Wiscasset Completes Capital Efficiency Plan™ Infrastructure Improvements
The Wiscasset Water District (WWD) is nearing completion of its final phase of water main replacements for the Town of Wiscasset, ME. In 2007, Wiscasset, a rural coastal town in Maine, embarked on a long-awaited infrastructure improvement program to replace the Town’s century-old waterlines. The Wiscasset Water District, engaged Tata & Howard’s services in 2010, to prepare a Capital Efficiency Plan™ (CEP), to identify areas to the Town’s water distribution system needing rehabilitation, repair, and/or replacement.
The Capital Efficiency Plan™ report which included hydraulic modeling, system criticality, and an asset management plan, provided the Utility with a database and Geographic Information System (GIS) representation for each pipe segment within their underground piping system. The CEP report also prioritized the water distribution system piping improvements and provided estimated costs to replace or rehabilitate the water mains.
In response to the CEP™ findings, the Wiscasset Water District retained the services of Tata & Howard, to perform design, bidding, construction administration, and resident project representation services for a series of water main projects.
Phased over 10 years, the plan included replacing 33,150 feet of 12-inch and 8-inch piping, installation of a water storage tank mixer, SCADA upgrades, and office landscaping improvements.
The final phase of water main replacements is scheduled to be completed during the summer of 2018 and will fulfill all the Priority I water main improvements identified in the 2010 CEP™ report. The projects were funded in part by a combination of USDA Rural Development grants (6 total) and loans (7 total), as well as coordination with the Maine Department of Transportation and Rural Development.
With the water main improvements nearing completion, the Wiscasset Water District has retained Tata & Howard to reevaluate its 2010 Capital Efficiency Plan™. The revised plan will update the water main inventory database and review additional recommended water distribution improvements.
Tata & Howard provided design and construction services for a new water treatment facility that houses a 1.2 mgd ultrafiltration system and completed a pilot test that consisted of an evaluation of two separate ultrafiltration technologies. Franklin Wells No. 1 and 2, located off Hayward Street in Franklin, Massachusetts were installed in the 1940’s with a combined safe yield of 1.2 million gallons per day. Due to high concentrations of iron and manganese in the groundwater, the wells were only used to meet peak water demands during the summer months. The construction of the water treatment facility recaptures the yield from these two sources. The water treatment facility consists of a main building which houses static mixers, ozone feed equipment, chemical feed equipment, prefilters, membrane filtration equipment, instrumentation and controls. Treatment consists of ozone oxidation followed by membrane ultrafiltration. The project was funded in part by the Massachusetts Water Pollution Abatement Trust through a low interest state revolving fund loan.
The overall treatment scheme is as follows: ozone injection, oxidation of iron and manganese in an ozone contact tank, prefiltration, treatment through two ultrafiltration membrane skids, chlorination prior to a clearwell, and fluoride addition prior to discharge into the distribution system. The plant is designed to recycle backwash water and membrane recirculation water to the head of the plant utilizing two decant tanks. Ozone is produced on site utilizing compressed air, while a LOX tank is available to allow for the production of additional ozone if required in the future.
Tata & Howard, Inc. was recently retained by the Town of Manchester-by-the-Sea to complete a Capital Efficiency Plan™ for the Town’s water system. The system was evaluated to identify areas of the water distribution system in need of rehabilitation, repair, or replacement, and to prioritize improvements to make the most efficient use of the Town’s capital budget. The study evaluates the existing water infrastructure including water transmission and distribution piping and appurtenances. In addition, water storage and supply needs were evaluated and prioritized. The analysis and improvements in this report are based on the Three Circles Approach for optimum capital efficiency, which combines hydraulic and critical component considerations with an asset management rating system to evaluate the condition of the water mains in the distribution system. Each circle represents a unique set of evaluation criteria for each water main segment. From each set of criteria, system deficiencies are identified. System deficiencies from each circle are then compared. Any deficiency that falls into more than one circle is given higher priority than one that does not. Using the Three Circle Approach, recommended improvements will result in the most benefit to the system. In addition, the Three Circle Approach allows us to identify any situations that mitigate a deficiency in one circle and eliminate a deficiency in another circle. By integrating all three sets of criteria, the infrastructure improvement decision making process and overall capital efficiency are optimized.
Recommendations included a siting study for a second storage tank, Phase I-III distribution system improvements, and the continuance of scheduled maintenance programs such as hydrant flushing, leak detection, and meter testing. The Town’s pavement management plan was also taken into consideration to best prioritize and coordinate utility work with roadway reconstruction.
A Capital Efficiency Plan™ was completed for the Town of Rowley in May 2017. The study evaluated the 45 miles of the Town’s water distribution system using the Three Circles Approach, which consists of a system hydraulic evaluation, criticality component assessment, and asset management considerations. From each set of criteria, system deficiencies were identified and a 20-year recommended improvements plan was provided. Recommended improvements consisted of water main replacement projects, a pumping capacity evaluation and well redevelopment study, an interconnection analysis, and a distribution static pressure evaluation.
A critical component assessment was performed for the water distribution system to evaluate the impact of potential water main failures on the system. The critical component assessment includes identification of critical areas served, critical water mains, and the need for redundant mains. Critical areas served were identified by the FDWD and include water department facilities, medical facilities, schools, and business districts. Critical water mains include primary transmission lines as well as water mains that cross over major highways, rivers, and railroad tracks. Factors that affected the decision to replace or rehabilitate a water main include break history, material, age, diameter, soil conditions, water quality, and pressure.