About

Frank Loge is a Professor and Vice Chair for Graduate Studies in the Department of Civil and Environmental Engineering at the University of California, Davis. His mission at the Center for Water-Energy Efficiency (CWEE) is to advance water management solutions that promote the integrated savings of water and energy resources. His work focuses on developing strategies, technologies, and policies aimed at achieving mutual benefits in water, energy, carbon, and cost savings. The center seeks to increase resource efficiency and resiliency amid changing regulatory and environmental conditions by disseminating research results to enhance public awareness, stakeholder engagement, and the widespread adoption of sustainable solutions. Professor Loge has received numerous awards and honors, including the 2015 and 2017 US Department of Energy Solar Decathlon Award, the 2013 Ray B. Krone Endowed Professorship, and the NSF Career Award in 2001. He has also been recognized through multiple People Prosperity and Planet (P3) Awards for student-led sustainability projects related to wastewater treatment. His research and leadership contribute significantly to advancing sustainable water management practices, with a focus on integrating water and energy resource efficiencies.

Research topics

• Political Science
• Economics
• Ecology
• Psychology
• Biology
• Environmental science
• Business
• Microeconomics
• Environmental resource management
• Geology
• Geography
• Natural resource economics
• Water resource management
• Environmental protection
• Engineering
• Environmental economics

Selected publications

• National-scale prediction of arsenic, fluoride and its co-occurrence in groundwater of Mexico: Implications for drinking-water

  Journal of Hazardous Materials · 2026-05-01

  article
  PublisherDOI

• Microalgal‐bacterial aggregates for wastewater treatment: Origins, challenges, and future directions

  Water Environment Research · 2025-02-01 · 15 citations

  reviewOpen accessSenior authorCorresponding

  Microalgal-bacterial aggregates are promising for wastewater treatment because they remove organic matter, nitrogen, and phosphorus while producing biomass that settles quickly. This review details the development of microalgal-bacterial aggregates, identifies key challenges, and proposes future research directions. While many studies have been performed in the laboratory with synthetic wastewater and artificial lighting, more research is needed to better understand how to form and sustain aggregates at larger scales with real wastewater and natural lighting. While it appears that microalgal-bacterial aggregates are unlikely to replace or augment conventional activated sludge, they have the potential to improve resource recovery in existing microalgae-based wastewater treatment processes (e.g., high-rate algal ponds). Alternatively, attached-growth bioreactors utilizing microalgal-bacterial consortia may be able to compete directly with conventional activated sludge while providing the benefits that microalgae offer, although additional research is needed. PRACTITIONER POINTS: More pilot and full-scale research on microalgal-bacterial processes is needed. Microalgae cultivation with short retention times is challenging. Attached-growth processes may allow for competitive footprint requirements.

  PublisherOA PDFDOI

• Evaluating sludge management strategies using wastewater treatment plant simulations and life cycle assessment

  Journal of Material Cycles and Waste Management · 2025-09-01 · 7 citations

  articleOpen access

  Abstract The goal of this study is to compare the environmental and energy performance of three sludge management scenarios at a wastewater treatment plant in Mexico, using process simulations and life cycle assessment (LCA) to assess energy use, environmental impacts, and costs. The functional unit is one cubic meter of treated influent wastewater, including sludge treatment and disposal. Screw press, thermal drying, and anaerobic digestion (AD) were assessed for energy use and environmental impacts, focusing on global warming potential, terrestrial acidification, freshwater eutrophication, and fossil resource scarcity. The Base Case scenario assumes a 50/50 distribution of wastewater flow between two biological treatment lines (anoxic/oxic and conventional activated sludge), with sludge equally treated by drying and screw pressing. The Best-Case scenario directs all flow to the anoxic/oxic line and treats all sludge through AD with electricity and heat recovery. Compared with the Base Case, the Best-Case scenario reduced energy use by 14%, corresponding to a specific energy savings of 0.04 kWh/m 3 , and achieved annual cost savings of 35,891 USD. The key challenges included limited data on sludge characteristics and disposal practices in Mexico, which required careful adaptation. LCA was enabled through process simulation, which provided site-specific inventory data despite limited regional reporting.

  PublisherOA PDFDOI

• Advancing groundwater quality predictions: Machine learning challenges and solutions

  The Science of The Total Environment · 2024-07-23 · 40 citations

  review
  PublisherDOI

• Economically Optimal Leak Management: Balancing Pressure Reduction, Energy Recovery, and Leak Detection and Repair

  Journal of Water Resources Planning and Management · 2024-06-03 · 7 citations

  articleOpen accessSenior author

  Maximizing the net economic benefits of leak management programs provides the most value to water utilities and their customers. Leak management programs with alternative objectives (e.g., to “break even” or to maximize leak reduction) are not necessarily the most efficient use of resources. Combining hydraulic modeling with principles of economics and using a real distribution system to provide a case study, we present a methodology for maximizing the net economic benefits of a leak management program consisting of leak detection and repair activities and pressure management interventions. The optimization results include recommended leak detection and repair intervals for individual district metered areas, optimal siting of both pressure reducing valves and pumps-as-turbines (PATs), and modifications to the distribution system’s connectivity to isolate high-pressure areas. The case study results indicate that 10% to 11% of the system’s current energy use can be recovered by PATs and that the avoided leakage over the study period is equivalent to 13% to 23% of the system’s current customer demand. While leak detection and repair and pressure management are more commonly considered independently, this analysis demonstrates the feasibility of including their interdependencies when optimizing a leak management program, resulting in more useful recommendations.

  PublisherDOI

• Data-driven models for groundwater nitrate contamination prediction: A nation-wide approach for Mexico

  2024-03-08

  preprintOpen accessSenior author

  Nitrate (NO3−-N) stands as one of the prevalent chemical contaminants in groundwater, posing potential repercussions on both the environment and public health. However, the monitoring of this parameter on a national scale is notably limited, especially in developing regions. To address this gap, we applied distinct machine learning (ML) algorithms (Extreme Gradient Boosting, Boosted Regression Trees, Random Forest, and Support Vector Machines) capable of quantifying/predicting NO3−-N concentrations in groundwater. These algorithms were validated through comprehensive application across Mexico. The models initially considered 68 covariates and identified significant predictors of NO3−-N concentration spanning from climate, geomorphology, soil, hydrogeology, and human factors. We achieved an outstanding performance with about 10 times less availability of information compared to previous large-scale assessments, and thus efficiently countered the challenge of limited data availability/monitoring stations. Our success can be attributed mainly to the implementation of the 'Support Points-based Split Approach' during pre-processing, which effectively transformed the limited national groundwater quality database into spatial points suitable for appropriate train/test datasets. Areas exhibiting NO3−-N concentrations exceeding the drinking water standard (>10 mg/L) were identified, notably in the north-central and northeast regions of the country, linked to agricultural and industrial activities. Individuals living in these regions face potential exposure to elevated NO3−-N levels in groundwater. These NO3−-N hotspots align with reported health implications such as gastric and colorectal cancer. This study not only showcases the potential of ML in data-scarce regions but also provides actionable insights for policy and management strategies.

  PublisherDOI

• A Metagenomic Study of Antibiotic Resistance Genes in a Hypereutrophic Subtropical Lake Contaminated by Anthropogenic Sources

  SSRN Electronic Journal · 2024-01-01 · 1 citations

  preprintOpen access
  PublisherDOI

• Cost-Effectiveness of Urban Water Demand Management Programs

  Journal of Water Resources Planning and Management · 2024-12-06 · 3 citations

  articleOpen accessSenior author

  During droughts, potable water agencies may need to increase supply or reduce demand. Water agencies have many options for water demand management (WDM), including low flow toilets, showerheads, faucet aerators, educational outreach, and more. Reduced water consumption may result in energy savings, both at the customer and utility level. In this study, we estimated household water, electricity, and natural gas and utility-wide energy savings using statistical modeling for four large water demand management programs implemented between 2014 and 2018 in California. These programs focused on single and multifamily retrofit programs. These retrospective analyses were performed using household-level data gathered from multiple water, electricity, and natural gas companies. We found detectable water savings in three of the four programs, no detectable electricity savings for any program, and detectable gas savings in only one program. The deemed estimates of water savings were generally inaccurate predictors of actual savings. All programs that reduced household water consumption also reduced system-wide electricity consumption. A benefit–cost analysis was performed for each program from the perspectives of three stakeholders: water utilities, households, and a regulatory authority responsible for greenhouse gas emissions (GHGs). Many of the program actions were not cost-effective for the participating utilities and households because of the low cost of water. For the WDM programs considered here cost-effective from the perspective of the water utilities, the opportunity cost of consuming an additional unit of water would have to exceed their observed variable production costs in 2020 by a factor of 3 to nearly 20, dependent on the utility. In settings with sufficiently severe drought conditions and impending water scarcity, it is certainly plausible to expect that the opportunity cost of water consumption could reach such levels. WDM is an effective method of reducing GHG emissions for programs that target hot water savings, and the cost of these programs was consistent with non–water-related programs that target GHG emission reductions.

  PublisherOA PDFDOI

• A metagenomic study of antibiotic resistance genes in a hypereutrophic subtropical lake contaminated by anthropogenic sources

  The Science of The Total Environment · 2024-04-05 · 16 citations

  articleOpen access

  Antibiotic resistance genes (ARGs) are a major threat to human and environmental health. This study investigated the occurrence and distribution of ARGs in Lake Cajititlán, a hypereutrophic subtropical lake in Mexico contaminated by anthropogenic sources (urban wastewater and runoff from crop and livestock production). ARGs (a total of 475 genes) were detected in 22 bacterial genera, with Pseudomonas (144 genes), Stenotrophomonas (88 genes), Mycobacterium (54 genes), and Rhodococcus (27 genes) displaying the highest frequencies of ARGs. Among these, Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed the highest number of ARGs. The results revealed a diverse array of ARGs, including resistance to macrolides (11.55 %), aminoglycosides (8.22 %), glycopeptides (6.22 %), tetracyclines (4 %), sulfonamides (4 %), carbapenems (1.11 %), phenicols (0.88 %), fluoroquinolones (0.44 %), and lincosamides (0.22 %). The most frequently observed ARGs were associated with multidrug resistance (63.33 %), with MexF (42 genes), MexW (36 genes), smeD (31 genes), mtrA (25 genes), and KHM-1 (22 genes) being the most common. Lake Cajititlán is a recreational area for swimming, fishing, and boating, while also supporting irrigation for agriculture and potentially acting as a drinking water source for some communities. This raises concerns about the potential for exposure to antibiotic-resistant bacteria through these activities. The presence of ARGs in Lake Cajititlán poses a significant threat to both human and environmental health. Developing strategies to mitigate the risks of antibiotic resistance, including improving wastewater treatment, and promoting strategic antibiotic use and disposal, is crucial. This study represents a significant advancement in the understanding of antibiotic resistance dynamics in a hypereutrophic subtropical lake in a developing country, providing valuable insights for the scientific community and policymakers.

  PublisherDOI

• Compounding one problem with another? A look at biodegradable microplastics

  The Science of The Total Environment · 2024-06-10 · 36 citations

  articleOpen access

  Environmental concerns about microplastics (MPs) have motivated research of their sources, occurrence, and fate in aquatic and soil ecosystems. To mitigate the environmental impact of MPs, biodegradable plastics are designed to naturally decompose, thus reducing the amount of environmental plastic contamination. However, the environmental fate of biodegradable plastics and the products of their incomplete biodegradation, especially micro-biodegradable plastics (MBPs), remains largely unexplored. This comprehensive review aims to assess the risks of unintended consequences associated with the introduction of biodegradable plastics into the environment, namely, whether the incomplete mineralization of biodegradable plastics could enhance the risk of MBPs formation and thus, exacerbate the problem of their environmental dispersion, representing a potentially additional environmental hazard due to their presumed ecotoxicity. Initial evidence points towards the potential for incomplete mineralization of biodegradable plastics under both controlled and uncontrolled conditions. Rapid degradation of PLA in thermophilic industrial composting contrasts with the degradation below 50 % of other biodegradables, suggesting MBPs released into the environment through compost. Moreover, degradation rates of <60 % in anaerobic digestion for polymers other than PLA and PHAs suggest a heightened risk of MBPs in digestate, risking their spread into soil and water. This could increase MBPs and adsorbed pollutants' mobilization. The exact behavior and impacts of additive leachates from faster-degrading plastics remain largely unknown. Thus, assessing the environmental fate and impacts of MBPs-laden by-products like compost or digestate is crucial. Moreover, the ecotoxicological consequences of shifting from conventional plastics to biodegradable ones are highly uncertain, as there is insufficient evidence to claim that MBPs have a milder effect on ecosystem health. Indeed, literature shows that the impact may be worse depending on the exposed species, polymer type, and the ecosystem complexity.

  PublisherDOI

Recent grants

• Advancement of a Sustainable Microbial Wastewater Treatment Process for the Removal of Phosphorus

  NSF · $320k · 2006–2010

• CAREER: Association of Pathogens with Wastewater Particles-Impact on the Biological Quality of Post-Disinfected Wastewater Effluents

  NSF · $150k · 2004–2006

• A Novel EBM Process Utilizing Renewable Biopolymers to Manufacture Natural Fiber Reinforced Thermoplastic Composites

  NSF · $200k · 2004–2008

Frequent coauthors

• Mary R. Arkoosh

  NOAA National Marine Fisheries Service Northwest Fisheries Science Center

  30 shared

• Jeannie L. Darby

  University of California, Davis

  29 shared

• Edward Spang

  University of California, Davis

  28 shared

• Lyndal L. Johnson

  NOAA National Marine Fisheries Service

  23 shared

• Katrina Jessoe

  University of California, Davis

  21 shared

• Timothy R. Ginn

  20 shared

• Gabriel Lade

  Macalester College

  18 shared

• Tracy K. Collier

  Western Washington University

  18 shared

Awards & honors

• 2015 & 2017 US Department of Energy Solar Decathlon Award
• 2013 Ray B. Krone Endowed Professorship
• 2001 NSF Career Award
• 2007 People Prosperity and Planet (P3) Award: National Stude…
• 2007 People Prosperity and Planet (P3) Award: National Stude…