirements in the Safe Drinking Water Act (SDWA) for utilities to assess their vulnerability and risks, and to develop emergency response plans. These requirements came in with America’s Water Infrastructure Act (AWIA) that was signed into law in October 2018. AWIA Section 2013 specifies that all Community Water Systems with populations greater than 3,300 must conduct Risk and Resilience Assessment (RRAs) and Emergency Response Plans (ERPs). These documents need to be reviewed and updated at least every five years. Since this provision of SDWA is directly implemented by EPA, water systems must certify directly to EPA every five years that they have completed these required activities. The initial RRA certifications were due to EPA from March 2020 to June 2021 depending on systems size, so the first five-year updates are due from March 2025 to June 2026. For more information about upcoming review deadlines and requirements please visit the EPA’s RRA/ERP website. The ERP is intended to be developed in a way that addresses system-specific elements based on its RRA, so these certifications are due six months after the RRA certifications.

The RRA needs to address the following components:

• Risks from malevolent acts and natural hazards
• Traditional water system infrastructure resilience including electronic, computer, or other automated systems (including the security of such systems) utilized by the system
• Financial infrastructure
• System monitoring, operations and maintenance
• Chemical use, storage and handling

Note that item two above essentially includes cybersecurity. EPA has a Vulnerability Self-Assessment Tool (VSAT) to help water systems complete their RRA. The Cybersecurity and Infrastructure Security Agency (CISA) and the Colorado Information Analysis Center (CIAC)also provide numerous tools to help systems address the cyber components of the RRA.

After completing the RRA, the ERP needs to be developed and describe strategies, resources, plans and procedures utilities will use to prepare for and respond to emergency incidents. The incidents can be natural or human-caused and range from line breaks to major disasters like floods or wildfires. The ERP needs to specifically address:

• Strategies and resources to improve resilience including physical security and cybersecurity.
• Emergency response strategies and resources
• Proactive approaches to lessen the impact of emergency incidents
• Strategies to help detect malevolent acts or natural hazards that could harm the system

Water systems should coordinate with local emergency planning agencies and must retain copies of their RRA and ERP.

This SDWA provision is not part of state primacy, but is overseen by EPA. To date, EPA has primarily overseen compliance with these requirements via ensuring that systems have submitted their certification. However, going forward EPA is conducting inspections at water systems across the U.S. and soon in Colorado to evaluate compliance with these requirements and help systems become better prepared to prevent emergencies, lessen their severity and respond.

We all know that emergency preparedness is the right thing to do, but it can be hard to prioritize in the face of day-to-day tasks and seeming crises. However, recent events like the emergencies at water systems that have gained national attention and cyberattacks that have involved ransomware and attempts to access control systems should raise our awareness of the value of these efforts. Maybe this information can help you gain support in your utility to keep up with risk assessment and emergency planning activities, especially with respect to cybersecurity. It’s clear that assessing cybersecurity risks and planning to address those risks is part of SDWA, even though EPA’s early 2023 memorandum about cybersecurity and sanitary surveys was rescinded. 

Cybersecurity threats appear to be ever-changing and more threatening. Our Drinking Water Security Response Toolbox is designed to help you meet these AWIA requirements and keep your water systems safe and protected. 

Thank you.

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

Program Manger's Message: Draft CCR Rule Considerations

We recently published an article about the draft PFAS rule published by EPA in March 2023. EPA also published a draft rule in March 2023 to revise the Consumer Confidence Report (CCR) Rule. EPA was required to undertake this action when Congress passed and the President signed America’s Water Infrastructure Act (AWIA) of 2018. AWIA amended the Safe Drinking Water Act and required EPA to revise the CCR rule to:

• Increase the accuracy and readability of CCRs;
• Provide more information about lead;
• Require systems serving more than 10,000 people to provide CCRs twice per year; and,
• Allow for electronic CCR delivery.

EPA also decided to include a provision in the rule requiring states to provide direct compliance monitoring data to EPA as opposed to the current practice of reporting summary information and violations only. We are concerned about this provision leading to EPA micromanaging states with primacy and frequently questioning us about specific water systems that may have issues particularly with per- and polyfluorinated alkyl substances (PFAS) or lead or whatever contaminant may be perceived as a hot topic at the moment.

In reviewing the draft rule we identified some items of concern that the Association of State Drinking Water Administrators (ASDWA) highlighted in its comments on the draft rule. While EPA was certainly required by AWIA to increase the CCR frequency for large systems, specific provisions in the draft rule appear to require water systems to duplicate efforts and communications already undertaken when water systems provide information to the public as part of the Public Notice Rules. We hope EPA elects to reduce those duplicative activities. 

The draft CCR rule also placed a heavy emphasis on translating CCRs into alternate languages and requires states to assist water systems in this process. We support helping people get information they need in a language they best understand. We are happy to assist water systems in achieving this goal. However, we are concerned that the draft rule could be construed as requiring states to undertake translation services in some instances. We believe that EPA must take the lead in helping states and water systems with translation. But states should not be directly required to take on this task by EPA; doing so can create an inherent conflict of interest with states' oversight role. 

Although EPA was tasked in AWIA with improving readability, ASDWA still believes that some of the revised language, such as the nitrate and arsenic education statements, are reading at a 12th -14th -grade level, which is too high for the general public. To improve readability, EPA should simplify much of its new language to a lower reading level. 

EPA also had some concerning language in the draft rule about “misleading statements.” We agree that it is unacceptable for water systems to put misleading statements in CCRs that underplay the health risks from violation or similar circumstances. In Colorado, we review CCRs and require that misleading statements be corrected. However, EPA used an example of a misleading statement as characterizing the drinking water as “safe.” We have serious concerns about this example. Considering that the Maximum Contaminant Level Goals (MCLGs) for many contaminants are zero, we understand that many contaminants can impart a very low health risk even if below the MCL. However, we do not believe that stating the water is safe to drink when a system is in compliance is a misleading statement that must be corrected. 

The timeline for this proposed rule is also concerning. EPA plans to finalize this rule in 2024, and then have it go into effect in 2025. This is not enough time and very challenging from a feasibility standpoint. For most drinking water rules, states have two years to adopt the rule and then the compliance date is one year out from that. Specifically, this is not enough time for states to adopt the rule and attain primacy. This is also not enough time for states to develop the needed policies, guidance, and business processes to support implementation. This is not enough time for states and water systems to develop translation assistance efforts and materials needed. We hope that EPA takes a more reasonable approach to the timing of the final rule.

Lastly, this rule will also require new resources for the division to implement. Colorado has been able to implement several new rules the last decade involving disinfection, water haulers, storage tanks, backflow prevention and cross connection control, and the revised total coliform rule without adding program resources for implementation. However, with this CCR rule coming essentially at the same time as the Lead and Copper Rule Revisions (LCRR) and the PFAS rule, the division must obtain additional resources to support maintaining primacy into the future.  

As always, we will engage with stakeholders in developing the CCR rule for Colorado. We already have a very strong program with respect to public notice, the current CCR rule and translation, especially into Spanish. We will do our best to help water systems comply with the CCR rule considering our funding and resource levels. I advise you to learn about the new draft CCR rule and take steps to prepare your water system for it. 

Thank you,

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

Program Manager's Message: Draft PFAS Rule Considerations

We finally reached the stage where EPA is nearing the completion of the process that leads to a new drinking water rule being added to the Safe Drinking Water Act to address per- and polyfluorinated alkyl substances (PFAS). This has been a long journey, and there is still a ways to go before a rule is in place and implemented. Several years ago two PFAS compounds, PFOA and PFOS, were part of the third Unregulated Contaminant Monitoring Rule (UCMR3). We started working to address PFAS in drinking water in 2016 after we became aware of their presence in drinking water at several communities in El Paso County. Our efforts continued through the 2020 sampling project and today in implementing the updated PFAS health advisory EPA issued in June 2022.

EPA made the decision to regulate PFAS under the Safe Drinking Water Act in late 2021 and in March 2023 published a draft rule for public comment. The draft rule for PFAS establishes Maximum Contaminant Levels (MCLs) for PFOA and PFOS at 4 parts per trillion (ppt) and a novel (at least within the Safe Drinking Water Act) Hazard Index approach to address four more PFAS compounds - PFNA, PFHxS, GenX and PFBS. Of these, PHHxS which is often associated with firefighting foam has been detected most often in Colorado. During its fifth Unregulated Contaminant Monitoring Rule (UCMR5) testing EPA is again sampling for multiple PFAS compounds, so more of these may be addressed in future rule revisions. 

EPA indicated that after the public comment period on the draft rule, it anticipates finalizing the PFAS rule in early 2024. States typically have two years to adopt a final rule, and then the compliance date follows a year of initial monitoring. So the compliance date for this rule would be sometime in 2027 if the normal schedule is followed.

EPA structured this draft rule to model other chronic organic contaminants with quarterly monitoring and compliance based on a running annual average of those results. Reduced monitoring options are available. Violations of the MCL or Hazard Index would result in Tier 2 public notice. We support this approach as compared to a possible approach treating violations as an acute health risk warranting Tier 1 public notice.

There is a significant need for EPA guidance on this rule that addresses treatment design and conduction pilot studies, residual waste handling and disposal, reduced monitoring and the trigger level, public notice and communications and much more. This is very important to foster state implementation and water system compliance. 

We believe that there are many feasibility concerns associated with addressing PFAS contamination in drinking water generally, and these become even more challenging with MCL values set at the practical quantitation limit that many laboratories can reliably achieve. Although the laboratory Colorado has been using can get lower values than the MCLs, this one laboratory will not be able to serve all the water systems that need to test. Lab capacity could become a significant problem, and the turnaround time to obtain results could also become very slow.

This rule will also require significant new resources to implement. Colorado has been able to implement several new rules the last decade involving disinfection, water haulers, storage tanks, backflow prevention and cross connection control, and the revised total coliform rule without adding program resources for implementation. However, with this PFAS rule coming essentially at the same time as the Lead and Copper Rule Revisions (LCRR) and the Consumer Confidence Rule (CCR) revisions, the division must obtain additional resources to support maintaining primacy into the future.  

In addition to feasibility concerns with laboratory capacity and program resources, financial resources for water systems to secure compliance will also be needed. The State Revolving Fund and Bipartisan Infrastructure Law have provided a boost, but this will not be enough funding for all the needed projects. These funding sources help with initial design and construction activities, but do not help with the long-term operating and maintenance costs. For PFAS, residual handling and disposal costs are likely to be high, and these costs will need to be borne by water utilities and ultimately rate payers. Small systems will face special challenges with the costs and need for higher operator certification levels if treatment needs to be installed. 

As always, we will be engaging stakeholders in developing the PFAS rule for Colorado. Fortunately, we have many staff that are experienced with PFAS that understand the issues and challenges, and have been helping water systems address contamination. This will enable us to identify assistance, policy and training needs. We will strive to help water systems meet the requirements of the PFAS as best we can considering our funding and resource levels. Our goal will be to get as many systems as possible into compliance before the required deadline. I advise you to learn about the new draft PFAS rule and take steps to prepare your water system for it. If you have not yet collected PFAS samples from your system, I advise you to contact us and we will test your water for free. Getting in front of this now while funding is available is the best approach to keeping tap water safe for your customers. 

Thank you,

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

Upcoming Regulatory Changes - Recycled from our December 2000 newsletter (Back then it was called Tapping In)

Hello everyone, 

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. At the federal level, the changes in the 2010s were primarily related to the Revised Total Coliform Rule. Colorado was well-positioned for this rule due to our disinfection practices that predated the Safe Drinking Water Act, and then  were further updated by 2016. 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, I hope you enjoy reminiscing about how much progress we have made since this article ran more than 20 years ago. For me, it is difficult to conceive of the Safe Drinking Water Act without the revised Public Notification Rule in particular. What’s your favorite? Can you tell how these planned changes actually transpired or did not happen at all? Thank you.

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

Upcoming Regulatory Changes - Originally published December 2000 

Sandra McDonald Compliance Monitoring and Data Management Unit Manager

EPA is promulgating new drinking water rules in response to the statutory requirements of the Safe Drinking Water Amendments of 1996. The breadth of these rules will change the way the drinking water community does business and the sheer number of new rules make it difficult to stay informed. The Colorado Water Quality Control Division (WQCD) is working hard to be able to provide you with information regarding these rules. This newsletter is one avenue. However, the summaries here are very brief. Some new products being developed by the WQCD will help keep you informed. Additional information will be forthcoming as these initiatives are developed.

As rules are finalized, the department will provide you with additional notification, either through a web site or through the mail. A general summary of upcoming regulatory changes that can be anticipated for the new drinking water rules is provided below. Call (303) 692-3500 with specific questions. In addition, the Safe Drinking Water Hotline is a good source of information at (800) 426-4791. 

Arsenic Rule: 
The Proposed Rule for Arsenic was published on June 22, 2000. The EPA has proposed that the current arsenic maximum contaminant level (MCL) be reduced from 50 µg/1 (parts per billion - ppb) to 5 µg/1. In Colorado approximately 85 to 100 systems may be affected by this proposed reduction in the MCL. EPA's deadline for promulgation of the final rule was extended to June 22, 2001. It is not certain whether the new MCL will be relaxed once the final rule is promulgated. However, there has been a vast outcry from the western U.S. based upon the cost of treating to the 5 µg/1 level. 

Public Notification Rule: 
On May 4, 2000, the Public Notification Rule became final. This rule changes the language that is used to notify the public of violations of the Safe Drinking Water Act. The rule also allows monitoring violations to be recorded in the annual Consumer Confidence Report rather than the normal delayed notification currently required. Colorado anticipates delegation of this rule within the next year. 

Radionuclide Rule:
The Radionuclide Regulation is being revised to set a MCL for uranium as required by the 1986 amendments to the Safe Drinking Water Act. The current MCL's are combined radium 226/228 of 5 pCI/1; a combined standard of 4 millirems for beta emitters; and a gross alpha standard for all alphas of 15 pCi/1, not including radon and uranium. The Radionuclide Rule adds uranium to the list of radioactive parameters being monitored. The uranium MCL is 30 pCi/1 and monitoring will begin in 2002.

Sulfate Rule:
A decision on whether to regulate sulfate is expected in August 2001, with a proposed rule not expected until August 2003. 

Ground Water Rule: 
On May 10, 2000, the proposed Ground Water Rule was published. As proposed, the Ground Water Rule will specify when corrective action (including disinfection) is required to protect consumers from bacteria and viruses. Some of the major elements of this rule would include the requirement that groundwater systems certify that the water is disinfected to a level resulting in 4-log (99.99%) removal of viruses. If the system cannot provide this certification, then all sources must be sampled on a regular basis for coliform and viruses. All systems would be required to conduct and report their daily chlorine residuals on a monthly basis. Any sample results indicating the presence of total coliform would trigger a variety of sampling requirements, including monitoring of a source or additional studies to assure that sources are not contaminated. The final rule is expected in June 2001. 

Disinfection/Disinfection By-Products Rule: 
On December 16, 1998, the final Disinfection/Disinfection By-Products Rule was published. Colorado is working to receive delegation of this rule, and is developing Implementation Guides for water systems. Essentially, this rule requires large and small systems to sample for total trihalomethanes (TTHMs), five haloacetic acids (HAA5s), and total organic compounds. The MCL for TTHMs was reduced from 100 µg/1 to 80 µg/1. In addition, a 60 µg/1 MCL is established for HAA5s. Large systems serving surface water to more than 10,000 people will begin monitoring in January 2002. All other community systems, both surface and groundwater, will begin monitoring in January 2004. It is suggested that systems conduct this analysis prior to the regulatory requirement being imposed so that any potential operational changes might be made prior to the regulatory monitoring being required.

Enhanced Surface Water Treatment Rule:
The Long-Term Enhanced Surface Water Treatment Rule affects water systems serving less than 10,000 people, but requires the same level of compliance. The Long-Term Rule was proposed on April 10, 2000. 

According to the proposed rule, all surface water systems serving less than 10,000 people will be required to monitor for TTHM and HAAS in the warmest month of the year sometime prior to January 7, 2003, and meet levels less than 80% of the proposed standard, or conduct disinfection profiling for giardia. Once this rule is finalized, more information will be provided. 

Radon Rule: 
Radon is a radionuclide that was not included in the previously mentioned Radionuclide Rule, but instead has its own rule. The rule is still not final. Much of the delay has been a result of attempts to find the most inexpensive method to reduce the health risks associated with the presence of radon in public water systems. It turns out that most of the health risk associated with the presence of radon in drinking water results from the vaporization of the radon when water is being used for general purposes such as washing and showering, and its subsequent inhalation by consumers. However, radon is also present in the air of certain homes at levels considerably above the levels that result from the presence of radon in drinking water alone. It also turns out that it is generally much less expensive to treat the air in a home to reduce the concentration of radon than it is to treat the water. Accordingly, the regulatory scheme allows a state to have a higher allowable concentration of radon in the drinking water (i.e., 4,000 pCi/1) if the state has an approved indoor air radon program than if it does not have an approved indoor air radon program. In the event that the EPA does not approve Colorado's program, the MCL for radon could be 300 pCi/1, which would place approximately 85% of the drinking water systems in Colorado in noncompliance. The final rule is expected in December 2000. 

Unregulated Contaminant Monitoring Rule:
The Unregulated Contaminant Monitoring Rule has become final and is to be directly implemented by EPA. Several systems have been notified that they are required to participate in the unregulated contaminant monitoring. All systems that serve water to more than 10,000 people will be monitoring for the unregulated contaminants. Ten of Colorado's small and medium-sized systems have also been selected for this monitoring. For these small and medium-sized systems, the state will conduct the sampling and EPA will pay for the sample bottles, shipment, and analysis costs. The state will receive the sample results of the unregulated contaminants, especially with chemicals such as methyl tertiary-butyl ether (MTBE).