Wastewater Collection Systems Research Articles

Water strategies and practices for sustainable development in the semiconductor industry

Semiconductor manufacturing is a rapidly growing industry and water-intensive industry. Water strategy formulation and decisions can be crucial factors in realizing the sustainable development of the semiconductor industry. This study surveyed the sustainability reports of 24 semiconductor corporations and investigated their water strategies and practices. Water targets proposed in the early stage of the 21st century are summarized. Water recycling, reuse, and restoration were the main strategies. Reverse osmosis played a dominant role in water treatment and reclamation. Classified wastewater collection and separate treatment systems have contributed greatly to improvement of water recycling rate in industrial parks. Finally, a future water cycle system for semiconductor manufacturing parks is proposed, which comprises water source, water use and recycling, and water discharge. This study is of theoretical and practical significance for the formulation and implementation of water strategies in the semiconductor industry to help accomplish its sustainable development with rapid growth.

Leveraging an established neighbourhood-level, open access wastewater monitoring network to address public health priorities: a population-based study

Before the COVID-19 pandemic, the US opioid epidemic triggered a collaborative municipal and academic effort in Tempe, Arizona, which resulted in the world's first open access dashboard featuring neighbourhood-level trends informed by wastewater-based epidemiology (WBE). This study aimed to showcase how wastewater monitoring, once established and accepted by a community, could readily be adapted to respond to newly emerging public health priorities. In this population-based study in Greater Tempe, Arizona, an existing opioid monitoring WBE network was modified to track SARS-CoV-2 transmission through the analysis of 11 contiguous wastewater catchments. Flow-weighted and time-weighted 24 h composite samples of untreated wastewater were collected at each sampling location within the wastewater collection system for 3 days each week (Tuesday, Thursday, and Saturday) from April 1, 2020, to March 31, 2021 (Area 7 and Tempe St Luke's Hospital were added in July, 2020). Reverse transcription quantitative PCR targeting the E gene of SARS-CoV-2 isolated from the wastewater samples was used to determine the number of genome copies in each catchment. Newly detected clinical cases of COVID-19 by zip code within the City of Tempe, Arizona were reported daily by the Arizona Department of Health Services from May 23, 2020. Maricopa County-level new positive cases, COVID-19-related hospitalisations, deaths, and long-term care facility deaths per day are publicly available and were collected from the Maricopa County Epidemic Curve Dashboard. Viral loads of SARS-CoV-2 (genome copies per day) measured in wastewater from each catchment were aggregated at the zip code level and city level and compared with the clinically reported data using root mean square error to investigate early warning capability of WBE. Between April 1, 2020, and March 31, 2021, 1556 wastewater samples were analysed. Most locations showed two waves in viral levels peaking in June, 2020, and December, 2020-January, 2021. An additional wave of viral load was seen in catchments close to Arizona State University (Areas 6 and 7) at the beginning of the fall (autumn) semester in late August, 2020. Additionally, an early infection hotspot was detected in the Town of Guadalupe, Arizona, starting the week of May 4, 2020, that was successfully mitigated through targeted interventions. A shift in early warning potential of WBE was seen, from a leading (mean of 8·5 days [SD 2·1], June, 2020) to a lagging (-2·0 days [1·4], January, 2021) indicator compared with newly reported clinical cases. Lessons learned from leveraging an existing neighbourhood-level WBE reporting dashboard include: (1) community buy-in is key, (2) public data sharing is effective, and (3) sub-ZIP-code (postal code) data can help to pinpoint populations at risk, track intervention success in real time, and reveal the effect of local clinical testing capacity on WBE's early warning capability. This successful demonstration of transitioning WBE efforts from opioids to COVID-19 encourages an expansion of WBE to tackle newly emerging and re-emerging threats (eg, mpox and polio). National Institutes of Health's RADx-rad initiative, National Science Foundation, Virginia G Piper Charitable Trust, J M Kaplan Fund, and The Flinn Foundation.

Assessment of limited downstream nitrate dosing for sulphide control in pressure sewers: case study in Germany

Abstract Odour release from sewer systems is an established environmental issue affecting many cities worldwide. A key indicator for the severity of the odour problem in sewer systems is linked to the amount of sulphide produced and released as hydrogen sulphide (H2S) into the urban environment. For this reason, an in-depth understanding of the biochemical processes of sulphurous compounds in sewer systems is an underlying base point for designing and implementing odour control strategies for sewer systems. This contribution focuses on a field study on the monitoring and assessing chemical dosing on a 9.0 km pressure sewer in Ueckermünde, Germany. Online H2S measurements indicated a daily reoccurrence of sulphide spikes between 4:00 and 8:00 am during the monitoring period. During this period, the wastewater slugs exiting the sewer section remained in the dosed section of the pipe the longest, and regeneration of sulphide production began after 3 hours, causing the hydrogen sulphide spikes. The proposed dosing strategy provides a cost-effective and efficient solution for sulphide build-up in long pressure sewers that connect rural areas to centralised wastewater collection and treatment systems.

Precipitation, tidal and river level impacts on influent volumes of combined wastewater collection systems: A regional analysis

Wastewater treatment plants (WWTPs) that treat both foul and storm wastewater will experience significant pressure due to changing precipitation patterns and other geophysical parameters. Limited work has been done to understand the links between factors such as tidal and river levels, precipitation, and influent volumes to WWTPs. This paper analyses the variations of precipitation and their link with influent volumes. The study adopts a new approach to understand influent volume variations by taking into consideration, the combined and individual impacts of tidal and river levels in addition to precipitation; a topic that has not been examined in literature to date. It was found that, on a daily basis, precipitation, tidal elevation, and river levels were each statistically significant in explaining variations in daily influent volumes. On a monthly scale, the combined effects of average daily precipitation and the number of zero rainfall days contributed to the changes in influent volumes. Lastly, this paper proposed monthly pooled spatio-temporal analysis to understand the variable nature of monthly averaged daily influent volumes. These findings will help stakeholders in wastewater management with long-term planning and investment including responses to changing precipitation patterns and their impact on wastewater infrastructure.

Sanitary Sewerage Master Plan for the Sustainable Use of Wastewater on a University Campus

Wastewater collection, transport, and treatment systems are essential to ensure human and environmental well-being. The Escuela Superior Politécnica del Litoral (ESPOL), has been implementing various sanitary sewerage systems; however, population growth has given rise to discussion on the installed capacity versus the necessary capacity for the future population in the sustainable management of water resources. Therefore, this study aimed to develop a sanitary sewerage master plan by analysing the existing situation and applying technical criteria for the sustainable use of wastewater on a university campus. The methodology consisted of (i) evaluation and diagnosis of the area studied through data collection and processing, (ii) design of the sanitary sewerage system considering area-expansion zones, and (iii) SWOT analysis of a proposal to enhance wastewater transport and treatment systems. The proposal contemplates designing a sanitary sewer system that will manage the collection, transport, and treatment of wastewater over 15 years for 5667 inhabitants located in three expansion zones with occupation periods of 5, 10, and 15 years. The sewerage system comprises a pipe network 1.19 km long and 200 mm in diameter, transporting 12.37 L/s of wastewater generated to two treatment systems that guarantee efficient depuration and subsequent reuse. This design was complemented by a SWOT analysis of the existing sanitation system developed by experts in the area, which included optimising existing treatment systems and reusing wastewater for irrigation of green areas as tertiary treatment within the circular economy. The methodology used in the study allows us to offer a tool for efficiently managing wastewater on a university campus, guaranteeing human well-being, and promoting the circular economy of water.

Neighborhood-Scale Urban Water Reclamation with Integrated Resource Recovery for Establishing Nexus City in Munich, Germany: Pipe Dream or Reality?

With the rapid expansion of cities due to population growth and urbanization, conventional centralized wastewater collection and treatment systems are slowly becoming a burden; expensive maintenance is required for aging plants and piping infrastructure, the cost of expanding the capacity to cover demand from population growth, and new regulations for tighter control over certain pollutants such as micropollutants. As an alternative to this system, this study discusses the feasibility of decentralized treatment systems at the neighborhood scale. Taking a Water-Energy-Food (WEF) Nexus approach, such systems can support water and energy conservation, recovery of water, energy, and nutrients as well as generation of energy from wastewater, be customized to individual water and energy requirements, and eliminate the need for lengthy pipe networks. The method employed in this study is comparing the economic feasibility of the status quo to a proposed decentralized solution. The study finds that the costs of implementing a hypothetical decentralized water reclamation with an integrated resource recovery system using an anaerobic membrane bioreactor (AnMBR) in a downtown high-density neighborhood of the city of Munich, Germany, can theoretically be recuperated within two years. This alternative system may cost 60% of what it costs to run the centralized system. By linking the AnMBR to a biogas digestor and using systematically harvested organic waste as a co-substrate, the decentralized system can generate enough energy to run itself and even feed some energy to the grid. This study is highly hypothetical, yet generating evidence such as this can support a systemic socio-technical transition towards a more circular economy with optimal resource recovery.

Method of cost-effectiveness-based total maximum allocated load index and measures of nitrogen and phosphorus pollutants on jurisdictions in Jiangsu coast, China

Cost-effective total maximum allocated load (TMAL) management of land-based pollutants is required to promote sustainable and healthy development of coastal areas. For the high concentrations of nitrogen and phosphorus pollutants and the deterioration in water quality in the coastal waters of Jiangsu Province, China, the TMALs of total nitrogen (TN) and total phosphorus (TP) pollutants within jurisdictions were calculated using a cost-efficiency optimization calculation method with a 3D hydrodynamic water quality model. This method is suitable for collaborative pollution prevention and land–sea integration management in coastal areas. Our calculation results showed that the emission TMALs of TN and TP in 43 jurisdictions near the coast of Jiangsu Province were approximately 8.6 × 104 and 0.8 × 104 ton/a, respectively, and the source TMALs were 55.8 × 104 and 14.9 × 104 ton/a, respectively. The high concentrations of nitrogen and phosphorus in these waters were caused mainly by Yancheng, Suqian and Lianyungang City. The average responsibility sharing rates (the responsibility sharing of land-based over-pressured administrative areas to marine pollution areas) of these three cities were 48.3%, 23.4%, and 12.2%, respectively. Regarding over-pressured administrative areas (the administrative regions where the discharge exceeds the allocation capacity), we suggest pollution prevention and technical control measures based on the cost-effectiveness optimization method. First, source control should be strengthened, including the control of industrial point source and agricultural nonpoint source pollution, which account for approximately 77.3% of total reduction. Second, it is necessary to strengthen the construction of the municipal wastewater collection and treatment system, which accounts for approximately 16.3% of total reduction. Further, it is necessary to perform wetland ecological restoration and implement capacity-increasing measures, which account for approximately 6.4% of total reduction. The cost-effectiveness optimization calculation method for the technical indicators of collaborative prevention and control of coastal pollution provides a scientific quantitative basis suitable for global coastal pollution control.

Effects of saltwater intrusion and sea level rise on aging and corrosion rates of iron pipes in water distribution and wastewater collection systems in coastal areas

Failure of water distribution and wastewater collection pipes can impact human health and environment due to potential contamination of water and soil in the surrounding areas, as well as service interruptions and road closures. This paper provides a quantitative assessment of projected shifts in failure rates of iron pipes due to saltwater intrusion and sea level rise in coastal areas. Probability of pipe failure depends on pipe characteristics, environmental parameters, and systems conditions. Analyses showed that saltwater intrusion and sea level rise can significantly affect the integrity of water and wastewater collection pipes due to potential changes in soil and groundwater characteristics that increase corrosion rates. Corrosion rate is intensified by increased conductivity of groundwater due to salinity. Coastal areas with subtropical climate have higher corrosion rates. The estimated lifetimes of ductile iron pipes are between 80 and 100 years. However, the actual service lifetimes can be significantly shorter. Pipes in subtropical areas corrode significantly faster than those in temperate climates. Presence of dissolved oxygen and chloride ion can significantly intensify the corrosion rates, shortening service times of iron pipes. Projections for pipe corrosion can help development of effective asset management strategies and for infrastructure maintenance planning in coastal areas that are vulnerable to sea level rise.

Sources, fates and treatment strategies of typical viruses in urban sewage collection/treatment systems: A review

The ongoing coronavirus pandemic (COVID-19) throughout the world has severely threatened the global economy and public health. Due to receiving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a wide variety of sources (e.g., households, hospitals, slaughterhouses), urban sewage treatment systems are regarded as an important path for the transmission of waterborne viruses. This review presents a quantitative profile of the concentration distribution of typical viruses within wastewater collection systems and evaluates the influence of different characteristics of sewer systems on virus species and concentration. Then, the efficiencies and mechanisms of virus removal in the units of wastewater treatment plants (WWTPs) are summarized and compared, among which the inactivation efficiencies of typical viruses by typical disinfection approaches under varied operational conditions are elucidated. Subsequently, the occurrence and removal of viruses in treated effluent reuse and desalination, as well as that in sewage sludge treatment, are discussed. Potential dissemination of viruses is emphasized by occurrence via aerosolization from toilets, the collection system and WWTP aeration, which might have a vital role in the transmission and spread of viruses. Finally, the frequency and concentration of viruses in reclaimed water, the probability of infection are also reviewed for discussing the potential health risks.

Impact of a methane emission tax on circular economy scenarios in small wastewater treatment plants.

This paper analyzes the impact of methane emissions taxation on the recovery of the investments required for implementing technologies that use biogas energy in small wastewater treatment plants (WWTPs) in Brazil. It is based on the hypothesis that the adoption of a national methane emission tax policy would encourage small WWTPs to become sustainable power plants. The procedure involved 173 anaerobic plants to analyze: (a) methane production; (b) available useful energy; (c) investments and avoided costs for implementing STHIL system (thermal drying sludge) and motor generator (electricity generation); (d) financial impact for two scenarios (C1: no emissions tax; C2: with tax). Positive environmental and financial results were observed for WWTPs, varying according to the period of time analyzed for both technologies. Investments must be made in cogeneration in anaerobic WWTPs for achieving satisfactory results. Taxation must not be viewed simply as a punitive instrument; on the contrary, it should be seen as a tool to encourage continuous process improvement. The circular economy may support the enlargement of the wastewater collection and treatment system, guaranteeing widespread sanitation conditions in urban areas. However, the actual implementation of a methane emission tax in Brazil still requires many rounds of discussion among sanitation companies, government, and civil society, to establish emission limits, and unit taxes, as well as to consolidate a carbon trade to follow through with this decision in the sanitation sector.

Implementing wastewater monitoring on American Indian reservations to assess community health indicators

Healthcare access and health-related information for American Indian/Alaska Native (AIAN) communities is often limited. A potential solution to acquire additional population level health data is through wastewater-derived measurements, a method termed wastewater-based epidemiology (WBE), however, due to often remote locations with rudimentary wastewater infrastructure, the feasibility of implementing WBE on an AIAN reservation is unclear. In this study, we i) performed a preliminary assessment of percent connectivity of the top 10 most populous tribal reservations using available wastewater treatment facility information from the Environmental Protection Agency Enforcement and Compliance History Online database and satellite imagery, and ii) performed a sampling campaign on a select tribal reservation to measure common WBE indicators of health and behavior. Results indicate that, on average, approximately 81 ± 23% of tribal residents are connected to some form of aggregated wastewater collection system. On the sampled reservation, 6 communities comprising 7500 people were sampled across 160 km of reservation land using active samplers successfully deployed within the sewer network upstream of terminal lagoon systems. Results showed detectable levels of 7 opioids, 1 opioid maintenance medication, 5 stimulants, 1 hallucinogen, and chemical indicators of alcohol, nicotine, caffeine, and an over-the-counter cough suppressant. These results illustrated the feasibility in implementing WBE in rural and remote communities where information on community health may be lacking.

Efficient Metaheuristic Algorithms for a Robust and Sustainable Water Supply and Wastewater Collection System

An efficient design of a water supply and wastewater collection system is significantly important to tackle the natural uncertainty of this system and the sustainable development goals in developing countries like Iran. To address the natural uncertainty in the water supply and the challenge of global warming, this design must be robust and this motivates a robust optimization. To consider the sustainability criteria, this design should cover all economic, environmental and social impacts. Hence, this study develops innovative solutions based on recent and traditional metaheuristic algorithms for a robust and sustainable water supply and wastewater collection system. Red deer algorithm (RDA) and Keshtel algorithm (KA) as the recent algorithms, are employed. These recent algorithms are compared with the state-of-the-art methods like genetic algorithm (GA) and particle swarm optimization (PSO). An application of our model and algorithms, is tested on a case study in North Khorasan province. After performing some analyses on the performance of our algorithms and sensitivities on the model, a discussion is provided to conclude managerial insights and findings for practitioners in the applied system.

Exploration of wastewater management behavior for enhancing water conservation in urban area, Thailand

<abstract> <p>While millions of people around the world die from natural water infections per day because of insufficient wastewater collection systems to cover all communities, 80 percent of used water is still released to the river in Thailand nowadays. As a result, the wastewater management (WWM) behavior of people is critical to water conservation. WWM, on the other hand, was fraught with high expenses and inconvenient installation, and earlier research had paid little attention to it. Thus, this research aims to study the socio-economic, cognition, opinions, and perception of information factors for analysis further of the factors affecting the WWM of people in urban areas, Thailand. This study applied multiple regression analysis from questionnaires survey of nine communities in Krathum Baen municipality, Samut Sakhon Province which is a semi-industrial area, crowded settlement, and risen wastewater unexpectedly along the Tha Chin River. The findings reveal that people in study areas have a moderate level of cognition and opinion toward WWM behavior. Perception of information was the best variable to describe the people's WWM behaviors in urban areas. Addressing the empirical results could contribute to water conservation planning, people engagement, and appropriately promoting WWM behaviors related to urban people.</p> </abstract>

Enabling Automatic Detection of Anomalies in Wastewater: A Highly Simplified Approach to Defining “Normal” in Complex Chemical Mixtures

Wastewater treatment demands management of influent conditions to stabilize biological processes. Generally wastewater collection systems lack advance warning of approaching water parcels with anomalous characteristics, which could then be diverted for testing or pre-treatment. A major challenge in achieving this goal is identifying anomalies against the complex chemical background of wastewaters. This work evaluates unsupervised clustering methods to characterize “normal” wastewater characteristics, using >17 months of 10-min resolution absorbance spectrometry data collected at an operating wastewater treatment facility. Comparison of results using K-means, GMM, Hierarchical, and DBSCAN clustering shows minimal intra-cluster variability achieved using K-means. The four K-means clusters include three representing 99% of samples, with the remaining cluster (<0.3% of samples) representing atypical measurements, demonstrating utility in identifying both underlying modalities of wastewater characteristics and outliers. K-means clustering provides a better separation than grouping based on factors such as month, precipitation, or flow (with 25% overlap at 1-σ level, compared to 93, 93, and 83%, respectively) and enables identification of patterns that are not visible in factor-driven grouping, e.g., shows that summer and November months have a characteristic type of behavior. When evaluated with respect to wastewater influent changes occurring during the SARS-CoV-2 pandemic, the K-means approach shows a distinct change in strength of diurnal patterns when compared to non-pandemic periods during the same season. This method may therefore be useful both as a tool for fast anomaly detection in wastewaters, contributing to improved infrastructure resilience, as well for providing overall analysis of temporal patterns in wastewater characteristics.

An investigation into the role of treatment performance and soil characteristics of soil-based wastewater treatment systems.

Soil-based onsite wastewater treatment systems (OWTS) are becoming more important for the treatment and disposal of wastewater in areas that do not have central wastewater collection and treatment systems. However, there are concerns that OWTS may have adverse effects on public health and environment. The purpose of this study is to treat wastewater using a natural soil column in order to evaluate treatment system performance. Wastewater was applied to two different natural soils at different flow rates of 9, 18 and 36 L/day. The treatment performances of wastewater and geotechnical properties of the natural soils were examined. As a result of this study, the percentage of COD and SS removal in wastewater after soil column filtration ranged from 36.2% to 80.5% and 84.4% to 97.9% respectively. pH values of wastewater after the filtration were measured at between 7.75 and 8.12. TP and TN removal rates were found in the range of 23.9-76.8% and 12.4-83.0%, respectively. The column effluent water was classified as both 'high hardness class' in terms of hardness and 'polluted water' in terms of conductivity. Column effluent water was found in 'low, medium, and high hazard' classes in terms of SAR. Whereas the PL values of the natural soils were found to increase by up to 4.8% in the filtration area, specific gravity decreased by nearly 1.1%. The values of LL, PI, maximum dry density, optimum water content, and permeability changed depending on the soil type. The UCS of the natural soils after wastewater filtration decreased by about 5.9%. It was concluded that natural soils have positive effects on treatment of wastewater in a short time.

Comprehensive investigation of SARS-CoV-2 fate in wastewater and finding the virus transfer and destruction route through conventional activated sludge and sequencing batch reactor

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA transmission route was thoroughly investigated in the hospital wastewater, sewage collection network, and wastewater treatment plants. Samples were taken on four occasions from December 2020 to April 2021. The performance of two different wastewater treatment processes of sequencing batch reactor (SBR) and conventional activated sludge (CAS) was studied for virus destruction. For this purpose, liquid phase, solid phase and bioaerosol samples were taken from different units of the investigated wastewater treatment plants (WWTPs). The results revealed that all untreated hospital wastewater samples were positive for SARS-CoV-2 RNA. The virus detection frequency increased when the number of hospitalized cases increased. Detection of viral RNA in the wastewater collection system exhibited higher load of virus in the generated wastewater in areas with poor socioeconomic conditions. Virus detection in the emitted bioaerosols in WWTPs showed that bioaerosols released from CAS with surface aeration contains SARS-CoV-2 RNA posing a potential threat to the working staff of the WWTPs. However, no viral RNA was detected in the bioaerosols of the SBR with diffused aeration system. Investigation of SARS-CoV-2 RNA in WWTPs showed high affinity of the virus to be accumulated in biosolids rather than transporting via liquid phase. Following the fate of virus in sludge revealed that it is completely destructed in anaerobic sludge treatment process. Therefore, based on the results of the present study, it can be concluded that receiving water resources could not be contaminated with virus, if the wastewater treatment processes work properly.

Identification of sampling points for the detection of SARS-CoV-2 in the sewage system.

A suitable tool for monitoring the spread of SARS-CoV-2 is to identify potential sampling points in the wastewater collection system that can be used to monitor the distribution of COVID-19 disease affected clusters within a city. The applicability of the developed methodology is presented through the description of the 72,837 population equivalent wastewater collection system of the city of Nagykanizsa, Hungary and the results of the analytical and epidemiological measurements of the wastewater samples. The wastewater sampling was conducted during the 3rd wave of the COVID-19 epidemic. It was found that the overlap between the road system and the wastewater network is high, it is 82 %. It was showed that the proposed methodological approach, using the tools of network science, determines confidently the zones of the wastewater collection system and provides the ideal monitoring points in order to provide the best sampling resolution in urban areas. The strength of the presented approach is that it estimates the network based on publicly available information. It was concluded that the number of zones or sampling points can be chosen based on relevant epidemiological intervention and mitigation strategies. The algorithm allows for continuous effective monitoring of the population infected by SARS-CoV-2 in small-sized cities.

Assessment and modeling of sewer network development utilizing Arc GIS and SewerGEMS in Kabul city of Afghanistan

The absence of a wastewater collection, management, and disposal scheme is one of Kabul’s most serious environmental issues. This has resulted in both health and ecological problems. This research used Arc GIS and SewerGEMS tools to assess the viability of a decentralized sewerage collection model in the research area. The research area was chosen as the city’s 5th district. Land-use and land-cover, Digital Elevation Model (DEM), and Satellite data were used to construct the network’s geometry in the Arc map environment. SewerGEMS software was used to perform hydraulic simulation and modeling. The variables were regulated based on the results of the study using conventional wastewater topology guidelines. Based on the outputs of hydraulic analysis, it is concluded that the decentralized wastewater collection system would be the best option for the area. It can be deduced from hydraulic design findings that the hydraulic model was successfully developed and built. The methodology can be applied for the development of future wastewater master plans of the city.

Forecasting saltwater intrusion volume and sulfate content in a wastewater collection system. Case study: Barreiro/Moita WWTP, Portugal

Abstract The presence of salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewater Treatment Plant (WWTP), Portugal. The intrusion occurs throughout damaged sections and direct vectors in the wastewater collection system, during high tide levels, changing the wastewater characteristics and impacting the WWTP process. This study designed models to quantify this problem, enabling more effective countermeasures within the right timing. The proposed models estimate the average volume of salt water and sulfate () load for each high tide period. The laboratory results show strong correlations between the influent electrical conductivity (EC) and percentage of salt water in WWTP inflow (0.9909), and between EC and concentration in WWTP influent (0.9797). The forecast models also show good correlation between the high tide levels with volume of salt water (0.9145) and load (0.9162) entering the system. Considering the total monthly inflow, the highest percentage of salt water registered in WWTP inflow was 3.6%. During high tide periods, critical situations have been assessed with up to 53.9% of salt water in the WWTP inflow, increasing energy consumption and costs in pumping stations.

AWWA Water Science Author Spotlight

Having recently published an article in AWWA Water Science, Anthony Kennedy answered questions from the publication's editor-in-chief, Kenneth L. Mercer, about the research. Stannous Chloride Reduction–Filtration for Hexavalent and Total Chromium Removal From Groundwater Anthony Kennedy, Rachel Croft, Leah Flint, and Miguel Arias-Paic At the time of the research, I worked at the United States Bureau of Reclamation (USBR). I currently work at Corona Environmental Consulting, developing a research focus related to advanced water treatment processes and process optimization. Anthony enjoys backcountry skiing in Grand Teton National Park, March 2021. I've had two great mentors so far in my career: Professor Summers at CU Boulder and Dr. Miguel Arias-Paic at USBR. Professor Summers’ best advice was to focus on what is important and to not get caught up in minutia that can degrade your confidence. Dr. Arias-Paic said that for most problems we face in water treatment, a technological solution already exists; we just need to be more creative in how we apply those technologies. The primary motivations for the research were the cost and logistical challenges associated with brine generated from ion exchange treatment. Although ion exchange brine volume from regenerations can be significantly minimized, it still contains high levels of total dissolved solids and hexavalent chromium, in addition to other metals such as arsenic, vanadium, and uranium, and must ultimately face hazardous waste disposal. With stannous chloride, rapid-sand-filter backwash waste can also contain high levels of the less toxic trivalent chromium, but without the high total dissolved solids, making it more suitable for discharge to wastewater collection systems or sludge-drying ponds. In my personal life, I'm very conscious of my consumption and environmental impact. In my research, I try to simplify technologies and processes such that they use a more sustainable material or consume fewer materials, chemicals, etc., compared with conventional technologies, with the goal of meeting the same treatment target. Three challenges are (1) actual implementation of water treatment research; (2) widespread adoption and implementation of direct potable reuse to mitigate the effects of climate change on the drinking water industry; and (3) funding for drinking water, wastewater, and water reuse infrastructure. In July 2021, Anthony visited Parco Naturale Puez Odle in South Tyrol, Italy. I grew up near Pittsburgh, which has seen a comeback due in large part to a hardworking, motivated, but also modest and humble, populace. I take the same approach with my research—just sound, thorough research that can be used to improve the design, operation, and potentially the sustainability of water treatment facilities. To learn more about Anthony's research, visit the article, available online at https://doi.org/10.1002/aws2.1174.