Reports: Integrated wastewater planning has concrete benefits

Holistic analysis of a community's wastewater needs leads to cost savings and better service, according to a new report from Rocky Mountain Institute (RMI) and the U.S. EPA. A related report from RMI and the National Decentralized Water Resources Capacity Development Project (NDWRCDP) presents case studies that document the dynamics of the wastewater facility planning process.

The reports conclude that wastewater facility planning as conventionally practiced is too narrow in scope. It seldom addresses the full implications of wastewater decisions, and too often it gives decentralized options inadequate consideration.

Prepared by RMI for the EPA, "Valuing Decentralized Wastewater Technologies" presents a "catalog" of the economic advantages and disadvantages of decentralized wastewater systems relative to larger scale, centralized solutions. It also discusses techniques that can be used to place economic values on positive and negative impacts brought about by a community's choice of a wastewater system.

"One of the problems with traditional wastewater facility planning is that it doesn't generally consider the entire system and the costs associated with each part of the system," said water expert Richard Pinkham, formerly of RMI, now with Booz Allen Hamilton. For example, decentralized systems can avoid drawdown of water tables and reductions in stream base flow that can occur because of infiltration, inflow, and other alterations to a watershed water budget caused by sewers.

"Valuing Decentralized Wastewater Technologies" urges that the practice of facility planning be expanded to include a broader examination of all aspects of a proposed wastewater system. Indeed, the authors often use a different term, integrated wastewater planning, to indicate the kind of comprehensive planning and economic analysis communities need.

A second report, "Case Studies of Economic Analysis and Community Decision Making for Decentralized Wastewater Systems," prepared by RMI for the NDWRCDP (an EPA-funded research and education program), consists of case studies of various communities around the United States that struggled with wastewater infrastructure issues. The questions faced by the communities included how to manage dispersed wastewater systems, whether to replace septic systems with sewer systems, whether to extend sewers to growing areas, and determination of the optimum size of wastewater treatment facilities. Some of the communities studied "cluster systems" that serve groups of homes as an alternative to septic systems or sewers. The case study communities include: Mobile, Ala.; Paradise, Calif.; Charlotte County, Fla.; Johnson County, Kan.; Metropolitan Boston, Mass.; Lake Elmo, Minn.; Broadtop Township and Coaldale Borough, Pa.; and Washington Island, Wis.

The case studies examine how each community evaluated a range of issues in the wastewater facility decision-making process, or in some cases how issues came up after wastewater facility decisions were made. The report also includes a hypothetical analysis of the financial benefits of incremental capacity expansion using decentralized systems compared to infrequent, large investments in centralized capacity.

This report will be of particular interest to engineers, economists, planners and policy makers interested in both the broad issues and the intricacies of wastewater system planning. It will assist those who prepare wastewater plans and associated cost and economic analyses. In addition, many citizens and community leaders who are presently immersed in a wastewater planning process will find the report's discussions of interest.

Both reports are available as free downloads from RMI's Web site, www.rmi.org. For more information and to submit comments on these reports, contact Richard Pinkham at Booz Allen Hamilton, 5299 DTC Boulevard, Greenwood Village, CO 80111-3362, Tel (303) 221-7565, Fax (303) 694-7367, pinkham_richard@bah.com.

This article originally appeared in the 06/01/2005 issue of Environmental Protection.

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