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WaterOperator.org Blog

Articles in support of small community water and wastewater operators.

Peracetic Acid (PAA) in Wastewater Disinfection

Peracetic Acid (PAA) in Wastewater Disinfection

Peracetic acid (PAA) has grown in popularity over the last several years for its use in the disinfection of wastewater and stormwater. Utilities use disinfectants as the primary mechanism to inactivate and destroy pathogenic organisms that spread waterborne disease. An appropriate disinfectant will sufficiently treat any disease-causing microbes including bacteria, spores, helminthes, and protozoa. While PAA technology has been employed in Canada and Europe for the last 30 to 40 years, this disinfectant has only become noticed in U.S. municipal wastewater treatment within the last 10 years. Competing with chlorine, an already well-established disinfectant, its use is still slow growing, however systems are discovering that PAA offers several benefits to wastewater treatment that chlorination does not.

What is peracetic acid? The alternative disinfectant is a clear, organic peroxide compound that readily hydrolyzes to acetic acid and hydrogen peroxide in water. It’s characterized as a strong oxidant and fast reacting disinfectant. Commercially available peracetic (CH3CO3H) is purchased in an equilibrium mixture of acetic acid (H3CO2H), hydrogen peroxide (H2O2), and water (H2O). Manufacturers typically add a stabilizer as well. The following formula represents the equilibrium equation: CH3CO2H + H2O2 ←→ CH3CO3H + H2O.

PAA can generally be purchased in concentrations of 5% to 22%. When PAA decomposes in water, free hydrogen peroxyl (HO2) and hydroxyl (OH) radicals are formed. These radicals have significant oxidizing capacity that play an active role in microbial disinfection. According to the EPA, bacteria are destroyed through cell wall lysis and leakage of any cellular constituents.

Wastewater systems consider moving to peracetic acid for several reasons. Unlike chlorine, PPA decomposes into biodegradable residuals of vinegar (acetic acid) and hydrogen peroxide that can pass fish toxicity tests without removal. These residuals are not toxic, mutagenic, or carcinogenic. Bioaccumulation in aquatic organisms is also highly unlikely. Neither chlorinated compounds nor harmful disinfection by-products (DBPs) are produced with its use. As such, PAA has been considered the potential answer to tough DBP regulations. Peracetic acid can also disinfect over a wide range of pH and is unaffected by nitrate and ammonia concentrations.

Chemical handling of PPA is toted for being easier and safer than chlorination. The disinfectant can be stored for long periods of time exhibiting less than 1% decrease in activity per year when properly stored. Its use does not require any special risk management plans (RMPs) required by the EPA when handling certain toxic chemicals. For systems that operate under cooler conditions to prevent contamination or elevated temperatures, PAA has a low freezing point. Switching to PAA requires minimal retrofitting with the chemical itself being offered at prices competitive to other disinfectants.

There can be some disadvantages to peracetic acid. Depending on the formula purchased, PAA introduces varying amounts of acetic acid into the wastewater effluent. This can contribute to biological oxygen demand (BOD) and may not be appropriate for systems that are struggling to meet these limits. The biggest challenge wastewater systems face is regulatory approval. While PAA has been approved by the EPA as a primary disinfectant, each state regulatory agency must also approve its use. A WaterOnline guest column includes an infographic of states that have approved PPA as of 2017. The guest column discusses how systems can approach local regulatory agencies to seek approval on a case-by-case basis.

The overall effectivity of PPA will depend on wastewater characteristics, the PAA concentration, contact time, and the reactor configuration. Dosage will depend on the target organisms, wastewater quality, and level of inactivation required. When monitoring PAA residuals, operators can use the same analyzer and method as for chlorine residuals. A standard EPA sampling method does not yet exist. The lack of established methods and protocols for PAA makes approval difficult for local regulatory agencies. To help investigate the use and implications of PAA in wastewater, the Water Research Foundation (WRF) completed a study to evaluate effluent toxicity as well as dosage and contact times required to meet compliance. Metro Vancouver’s Northwest Langley WWTP in Canada has also published findings from a multi-year pilot program that used PAA as a disinfectant. More studies will have to expand on existing research until peracetic acid can become easily and widely adopted.

Featured Video: How to Use a Hydrant Sampler

Featured Video: How to Use a Hydrant Sampler

Through the use of a hydrant sampler, operators can monitor water quality at various points in the distribution system without the need for access to indoor taps from local businesses or residential homes. Sampling hydrants allows operators to protect public health by routinely collecting bacteriological samples required by their regulatory agency. Operators should sample along the distribution system at the locations and frequency specified by their RTCR sample siting plan. For assistance in developing or updating your sampling plan, check out the EPA documents Sample Siting Plan Instructions (download) and the Revised Total Coliform Rule (RTCR) Sample Siting Plan with Template. Please check with your Primacy Agency to determine if stricter requirements may apply to your system.

In this week’s featured video, the U.S. EPA’s Area-Wide Optimization Program demonstrates how to use a hand-built hydrant sampler on dry barrel hydrants to collect water quality samples throughout the distribution system. The procedures used  in this video, including how to calculate flush time and how to build a sampler, can be found at the EPA’s Hydrant Sampler Procedure and Parts List web page. Calculating an appropriate flush time is important to yield sample results that accurately characterize the quality within your distribution system. The hydrant sampler from the video can be built with parts from your local hardware store however, since 2018 AWOP has created a new sampler design that requires less parts making it cheaper to build and easier to use. Check out this week’s featured video to find out the best practices and safety concerns for using a hydrant sampler.

Using Reed Beds for Sludge Treatment

Using Reed Beds for Sludge Treatment

The use of reed beds in both central and decentralized wastewater treatment systems can offer a low cost and energy efficient opportunity to process sludge. Originally developed in Germany, the practice was brought to the United States in the 1980s. Under this technology, a variety of marsh grass, also known as Phragmites, is planted in reed beds built with concrete walls and lined with an impermeable layer to protect groundwater. TPO magazine suggests using a concrete bottom because PVC liner can be easily damaged during maintenance. The beds themselves contain a porous, finely aggregated media such as sand or recycled glass (pg. 12). This media allows the reeds to grow and excess liquid to pass through an underdrain system connected to the head of the plant for recycling. Risers can help distribute and load the sludge.

After the reeds have been established during a period of roughly three months, sludge can be loaded into the beds every three weeks. As the plants’ extensive root structure absorbs sludge moisture, water will be released through leaves and into the atmosphere via evapotranspiration. The microbes found in the root rhizome will help the sludge continue to break down. During the winter months when the reeds are dormant, the freeze-thaw cycle will allow liquid to easily separate from sludge to continue dewatering. When spring arrives, the reeds will return to their active growing cycle.

According to TPO Magazine, reed beds can adequately manage facilities that treat up to two million gallons per day provided that the required land is available. The reeds themselves can handle climates that experience several weeks of freezing temperatures during the winter. Before temperatures drop too low, operators will typically burn off the reeds in the fall. Alternatively, the reeds can be composted or disposed in a landfill. After approximately 8 years, the solids must be removed. At this time, the beds will be taken out of service in the summer and given an additional 90 days to dry out. Once the sludge is removed, the reeds will need to be re-established. A presentation by the Constructed Wetland Group provides a detailed overview of how to perform maintenance on reed beds.

While this technology is low maintenance and energy efficient, there are still pros and cons. As an advantage, reed beds can help to remove heavy metals from sludge. This should be considered during reed harvesting. As a drawback, constructing new beds requires significant capital costs, however utilities may be able to convert existing sand pits or drying beds to reduce costs. TPO Magazine notes that unpleasant odors can emerge during the spring when winter ice melts. Many scientists also worry that wastewater facilities using non-native grasses can encourage the establishment of invasive species. Phragmites spread predominantly through their underground rhizomes, laterally growing stems with roots. Furthermore, when non-native grasses escape into a new area, they can easily take over since their native competitors aren’t present. Facilities should practice careful harvesting and monitor the integrity of their bed structures to ensure containment. Despite these drawbacks, reed bed systems can be a successful and efficient form of sludge treatment even in comparison to conventional treatment methods.

Featured Video: How To: Develop a Cross-Connection Control Plan

Featured Video: How To: Develop a Cross-Connection Control Plan

A well-developed cross connection control plan ensures that backflow events are an infrequent occurrence in drinking water distribution systems. Cross connections involve any connection between treated water and untreated water. The connection can allow for backflow and ultimately drinking water contamination.  You can learn about the two types of backflow, backpressure and backsiphonage, as well as how they occur in RCAP’s 2018 blog on Cross Connection and Backflow Prevention – Underutilized Protection for Potable Water. Additionally, WaterOperator.org has featured two backflow videos in a previous blog that will help you learn more about the phenomenon.

To prevent unnecessary contamination in your distribution system this week’s blog post features an RCAP video on how to develop a cross connection control plan. This short video describes the key administrative and technical provisions that should be included in your plan. We’ve also highlighted some useful resources that can help you follow their suggestions. If you'd like to find state or territory specific resources such as a sample ordinance or cross connection control plan template, visit our document library 

 

Now that you know the key provisions to a successful backflow prevention program, check out these additional resources. Remember that many state or tribal territories can have their own rules and specifications that need to be met by your utility. Consults with your system's primacy agency before starting or updating a cross connection control program.

Backflow Prevention – Idaho Rural Water Association
This 2-sided brochure can be used to educate your customers about potential sources of backflow and the impacts of contamination.

Residential Cross-Connection Questionnaire – Alliance of Indiana Rural Water
This 2-page questionnaire can be set to customers to identify potential sources of cross connection.

Selling Cross-Connection Control to Management- University of Florida Center for Training, Research, and Education for Environmental Outcomes
This power point, presented by Ron Chapman, describes how you can encourage your utility to implement a cross connection control program.

Cross-Connection Control Manual – U.S. Environmental Protection Agency
This manual has been designed as a tool for health officials, waterworks personnel, and plumbers to understand the basics about backflow prevention, preventer testing, and control programs.

Professional Recognition Opportunities for Water & Wastewater Operators

Professional Recognition Opportunities for Water & Wastewater Operators

Water and wastewater operators in responsible charge are required to hold an operating license issued by their primacy agency equivalent to or greater than the classification of their treatment system. This certificate ensures that the operator has demonstrated the skills and knowledge necessary to operate and maintain their facility. Each primacy agency sets its own licensing requirements, ultimately targeted at safeguarding public health and the environment.

In addition to a primacy issued license, there are many operators that look to other forms of professional certification to set themselves apart from their peers. While there are a variety of ways to demonstrate excellence in the industry, many operators enjoy the format of professional certificate programs. These programs are not often recognized by primacy agencies, however they demonstrate that an operator has taken the initiative to learn more about their field and develop additional skills that can be utilized in operations, treatment, or management.

Shaun Livermore is an operations manager of the Utilities Authority for the Parch Band of Creek Indians. He recently obtained Utility Management Certification with Water University. After taking the program Shaun concluded that the certificate is a good tool to help operators make the jump into management. He notes that, the utility management certification does give me validation that I have the knowledge to be in utility management. It is also a way to demonstrate that to others. The requirement of degrees for higher level positions at utilities is often a barrier for highly capable individuals that could more adequately perform the duties of the position. This practice will continue to change moving into the future, but affordable programs like this one and Professional Operator designation will be a way to measure the aptitude for upward mobility of developing operators. It is something that I hope to see on more job descriptions in the future.   

Programs like these often require more training than the average operator license. Upon request, some states may allow the training to be used toward an operator's certification. If you’re interest in a professional certificate, we will review a few programs available to water operators in this blog.

Professional Operator (PO)
Provider: Association of Boards of Certification – Certification Commission for Environmental Professionals (C2EP)
About: The PO certificate was the first professional designation created for operators. To earn the PO title, operators must pass a certification exam and meet specific educational and professional experience requirements.
Certificate Options: Certificates include water treatment, distribution, collection, and wastewater treatment. Each option consists of four certification classes ranging from Class I to Class IV. The highest class reflects the highest level of job complexity and operational requirements.
Certificate Requirements: Each OP class has different certification requirements. Check them out here.
Cost: As of now, the application ranges from $145-$195 while the exam costs $67. This cost does not factor in the continuing education training that could be necessary to meet PO certification qualifications.
Re-certification: Required every 2 years.

Water University’s Utility Management Certification (UMC)
Provider: National Rural Water Association
Certificate Options: Utility Management Certification
About: The Utility Management Certification is the first professional certificate to recognize an operator’s knowledge and skills in the management of a water or wastewater utility. The certification program is designed to evaluate a participant’s education, work experience, and training.
Certificate Requirements: The certification process starts when an applicant submits their education, industry experience, and training history. Each experience is assigned a point value that must ultimately add up to 100. Once an operator confirms their 100 points, they will take a certification exam.
Cost: The program costs $250 in addition to any training necessary to meet the 100 points of experience that might not already be met.
Re-certification: Renewal is required every 3 years and costs $125. Certificate holders must complete 40 hours of additional training. After five renewals the certificate does not expire.

WQA Water Treatment Industry Professional Certification
Provider: Water Quality Association (WQA)
Certificate Options: Certificates types include water specialist, master water specialist, and water treatment representative.
About: The WQA certification is a voluntary credentialing process that can demonstrate an operator’s commitment to higher education, professional growth, and customer service.
Certificate Requirements: To achieve any WQA certified designation, the candidate must complete the appropriate course work, pass a comprehensive exam, and abide by the WQA Code of Ethics for the Water Quality Improvement Industry.
Cost: Enrollment costs $315-$815 which includes a 1-year subscription to the learning modules required for certification. The exam ranges from $145 to $320.
Re-certification: Certificates must be renewed every three years. Re-certification requires a renewal fee and to have obtained three approved credits during the certificate cycle.

There are an increasing number of professional certificate opportunities available to the water industry. These programs are growing in diversity, focus, and program format. As operators look to these programs for development, they should identify a program that will be best suited to their previous experiences and future career goals.

Resources to Complete Your Risk & Resilience Assessment and Emergency Response Plan

Resources to Complete Your Risk & Resilience Assessment and Emergency Response Plan

Drinking water utilities should be aware of the risk and resilience assessment (RRA) and emergency response plan (ERP) requirements mandated by section 2013 of the America’s Water and Infrastructure Act (AWIA) of 2018. Under section 2013, community water systems (CWS) serving populations of 3,300 people or more are required to perform a risk assessment using the results to develop or update their ERP. The due date to certify the completion of these requirements is dependent on the population served by the system. If a CWS provides water to a consecutive system, they must include the population of the consecutive system in the total population served. 

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*After submitting the RRA, the ERP must be submitted and certified within six months. Community water systems will be required to review and revise, as necessary, their RRA and ERP every five years after the initial certification dates. 

These new AWIA requirements amend section 1433 of the Safe Drinking Water Act (SDWA), originally created from the Bioterrorism Act of 2002. The Act focused on incidents of terrorism and required CWS’s serving more than 3,300 people to conduct a vulnerability assessment (VA) and develop an ERP. The new AWIA requirements place an emphasis on the risks of malevolent acts, natural disasters, and cybersecurity. Since the vulnerability assessments from the Bioterrorism Act are now more than 10 years old, AWIA approved the destruction of these assessments. Utilities that want their VA returned instead can submit a request letter to the EPA before the due date of their risk assessment.

To assist in meeting the new requirements, the EPA has developed several resources designed specifically for AWIA. Resources and tools are uploaded on this EPA web page as they become available. The risk and resilience assessment is the first requirement due under section 2013 and necessary to develop your ERP. The assessment must include six criteria. Following the assessment, the ERP must include four criteria in addition to any state requirements. In this blog we will provide information about these AWIA resources in addition to other documents that can be useful to complete your RRA and ERP. 

EPA's AWIA Resources:

Resiliency and Risk Assessment:

Emergency Response Plans:

Other Helpful Resources to Get Started:

Resiliency and Risk Assessment:

Emergency Response Plans:

To certify the completion of your RRA or ERP, the EPA has developed guidelines for certification submittals via their secure online portal, email, or mail. If your system needs any additional help to meet these requirements, the EPA will be hosting in-person and online training sessions for each region. If these document suggestions don’t meet your system needs, check out our document library to find a variety of resources on risk assessment and emergency response.

Featured Video: Wastewater Treatment -Troubleshooting Aeration Basin

Featured Video: Wastewater Treatment -Troubleshooting Aeration Basin

This week’s blog features a wastewater troubleshooting video by the YouTube account Wastewater Operations Channel. The account is run by Jon Kercher, an operator of 10 years who uploads educational videos filmed during the work day at his wastewater treatment plant.

In this video, Jon demonstrates how to troubleshoot a disparity between two air legs within an aeration basin that should be equal flow. The problem was noticed when the basin was put into lead position. This video not only demonstrates how to troubleshoot a flow disparity, but teaches a great methodology for troubleshooting any wastewater treatment issues. Jon notes that while we have a general tendency to gravitate our troubleshooting toward process parameters, we must also consider monitoring parameters as well. Watch his video to find out what was causing the flow disparity!

Developing an Asset Management Program

Developing an Asset Management Program

Asset management is a critical component to the short and long-term success of every water and wastewater utility regardless of size or system type. When a system understands the condition of its assets, in addition to present and future projected needs, the utility can make informed decisions about infrastructure operations, management, and investments. These decisions will minimize expenditures, equipment failures, and risk to public health while promoting reliability, resiliency, compliance, and customer satisfaction. Asset management moves utilities from reactive to proactive decision making and allows systems to get the most out of what they have.

If your facility has never developed an asset management plan or it’s been quite some time since you’ve last revised your plan, we’ve highlighted our favorite resources to get you back on track. A well-developed plan includes asset inventories, operation and maintenance tasks, emergency response and contingency planning, comprehensive financial plans, succession planning, and an understanding of current and future service level goals. Without addressing the technical, managerial, and financial management of your system, your plan will be incomplete. So without further ado, here’s our favorite resources to help you improve your understanding of asset management and develop your own program.

What is Asset Management?

Developing an Asset Management Plan

Writing Your Plan

Additional Help: Asset Assessment, Financial Planning, and Program Review

Developing a new plan can seem like an intimidating project, however utilities will ultimately improve their services and decision making capacity while saving time, resources, and money. If your system needs help developing or assessing a program, check out the EPA’s list of technical and financial assistance providers or contact WaterOperator.org to have help finding a provider. The EPA maintains a list of capacity development contacts that can answer any questions about specific requirements of your primacy agency.

To find additional information on asset management, visit our resource library. You can use the category filter to narrow down your search by topics in asset management, financial management, utility management, and more. Our library can also be filtered by resource type such as manuals, videos, or templates. The other filter options can refine your results to a specific host organization or state. Check out our tutorial to use the library to the best of its capabilities.

An EPA Guide for Climate Resiliency Planning

An EPA Guide for Climate Resiliency Planning

Many utilities are developing plans to increase short-term and long-term climate resiliency in response to extreme weather events, changing water availability, or the risk and resiliency assessment requirements set forth in the America’s Water Infrastructure Act of 2018 (AWIA). To assist in the early developmental stages of resiliency planning, the EPA's CRWU program designed the Resilient Strategies Guide for Water Utilities. This online application prompts utilities with a series of questions about their system and its resiliency concerns to provide recommend strategies that will decrease vulnerability. This web application was updated in August 2019 to allow utilities to specify their system size and find funding sources for the projects they want to pursue.

Both water and wastewater systems can use the tool. The foundation of the guide is built using the CRWU Adaptation Strategies for Climate Change and a funding list maintained by the Water Finance Clearinghouse. Completing the guide takes roughly 20 minutes. After answering a series of questions that identify your system type, size, location, assets, preferred resiliency strategies, and funding interests, the application will produce a report that can be used as a starting point to develop a more complex plan.

Once the guide is launched, you will start by answering questions about your facility and its resiliency priorities. The priorities indicate the concerns that your system wants to address. You can filter the list of priorities in the left hand menu to narrow your focus to topics such as drought preparation, flood protection, energy efficiency, etc. The ‘More Info’ button will elaborate on any option you're considering. Once you’ve selected your priorities, you’ll indicate what assets are present within your system. From there you can select your preferred planning strategies that have been suggested based on your previous answers. Filter the strategies with the left hand menu to narrow down your options by cost or category. For example, if you want to exclude strategies that require new construction, you could check the ‘repair & retrofit’ category instead. The last section recommends potential funding sources that might assist with the strategies you've selected earlier.

The strategies and funding sources will be used to generate the final report. Continue to the end and select ‘Generate Report’. This report will include a detailed summary of your answers, contact information for any funding sources you've selected, and case studies relevant to your utility. To save a copy of the report you will have to copy and paste the results into a Word document. If you have a CREAT account, you can select ‘Export CREAT File’ to download a file that can be imported into your CREAT account’s existing analysis. CREAT (Climate Resilience Evaluation and Awareness Tool) is a more in-depth risk assessment and planning tool that can be used once you've done your initial research. You can preview the CREAT tool framework with their guide here.

Developing & Implementing a Cost Effective Water Utility Safety Program

Developing & Implementing a Cost Effective Water Utility Safety Program

Even with advances in smart water technology, any supervisor knows that a utility can't run without its dedicated staff. While workers take care of equipment operations, maintenance, billing, or customer service, it's the responsibility of the person in charge to ensure these duties are being carried out in a safe environment using appropriate precautions.

Water and wastewater utilities have a history of experiencing occupational injuries, illnesses, and fatalities (IIF) at a higher rate than most other occupations. The Bureau of Labor Statistic’s Incidence Rates - Detailed Industry Level table from each year’s Industry Injury and Illness Data Summary Tables has generally supported this trend. Their reports show the average non-fatal incident rate for the water and sewage industry has historically been higher than the industry average as a whole.

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The data from this table was taken from the Bureau of Labor Statistics Incidence Rates- Detailed Industry Level for 2008 and 2017. (Click table to enlarge.)

The table above shows the rate of non-fatal injuries reported by the Bureau of Labor Statistics in 2008 and 2017. While any year can have variability, in 2008 the non-fatal injury incident rate was much higher than the industry average. In 2017 you can see that the average number of injuries has decreased since 2008 and is now closer to the industry average. These values don’t include the number of fatal injuries experienced by the water and wastewater industry, but as an overall trend, non-fatal injury reports to the Bureau of Labor Statistics support that the water industry has improved since the early and late 2000’s.

Types of Injuries
As utilities continue to prioritize and promote a safe work culture, we hope to reduce the frequency of incidents even further. There are many hazards that pose a risk to operator safety. The most frequent non-fatal water and wastewater injuries reported by the Bureau of Labor Statistics in 2017 were due to over exertion during lifting, being struck by a tool or object, and falls, slips, and trips. Water and wastewater utilities also have to manage the risks posed by confined spaces, electrical equipment, trenching, road safety, ladders, hazardous chemicals, blood borne pathogens, and more.

Safety Costs
According to Bureau Veritas’ presentation at the 2008 CSWEA Maintenance and Safety Seminar, the financial costs for water and wastewater injuries can be quite expensive. Budgeting for a good safety program will protect your employees and incur less expenses than the direct and indirect costs that result from a poor safety program.

Developing and Implementing a Safety Program
Since every system faces different hazards, your safety plan should be specific to your system hazards. To get started, the Occupational Safety and Health Administration (OSHA) recommends seven core elements for your system’s safety program: management leadership, worker participation, hazard identification and assessment, hazard prevention and control, education and training, program evaluation and improvement, and communication and coordination for host employers, contractors, and staffing agencies. OSHA’s Recommended Practices for Safety and Health Programs website provides an explanation of these elements in addition to a list of helpful tools, case studies, additional resources, and a download for the recommended practices guide.

We also encourage you to check out the Water Research Foundation’s Water Utility Safety and Health report to review safety program best practices and cost evaluations for various proactive and reactive programs. Once you’ve done your research, West Virginia Rural Association has developed an Injury and Illness Prevention Program template that systems can expand from.

Water System Specific Hazards
As you continue to promote safety in the work place remember that complacency is the adversary to injury and accident prevention. More specific  guidelines for electrical safety, traffic control, hazardous material communication, competent persons, confined space, chemical handling, chlorine exposure, fires, and waterborne disease can be found in Chapter 8 of the Alaska Department of Environmental Conservation’s Intro to Small Water Systems Correspondence Course. The OSHAcademy also offers a variety of water and wastewater specific safety training. If you have a different safety question, more resources are available at WaterOperator.org’s document library or under our blog post category Operator Safety.