Wastewater Treatment Services Research Articles

Ultraviolet disinfection impacts the microbial community composition and function of treated wastewater effluent and the receiving urban river.

BackgroundIn the United States, an estimated 14,748 wastewater treatment plants (WWTPs) provide wastewater collection, treatment, and disposal service to more than 230 million people. The quality of treated wastewater is often assessed by the presence or absence of fecal indicator bacteria. UV disinfection of wastewater is a common final treatment step used by many wastewater treatment plants in order to reduce fecal coliform bacteria and other pathogens; however, its potential impacts on the total effluent bacterial community are seemingly varied. This is especially important given that urban WWTPs typically return treated effluent to coastal and riverine environments and thus are a major source of microorganisms, genes, and chemical compounds to these systems. Following rainfall, stormflow conditions can result in substantial increases to effluent flow into combined systems.MethodsHere, we conducted a lab-scale UV disinfection on WWTP effluent using UV dosage of 100 mJ/cm2 and monitored the active microbiome in UV-treated effluent and untreated effluent over the course of 48 h post-exposure using 16S rRNA sequencing. In addition, we simulated stormflow conditions with effluent UV-treated and untreated effluent additions to river water and compared the microbial communities to those in baseflow river water. We also tracked the functional profiles of genes involved in tetracycline resistance (tetW) and nitrification (amoA) in these microcosms using RT-qPCR.ResultsWe showed that while some organisms, such as members of the Bacteroidetes, are inhibited by UV disinfection and overall diversity of the microbial community decreases following treatment, many organisms not only survive, but remain active. These include common WWTP-derived organisms such as Comamonadaceae and Pseudomonas. When combined with river water to mimic stormflow conditions, these organisms can persist in the environment and potentially enhance microbial functions such as nitrification and antibiotic resistance.

Sustainability Assessment of Asset Management Decisions for Wastewater Infrastructure Systems—Implementation of a System Dynamics Model

The goal of this case study is to demonstrate the application and utility of a developed System Dynamics (SD) model to assess the sustainability of strategic decisions for managing the wastewater collection (WWC) pipe network system for a medium-size municipality in Southern Ontario. Two asset management scenarios, suggested by the research-partnered municipality, are adapted based on the acceptable maximum fraction of pipes in the worst condition (ICG5) being equal to (1) 10% of the network-length/year, and (2) the initial 2.8% of network-length/year for the entire life cycle of the asset. The urban densification scenarios are restricted to a 50% urban densification rate. The least maximum rehabilitation rates of 1.41% and 1.85% of network length/year are found necessary to keep the ICG5 pipes fractions below the selected 10% and 2.8% thresholds, respectively. The maximum and minimum user fee-hike rates for WWC and wastewater treatment (WWT) services are adjusted to support the financial self-sustainability aspect. Results from the SD model, as presented over a 100 year simulation period, show that an accelerated rehabilitation strategy will have a lower financial cost with the lowest greenhouse gas (GHG) emissions. This study highlights the implications of integrating asset management of wastewater-collection and -treatment systems. Applying such an integrated SD model will help decision makers to forecast the future trends related to social, economic, and environmental performances of wastewater infrastructure systems, and evaluate the behavior of interrelated and complex WWC and WWT systems to find synergistic cost-saving opportunities while at the same time improve sustainability.

Wind Point Partners to sell Valicor Environmental Services

Private equity firm Wind Point Partners has entered into a definitive agreement to sell Valicor Environmental Services, a provider of non-hazardous wastewater treatment services in North America, to Pritzker Private Capital.

Cost of Urban Wastewater Treatment and Ecotaxes: Evidence from Municipalities in Southern Europe

The principle of cost recovery established by the Water Framework Directive underlines the need for tax rates, which can raise enough revenue to finance the cost of treatments applied to wastewater. The objective of this research is to gain an understanding the different types of charges related to urban wastewater treatment that can be levied by the authorities responsible for this service. This paper also aims to determine whether these taxes contribute to guaranteeing the economic feasibility of the wastewater treatment plants. The proposed methodological approach is applied to 18 municipalities of a province in southern Europe in 2017. The results confirm that in most of these cases, the taxes levied do not guarantee adequate tax revenues to cover the running, maintenance and investment costs of municipal wastewater treatment plants. This situation leads to a lack of financial self-sufficiency in the wastewater management service, meaning that the imbalance between income and expenditure has to be covered by government subsidies. The results of this study will help guide authorities around the world that are in charge of managing urban wastewater treatment services.

IPTEKS STANDAR PELAYANAN MINIMAL PADA DINAS PEKERJAAN UMUM DAN PENATAAN RUANG DAERAHPROVINSI SULAWESI UTARA.

Reform in administration of government in Indonesia have cause the occurance of a number important and fundamental changes in governance which ultimately has implication for the implementation of public services in the region. In accordance with the provisions of article 11 and article 14 ofLaw of Year 2004 Number 32 concerning Regional Government, Government Regulation Number 65 of 2005 concerning Guidelines for Preparation and Application of Minumum Standards Service (SPM). The Government Regulation is a reference for the Ministry / Institutions in the preparation of MSS and become reference points for the government regions in implementing SPM (MSS).Basic services in the Minimum Service Standards are compulsory government affairs that are carried out by regional Governments both Provincial and Regional Governments. Government Affairs is obligatory relating to basic services which subsequently becomes the type of SPM, one of which is SPM in the Field Public Works. Types of Basic Services for SPM in Public Works and Spatial Planning for Provincial and District / City Governments are as follows. Provincial government : meeting the needs of bulk drinking water across districts / cities and provision of cross-regency / municipal regional domestic wastewater treatment service Keywords : Minimum Service Standards, Implementation, Government

Wastewater Reflections in Consumer Mind: Evidence from Sewage Services Consumer Behaviour

Environmental concerns have become an important decision-making determinant for consumers. Hundreds of emerging pollutants and their metabolites are listed as present in European aquatic environments and human settlements are blamed as major sources of water pollution. It was assumed that as long as water treatment is not totally effective and it requires a high amount of energy and resources, household’s contribution through correct behaviour in relation to the load of waste they discharge in the sewage system can reduce efforts towards wastewater treatment. Consequently, the main objective of this study was to investigate households’ perception and behaviour related to wastewater treatment services. Results are based on a random survey with a sample of 125 Romanian consumers of water supply and sewage services. A key finding is that investigated wastewater services consumers perceive the effect of discharging untreated wastewater in the environment as highly negative both on human health and on the environment, thus pointing out the importance associated by them to water treatment. This research argues that understanding wastewater services consumer behaviour enlarges the way toward reducing environmental disturbances.

ESTIMATION OF WILLINGNESS TO PAY FOR WASTEWATER TREATMENT SERVICE IMPROVEMENT IN MALAYSIA

As populations increase by leaps and bounds, it places more pressure on the environment and threatening sources of fresh water supplies, it was recognized that the problem of wastewater needed proper management in Malaysia. This study is undertaken to assist the relevant governmental bodies and service providers to identify an improved wastewater management strategy from the consumer perspectives. This paper applies a structural equation model (SEM) to analyze willingness to pay for wastewater treatment services improvement, based on a cross-sectional dataset of 600 randomly selected urban households in Shah Alam, Bangi, Kajang and Banting areas. The study applies focus group discussions, variables such as environmental awareness (green product), household attitude (water consumption), perceptions (sewerage and wastewater treatment services) and service improvements (willingness to pay) were identified. The main results indicate that environmental awareness, household attitude and perceptions on sewerage services have a positive influence on the service improvements. Households attitude on sewerage and wastewater treatment services are the main determinants of willingness to pay and strongly interact (87 percent) with sewerage service improvement. In conclusion, the methodology applied to measure the household attitudes provides valuable information to policy makers regarding main factors that improve wastewater treatment service efficiency.Keywords: Wastewater; Structural Equation Model; Willingness-To-Pay.

Energy Efficiency Drivers in Wastewater Treatment Plants: A Double Bootstrap DEA Analysis

The relevance of wastewater treatment service has increased in recent years, since it has a significant impact on the natural environment. A treatment plant facilitates energy generation, the recovery of products from waste, and the reuse of wastewater for industrial and irrigation purposes. An indirect environmental effect is the high energy consumption for pumping water and for tank aeration. The objective of this research is to develop a tool for measuring the energy costs of wastewater treatment plants and identifying how they can be reduced. The method adopted is double-bootstrap data envelopment analysis. The results show that the variables with a significant influence on efficiency are the chemical oxygen demand concentration; plant capacity; rate of used capacity, which positively affects efficiency; weight of industrial customers, which exerts a negative impact; and aeration system, with a negative impact for turbines. This paper suggests the adoption of an effective control tool to monitor the costs drivers and energy expenditure of water utilities.

Identifying the performance drivers of wastewater treatment plants through conditional order-m efficiency analysis

In European countries, wastewater treatment service is often provided by utilities, which have to comply with environmental laws and, at the same time, should control costs in order to restrain tariff growth and earn profits. By applying a conditional order-m efficiency method, this study provides some insights to the operational variables affecting the efficiency of 137 plants owned by a water utility operating in Tuscany, Italy. These performance drivers are categorized as: 1) wastewater features, 2) plant technology, 3) other plant features, 4) output quality, and 5) sludge disposal method. Starting from some controversial results from prior literature, this paper provides some useful insights on the best policies that could be adopted by a utility to catch cost savings.

Indicators of efficient urban water management

Over the past decade, water and wastewater utilities have been gradually replacing local municipalities in Israel as the providers of drinking water and wastewater treatment services. Most utilities serve one or two cities or several small municipalities, often operating at a low profit or even at a loss. This research examines the factors influencing the utilities' profitability, including the potential existence of economies of scale. The results show that for small utilities, an increase of 10,000 in population size is associated with an increase 0.5%-1% in gross margins, but this increase tapers off as the utilities grow larger. The profitability depends on many other factors, including the utility's age (experience) and physical location, as well as the municipality's structure and socio-economic rating; therefore, the optimal utility size varies greatly for each area.

Technology Options in a Dairy Plant: Assessing Whole-System Eco-Efficiency

<p class="emsd"><span lang="EN-GB">Industries are increasingly looking beyond their own fences to optimise their supply and delivery chains. Increasing industrial production costs for resources and costs to comply with stringent legislation have led many industries to look for more cost effective solutions. Establishing collaboration with water and energy utilities and other industries in the neighbourhood of the industrial production site is one option being analysed.</span></p><p class="emsd"><span lang="EN-GB">This paper presents how eco-efficiency analysis - at a system level going beyond the fences of an industrial production site - can calculate economic value and environmental impacts in such wider systems. The paper presents how the analysis can lead to the identification of eco-efficient solutions at a system level as well as at the level of each actor in the system.</span></p><p class="emsd"><span lang="EN-GB">The eco-efficiency analyses are based on the ISO standard ISO 14045. The water use system analysis comprises a dairy plant producing milk powder located in a production site in Holstebro, Denmark. The dairy uses water in its utility operation and in the dairy processes for purposes like cleaning (Cleaning in Place, CIP), rinse processes and standardization of products. </span></p><p class="emsd"><span lang="EN-GB">In the eco-efficiency analysis a water value chain is modelled in five stages: water supply, dairy production, wastewater treatment, energy production (biogas) and transport. The eco-efficiency analysis thus has another focus than a Water Footprint analysis, which also includes water use for feed production, water used at farm level and in some cases also includes the water use at retail and consumer level. The eco-efficiency study focus not only on water efficiency but also on and how energy saving technology options linked to water use could upgrade the whole-system eco-efficiency. </span></p><p class="emsd"><span lang="EN-GB">The identification of the environmentally weak stages as being emissions of climate gasses resulting from energy use and water resource enables the selection of alternative actions, which could upgrade the whole value chain and improve the overall eco-efficiency. Four innovative technologies in the dairy production stage and one in the wastewater treatment stage are examined and three alternative technology scenarios combining these technologies are formulated. All scenarios focus on resource efficiency, while one also focuses on reducing the emissions to water.</span></p><p class="emsd"><span lang="EN-GB">The eco-efficiency assessments showed that advanced oxidation and UV light treatment of the water stream separated from the milk stream had the highest eco-efficiency corresponding to an increase of 130% compared to the baseline for the freshwater resource depletion indicator. Anaerobic pretreatment of the dairy wastewater in the dairy plant had the highest eco-efficiency showing an increase of 10% as compared to the baseline for the climate gas indicator. For all other technologies and combinations of technologies the increases were significantly smaller. </span></p><p class="emsd"><span lang="EN-GB">The eco-efficiency assessment results provided a basis for workshops with the actors in the value chain to discuss how to anticipate distributional effects. The analysis of the economic performance clearly showed that the dairy plant had the highest economic performance due to the high value of their product and that investments in new technologies increased the economic performance even more. This was mainly caused by savings on costs for water supply and wastewater treatment services, which left the water utility with a reduced economic performance.</span></p>

Development and application of the Hicks-Moorsteen productivity index for the total factor productivity assessment of wastewater treatment plants

The assessment of the productivity change in wastewater treatment plants is essential to improve performance and reduce operational costs. Several indices are available to compute unit productivity, however some assessments are more reliable than others. In the absence of price data, the Malmquist productivity index is the most commonly applied; but it does not maintain total factor productivity properties under variable returns to scale technology. Hence, Malmquist productivity index is not a suitable index to compute total factor productivity change in wastewater treatment plants. The present study served to overcome such limitations by calculating, for the first time, total factor productivity changes in a sample of 204 Spanish wastewater treatment plants using the Hicks-Moorsteen productivity index. It is a multiplicatively-complete index, which can be decomposed as several sub-indices representing technical and efficiency changes. Therefore, this study also investigated the drivers of total factor productivity change in wastewater treatment plants. Results showed a 5.4% total factor productivity decline per year from 2003 to 2008 in the plants analysed. The primary driver in the reduction was efficiency change. Alternatively, technical change improved during the five years of study. The results of this study provide support for policymakers and managers in decision-making processes and contribute to the improvement of technical and economic wastewater treatment plants performance. In addition, it is evidenced that wastewater treatment plants current dependence on external energy sources should be reduced to improve productivity and reduce costs to citizens who pay for wastewater treatment services.

Economic effects of sewage and wastewater treatment service sector: an inter-industry analysis

The economic effects of sewage and wastewater treatment service (SWTS) sector on other sectors have been rarely investigated in the literature. This paper attempts to apply an inter-industry analysis to looking into the economic effects of the SWTS sector. To this end, the most recently published 2012 input-output table is used here. In particular, the SWTS sector is specified as exogeneous to identify the economic effects of the SWTS sector on other sectors. Production-inducing effect, value-added creation effect, and employment-inducing effect are quantified based on demand-driven model. Supply shortage effect and price pervasive effect are also analyzed employing supply-driven model and Leontief price model, respectively. The results show that production-inducing effect and value-added creation effect of a unit of investment or production in SWTS sector are estimated to be 1.7076 and 0.7392, respectively. The employment-inducing effect of one billion of investment or production in the SWTS sector is computed to be 11.0498 persons. The shortage effect of the SWTS sector amounts to 0.8417 won. The overall price effect of the 10% increase in the price of SWTS sector is calculated to be 0.0115%. This quantitative information can be utilized in predicting the economic effects of the SWTS sector-related activities or policy-making.

Application of the DIY carbon footprint calculator to a wastewater treatment works

The provision of water and wastewater treatment services exerts a huge operational cost on public financial resources. A substantial portion of the operational budget is made up of carbon-intensive energy costs. Energy is consumed in this sector in pumping, aeration, motor drives, administration, transportation and in the manufacture of chemicals such as polyelectrolyte, chlorine and ozone. The high electrical power consumption exerts added pressure on the environment in terms of greenhouse gas emissions. In order to manage the energy budget and develop climate-friendly technological options, Royal HaskoningDHV (RHDHV) has developed a do-it-yourself (DIY) Excel-based carbon footprint calculator to estimate the carbon equivalent emissions for a waterworks, a wastewater treatment works or a pumping station. The DIY carbon calculator computes Scope 1, Scope 2 and Scope 3 emissions. The DIY calculator starts with establishing the baseline carbon footprint of a works and shows the relative carbon equivalent emissions for different treatment stages. The next step involves the development of strategies to reduce the carbon footprint. Inherent within a wastewater treatment works is its ability to potentially generate its own ‘green’ energy by using anaerobically produced methane gas as a green energy alternative. This investigation demonstrates how the baseline carbon footprint of a wastewater treatment works can be reduced by considering viable options such as biogas to power generation, process re-design and drives to improve energy efficiency. Results show that the carbon calculator was able to demonstrate the effectiveness of carbon-reducing strategies in this energy-intensive sector. This further implies that the carbon calculator can be used as an additional management and decision support tool to assist an organisation towards a low carbon footprint. Keywords : carbon footprint calculator, carbon equivalent emissions, greenhouse gas, green energy, Scope 1, 2 and 3 emissions, emission factor, sustainability, energy factory

Integrated management of water resources in urban water system: Water Sensitive Urban Development as a strategic approach

The urban environment has to be concerned with the integrated water resources management, which necessarily includes the concept of basin unity and governance. The traditional urban water cycle framework, which includes water supply, sewerage and wastewater treatment services, is being replaced by a holistic and systemic concept, where water is associated with urbanism and sustainability policies. This global point of view cannot be ignored as new regulations demand systemic and environmental approaches to the administrations, for instance, in the management of urban drainage and sewerage systems. The practical expression of this whole cluster interactions is beginning to take shape in several countries, with the definition of Low Impact Development and Water Sensitivity Urban Design concepts. Intends to integrate this new strategic approach under the name: “Water Sensitive Urban Development” (WSUD). With WSUD approach, the current urban water systems (originally conceived under the traditional concept of urban water cycle) can be transformed, conceptual and physically, for an integrated management of the urban water system in new models of sustainable urban development. A WSUD implementing new approach to the management of pollution associated with stormwater in the urban water system is also presented, including advances in environmental regulations and incorporation of several techniques in Spain.

Using a new incentive mechanism to improve wastewater sector performance: The case study of Italy

The system of “Service Objectives”, introduced by the Italian National Strategic Framework 2007–2013, is an innovative results-oriented programme concerning 4 thematic areas (education, care for the elderly and children, management of municipal solid wastes and integrated water service) in which the Ministry of Economic Development and eight Southern Italy districts are involved. The system was initially associated to an incentive mechanism which provided subsidies for a total amount of EUR 3 billion from the national Underdeveloped Areas Fund, according to the achievement of specific targets set for 11 service indicators in 2013. The indicators used for the integrated water service refer to the efficiency in water supply service as well as the coverage of wastewater treatment service. The aim of the study is to describe the activities carried out in Italy by the ENEA Agency in order to define a new performance indicator for wastewater treatment service taking into account the appropriateness and efficiency of existing plants equipment and, consequently, evaluating economic incentives. The proposed procedure takes into account both wastewater treatment demand and quality of wastewater treatment service offered to citizens. Input data, provided by the National Institute of Statistics (ISTAT), were elaborated in order to define appropriate parameters, with a multi-criteria analysis being used to define the new performance indicator. The applicability of the proposed procedure was verified considering all the 8 Southern Italy and Island districts (Abruzzo, Molise, Campania, Apulia, Basilicata, Calabria, Sicily and Sardinia) involved in the programme. The obtained results show that the quality of municipal wastewater may influence the calculation of the incentive amount. The performance indicators defined in this work might be conveniently extended to other contexts similar to the assessed geographical area (Southern Italy and Islands).

Integrated Management Spells Success for Medellin, Colombia's, Water and Wastewater Utility

The city of Medellin is the second largest urban area in Colombia. The state‐owned company, Empresas Públicas de Medellín E.S.P. (EPM), provides water supply and wastewater treatment services to more than 3.5 million people in the city and nine other smaller towns in the conurbation. EPM also provides public services other than water supply and wastewater treatment. Eduardo Cadavid Restrepo, director of the department of water management at EPM, described the current status, challenges, and future plans for the water supply and sanitation system in Medellin in this interview (conducted by e‐mail in Spanish and later translated to English) with Andrea Diaz Osorio and Govindarajan Venkatesh. At the time the interview was conducted, Diaz Osorio was a student in the master's degree program at the Norwegian University of Science and Technology (NTNU) at Trondheim, Norway. Venkatesh is a postdoctoral researcher in the department of hydraulic and environmental engineering, also at NTNU.

Catch and Release Strategies: Using Available in-Plant Storage for Wastewater Peak Flow Attenuation

Catch and Release Strategies: Using Available in-Plant Storage for Wastewater Peak Flow AttenuationThe City of Los Angeles' Bureau of Sanitation provides wastewater collection, treatment, and disposal services for approximately 4 million residents within a 600-square-mile service area, including 29 contract agencies outside the City. The City's more than 6,700 miles of public sewers that can convey about 500 million gallons per day (MGD) of flow to the City's four wastewater treatment and water...Author(s)Fernando F. GonzalezDavid MoeringRegidia MayrenaRowena LauAli PoostiAdel HagekhalilSourceProceedings of the Water Environment FederationDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jun, 2013ISSN1938-6478DOI10.2175/193864713813504421Volume / Issue2013 / 1Content sourceCollection Systems ConferenceCopyright2013Word count874

Revenue Program Development: Sacramento Regional County Sanitation District and Sacramento Area Sewer District

Revenue Program Development: Sacramento Regional County Sanitation District and Sacramento Area Sewer DistrictThe Sacramento Regional County Sanitation District and the Sacramento Area Sewer District (the Districts) provide wastewater treatment and collection service to over 1.3 million users in northern California. The Districts' CFO relies upon a financial model to project monthly service charges, calculate impact fees and to provide supporting documentation for bond issues by each of the two Districts....Author(s)Robert GranthamMatthew MullenNicholas AlmeidaMarcia MaurerSourceProceedings of the Water Environment FederationSubjectSession 28: Two Shades of Green - Utility Management Sustainability & Finance SynergyDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2010ISSN1938-6478SICI1938-6478(20100101)2010:16L.1619;1-DOI10.2175/193864710798158210Volume / Issue2010 / 16Content sourceWEFTECFirst / last page(s)1619 - 1624Copyright2010Word count166Subject keywordsFinancial PlanningManagement ToolSustainabilityTechnology

A Tale of Two Joint Ventures: Jiangsu, China and Havana, Cuba: A Game-Theoretic Analysis of Public-Private Contracts in the Water Sector

Although there are few applications of game theory in the water governance literature, in this paper the author applies a game-theoretic framework to public-private partnerships in the water industry, with “water industry” defined broadly to include fresh water supply, wastewater treatment, and sanitation and sewarage services. In summary, the paper (1) provides a general overview of the most common forms of contractual arrangements or public-private partnerships in the water sector, (2) reviews two recent examples of public-private partnerships in the water sector -- one in the municipality of Havana, Cuba, the other in the Jiangsu province of China, and (3) presents a generalized partnership-game model and explains the possible application of this game-theoretic model to public-private partnerships in the water sector.