Challenges Developing an Asset Management Program

Developing and maintaining an asset management program benefits the short and long-term operations of any utility. During operational, financial, and managerial decision making, choices can be backed by quantifiable data and knowledge gathered from asset inventories, condition assessments, and risk assessments. Furthermore, the maps, spreadsheets, and reports generated for asset management programs can improve communication between board members and utility staff. Asset management programs allow utilities to shift their operations to preventative maintenance and long-term planning.

The recommended methods to develop asset management programs are well documented, however implementation of such methods in the real world generates a slew of both predictable and unpredictable challenges. Fortunately for all communities, it is the responsibility and the nature of any utility to problem solve and overcome these challenges.

In October of 2017, the Michigan Water Environment Association (MWEA) and the Michigan Section American Water Works Association (MI-AWWA) hosted a roundtable seminar on asset management plan development. The results of this roundtable highlight how communities and their consultants developed their own plans in response to new regulatory requirements in Michigan. The Spring 2018 Edition of MWEA Matters summarizes the actual approaches undertaken by these facilities and how they overcame individual challenges in developing an asset management program. These approaches and challenges were divided into six categories:  inventory, condition assessment, risk, O&M/ capital planning, rate integration & level of service, and software.

Most challenges in asset inventories arose around the question of how and where to organize data so that information could be related to other data sources. Challenges in condition assessment were often rooted in cost limitations, evaluating underground infrastructure, and weighting the data available from equipment history, maintenance history, age, condition scores, visual inspections, engineering judgement, and operational institutional knowledge. During risk assessment difficulties emerge when estimating risk for uninspected equipment or considering system redundancies. The final challenge lies in determining how to make maintenance program and financial decisions by balancing institutional knowledge with system modeling.

Utilities can find expertise in avoiding or overcoming these common program develop challenges through the Rural Community Assistance Partnership (RCAP) or the National Rural Water Association (NRWA). We also recommend searching through our online resource library to find program develop manuals, spreadsheets, and tips to get started. For a general overview of the program development process, review the 13 Session Asset Management Training Slides by the U.S. Environmental Protection Agency.

RCAP Advocacy and Policy Update: COVID-19 Response

Over the last two weeks, the National Office has been active in promoting the needs of rural water systems and small communities during this ongoing COVID-19 crisis. In the last two weeks, Congress has approved and President Trump signed into law Phase 1 (H.R. 6074) and Phase 2 (H.R. 6201) legislation addressing the COVID-19 crisis in a variety of ways. Phases I, II, and III are the three parts to COVID-19 legislation so far. 
 
Phase I, enacted into law March 6. Provides $8.3 billion in emergency funding for federal agencies to ensure vaccines developed to fight the coronavirus are affordable, that impacted small businesses can qualify for Small Business Administration (SBA) Economic Injury Disaster Loans (EIDLs), and that Medicare recipients can consult with their providers by telephone or teleconference, if necessary or desired.
 
Phase II, signed into law on March 18. This package includes provisions for paid sick leave, free coronavirus testing, expanded food assistance, additional unemployment benefits, and requirements that employers provide additional protection for healthcare workers. 
 
Phase III, signed into law on March 27. The Trump administration struck a deal with Senate Democrats and Republicans on a package providing an estimated $2 trillion in spending and tax breaks to strengthen the U.S. economy and fund a nationwide effort to curtail the coronavirus. The price tag of this package is enormous, unprecedented, and is roughly equal to 10% of the country’s economic output. The plan includes approximately $500 billion that can be used to back loans to distressed companies, including $50 billion for loans to U.S. airlines, as well as state and local governments. It also contains more than $350 billion to aid small businesses. While stipulating the airlines as eligible for a special fund of money available for loans, the legislation is otherwise broad in its approach, recognizing that the coronavirus has affected almost every sector of the economy. 
 
It provides payment to states to reimburse nonprofits, government agencies, and Indian tribes for half of the costs they incur through December 31, 2020 to pay unemployment benefits; and funding to support “short-time compensation” programs, where employers reduce employee hours instead of laying off workers. Employees with reduced hours receive a pro-rated unemployment benefit. This provision would pay 100 percent of the costs they incur in providing this short-time compensation through December 31, 2020.
 
Under Phase Ill, all U.S. residents with adjusted gross income up to $75,000 ($150,000 for married couples) would get a $1,200 ($2,400 for couples) "rebate" payment. They are also eligible for an additional $500 per child. The payments would start phasing out for earners above those income thresholds and would not go to single filers earning more than $99,000; head-of-household filers with one child, more than $146,500; and more than $198,000 for joint filers with no children.

Thank you to Ted Stiger, Senior Director of Government Relations and Policy at the Rural Community Assistance Partnership for providing this update on enacted legislation related to the pandemic.

WaterOperator.org Recommends Agencies Postpone Operator Certification Renewals During COVID-19

As communities tackle the COVID-19 pandemic, the critical services that water and wastewater utilities supply are ultimately pulled into the spotlight. While reliable drinking water and wastewater services remain essential to public health, they also sustain adequate hygiene practices to prevent the spread of illness.

Central to the continuity of operations for every utility lies our water and wastewater operators. Under normal operating conditions, operators, especially those of small or rural systems, must juggle the challenges of aging infrastructure, regulatory compliance, customer communication, board collaboration, and regular operations and maintenance. During the pandemic these challenges can be exacerbated by handling COVID-19 customer concerns, cross training staff, updating contingency and emergency response plans, connecting with critical suppliers, acquiring backup equipment and parts, reaching out to neighbors or mutual aid groups, etc. Operators must take on this workload while sustaining personal health and safety.

As operators manage the ongoing challenges associated with the Novel Coronavirus and Stay-at-Home orders, we have observed that several certifying agencies are extending or postponing their deadlines for continuing education requirements and the recertification of licenses expiring during this pandemic. WaterOperator.org believes that the focus of our operators should remain on continuity of operations and customer outreach without having to manage renewal and recertification requirements at this time. Our concern for small system operators, especially those of rural communities, is that some do not have access to reliable internet. Internet access that may have previously been obtained through public libraries or recreational centers is no longer accessible as a result of community shutdowns leaving operators with no alternative locations to complete online training for certification renewal. Given the extent of these shutdowns, online trainings do not offer a reliable substitute for in-person training sessions at an equal opportunity to all operators.

Many agencies are already working to address the accessibility and burden of licensing renewal. Among the certification programs who have provided relief for operators, agencies in Montana, Oklahoma, Texas, and Wisconsin as well as the Inter Tribal Council of Arizona are working to suspend or extend the time period for licensing renewal and continuing education requirements. In Ontario, Canada an emergency order offers relief to utilities by allowing operators with recently expired licenses to continue work while temporarily allowing non-certified, but qualified individuals to perform operational duties if deemed necessary. Taking a different approach, the drinking water program in Kentucky is currently waiving late fees for renewals until August 31, 2020. While licenses can still expire, the Kentucky Operator Certification Program will consider this grace period when performing inspections or alternate staffing plans. At this time other agencies are actively considering similar measures to the examples we’ve highlighted.

Where these actions are not possible, we ask that agencies consider supplementing other educational resources to operators in need. The Ohio Environmental Protection Agency notes on their website that correspondence courses are available for operators to earn continuing education credit. They recommend reaching out to local training providers to find these courses and other training alternatives. The Inter Tribal Council of Arizona is also researching self-guided distance learning and the loaning of training books distributed via mail.

For some operators, achieving educational requirements and licensing renewal through the duration of the pandemic will create an added burden that may impact their ability to protect and serve the citizens of their communities. Other operators may be left unable to run their facility due to an expired license. We are grateful to the primacy agencies that have taken positive action to support their operators. WaterOperator.org believes that these measures will help utilities of all sizes to protect their communities.

Featured Video: Disinfection Byproducts in Tap Water: 5 Things To Know

The challenge of disinfection byproduct (DBP) control in drinking water lies in balancing the varying health risks of over 600 known DBPs with the benefits of microbial waterborne illnesses prevented via disinfection. While DBPs can originate from industrial sources, they generally form in water treatment systems when natural organic matter reacts with a disinfectant, usually chlorine-based. Ongoing studies have suggested that the toxicity for any given DBP can range from having no known health effects to exhibiting links between exposure and cancer, birth defects, or reproductive disorders. Disinfectant type and dose, residual chlorine, inorganic and organic precursor concentrations, pH, temperature, and water age can impact DBP formation.

The management of DBPs in drinking water is enforced through the Stage 1 and Stage 2 Disinfection Byproduct Rule (DBPR). Collectively, the rules set maximum contaminant levels (MCLs) for total trihalomethanes (TTHM), 5 haloacetic acids (HAA5), bromate, chlorite, chlorine/chloramines, chlorine dioxide, and DBP precursors.

According to a 2019 report by the U.S. Environmental Protection Agency (EPA), the Stage 2 DBPR invoked the largest number of community water system violations between 2017 and 2018, accounting for approximately 30% of all drinking water violations. Consecutive water systems, those with surface water sources, and systems serving populations of 501 to 10,000 people experienced violations more frequently. A greater compliance challenge is experienced by consecutive systems because they have little control over the water that they receive. While treated water may have achieved compliance at the system’s interconnection, DBP concentrations can rise through the receiving distribution system.

Non-consecutive utilities experiencing compliance challenges for the Stage 1 or 2 DBPR can start by troubleshooting the system using our previous blog post on The Disinfection By-Product Challenge. Consecutive systems should coordinate with their wholesale system following the approaches suggested in the 2019 report discussed above. The preferable methods of control often lie in prevention and optimization. As your system troubleshoots the cause of high DBP concentrations, keep the community informed on your efforts as well as some basic information on the health effects and sources of DBPs. Operators can find a general overview on DBP challenges in this week’s featured video. We recommend using this video to provide customers with answers to the following questions:

• What are disinfection byproducts?
• How are DBPs regulated?
• How do I know if my water has high levels of DBPs?
• How are people exposed to DBPs?
• How do I remove DBPs from my home’s water?
  
  

Controlling Legionella in Drinking Water Systems

Photo Credit: CDC Public Health Image Library ID #11148 by Janice Haney 2009; Edited with cropping.

The prevalence of Legionella bacteria in drinking water and distributions systems has gained notice over the past several years due to its increasing rate of infection in the United States. Inhalation or aspiration of small aerosolized Legionella bacteria from water can cause Pontiac fever and Legionnaires’ disease most frequently in sensitive or immunocompromised populations. Between 2000 and 2015, the National Notifiable Diseases Surveillance System (NNDSS) reports that the incident rate of Legionnaires’ disease in the U.S. increased from approximately 0.42 cases per 100,000 persons to 1.89 cases per 100,000 persons. According to the Ohio Department of Health, potential reasons for this change in rate might include increased monitoring and awareness, higher population susceptibility, climate change, water-saving fixtures, and/or aging infrastructure. As of 2019 Legionnaires’ disease is reported to afflict and kill more people in the U.S. than any other waterborne disease.

Existing research indicates that, though Legionella bacteria can be found in all parts of the water treatment system, they amplify best inside protozoan hosts and near the biofilm typically found within premise plumbing or drinking water systems. The resiliency of biofilm to disinfection acts as a protective barrier for Legionella while creating an environment abundant in nutrients. Protozoan hosts also offer defense against extreme temperatures and treatment technologies. A 1994 study by Kramer and Ford found that hundreds of Legionella bacteria can be contained within a single amoeba vesicle. L. pneumophila, the species responsible for most human infections, can also differentiate into various life cycle forms that alter susceptibility to water treatment. This symbiotic relationship with other microorganisms complicates Legionella disinfection.

Hot spots for growth include showerheads, faucets, plumbing systems, cooling towers, hot tubs, fountains, and distribution systems where water stagnation, insufficient disinfectant residual, warm temperatures (77-124°F), or excess nutrients foster biofilm formation. As a result, the most frequent outbreaks from Legionella have been documented in hotels and healthcare facilities. Management of outbreaks can start at the site of these impacted buildings as well as the treatment plant. Drinking water utilities can participate in prevention by understanding the conditions that favor propagation and the methods to control growth.

The U.S. EPA established a Maximum Contaminant Level Goal (MCLG) for Legionella at zero microorganisms. While this is not an enforceable limit, the Agency believes that if Giardia and other viruses are removed or inactivated as required under the Surface Water Treatment Rule, Legionella will also be controlled. Requirements to manage bacterial contamination under the Revised Total Coliform Rule and Ground Water Rule also contribute to Legionella management. Though some systems may routinely monitor for Legionella bacteria, testing methods can often yield both false positives and false negatives. Given the complications of environmental monitoring as well as the cost, management generally starts in response to outbreaks or sporadic cases.

Ongoing research has identified that potential drinking water treatment methods for Legionella include chlorination, copper-silver ionization, ultraviolet (UV) light, ozonation, and thermal disinfection. Among these technologies, chlorine, chlorine dioxide, chloramine, and ozone are the most widely used disinfectants. A combination of these techniques offers the most effective defense against recolonization and biofilm formation. To inactivate individual bacteria as well as those contained within biofilm, operators should also pay attention to the contact time and concentration of disinfectant used during treatment. Equally important to contact time is the maintenance of disinfectant residuals throughout distribution. The National Academy of Sciences’ Management of Legionella in Water Systems details the recommendations for proper disinfection using free chlorine, chlorine dioxide, monochloramine, and technologies more commonly used by building water systems.

To effectively manage Legionella in drinking water, utilities must also collaborate with impacted buildings. Facilities that have experienced outbreaks can develop their own management plan using the Center for Disease Control’s (CDC) Developing a Water Management Program to Reduce Legionella Growth & Spread in Buildings and the World Health Organization’s Legionella and the Prevention of Legionellosis. This literature, along with the CDC training on Legionella Water Management Programs and the other resources linked within this guide will ensure that your community members, especially those at greater risk to illness, are protected from Legionella.

A Look at Protozoa in Wastewater Treatment Systems

Wastewater treatment is fundamentally a biological process. When influent enters the microbial ecosystem of a treatment plant, nutrient removal is accomplished through the consumption of organic matter by microorganisms. The bulk of all nutrient removal is performed by bacteria, however protozoa and metazoa balance these bacterial populations and offer insight into wastewater conditions. Operators who understand the varying roles of wastewater microbes and the conditions that favor their growth can foster an ecosystem that promotes optimal treatment. In this week’s blog post we will review the niche protozoa fill in wastewater systems to enhance monitoring efforts and inform process control.

Roughly four percent of a wastewater system’s microbial ecosystem is made up of protozoa. Protozoa are single celled microbes both larger in size than bacteria and more complex. The most common types of wastewater protozoa include amoeba, flagellates, and ciliates. By consuming free bacteria and small, unsettled floc, protozoa enhance the clarity of the final effluent. Observing protozoa populations under a microscope can also alert operators of treatment conditions and sludge age.

Amoeba are predominant under a young sludge age because they require high nutrient levels or low competition to grow. Under shock loads of biochemical oxygen demand (BOD), high concentrations of particulate matter, toxic conditions, or low dissolved oxygen (DO), amoeba can also dominate. The latter two conditions generally trigger the amoeba to develop a protective gelatinous shell that gives them an advantage over other microbes. Furthermore, their slow movement reduces oxygen demand required for growth and reproduction.

Flagellates are typically present under a young sludge age as well. Since flagellates compete poorly with bacteria for the same soluble nutrients, their growth is favored at the younger sludge age before bacteria have had a chance to populate. As such, a wastewater sample relatively high in flagellates can indicate high soluble nutrient levels also known as a high food to mass (F:M) ratio.

Ciliates are favored under a healthy sludge age. While they do not consume organic matter, they do feed on bacteria making them excellent indicators of healthy floc formation and useful clarifying agents. Without ciliates, bacteria and algae populations can grow out of control in the wastewater microbial ecosystem. Among the three types of ciliates common to wastewater, each group has different conditions under which their populations are favored.

Swimming ciliates start to form as flagellates disappear. They may experience a spike in population when levels of free bacteria are abundant for predation. If too many free bacteria are present, the ciliate population surge can ultimately result in a cloudy effluent. Crawling ciliates dominate when those free bacterial populations begin to stick together forming floc through a secreted slime layer. This slime layer is produced when dissolved nutrients become limited. Since swimming ciliates cannot readily pick off bacteria within the floc, crawling ciliates begin to out-compete them. As they feed on bacteria, crawling ciliates can improve flock structure. A more mature sludge age with reduced BOD allows stalked ciliates to compete with crawling ciliates. Stalked ciliates anchor themselves to floc using the cilia surrounding their mouth structure to create currents that draw in bacteria. Once their food levels have diminished significantly more, stalked ciliates begin to branch into colonial units to acquire food more efficiently. If sludge continues to age, stentors and vaginocola protozoa grow in abundance.

For more information on wastewater protozoa and how to monitor them, we’d like to recommend the following documents. These resources and others like them can be found using our online, resource library.

Bacteria Protozoa – Toni Glymph
The guide overviews basic wastewater microscopy, slide preparation, sample collection, and the microbiology of activated sludge plants.

Wastewater Microbiology & Process Control - Wisconsin Wastewater Operator’s Association
Learn the about microscopes, slide preparation, and the microorganisms found during wastewater treatment.

Protozoan Count – Toni Glymph
This guide describes how to sample protozoa for observation under the microscope.

Developing Your Source Water Protection Program

Effectively safeguarding drinking water sources will ensure that your community has reliable access to affordable, potable water for generations to come. As such, utilities of all sizes should strive to develop and implement a source water protection program. Not only do these programs reduce the need to adopt costly advanced treatment processes, but their value extends environmentally, socially, and through public health as well. By maintaining water quality at the source, systems protect a fundamental barrier under the multiple barrier approach. Furthermore, a protection program has potential to not only maintain, but improve water quality.

Developing and enforcing a source water protection plan will act as a proactive defense against contamination introduced from various land uses such as agriculture, commercial facilities, landfills, mining, oil and gas operations, stormwater runoff, failing septic systems, and more. A plan can also act to mitigate impacts from climate changes such as drought or saltwater intrusion. To start a program, systems can break down the process into six steps:

1. Delineating your source water protection area
2. Inventory sources of potential contamination
3. Assess susceptibility of your system to these contaminants
4. Notify and engage the public about these contaminant threats
5. Develop and implement a protection plan to reduce, prevent, or eliminate threat
6. Develop contingency planning strategies if source water is compromised

Of course, some of these steps are easier said than done. To assist in your source water protection endeavors, we’ve highlighted several resources to get you started. If you expect challenges along the way, consider contacting your regional Rural Community Assistance Partnership (RCAP) partner for support.

Before developing a plan, review your source water protection area and any existing contaminant sources identified by your state’s Source Water Protection Assessment Program (SWAP). Under the 1996 Amendments to the Safe Drinking Water Act, state programs were required to identify the land area that could impact water quality at each public water system. In addition, each state program completed an inventory of potential contamination sources in that area, evaluated water quality susceptibility to that contamination source, and made these results publicly available under SWAP. States completed the source water assessments in 2002, but were not required to maintain updates. To locate the results of your assessment, start with the EPA’s Source Water Regional Contacts or contact your state’s source water protection program.

The methods in which source water protection areas were identified and evaluated depend on the state. Many states published resources on how they chose to carry out the SWAP as demonstrated in the Connecticut Department of Public Health’s SWAP document. For updated or more local source water delineations and contaminant source inventories, public water systems can reach out to local environmental consulting firms, federal agencies like the NRCS or USGS, state cooperative extensions, and local colleges. The EPA has also developed a How-To Manual to Update and Enhance Your Local Source Water Protection Assessments that describes why and how you should collect more data.

With the state SWAP results and the EPA’s How-To manual, utilities can complete the first three steps in developing a protection program. Making the public aware of these results will allow systems to start collaborating with local organizations on source water protection efforts. By engaging local stakeholders such as the town officials, environmental groups, watershed organizations, farmers, businesses, town’s conservation commission, county extension, non-profits, etc. systems will better understand any existing source water protection strategies, who is conducting them, and how the facility’s present and future strategies can collaborate with existing strategies.

Based on data gathered from the source water delineation, assessment, and susceptibility evaluation, utilities can work with local stakeholders to develop a protection and contingency plan. While protection plans are optional in many states, utilities should first check with their state’s source water protection program to determine if a plan is mandatory and, if so, what elements must be included. The ease of which a utility implements their protection plan will depend on source water location, contaminant threats, financial and technical resources, and the degree of community involvement. To develop the plan, public water systems will need to identify management strategies and the funding to facilitate the plan.

A strong source water protection plan will have clearly defined goals with a list measurable actions and those who are responsible for them. Most plans should also include a timeline to measure progress, requirements for water quality monitoring, and a plan to track the successful completion of measurable actions. The goals outlined in the plan will ultimately address the water quality risks identified in the assessment through land use controls, land acquisition, and education. The scope of the plan may range in focus from local, regional, or statewide involvement. Check out the 2019 Roswell Municipal Water System plan to view an example of a medium-sized system’s source water protection program. To help develop a plan of your own, we’d like to recommend the following:

Guides:

The Source Water Stewardship: A Guide to Protecting and Restoring Your Drinking Water
The Clean Water Fund
The handbook walks public water systems through the process of understanding an assessment, reaching out to stakeholders, and designing an action plan.

New Mexico Source Water and Wellhead Protection Toolkit
New Mexico Environment Department
This toolkit will help public water systems develop a source water protection program in six steps.>

Templates:

Drinking Water Source Protection Plan Template (Systems Serving <5,000 people)
Ohio Environmental Protection Agency
This template can be used by Ohio or other public water systems to outline a successful source water protection program. Instructions should be deleted from the Word document upon completion.

Source Water Protection Plan Template
Tennessee Association of Utility Districts
This Microsoft Word template can be used as a starting point for developing your source water protection plan.

Source Water/Wellhead Assessment & Protection Program Planning Guide
South Dakota Department of Environmental and Natural Resources
This 10-page guide describes the sections that should be included in a source water protection plan.

Notification Templates:

Wellhead Letter to Potential Contaminant Sites
Tennessee Association of Utility Districts
Use this letter template to request assistance and cooperation in implementing your source water protection program.

Wellhead Letter to County Mayor and Zoning Board
Tennessee Association of Utility Districts
This letter template can be used to request assistance and cooperation from the county mayor and zoning board in the development and implementation of a source water protection plan.

Developing an effective source water protection plan will take time and collaboration. For more resources on protection plans, check out our document library and use the category filter to filter by Source Water/Source Water Protection.

The Best YouTube Channels for Water & Wastewater Operators

Whether it’s to troubleshoot a treatment process, practice for a certification exam, or update your facility’s standard operating procedures, working as a small system water or wastewater operator means that you’re always learning something new to get the job done. Our mission at WaterOperator.org is to make sure you can easily find the best resources to manage and maintain your utility and reliably serve your community. A great way to bolster your knowledge at your own convenience is through training videos and webinar recordings. In this week’s blog post, we’d like to highlight our favorite YouTube channels so you can reference them when you need to develop a new skill, practice for a certification exam, or simply learn more about how to manage your system.

Certification:

American Water College
The American Water College features a variety of water and wastewater training videos that teach operators about operator math, treatment processes, operation and maintenance best practices, and utility management.

CAwastewater
This YouTube channel includes several wastewater math training videos for Grade 1 to Grade 5 operators of California.

Wastewater Dan
The training videos by Wastewater Dan teach operators how to calculate anything from annual energy costs to chemical oxygen demand (COD).

TheWaterSifu
Training videos on TheWaterSifu demonstrate water treatment math, laboratory techniques, and skills useful for the water treatment or distribution exam.

Treatment, Operations, and Maintenance:

Aquafix, Inc
The Aquafix YouTube channel hosts webinar recordings on wastewater treatment and process control. Please note that some of these videos may include promotions for Aquafix products.

Lagoons Do It Better
Wastewater operators can find webinar recordings on lagoon treatment and troubleshooting. The channel also features interviews with industry professionals. Please note that some of these videos may include promotional material for industry products.

R.C. Worst & Co., Inc.
On this YouTube channel, operators can learn about the selection and maintenance of valves, joints, switches, pumps, motors, and tanks involved in onsite wastewater treatment systems, packaged pumping systems, drinking water wells, and water treatment. Please note that some of these videos may include promotional material for industry products.

RCAP (Try their Vimeo and their YouTube channels.)
Both RCAP’s Vimeo and Youtube channels feature training videos and webinar recordings pertaining to water and wastewater treatment, operations and maintenance, monitoring, and utility management.

Wastewater Operations Channel
On this YouTube channel, Wastewater Operator Jon Kercher uploads educational videos filmed during the workday at his wastewater treatment facility. Videos range from troubleshooting treatment processes to learning about biosolids.

The Water Research Foundation
The Water Research Foundation includes webinar recordings of utility case studies, water research, and innovative technology.

Waterworks Training
Operators can watch brief training videos that demonstrate the installation and use of pipe fittings, restrainers, saddles, and couplings.

Utility Management:

Environmental Finance Center at UNC-Chapel Hill
This YouTube channel includes training videos and webinar recordings to teach systems how to improve their financial, technical, and managerial practices.

Smart Management for Small Water Systems
Small systems can use these webinar recordings to improve or develop asset management plans, start a capital improvement project, or better understand utility finances.

WaterOperator.org also maintains a YouTube channel of our own so you can find previously recorded webinars, interviews, and playlists that highlight our favorite videos. Check out the playlist Free Webinars for Water/ Wastewater Utilities to find other useful webinar recordings by organizations like the Association of State Drinking Water Administrators and the U.S. Environmental Protection Agency.

Featured Video: Interviewing Basics Webinar

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

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.