ADVANCES WATER October–December 2020 | vol.30 no.4 in RESEARCH A Publication of The Water Research Foundation microorganisms also in this issue Responding to the Pandemic Biofiltration Microbiome Study Natural Assets VIEWPOINT Innovation W ater utilities face a wide array of challenges, including a growing number of regulatory requirements, deteriorating infrastructure, climate uncertainty, an aging workforce, affordability challenges, and much more. The water sector is seeking innovative ways to address these pressures, and many utilities are working to stimulate the development of novel ideas and partnerships. These utilities recognize that in order to thrive, the water sector must develop a culture that supports creativity and manages ideas as valuable resources. The Water Research Foundation (WRF) strives to foster this culture within the water sector, and to create an environment that helps innovative ideas flourish. Innovation is woven throughout all we do, including our research programs; collaborative technology evaluation trials; demonstrations of innovative technologies; and the Leaders Innovation Forum for Technology (LIFT), an initiative we share with the Water Environment Federation. Innovative approaches are not just about new and creative practices, but also about the people behind them. With that in mind, Advances in Water Research now includes a section dedicated to WRF’s innovative scientific and technical advancements, people, and stories. In this issue, Houston Water, under the leadership of WRF board member Yvonne Forrest, shares its involvement in the Scholarship Exchange Experience for Innovation & Technology (SEE IT), which provides utilities with opportunities to see innovative technologies and practices first-hand before adopting these technologies themselves. Innovation within the water sector is increasingly important as the challenges that communities face become more complex. The water sector cannot address the needs of the future by doing things the way we’ve done them in the past; we must explore new and unique approaches in order to succeed. WRF is your trusted source for water research and innovation, and we look forward to working with you to identify and pursue key opportunities that will further enable the sector to meet the needs of the communities we serve. Dennis W. Doll Peter Grevatt, PhD Chair, Board of Directors Chief Executive Officer ii October–December 2020 • Advances in Water Research CONTENTS VOL. 30 NO. 4 ii | Viewpoint: Innovation 2| 4| 7| By the Numbers: Biofiltration The Water Research Foundation (WRF) is the leading research organization advancing the science of all water to meet the evolving needs of its subscribers and the water sector. WRF is a nonprofit, educational organization that funds, manages, and publishes research on the technology, operation, and management of drinking water, wastewater, reuse, and stormwater systems—all in pursuit of ensuring water quality and improving water services to the public. Q&A: Interview with WRF’s 2020 Outstanding Subscriber Award Winners Advances in Water Research Statement of Ownership, Management, and Circulation Owned by The Water Research Foundation, 6666 West Quincy Avenue, Denver, CO 80235. Publisher: The Water Research Foundation; Editor: Alyse Greenberg; Bondholders: None; Circulation: Average number of copies distributed per month for 12-month period (October 2019 – September 2020) – 8513 as follows: paid and/or requested mail subscribers – 8413; free distribution – 100. This statement has been filed on PS form 3526 with the USPS on 11/17/20 and is published herein in accord with USPS regulation 39 USC 3685. Responding to the Pandemic 11 | Intelligent Water Networks 12 | Innovation in Action: Q&A with Aisha Niang Editor: Alyse Greenberg P 303.347.6116 • [email protected] Copyeditor: Barbara Swartz Art director: Cheri Good Customer service P 888.844.5082 or 303.347.6100 [email protected] 14 | 24 | 25 | 29 | Biofiltration: 30 Years of Research and Guidance Modeling Collection System Greenhouse Gases Management of Natural Assets Trace Organic Compounds Advances in Water Research • October–December 2020 20 | 24 | 28 | 29 | Chicago Area Waterway System Microbiome Study Transportation Biofuel Development Manganese Control Lead Service Line Identification Advances in Water Research (ISSN 1055-9140) is published quarterly for $100 a year in North America by The Water Research Foundation, 6666 W. Quincy Ave., Denver, CO 80235-3098 Telephone: 303.347.6100 Periodicals postage paid at Denver, CO. Postmaster: Send address changes to Advances in Water Research, The Water Research Foundation, 6666 W. Quincy Ave., Denver, CO 80235-3098 Copyright © 2020 The Water Research Foundation. ALL RIGHTS RESERVED. No part of this publication may be copied, reproduced, or otherwise utilized without permission. Published in the U.S.A. Printed on recycled paper. BY THE NUMBERS This installment of By the Numbers provides statistics on biofiltration and its use in drinking water treatment. For more information on this subject, see the article, Biofiltration: 30 Years of Research and Guidance. Biofiltration is the process of allowing microorganisms to colonize water treatment filters in order to remove biodegradable compounds from water. There are many drivers for, and benefits of, implementing biofiltration. Drivers for biofiltration identified by utilities participating in North American Biofiltration Knowledge Base Biofiltration can effectively reduce levels of various constituents, including total organic carbon, manganese, iron, ammonia, and geosmin. The ability of biofilters to remove contaminants is specific to the facility and target contaminant Total Removal Potential Contaminant Class Typical Contaminant Parameter Biofiltration Only Biofiltration with Pre-ozonation Removal Rates High (with appropriate High (with appropriate Data not available particle conditioning) particle conditioning) Particles, Pathogens Turbidity Oxidation Byproducts Assimilable organic carbon (AOC), Biodegradable dissolved Moderate to High organic carbon (BDOC), Carboxylic acids, Aldehydes, Ketones Disinfection Byproduct (DBP) Precursors (Natural Organic Matter) High* AOC: up to 220 µg-C/L Trihalomethanes, Haloacetic acids, N-nitrosodimethylamine, Low to Moderate Total organic carbon (TOC) Moderate TOC: 10–20% DBP formation potential: 20–50% Algal Metabolites 2-methylisoborneol (MIB), Geosmin, Cyanotoxins Moderate to High High MIB/geosmin: >99% Anthropogenic Compounds Endocrine disrupting compounds, Pharmaceuticals and personal care products, Pesticides None to Moderate None to High Data not available Inorganic Compounds Iron, Manganese, Ammonia None to High Moderate to High Manganese: 25–80% * Removal may decrease with lower temperatures Source: Adapted from Brown et al., forthcoming 2 October–December 2020 • Advances in Water Research biofiltration As research demonstrates the effectiveness of biofiltration, the use of biofilters has increased. Biofilter installation at 43 facilities submitting data to the North American Biofiltration Knowledge Base 180 Cumulative Percentage of Filters Sum of Number of Filters Number of Biofilters Installed 160 100% 90% 80% 70% 140 120 60% 50% 40% 100 80 60 30% 20% 40 20 10% 0% 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2054 2006 2076 2008 2098 2010 2010 2012 2013 2014 Unknown 0 Year Installed Source: Brown et al. 2016. WRF has supported a significant amount of research to advance the water sector’s understanding of biofiltration. 37 Biofiltration projects funded by WRF $4,246,123 Cumulative value of the six projects conducted through WRF’s Biofiltration: Defining Benefits and Developing Utility Guidance Research Area. References BROWN, J., G. Upadhyaya, J. Carter, T. Brown, and C. Lauderdale. 2016. North American Biofiltration Knowledge Base. Project 4459. Denver, CO: Water Research Foundation. BROWN, J., G. Upadhyaya, J. Nyfennegger, G. Pope, S. Bassett, A. Evans, J. Carter, V. Nystrom, S. Black, C. Alito, C. Lauderdale, J. Hooper, B. Finnegan, L. Strom, L. Williams Stephens, E. Palmer, E. Dickenson, S. Riley, E. Wert, L. Weinrich, and P. Keenan. Forthcoming. Biofiltration Guidance Manual for Drinking Water Facilities. Project 4719. The Water Research Foundation. Advances in Water Research • October–December 2020 3 Q&A Interview with WRF’s 2020 Outstanding Subscriber Award Winners O n September 1st, WRF presented the 2020Out- their treatment, delivery, and/or management processes standing Subscriber Awards for Applied Research through the successful application of WRF research. WRF to Hampton Roads Sanitation District (HRSD) interviewed representatives from each of these utilities and Metro Vancouver (MV). This award honors subscrib- to learn more about their dedication to applied research ing utilities that have made notable improvements to and innovation. Hampton Roads Sanitation District Charles Bott, PhD, PE, BCEE, Director of Water Technology and Research What does winning WRF’s research, in addition to issue- Outstanding Subscriber Award based research. With so many mean to Hampton Roads San- emerging technologies, so many itation District (HRSD)? We’re emerging needs for new tech- quite proud because we value nology in the wastewater and the work that WRF is doing. The award acknowledges that reuse sectors, and so much capital that will be spent on this we have been an important contributor to research. We have infrastructure in coming years, technology-based research many people contributing to projects, serving on PACs, on can’t be put aside because of the issues of the day. There’s the Research Council, etc. We also provide in-kind and cash always a need to balance issue-based research with the support for research projects that are of interest to HRSD, evaluation, development, and refinement of new technolo- and we are directly involved in many WRF research projects. gies that might be of big benefit to our field. Partial denitrification anammox (PdNA) is an example of that, and WRF Are there specific projects that HRSD has been involved is for the most part the only significant national player in in that you are particularly proud of? There are many. A funding wastewater and reuse technology-based research. couple of current ones involve partial denitrification ana- As HRSD contemplates a capital improvement program mmox, and now we are excited to have partnered with of several billion dollars, the value of this type of research WRF and others to obtain a large EPA grant to continue cannot be overstated. We must continue to innovate. our work in this area. Of note, this new work builds on previous WRF projects that go back as much as 10 years on What are some of the big issues that HRSD is facing, or mainstream deammonification. We’re really excited about anticipates facing, where more research is needed? We the potential technology, we’re excited about the current have a new large initiative of potable reuse by managed project, and we’re excited about the future EPA project. aquifer recharge pending; five treatment plants, 100 mil- Another new project that is very important to HRSD and lion gallons per day. This program is known as the Sustain- just getting started involves ozonation and control of bro- able Water Initiative for Tomorrow (SWIFT), and we are mate in potable reuse (5035). not using reverse osmosis (RO). Rather, SWIFT employs an ozone/biofiltration/GAC-based approach. We’ve been You’re on the Steering Committee of the Leaders Innova- very encouraged by, and eager to participate in, research tion Forum for Technology (LIFT). What other ways has projects related to non-RO potable reuse-based technol- HRSD been involved in LIFT? HRSD is a strong advocate ogy. The portfolio of WRF research on reuse and those for WRF to be able to sponsor and fund technology-based treatment technologies is certainly important. What goes 4 October–December 2020 • Advances in Water Research Outstanding Subscriber right along with that is the need for effective low-level standpoint through emerging technologies, and using nutrient removal. The nutrient program isn’t finished yet. appropriate monitoring technologies to confirm that the There’s a lot of work left to be done to obtain the level water is safe, is critical. Technologies to make the produc- of nutrient removal reliability and sustainability that our tion of whatever quality reuse water is necessary possible industry demands. and cost-effective, and monitoring approaches that assure stakeholders that the water is safe and meets those cri- How has HRSD used research to further its goals? SWIFT teria. That is one of the most important pieces. The other immediately comes to mind. It was the initial work that piece is that those processes and those technologies are WRF funded on non-RO processes for potable reuse that going to require more automation, more sensors, and very gave us the confidence to push ahead on SWIFT with- sophisticated control systems. We must be automated out RO. That has changed our whole organization. WRF because things move too quickly and there is too much helped make that happen. From a nutrient removal stand- happening for a person to address. point, it was original work by WRF, promoting and conducting projects related to sidestream deammonification Is HRSD involved in much intelligent water systems work? that pushed us in that direction, and as an industry, we Our approach has been very measured and careful in this then dove headlong into mainstream deammonification. regard. We look for very specific problems at our treat- We have landed on PdNA as an important route to get ment plants and in our collection/conveyance systems there, but the WRF nutrient research program going back that need to be solved, and manage those issues using 20 years or so is the reason that we are continuing to move these more sophisticated tools, then use that as a model away from our conventional, resource-intensive nitrogen to move forward looking at ever more complex systems. It and phosphorus removal processes into whole new areas. seems that a lot of vendors are claiming it is possible to fix everything all at once! At HRSD, we are taking small steps What do you see as the future of the water sector? Water that folks can understand—identify the specific problem, shortages are going to continue to drive more and more understand the objective, develop, test, and implement reuse opportunities. Making them reasonable from a cost a solution. Metro Vancouver Paul Kadota, MASc, MPA, Collaborative Innovations Manager What does winning of options for wastewater WRF’s Outstanding Sub- sludges. We initiated with scriber Award mean to WRF examination of the Metro Vancouver (MV)? hydrothermal liquefaction Having WRF recognize (HTL) technology that MV validates that we are could potentially displace going in the right direction and continually improving our anaerobic digesters to more thoroughly convert the car- operations in the provision of quality water services. I’d bon that’s being collected by our wastewater treatment like to thank our senior managers for subscribing to the facilities, as well as the beneficial microbial biomass we’re idea that research can lead to invention, which can then cultivating at our facilities. Working with WRF on HTL lead to innovation for business improvement. I also want has been fantastic—to validate the technology, to have to thank our Board of Directors for having the foresight an independent third party validate the excellent bench to set aside resources to fuel good research propositions. test results. That’s the value WRF provides for these rela- Without that support, we couldn’t do what we’re doing. tively risky initiatives that the entire water industry needs to pursue if we want to push the envelope of innovation. Are there specific projects you’ve worked on that you’re particularly proud of? We’re always excited about projects Are there other big issues that MV is facing, or antici- that address real pain points, and one has been the lack pates facing, where more research is needed? What we Advances in Water Research • October–December 2020 5 Outstanding Subscriber see on the horizon are the effects of climate change. We Recently, we’ve been looking into innovation ecosys- have these global effects that are going to impact the way tems. If we want to have a continual pipeline of innova- we do business. We need to do fundamental research to tions at MV, we need to think more about how we’re inter- identify better solutions for the adaptation to, and miti- nally set up for that. The innovation ecosystem needs to gation of, these global issues. These issues are bringing have the right people, but also the right framework, tools, to light that we need to do more with fewer resources. and culture so that staff are encouraged to experiment That means efficiency gains, recovering more energy from with new improvement ideas. MV has done a good job of wastewater, creating greenhouse gas (GHG) credits, and providing the monetary resources necessary to test new reducing costs. ideas and host new technologies. What we’re struggling with right now is the time and effort needed to set up Has MV been implementing actions to address climate demonstration facilities, largely because we don’t have change? Our Board set a goal of achieving region-wide dedicated live-flow spaces for this. We need to create an GHG neutrality in all sectors by 2050. We need to figure easier mechanism for testing, and that innovation ecosys- out our roadmaps towards achieving this target. There tem needs to be part of what we research and how we go are a number of roadmaps being formulated, and we’ve about setting it up in a large organization like MV, and do engaged the broader community to brainstorm ideas in it safely without significant risk to our operating facilities. terms of what we can do in the transportation, building, The real benefit of being part of the WRF family is that water, and other sectors. On the liquid waste side, we’re we share experiences with other utilities. WRF’s initiative looking at how to capture and use the CO2 that’s gener- on LIFT and the Utility Analysis and Improvement Method- ated in our anaerobic digesters—that’s atmospheric cap- ology provides a fantastic venue for sharing experiences. ture. We’re also considering hydrospheric capture of CO2. The duplication of effort can be effectively eliminated by This might be the next frontier of innovation that we in the bringing together peer utilities. water business need to start thinking more about. What do you see as the future of the sector? We need How has MV used research to further your goals? Research to reach out to other sectors and figure out how we can needs to influence the management of our facilities and help each other. We can’t just think about water anymore. have a positive impact on our plans. If our plans change for I would almost challenge the One Water concept and the better because of the innovation that we’re examining, say our future will be more of a One World concept, and then the design, implementation, and operation of that fol- we need to integrate our planning with other operating lows. Along with our collaborators, we research and pilot industries. For example, connecting with your local energy a few techniques and technologies ahead of launching utility or the transportation sector might lead to joint into things. Research has had a significant role, especially solutions to address multiple pain points; the high-tech when we’re making long-term decisions on infrastructure sector could show us a few things about smart systems, or changing management methods. It requires in-depth as well as accelerating innovations. I think that’s where research into the options to determine which path to fol- our future outreach needs to go. Everything is a lot more low. Each jurisdiction will have its own path to investigate. complicated, more integrated, and we need to learn from You might have similar issues in other jurisdictions, but the many other industries and from all fields of science. Let’s localized situation needs to be taken into account when venture outside the comfort of our own industry, develop you’re investigating which management method you want globally impactful solutions at the local level, and catalyze to implement. the establishment of circular economies. 6 October–December 2020 • Advances in Water Research COVID-19 Responding to the Pandemic The Water Research Foundation has taken decisive action to address concerns and research needs related to the COVID-19 pandemic, and will continue to do so into the foreseeable future. By Ashwin Dhanasekar, Christobel Ferguson, Stephanie Fevig, Alyse Greenberg, Julie Minton, Lola Olabode, and Erin Partlan, The Water Research Foundation Advances in Water Research • October–December 2020 7 COVID-19 T hroughout the past year, the world has been seeking information about, and methods to address, the COVID-19 pandemic. Scientific studies demonstrated that the genetic material of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2)—an enveloped RNA virus that causes the disease COVID-19—can frequently be detected in the feces of infected individuals. This suggested a strong indication that the genetic signal of SARS-CoV-2 could be detected in wastewater. Across the water sector, many were also represented (Figure 1). The groups rapidly mobilized to con- survey showed that 54% of respon- International Water Research Summit on COVID-19 duct wastewater surveillance for this dents were already testing for the WITH SO MANY ENTITIES AROUND genetic signal. Wastewater surveil- genetic signal of SARS-CoV-2, and the world conducting wastewater sur- lance is not a new area of research; the remaining 46% were developing veillance, there was an urgent need for it has been critical to detecting the methods with the intention of initi- greater coordination to align research presence of poliovirus and has been ating testing efforts. The results also to accelerate progress in this criti- used to investigate opioid use in indicated that a wide variety of con- cal area. To address this need, WRF communities. What is new, however, trol organisms is being used as pro- held the Virtual International Water is the exploration of its potential to cess controls, including F-specific Research Summit on Environmental provide an integrated, community- phages (e.g., MS2), Hepatitis G, Surveillance of COVID-19 Indicators level indication of the presence mouse hepatitis virus, murine noro- in Sewersheds. More than 50 leading of SARS-CoV-2. virus, pepper mild mottle virus, and water experts from utilities, academia, WRF is dedicated to keeping water human coronaviruses 229E, OC43, consulting, and government partici- sector professionals informed about and NL63. The survey results will be pated in working groups focused on this issue and any measures needed published soon. four specific topics: to protect both water sector workers and public health. To further the science related to SARS-CoV-2 and 54.3 to provide WRF subscribers and partners with the most up-to-date 54.3 50 information available, WRF is coordinating efforts including a meth- 40 ods survey, a virtual summit, new Survey of Wastewater Surveillance Activities Percent research projects, and more. 30 23.9 19.6 20 IN APRIL 2020, WRF CONDUCTED a survey of wastewater surveillance 10 activities related to SARS-CoV-2. Data were collected from 127 individual respondents in the water sector. 0 6.5 6.5 1–49 50–499 The majority of respondents were collecting samples representing service areas of 50,000 people or more; however, smaller service areas 8 Source: WRF 2020a 4.3 500–4,999 5,000–49,999 50,000–499,00 Population Size >500,000 N/A Note: Some respondents represent multiple service areas. Figure 1. Percentage of survey respondents collecting samples from service areas of different sizes October–December 2020 • Advances in Water Research COVID-19 1. Best practices and standard- along with the working group rec- Worker and Public Safety (5029) will ized procedures for the col- ommendations (WRF 2020b). The develop a user-friendly model to esti- lection and storage of waste­- paper can serve as a resource when mate worker viral exposure and envi- water samples. making decisions about conducting ronmental viral release from waste- 2. Best practices for the use of wastewater surveillance and inter- water treatment operations. This will tools to identify the genetic sig- preting and communicating about the help prepare the wastewater industry nal of SARS-CoV-2 in wastewa- resulting data. for the next epidemic or pandemic ter samples. 3. Approaches for the use of Current and Future Research outbreak of highly infectious viruses by providing a quantitative basis to data on the genetic signal of THOUGH RESEARCH ON SARS-COV-2 SARS-CoV-2 to inform trends is new, WRF research has focused on cerns regarding virus persistence, dis- and estimates of community pathogens for many years. There- infection, and potential exposure. prevalence. fore, one step WRF took to incorpo- Measure Pathogens in Wastewater rate SARS-CoV-2 into its research (4989), funded by the California 4. Strategies for communicating to expand upon respond to worker and public con- the implications of wastewater was existing State Water Resources Control Board surveillance results with the pub- pathogen-related projects to include (SWB), focuses on the development lic health community, elected SARS-CoV-2. Environmental Per- of recommendations for the collec- officials, wastewater workers, sistence and Disinfection of the Lassa tion and analysis of pathogen moni- and the public. Virus and SARS-CoV-2 to Protect toring in raw wastewater to develop In the two weeks preceding the Summit, the working groups assessed the current state of knowledge for wastewater surveillance and identified knowledge gaps and research needs. During the Summit Opening Session, held on April 27th, the working groups introduced the key issues in each of these areas and shared their initial progress with the public. Attendees were invited to submit questions and, Table 1. Near-term research opportunities to support wastewater surveillance of SARS-CoV-2 Priority as they refined their recommendations. High Shedding Rate and Genetic Signal Effect of wastewater pre-treatment on genetic signal High Dilution and persistence of the genetic signal in the sewer Shedding Rate and Genetic Signal collection system—targeted integrated study (in well-characterized systems that have good hydraulic models) High Risk Evaluation of potential for infectious virus in wastewater and generation of aerosols High Interpretation of Results Correlations to clinical data for the assessment of community prevalence—how to leverage wastewater surveillance to provide useful data to public health stakeholders High Interpretation of Results Define partnership opportunities and continue collaboration principles, recommended best practices, and near-term research opportunities in each of the four areas. Summit participants identified four Medium Methods Impact of sample collection method (grab vs. composite, duration of composite, time of day) Medium Methods Distribution of virus (or RNA copies) in liquid and solid phases Medium Interpretation of Results How to effectively translate COVID-19 research into pandemic preparedness and wastewater surveillance for future needs Low Methods Which spike organism to use for quality assurance/quality control purposes Low Methods Comparative methods review for enveloped viruses—focusing on the concentration from wastewater matrix key themes for near-term research opportunities to accelerate progress in this work: methods, shedding rate and genetic signal, interpretation of results, and risk. Table 1 shows the research opportunities identified under each theme. The working groups also developed a paper summarizing the expert opinions provided throughout the Summit, Advances in Water Research • October–December 2020 Intra- and interlaboratory assessments on sampling regimes and molecular methods Methods During the April 30th Closing Session, the working groups presented guiding Specific Research Opportunity High over the following two days, the working groups considered these questions Theme Source: Adapted from WRF 2020b 9 COVID-19 better empirical data on patho- high-priority opportunities identi- Wastewater sampling (Figure 2) gen concentrations and variability. fied during the Summit: Interlabo- and analysis began on August 17th, SARS-CoV-2 has been added to the ratory and Methods Assessment of and was conducted through late- list of pathogens of concern for this the SARS-CoV-2 Genetic Signal in September 2020. The results of project, and the research team is Wastewater (5089) and Understand- this project, which WRF anticipates preparing to analyze SARS-CoV-2 ing the Factors That Affect the Detec- publishing in late 2020, will pro- in samples archived since Novem- tion and Variability of SARS-CoV-2 in vide much-needed information on ber 2019, along with current and Wastewater (5093). preferred methods to be used for future samples. Methods performing analyses for wastewater SARs-CoV-2 has also been added Assessment of the SARS-CoV-2 Interlaboratory and surveillance studies and understand- to the list of pathogens of concern for Genetic Signal in Wastewater will ing the limits of detection of existing Collecting Pathogens in Wastewater provide an assessment of the reli- methods. In addition to WRF funds, During Outbreaks (4990), which is ability and repeatability of labo- the Bill & Melinda Gates Founda- determining the feasibility of measur- ratory methods currently being tion contributed funding to support ing pathogen concentrations in Cal- used to test for the genetic signal this project. ifornia wastewater as early warning of SARS-CoV-2 in untreated waste- Understanding the Factors That during community outbreak events. water. Over 60 laboratories volun- Affect the Detection and Variabil- This research effort, also funded by teered to participate in this proj- ity of SARS-CoV-2 in Wastewater, the SWB, involves in-depth litera- ect. The research team ultimately also co-funded by the Bill & Melinda ture reviews of sewage monitoring selected half of these laboratories Gates Foundation, will develop an studies and of seasonal and spatial to answer four key questions: approach to understand the sample trends of enteric pathogen outbreaks in California. WRF has also initiated two new research projects based on the • Which laboratory methods are design factors that affect the detec- best suited for producing reli- tion, variability, and dynamic range able quantitative genetic signals of SARS-CoV-2 genes in wastewater, for SARS-CoV-2? which is crucial for the interpretation • To what extent are laboratories lance. This research will encompass able to reproduce a range of scales by conducting a sample results by sampling and analytical program following docu- in different locations within well- mented quality characterized community sewer- assurance/qual- sheds. The results of this project, ity control (QA/ which will be available in October QC) procedures? 2021, will include a framework with • Which steps specific recommendations for sam- within a given ple design to enable implementa- method are most tion of wastewater surveillance at critical to ensure three scales: large urban sewersheds, accuracy and precision? • What is the limit of detection for the recovery of a Figure 2. Wastewater sampling 10 of results from wastewater surveil- medium-sized regional sewersheds with small bore sewers, and small regional systems. Next Steps genetic signal for MOVING FORWARD, WRF PLANS SARS-CoV-2 in to fund additional research related wastewater, and to wastewater surveillance. For how does it vary example, the goals and approach across the avail- are currently being developed for able methods? the project, Impact of Storage and October–December 2020 • Advances in Water Research COVID-19 • INTELLIGENT WATER NETWORKS Pre-Treatment Methods on Signal Strength of SARS-CoV-2 Genetic References Signal in Wastewater. WRF will con- WRF (The Water Research Foundation). 2020a. “Virtual International tinue to gather key information from Water Research Summit on Environmental Surveillance of COVID-19 experts in the fields of infectious Indicators in Sewersheds—Opening Session.” April 27, 2020. https:// disease control, virology, water engi- www.waterrf.org/event/water-research-foundations-virtual-international- neering, outbreak epidemiology, and emergency response, and provide water-research-summit-environmental. ———. 2020b. Wastewater Surveillance of the COVID-19 Genetic Signal in resources and learning opportunities Sewersheds: Recommendations from Global Experts. Accessed July 27, to keep the water sector up-to-date 2020. https://www.waterrf.org/sites/default/files/file/2020-06/COVID19_SummitHandout-v3b.pdf. on these key topics. More information related to WRF’s COVID-19 work is available on the ———. 2020c. “COVID-19 Guidance and Resources.” Accessed August 3, 2020. https://www.waterrf.org/covid-19-guidance-and-resources. WRF website (WRF 2020c). Intelligent Water Networks I (4714) ntelligent Water Networks Summit gatheredinforma- intelligent water utility maturity model framework was tion about experiences with intelligent water networks, developed to assess a utility’s technological maturity and facilitated the distribution of this information to and support the development of strategies, budgets, and interested organizations. Three regional workshops were implementation plans for improving the utility’s efficiency held across the United States, followed by a summit where and customer service. A maturity model tool was also water utilities presented case studies addressing topics developed to assist utilities in conducting self-assessments such as managing wastewater overflows, non-revenue using the maturity model framework. A recording of the water reduction, water quality monitoring, and source August 2020 webcast on this project is available for view- water monitoring using standalone vendor solutions. An ing on the WRF website. Utility UNITS >>> FUNCTIONS >>> Water Operations Source Water Management Wastewater Operations Support Systems Collection System Operations IT Systems Water Treatment Plant Operations Wastewater Treatment Plant Operations Finance Distribution System Operations Disposal/Receiving Water Management Human Resources Maintenance Maintenance Customer Service Engineering Major operational units and their typical functions Advances in Water Research • October–December 2020 11 INNOVATION in ACTION Q&A with Aisha Niang with a utility that was also under In my spare time, I’m an avid trav- a consent decree, learn about an eler and photographer. I’ve traveled to in-depth approach to community out- more than 26 countries and have vol- reach, gain insight into staffing needs, unteered on service projects in Mexico, and recognize the sheer magnitude Puerto Rico, the Bahamas, and Peru. of what Houston Water is going to T he Scholarship embark on. The lessons learned gave What challenges has Houston Water invaluable insight from the host utili- faced that made you pursue a SEE ties, and the knowledge, experience, IT scholarship? Due to extensive Exchange and relationships gained because of flooding of treatment facilities and Experience for Innovation & this trip will be utilized as Houston numerous historic storm events, Technology (SEE IT), a LIFT Water moves forward. Houston Water is in the initial plan- initiative guided by The Water Aisha Niang is the Assistant Direc- ning and design stages for consoli- Research Foundation, the Water tor for Wastewater Operations dation and flow diversion projects for Environment Federation, and the at Houston Water, where she has various WRRFs. National Association of Clean Water worked for 12 years. She oversees the With a wastewater system that is Agencies, provides scholarships for day-to-day operations of Houston’s comprised of 39 WRRFs, 383 lift sta- utility personnel to visit other utili- WRRFs and lift stations, which col- tions, and 6,200 miles of collection ties with innovations of interest and lect and treat wastewater for approx- lines, it was decided to reduce certain share experiences with their peers. imately 2.2 million customers. Aisha assets and expand others to accom- Innovations can include new technol- manages plant optimization, mainte- modate an increase in flow. Houston ogies and processes, but also novel nance, electrical, odor control, bio- Water is also using the tunneling sys- approaches to service, operations, solids, residuals handling, and service tems for the elimination of SSOs by and finance. SEE IT provides hands-on contacts. Following is a summary of lowering capacity issues and stabiliz- interaction and gives participants the Aisha’s thoughts on her experience ing rising costs via control of oper- perspective and information needed with SEE IT. ations and maintenance (O&M) and to accelerate adoption of innovations at their own facilities. capital expenditures. Can you tell me more about yourself? Houston Water, a 2019 SEE IT par- I began my career in the water indus- What were the biggest benefits of ticipant, is in the initial planning and try as a process engineer for DC Water being able to visit the various facil- design stages for consolidation and at their Blue Plains facility. I then took ities and meet the practitioners in flow diversion projects for their water a position as an operations consul- person? It made sense to apply for resource recovery facilities (WRRFs). tant in New York City for a $4 billion the SEE IT scholarship to be able to These projects will reduce plant facil- expansion project. I received my Bach- travel and have in-person exchanges ities from 39 to 31, as well as mini- elor of Science degree mize the number of lift stations that in are maintained and operated. Hous- from Howard University, ton Water believes that tunneling is and Master of Science the best option to eliminate sanitary degree in Civil Engineer- sewer overflows (SSOs). ing from Catholic Uni- Civil Engineering The SEE IT field visits to DC Water, versity. I am a licensed Seattle Public Utilities, and Panama Professional Engineer allowed Houston staff, including Aisha in Texas and hold dual Niang, to view different phases of licensure as a water and tunneling projects, have an exchange wastewater operator. 12 October–December 2020 • Advances in Water Research SEE IT with utilities that have already tra- Have any of those relationships con- create stronger relationships with versed that path that Houston Water tinued after your trip? Various rela- other utilities. was going to walk on. To be able to tionships have formed from Houston stand in construction sites and expe- Water’s trips to Seattle Public Utilities Since your trips, has Houston Water rience their sheer magnitude, visit and DC Water. Conference calls were started implementing any of the neighborhoods that are in the plan- held to further discuss community technologies you saw? Houston Pub- ning phase for tunnel implementation, engagement, outreach approaches, lic Works is well underway with the and to see the community impacts is lessons learned, and community planning and design phases for four not something that you can just read involvement for tunneling projects. to five tunneling projects to improve about—you should SEE IT in person. An outlier relationship also formed our wastewater system. It is an excit- Close collaboration along with the with regard to asset management ing time for Houston and a monumen- field trips sped up the learning, adop- and hydraulic modeling. The SEE IT tal one for Houston Water that we tion, and implementation of tunnel scholarship afforded the ability to enter into with confidence because innovations. The LIFT SEE IT exchange of our participation in SEE IT. provided a foundation to pave the way to avoid project setbacks that other utilities have encountered. What were some highlights and takeaways from your trips? The SEE IT trips allowed us to: • Gain insight into how the delivery methods began and evolved. The trips provided ideas without creating a whole new deliv­ery method. • Reinforce Houston Public Works’ organizational structure by comparing it to other municipalities. • Learn about the different methods utilized to deliver major projects within deadlines. • Understand the many aspects an undertaking of this magnitude will take—from public relations to organization to logistics. • Obtain invaluable resources and vital tips on how to engage with the community for a large-scale project like tunneling. • Gain an awareness of the unforeseen hurdles that were faced, which provided us with a broader perspective of the significant impacts of a tunneling project. • Develop more mindfulness regarding safety for projects of this size. Advances in Water Research • October–December 2020 13 Biofiltration Biofiltration: 30 Years of Research and Guidance 14 October–December 2020 • Advances in Water Research Biofiltration’s potential savings over costly, energy-intensive, or waste-generating advanced treatment techniques are seen as a significant benefit for utilities. By H. Grace Jang, The Water Research Foundation; and Jess Brown, Carollo Engineers B iological filtration(biofiltra- determine biofiltration effectiveness tion) is the operational prac- at removing contaminants, define tice of managing, maintaining, benefits and communicate them to and promoting biological activity on key stakeholders, and provide utility granular media in a filter to enhance guidance on optimizing biofiltration. the removal of organic and inorganic This research has helped utilities constituents before treated water is manage and address the challenge introduced into the distribution sys- of optimizing the biological filtration tem (Brown et al. 2016). Biofiltration process. WRF’s biofiltration projects has been used as a part of drinking funded through the Research Priority water treatment since the early 1900s. Program are highlighted in Table 1. Although biofiltration has a long history of use and holds great promise as an effective, economic, and sustainable operational practice, it has Biofiltration Guidance Manual (4719) ALTHOUGH THE DRINKING WATER not been utilized to the full extent community has gained a greater possible due to public perception understanding and knowledge about problems and resistance to the inten- biofiltration in recent years, there tional use of microorganisms within had not been a single point of ref- water treatment processes. In recent erence (i.e., guidance document) years, however, new stringent regula- that clearly identified how to design, tory and technological developments operate, monitor, and maintain bio- have encouraged more utilities to filters to date. The industry experi- consider biofiltration to treat their ence indicates that most biofilters drinking water. today are still operated on an inci- WRF’s Biofiltration Research Area WRF HAS SUPPORTED consider- dental basis without a clear strategy for optimizing biological activity or overall biofilter performance. This is largely due to the absence able biofiltration-related research of a consolidated, central reference over three decades to advance the for biofiltration design and opera- science and engineering of biofiltra- tion. Furthermore, utilities that have tion. WRF research helped the water never employed biofiltration need community to establish baseline guidance on starting and monitor- knowledge on the design and oper- ing biofilters. Recognizing these ation of biofilters (e.g., filter media needs, WRF supported Biofiltration type, filter backwashing). Further- Guidance Manual for Drinking Water more, in 2012, WRF launched the Facilities (Brown et al., forthcoming) biofiltration research area (formerly to provide the most comprehensive known as a focus area, WRF 2019) to set of practical biofilter design and 15 Biofiltration operational guidance materials cur- rate biofilters for drinking water util- Manual Content rently available to the drinking water ities. The project team drew upon THE INTENT OF THIS MANUAL ISto industry and to improve the effec- a cross-section of drinking water facilitate technology/knowledge trans- tiveness and maximize the reliability professionals familiar with this treat- fer for biofiltration and provide “how-to” ment approach to ensure that the guidance in an easy-to-use form. The guidelines were widely accepted. manual is organized as follows: of biofiltration. Development of the Manual THIS MANUAL COLLATES FINDINGS Throughout the development of the Chapter 1: Background describes a manual, over 30 professionals rep- biological filter, gives a historical per- of previous research and applica- resenting utilities, regulatory agen- spective, outlines the theory of the tions to create a comprehensive cies, engineering firms, academic process, and reviews biofilm characteristics and dynamics. reference that guides the design, institutions, and manufacturers operation, monitoring, conversion, reviewed the guidance manual and testing, and optimization of rapid provided feedback. Chapter 2: Monitoring Tools and Instrumentation discusses monitoring Table 1. Six projects funded under WRF’s Research Priority Program North American Biofiltration Knowledge Base (4459) This project compiled industry practices into an accessible biofiltration registry and knowledge base, and developed a compendium of research and practical application information gathered from utilities, universities, manufacturers, and consultants across North America. The purpose of the Knowledge Base is to provide an easy-to-use resource for utilities wanting to know more about biofiltration or seeking to optimize a system already in operation. Principal Investigator: Jess Brown, PhD, PE, Carollo Engineers Biofilter Conversion Guidance Manual (4496) This project discussed key parameters/aspects associated with the planning, evaluation, implementation, and optimization phases of biofilter conversion and provided detailed guidance on tasks to be completed at each phase. The guidance manual can improve the likelihood of successful biofilter conversion while helping to minimize unintended negative consequences. The biofiltration assessment tool can be downloaded: https://www.waterrf.org/resource/biofilter-conversion-assessment-tool Principal Investigator: Jess Brown, PhD, PE, Carollo Engineers Optimizing Biofiltration for Various Source Water Quality Conditions (4555) This project summarized the current state of knowledge and compiled methods currently used to control and optimize biofiltration. It provided guidance with supporting data for three biofilter optimization strategies (enhancing upstream oxidants, microbial activity, and filter backwashing), focusing on plant optimization that involves only low-impact, low-cost capital improvements. The balance between treatment objectives and biofilter optimization with plant-specific water quality and treatment goals was considered for guidance. Principal Investigator: Chance Lauderdale, PhD, PE, HDR, Inc. Simultaneous Removal of Multiple Chemical Contaminants Using Biofiltration (4559) This project collected information and performance data from the literature, as well as pilot- and full-scale studies focusing on key design and operational parameters and water quality characteristics that may influence the simultaneous removal of multiple contaminants. Based on the information collected during this study, a multi-contaminant removal matrix was developed, which considered the following key design and operational parameters: media type, biofilter influent water characteristics, pre-oxidation, and empty bed contact time (EBCT). This project can help water utilities achieve maximum simultaneous removal of multiple chemical contaminants using biofiltration without compromising the existing objectives of the filtration process. Principal Investigator: Eric Dickenson, PhD, Southern Nevada Water Authority Guidance Manual for Monitoring Biological Filtration of Drinking Water (4620) This project evaluated biofiltration process and water quality monitoring tools and discussed their potential benefits for use by utilities. Three strategies for biofiltration monitoring (biological parameters, natural organic matter and water quality, and filter hydraulics and operation) were assessed, and practical and quantitative guidance on how to use the tools when they are appropriate, and how to interpret the data, was provided. Principal Investigator: Jennifer Hooper, PE, CDM Smith Inc. Biofiltration Guidance Manual for Drinking Water Facilities (4719) Detailed information is provided throughout this article. 16 October–December 2020 • Advances in Water Research Biofiltration tools (filter integrity monitoring, for converting their conventional filters design, operation, monitoring, and hydraulic monitoring, water quality to biofilters. Chapter 5: Greenfield Bio- maintenance of biofilters to achieve monitoring, biological monitoring) and filtration is for newly proposed biofil- a multitude of water quality improve- provides recommendations for biofil- tration facilities that need guidance on ments. This manual will facilitate a tration plants that inform operators of how to evaluate, design, and operate broader and more successful imple- the health of their filters and when to new biofilters. This chapter covers mentation of this treatment approach. take action to prevent a lapse in water planning, design, and operation of quality. This chapter also describes greenfield biofiltration. Several exam- Additional Pertinent WRF Projects how to develop a monitoring strategy. ples of greenfield biofiltration plants WRF projects that are relevant to this and case study facilities are included THROUGH OTHER RESEARCHpro- chapter are listed in the sidebar. to illustrate different applications, pro- grams, WRF has funded a variety cess difficulties, and approaches to of additional projects relevant to overcome these difficulties. biofiltration. There are three types of biofiltration applications, and the guidance manual is organized to reflect these applica- WRF has a number of projects tions. Chapter 3: Optimizing Exist- that are relevant to these chapters ing Biofiltration Plants is for utilities (see sidebar). Addressing Emerging Issues: DBP Formation and Pathogens that are already operating biofilters Chapter 6: Operation and Mainte- SEVERAL WRF PROJECTS EXPLORED and are focused on improving biofil- nance summarizes key operational practical implications of biofiltra- ter performance. This chapter covers and maintenance considerations for tion, including disinfection byprod- optimization planning and associated biofiltration, and Chapter 7: Biofiltra- uct formation and pathogen control. strategies to deliver improvements tion Testing addresses eight key ques- Impact of Filtration Media Type/Age in overall treatment efficiency and tions that a well-designed testing plan on Nitrosamine Precursors (4532; PI: water quality. Chapter 4: Converting should answer (Figure 1). Zia Bukhari, American Water) studied Conventional Filters to Biofilters is for This manual also includes 12 appen- how effectively biofiltration processes utilities considering converting exist- dices as supplemental and stand-alone can remove nitrosamines, specifically ing filters to biofilters that will need reference materials (Figure 2). N-nitrosodimethylamine (NDMA), or guidance on steps for transitioning to Water professionals will greatly ben- their precursors that may ultimately and enhancing biofiltration. Convert- efit from this manual as it provides form nitrosamines due to disinfection ing conventional filters to biofilters can clear guidance about planning, testing, help realize multiple benefits for drinking water treatment plants, including improved organics and contaminant removal, robust system per- 1. Define Testing Objectives • What water quality and/or operational goals am I trying to achieve? 2. Benchmarking Water Quality and Treatment Characteristics • What water quality and treatment characteristics do I need to account for? 3. Selecting Testing Scale(s) • Is desktop evaluation, bench-, pilot-, demonstration-, or full-scale testing most appropriate for my goals? 4. Designing a Desktop Evaluation • Is biofiltration suitable for my facility? • How do I develop a business case for conducting biofiltration testing? 5. Designing Bench, Pilot, or Demonstration Tests • What should my testing plan include? • What equipment do I need? • How do I assess performance? 6. Overcoming Common Testing Challenges • How can I further improve my testing plan? 7. Understanding Expected Outcomes • When should I move to the next phase of testing? • When is testing complete? 8. Resource Planning • What resources do I need to allocate towards testing to ensure I meet my goals? • How do I manage cost? formance, lower chemical requirements, and lower operational costs. However, there are several challenges that utilities could encounter while they convert conventional filtration to biofiltration. Therefore, careful consideration and planning should be conducted before conversion implementation. This chapter helps utilities avoid errors or omissions in the design and operation of biofiltration facilities and provides a framework Source: Brown et al., forthcoming Figure 1. Eight key testing plan questions Advances in Water Research • October–December 2020 17 Biofiltration it is sustainable Sample Testing Plans (Appendix L) Biofiltration Terminology (Appendix A) Full-Scale Biofiltration Plant Compilation (Appendix K) Frequently Asked Questions (Appendix B) Biofiltration Calculations (Appendix C) Biofilter ConversionCase Studies (Appendix J) Operations Checklist (Appendix D) Optimization Decision Trees (Appendix I) and can be used to remove pathogens and a variety of organic compounds. Demonstration of High Quality Drinking Water Production Using Multi-Stage Biofiltration Optimization References (Appendix H) Troubleshooting Guide (Appendix E) Ozone Biologi- cal Filtration: A Comparison of Monitoring Standard Operating Procedures (SOPs) (Appendix F) Direct Potable Tools Compendium (Appendix G) Reuse with Graphic Courtesy of Carollo Engineers (DPR) Existing Indirect Figure 2. Twelve appendices in the manual Pota- ble Reuse (IPR) (4777; PI: Denise in drinking water distribution systems. on the selection for opportunistic Similar to prior studies, this proj- pathogens. This project examines Funk, Brown and Caldwell) evaluated ect found that NDMA removal data microbial community structure and and validated the feasibility and effec- showed considerable variability, likely abundance of opportunistic bacterial tiveness of ozone-BAF treatment in due to multiple factors (e.g., analytical, pathogens in full-scale biofilters for reuse applications. This study found seasonal, geographic, and operational). drinking water production. The pre- that ozone-BAF provided potable This project suggested that effective liminary data indicate that multiple water quality at a 15% blending ratio NDMA management will require a mul- variables shape microbial community (e.g., 15% advanced treated water tifaceted approach using optimized structure and richness in granular acti- and 85% lake water) without the use coagulant/polymer doses, enhanced vated carbon (GAC) biofilters and, that of RO. Another key finding from this physical separation (e.g., sedimenta- among those variables, the type of fil- study was significant cost savings— tion and empty bed contact times) in ter underdrain and exposure to chlo- less than half the cost of full advanced conjunction with strategic planning for ramine during filter backwash select treatment. selecting the disinfection approach for non-Tuberculosis Mycobacteria (specific disinfectant and dosing location in treatment train). Biological Filtration: NDMA Control or Source of Precursors? (4669; PI: Ashley Evans, populations in the GAC. Applying Biofiltration in Reuse Applications In addition, several projects are underway to examine the operational optimization, performance improvement, and treatment requirements for reuse applications. The WRF projects Arcadis), evaluated the impact of TRADITIONALLY, REVERSE OSMOSIS listed below are related to biofiltration biofiltration on NDMA precursor con- (RO)-based treatment has played a in water reuse. centrations and provided guidance to key role in achieving treatment goals biofiltration facilities to control the for- in reuse applications. However, it has Treatment Processes for Potable mation of NDMA. some technical challenges such as Reuse Applications (4776), PI: Zia Optimizing Filter Operation in an • Optimization of Ozone-BAC Bukhari, American Water high energy demand, membrane foul• Evaluation of CEC Removal by Ozone-Biofiltration Plant to Reduce ing, and brine disposal. As an alterna- Selection for Opportunistic Pathogens tive option, combining ozone with bio- Ozone/BAF Treatment (4832), in Drinking Water Production (4743; logically active filtration (ozone-BAF) PI: Keel Robinson, Trussell Tech- PI: Brian Steglitz, City of Ann Arbor) has drawn attention. This treatment is studying the impact of disinfectant approach is already an accepted drink- exposure during ozone-biofiltration ing water treatment process because 18 nologies, Inc. • Assessing the Impacts of Backwash Practice on Biofiltration October–December 2020 • Advances in Water Research Biofiltration • Operation and Performance Summary (5043), PI: Shih-Chi Weng, Gwin- THE USE OF BIOFILTRATION HAS ing, and optimizing biofiltration and implementing, enhancing, monitor- nett County Water Resources been an effective, economic, and enhancing drinking water treatment Understanding and Improving sustainable means of providing high- effectiveness and communication. Reuse Biofilter Performance quality water to meet water quality Producing the comprehensive biofil- during Transformation from GAC standards. Over the past 30 years, tration guidance manual is an excel- to BAC (5092), PI: Gayathri Ram WRF has played a significant role in lent example of WRF’s contribution to Mohan, Gwinnett County providing guidance documents for the biofiltration area and overall water industry. Beyond drinking water treat- Relevant WRF Biofiltration Projects Monitoring Tools: • A Monitoring and Control Toolbox for Biological Filtration (4231), PI: Patrick Evans, CDM Smith Inc. • North American Biofiltration Knowledge Base (4459), PI: Jess Brown, Carollo Engineers • ment, interest in ozone-biofiltration has rapidly expanded to advanced wastewater treatment and water reuse applications. WRF will continue working to bridge the gap for biofiltration application between drinking water and reuse water. Full-Scale Engineered Biofiltration Evaluation and Development of a Performance Tracking Tool (4525), PI: Jennifer Nyfennegger, Carollo Engineers • Guidance Manual for Monitoring Biological Filtration of Drinking Water (4620), PI: Jennifer Hooper, CDM Smith Inc. Biofiltration Optimization: • Engineered Biofiltration for Enhanced Hydraulic and Water Treatment Performance (4215), PI: Jess Brown, Carollo Engineers • Optimizing Engineered Biofiltration (4346), PI: Chance Lauderdale, HDR, Inc. • Optimizing Biofiltration for Various Source Water Quality Conditions (4555), PI: Chance Lauderdale, Carollo Engineers • Simultaneous Removal of Multiple Chemical Contaminants Using Biofiltration (4559), PI: Eric Dickenson, Southern Nevada Water Authority • Optimizing Biofiltration (BAF) and Integrating BAF Into Existing Treatment (4731), PI: Jess Brown, Carollo Engineers • Optimizing Biofiltration for Improved Manganese Control under Cold-Water Conditions (4749), PI: Ashley Evans, Arcadis Conversion to Biofiltration: • Optimizing Filter Conditions for Improved Manganese Control During Conversion to Biofiltration (4448), PI: Chance Lauderdale, HDR, Inc. • Biofilter Conversion Guidance Manual (4496), PI: Jess Brown, Carollo Engineers Greenfield Biofiltration: • Engineered Biofiltration for Enhanced Hydraulic and Water Treatment Performance (4215), PI: Jess Brown, Carollo Engineers • • References BROWN, J., G. Upadhyaya, J. Carter, T. Brown, and C. Lauderdale. 2016. North American Biofiltration Knowledge Base. Project 4459. Denver, CO: Water Research Foundation. BROWN, J., G. Upadhyaya, J. Nyfennegger, G. Pope, S. Bassett, A. Evans, J. Carter, V. Nystrom, S. Black, C. Alito, C. Lauderdale, J. Hooper, B. Finnegan, L. Strom, L. Williams Stephens, E. Palmer, E. Dickenson, S. Riley, E. Wert, L. Weinrich, and P. Keenan. Forthcoming. Biofiltration Guidance Manual for Drinking Water Facilities. Project 4719. The Water Research Foundation. WRF (The Water Research Full-Scale Engineered Biofiltration Evaluation and Development of a Performance Foundation). 2019. “Biofiltra- Tracking Tool (4525), PI: Jennifer Nyfennegger, Carollo Engineers tion: Defining Benefits and North American Biofiltration Knowledge Base (4459), PI: Jess Brown, Carollo Developing Utility Guidance.” Engineers https://www.waterrf.org/news/ • Biofilter Conversion Guidance Manual (4496), PI: Jess Brown, Carollo Engineers biofiltration-defining- • Optimizing Biofiltration for Various Source Water Quality Conditions (4555), benefits-and-developing- PI: Chance Lauderdale, HDR, Inc. utility-guidance. Advances in Water Research • October–December 2020 19 Microbiome Chicago Area Waterway System Microbiome Study 20 October–December 2020 • Advances in Water Research An understanding of the microbial community structure—the microbiome­— of urban waters could provide insight into the human health risks associated with recreational use of these waters. By Lola Olabode and Alyse Greenberg, The Water Research Foundation; Mark Grippo, Argonne National Laboratory; Allison Fore and Geeta Rijal (Retired), Metropolitan Water Reclamation District of Greater Chicago A n integral part of the urban may pose a risk to humans engaged water cycle is sewer infra- in recreational activity (Figure 1). structure. Treated waste- Therefore, an understanding of the water, and to a lesser degree microbial stormwater, make up a significant (microbiome) of urban waters could community structure contribution to total water volume provide insight into the human health in the Chicago Area Waterway Sys- risks associated with recreational use tem (CAWS). As stormwater and of these waters. This will also help wastewater are released into natu- prioritize actions needed to achieve ral waterways, traces of human and and maintain the quality of the water animal microbiomes are reflected for primary contact recreation such in the composition of these waters. as swimming. Consequently, the CAWS contains a Microbial source tracking (MST), wide range of human- and animal- also known as microbial source iden- associated bacteria, some of which tification, is a DNA-based technology THE CAWS IS COMPRISED OF WATERWAYS, DAMS, LOCKS, AND PORT FACILITIES.The Metropolitan Water Reclamation District of Greater Chicago (MWRD) manages the operation of water reclamation facilities to ensure effective conveyance of treated wastewater, protect water quality, accommodate commercial and recreational navigation, provide flood control, and produce hydroelectric energy. The majority of the CAWS is comprised of man-made canals. The MWRD reversed the Chicago River in 1900 by constructing the Chicago Sanitary and Ship Canal to take wastewater away from Lake Michigan to send downstream to address a public health issue and protect the source of the region’s drinking water. The success of the Sanitary and Ship Canal led the MWRD to construct two additional canals, totaling 61.3 miles of canals and waterway improvements. Other parts of the CAWS are natural streams that have been dredged, straightened, widened, realigned, and otherwise modified, providing a unique engineered system with a deep history that has required years of investment and improvement. This work has protected the drinking water supply, prevented fluvial flooding, and revitalized a once neglected river enlisted to convey sewage into a valued public amenity and habitat for thriving wildlife. Now with the help of this groundbreaking study, we gain a closer glimpse into the colorful and transformative history that is the CAWS. 21 Microbiome that can be used to determine how The Terrence J. O’Brien Water Recla- Study Goals much of the microbial fecal contam- mation Plant (O’Brien WRP) in Skokie, THE OVERALL GOALS OF THISstudy ination in an aquatic environment is IL, treats an average of 230 million were to (1) characterize the microbial due to humans or other animal spe- gallons of wastewater per day (mgd), composition of the CAWS over time cies. To better understand how bac- has the capacity to treat 450 mgd, and space, (2) determine the poten- terial communities vary with weather and serves more than 1.3 million peo- tial sources of bacteria in the CAWS, and location within the CAWS, this ple. The Calumet WRP in Chicago, IL, and (3) determine the impact on technology, which uses sequencing has a capacity to treat 430 mgd and these characteristics following dis- of molecular DNA, was used to char- serves a population of more than 1 mil- infection at the two wastewater rec- acterize the bacteria found in water lion people. lamation plants and the operation of and sediment at 16 different sites In 2015, the MWRD implemented the TCR. Two techniques were used across the CAWS during a seven- ultraviolet radiation-based disinfec- to perform molecular characteriza- year period (2013–2019). This work tion technology at the O’Brien WRP tion of the CAWS microbiome. The provides the most detailed investiga- in order to inactivate harmful bacte- technique called 16S rRNA amplicon tion of microbial dynamics in an urban ria and pathogens in effluent released sequence analysis was used to iden- waterway ever attempted. The study into the North Shore Channel and tify bacterial groups (taxa) present also helped to determine the impact North Branch of the Chicago River. At in the CAWS. The 16S rRNA gene is of recently implemented upgrades to the Calumet WRP plant, a chlorination- necessary for ribosome assembly, two Metropolitan Water Reclamation and dechlorination-based disinfection contains variable sequence regions District of Greater Chicago (MWRD) technology was implemented. Fur- that are specific to different micro- water resource recovery facilities and thermore, as part of the Chicago Area bial species, and can therefore be stormwater management controls. Tunnel and Reservoir Plan (TARP) that used for taxa identification. Shot- Facility Improvements and Operations is designed to intercept the combined gun metagenomic sequencing was sewer overflow (CSO) discharges, the used to assess functional attributes Thornton Composite Reservoir (TCR) of the microbial community such in the Calumet WRP service area as virulence. Unlike the 16S rRNA district responsible for treating waste- became operational in December 2015. approach, which targets a specific water and providing stormwater The TCR provides 7.9 billion gallons of gene sequence, shotgun metag- THE MWRD IS A SPECIAL-PURPOSE management in Cook County, Illinois. storage to capture combined storm- enomics sequences genes from a Wastewater and stormwater from the water and sewage that would other- broad array of microbial taxa. MWRD service area flow to seven wise have overflowed into the CAWS Another goal was to develop a water reclamation plants (WRPs). Two during storm events, which is then model that could predict fecal indi- of the WRPs implemented effluent eventually pumped to the Calumet cator bacteria for a given set of disinfection upgrades in recent years. WRP for treatment. environmental conditions. Therefore, Figure 1. Recreational activities on the CAWS 22 October–December 2020 • Advances in Water Research Microbiome several modeling approaches were reduction in sewage indicator bac- detection to include microorganisms also tested to predict fecal indica- teria can be attributed to the imple- and viruses that are not detected tor bacteria concentrations at any mentation of the disinfection process by traditional approaches. In this point along the CAWS under various at the O’Brien WRP. Furthermore, the study, 16S rRNA amplicon and shot- seasonal and hydrologic conditions reduction in sewage-associated bac- gun metagenomic sequencing pro- and estimate the probability that teria following the implementation vided a detailed characterization and fecal coliform concentrations will exceed regulatory standards. Results MOLECULAR CHARACTERIZATION of bacteria indicates that the CAWS bacterial community is diverse, with more than 30,000 species of bacteria in the water and sediment alone. The majority of microbial diversity in CAWS water samples can be largely attributed to effluent, sewage, CAWS sediment, river water, and fish mucus samples, with animal- or human- improved understanding of micro- This is the most detailed investigation of microbial dynamics in an urban waterway associated feces contribution bial communities in the CAWS and how they respond to infrastructure improvements to address water quality. In addition, molecular methods can identify many of the sources that contribute to the diverse microbial community in the CAWS. These molecular approaches enhance the utility of existing water quality assessment tools by providing better characterization of pathogens and their virulence profile and increased understanding of the sources of microbial communities. being extremely low. The bacterial of disinfection and the TCR demon- Improving the current CAWS fecal groups (taxa) indicative of effluent strated by the molecular analysis was indicator bacteria model should start and sewage were mostly bacteria confirmed by the results of monthly with collecting fecal coliform samples whose abundance is increased by fecal coliform analysis determined by 50 times per water quality sampling the wastewater treatment process the conventional coliform plate count site per month from March to Octo- and sewage infrastructure, and are method. These results suggest that ber. In addition, the model should be not considered to be human patho- the disinfection processes imple- “retrained“ and “retested” on an annual gens. Across the CAWS, there was mented at the O’Brien and Calumet basis, thereby taking into account an increase in sewage indicator WRPs were effective at reducing dis- important, incremental changes in bacteria during the wet weather charges of fecal and sewage indica- the system such as land use/land events, irrespective of whether tor bacteria into the CAWS. cover and structural changes in the CSOs occurred during these events. None of the modeling approaches hydraulic system (e.g., TARP). How- Compared to the pre-disinfection provided satisfactory accuracy in ever, these improvements, particularly period (2013–2015), in the four predicting fecal coliform levels. This an increase in monitoring frequency, years post-disinfection (2016–2019) is likely because the monthly sam- will be difficult to achieve given the there was a sequential decrease of pling frequency of the fecal coliform effort required. sewage and fecal indicator bacte- data available was not sufficient for The study demonstrated the util- ria in both the treated WRP efflu- model training. However, this effort ity of microbiome monitoring for ent and river water samples col- produced an operational model for assessing improvements to water lected downstream of the Calumet predicting fecal coliform density and quality and provides a deeper under- and O’Brien WRPs. In the Calumet regulatory exceedance probability. region, the decrease in the sewage indicator bacteria was likely related to disinfection at Calumet WRP and Challenges, Lessons Learned, and Benefits standing of the microbial makeup of a unique waterway system. It also gives an indication of the potential of water quality improvements. the decrease in CSO events follow- WHILE CONVENTIONAL COLIFORM While this study focused on assess- ing implementation of the TCR. In plate counting is still valuable, the ing improvements to treatment the northern area of the CAWS, the use of DNA sequencing can broaden plants, other improvement efforts, Advances in Water Research • October–December 2020 23 Microbiome • GREENHOUSE GASES • BIOFUEL such as increasing riparian habitat, more than 120 years ago. The results infection of rates of pathogens like could also be assessed using such of this unprecedented research can SARS-CoV-2 has been demonstrated genetic monitoring approaches. As be used to guide development of in several cities. Sampling the sewer the MWRD continues to expand standards and implementation of system in multiple locations in the TARP and invest in new water rec- actions to improve water quality for city is a cost-effective alternative to lamation plant technologies, results primary contact recreation in the tracking infections by testing individ- of this study can serve as a roadmap CAWS and a greater understanding uals. Other public health issues, such to achieving potential water quality for all waterways. as the presence of antibiotic resis- improvements not envisioned since In addition, the utility of using tant bacteria, can also be effectively the MWRD engineered the rever- microbiome monitoring at treat- monitored using genetic monitor- sal of the flow of the Chicago River ment plants to track the spread and ing methods. Modeling Collection System Greenhouse Gases (4885) I t is important for wastewater utilities to understand and production of methane in sewers and its potential contri- address the physical, chemical, and biological influences bution to the overall GHG emissions inventory. in the sewer within a single, comprehensive model. Con- veyance Asset Prediction System (CAPS): Modeling and Mitigation developed a tool and techniques for improving the assessment of, and proactive planning for, corrosion, odor, and greenhouse gas (GHG) evolution in sewer collection systems. By using these resources to holistically evaluate collection systems, utilities can make informed decisions, adopt mitigation methods, and implement capital programs in a coordinated, prioritized, sciencebased approach. In addition, the project addressed the Experimental setup for the measurement of dissolved gas Transportation Biofuel Development H ydrothermal liquefaction without drying, and eventually be renewable, cost-effective feedstock quickly converts the waste used for finished fuels. Building upon for biocrude production as a precursor solids from water resource previous research, including projects for liquid transportation biofuels. The recovery facilities (WRRFs) into a supported by WRF, the Pacific North- results of the study were published in biocrude intermediate that can be west National Laboratory conducted an open access paper in the Journal of used to develop a variety of liquid a study investigating opportunities Environmental Management, and are fuels. A key advantage of this pro- to improve energy recovery at U.S. available at https://doi.org/10.1016/ cess is that wet organic materials can WRRFs to transform underutilized j.jenvman.2020.110852. be converted into oil, gas, or both municipal wastewater solids into a 24 October–December 2020 • Advances in Water Research Natural Assets Management of Natural Assets The condition and performance of natural assets are essential to a utility’s ability to cost effectively and reliably deliver safe drinking water and/or clean water and stormwater management services to its customers. By Bob Raucher, Raucher LLC; Kurt Vause, StreamlineAM LLC; and Maureen Hodgins, The Water Research Foundation N Aligning with Broader Utility Programs and Objectives atural assets—includingfor- to managing natural assets, which ested watersheds, aquifer sys- often are owned, managed, and/or tems, wetlands, and other nat- accessed by entities other than the THE AM FRAMEWORK AND guid- ural features—provide a wide range of utility. Asset Management Frame- ance provide a clear, step-by-step highly valuable services to water utili- work for Forested and Natural Assets process to help utility professionals ties, including contributions to source (Raucher et al. 2020), provides a systematically identify, assess, prior- water quality, moderating runoff and framework, and associated practical itize, and manage risks associated floods, and groundwater recharge. guidance, for how utility professionals with natural assets. The approach The loss or degradation of these natu- can apply the principles and tools of helps identify and assess potential ral assets can reduce the levels of ser- advanced asset management (AM) changes in the quality and quantity vice (LOS) provided, increase costs, practices to the natural systems that of natural systems and the associated and pose significant additional risks are critical to meeting a utility’s mis- services upon which a utility relies. It for a utility. sion and strategic objectives. Several also contains illustrative examples Because natural assets provide leading utilities have established AM and cross references to several exist- many important core services and practices for both built and natu- ing tools, frameworks, and standards associated beneficial values, they ral systems, and other utilities have related to source water hazards. By must be well managed. Like the begun the process of applying AM adopting an AM framework, the guid- built assets upon which a utility practices to their natural assets. While ance will help bring a utility’s natural depends, natural assets require sys- the report focuses on drinking water assets into better alignment with the tematic attention and management utilities, the same principles and prac- approach and strategic objectives to ensure that they deliver the types tices may also be applied to natural applied by many utilities to their of services that the utility relies on. assets supporting clean water, water built systems. For example, applying However, there are several challenges reuse, and stormwater agencies. an AM framework can place source Advances in Water Research • October–December 2020 25 Natural Assets water programs on equal footing deliver high-quality, safe, and afford- is recommended, starting with with pipe renewal and related risk able water to their customers. (1) an initial screening/reconnais- management, sustainability, and The AM framework for natural sance phase to make a stream- resilience enhancement programs. assets (Figure 1) is based on, and lined tour around the AM wheel; This commonality across utility activ- adapted from, the built asset version followed by (2) a more in-depth ities arises because these varied developed by American Water Works and focused application of the programs all typically apply a similar Association (Campanella et al. 2016), AM framework; and ultimately, process, with a focus on meeting the the U.S. Environmental Protection (3) engaging in a cycle of review utility’s strategic objectives in a sys- Agency, The Water Research Founda- and continuous improvement. tematic, risk-based, prioritized, and tion, and the Institute of Public Works For each step within the AM frame- cost-effective manner. Engineering Australia. Applying the AM Framework and Guidance work, Part 2 of the guidance provides The report consists of two parts: • both the technical basis and approach, Part 1 provides the AM Frame- as well as the process that will facili- work for Natural Assets, includ- tate implementation of the AM frame- THE FRAMEWORK AND GUIDANCE ing background information on work. Also included throughout are provided in Raucher et al. (2020) are natural assets and asset man- checklists, case study illustrations, intended for water utility profession- agement, as well as an overview clear definitions of key terms, and als and other individuals looking to offering a succinct introduction other practical information to help apply an AM approach to the natural to the concepts and content, users apply the AM framework to the assets that provide critical services using a Q&A format. natural assets relevant to their utilities. and value to their utility. The report • Part 2 provides guidance for describes an AM framework and pro- applying the AM framework and vides practical step-by-step guid- associated practices to natural ance for how an AM approach may assets, with a series of chapters Key Services and Values Provided, and Risks Faced SUSTAINABILITY AND EFFICIENCY be applied in a pragmatic fashion to that each address a step in the require that water utilities recognize forested watersheds, wetlands, and multi-step AM process depicted and prudently manage all of their crit- other natural assets that support the in Figure 1. A practical, itera- ical assets—including natural capital— ability of water agencies to reliably tive implementation process as well as built infrastructure and the 2. Describe the Current State of Natural Assets • Which natural assetsare important for utility performance? • Who owns those natural assets? • What is the current condition of those assets? • Are there threats to the future conditions of those assets? 7. Sustain Naural Asset Management • How to promote continuous improvement? • How to practice effective communication? 6. Create a Long-Term Funding Strategy • Can the utility capture spending on natural assets through rates? • Can external funds be leveraged through partnerships? • Can investments be made through the capital budget (e.g., debt financed)? 1. Tap Natural Asset Management Facilitators • Leadership commitment • Align with utility mission and strategic objectives • Integrate with knowledge management, training, and technology systems 5. Identify Capital Investment and Maintenance Opportunities • Are there feasible acquisition, conservation easement, or restoration options? • Are there long-term maintenance or enhancement options? • What are partnerships that might be required to execute these? 3. Determine Desired Level of Service (LOS) • For core business goals, how do natural assets affect performance? And what LOS from the asset is required to maintain or improve that performance? • For other strategic goals, what LOS will meet community expectations and regulatory requirements? For natural assets in particular, there is an interrelationship between condition assessment, LOS, and risk assessment. It may require an iterative approach for these three steps. 4. Assess Business Risks Associated With Natural Assets • How can natural assets degrade and fail to deliver desired levels of service? What is the likelihood of degredation? • What are the potential consequences of degraded LOS and the utility’s vulnerability to reduced performance? Source: Adapted from Campanella et al. 2016 Figure 1. The Natural Asset Management Wheel 26 October–December 2020 • Advances in Water Research Natural Assets utility’s human capital. The framework watershed, which may impose utility the project report, is a systematic and and guidance strengthen a water util- costs amounting to tens of millions comprehensive approach for: ity’s capacity to account for, invest in, of dollars to address resulting water 1. Creating a useful inventory and better manage its natural assets. quality impacts, reservoir sedimen- of assets, and assessing their The approach examines the chal- tation, and other damages. A utility lenges and opportunities for includ- supplied by a forested watershed 2. Defining the desired levels of ing natural assets alongside built needs to recognize the risks and service from the assets to meet infrastructure in how water utilities: consider how to reduce the likelihood utility strategic objectives; • condition; Develop and apply business and/or consequences of such a risk 3. Assessing the risk that the asset case evaluations, event. Risk management might thus may degrade, or fail, and thus not entail actively supporting efforts to deliver the target LOS required better manage forest lands in ways to meet the utility’s higher-order • Assess and manage risks, • Plan for robustness and resilience, that reduce the likelihood, intensity, • Value and leverage their assets, and spatial extent of potential wild- 4. Applying a risk management- strategic objectives; • Prioritize and manage capital fires, and that manage the sediment based approach to identifying improvement programs and and debris loads that result after such potential capital investments operation and management events. The objective for the utility is and/or maintenance expendi- budgets, to establish the level and quality of tures for at-risk assets, to miti- • Gain access to financing, the services to be provided by the gate risks to the asset’s ability • Recover costs through rates forested watershed, then monitor and to meet target LOS; • and other potential revenue manage performance in the face of sources, and the risks that apply to that asset. Communicate and collaborate with outside parties (including watershed partners). Natural assets, along with the util- 5. Conducting business case evaluations of the risk mitigation options to ensure they warrant Drawing on the Maturing Practice of AM investment of utility resources; 6. Implementing the selected risk THE GUIDANCE DRAWS FROM THE mitigation options; ity’s other key assets, are subject to rich field of AM as increasingly applied 7. Monitoring asset conditions and potential changes that pose busi- by water utilities to pipelines, treat- performance periodically to ness risks to the utility. For example, ment plants, and other built systems. ensure the risk mitigation invest- watersheds may be subject to devel- The objective is to draw on the same ment is performing as planned; opment, wildfires, flooding, and other principles and practices that are gain- events that would significantly alter ing maturity and broader sector-wide the level and/or quality of services application for built systems, and to tion approach if/as needed to that flow from those assets. Utilities apply them to natural assets so that ensure desired asset conditions must recognize these risks, and they a water utility can manage all of the are attained and performance need to apply the same principles and business risks of asset failures on is meeting target LOS (and practices of risk management as they equal footing. continuing the periodic review would for a built system (Figure 2). One example of a risk event is a and 8. Adjusting Asset management, as described risk mitiga- process to promote continuous and applied in the literature and in high-intensity wildfire in a forested the improvement). Because natural assets can be managed through capital investment and/or maintenance activities, the Identify Assets Assess Risk Develop Options to Mitigate Risk Create Long-Term Funding Plan principles and methods of AM can be applied to them. In other words, natural assets can be integrated into AM so that they are Figure 2. Building up to a long-term risk management and long-term funding plan Advances in Water Research • October–December 2020 managed alongside built 27 Natural Assets • MANGANESE assets to best meet a utility’s overarching business goals and strategic objectives. The framework and guidance offer a systematic, step-by-step approach for incorporating natural assets into an AM program, building on standard asset management Manganese Control (4749) E xpanding the understanding of the impacts of cold watertemperatures (i.e., below 15°C) on manganese (Mn) control across surface water biofiltration is critical. The objectives of Optimizing Biofiltration for Improved Manganese Control under Cold-Water Conditions were to (1) principles and practices. They also evaluate the primary causes of decreased dissolved Mn removal across sur- identify and address specific chal- face water biofilters during cold-water conditions, and (2) test optimization lenges of natural assets and those strategies for improving dissolved Mn removal across surface water biofilters that may require unique approaches. during cold-water conditions. The research assessed the impacts of media proj- characteristics, influent water quality, shutdowns, and empty bed contact ect was generously provided by Co-funding for this time on dissolved Mn removal across biofilters. Overall, this project confirmed the US Endowment for Forestry that there is a temperature threshold below which cold-water conditions and Communities. decrease dissolved Mn removal across surface water biofilters. It is recommended that utilities operating or considering biofiltration frequently monitor Mn concentrations across all treatment processes, and if Mn is observed in the filter influent, evaluate upstream control strategies and/or biofilter design References and operating strategies to improve Mn control. CAMPANELLA, K., C. Hyer, A. Vanrenterghem Raven, and K. Vause. 2016. Designing a Risk-Based Pipeline R&R Planning Program Using a Combination of Inspection and Analytical Approaches. In Proc. of American Water Works Association Annual Conference and Exposition, June 2016. AWWA. RAUCHER, R., K. Vause, M. Lorie, T. Helgeson, and J. Cassin. 2020. Asset Management Framework for Forested and Natural Assets. Project 4727. Denver, CO: The Water Research Foundation. Biofiltration pilot plant columns 28 October–December 2020 • Advances in Water Research Trace OrganicS • LEAD Trace Organic Compounds (4992) E valuating Analytical Methods for Detecting non-targeted analysis of unknown contaminants by both Unknown Chemicals in Recycled Water summarizes instrumental methods and bioassays, along with the advan- the current state-of-the-science for analytical meth- tages and limitations of each approach. The research report ods used to identify and measure unknown trace organic includes a research plan to evaluate the effectiveness of compounds (TOrCs) in recycled water. The researchers using these strategies for identifying unknown TOrCs, as propose an integrated framework that includes targeted well as a communications strategy that can be used by analysis of known contaminants, as well as semi- and regulators, managers, and the general public. Sample preparation methods for determination of TOrCs in aqueous matrices Method Target Analytes Solid phase extraction (SPE), activated carbon Non-polar, polar organics SPE, cation exchange, acidic conditions N-nitrosodimethylamine precursors SPE, hydrophobic/hydrophilic balance (Oasis HLB) Pharmaceuticals and personal care products, transformation products (oxybenzone) SPE, hydrophobic sorbent (e.g., C-18, XAD, HP-20) Non- and semi-polar organics Derivatization Polar, non-volatile organics, disinfection byproducts Purge and trap extraction Volatile organic compounds Azeotropic distillation Volatile, non-purgeable, water soluble organics Liquid-liquid extraction Non- and semi-polar organics Lead Service Line Identification (4693) D eveloping an accurateinven- approach has produced low accuracy and sufficiently sensitive to identify tory of lead service lines rates. Exploratory excavation can be lead pipes buried in soils of various (LSLs) is a challenge facing cost-prohibitive without an accurate types. Additionally, indirect screening many water utilities. The water sec- inventory of LSLs. Lead Service Line techniques used by utilities to gather tor has relied on indirect methods Identification Techniques reviewed information on the likely presence of that use historical records, such as the literature and industry practices LSLs were explored using case stud- tap cards, to develop inventories of to identify detection technologies ies to substantiate the usefulness of customer locations thought to have that are fast, portable, economical, promising approaches. LSLs. However, in some instances this user-friendly, minimally invasive, Advances in Water Research • October–December 2020 29 ? What topics are important to you Complete the Advances in Water Research survey and let us know what you want to read about! 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