Synergistic benefits between stormwater management measures and a new pricing system for stormwater in the City of Hamburg.

Hamburg is a growing metropolitan city. The increase in sealed surfaces of about 0.36% per year and the subsequent increased runoff impacts on the city's wastewater infrastructure. Further potential risks to the drainage infrastructure arise also from effects of climate change, e.g. increased intensity and frequency of heavy rainfalls. These challenges were addressed in the Rain InfraStructure Adaption (RISA) project conducted 2009-2015 by HAMBURG WASSER and the State Ministry for Environment and Energy, supported by several municipal stakeholders. RISA addressed intensifying conflicts in the context of urban development and stormwater management at that time. Major results of the project are improvements and recommendations for adequate consideration of stormwater management issues during urban planning as well as new funding mechanisms for stormwater management measures. The latter topic resulted in the introduction of a separated stormwater charge based on the amount of sealed area connected to the sewer system of each property. For both undertakings - the RISA project and the introduction of the separated stormwater charge - a novel, comprehensive, digital database was built. Today, these geographical information system (GIS)-based data offer various scale-independent analysis and information opportunities, which facilitate the day-to-day business of HAMBURG WASSER and stormwater management practice in Hamburg.

International experiences in stormwater fee.

Stormwater management (SWM) includes a wide range of services aimed at environmental protection, enhancement of water resources and flood control. Local governments are responsible for managing all these aspects within their jurisdiction, but they often present limitations in generating revenues. Thus, many municipalities have been seeking a dedicated funding source for these programs and practices. This publication provides a brief overview of current legal issues associated with stormwater funding focusing on the most used method: fees. It is a successful mechanism to fund legal obligations of municipalities; however, it must have a significant value to motivate the reduction of runoff. Through literature, we found stormwater fees in Australia, Brazil, Canada, Ecuador, France, Germany, Poland, South Africa and the United States (USA). France had the highest average monthly fee, but this financing experience was suspended in 2014. Brazil has the lowest fee by m², comparable to the US fee. While in Brazil overall SWM represents low priority investments, the USA represents one of the most evolved countries in stormwater funding practices. It was noticed by reviewing the international experience that charging stormwater fees is a successful mechanism to fund the legal obligations and environmental protection.

Valuing information for sewer replacement decisions.

Decision-making for sewer asset management is partially based on intuition and often lacks explicit argumentation, hampering decision transparency and reproducibility. This is not to be preferred in light of public accountability and cost-effectiveness. It is unknown to what extent each decision criterion is appreciated by decision-makers. Further insight into this relative importance improves understanding of decision-making of sewer system managers. As such, a digital questionnaire (response ratio 43%), containing pairwise comparisons between 10 relevant information sources, was sent to all 407 municipalities in the Netherlands to analyse the relative importance and assess whether a shared frame of reasoning is present. Thurstone's law of comparative judgment was used for analysis, combined with several consistency tests. Results show that camera inspections were valued highest, while pipe age was considered least important. The respondents were pretty consistent per individual and also showed consistency as a group. This indicated a common framework of reasoning among the group. The feedback of the group showed, however, the respondents found it difficult to make general comparisons without having a context. This indicates decision-making in practice is more likely to be steered by other mechanisms than purely combining information sources.

Disparities in Water and Sewer Services in North Carolina: An Analysis of the Decision-Making Process.

OBJECTIVES: We examined the factors that affect access to municipal water and sewer service for unincorporated communities relying on wells and septic tanks. METHODS: Using a multisite case study design, we conducted in-depth, semistructured interviews with 25 key informants from 3 unincorporated communities in Hoke, New Hanover, and Transylvania counties, North Carolina, July through September 2013. Interviewees included elected officials, health officials, utility providers, and community members. We coded the interviews in ATLAS.ti to identify common themes. RESULTS: Financing for water and sewer service emerged as the predominant factor that influenced decisions to extend these services. Improved health emerged as a minor factor, suggesting that local officials may not place a high emphasis on the health benefits of extending public water and sewer services. Awareness of failed septic systems in communities can prompt city officials to extend sewer service to these areas; however, failed systems are often underreported. CONCLUSIONS: Understanding the health costs and benefits of water and sewer extension and integrating these findings into the local decision-making process may help address disparities in access to municipal services.

Economies of scale in the production of public health services: an analysis of local health districts in Florida.

OBJECTIVES: We examined the existence and the extent of scale and scope economies in the delivery of public health services. We also tested the strength of agency, population, and community characteristics that moderate scale and scope economies. METHODS: We collected service count and cost data for all Florida local health districts for 2008 and 2010, complemented with data on agency, population, and community characteristics. Using translog cost functions, we built models of operating efficiencies for 5 core public health activities: communicable disease surveillance, chronic disease prevention, food hygiene, on-site sewage treatment, and vital records. RESULTS: Economies of scale were found in most activities, with cost per unit decreasing as volume increased. The models did not, however, identify meaningful economies of scope. CONCLUSIONS: Consolidation or regionalization might lower cost per unit for select public health activities. This could free up resources for use in other areas, further improving the public's health.

[The necessity of new approaches to the elaboration of the projects for the sanitary (mountainous sanitary) protection districts around the therapeutic and health-promotion facilities, health resorts and their natural medical resources].

The international experience gained during the past two centuries indicates that the most efficient and rational way to ensure the protection of the territories occupied by the therapeutic and health-promotion facilities, spa centres, and health resorts together with their natural medical resources is to set up sanitary (mountainous sanitary) protection districts or zones along the perimeter of these territories. Beginning from 2000, numerous changes and amendments have been annually introduced in the Russian legislation intended to ensure efficacious control over the rational exploitation of the territories of therapeutic and health-promotion value and their natural medical resources. These initiatives have negative effect on the activities of these organizations and the quality of the services they are expected to provide. Taken together these effects lead to the degradation of the spa and health resort business. Bearing in mind the current conditions for economic activities, it is proposed, in contrast to the former global approach, to envisage in the aforementioned projects the establishment of the sanitary (mountainous sanitary) protection districts or zones and determine their borders based on the results of the assessment of their potential for the protection of therapeutic factors and other valuable resources. Equally important is the maximum reduction of the areas of the second and third zones taking into account their relevant objective characteristics. In certain cases, the protective district may coincide with the second zone. As far as the federal health resorts and large territories of special health-promotion value are concerned, some of them may have two or more sanitary (mountainous sanitary) protection districts. Both the owners and the users of these territories should be provided the necessary and sufficient possibilities for the rational nature use at the grounds and in the adjacent water areas suitable for the development of health resort business in the conditions guaranteed by the national legislation.

Modeling the hydrologic and economic efficacy of stormwater utility credit programs for US single family residences.

As regulatory pressure to reduce the environmental impact of urban stormwater intensifies, US municipalities increasingly seek a dedicated source of funding for stormwater programs, such as a stormwater utility. In rare instances, single family residences are eligible for utility discounts for installing green infrastructure. This study examined the hydrologic and economic efficacy of four such programs at the parcel scale: Cleveland (OH), Portland (OR), Fort Myers (FL), and Lynchburg (VA). Simulations were performed to model the reduction in stormwater runoff by implementing bioretention on a typical residential property according to extant administrative rules. The EPA National Stormwater Calculator was used to perform pre- vs post-retrofit comparisons and to demonstrate its ease of use for possible use by other cities in utility planning. Although surface slope, soil type and infiltration rate, impervious area, and bioretention parameters were different across cities, our results suggest that modeled runoff volume was most sensitive to percent of total impervious area that drained to the bioretention cell, with soil type the next most important factor. Findings also indicate a persistent gap between the percentage of annual runoff reduced and the percentage of fee reduced.

Cost of integrated vector control with improved sanitation and road infrastructure coupled with the use of slow-release Bacillus sphaericus granules in a tropical urban setting.

A field test of integrated vector control was conducted in a tropical urban setting with a combination of a floating, slow-release, granular formulation of Bacillus sphaericus and environmental engineering measures (renovation of roads, collective water pumps, and cesspool lids). The targets were Culex quinquefasciatus and Anopheles gambiae in the two biggest towns of Burkina Faso (West Africa). Within the intervention zone, water pumping stations were improved and the surroundings drained to prevent the accumulation of stagnant water. Roads were leveled and given either simple gutters on each side or a concrete channel on one side to drain runoff water. Garbage containers were installed to provide an alternative to the drainage channels for waste disposal. Septic tanks were modified so that they could be emptied without destroying their lid. This study showed that it is possible to implement mosquito control in a tropical urban environment with teams of young people rapidly trained to apply a biological larvicide without any tools other than an iron bar to lift cesspool lids. Environmental improvements were initially costly, but demanded little subsequent expenditure. Local inhabitants' committees were mobilized to provide people with information and monitor the efficacy of the measures. Compared with what people spent individually on mosquito prevention and malaria medicine, these measures were not expensive, but many expected the community to pay for them from existing taxes, e.g., for water treatment and disposal. The necessary funding and logistics require a municipal organization with neighborhood support, if the measures are to be effective.

Preventing bath water scalds: a cost-effectiveness analysis of introducing bath thermostatic mixer valves in social housing.

AIMS: To assess the cost-effectiveness of installing thermostatic mixer valves (TMVs) in reducing risks of bath water scalds and estimate the costs of avoiding bath water scalds. METHODS: The evaluation was undertaken from the perspective of the UK public sector, and conducted in conjunction with a randomised control trial of TMVs installed in social housing in Glasgow. Installation costs were borne by the social housing organisation, while support materials were provided by the UK NHS. Effectiveness was represented by the number of families with at-risk bath water temperatures pre- and post-installation, and the number of bath scalds avoided as a result of installation. Differences in the number of families with at-risk temperatures between groups were derived from the RCT. Cost-effectiveness was assessed and a series of one-way sensitivity analyses were conducted. RESULTS: Unit costs associated with installation were calculated to be £13.68, while costs associated with treating bath water scalds ranged from £25,226 to £71,902. The cost of an avoided bath water scald ranged from net savings to public purse of £1887 to £75,520 and at baseline produced a net saving of £3,229,008; that is, £1.41 saved for every £1 spent. CONCLUSION: It is very likely that installing TMVs as standard in social housing in new buildings and major refurbishments accompanied by educational information represents value for money.

The influence of the operational environment on the efficiency of water utilities.

Adjusting for the operational environment in studies of performance measurement is very important, otherwise the analysis may lead to unrealistic scores, especially when its influence on costs is high, such as in the water utilities. In this paper, we study the influence of exogenous variables on the water utilities performance by applying conditional efficiency measures based on the order-m method and its probabilistic formulation. We use a sample of 66 water utilities operating between 2002 and 2008, representing about 70% of the Portuguese population. Our research suggests that inefficiency of Portuguese water utilities is substantial for some utilities: several exogenous variables might influence it considerably. For example, regulation has a positive influence on efficiency but when drinking water supply and wastewater services are provided by the same utility or when the wholesale and retail activities are provided together, the performance is lower. The effect of ownership is inconclusive and the variables residential customers, water source, peak factor, and density of customers have a mixed influence on performance which varies according to their scores.

Economic viability and critical influencing factors assessment of black water and grey water source-separation sanitation system.

The black water and grey water source-separation sanitation system aims at efficient use of energy (biogas), water and nutrients but currently lacks evidence of economic viability to be considered a credible alternative to the conventional system. This study intends to demonstrate economic viability, identify main cost contributors and assess critical influencing factors. A technico-economic model was built based on a new neighbourhood in a Canadian context. Three implementation scales of source-separation system are defined: 500, 5,000 and 50,000 inhabitants. The results show that the source-separation system is 33% to 118% more costly than the conventional system, with the larger cost differential obtained by lower source-separation system implementation scales. A sensitivity analysis demonstrates that vacuum toilet flow reduction from 1.0 to 0.25 L/flush decreases source-separation system cost between 23 and 27%. It also shows that high resource costs can be beneficial or unfavourable to the source-separation system depending on whether the vacuum toilet flow is low or normal. Therefore, the future of this configuration of the source-separation system lies mainly in vacuum toilet flow reduction or the introduction of new efficient effluent volume reduction processes (e.g. reverse osmosis).

Zero subsidy strategies for accelerating access to rural water and sanitation services.

Community-Led Total Sanitation (CLTS) and Household-Led Water Supply (HLWS) are zero subsidy approaches to water and sanitation service provision that have been recently piloted in Zambia. The increases in access to sanitation and toilet usage levels achieved in one year under CLTS were far greater than any achieved in subsidised programmes of the past. Similarly, HLWS has shown that rural households are willing to invest in their own infrastructure and that they can increase coverage of safe water without external hardware subsidy. The promotion of self-sufficiency rather than dependency is a key component of both approaches, as is the focus on the development of sustainable services rather than the external provision of infrastructure. Zero subsidy strategies have the potential to deliver far more rapid increases in service coverage and higher levels of sustainability than the conventional subsidised approaches that predominate in low-income countries.

Cost effectiveness of centralised and decentralised storm water treatment.

As part of a research & development project commissioned by the Land of North Rhine-Westphalia's Ministry for the Environment and Nature Conservation, Agriculture and Consumer Protection (MUNLV) an examination is being carried out of the general possibilities for centralised and decentralised treatment storm water runoff to be discharged into (canalised) receiving waters and the costs ensuing from this. The examination of the different options is being carried out under real conditions, with the Briller Creek (Wuppertal/Germany) and Müggen Creek (Remscheid/Germany) catchment areas being used as models. The range of investigations deals with a comparison between 'decentralised, semicentralised, centralised' storm water treatment, centralised storm water treatment involving a separate sewer and parameter-specific pollution based storm water runoff control. In the framework of the research project each of the variants is to be elaborated and the costs are to be calculated so as to permit a comparison between the different system designs. In particular, the investigations are to take into account the actual requirements to be met by storm water drainage systems involving separate sewage systems.

From source to sink: "official" and "improved" water in Delhi, 1868­1956.

This article examines the making of a modern colonial city through the rhetoric of 'improvement' and 'progress' in relation to water. The reference is to the history of water in the city of Delhi and what may be called 'the first science of environment' in a colonial urban context, with a focus not so much on the 'extent' of water supply and drainage, and its (in)adequacy in the colonial city, as on concerns around the '(im)purity' of water, narratives of pollution, technologies of purity and the transformations they effected in a colonial context. In doing so it hopes to build upon a rich tradition of writings on urban water, its modernisation as also its location within a colonial regime, being suggestive of a framework in which we may consider water both as infrastructure and as environment, as much a network of pipes and drains as matters of pollution and well-being, as much a story of the search for and protection of the source as of the fate of the sink into which it ultimately flows.

Determining water sensitive urban design project benefits using a multi-criteria assessment tool.

The integration of urban water cycle management with urban planning and design is referred to as 'Water Sensitive Urban Design' or 'WSUD' in Australia; one of the key elements of WSUD is the management of urban stormwater. In early 2006, the Victorian Government released the Yarra River Action Plan, which allocated $20 million towards tackling urban stormwater pollution. To help ensure this money is allocated in an equitable and transparent manner across all metropolitan local governments a multi-criteria assessment tool has been developed. This paper presents an overview of the multi-criteria assessment tool developed and adopted for selecting WSUD projects that are eligible for funding through Melbourne Water's Stormwater Program. This tool considers three types of indicators: environmental, engagement (engagement with stakeholders and local government capacity building) and financial. Within each category, a series of indicators of different weightings are applied to score a project. Where initial concept designs do not meet the Program criteria, additional work is undertaken to refine and improve the project. The tool and its use are illustrated with a case study.

Upgrading of sewage treatment plant by sustainable and cost-effective separate treatment of industrial wastewater.

The Olburgen sewage treatment plant has been upgraded to improve the effluent quality by implementing a separate and dedicated treatment for industrial (potato) wastewater and reject water. The separate industrial treatment has been realized within a beneficial public-private partnership. The separate treatment of the concentrated flows of industrial wastewater and sludge treatment effluent proved to be more cost-efficient and area and energy efficient than a combined traditional treatment process. The industrial wastewater was first treated in a UASB reactor for biogas production. The UASB reactor effluent was combined with the reject water and treated in a struvite reactor (Phospaq process) followed by a one stage granular sludge nitritation/anammox process. For the first time both reactors where demonstrated on full scale and have been operated stable over a period of 3 years. The recovered struvite has been tested as a suitable substitute for commercial fertilizers. Prolonged exposure of granular anammox biomass to nitrite levels up to 30 mg/l did not result in inhibition of the anammox bacteria in this reactor configuration. The chosen option required a 17 times smaller reactorvolume (20,000 m(3) less volume) and saves electric power by approximately 1.5 GWh per year.

2009 Melbourne metropolitan sewerage strategy: a portfolio of decentralised and on-site concept designs.

The bulk and retail water companies of the greater Melbourne area are developing the 2009 Metropolitan Sewerage Strategy to provide sustainable sewerage services to 2060. The objective of the strategy is to establish long term principles and near term actions to produce a robust sewage management system for Melbourne. Melbourne's existing sewerage system is largely centralised and discharges to two major treatment plants. Several small satellite treatment plants service local urban areas generally more distant from the centralised system. Decentralised and on-site wastewater systems are options for future sewage management and could play a role in local recycling. A portfolio of 18 on-site and decentralised concept designs was developed, applicable to the full range of urban development types in Melbourne. The concepts can be used in evaluation of metropolitan system configurations as part of future integrated water cycle planning. The options included secondary and tertiary treatment systems incorporating re-use of water for non potable uses, urine separation, black and greywater separation and composting toilets. On-site and cluster treatment systems were analysed. Each option is described by its indicative capital and operating costs, energy use and water and nutrient balances. This paper summarises and compares the portfolio mix of decentralized and on-site options in Melbourne's context.

Estimating the costs of collective treatment of wastewater: the case of Walloon Region (Belgium).

This paper contributes to a better understanding of costs for collective wastewater treatment in the Walloon Region (Belgium). Based on a large set of data, unit costs to population equivalents are modelled. Considering investment as well as exploitation costs, the model includes not only wastewater treatment plants but also collector and sewage networks in an integrated approach at the technical basin level. Beyond this modelling, each type of process is analyzed independently in order to explore the structure of investment costs and their variation factors. Then, the model was used to forecast the upcoming expenses for 36 areas which are not yet equipped with collective wastewater treatment facilities. In light of these results, strategic choices for decision makers are discussed.

A balancing act: the consulting engineers' pragmatic view of process modelling.

Modelling: what do we know, what do we want to know and why? The practical application of models to real projects is often circular because these questions weren't asked prior to making the decision to model the plant under study. Modelling wastewater treatment plants can provide insight into the inner workings of the process that might not be attainable any other way, but is that added process knowledge always needed or necessary and what criteria does one use to determine the level of effort required? These complex modelling decisions require education, communication, and improved understanding amongst both modellers and clients. This submission explores the use of models by consultants for consulting purposes and the balancing acts (time versus knowledge and cost versus benefit) that the consulting engineer must manage when embarking on any modelling project.

Non-government organisation engagement in the sanitation sector: opportunities to maximise benefits.

Non-government organisations (NGOs) have long played a role in delivering sanitation services to communities in Southeast Asia and Pacific countries, particularly in rural areas. In contrast with large scale infrastructure focused initiatives, NGO programs commonly focus on building linkages between technical and social realms. Drawing on the breadth and depth of NGO experiences, there are opportunities for NGOs to play a greater role in the sanitation sector and to work in partnership with other actors including utilities and government agencies to ensure both 'hardware' and 'software' components of sanitation are built in to project design and delivery to maximise community benefits and ensure longer term system sustainability. This paper discusses these issues and considers how the contribution of NGOs to the sanitation sector in developing countries might be enhanced. The paper is based on recent research for the Australian Agency for International Development (AusAID) intended to guide investment in the water and sanitation sectors of Asia and Pacific partner countries, exploring the potential for increased NGO engagement. The paper presents findings of the research concerning NGO roles and approaches, discusses existing NGO activities in the sanitation sector in Vietnam and Timor Leste and identifies strategies for NGOs and for other sector actors including utilities and government agencies to maximise the benefits of NGO engagement in the sanitation sector.