AWWA IMTECH59646

North Penn Water Authority (NPWA), located in Bucks and Montgomery Counties, Pennsylvania, serves roughly 27,000 customers. NPWA oversees a system with 435 miles of water mains. The distribution system includes five pressure zones that receive water from 23 production well sources and a surface water treatment plant to meet an average daily demand of about nine million gallons (MG). Other facilities within the distribution system include seven water storage tanks and five booster pumping stations. NPWA and CH2M HILL, in conjunction with Optimatics, conducted a master-planning project that included the development of hydraulic and water quality models and optimization using genetic algorithms (GAs) to support the development of a cost-efficient and defensible Capital Improvement Plan (CIP). This master-planning approach was utilized to consider a wide range of improvement options to meet future demand conditions while obtaining the most cost-effective and hydraulically efficient plan. The careful construction of the master plan was important to NPWA in order to adequately serve a fully developed service area by the Year 2030. This service area growth and development is projected to increase the existing average daily water demand from approximately 9 MG to 13 MG under full buildout conditions, with maximum day demands reaching 19 MG. After constructing the calibrated hydraulic model, a modeling analysis was performed to identify deficiencies in the existing system and deficiencies that would be caused by increased future demand. Upon identifying deficiencies, NPWA worked with CH2M HILL and Optimatics to identify all possible solutions to the identified deficiencies. This resulted in approximately 315 existing pipe alignments that could be relined or upsized, 175 possible new pipe alignments, 8 potential new tank locations, 2 new booster station locations and 7 pressure zone boundary adjustments. Additionally, each of these improvement options was given a range of possible sizes. This wide range of variables resulted in a very complex analysis, obviously beyond the capabilities of a trial and error approach. The system improvements were optimized to meet established hydraulic performance criteria and minimize both operating and capital costs. The capital improvement projects identified and optimized by the GA analysis were confirmed by NPWA to be feasible and desirable improvements. After this confirmation, the optimized improvements were phased over a 25-year planning horizon to comprise a fully optimized CIP. Includes figures.