Grantee Research Project Results
Final Report: Multi-Objective Decision Model for Urban Water Use: Planning for a Regional Water Reuse Ordinance
EPA Grant Number: X3832204Title: Multi-Objective Decision Model for Urban Water Use: Planning for a Regional Water Reuse Ordinance
Investigators: Anderson, Paul R. , Elam, Jesse A. , Miller, Gary
Institution: Illinois Institute of Technology , Illinois Sustainable Technology Center , Chicago Metropolitan Agency for Planning
Current Institution: Illinois Institute of Technology , Chicago Metropolitan Agency for Planning , Illinois Sustainable Technology Center
EPA Project Officer: Aja, Hayley
Project Period: May 1, 2005 through December 31, 2008
Project Amount: $255,000
RFA: Collaborative Science & Technology Network for Sustainability (2004) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , Sustainable and Healthy Communities
Objective:
Urbanization and population growth present a challenge to urban water resources planning. Water reuse is one of several water conservation practices that can be part of this planning process. Although widely practiced in arid regions of the United States, water reuse planning in regions that enjoy abundant water supplies is rare. Northeastern Illinois is one such region, but projected increasing water demand points toward likely future water shortages. Water reuse implementation in NE Illinois, however, faces obstacles such as low municipal water rates, high capital cost of urban reuse implementation, and limited public acceptance.
The purpose of this research was to address these obstacles through a comprehensive study of the Illinois water diversion from Lake Michigan, including the subsequent allocation, use, disposition, and reuse practices. From this information we developed a methodology for water reuse planning in the Chicago region. The methodology includes a projection of future water shortages, reuse water availability analyses, and a way to identify and prioritize potential water reuse applications. The result is a decision support system to optimize allocation of urban water resources, integrate a water reuse system, and minimize the overall cost.
Summary/Accomplishments (Outputs/Outcomes):
Key results from this project are highlighted in the following paragraphs. More complete descriptions can be found in the publications identified in a subsequent section of this summary report.
- The Greater Chicago area could face municipal water supply shortages as early as 2016. If current trends continue, by 2030 the municipal water demand in Cook County, IL could exceed the supply by an amount ranging from 182 to 396 million gallons per day (MGD).
- The biggest barrier to implementing a treated wastewater reuse system in the City of Chicago is cost. Two of the most important economic issues to consider are the cost of municipal water and the cost of installing a secondary distribution system to supply treated wastewater.
- Municipal water in the City of Chicago is a bargain; at about $1.33 per 1,000 gallons (2006 and 2007 rate) it is among the least expensive in the nation. Unfortunately the low cost of municipal water presents a barrier to developing wastewater reuse systems.
- Pipeline installation accounts for about 90% of the cost of installing a secondary distribution system. Depending on the degree of existing development, pipeline installation costs range from $75 to $200 per foot of installed pipe.
- Although it is not appropriate for every application at every industry, it makes sense to plan treated wastewater distribution systems with industrial users in mind. This approach is especially important in urban settings where industries are often major water users, industrial users can be located relatively near wastewater treatment facilities, and – in contrast with irrigation applications – industrial demand need not be seasonal. In addition, potential ecosystem and human health risks associated with pharmaceutical products and by-products in treated wastewater are probably of less concern in industrial reuse applications.
- Spatial relationships play an important role in planning water reuse and secondary distribution systems. Where clusters of potential industrial (and other) users exist near a wastewater treatment plant they can substantially reduce the cost of a treated wastewater reuse project.
- Hydrologic footprints can be a useful economic development and water resources planning tool. We defined the hydrologic footprint as a measure of an industry’s interaction with water resources divided by the economic activity of that industry. The total interaction with water resources included direct demand, stormwater, cooling water associated with electricity demand, supply chain direct demand, and supply chain cooling water associated with electricity demand. (We estimated supply chain contributions for specific industrial sectors using the EIO-LCA model developed by the Green Design Institute at Carnegie Mellon). Among 35 unique industrial sectors, we identified two types of hydrologic footprints. In about 14% of the sectors (5 of 35) direct demand for water by that industry accounted for an average of 84% of the total hydrologic footprint. For most of the industry sectors (30 of 35, or 86%) the footprint was dominated (an average of 75%) by direct water demand in that industry’s supply sector.
- The Q-to-L ratio, a measure of the demand for treated wastewater divided by the length of the secondary distribution system, is an important part of the optimization work. Each cluster of potential users can have a unique Q-to-L ratio. High Q-to-L ratios, which lead to lower water supply costs, identify high priority clusters of users in the planning process. We considered three likely sources for treated wastewater in the Chicago area and estimated Q-to-L ratios of 5 (North Side WRP), 18 (Kirie WRP), and 306 (Bubbly Creek); the units used to express the ratio here are 103 gallons/mile. These values are slightly lower than the values we calculated for seven existing water reuse projects in four different states, which ranged from 145 to 1212 (103 gal/mi).
- A likely scenario for the Chicago area by 2030 is a water demand of 1358 MGD. We assumed that 50% of that demand could be satisfied using treated wastewater for nonpotable applications. The results of an optimization exercise indicate that 1271 MGD of the demand could be satisfied with conventional municipal water and the additional 87 MGD could be satisfied by supplying treated wastewater through 42 miles of a new secondary distribution system.
- Based on a sensitivity analysis, two of the most important factors affecting uncertainty are the applicable interest rate and the water demand per capita.
- Finding additional value in secondary distribution systems will help lower the cost barrier. Treated wastewater source heat pumps, which are an efficient way to address space conditioning and hot water supply, could play an important role.
Conclusions:
Major conclusions from this work are:
- Based on current demand, the Chicago area and northeastern Illinois are likely to face water shortages sometime between 2016 and 2030, by amounts ranging from 182 to 396 MGD.
- Treated wastewater reuse could be part of a comprehensive regional water resources planning effort to address future water shortages.
- Incentives and barriers that influence water reuse planning fall into the categories of technological, regulatory, policy, human health and ecosystem risks, public perception, and especially economic issues. Based on the current low cost of municipal water and the high cost of installing a secondary distribution system, there is little economic incentive to pursue large scale wastewater reuse in the Chicago area.
- Planning wastewater reuse networks based on local, secondary distribution systems for industrial users clustered near sources of treated wastewater makes sense. This approach addresses economic issues as well as many of the regulatory, policy, risk, and public perception issues.
- Better information on industrial water demand and water quality requirements could help water reuse planning efforts.
Journal Articles:
No journal articles submitted with this report: View all 28 publications for this projectSupplemental Keywords:
water reuse; optimization; secondary distribution, RFA, Scientific Discipline, Economic, Social, & Behavioral Science Research Program, ENVIRONMENTAL MANAGEMENT, Sustainable Industry/Business, Sustainable Environment, cleaner production/pollution prevention, Resources Management, Technology for Sustainable Environment, decision-making, Urban and Regional Planning, Economics & Decision Making, sustainable development, sustainable water use, water evaluation and urban planning tool, urban planning, wastewater, decision making, ecological design, barriers, environmental decision making, Urban water management, conservation, enforcement, water reuse ordinance, sustainable urban environment, environmental law, water conservation, Chicago, compliance costs, pollution preventionProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.