The primary objectives of this paper are to identify new considerations which should be incorporated into the planning of municipal water systems, and to assess the potential effects of these new considerations on traditional planning concepts. Generally, master water plans include analyses of supply and demand, descriptions of existing facilities, and proposed construction programs. Although many master water plans do consider the potential effects of future conditions, recent advances in technology and changing social concerns are beginning to exert a significant influence on the future course of water system development. Some of the new considerations which should be incorporated into municipal water system planning include the Safe Drinking Water Act, coordination with wastewater planning, wastewater reclamation and reuse, water conservation, environmental concerns, energy utilization, financial constraints, and changing public attitudes. In order to provide a responsive and effective framework for future planning of municipal water systems, the influence of these new considerations must be carefully evaluated in conjunction with traditional planning concerns.

New considerations for municipal water system planning

Water supply and electrical energy use are important topics at present, particularly in Sao Paulo (Brazil) where rising electricity prices and a changing climate are placing increasing strain on one of the world's biggest metropolitan area. This study uses information on dwellers socio-economic profile (SEP) and behavior to make adjustment in pumping operation schedule in a water distribution network system sector in Sao Paulo municipality together with long-term measurement of volume of water delivered, leakage, energy consumption, customer complaints due to water supply interruption, with the aim of improving efficiency. The findings suggest that dwellers SEP and behavior is suitable to adjust pumping operation schedule and that this procedure accounted for up to 25% of energy savings compared to baseline situation. With the adjustment it was also possible to reduce leakage flow in pipes, and most importantly the changes do not deteriorate service quality (efficacy) measured by customers complaints.

Assessing Energy Efficiency in Water Utilities Using Long-term Data Analysis

To supply the cities of Midland and Saginaw, Mich., with an average daily demand of about 50 mil gal, the Saginaw-Midland Water Supply System uses over 30 X 10H kWhr of electricity per year. In these days of "energy awareness," that is an impressive figure. How can such power costs be reduced? One means is to develop an Energy Efficiency Index (EEI, in this case, kilowatthours per million gallons pumped), monitor its variation with demand, and evaluate the effect of modified operating procedures on the EEI. If the index has been properly conceived, it can indicate means towards greater energy efficiency. In most instances, water transmission and distribution systems are relatively simple transport schemes, complicated by the hourly, daily, and yearly variations in demand. Thus operating procedures to supply demand, and, consequently, energy requirements, are also complicated by these variations. If peak to normal pumpage is compared, the energy and dollar differences can be quite significantand these peaks and valleys should be controlled.

William S. Howard

Papers

Analysis + Efficiency = Power Savings