Optimizing the Structure and Scale of Urban Water Infrastructure: Integrating Distributed Systems

Large-scale, centralized water infrastructure has provided clean drinking water, wastewater treatment, stormwater management and flood protection for U.S. cities and towns for many decades, protecting public health, safety and environmental quality. To accommodate increasing demands driven by population growth and industrial needs, municipalities and utilities have typically expanded centralized water systems with longer distribution and collection networks. This approach achieves financial and institutional economies of scale and allows for centralized management. It comes with tradeoffs, however, including higher energy demands for longdistance transport; extensive maintenance needs; and disruption of the hydrologic cycle, including the large-scale transfer of freshwater resources to estuarine and saline environments.While smaller-scale distributed water infrastructure has been available for quite some time, it has yet to be widely adopted in urban areas of the United States. However, interest in rethinking how to best meet our water and sanitation needs has been building. Recent technological developments and concerns about sustainability and community resilience have prompted experts to view distributed systems as complementary to centralized infrastructure, and in some situations the preferred alternative.In March 2014, the Johnson Foundation at Wingspread partnered with the Water Environment Federation and the Patel College of Global Sustainability at the University of South Florida to convene a diverse group of experts to examine the potential for distributed water infrastructure systems to be integrated with or substituted for more traditional water infrastructure, with a focus on right-sizing the structure and scale of systems and services to optimize water, energy and sanitation management while achieving long-term sustainability and resilience

Optimizing operations of large-scale water supply networks: a case study

In this paper we propose a mathematical programming model for a large drinking water supply network and discuss some possible extensions. The proposed optimization model is of a real water distribution network, the largest water supply network in Flanders. The problem is nonlinear, nonconvex and involves some binary variables, making it belong to the class of NP-hard problems. We discuss a way to convexify the nonconvex term and show some results on two case instances of the actual network

Optimizing operations of large water supply networks: a case study

In this paper we propose a mathematical programming model for a large drinking water supply network and discuss some possible extensions. The proposed optimization model is of a real water distribution network, the largest water supply network in Flanders. The problem is nonlinear, nonconvex and involves some binary variables, making it belong to the class of NP-hard problems. We discuss a way to convexify the nonconvex term and show some results on two case instances of the actual network

Optimizing Sensing: From Water to the Web

Where should we place sensors to quickly detect contamination in drinking water distribution networks? Which blogs should we read to learn about the biggest stories on the Web? Such problems are typically NP-hard in theory and extremely challenging in practice. The authors present algorithms that exploit submodularity to efficiently find provably near-optimal solutions to large, complex real-world sensing problems

Ensuring Urban Water Security in Water-Scarce Regions of the United States

On December 11-13, 2013, The Johnson Foundation at Wingspread, along with partner ReNUWit, convened experts from different parts of the country to discuss the implications of chronic and episodic water scarcity on our nation's water infrastructure -- with the goal of moving beyond the "case-by-case" conversation to one about how cities can transform their infrastructure and management strategies. The resulting report identifies key principles of water security and explores components of good strategy and innovative water supply options while building the case for transformation

GPU-accelerated stochastic predictive control of drinking water networks

Despite the proven advantages of scenario-based stochastic model predictive control for the operational control of water networks, its applicability is limited by its considerable computational footprint. In this paper we fully exploit the structure of these problems and solve them using a proximal gradient algorithm parallelizing the involved operations. The proposed methodology is applied and validated on a case study: the water network of the city of Barcelona.Comment: 11 pages in double column, 7 figure

EOR as sequestration: Geoscience perspective

CO2 Enhanced Oil Recovery (EOR) has a development and operational history several decades longer than geologic sequestration of CO2 designed to benefit the atmosphere and provides much of the experience on which confidence in the newer technology is based. With modest increases in surveillance and accounting, future CO2 EOR using anthropogenic CO2 (CO2-A) captured to decrease atmospheric emissions can be used as part of a sequestration program.Bureau of Economic Geolog

Approximation of System Components for Pump Scheduling Optimisation

© 2015 The Authors. Published by Elsevier Ltd.The operation of pump systems in water distribution systems (WDS) is commonly the most expensive task for utilities with up to 70% of the operating cost of a pump system attributed to electricity consumption. Optimisation of pump scheduling could save 10-20% by improving efficiency or shifting consumption to periods with low tariffs. Due to the complexity of the optimal control problem, heuristic methods which cannot guarantee optimality are often applied. To facilitate the use of mathematical optimisation this paper investigates formulations of WDS components. We show that linear approximations outperform non-linear approximations, while maintaining comparable levels of accuracy

Developing an Agenda for Change for New Jersey's Urban Water Infrastructure

A water infrastructure crisis looms in New Jersey's oldest and largest cities -- cities that comprise nearly one-fifth of the state's population and are projected to absorb much of its future growth, and yet have combined sewer systems, which carry both sewage and rainwater, dating to the 19th century. These combined sewers include overflow relief points that, during rain events, often result in combined sewer overflows (CSOs), which discharge raw sewage into waterways. These combined systems can also result in raw sewage backing up into city streets, parks and homes, threatening public safety and health. Of the nation's 860 communities plagued historically by CSOs, just 84 have yet to upgrade their systems or adopt plans to address the problem. Twenty-one of those 84 communities -- one-quarter -- are located in New Jersey. Urban water infrastructure challenges in New Jersey are not limited to the 21 cities with combined sewers. Even outside the CSO cities, polluted stormwater runoff is the state's leading threat to water quality. Many sanitary and separate storm sewer pipes and water-supply lines in the state are more than 100 years old and showing their age. The annual statewide loss (via leaks) of treated drinking water is estimated at 20 -- 22 percent, with some distribution systems losing as much as 45 percent. Water main breaks and resulting service outages are a common aspect of life in many cities. In addition, preexisting flooding problems are being exacerbated by more intense rainfall events driven by climate change, and such events are expected to become more frequent in the future. Most notably, in October 2012 Hurricane Sandy dramatically exposed the vulnerability of many of New Jersey's urban water systems to flooding and other storm damage. Collectively, the problems stemming from aging and degraded water-supply, wastewater and stormwater infrastructure threaten to disrupt daily life, commerce and industry in these communities, and stunt their future economic prosperity.In May 2014, The Johnson Foundation at Wingspread partnered with New Jersey Future and the Geraldine R. Dodge Foundation to convene a diverse group of New Jersey leaders to develop an agenda for change aimed at catalyzing action to address urban water infrastructure challenges in the state. Participants represented diverse perspectives, including those of local, state and federal government; public and investorowned water utilities; economic and community development organizations; environmental groups; businesses; and finance and technology companies. The discussions focused on establishing guiding principles for improving urban water infrastructure in New Jersey's cities, identifying the driver for action and agreeing on priority action steps to stimulate progress on the issue. The convening resulted in two products:a three-page consensus "Agenda for Change for New Jersey's Urban Water Infrastructure", which captured the collective priorities of the group, andthis report, which elaborates upon the consensus document and presents The Johnson Foundation's synthesis of the broader range of information, insights and ideas shared during the convening