Rocky Mountain Water - March/April 2023
March / April 2023 Issue of The Rocky Mountain Water Magazine. A joint publication of RMSAWWA and RMWEA. Open and start reading right away!
ROCKY MOUNTAIN SECTION of the AMERICAN WATER WORKS ASSOCIATION & ROCKY MOUNTAIN WATER ENVIRONMENT ASSOCIATION A JOINT PUBLICATION OF
COLORADO | NEW MEXICO | WYOMING
THE IMPORTANCE OF Resource Recovery
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COLORADO | NEW MEXICO | WYOMING
ON THE COVER: North Tenmile Creek winds underneath the shade of both Chief and Wichita Mountains ultimately feed water into Dillon Reservoir. Photo courtesy of Dena Egenhoff.
12 Research Advances the Understanding and Implementation of Resource Recovery
16 Recovering a Local Groundwater Source
from PFAS Contamination
ROCKY MOUNTAIN VIEW 6 RMWEA President Rocky Mountain Water Magazine 3-minute survey 8 RMSAWWA Chair SCIENCE, RESEARCH & TECHNOLOGY 22 Next Generation Resource Recovery
OPERATIONS 24 Managing Solids at New Mexico’s
32 The Debate To Focus On Risk And Resilience 34 Water Equity Is Becoming a Major Concern for Cities OF SPECIAL NOTE 36 Randy Gustafson Retires from Greeley Water and Sewer Department
Largest Surface Water Treatment Plant
MANAGEMENT PIPELINE 27 Creating a Positive Work/Home Integration: A New Mom in a Leadership Role HOT TOPICS 30 How WEF Is Integrating DEI into All We Do
INDEX OF ADVERTISERS 38 Advertisers Information
ROCKY MOUNTAIN WATER MARCH-APRIL 2023 | 5
ROCKY MOUNTAIN VIEW
FROM THE RMWEA President Hannah Fodor, P.E., PMP, DBIA
VOL. 55 NO. 78 MARCH-APRIL 2023
A JOINT PUBLICATION OF ROCKY MOUNTAIN SECTION of the AMERICAN WATER WORKS ASSOCIATION & ROCKY MOUNTAIN WATER ENVIRONMENT ASSOCIATION
S USTAINABILITY. THE UNITED Nations defines it as “meeting the needs of the present without compromising the ability of future generations to meet their own needs.” The United States EPA takes this definition further by directing the needs to survival and tying it to the environment: Everything that humans require for their survival and well-being depends, directly or indirectly, on the natural environment. The Oxford English Dictionary defines “sus tainable” as “capable of being maintained or continued at a certain rate or level.” As stewards of public health and the environment, we often hear these words, sometimes ad-nauseum , and I wonder if we lose sight of their true meaning. As water/ wastewater professionals, we are trained to make project-related decisions based on minimizing calculated negative long term impacts. We measure sustainability with metrics, such as energy consumption, operational and maintenance requirements, environmental emissions, and other factors that usually come with a price tag or permit limit. As RMWEA President, I’m learning that there is more to being sustainable , even environmentally sustainable , than what I learned as an environmental engineer. I’ve realized that the sustainability of our industry is far more complex than an economic analysis; the only way we can continue to positively impact the welfare of our society is through you, our members. Our industry’s focus on sustainability—
which by definition focuses on the future— actually starts with you, in the present. Sustainability is much like a Jenga tower: There are different pieces with unique and important characteristics, and when you start taking away the individual blocks, you risk the destruction of the entire tower. Most importantly, I’ve learned that to look at our future, we need to look at today. What does that mean for RMWEA? There is no doubt that our volunteers and members are dedicated to the future of public welfare, environment, and our industry. But, for this passionate group of individuals to successfully drive this shared vision, someone needs to be looking at them right now. That’s where our Executive Board comes in. Decisions we make today impact our volunteers in the near-term, which allows them to carry out their individual motivations and plans that will have this greater influence on our society and industry. I find it humbling, yet inspirational, to recognize that RMWEA’s Executive Board is here to focus on our volunteers and our leaders, so that they can continue growing as individuals and water-professionals, leading and delivering, and leaving that lasting impact on, not only the environment and public health, but others who will hopefully in-turn do the same. I encourage everyone to reach out to me to help us identify how the Board can provide even more support to enable you to keep going, now and in the future. After all, this is where I find my definition of sustainability.
Publications Committee Chair LACEY WILLIAMS email@example.com Editor Position Open Reviewers SERENA HENDON firstname.lastname@example.org ANGELA KANA-VEYDOVEC email@example.com Management Pipeline BLAIR CORNING firstname.lastname@example.org RMSAWWA Communications Committee DENA EGENHOFF, Co-Chair email@example.com RORY FRANKLIN, Co-Chair firstname.lastname@example.org ERIN ROGERS, eNewsletter Editor email@example.com RMWEA Communications Committee KERRY MAJOR, Chair firstname.lastname@example.org BRENDA VARNER, eNewsletter Editor email@example.com JORI NELSON, eNewsletter Editor firstname.lastname@example.org NATALIE COOK, eNewsletter Reviewer email@example.com Contribute to Rocky Mountain Water Rocky Mountain Water magazine is open to contributions from section members, water and wastewater utilities in Colorado, New Mexico and Wyoming, as well as consultants, engineers, and product manufacturers who have an interest in the regional water industry. Topics of interest include general regional coverage of the water and wastewater industry, science research and technology, utility operations, activities and accomplishments of individual committees, and other hot topics in the water and wastewater industry.
Hannah Fodor, P.E., PMP, DBIA, is the 2022-2023 President of RMWEA. She is a licensed professional engineer in Colorado and Nevada, a Project Management Professional (PMP), and a Designated Design Build Professional by the Design-Build Institute of America (DBIA). When she is not playing in the mountains, Hannah works as an owner’s representative/advisor in Carollo Engineer’s Utility Advisory Services and can be reached at firstname.lastname@example.org or president@RMWEA.org.
PLEASE HELP US take the Rocky Mountain Water Magazine to the next level by providing your input on this 3-minute survey. Results will help ensure we are serving our members‘ needs with the best possible content and delivery format. Survey closes May 1.
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ROCKY MOUNTAIN VIEW
FROM THE RMSAWWA Chair Rochelle Larson, P.E.
Meet the RMSAWWA Team! T HE SECTION’S EXECUTIVE DIRECTOR is Devon Buckels . In this role, Devon interfaces with the Board of Trustees to guide and implement the work of the Sec tion and serves as CEO, running the business of the Section. Devon has public, private and non-profit sector experience working for healthy and sustainable communities, highlighting the relationship between the built environment and public and ecological health. Devon is a Colorado native. She has a master’s degree in Urban and Regional Planning from the University of Colorado at Denver and a Certification in Sustainabil ity Leadership and Implementation from the Daniels College of Business. Erin Rogers Ridolfo was recently promoted to Membership Operations Manager. Erin leads member services, both support and recruit ment, and manages operations important to the execution of programs and day to day office functionality. She focuses on attracting new members and better engaging with our existing members. Erin has a broad range of experience supporting diverse nonprofit orga nizations. She particularly loves learning and teaching technology programs and applica tions. Erin grew up in Minnesota, where she received a bachelor’s degree from the Uni versity of Minnesota-Duluth. Erin also has a
master’s degree from the University of Denver in international studies and policy analysis. The newest staff member is Event and Administrative Coordinator Jenna Cowie. Before joining RMSAWWA, Jenna worked as a Faculty Assistant at Harvard Law School supporting faculty members and programs with a wide range of administrative and event coordination needs. Jenna also has prior experience as a middle school Language Arts teacher in Colorado. She grew up in Longmont, Colorado, and holds a bachelor’s degree in literature and a master’s degree in teaching from Fairleigh Dickinson University in New Jersey. She recently completed a mas ter’s degree in sustainability at the Harvard University Extension School.
Rocky Mountain Water magazine is published six times a year for the Rocky Mountain Section of AWWA and WEA . Publication of any article/comment herein does not constitute an endorsement by RMSAWWA, RMWEA, or the staff of Rocky Mountain Water for products or services. publication months : Jan.-Feb., Mar.-Apr., May June, July-Aug., Sept.-Oct., and Nov.-Dec. deadlines : Ten weeks before publication date. submissions : Rocky Mountain Water doesn’t consider unsolicited submissions. 2023 Editorial Calendar jan - feb : Collection and Distribution mar - apr : Resource Recovery may - june : Effective Utility Management july - aug : One Water sept - oct : Innovation and Technology nov - dec : Process and Treatment Rocky Mountain Water is looking for interesting and innovative projects to share with readers. Contact DENA EGENHOFF at dena.egenhoff@ greeleygov.com, or RORY FRANKLIN at email@example.com to share your ideas. Advertising For information on advertising opportunities, please contact KATHLEEN PISHOTTA at firstname.lastname@example.org or 352.371.4933. Published By APOGEE PUBLICATIONS 6528 Greenleaf Ave., Ste. 219 • Whittier, CA 90601 562.698.3424 • apogeepublications.com
Left to right: Jenna Cowie, Devon Buckels, Erin Rogers Ridolfo
New Committees/Task Force for 2022-2023 Small Systems Committee Is Back
RMS is happy to announce that it has a Small Systems Committee again. Please reach out to commit tee Chair Scott Price at email@example.com if you’re interested in participating. Bipartisan Infrastructure Law (BIL) Task Force RMSAWWA created a new Task Force in recognition of the significant opportunity presented to the water sector by the Infrastructure Investment & Jobs Act, otherwise known as the Bipartisan Infra structure Law (BIL). The Task Force’s primary responsibility is to track federal BIL funding as it is made available to the states and other receiving entities. Task Force members will maintain com munication with the CDPHE SRF office and other funding administrators, and work with Section staff for a coordinated dissemination of that information to our members. Task Force activities will include preparing and running new trainings and coordinating access to existing training sessions covering related BIL topics. This Task Force is planned to be active for five-years, consistent with the time frame for the BIL funding. For more information contact Task Force Chair Paniz Miesen at firstname.lastname@example.org. Resilience and Risk Committee The purpose of the Resilience and Risk Committee is to provide subject matter advice to RMSAWWA about important issues related to climate change risk and system resiliency assessment, emer gency preparedness, resilience, and adaptive management planning to mitigate and adapt to risk, and inform the Section’s training, events, and advocacy work. The committee aims to facilitate
NICOLE MILLMAN-FALK, editor AUDE CABALDON, art director
©Apogee Publications 2023 All rights reserved. The contents of this publication may not be reproduced by any means, in whole or in part, without the prior written consent of the publisher.
Continued on page 10
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ROCKY MOUNTAIN VIEW
RMSAWWA Chair , Continued from page 8
the exchange of knowledge on these topics. The goal is to build awareness and understand ing so that water users, regulators and elected officials make informed decision on climate change adaptation and mitigation, system resiliency, and emergency preparedness measures to manage risks affecting water sources and systems. For more information contact Committee Chair Steve Conrad at email@example.com.
New Mexico Water Workshop Albuquerque, New Mexico, April 2023 ACE Toronto , June 2023 Rocky Mountain Water Conference Loveland, Colorado , September 2023 Western Colorado Water & Wastewater Conference Grand Junction, Colorado, October 2023
New RMS Committee Chairs for 2022-2023
CHAIR OR CO-CHAIRS EMPLOYER
Bipartisan Infrastructure Bill Task Force Paniz Miesen
Colorado Water Utility Council
City of Aurora
Security Water and Sanitation District
City of Greeley
Rochelle Larson, P.E., is the 2022-2023 Chair of RMSAWWA. She is a Principal Engineer for the Albuquerque Bernalillo County Water Utility Authority, managing projects related to surface water, drinking water, waste¬water, stormwater, and groundwater. She has worked as an environmental engineer for nearly 14 years and received her bachelor’s degree in mechanical engineering from Arizona State University and a master’s degree in civil engineering from the University of New Mexico. Contact her at 505.289.3264 or firstname.lastname@example.org.
City of Westminster
City of Greeley
City of Longmont
Snake River Water District
City of Westminster
Autodesk / Innovyze
Continued on page 12
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RESEARCH ADVANCES THE Understanding and Implementation of RESOURCE RECOVERY
By Ashwin Dhanasekar, Stephanie Fevig, Alyse Greenberg, Jeff Moeller, Lola Olabode, and Harry Zhang
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W ASTEWATER CONTAINS ABUNDANT RESOURCES that can be recovered and utilized at, and beyond, water resource recovery facilities (WRRFs). An increasing number of projects use wastewater to heat and cool buildings, reducing energy consumption and fossil fuel usage. Other water- energy-waste tech nologies are being developed and adopted for production of high quality biosolids. These technologies have tremendous potential for growth as an increased understanding of the risks and costs of climate change expands the market for decarbonization and sustainability strategies.The Water Research Foundation (WRF) has sponsored exten sive research on recovering resources, such as biosolids and energy, from wastewater.
of soil amendments; conducted surveys to assess marketing strategies; and tested the ability of social media to build and engage a community of HQB biosolids producers, users, and supporters. The primary obstacle to expanding the use of biosolids nationwide is nuisance odor complaints where biosolids have been land-applied, as is a common practice in the Rocky Mountain region. While biosolids odor potential is influ enced by a wide range of wastewater characteristics and treatment param eters, several key relationships were identified: • Odor detection threshold (DT) values were statistically different based on the dewatering method. • Solids processed by advanced methods (e.g., pasteurization, chemical oxidation) were less odorous than solids subjected to conventional anaerobic digestion. • Biosolids blended with wood products had lower odor DT than unblended products. • An exceptionally high iron content appeared to be causally related to low odor DT. If there is a high ratio of iron in relation to sulfur, low odor is promoted. • While odor reduction strategies may involve costly advanced solids treatment processes, blending with wood products and curing post processing methods were found to reduce odors and/or increase the perception of pleasantness.
HIGH-QUALITY BIOSOLIDS Beneficial use of biosolids is a crucial element of recovering resources from wastewater. Effective recovery of value from biosolids involves gaining access to high-value markets, which are generally not accessible when only meeting the Class A/exceptional quality regulatory requirements. WRF project 4823, High Quality Biosolids from Wastewater, sought to define high quality biosolids (HQB) criteria, create products plate that WR R F s can use to characterize local high value fertilizer and amendment markets. The researchers evaluated HQB-derived products for parameters that charac terize human olfactory response to odor, as well as physical and chemical parameters that may influence perceptions of biosolids quality; demonstrated the use of HQB by conducting laboratory analysis that potential customers value, and develop a market ing tem
Photo and wheel graphic courtesy of the Water Research Foundation.
ROCKY MOUNTAIN WATER MARCH-APRIL 2023 | 13
ering STEU as an alternative approach. One challenge MWR faced was the lack of legal frameworks related to STEU; due to this, it might take a long time to negotiate a contract. MWR successfully navigated this by building flexibility into its contract to speed up the process. WRRFs and municipalities own sewer infrastructure and bear responsibility for its reliable operation. They must make sure the modifications allowing build ings to utilize wastewater for heat recov ery will not affect the service levels they provide.Therefore, MWR also supported its project financially by providing $10M towards the pipe upgrade and building a new odor control station. The project found that STEU implementa tion varies widely in application, design, and system capacity, demonstrating a degree of flexibility. It also remains an unorthodox approach, and many existing implementations came about because an
opportunity presented itself, rather than STEU coming up as a standard option. Reducing greenhouse gas emissions is becoming a higher priority due to climate change and mandates imposed by regula tors, and STEU will have a bigger role to play by becoming a standard method to New technologies and approaches are emerging to advance resource recovery. One example is the project Data-Driven Process Control for Maximizing Resource Efficiency (5141). The goals of this proj ect are to (1) develop and demonstrate data-driven process controls in full-scale facilities for five promising WRRF appli cations (i.e., process technologies) that provide whole plant approaches and offer substantial energy and resource recov ery benefits; and (2) create a toolbox and implementation guidance for data-driven process control approaches for accelerated offset energy consumption. LOOKING FORWARD
SEWAGE THERMAL ENERGY USE WRF project 4843, Integrating Sewage Thermal Energy Use (STEU) and Other Emerging Water-Energy-Waste Technolo gies into Decentralized/Distributed Systems , reviewed projects where energy derived from wastewater is successfully utilized beyond the premises of WRRFs, with a focus on STEU. This study showed how thermal energy from wastewater can be beneficially used, increasing the adoption of decentralized and distributed waste water energy utilization. Among the projects studied, one that stood out was from Metro Water Recov ery (MWR) in Denver, CO. MWR is required to keep its effluent tempera ture ≤ 12° C from December to Febru ary, which is 12° C below the threshold established for the rest of the year. Implementing conventional technolo gies to achieve this temperature drop is very costly and wasteful. MWR is consid
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adoption at WRRFs. The project integrates advancements in next-generation sensors and machine learning to bridge the gap between theoretical and full-scale process performance to better achieve treatment and resource recovery goals. Another ongoing project, Acid+ Diges tion (5108), aims to optimize acid gas (AG) digestion of wastewater biosolids and build on existing AG processes to develop a novel advanced digestion pro cess: Acid+ Digestion. Acid+ Digestion would enable WRRFs to increase digester capacity; enhance recovery of nutrients as struvite; protect digestion, dewatering, and centrate handling from struvite foul ing; and reduce biosolids phosphorus. Resource recovery will continue to be an important research topic for WRF and the water sector into the future as we seek to address climate change and many other societal challenges.
Jeff Moeller is a research unit leader at WRF, directing one of three research units at the organization. Jeff has over 25 years of experience leading
Ashwin Dhanasekar is a research program manager at The Water Research Foundation (WRF), where he leads WRF’s research on energy efficiency and
research on wastewater treatment, stormwater, decentralized systems, and integrated water management.
optimization. His additional areas of expertise include biosolids, microplastics and intelligent water systems. He can be reached at adhanas email@example.com or 303.734.3423.
Lola Olabode is a research pro gram manager at WRF, where she leads WRF’s research on constituents of emerging concern, microplastics, and receiving water
Stephanie Fevig is a research program manager at WRF, where she leads WRF’s research on nutrient treatment and source separated organics. Her
linkages in water quality. Her additional areas of expertise include public health, pathogens, and nutrients.
additional areas of expertise include waste water treatment, anaerobic digestion, resource recovery, and biosolids.
Harry Zhang is a research pro gram manager at WRF, where he leads WRF’s research on sustainable integrated water management and stormwater. His
Alyse Greenberg is a content manager at WRF, serving as editor of WRF’s quarterly magazine and providing writing and editing support to
additional areas of expertise include watershed management, stream restoration, decentralized systems, and climate change.
ROCKY MOUNTAIN WATER MARCH-APRIL 2023 | 15
RECOVERING A LOCAL GROUNDWATER SOURCE
Ice Pigging process samples
Ice Pig generation trailer.
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FROM CONTAMINATION PFAS P ER- AND POLYFLUOROALKYL SUBSTANCES HAVE QUICKLY BECOME ONE OF THE WATER INDUSTRY’S BIGGEST CONCERNS. PFAS, THE ACRONYM CHOSEN TO ENCAPSULATE THE 12,000 VARIETIES OF THESE MAN-MADE COMPOUNDS, ARE CONSIDERED FOREVER CHEMICALS DUE TO THEIR STRONG CARBON-FLUORINE BOND. With their ability to accumulate over time in the environment and in the bodies of animals and people, remediating PFAS in drinking water has become an overwhelming task for small and large utilities alike to maintain consumer confidence, despite the lack of regulation and enforcement on the chemicals. Page 16-17 background photo: Fire hydrant manifold and 20,000 gallon Frac tank. By Brandon Bernard
There are hundreds of water utilities across the country struggling with how to handle PFAS-contaminated waters. The story is no different here in the State of Colorado. In Jan uary 2016, water providers serving a population of 10,000 or more were ringing in the new year with updated results from EPA’s Unregulated Contaminant Monitoring Rule # 3 (UCMR3). Six of the 30 emerging contaminants of concern, for which water providers were required to monitor, were the relatively unknown perfluorinated compounds (PFAS). Of the thousands of water providers in Colorado, only four utilities discovered PFAS in their groundwater at levels close to and/or above the EPA’s established Health Advisories Levels (HAL) in effect at the time for two of the six PFAS listed in the UCMR3. These were a HAL of 400 parts per trillion (ppt) for Perfluoro-octanoic Acid (PFOA) and 200 ppt for Perfluoro-octane sulfonate acid (PFOS). Security Water District, located on Colorado’s front range, had levels of PFAS in concentrations higher than the other three utili ties who detected it. A HAL is developed when a chemical is found in drinking water and no regulatory standard, or
By Mary Dawson On May 19, 2016, the EPA further lowered the HAL’s for PFOA and PFOS to a combined concentration of 70 parts per trillion (ppt). With PFOS alone achieving concentra tions of 70 ppt and higher, Security Water District, Colorado Springs, immediately issued voluntary water restrictions to curb demand and began construction of an emergency water connection to Colorado Springs Utilities distribution system. The district was able to shut down its groundwater wells in September 2016, and these wells remained dor mant for another four years while its leadership worked to address the newly evolving concern. It was determined that Security Water District’s ground water source was contaminated due to the use of Aqueous maximum contaminant level, exists for the chemical. The HAL concentration of a chemical in drinking water is a value that below which, based on the available data, is vir tually certain not to cause adverse human health effects if consumed over a lifetime. This was not how the local media portrayed the findings of these chemicals in 2016.
ROCKY MOUNTAIN WATER MARCH-APRIL 2023 | 17
piloting over a six-month period in 2016 to review breakthrough curves for the six PFAS compounds in the UCMR3, with a focus on PFOA and PFOS. The pilot’s media consisted of one granulated activated carbon (GAC) and four ion exchange resins (IX). GAC was ruled out after approximately 20,000 bed volumes due to early breakthrough of PFOA (Figure 4), as well as nitrate sluffing. Both PFAS and nitrate adsorb to the GAC and are thus removed from the effluent flow. However, it was discovered upon shut down and startup of the treatment flow that nitrate would sluff off to levels higher than the maximum contaminant level (MCL) of 100 mg/L (Figure 3).
Fire Fighting Foam at a nearby Air Force base. The Air Force earmarked $4.3 mil lion to address contaminated wells in the four water utilities, as well as privately owned wells, mobile home parks, and a local farm. It was quickly recognized by local leadership that the budget to rectify this situation would be much more than $4.3 million. In October 2017, leadership from the local water utilities were able to procure a meeting at the Pentagon with the Air Force’s Deputy Assistant Secretary to address the magnitude of
the contamination and the concern over the consumer confidence of over 60,000 people (Figure 1). This meeting, as well as others with Colorado legislators at the country’s Capitol, helped local water utilities begin engagement with the Air Force Civil Engineering Center (AFCEC) to determine real time solutions to aid these communities along Colorado’s Front Range (Figure 2). The engineering firm JDS-Hydro, a Division of RESPEC, performed water
Figure 2: Security Water District and local leadership with Senator Michael Bennet.
The four IX resins piloted consisted of three gel resins and one macroporous. Of the four, two gel resins and the one
Figure 1: Security Water District and neighboring utilities in D.C.
Figure 4: Breakthrough curves on GAC and IX resin.
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Figure 3 Security Water District and local leadership with Senator Michael Bennet.
bed volumes of water, or 840,000,000 gallons. This amount of treatment is also conservative as the effluent concentra tions from the lead vessel were only 18.1 ppt for PFOA. PFOS was non-detect through 265,000 bed volumes. The Security Water District’s Security Area Mitigation System (SAMS) facility was designed with four treatment trains, in lead/lag formation, as well as 565 cubic feet of resin per vessel. The maximum capacity of the SAMS facility is 6,800
gallons per minute, or approximately 9.8 million gallons per day. As with any water treatment plant, there are unknown obstacles that may hinder the startup and shakedown of the facility. In the case of Security Water District, ion exchange resin beads were accidentally introduced to the effluent pipework of the facility. A 3,000 foot long, 24-inch diameter ductile iron pipe acts as a chlorine contact vessel as the water makes its way to the ground
macroporous performed well after 100,000 bed volumes (Figure 4). Based on the pilot testing and the experience of others, Security Water District decided to move forward with the macroporous resin for its full-scale treatment facil ity based on its performance, cost, and chemical makeup. Unlike microporous resin, gel resin beads do not have a pore structure at their core. The bead relies on water diffusion for transport of the ions into the bead. Conversely, macro porous resin beads have pores that aid transport of water and ions through the bead to provide more surface area for diffusion of ions. The macroporous resin chosen by Security Water District is also a Strong Base Anion resin, mean ing it has an excellent physical and chemical stability, which is capable of exchanging the different ions under a wide range of pH value. Security Water District is one of the first municipalities in the United States to implement full scale treatment of PFAS contaminated groundwater and cur rently operates Colorado’s largest ion exchange mitigation facility for PFAS. Previous breakthrough curves for full scale treatment determined 424 cubic feet of strong base ion exchange resin could mitigate PFOA and PFOS from 265,000
Figure 4: Breakthrough curves on GAC and IX resin.
ROCKY MOUNTAIN WATER MARCH-APRIL 2023 | 19
was successful, and Security Water District has been operating the SAMS facility 24 hours a day, seven days a week since May 16, 2022.
every 1,000 feet, while two 2-inch tap saddles were installed in between the fire hydrants every 500 feet. In addi tion, two frac tanks capable of holding 20,000 gallons were strategically placed to facilitate the weeklong process. Every day over the course of six, Securi ty Water District personnel, along with American Pipeline Solutions, worked together to introduce 3,000 gallons of ice slurry into the 24-inch pipeline and proceed to move the slurry 500 feet and into the 20,000-gallon Frac tank at a rate of 1,100 gallons per minute. During this process, District staff monitored for temperature and total dissolved solids to ensure the pipeline was completely void of the ice pig, and hopefully resin, when complete. American Pipeline Solutions then gen erated the ice overnight to repeat the process the next day until all 3,000 feet of pipeline were pigged. The gamble
water storage tanks, prior to being delivered to the customer. Hundreds of thousands of gallons of flushing could not scour the pipe enough to displace the resin beads. Security Water District collaborated with the Colorado Depart ment of Health and Environment to investigate the possibility of ice pig ging. Historically, pigging has referred to the practice of using mechanical devices known as pigs to remove various type of debris in pipelines. Ice pigging has slowly developed and is considered the best available technique for many pipe cleaning situations as it radically decreases the time involved and enhances the quality of clean. There was only one company in the United States that could perform ice pigging, making planning, schedul ing, and implementing the process in a 3,000-foot pipeline challenging. Two fire hydrants had to be installed
Brandon is Security Water District’s Operations Manager for Water and Wastewater. He has been in the water Bernard
and wastewater industries for 20 years and holds multiple certifications in water treatment, water distribution, wastewater collections, and wastewater treatment. Bernard has a bachelor of science in tech nical theatre from Northwest Missouri State University and has completed a Certificate of Utility Management from Willamette University, the Certified Public Manager Program through the University of Denver, and a master’s cer tification in Applied Global Stability for Water Resources.
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SCIENCE, RESEARCH & TECHNOLOGY
Next Generation Resource Recovery By Dustin Craig, P.E., and Ben Mosher, P.E., CDM
Resource Recovery at Des Moines WRA. Photo courtesy CDM Smith.
T HE COST OF ENERGY AT A WATER RECLAMATION facility (WRF) can represent as much as 30% of the facility’s operating budget. Increasing electric and natural gas rates, combined with the increased energy demands required for more stringent treatment, contribute to the escalating cost of treatment operations. At the same time, there is a growing interest in using renewable energy and reducing greenhouse gases. One solution is resource recovery, which provides major oppor tunities for improvements to the nation’s water reclamation industry. Viewing a WRF as a valuable source of water, biosolids, energy, and nutrients will help in developing integrated, sustain able solutions. Water can be reclaimed and reused; wastewater biosolids can be converted into biogas; biogas can be fed to a cogeneration system, or they can be processed into renewable natural gas. Harnessing energy from biosolids at WRFs reduces greenhouse gases and can produce enough electricity to power thousands of homes. Several WRFs are leading the way in this effort. The experiences of two of them are highlighted below. The Water Reclamation Authority (WRA), located in Des Moines, Iowa, has one of the largest co-digestion programs in the country. Co-digestion refers to the anaerobic digestion of multiple organic wastes in one digester to increase the methane production from these organic feedstocks. The WRA operates a regional co-digestion facility, receiving significant volumes of imported organic wastes from local food processing, agricultural, and other high strength waste sources. CDM Smith provided design and construction services for the upgrade of the WRA’s six anaerobic digesters, modifications to the organic waste receiving station, and the installation of a new biogas treatment system that converts biogas into renewable natural gas (RNG). The WRA recognized a huge opportunity to sell its biogas, with the goal of offsetting opera tion and maintenance costs and potentially generating net revenue for WRA and its member communities, resulting in positive impacts on sewer rates. CDM Smith led the design of a biogas conditioning and injection system to convert up to 2,250 standard cubic feet per minute (scfm) of biogas produced at the facility into a high-quality RNG that is injected into the Co-Digestion to Renewable Natural Gas Pipeline Injection
MidAmerican Energy Company’s local natural gas pipeline. The Des Moines WRA project demonstrates how the recovery of a waste resource is environmentally resilient, economical for its ratepayers, and supports WRA’s sustainability initiatives and financial goals. The project produces the equivalent daily natu ral gas use of 5,000 typical households, reduces greenhouse gas emissions, and provides significant gross annual revenue which helps offset operations and maintenance costs at the facility Organics to Energy Project at Greater Lawrence Sanitary District The Greater Lawrence Sanitary District (GLSD) in North Ando ver, Massachusetts, recently developed and implemented an innovative project that captures the core principles of sustain ability and resiliency. The GLSD Organics to Energy project combines two materials that have traditionally been viewed as waste products—food waste and wastewater sludge—and con verts them to a clean energy source. GLSD operates one of the few anaerobic digestion facilities in New England where digester gas is used as the primary fuel for a thermal biosolids drying operation and for building and process heat. GLSD recognized that bans on the disposal of food waste presented an opportunity to further its goal of net zero energy for its treatment facility. GLSD determined these organics can be used, along with biosolids, as a feedstock for generation of biogas in their anaerobic digestion facility and increase generation of clean energy. GLSD expanded the existing digestion system to allow for co-digestion of biosolids and food waste and added a new biogas-fired cogeneration system to produce renewable energy for use at the facility. The most obvious benefit of the project to GLSD and its rate payers is the savings resulting from less electricity purchased from the grid. The cogeneration system, using biogas as its pri mary fuel, has been able to fully meet the power needs of the treatment facility, as well as offset the power consumption at the Riverside Pump Station (RSPS) through a net metering arrange ment. This will result in an annual cost savings of more than $2.5 million based on current energy prices. Summary The Des Moines WRA and the GLSD organics to energy projects provide long-term net economic benefits to their member
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SCIENCE, RESEARCH & TECHNOLOGY
ty, globalization, urbanization, and increased per capita resource consumption require us to not just refurbish our existing infra structure, but to rebuild infrastructure in a smarter, more resilient way. These projects serve as a model for a smarter, more resilient approach to infrastructure needed to meet the challenges of the next several decades. Dustin Craig, P.E., CDM, is an Environmental Engi neer at CDM Smith’s Kansas City, Missouri, office, serving as a Bioenergy Practice Leader. Craig has extensive experience in wastewater solids handling processes and bioenergy utilization in all project phases, including conceptual planning, design, and construction of these facili ties in both the municipal and industrial markets nationwide.
GLSD Organics to Energy Facility. Photo courtesy CDM Smith.
communities. These benefits will likely increase over time as the cost of traditional energy sources escalates and the industry moves to renewable energy sources. However, while the cost savings are the easiest benefits to quantify, there are several additional project benefits to the facilities and their regions. These benefits include protecting against future increases in energy costs, greater facility resiliency and operational flexibility, greater system reliability, beneficial use of organic material that was previously thought of as waste, and the significant reduction in net greenhouse emissions. The combined effects of climate change, water and energy scarci
Ben Mosher P.E., CDM, is a Vice President at CDM Smith and is based in the Manchester, New Hamp shire, office. Mosher is a registered Professional Engi neer in multiple states, a Board Certified Environmen tal Engineer, Envision Sustainability Professional, and
a Certified Project Management Professional. He has managed a wide variety of projects, ranging from large-scale municipal wastewater treatment facility upgrades to the design of biosolids processing, fertil izer production, and energy recovery facilities.
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Managing Solids at New Mexico’s Largest Surface Water Treatment Plant By Cassia Sanchez, P.E., Damian Luna, P.E., and Charlie Leder, P.E.
Figure 1. Raw water intake on the Rio Grande; Photo courtesy of Google Earth.
M ANAGING SOLIDS AT THE ALBUQUERQUE Bernalillo County Water Utility Authority’s San Juan Chama Water Treatment Plant (SJCWTP) can, indeed, be complicated when one considers seasonal changes in raw water turbidity and sediment loads, monthly targets for water production, and constraints on raw water diversions. Nonetheless, the Water Authority’s staff at SJCWTP has developed and executed an effective strategy for managing solids that accumulate in the treatment process. With favorable river flow conditions, this 84 million gallons per day (MGD) capacity treatment plant can supply as much as 70% of all water used by Water Authority customers each year, which means there can be a lot of solids to manage! The first location in the treatment process at which solids are managed is at the raw water intake on the Rio Grande (Figure 1). The intake structure features a bar screen/trash rack, flow control gates, and concrete structures for directing flow to a pair of fish screens. As the bar screen collects floating materials, flow towards the fish screens becomes reduced. Operations staff periodically rake off the accumulated material to restore intake capacity. The Water Authority is now installing a mechanical screen cleaner that will automate intake debris removal. This new device will be especially helpful for cleaning the intake during spring runoff periods when debris loads can change suddenly. Downstream of the bar racks are fine mesh screens (0.069-inch openings) that keep fish and their eggs from entering the twin 60-inch pipes
that feed the nearby raw water pump station. Figure 2 on the next page shows the traveling brush mechanism used to keep the screen panels clean. River sediments accumulate in the channels between the bar racks and the fish screens. Once the sediment level exceeds six inches, operators isolate the channel, drain it with a trash pump, and then use a front-end loader and a skid steer loader to remove the sediment.This process may need to be performed two to four times a week during high river turbidity periods and tapering off to just twice a month during low turbidity periods. The extracted material is placed back in the river. An estimated 6,400 cubic yards (CY) of sediment is removed from the river intake structure each year. The next step for SJCWTP solids management is at the end of the seven-mile, 72-inch diameter pipeline that conveys water from the raw water pump station to the SJCWTP campus. Raw water is first directed into two five-million-gallon (MG) capacity concrete basins that provide gravity settling for grit and silt. These basins are cleaned annually using a front-end loader and a pair of 20 CY dump trucks that haul the material to one of four 8,000 CY capacity concrete drying beds at the plant. It takes a three-person crew between four to eight weeks to fully clean a basin and in the process remove between 3,200 to 6,400 CY of sediment. Figure 3 on page 26 provides an aerial view of these two basins and adjoining settled water ponds that provide one to two days storage before water enters the plant.These storage
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ponds also receive all filter backwash and other side streams from water treatment operations. The next step for water treatment solids management focuses on ferric hydroxide sludge produced by the flocculation sedimentation process. The iron sludge from this process is first gravity thickened to 2 to 4% total solids (TS) and then transferred to a 500,000-gallon storage tank equipped with four turbine mixers to keep the sludge homogenized. The sludge is then managed in one of three ways. The first choice is to discharge it to the Water Authority’s collection system. Full-scale testing conducted between March 2018 and June 2019 showed that the iron content in this sludge provides an odor control benefit in the sewers by reducing the quantity of liquid ferric chloride that otherwise needs to be fed for odor control. Once arriving at the Water Authority’s Southside Water Reclamation Plant (SWRP), the iron sludge also helps reduce hydrogen sulfide levels in the plant’s anaerobic digester gas. Iron sludge discharges to the sewer are currently limited to 5,000 pounds per day of TS to prevent the sludge’s inert solids from upsetting the wastewater treatment process solids balance. Iron sludge discharges are controlled using a magnetic flow meter on the pump that discharges to the sewer together with an online total solids meter. Daily grab samples of iron sludge are analyzed for TS content to cross-check the online solids meter. The second choice for managing SJCWTP iron sludge is mechanical dewatering using screw presses. The Water Authority pilot tested this technology in 2019 and determined it was a much simpler process to operate compared to belt filter presses which had been used between 2012 and 2018 during periods of peak water production in summer. The permanent dewatering facility was commissioned in March 2021 and features two 1,350 pounds per hour (lbs/hr) capacity screw presses, a stirred bulk storage tank for liquid emulsion polymer, polymer make-up and feed units, progressive cavity pumps that control sludge feed to each press, and screw conveyors
Figure 2. Traveling Brush System for Fish Screen Cleaning. Screened water enters the raw water pump station forebay. Photo from Water Authority archives.
to transfer dewatered cake into a 20 CY truck parked outside the building that houses this equipment. Depending on thickener underflow concentration, each screw press can process between 25 to 120 gallons per minute of iron sludge and produce a dewatered cake measuring 25 to 27% TS. Screw press dewatering typically consumes 18 pounds of active liquid emulsion polymer per dry ton of solids treated. The polymer used is an NSF 60 certified 30% active cationic liquid emulsion that allows the screw press filtrate
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A front-end loader is used to periodically turn the material after it has partially dried to 15% TS to help speed further drying. The final step in managing SJCWTP solids is periodically removing fine silty material that settles in the storage ponds. Over the past 12 years of plant operations, an estimated 198,000 CY of sediment has collected in the two ponds. Through consultation with the NM Environment Department’s Solid Waste Bureau, the Water Authority determined these sediments won’t require disposal in a regulated landfill. Plans are being developed to hire a specialty contractor to extract the pond solids and haul them to a disposal site. Disposal options being considered include use as landfill cover at area landfills or possibly surface spreading on the site at which the Water Authority land applies wastewater biosolids. Reference 1. Leder, C.S., McLee, P., Salvas, S., Lipe, K., Johnson, K., & Romanowski, J. (2019). Odor Control Benefits of Water Treatment Plant Iron Hydroxide Sludge at the Albuquerque Bernalillo County Water Utility Authority’s Southside Water Reclamation Plant . WEFTEC 2019: Chicago, Illinois.
and wash water to be reincorporated into the water treatment process. Screw press cake is mixed with dried grit basin solids using a front-end loader at a volume ratio of 70% screw press cake/30% grit basin solids. The blended material is used by a local sanitary landfill as its daily cover material. At times when Rio Grande water turbidity exceeds 500 Nephelometric Turbidity Unit (NTU) for extended periods, the combination of sewer discharge and screw press dewatering may not keep up with the volume of iron sludge generated. In these instances, Plan C for managing iron sludge is to pump it into one of the four drying beds in which it will air dry over time. Figure 3. SJCWTP Grit Basins and adjacent Settled Water Ponds. Water first enters the long rectangular compartments where heavier river sands and silt settle. Photo courtesy of Google Earth.
Cassi Sanchez, P.E., is Chief Engineer for the Albu querque Bernalillo County Water Utility Author ity’s San Juan Chama Water Treatment Plant. She can be reached at firstname.lastname@example.org Damian Luna, P.E., is Principal Engineer for the Albuquerque Bernalillo County Water Util ity Authority’s San Juan Chama Water Treatment Plant and can be reached at email@example.com. Charlie Leder, P.E., serves as Manager of the Albu querque Bernalillo County Water Utility Author ity’s Plant Operations Division and can be reached at firstname.lastname@example.org.
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Creating a Positive Work/ Home Integration: A New Mom in a Leadership Role By Kacie Allard
A S THE DEPUTY DIRECTOR – BUSINESS SOLUTIONS for South Platte Renew, I oversee the team responsible for providing overall administrative support to the organization, including finance/procurement, communications, outreach and marketing, IT help desk support, and government relations. In 2021, I experienced
a life change with the birth of my first child. With this excitement came a wave of emotions and concern for how I would remain a dedicated professional and a devoted mother. Before motherhood, I often found myself working long hours and doing work on nights and weekends. However, when my son arrived, I knew these long workdays weren’t sustainable.
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43% 30% 90%
OF PARENTS FEEL 61% Overwhelming Stress
200% BETWEEN MEN + WOMEN
Parenting + Work Difficulty
Parenting + Work Difficulty
Being Stressed At Jobs
Burnout Gap Doubled
Being a working mom is stressful, and the statistics confirm the challenge. One study by My Perfect Resume reported that 43% of women and 30% of men are unable to give it their all at work because of the difficulties of balancing parenting and work. A survey by Bright Horizons reported 90% of parents as being stressed at their jobs, and 61% described that stress as overwhelming. Additionally, according to the 2021 Women in the Workplace Report, the burnout gap between men and women has nearly doubled since 2020. Before coming back from maternity leave, I wanted to make sure I had a plan to minimize burnout and make the most of my time at work and at home with my son. Here are a few steps that I took to create a more positive work/home integration.
Prioritize and then re-prioritize To commit to a schedule, I constantly prioritize and re-prioritize my workday and to-do list. At the beginning of every day, I assess my meeting schedule and to-do list. I identify priority meetings and prepare for them, then list the three most important tasks for the day, and do them first. This approach ensures I am ready to convene with others, meet essential deadlines, and allows me to feel accomplished when I sign off. It also reduces the risk of working on critical tasks at the end of the day, which could extend my workday.
Give yourself some grace I constantly give myself grace with the situation, especially
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