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WaterOperator.org Blog

Featured Video: Interviewing Basics Webinar

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In this week’s blog post, we’d like to feature an excellent webinar recording hosted and published by CA Water Pros with the California Water Environment Association and California-Nevada Section AWWA. The webinar introduces both incoming water professionals and those seeking new industry positions to some interview best practices that will help any operator stand out above the competition during a job hunt. The webinar is presented by Todd Novacek, Director of Operations at the Moulton Niguel Water District. Todd frequently interviews professionals for the District and started putting together popular interview questions with his favorite answers when his son received his Water Distribution II certificate.

From the video job seekers will learn how their social skills, attire, attitude, honesty, and pre-interview research can make all the difference in a first impression. Todd stresses the importance of gauging an audience and making every interview question count. You’ll learn popular questions that can likely be expected during an interview at a water district. These questions will help you start thinking of your own answers now. Remember that questions can vary with utility size, location, and job requirements. As Todd emphasizes, you should know the facility you’re applying to before the interview. Even when you feel that you’re already the best candidate for the job, practicing and preparing beforehand will demonstrate your dedication to the position.

Once an operator fulfills their certification and educational requirements, interviewing at utilities can seem like a completely different challenge that neither training workshops nor any workbook has adequately prepared them for. This one hour webinar is worth the time and will help operators start a new aspect to their professional development, interviewing.

Managing Dissolved Oxygen in Activated Sludge Plants

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Sustaining optimal dissolved oxygen levels in activated sludge plants is necessary for biological treatment of organic material and ammonia. While raw wastewater often contains some amounts of oxygen, aeration systems can increase dissolved oxygen (DO), mixing, and the suspension of microbes through mechanical agitation or diffused aeration. Aerobic microorganisms use this oxygen to breakdown organic waste into inorganic byproducts. The amount of dissolved oxygen consumed by microbes during biological treatment is referred to as biochemical oxygen demand (BOD). According to an article by Triplepoint Water, approximately 1.5 pounds of oxygen is consumed for every pound of BOD oxidized. To oxidize one pound of ammonia, that value increases to 4.57 pounds of oxygen. Most plants aim to maintain around 2 mg/L of DO which allows microbes contained within the center of floc to receive oxygen.

Wastewater operators should regularly monitor oxygen availability in the form of dissolved oxygen. Insufficient oxygen levels will allow aerobic and nitrifying microbes to die and floc to break up. At DO concentrations under 1 mg/L, the potential for filamentous growth increases. On the other end of the spectrum, too much oxygen increases power consumption and, at very high levels, inhibits settling. Research has estimated that aeration can use up to 45 to 75% of a treatment facility’s overall electricity use. With an online DO analyzer equipped to automated controls, the EPA reports that energy costs can be reduced by as much as 50%.

Where and when an operator samples for DO will be determined by the requirements written in the facility’s National Pollutant Discharge Elimination System (NPDES) permit and basic process control. To compare dissolved oxygen levels throughout the day, samples should be collected at the same location. The Ohio EPA’s Activated Sludge Process Control and Troubleshooting Chart Methodology recommends that systems sample within 1-2 feet of the surface water near the discharge of the aeration tank into the clarifier. By collecting multiple samples in the same location throughout the week, operators can reliably determine if DO concentrations are sufficient for treatment while developing a DO profile. In addition, measuring DO at multiple depths and locations in the aeration tank can help find dead spots.  

To supply adequate DO, the Ohio EPA manual includes how to determine blower runtime based on organic loading and system design. We should  still note that temperature, pressure, and salinity can all influence the solubility of oxygen. Additional sampling locations can include the raw wastewater, aerobic/ anaerobic digester, and final effluent. Final effluent with high dissolved oxygen can cause eutrophication in the receiving waters, however low DO can harm aquatic organisms. Some permits set a minimum DO level for effluent to ensure aquatic organisms have the necessary oxygen levels to sustain life.

While every technique and tool has its strengths and weaknesses, operators can measure DO through a Winkler Titration test (see Michigan DEQ Laboratory Training Manual pg.91), electrochemical sensor, or optic sensor. The two sensors mentioned can be purchased as portable handheld meters or stationary devices. For automated blower control and continuous sampling, an online sensor is used. For NPDES compliance monitoring, measurements must be taken through an EPA approved method at the frequency specified in the permit.

When using any DO sensor, the EPA’s Field Measurement of Dissolved Oxygen (SESDPROC-106) procedures require that the equipment be well maintained and operated per manufacturer instructions. Upon initial purchase, probes should be inspected, calibrated, and verified for accuracy. During each additional use the instrument should be calibrated and inspected again. The EPA recommends checking instrument calibration and linearity using at least three dissolved oxygen standards annually. All maintenance and sampling activities should be documented in a logbook per NPDES requirements. Any time a measurement is taken, the temperature of the water and any notable wastewater conditions should also be recorded in the logbook. 

Dissolved oxygen is a frequently monitored parameter in wastewater treatment systems. Operators should have a firm understanding of how dissolved oxygen is involved in wastewater processes and how they can manage DO to achieve compliance. Check out our online document library to find useful resources to learn more.

Featured Video: What is Water Hammer?

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Any water or wastewater operator should possess a strong understanding of water hammer and the implications it can have on piping systems. Water hammer, also referred to as hydraulic shock, occurs when there is a sudden change in flow velocity or direction that results in a momentary increase in pressure. If high enough, the pressure can cause damage to pipes, fittings, and valves. An example where water hammer can occur is when an operator rapidly closes a valve halting flow and sending a shockwave through the system. In Jefferson City, MO, operators responding to a ruptured water main created a second break during repairs as a result of water hammer. Pressure surges can also occur through unexpected power outages or equipment failures.

Engineers consider several variables when designing piping systems to limit potential for water hammer. Whenever a major change is made to the distribution or collection system, implications for water hammer should be evaluated.

This week’s featured video demonstrates how water hammer occurs and what it looks like using 100 feet of clear PVC pipe with an analog and digital pressure gauge. The host explains how engineers can modify the potential for water hammer in piping systems by manipulating the variables that make up the mathematic equation for the pressure profile of a water hammer pulse. Such design parameters include pipe size, recommended operating procures for closing valves, and more. Watch the video to understand how the design considerations for your piping system impact water hammer.

Rural Water Representation in the 2020 Census

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As we approach the execution of the 2020 decennial census, rural communities and their water and wastewater facilities should be aware of the ramifications a new count will have on funding allocation in their community. The U.S. census is updated every 10 years in an effort to enumerate every living person in the United States. While it’s common knowledge that the count is used to update congressional district lines, the census is also used by many federal programs to determine funding distribution. Census data will help programs access population characteristics of communities, the allocation of funds to eligible recipients, and the success of ongoing programs.

In 2015 132 federal programs used census data to distribute over $675 billion in funding. Many of these programs targeted rural development, source water protection, emergency water assistance, and water and wastewater infrastructure.

The upcoming census will start April 1, 2020 by issuing every home on record with a mailed invitation to participate. Responses can be submitted online, over the phone, or by mail. The questions asked by the census cover information about property ownership, gender, age, race, and the number of people living in the residence. Responses are kept confidential under federal law. Census takers will also begin visiting colleges, senior centers, and large community living groups to conduct quality checks. By May 2020, the Census Bureau will visit the homes of those who have not submitted responses. To achieve an accurate count, the U.S. Census Bureau has worked to build an inclusive address list of housing units and develop methods to improve both self-response and follow-up procedures for those who do not respond.

While intensely rural and marginalized communities are historically more susceptible to undercounting than urban, the 2020 census design poses new concerns for rural areas. In an effort to reduce field costs and visits, the upcoming census strategy will be the first to encourage internet self-response. To address known areas of low internet connectivity, the Bureau will mail identified households a paper questionnaire or request responses over the phone. Areas with noncity-style addresses such as rural route numbers will receive a paper questionnaire from a census worker at their door. In the most remote areas, a census taker will enumerate households in-person. Unfortunately, two of the three ‘End-to-End’ tests to evaluate these methods were cancelled leaving insight into how rural communities will be effected by the census design poorly assessed.

The in-person visits pose significant challenges since the homes of remote areas are often spread apart, hidden from the main road, and made up of non-traditional living quarters. As a result, communities in rural Alaska and tribal lands are typically the most undercounted. Furthermore, minority groups, low-income individuals, and rural areas with slow internet connections will find response more difficult than those of urban areas.

Encouraging participation will ensure that your community receives a fair share of rural development and water infrastructure funding. Undercounts can impact anything from justifying water rights to determining eligibility of grants and loans. Public water and wastewater systems, especially those in Indian Country, should request that their local government promote census participation. To start this process, towns or tribal governments can become a Census Bureau partner to have access to promotional materials and census updates. Using local media, radio stations, social media, public meetings, and flyers, rural communities can host outreach campaigns that advocate the significance of the census and how to pro-actively participate. When possible, we encourage communities to make internet response publicly available at local churches, libraries, community centers, etc. With community planning and education, rural communities can be accurately represented in the 2020 census.

Featured Video: Wastewater Treatment Process Control Testing

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This week’s featured video was produced by the Athens Wastewater Treatment Plant. The plant serves a small town of approximately 1,050 people in West Virginia. In an effort to educate their small town and others across the country, Athens WWTP has developed a series of videos. In this particular recording, the plant will demonstrate several process control tests they use to evaluate their wastewater conditions. You’ll learn how Athens performs a settleometer test and monitors pH, temperature, dissolved oxygen, oxygen reduction potential, mixed liquor suspended solids, and volatile suspended solids.

Tests likes these are valuable for troubleshooting the dynamic environment of wastewater treatment processes and meeting regulatory compliance. As such, it’s important for sampling to be performed accurately, consistently, and in a location that is representative of the wastewater quality as a whole. The types of tests you perform, the number of samples taken, and the laboratory methods used to analyze these samples will depend on your system’s treatment type, chemical usage, equipment, and raw water quality. Results from the analysis will promote process optimization. A detailed copy of your facility’s sampling and testing procedures should be accessible in the utility Operations and Maintenance Manual for reference.

To provide more information on process monitoring, we’d also like to recommend:


Studying for the Certification Exam

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Studying for the certification exam can seem difficult or tedious for the many of us who are out of practice when it comes to taking and preparing for standardized tests. Adding to the challenge, most operators or operators in training must balance daily responsibilities and work with studying. In this week’s blog post, we hope to make your certification exam prep more productive by reviewing the best methods to study.

Before studying for the exam, operators should start by briefly researching the exam itself. Knowing the topics that will be covered and the resources that will be available during the test can help you make the best use of your study time. For starters, each certification agency can have a substantially different distribution of topics included on their need-to-know (NTK) criteria. The American Water Works Association (AWWA) published a 2018 summary of each state’s licensing requirements and NTK criteria (if developed), however operators should check with their primacy agency directly to really familiarize themselves with the test requirements, format, and design.

For most primacy agencies, certification exams are administered online at a certified testing center, however many agencies offer a few pencil and paper exams throughout the year. Operators that are taking an online exam can familiarize themselves with the feel of an online test using the Association of Boards of Certification’s (ABC) exam demo. For either exam format, the test taker should find out how many questions will be included in the exam, what the question format will be, and how many minutes they have to complete the exam. Certification agencies that use ABC testing services require candidates to bring photo ID, a non-programmable calculator, two sharpened #2 pencils, and an eraser. The exam will likely provide a Formula/Conversion table that you should practice with during your studies. Please check with your primacy agency to determine what score is required to pass. Most agencies require a 70% or higher.

The AWWA suggests that operators should begin studying immediately after submitting their testing application. Applications are generally due two to three months before the test date itself offering ample time to study. During this period, test takers should strive to learn and understand, not memorize, all the material identified on the NTK criteria. Setting a goal to study at the same times and location each day will help improve focus when you sit down to work. As you study, keep your notes and study material in the same binder or notebook to improve organization. How long you study each day will depend on your current knowledge and experience. Even if you think you know some material pretty well, set aside time to review just in case.

Deciding how to study and the resources you want to use will depend on how you learn best. Some operators retain information by reading and writing. For the exam, this might look like learning from a textbook or manual and then summarizing the information in flashcards or a study guide. Research has shown that writing down information improves retention. Generally by the time a student has finished their flashcards, they already know the material pretty well. Reviewing those written summaries will only reinforce that knowledge. Check out our previous blog post on free test prep resources to find downloadable study manuals. If you want to use a textbook instead, we recommend purchasing them used whenever possible!

Many other operators prefer a visual or auditory form of learning that comes from watching training videos online or enrolling in a certification exam prep course. If already studying from a textbook, we encourage visual learners to make their own diagrams and charts. Operators can find upcoming certification classes by visiting our national training calendar and selecting “Certification/Exam Prep” in the Category filter. Training courses are also good for kinesthetic learners that retain information by 'doing'. To really prepare for the exam, chances are high that you will need to apply a combination of these study methods. When none of these tips seem to work and you just can’t seem to remember an important fact or process, try developing your own mnemonic.

The last important tip we must offer is to repeat, repeat, repeat! In order to remember anything long-term, you should review the same material several times without cramming. For example, during the duration of your exam prep try reading from your study manual and summarizing the information in a notebook. Return to those summaries periodically, perhaps creating diagrams when possible or even rewriting the material for a second time. When you feel like you know your stuff, take a practice test to assess your knowledge.

Practice tests will help students determine where they need to improve while letting them get used to the types of questions that will be asked on the exam. Some primacy agencies have developed their own practice tests, however we recommended several additional practice exams in the October 29, 2019 edition of the WaterOperator.org Newsletter. The edition also includes some of our own practice questions and helpful test taking tips for the day of the exam.

Remember that doing well on the exam requires developing a study plan and sticking to it. With any luck, and a lot of practice, these tips will have you acing your certification exam!

Managing Hexavalent Chromium in California Small Drinking Water Systems

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Photo Credit: "PG&E Did It, And Always Knew, Since 1952!" by Alison Cassidy 05/31/2015; Edited with cropping and color correction.

In recent years, hexavalent chromium (chromium-6) has become a taxing contaminant for small water systems in California to manage. The contaminant has a complex regulatory and legal history, some of which was made renowned by the 2000 film Erin Brockovich starring Julia Roberts. Presently, an invalidated state drinking water standard, an uncertain regulatory future, and varying positions on the potential drinking water health risks, leave small systems unsure how to proceed. Chromium-6 challenges have only been exacerbated by its history of environmental contamination through industrial sources.

On a federal level, there is currently no drinking water standard. Hexavalent chromium was evaluated under the third round of Unregulated Contaminant Monitoring (UCMR 3). While the U.S. EPA is still evaluating the results and risks of chromium-6, there is no current undertaking to develop a new drinking water standard. A regulation does, however, exist for total chromium which includes all forms of chromium. The total chromium standard of 100 ppb assumes that the chromium sample is composed entirely of its most toxic form, chromium-6, to safeguard against the greatest potential risk. In California the total chromium standard was set at 50 ppb. At the time these total chromium standards were established, ingested hexavalent chromium was not associated with cancer risks. Exposure through drinking water has now been linked to both cancer and skin reactions.

According to a 2018 publication by the Water Research Foundation, the three most reliable water treatment technologies for chromium-6 removal include: reduction, coagulation, and filtration (RCF); adsorption onto regenerable strong base anion (SBA) resin; and adsorption onto disposable weak base anion (WBA) resin. Each technology generates unique waste with different handling and disposal requirements that can be expensive for very small systems to adopt and maintain. In a recent 2019 publication by the American Water Works Association, researchers identified a treatment technique that does not generate concentrated waste by reducing chromium-6 to easily separable and non-toxic chromium-3.

Much of the chromium found in drinking water was introduced from rocks, animals, plants, or volcanic activity. While both chromium-3 and chromium-6 can occur naturally, chromium-6 is more often affiliated with industrial sites that use chrome plating, paints and sprays, leather tanning, or corrosion inhibitors.

Hexavalent chromium was brought to the forefront of public health concerns in 1996 as a result of a class-action lawsuit between Hinkley, CA and Pacific Gas & Electric (PG&E). Prior to 1996 PG&E had released chromium tainted wastewater into unlined spreading ponds around Hinkley, a remote desert community in San Bernardino County. When Hinkley learned of the contamination years later, it filed a lawsuit against PG&E. During this time, legal clerk Erin Brockovich worked to link cancer illnesses to chromium-6 exposure. A convoluted series of legal battles between PG&E and those who developed illnesses from the contamination left the scientific community uncertain about the health risks of chromium-6 in water.

Only in 2008 did the U.S. EPA recognize research by the National Toxicology Program identifying cancerous tumors in rats and mice who ingested heavy doses of hexavalent chromium. By 2013 the growing plume of contamination in Hinkley had spread to over six miles long and two miles wide. Following a long regulatory investigation of the chromium-6 health effects during the PG&E legal battles, California eventually recognized the link between chromium-6 and cancer in 2014, approving a maximum contaminant level (MCL) in drinking water at 10 ppb effective July 1, 2014.

The new standard proved difficult for many small utilities to meet compliance. Senate Bill 385 gave systems with source water above the new MCL until January 1, 2020 to come into compliance without violations. During this time, impacted systems had to submit plans for achieving compliance, obtain approval of the plan, and carry out the plan in a timely manner. Plans could include steps for finding funding, conducting a feasibility study, investigating treatment options, performing an environmental review, acquiring land, facilitating construction, and testing. 

Developing, implementing, and submitting reports for these plans was no small task for any utility. Drinking water systems granted time to meet compliance were also monitoring sources of hexavalent chromium quarterly. As systems notified customers of new exceedances, they took on the burden of managing strong community concerns. It’s estimated that chromium-6 has been detected in 2,475 California drinking water sources spread across 48 out of 51 counties. The Environmental Working Group published a map that includes the average detected chromium-6 concentration by county across the country.

In developing the new MCL, California estimated that costs to implement the rule would increase water bills by $64 per year for customers of large systems and $5,640 per year for customers of small systems. Polluters were not held accountable to assist with compliance costs in areas of industrial contamination. For small drinking water facilities like the Phelan Pinon Hills Community Services District (PPHCSD) or the San Bernadino County Special Districts Department, the sticker price for compliance came at a cost in the millions. Furthermore, these small systems must spread costs over fewer people making the adoption of hexavalent chromium solutions cost prohibitive. In San Bernadino County, PPHCSD opted to take on a water blending project while the San Bernadio County Special Districts began exploring a pilot program for new treatment technology. Ultimately petitioners against the rule claimed that the MCL was too stringent with compliance too expensive. As a result, the rule was invalidated in 2017 by Sacramento Superior Court under grounds that the Department of Health failed to consider the economic feasibility for small water systems. By this time towns like Phelan had already spent $3.7 million toward the mitigation of chromium-6.

Using the data collected during the standard’s three years of implementation, the State Water Resources Control Board intends to develop a new MCL. As regulatory development ensues, impacted systems are left uncertain how to proceed. There is no certainty that a new MCL will in fact be implemented. Yet if the Board successfully passes a new MCL, systems cannot be certain that the standard will remain at 10 ppb. The board developed this FAQ sheet to help systems with ongoing loans and project plans determine their next steps. The PPHCSD in Phelan believes that the 10 ppb standard will be reinstated and has continued to move forward with their $17 million blending project.

Systems that choose to pause or discontinue projects are still left uncertain whether they are providing their community with safe drinking water. While legally facilities must now comply with the total chromium standard of 50 ppb, California did set the chromium-6 public health goal (PHG) at 2 ppb. This PHG conflicts with the U.S. EPA’s total chromium maximum contaminant level goal (MCLG) of 100 ppb and existing research debating that ingestion of chromium-6 can alter its toxicity. For now systems must use their best judgement and remain transparent with their community about all decisions. If the 10 ppb standard is reinstated, operators of nearly 800 groundwater supply wells will be in violation of the rule according to a 2018 publication by Hausladen.

California small water systems are not alone in their challenge to manage drinking water contaminants in the absence of strong regulatory guidance. Water systems across the country have had to make tough decisions about treating unregulated drinking water contaminants, many of which were spread through commercial practices. An example of such contaminants is per- and poly-fluoroalkyl substances (PFAS) and cyanotoxins. Utility decision making to handle these unregulated contaminants must factor in finances, source water conditions, potential project affordability, availability for partnerships, existing infrastructure needs, and more. As we move closer to the new year, water systems and regulatory agencies should take note of the chromium-6 decision-making in California to understand the potential impacts of new regulations on small systems.

Katie Buckley substantially contributed to this article.

Collaborating Effectively with Board Members

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To protect public health and maintain reliable services, operators and board members, or other governing bodies, must collaborate effectively. This collaboration is essential to successfully establish and execute short-term and long-term system goals. In this blog post, we will discuss how to improve collaboration between board members and operators by distinguishing responsibilities between the two groups and providing communication tips for operators.

RESPONSIBILITIES

To work effectively in any team, each member must understand their own responsibilities and how those responsibilities are distinguished from the responsibilities of others. The primary role of board members is to ensure the system provides reliable and compliant services by setting policies and goals, maintaining finances, and communicating important utility information to customers. Their responsibilities include:

Management: Board members are in charge of hiring, retaining, and contracting qualified workers. They must set policies (pg. 9) and goals that allow the utility to operate efficiently and legally. Evaluating these goals regularly will ensure that the system can maintain a desired level of service, protect source water, apply appropriate asset management programs, and keep customers informed. Boards should operate ethically and make sure records are retained properly. To do all of this, each board member should facilitate active participation in decision making while acting as a good team member for the utility. They must also acquire the required knowledge to fulfill these duties.

Financing: Decision makers must maintain budgets, monitor spending, and ensure that the system will have enough money to meet both present and future needs. When necessary, boards are in charge of acquiring the funds to finance infrastructure projects and other activities required by the system. Any major contracts must also be approved and properly recorded by the board.

Communication: Board members must keep customers informed on ongoing projects, system services, and potential emergencies. They should act as the liaison between the system's staff and the community. Additional responsibilities include maintaining transparent communication to the public through open meetings that have been scheduled with appropriate public notice and an organized agenda. By publishing meeting minutes and key decisions, customers can remain informed and provide additional input.

After board members have established the financial and managerial policies for the system, it is the operator’s responsibility to implement and enforce those policies. Operators must develop, update, and execute maintenance plans and standard operating procedures (SOPs) that meet board policies and regulatory compliance. These procedures will help staff facilitate daily operations, monitor the system, and maintain detailed records of the system’s status as well as any financial expenditures. Operators must also maintain, monitor, and replace existing assets. While both operators and board members should possess a sufficient education to manage the facility, operators must do so by upholding their certification license. In addition to these tasks, it’s important for operators to keep board members informed of system updates and needs.

COMMUNICATION

To effectively collaborate and communicate as a team, board members and operators should attend regularly scheduled meetings. The Nevada Bureau of Health Protection Services recommends board members schedule these meetings on the same day once every month. During meetings customers can discuss concerns with board members, board member can inform customers of changes to the system, and operators can provide updates to their board. Successful meetings should always be conducted to comply with the region’s Open Meeting Laws and to follow a pre-written, detailed agenda.

Before any meeting the board’s secretary should collaborate with operators and other board members to produce a clearly written agenda that will include discussion topics, action items, and time for public comment. This is the time where operators can schedule to bring forth concerns, needs, and system updates. The Environmental Finance Center hosted an excellent webinar in 2016 on successful communication with board members. The webinar describes what topics and details are important to discuss at meetings and what are not. The webinar also demonstrates how policies are made and updated during these meetings. The following figure was taken from this webinar:

Board and Staff Relationship

When an operators bring up concerns, requests for funding, or updates on the system, they should do so with the following strategies:

Presenting the Update or Issue:

Proposing Solutions to Challenges:

  • Provide reasonable options to resolve system issues and clearly explain the risks involved in not taking action. Describe how the proposed solution will resolve the issue.
  • When the solution involves replacing new equipment, explain estimated life cycle costs in addition to upfront costs. Identify where the funding to finance the solution will come from and where that will leave the system financially afterword.
  • Understand how proposed solutions and projects will affect other funding needs in the community. Explain how the solution will benefit the community as a whole.
  • Offer the board a non-technical explanation of why the proposed solution is required so they can relay this information to customers.

Other Tips:

  • When operators don't know the answer to questions from the board, it’s best to offer to investigate the answer later rather than guess. Waiting to provide an accurate answer limits confusion and unnecessary conflict.
  • Board members are often unfamiliar with the daily operations of the utility. It can help improve collaboration to offer tours of the facility that demonstrate operating requirements and updated conditions of the plant. Alternatively, operators can invite board members to attend training classes and conferences. The Rural Community Assistance Partnership (RCAP) also offers water and wastewater guides for the non-operator that can act as a starting point for this technical knowledge.
  • Keep the lines of communication open. When board members can communicate their opinions openly it will lead to reciprocation and more effective problem solving.
  • Compromise!

When collaboration becomes difficult, remember that both operators and boards have the same goal: protecting public health and ensuring the longevity of the system. While board members can face different pressures than operators, they still want to maintain this goal. Elizabeth Dietzmann with the Kansas Rural Water Association has written two excellent articles for operators on How to Manage a Micromanaging Board and How to Manage a Problem Rural Water Board Member. The latter addresses “No Show” members, “Blabbermouths”, the “Angry Bird”, and other problem members.

Remember that communication doesn’t have to be limited to monthly meetings. Operators can provide weekly email updates or use phone calls to inform boards of important issues. For additional resources on board responsibilities check out RCAP’s Big Guide for Small Systems: A Resource for Board Members. As operators maintain their own continuing education requirements, they can also encourage board members to attend any upcoming RCAP board training that will help them brush up on their job duties and stay up to date on the industry.

Peracetic Acid (PAA) in Wastewater Disinfection

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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

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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.