Sridhar Vedachalam

Desalination in Northeastern U.S.: Lessons from Four Case Studies

While much of the desalination activity in the U.S is concentrated in southern and western states, the last decade has seen an unlikely location emerge for desalination – the Northeast. With precipitation often exceeding evapotranspiration, the Northeast generally maintains abundant surface and ground water resources that are readily available for human and ecological use. However, shortfalls in water supplies are leading some communities in the Northeast to consider desalination as an alternative water source. Presently, three desalination projects are in operation, while a fourth one is planned for construction. We review the conditions which led these locations to implement desalination projects including average and peak water demands, status of traditional water supply sources, topographical challenges and demographic changes. We identify financing, regulatory challenges and public support as factors critical to the initiation and success of desalination projects. Using information from the four projects, we propose a set of questions communities should consider to determine the viability of desalination projects vis-a-vis alternatives such as leak detection and infrastructure upgrades, conservation through water-efficient fixtures, and development of new surface and groundwater sources. An informed decision can help communities guarantee long-term supplies at optimal cost and minimal harm to the environment.

Who's the Cleanest of Them All? Sanitation Scores in Indian Cities

Urban India is struggling to provide adequate water and sanitation services to its citizens. Open defecation, insufficient wastewater treatment, and mixing of untreated wastewater with stormwater and drinking water supplies are contributing to a severe health and economic crisis. Recent government measures such as the Jawaharlal Nehru National Urban Renewal Mission and National Urban Sanitation Policy (NUSP) are steps in the right direction. We draw on sanitation scores awarded to 421 cities under NUSP to identify factors that explain the heterogeneity in city-level scores. Our estimates suggest the higher scores are partly a result of city location. Population is non-linearly associated with sanitation score. Consistent with recent literature, we show that increased presence of household toilets does not impact city-level sanitation outcomes. Further, smaller cities perform differently than medium and large cities, pointing to a need for customized policy prescriptions for different classes of cities, preferably designed by municipal governments.

Comment on 'Energy and air emission implications of a decentralized wastewater system'

In the article ?Energy and air emission implications of a decentralized wastewater system? published in Environmental Research Letters (2012 Environ. Res. Lett. 7 024007), Shehabi et?al compared a decentralized and a centralized system on the basis of energy use, greenhouse gas emissions and air pollutants, and claimed that economies of scale lower the environmental impacts from a centralized system on a per-volume basis. In this comment, we present literature and data from New York State, USA to argue that the authors? comparison between a small decentralized system (0.015 MGD) and a large centralized system (66.5 MGD) is unconventional and inappropriate.

Public–Private Partnerships and Contract Choice in India’s Water and Wastewater Sectors

Public provision of water and wastewater services in urban India has been a noteworthy failure, often providing service that ranges from non-existent to unreliable. Over the past decade, a number of reforms were undertaken that focused on infrastructure construction and urban governance, including broader use of public–private partnerships (PPPs). We examine a new data set of 163 water and wastewater PPP contracts initiated during 1999-2012 to study the determinants of a city’s decision to invite varying amounts of private participation though a PPP agreement. Cities with larger populations, better PPP regulatory environments, regional party rule, and lower sanitation scores are associated with higher levels of private participation through PPPs. Indian municipalities have often failed to engage the public before and during contract discussions, sometimes resulting in lukewarm public support for PPPs. Our findings highlight the role of cities’ socioeconomic indicators in determining the type of PPP contract undertaken.

Capital Investment and Privatization: Public Opinion on Issues Related to Water and Wastewater Infrastructure

Water and wastewater infrastructure (W&WI) in the U.S. is in need of immediate capital investments. Support from the federal government has declined significantly in the last two decades, forcing state and local governments to contribute a larger share. With increased decentralization of infrastructure decision-making, public opinion is playing an ever greater role. Questions on capital investment, privatization, and concern for W&WI were part of a national omnibus survey conducted in 2012. Demographic variables explained a small part of the variation in responses but were inconsistently significant across the issues, except for party affiliation, which was a significant explanatory variable for all three issues. Stated preferences through public opinion surveys, coupled with revealed preferences, can provide policymakers a broad understanding of public support for various W&WI policy alternatives. An informed electorate and a responsive government can together address complex challenges facing the water and wastewater sector in the country.

Media Discourse on Aging Water Infrastructure

Water infrastructure in the United States is aging. Budgetary constraints of federal, state and local governments have resulted in the delay or deferral of critically needed investments. Infrastructure failures such as water main breaks are a daily occurrence in many cities across the U.S. Recent observations at the state and national level indicate that public opinion is asserting itself on public investment decision-making by elected leaders. We conducted a content analysis of print media articles during the period 1999-2012 on water main breaks (WMB), and water and sewer rate increases (WSR). Approximately 500 articles on each topic drawn from the LexisNexis news database were randomly selected for the analysis. Our analysis found that media coverage of water infrastructure is an episodic affair with little attention to ongoing issues. WSR articles contained more details and a focus on governance, while WMB articles addressed business concerns and were concentrated in older cities.

An Analysis of Sewage Discharge Reports in New York, USA

Overflows in the sanitary sewer systems due to factors such as pipe blockages and insufficient capacity are termed sanitary sewer overflows (SSOs). The USEPA estimates that 23,000-75,000 SSOs occur every year nationally in the United States. SSOs are largely monitored by state governments and local municipalities. In 2012, New York enacted the Sewage Pollution Right to Know (SPRtK) Act, which requires public notification of untreated and partially treated sewage discharges. With the passing of this law, New York joined 12 other states that have similar laws. As part of the SPRtk Act requirements, the New York State Department of Environmental Conservation has made available aggregated sewage discharge reports (SDRs) on the web. In this article, we make use of the SDRs to identify spatial and temporal patterns in sewage discharge incidents. The SDRs are strongly associated with the type of municipality, density and age of the treatment plant.