Office of Drinking Water Newsletter

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ODW Now July 2026

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New Nitrate Videos

We are excited to share our new educational videos about nitrate in private well water. The three-part video series highlights:

What is nitrate in drinking water.
How to interpret your test results.
How reverse osmosis systems ensure your water is safe.

All Group A water systems in Washington are required to test for nitrate regularly to ensure it's under the maximum contaminant level of 10 mg/L. Group B water systems must have nitrate levels under 10 mg/L when developed, but testing requirements vary from county to county, with no ongoing sampling requirement in state regulations.

When nitrate levels are above 10 mg/L pregnant women, infants, and people with preexisting lung and heart conditions may be especially at risk. One of the biggest concerns with high nitrate levels is methemoglobinemia, also known as blue baby syndrome. Ingesting high levels of nitrate reduces the ability of red blood cells to carry oxygen. These red blood cells rapidly return to normal in most adults and children, but not in babies.

Nitrate is also a contaminant of concern across the state of Washington, and we encourage all Group B water systems and private well owners to test for nitrate and coliform at least once a year.

Please share the videos with your network to spread the word and encourage residents to test their drinking water.

Chlorine Monitoring Tips and Pitfalls

The ability of public water systems to deliver safe drinking water relies on operators using a multiple barrier approach for possible contaminants. Source protection, treatment, distribution system maintenance, and disinfection all play an important role in the multiple barrier approach of providing safe and reliable drinking water. Chlorine is used both as treatment for a known source contamination and the distribution system protection with a chlorine residual.

Taking daily chlorine residual readings may begin to feel monotonous over time; however, the small chlorine residual number from the test kit provides valuable insight into the entire water system's health. Therefore, chlorine residual readings can be more than a regulatory requirement, it is also a powerful diagnostic tool.

Source water can change day-to-day, or week-to-week, causing chlorine demand to change. Generally, at a constant chlorine dose, when chlorine demand increases, the chlorine residual should decrease. Understanding conditions that affect chlorine demand assists you to identify developing problems early, when it is easier to correct them and before customers feel that water quality is decreasing.

Chlorine Residual = Chlorine Dose – Chlorine Demand

What is chlorine demand? When chlorine is added to water some of the chlorine reacts with organic matter, microorganisms, metals, and other substances present in the water. Chlorine demand is the amount of chlorine that is consumed by these reactions during the initial contact time. Once chlorine completely oxidizes, then “breakpoint,” is reached. Any additional chlorine becomes active free available chlorine—a powerful disinfectant.

There are many instances where chlorine could be completely consumed, leaving little to no residual at the end of the distribution system.

Naturally occurring ammonia
Biofilms and microorganism growth in pipes and storage tanks
Broken or leaking water lines
Increased sediment in water lines and reservoirs
Backflow incidents
Oversized water mains or storage tanks
Periods of lower water usage leading to water stagnation

Over time, bacteria and other microorganisms can build up on distribution system pipe walls forming a protective layer known as biofilms. These biofilms consume chlorine and make it difficult to maintain adequate residuals throughout the system, especially at far ends of the distribution system. A decreasing residual at a consistent monitoring location could be an indicator of biofilm growth, broken water lines, or a cross-connection.

For this reason, you should record and learn what is normal for your system. If a location that typically has a residual of 0.80 mg/L suddenly reads 0.20 mg/L, you should not ask simply, “Did I meet the minimum requirement?” The deeper question is: “What changed?”

Familiarity with your water system and typical residuals can better help you locate the root cause of the declining residual. Could your water system benefit from a flushing program? Do you need to increase the chlorine dose? Are there other variables interacting with the chlorine demand?

Just as important as taking the sample is taking it correctly. Every water system should have a Standard Operating Procedure (SOP) and follow the manufacture’s recommendation for their equipment. Know the different procedures for Total and Free chlorine residual and use the correct sample cell vials for the chlorine residual reading. Consistent procedures help ensure readings are accurate and comparable over time.

Common Chlorine Monitoring Pitfalls

Inconsistent chlorine dosing. Chlorine feed pumps can fluctuate significantly over time. Be sure to conduct a pump drawdown test on a regular basis. Chlorine strength can also decrease over time, especially if you are using a high strength (12.5 percent) solution.
Sampling location. Consider establishing multiple monitoring points at representative locations throughout the distribution system, as well as the required sampling location. Ensure the sampling locations are not next to the chlorine injection point, since this will show higher chlorine residual.
Equipment or method issues. Verify that the chlorine residual test kit meets EPA method 33. Take good care of the equipment by following the manufacturer’s recommendations and handle the instrument with care. Make sure that your device is on the proper setting (some devices have low, mid, and high range settings).
- Colorimetric test strips and Color Wheels are not allowed to be used.
- Be sure you are measuring and reporting Free Chlorine residual readings.
Sample cell vials. Have extra on hand for when a vial breaks or becomes stained. Never leave the sample water in the sample cell vial. Rinse with water three times before taking the sample and after the sampling is complete. Contrary to what the Hach instructions say, if you are using a Hach device, you should use the same vial to zero your device and measure the residual.
Interference. Some water quality characteristics, including manganese and certain corrosion control products, may interfere with residual readings, providing false high or false low values. There are alternate measurement methods you can use if you think this is the case.
Poor documentation. Record results consistently and to the correct decimal. Document to the hundredth (0.81 mg/L rather than 0.8 mg/L). Small changes can provide important clues about the health of the water system.

Daily chlorine residual monitoring can feel repetitive, but it remains one indicator available to water system operators. Early detection of leaks, water quality issues, or distribution system deficiencies can improve long-term water quality and customer satisfaction. It can also create a sense of pride for the operator in providing consistent delivery of clean, reliable drinking water.

The next time you perform a chlorine residual test, remember; you’re not just collecting a number, you can be a water system detective gathering data about the health of your entire distribution system.

Stemming the Rising Silver Tsunami

Due to waves of retirements in the water industry, there are increasing numbers of operator vacancies. Not just at the larger utilities—smaller water systems also find themselves struggling to replace their certified operator in charge of their water system. Water systems find it difficult to keep up with the rising costs of everything from infrastructure replacement to staff salaries.

To help ease this growing demand we created the Waterworks Operator Job Postings webpage. We update it weekly and list postings in descending order, newest to oldest.

Water systems provide vacant position information through an application form that includes links to the online position description.

Some water utilities use our job posting page to advertise entry-level positions, which encourages interest in water system operations as a career path.

Please check out the Waterworks Operator Job Postings webpage for more details and a list of current position openings.

Drinking Water Advisory Group (DWAG) September 14, 2026, Meeting

We hold all our meetings through Microsoft Teams video, so you can join our meeting with your computer, laptop, tablet, or phone from wherever you are. You can find the Teams links and meeting agenda on our DWAG Meeting webpage. After the meeting we post any handouts or presentations and, within a month, we post the meeting notes.

Do you want to receive advance notice of meetings and their agendas? Join our advisory group email list. Do you have questions or topics you want to discuss? Email John Freitag or DWInfo@doh.wa.gov.

A Tale of Two EPA Rule Changes—PFAS

On May 20, 2026, the U.S. Environmental Protection Agency (EPA) added two proposed changes to the Federal Register for comment. The comment period is open through July 20 for both the proposal to rescind the regulatory determinations for PFHxS, PFNA, HFPO-DA (GenX) and the hazard index (HI), and the proposal to provide an option for water systems to extend the date treatment is required.

Recission of PFHxS, PFNA, GenX, and the HI

The Washington State Board of Health adopted the 2024 PFAS rule and the MCLs into state regulation, so Washingtonians will continue to receive these important protections regardless of any future changes to the federal rule.

While PFOA and PFOS make up most of detected PFAS, the MCLs covering the other PFAS protect people from exposure to chemicals known to cause cancer, disrupt hormones and immune systems, impair reproduction, and harm child development. These regulations are necessary to protect public health and limit greater exposure and harm to public health. If finalized, the EPA proposal would remove these federal requirements, yet our existing state regulations ensure these public health protections remain in place.

The Proposed Extension Introduces Multiple Compliance Tracks

EPA proposed the extension option to provide a process for their own implementation before states obtain primacy. However, we plan to submit our primacy package soon.

The Safe Drinking Water Act already provides a well-established tool for water systems that are facing compelling compliance challenges. The existing system-specific compliance agreements and variances currently available are sufficient to address legitimate challenges for public water systems that cannot meet MCL compliance by April 2029.

There are additional considerations related to EPA's proposed compliance extension. One is the potential effect on funding opportunities. The Infrastructure Investment and Jobs Act includes funding for emerging contaminants that is currently appropriated through 2026. Delays in identifying and implementing mitigation projects could limit some public water systems' ability to take advantage of this funding, potentially increasing costs that would otherwise have been offset by federal assistance. Smaller and disadvantaged water systems may be affected the most.

Another consideration is that the proposed extension could be interpreted as an opportunity to delay planning or mitigation activities. However, the extension does not eliminate existing responsibilities or the need to prepare for future compliance. Delaying action could reduce opportunities to use available federal funding and postpone implementation of measures to address PFAS.

The extension options also introduce new requirements that differ from our established processes and may require additional clarification during implementation. The proposed rule requires water systems seeking an extension to certify that they are taking steps to meet the standard and have already entered into financial agreements to implement these steps. In addition, any PWS with any single PFOA or PFOS result ever equal to or above 12 ppt must provide multiple control measures until the mitigation is complete, such as providing an alternative for clean water (POU, POE, bottled water, pitcher filters), developing environmental source control agreements, public education, and community outreach.

We plan to continue our normal processes available in the SDWA for systems that can’t meet the deadlines. If your system exceeds and you have not considered mitigation options, now is the time. We have funding options available on our Drinking Water State Revolving Fund (DWSRF) webpage. This is the FINAL year for the supplemental emerging contaminant remediation funding that was made available under the Bipartisan Infrastructure Law. For small and disadvantaged communities, DWSRF will continue to have funding available through the EC-SDC grant. For funding questions, please contact our DWSRF Environmental Engineer, Jocelyne Gray at 564-669-4893 or our Emerging Contaminants project manager, Tara Moore at 564-263-0483. If you are interested in free technical assistance regarding PFAS response or planning needs, please fill out the Technical Assistance Request Form.

You have until July 20 to submit comments to EPA. Our recommendations include a request for EPA to expand technical and financial assistance to help public water systems meet existing compliance deadlines.

NEW! OpCert Exams in Español

The lower certification levels of the 2025 standardized Waterworks exams are now in Spanish. Approved applicants can schedule their Waterworks exams in Spanish for WDM 1 and 2; WTPO 1 and 2; WDS, and BPAT certifications.

Check our Exam Resources webpage for updated 2025 “Need-to-Know” criteria and the formula conversion table in Spanish.

Rising Temperatures, Falling Strength: Managing Sodium Hypochlorite Storage This Summer

As summer temperatures rise, so does the risk of sodium hypochlorite degradation: A hidden challenge that can quietly undermine disinfection performance and regulatory compliance.

Liquid sodium hypochlorite (NaOCl) solution is widely used across water systems as the most common choice for drinking water disinfection. However, it is inherently unstable and degrades over time, especially at higher (12.5 percent) strengths. Degradation and the weakening of the sodium hypochlorite concentration occurs with warmer temperatures and other factors. We are forecasted to have a 60-70 percent chance of above-normal temperatures across Washington state for the summer; therefore, it is critical for you to consider where and how you’re storing sodium hypochlorite.

Why should degradation be considered? Degradation decreases the strength of the sodium hypochlorite solution. This makes it difficult when calculating and implementing the appropriate chemical dosage to meet required target chlorine residuals. Degradation can impact consistent operation of the chlorine metering pump and may result in varying doses and chlorine residuals. This can specifically impact systems that are required to achieve 4-log inactivation or CT6.

While warmer temperatures heavily accelerate degradation, there are also other factors to consider. Proper storage methods can help slow the rate of degradation. The following are our recommended best practices. It should be noted that these are not separate options, but should all be done in coordination.

Temperature Control

Ensure that both the sodium hypochlorite chemical injection tank and bulk supply are kept in temperature-controlled rooms or cool environments. The target storage temperature should be approximately 60°F (15°C). The rate of decomposition roughly triples for every 10° C (18° F) increase in temperature. Avoid storage in direct sunlight, or any other ultraviolet (UV) light sources.

Storage Time

Avoid extended onsite storage times. There are many reasons why a water system will choose to store bulk liquid sodium hypochlorite. To name a few: buying bulk can be more cost effective, it can increase operational efficiency with less frequent deliveries and can ensure a reliable stock by avoiding unforeseen supply chain delays. However, sodium hypochlorite decomposes to produce oxygen, chlorate, and perchlorate over time. Shorter storage times help minimize the formation of these contaminants and guarantee more consistent concentration. Some larger systems will limit their storage to a 30-day onsite supply, finding that is an appropriate turnover for the sodium hypochlorite. Water systems should evaluate their own turnover time to avoid excess inventory but also ensure operational reliability.

Dilution

Dilute higher strength solutions upon delivery using good-quality softened water. Most suppliers offer sodium hypochlorite as a 12.5 percent concentration. However, higher concentration solutions are known to degrade at a much faster rate. Storing 12.5 percent sodium hypochlorite can also lead to the production of perchlorate. Perchlorate is an endocrine disrupting chemical that disturbs the human thyroid system. Perchlorate is formed in hypochlorite solutions as hypochlorite decomposes, where higher hypochlorite concentrations produce larger concentrations of perchlorate.

With the appropriate storage methods and practices, liquid sodium hypochlorite is a great way for water systems to offer consistent disinfection and ensure public health in these upcoming summer months and beyond.

More Resources

After the Flames: Why Wildfires Can Affect Drinking Water Long After the Smoke Clears

Washington’s 2026 wildfire season is already underway. The Libby Creek Fire, reported in May in the Okanogan-Wenatchee National Forest, is an early reminder that wildfire preparedness is not only a fire-response issue. For drinking water systems, wildfire can create operational and water-quality challenges long after flames are contained.

A fire does not need to burn directly through a treatment plant or water system facility to create drinking water concerns. Wildfire can damage power supplies, pump stations, storage tanks, distribution lines, access roads, and communications systems. It can also change the surrounding landscape in ways that affect source water. After a fire, ash, sediment, debris, nutrients, and other materials may move rapidly into streams, reservoirs, and surface-water intakes during rainfall events.

The first major rain after a fire can be as important to a water system as the fire itself. Burned soils may absorb less water, increasing runoff, erosion, and turbidity. For systems that rely on surface water, this can increase treatment demands and create challenges with filtration, chemical use, solids handling, and monitoring.

Wildfire can also affect the distribution system itself. If heat, damage, or pressure loss affects pipes and other infrastructure, contaminants may enter the system. In these circumstances, a boil-water advisory may not be the appropriate protective action. Depending on the hazard, a water system may need to issue a Do Not Drink or Do Not Use advisory while it assesses damage, collects samples, and works with public-health partners to determine when water is safe again.

What Water Systems Can Do Now

Know your system’s wildfire vulnerabilities. Identify facilities, wells, tanks, pump stations, electrical connections, chemical storage, source-water intakes, and access routes that could be affected by fire or evacuation restrictions.

Maintain storage and backup power. During high-risk fire weather, systems should consider maintaining full storage where feasible, confirming generator readiness, and coordinating with fuel suppliers before an emergency occurs.

Prepare customer communications in advance. Water systems should have clear, ready-to-use messages for boil-water, do-not-drink, and do-not-use situations. The message must match the hazard. Boiling water may help address certain microbial risks, but it does not remove chemical contamination.

Plan for the recovery period. Following a wildfire, monitor source-water conditions and prepare for runoff, erosion, turbidity, and debris. Systems should also document damage, repairs, resource requests, staff time, equipment use, and operational decisions.

Coordinate early. Notify local emergency responders and the Washington State Department of Health if a wildfire affects system operations, infrastructure, access, or water quality. Water systems can also use mutual-aid arrangements, such as Washington Water/Wastewater Agency Response Network support, when available.

Wildfires may begin as a fire-management emergency, but their effects can become a drinking-water emergency. The most effective response begins before the smoke arrives: knowing the system’s vulnerabilities, preparing for loss of access or power, and planning for the water-quality impacts that may follow.

For Washington drinking-water-system wildfire preparedness and response resources, visit our Wildfires and Safe Drinking Water webpage.

Celebrating our 2025 TOP Award Winners

Introducing Our New Quarter Century Award!

For 25 years, Washington’s Rapid Rate Filtration Plants have been steadily raising the bar in water quality. These filters are critical for removing particles—called turbidity—from drinking water. Lower turbidity means stronger protection from harmful microbes and better public health for everyone.

Every month, treatment plants across the state submit turbidity data through their operations reports. We review the results and then enter the highest daily values into a computer program called the Optimization Assessment Software. This tool lets us compare systems statewide and track performance improvements over time.

Three systems are continuing their run of excellence and have reached a significant milestone of 25 consecutive years of optimization! This is a tremendous feat to celebrate!

And the 2025 Results are In!

Surface water treatment plants using conventional and direct filtration are once again exceeding regulatory standards. In other words, they’re not just meeting the minimum—they’re going above and beyond to deliver safer water to Washington communities. The latest graph of Rapid Rate Treatment Plant Performance Trends 2001–2025, shows steady progress overall as a group. Improved turbidity results mean cleaner water, stronger public health protection, and more resilient systems.

Congratulations to all of our 2025 award recipients! By optimizing water quality produced by their existing facilities, these systems are achieving higher-quality water, providing a bigger margin of safety, and building greater resilience for the future.

Quarter Century Award

Arlington Water Department (2001-2025)*
Lake Whatcom Water and Sewer District—South Shore Water System (2001-2025)*
Pasco Water Department (2001-2025)*

Twenty-Year Award (20 to 24 years of continuously optimized performance)

City of Kelso (2006-2025)*

Platinum Award Recipients (15 to 20 years of continuously optimized performance)

River Bend Water System (2009-2025)
City of Yakima (2010-2025)
City of Bellingham (2011-2025)*

Gold Award Recipients (10 to 14 years of continuously optimized performance)

Castle Rock Municipal Water (2012-2025)
Town of Metaline Falls (2012-2025)
Department of Energy/200 W (2015-2025)
Hoquiam Water Department (2015-2025)
City of Anacortes (2016-2025)*

Silver Award Recipients (Five to nine years of continuously optimized performance)

Friday Harbor (2017-2025)
City of Port Angeles (2019-2025)
Seattle Public Utilities (2019-2025)
City of Leavenworth (2020-2025)
Roche Harbor Water System (2020-2025)
City of Everett Public Works Department (2021-2025)*
City of Ilwaco Water Department (2021-2025)*

Bronze Award Recipients (Three or four years of continuously optimized performance)

Carbonado Water Department (2022-2025)
Island View LUD 9 (2022-2025)
City of Tacoma (2022-2025)
City of Chelan Water Department (2023-2025)*
Ryderwood Improvement Service (2023-2025)*

*Consecutive certificate award recipient for 2025.

Congratulations to all water treatment plants that were optimized in 2025!

What is Turbidity? Turbidity is a measure of how cloudy water looks. The cloudiness comes from tiny particles like silt, clay, and organic matter. While turbidity itself isn’t dangerous, high levels can make it harder to remove or disinfect microbes that could cause illness. That’s why keeping turbidity as low as possible is a key step in protecting public health.

Cybersecurity and the Drinking Water Sector: Understanding Emerging Risks and Available Resources

Cybersecurity is one of the fastest-growing risks facing the drinking water sector. As water systems increasingly rely on operational technology, remote monitoring, cloud-based services, and interconnected business systems, cyber incidents have the potential to affect utility operations, emergency response activities, public confidence, and, in some cases, drinking water service delivery. EPA and the Cybersecurity and Infrastructure Security Agency (CISA) continue to emphasize that cyber threats targeting critical infrastructure, including water systems, remain an ongoing concern.

The drinking water sector historically focuses on physical infrastructure risks such as natural disasters, equipment failures, contamination events, and aging infrastructure. Today, utilities must also consider cyber threats that could affect treatment processes, monitoring systems, communications, billing systems, and operational decision-making. While many cybersecurity incidents begin as information technology (IT) issues, the increasing integration of operational technology (OT) means that cyber incidents can have real-world operational consequences.

Recent EPA efforts demonstrated the scope of the challenge. In February 2026, EPA reported that it proactively identified cybersecurity vulnerabilities at 277 drinking water and wastewater systems during 2025 and worked with utilities to eliminate more than 350 vulnerabilities. These vulnerabilities ranged from weak authentication practices and insufficient access controls to operational technology systems that were unnecessarily exposed to the internet. EPA noted that many corrective actions involved low-cost or no-cost improvements, highlighting that systems of all sizes can gain achievable, meaningful cybersecurity gains.

Why Cybersecurity Matters to the Drinking Water Sector

Modern water systems depend on technology to monitor treatment processes, control pumps and valves, track tank levels, manage alarms, and maintain communications with operators. Cyber incidents can affect a utility's ability to monitor system conditions, access critical information, communicate with customers, or respond effectively during emergencies.

Operational technology systems such as Supervisory Control and Data Acquisition (SCADA) systems, Human Machine Interfaces (HMIs), and Programmable Logic Controllers (PLCs) are increasingly targeted by cyber actors because they provide direct access to infrastructure operations. Cyberattacks against these systems can disrupt operations, force utilities into manual operations, damage equipment, or reduce situational awareness during critical incidents. EPA has emphasized that cyberattacks on drinking water and wastewater systems have the potential to threaten public health and community resilience.

Emerging Threats and Recent Examples

Federal agencies continue to warn that nation-state actors and other malicious cyber groups are actively targeting critical infrastructure sectors.

In April 2026, EPA, CISA, the FBI, and the National Security Agency issued a joint cybersecurity advisory warning of ongoing Iranian-affiliated cyber threats against U.S. organizations, including the water sector. The advisory highlighted attempts to target internet-connected operational technology and programmable logic controllers commonly used throughout critical infrastructure sectors. Federal partners encouraged organizations to strengthen cybersecurity protections, limit internet exposure of operational technology, and review remote access practices.

One recurring concern involves internet-exposed programmable logic controllers and other operational technology devices. Previous incidents involving Unitronics PLCs demonstrated how attackers can exploit devices that remain accessible from the internet or use default credentials. These incidents reinforced a key lesson for the water sector: basic cyber hygiene practices, such as changing default passwords and limiting external access, remain among the most effective defenses.

EPA and CISA have also highlighted the risks associated with internet-facing HMIs and SCADA components. When operational technology systems are directly accessible from the internet, attackers may gain visibility into utility operations or potentially interfere with normal processes. As utilities adopt new technologies and expand remote access capabilities, understanding and managing these risks becomes increasingly important.

Common Cybersecurity Challenges

Many cybersecurity vulnerabilities identified within the water sector are not the result of sophisticated attacks. Instead, they often stem from common challenges such as:

Weak or default passwords.
Lack of multifactor authentication.
Unpatched software and firmware.
Excessive remote access permissions.
Internet-exposed operational technology.
Limited asset inventories.
Insufficient network segmentation between IT and OT environments.
Lack of cybersecurity incident response planning.

EPA's cybersecurity assessments have repeatedly shown that addressing these foundational issues can significantly improve a utility's cybersecurity posture. In many cases, the most effective improvements involve strengthening access controls, reducing internet exposure, maintaining accurate inventories of connected devices, and improving incident response preparedness.

Supporting Cyber Resilience in the Water Sector

Cybersecurity is not solely an information technology issue. For water systems, cyber resilience is increasingly becoming an operational resilience issue. Just as utilities prepare for floods, earthquakes, wildfires, and infrastructure failures, they should also prepare for cyber incidents that could affect their ability to provide safe and reliable drinking water.

EPA and CISA continue to encourage utilities to adopt a layered approach to cybersecurity that includes preventive measures, detection capabilities, response planning, recovery procedures, and regular staff training. Federal partners also stress the importance of exercising cybersecurity response procedures and understanding how operations would continue if key systems became unavailable.

As cyber threats continue to evolve, maintaining awareness of emerging risks and available resources will remain an important component of supporting resilient drinking water systems.

Free Resources and Training Opportunities

EPA Cybersecurity Resources

Cybersecurity Response Resources

Includes advisories, webinars, response guidance, and information on operational technology threats affecting the water sector.

Cybersecurity for the Water Sector

EPA's central cybersecurity webpage for drinking water and wastewater utilities. Including guidance documents, planning resources, technical assistance opportunities, training information, and cybersecurity best practices.

Water Sector Cybersecurity Evaluation Program

Provides free cybersecurity assessments and technical assistance to drinking water and wastewater utilities to help identify and address cybersecurity vulnerabilities.

Cybersecurity Response Resources

Offers cybersecurity advisories, incident response resources, operational technology guidance, recorded webinars, and information on emerging threats affecting the water sector.

Cybersecurity Exercises and Technical Assistance Courses

EPA's complete schedule of upcoming cybersecurity trainings, webinars, exercises, and technical assistance opportunities.

Free Upcoming EPA Technical Assistance and Exercises

Water Cybersecurity Assessment Tool (WCAT) Webinar

Cybersecurity Procurement Checklist Tool Training

EPA 2026 National Cyber Drill

Insider Threat Mitigation Webinar

CISA Resources

Cybersecurity and Infrastructure Security Agency (CISA)

Provides cybersecurity guidance, threat information, vulnerability assessments, incident response resources, and critical infrastructure support.

Cybersecurity Performance Goals (CPGs)

A prioritized set of cybersecurity practices developed by CISA to help organizations improve cybersecurity resilience.

Cyber Hygiene Vulnerability Scanning

A free service that helps organizations identify internet-facing vulnerabilities and potential cybersecurity weaknesses.

Cybersecurity Advisors (CSAs)

Regional cybersecurity experts who provide technical assistance, assessments, planning support, and cybersecurity guidance to critical infrastructure partners.

For additional cybersecurity guidance and assistance, water systems can also coordinate with EPA, CISA, state primacy agencies, and other water sector partners to identify resources that support cybersecurity planning and resilience efforts.

Get Ahead of Your Sanitary Survey: A Self-Inspection Guide

How to Conduct Your Own Pre-Survey Inspection

Public water systems have undergone routine sanitary surveys for more than 30 years. After several rounds of surveys statewide, both operators and regulators gain a better understanding of best management practices for system operation, maintenance, and financial viability. We may still find significant deficiencies, but less often on repeat visits. Through sanitary surveys and technical assistance, we've worked together to improve the safety and reliability of our state's drinking water.

Now it's time to apply those lessons by doing self-surveys. Use your last sanitary survey report as your guide. If your self-inspection turns up a deficiency, fix it right away. Don't wait for your next scheduled survey.

Scheduling self-surveys throughout the year, as part of routine O&M, means a safer water supply for your cusotmers and fewer deficiencies found during your next official survey. Keep written logs of your self-inspections and any maintenance performed, along with a photo record of reservoir roof openings.
Routine self-inspection is how you protect public health and set yourself up for a smooth, successful sanitary survey.

Follow These Steps Before Your Next Sanitary Survey

Inventory structures and materials within 100 feet of your wells and 200 feet of your springs. Identify microbial and chemical contaminant threats and be ready to discuss your plan to eliminate or mitigate them during the survey. See Sanitary Control Area Protection 331-453 (PDF) for guidance.
Inspect your well, spring, and storage tank facilities. Verify the integrity of seals and screens over any pathway contaminants could use to enter the well casing, spring box, or tank interior. See Simple Fixes for Wellhead Openings 331-232 (PDF) for guidance.
Physically disconnect any treatment process or source not listed on your water facilities inventory. We'll let you know when you can reconnect it.
Photograph anything we may not be able to access, such as the finished water tank roof. Photos should confirm that seals and screens on roof vents, access hatches (open and closed), overflows, and level-gauge wire entry points are in good condition. See Sanitary Protection of Reservoirs—Vents 331-250 (PDF) and Sanitary Protection of Reservoirs—Hatches 331-249 (PDF) for guidance.

Make sure your water system has:

Reasonable security measures protecting the well house, pump station, and storage tank from unauthorized access and vandalism.
An air gap and screen on the finished water tank overflow pipe outlet.
A raw source water sample tap on each source of supply.

Check the pump and well house to ensure:

No openings allow animals or insects to enter.
Pumps and controls operate properly and are adequate to prevent chronic outages or premature pump failure.

For treatment, ensure:

Any chemical added to drinking water is NSF-approved for potable use.
There is an air gap or USC-approved reduced pressure backflow assembly (RPBA) on any hard-piped supply coming into the chemical solution tank.

For RV sewage dump stations, make sure:

There is an approved RPBA on the water supply to the dump station.
A state-certified backflow assembly tester has tested it within the past year.

Be Aware of These Common Deficiencies

If your self-inspection turns up any of the items below, fix it as soon as you can. Don't wait for your next sanitary survey.

Sources

Openings in the wellhead.
Potential contaminants in the Sanitary Control Area.
Emergency sources physically connected.
No raw water sample tap.
No security protection.

Reservoirs

Hatch cover not sealed properly.
Improper vent construction.
Vent screen missing or openings too large.
Overflow screen missing or damaged.
No security protection.

Treatment

Chemicals not NSF/ANSI 60 approved.
Not working properly.
Cross-connection at chemical solution tank.
No post-treatment sample tap.

Pumps

Unscreened discharge on pump control valve.
Over-cycling of pumps.
Pumphouse structures in poor condition.

Management

No Coliform Monitoring Plan.
No Emergency Response Plan.
No O&M Procedures.
No Cross-Connection Control Program.
Plans out of date and not implemented.

Focus: Water Storage Tanks

Improperly sealed storage tanks are one of the most common deficiencies found during sanitary surveys and a significant cause of microbial contamination that can lead to health advisories. You should inspect storage tanks at least annually.

Sanitary surveyors aren't allowed to climb many types of storage tanks during site visits, which is why we require photos showing proper protection on all tank roof openings. Photos must be less than a year old.

Hatch photos must show a gasket or seal, a lock, and an overlapping cover.
Vent photos must show construction and screening.
Overflow photos must show they are screened and properly constructed to prevent entry of contaminants.
Drain photos must show location and area of discharge.
Other openings must show that they're properly sealed.

Stagnant water from low turnover is another common storage tank problem, which can lead to unsatisfactory coliform samples. Address this by modifying the inlet-outlet configuration or adjusting operating procedures to improve turnover and mixing.

Keep your Operations and Maintenance Manual current, and document maintenance activities, including photos, for your own records. Regular preventive maintenance extends the life of your storage tank, saves money, and protects public health.

The Truth About Bleach

Best practice is to use a disinfectant certified to NSF/ANSI Standard 60, though WAC 246-290-220 allows an exception for commercially retailed hypochlorite bleach with no additives. That exception is getting harder to rely on. Most bleach sold today for laundry and cleaning contains additives that are not safe for human consumption including scents like lemon or lavender, gel additives such as splash-less or splash-free formulas, or other laundry technologies like Cloromax. Make sure your bleach is free of additives and consider using bleach that is NSF/ANSI 60 certified. The NSF Product listing website recommends bleach products certified as NSF/ANSI/CAN Standard 60. See our Bleach Guidance 331-763 (PDF) for more information.

Did you know?

The Sanitary Survey Checklist 331-487-F (Word) used in most sanitary surveys is available online, complete with bolding and highlighting that flags deficiencies. Use it for your self-inspection, so there are no surprises.

You can look on Sentry to find out when your next sanitary survey is due. If you need a copy of your last sanitary survey report, contact us.

You Have Resources

Evergreen Rural Water of Washington (ERWOW) circuit riders are available to help. ERWOW is a non-profit dedicated to training, technical assistance, and advocacy for drinking water and wastewater utilities. Reach out to them for a pre-survey inspection.

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What to do About a Repeat Offender—Harmful Algal Blooms

Tri-Cities Columbia River Cyanotoxin Monitoring

The Cities of Kennewick, Pasco, and Richland will continue their Columbia River cyanotoxin monitoring activities during the 2026 algal bloom season. The project began in 2021 following animal deaths linked to anatoxin-a in the river. Cyanobacteria (also known as blue-green algae) can produce cyanotoxins such as anatoxin-a in water.

In general, blue-green algae “blooms” usually are easily visible because they most commonly float and appear as greenish or bluish-green paint on the surface of the water. However, cyanobacteria in the Columbia River grows on underwater rocks close to the shoreline (known as “benthic” algae). The benthic cyanobacteria are not easily detected because there is no visual clue on the water surface, and that is why the Tri-Cities, DOH, and Benton-Franklin Health District teamed up to start a routine cyanotoxin monitoring program.

Each of the intakes for the surface water treatment plants serving the Tri-Cities are being tested for anatoxin-a and microcystins throughout the May-November season. In addition, all three cities add permanganate as a pre-oxidant prior to their primary surface water treatment facilities. Permanganate is more effective at neutralizing anatoxin-a than standard chlorine treatments. No cyanotoxins have been detected in the treated water from any of the Tri-Cities treatment plants.

Cyanotoxins are an emerging, unregulated contaminant linked to climate change. We expect the number of systems facing this issue to increase—all systems with a surface source should start planning now. Our guidance publication Dealing with Cyanobacteria: Time to Make a Plan 331-654 (PDF) has tools to help you.

Things to Consider

Evaluate your existing treatment processes—how well could your treatment plant weather a cyanotoxin event? What treatment adjustments can you make? Do you have an alternative source?
Engage your decisions makers—what resources do you need? How will you keep your customers informed?
Line up laboratory capability—how many samples will you need and how quickly can you get sample results during an emergency?
Develop a robust communication plan to maintain credibility with your customers and ensure you can “Be first. Be right. Be credible”.

You can find more resources on our Harmful Algal Bloom Toolkit webpage.

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