Free Compliance Resources for DBPs

Our 2020 free webinar series highlighted compliance-related resources on a number of topics. This recording contains information and free resources on DBPs. Listed below are all the resources mentioned in the video.

Comprehensive Disinfectants and Disinfection Byproducts Rules (Stage 1 and Stage 2): Quick Reference Guide
The 4-page fact sheet overviews both the Stage 1 and Stage 2 Disinfection Byproducts Rules. Operators will learn about each rule's requirements including monitoring requirements, MCLs, MCLGs, compliance determination, and the contaminants included under each rule.

Stage 1 Disinfectants and Disinfection Byproducts Rule
This four-page fact sheet provides detailed information on Stage 1 of the Disinfection Byproducts Rule and its history. 

Fact Sheet: Stage 2 Disinfectants and Disinfection Byproducts Rule
This is a four-page fact sheet that uses questions and answers format to help water systems understand what stage 2 of the Disinfection Byproducts Rule entails. 

Regulating Disinfectants and Disinfection Byproducts 
This 2-page fact sheet created by the Washington State Department of Health is geared towards new water operators that are interested in learning more about Disinfection Byproducts Rule. 

Initial Distribution System Evaluation Guidance Manual For The Final Stage 2 Disinfectants and Disinfection Byproducts Rule
This is a 434- page manual from the U.S. EPA that covers various components of an initial distribution system evaluation. 

Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR) Compliance Monitoring Plan Template For Public Water Supply Systems
This is an 11- page template with information from the U.S. EPA on public water supply systems and operations instructions on selecting appropriate monitoring sites for TTHM and HAA5. 

North Carolina DEQ Disinfectants and Disinfection Byproducts Rule Template 
This website page from the North Carolina DEQ includes a 15-page template and an 8-page instruction manual with information on how to monitor for TOC, chlorine dioxide, chlorite, bromate, and DBP precursors. 

Monitoring Plan for the Disinfectants/ Disinfection Byproducts Rules
This 27-page template and 10-page instruction manual from the Pennsylvania DEP includes a monitoring plan as reference. 

Stage 2- Disinfection Byproducts Monitoring Chart
This is a one-page fact sheet from the North Carolina Department of Environmental Quality that lists monitoring requirements for disinfection byproducts. 

Disinfectants / Disinfection Byproducts (DBP) Rules Monitoring & Reporting Requirements For Public Water Systems
This 16-page factsheet from the Pennsylvania Department of Environmental Protection provides monitoring requirements for DBPs, disinfection residuals, and TOC. 

Sample Collector's Handbook Stage 2 Disinfectants and Disinfection Byproducts Rule
This 21-page handbook from the Illinois Environmental Protection Agency outlines monitoring requirements, reduced/ increased monitoring, determining MCL compliance, performing and OEL, and sample collection tips. 

Sampling Procedures for TTHM and HAA5
This 14-minute video from the North Dakota Department of Environmental Quality lists components of a sampling kit, proper techniques and considerations when collecting TTHM and HAA5 samples, and chlorine residual sampling as well. 

How To Collect A Drinking Water Total Trihalomethanes (TTHM) Sample
This is a 3-minute video on proper TTHM sample collection following EPA Method 524.3.

How To Collect A Drinking Water Haloacetic Acid (HAA5) Sample
This is a 2-minute video on proper HAA5 sample collection following EPA Method 552.2.

Stage 2 Disinfectants and Disinfection Byproducts Rule Operational Evaluation Guidance Manual
This is a 180-page guidance manual from the U.S. EPA on requirements for operational evaluations, guidance for documents and reporting forms for OEL exceedance, and guidance on minimizing future OEL exceedances.

Water Quality Assessment Software (WQAS)
This is an excel sheet from the Department of Environmental Quality that can help water systems track DBP data (TTHM, HAA5), parameters affecting DBP formation (Water chemistry), and system-specific parameters. 

Regulating Disinfectants and Disinfection Byproducts
This 2-page fact sheet from the Washington Department of Health includes a table of disinfectants as well as advantages and disadvantages for each disinfectant. 

Recommended Treatment Techniques for Controlling Disinfection By-Products
This is a 20- page guidance document from Florida Rural Water Association on treatment techniques for small to medium-sized water systems. 

Disinfection By-Products Troubleshooting Guide
This is a 4-page factsheet from the Florida Rural Water Association on troubleshooting process changes in water treatment, distribution system, and source water changes.

Public Notification Templates for Community and Non-transient Non-community Water Systems
This website provides a list of public notification templates to assist primacy agencies with implementing the Public Notification Rule.

Complying With the Stage 1 Disinfectants and Disinfection Byproducts Rule: Basic Guide
This 50-page guidance manual from the U.S. EPA provides information about the health risks associated with DBPs, monitoring requirements of the Stage 1 DBPR, how to determine if systems are in compliance, how to maintain compliance, reporting requirements, and how the Stage 1 DBPR compliance can affect other rules.

Complying with the Stage 2 Disinfectants and Disinfection Byproducts Rule: Small Entity Compliance Guide 
This 57-page guidance manual from the U.S. EPA provides information on Stage 2 DBPR requirements, compliance monitoring requirements, how to select monitoring sites, operational evaluation, locating and fixing problems, financial assistance information, and public notice requirements.

Simultaneous Compliance Guidance Manual for the Long Term 2 and Stage 2 DBP Rules
This 462-page manual from the U.S. EPA provides information on how to identify and mitigate issues that systems will face when implementing changes necessary to comply with the Stage 2 DBPR and LT2ESWTR while still being required to comply with other SDWA regulations.

Stage 2 Disinfectants and Disinfection Byproducts Rule Consecutive Systems Guidance Manual 
This 73-page guidance manual from the U.S. EPA provides information on stage 2 DBPR requirements for consecutive systems, compliance options for consecutive systems, communication strategies between consecutive and wholesale systems to improve water quality from wholesale systems, and developing consecutive system compliance strategies to meet the stage 2 monitoring requirements.

EPA Small Systems Monthly Webinar Series Disinfection Byproducts (DBPs): Regulatory Issues and Solutions
This 54-minute webinar provides a review of the Stage 2 DBPR monitoring and reporting requirements and of small system DBP challenges in the State of Washington while highlighting a few success stories.

EPA Small Systems Monthly Webinar Series Stage 2 Disinfection Byproducts Rule and Simultaneous Compliance Webinar
This 70-minute webinar provides a review of the Stage 2 DBPR and EPA’s 2018 In-Depth Analysis and of challenges water systems face during simultaneous compliance between the Stage 2 DBPR and other NPDWRs.

Stage 2 Disinfectants and Disinfection Byproducts Rule (DBPR) and Consecutive System In-Depth Analysis
This is a 35-page report from the U.S. EPA on approaches to optimize systems and reduce DBPs through EPA’s Area-Wide Optimization Programs (AWOP).

Reducing Disinfection Byproducts through Optimization Webinar Series
This is a 4 part webinar series from ASDWA that shares optimization-based tools and approaches for DBP control from various states.

Please note that we are not able to provide certificates for watching a webinar recording.

Opinion: Challenges Quantifying COVID-19 Cases Using Wastewater

Editor's Note: The views expressed in this post are the sole opinion of the author and not those of WaterOperator.org, our sponsors, or the University of Illinois.

In the May 5, 2020 edition of the WaterOperator.org newsletter, we highlighted ongoing research that uses wastewater-based epidemiology to monitor the spread of SARS-CoV-2, the virus that causes COVID-19. Especially in locations where no confirmed cases have been identified, any samples positive for SARS-CoV-2 viral RNA implies that there are people infected in that community excreting it. For that purpose, wastewater monitoring shows real promise as an approach to early detection. By monitoring wastewater influent, scientists hope we can develop an advanced warning system for outbreaks.

There has been significant buzz about using wastewater to quantify the actual number of people infected within a given service area, but there are some issues with quantifying cases I want to discuss. In our newsletter we highlighted MIT research aiming to quantify the number of infected from a large area in Massachusetts. In that article, the researchers point to concerns about meeting the litmus test of sound science.

The wastewater system they studied had 450 confirmed cases at the time of sampling. Results from this monitoring suggested the number of people infected could be much higher. They estimated somewhere between 2,300 and 115,000 infected people. A range this wide does little to help planners or health officials prepare for what might be coming during a pandemic.

Quantifying the number of people infected with COVID-19 using wastewater samples requires a much more comprehensive data set that we cannot gather today in any cost effective way. Here are a few of the problems I see in quantifying the positive COVID-19 population within a given wastewater system:

• Not everyone excretes the viral RNA:
  A recent study published March 30 in the American Journal of Gastroenterology found that some COVID-19 patients exhibit gastrointestinal symptoms, with those patients more likely to produce a positive stool test. In other words, COVID-19 positive patients may not have ANY viral RNA in their stool. How do we identify those people?
• Wastewater varies throughout the day and throughout the week:
  The influent coming through a plant varies based on the discharges from the users. A lot of variables can affect wastewater characteristics at the specific time a sample is collected. The time of day, time of week, and even the time of year can affect the flow into a plant depending on the types of users in the system.
• Every system has a variety of sources for their wastewater:
  What percentage of the wastewater is residential? Are there commercial or industrial facilities that are discharging to the community system? If so, how much, and what types of businesses? In some communities, commercial and industrial users could make up a significant portion of the wastewater treated. In a rural area, the regional hospital may be in a smaller community making it a significant source and contributor. Other communities could be almost completely residential.
• Sampling time and frequency can skew the results:
  Sampling time matters, as do the number of samples collected. How do we decide what is representative? Once an hour? Once a day? Sampling may need to be continuous to really understand the variability.
• Wastewater collection systems leak:
  Leaking can occur both ways. Some wastewater leaks into the environment through the collection system while, at other times, a high groundwater table may be leaking groundwater into the collection system. I looked at approximately 50 smaller systems in Illinois to compare the amount of wastewater discharge to the amount of groundwater they withdraw from drinking water wells. (You would expect the amount withdrawn from wells to be more than that treated at the wastewater plant because of consumptive use.) In many cases systems were treating more wastewater than the raw water being used for their community supply and, in some cases, it was 2-3 times a much. This would be significant factor when using any volumetric approach to evaluating COVID-19 sampling results.
• We have no benchmark to compare results:
  Without having data for a number of communities where the total number of residents with active COVID-19 infection is known, there is no way to validate assumptions and calibrate estimates built into the method. This would not be possible without a consensus understanding about the rate of asymptomatic cases.

If researchers must accept such a high degree of uncertainty, how can this method ever be accurate or useful? Many factors would have to be considered to quantify the number of positive cases for a given community and these would be unique to the individual system. That said, these are not likely new considerations for the talented researchers working on this effort. 

In the future I hope an approach to accurately quantify an infected population using wastewater-based epidemiology becomes a reality. It would be a tremendous asset. In the meantime, however, I believe our focus should be on evaluating the pitfalls mentioned above and working toward technologies/protocols needed within a wastewater plant to reduce uncertainty and move us closer to our common goal of protecting public health.

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.

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.

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.