SECTION 4 RECOMMENDED DISTRIBUTION SYSTEM IMPROVEMENTS

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1 4.1 General SECTION 4 RECOMMENDED DISTRIBUTION SYSTEM IMPROVEMENTS Distribution system improvements, which have been organized and prioritized in this section, are forecasted and intended to be completed over a 10-year period. These recommendations are based on physical observations of the system, information from record information, DPW input and an analysis from the computerized hydraulic model of Milton s water distribution system. The system was analyzed to determine its ability to provide sufficient fire flow, pressure and water quality to all town areas. The analysis considered the hydraulic configuration, age, and reliability of the system s individual components. To consider the best levels of efficiency and economies, any proposed rehabilitation work should be combined with roadway, sewer and drainage projects whenever applicable. 4.2 General Distribution Improvements The following list itemizes recommended general improvements to Milton s Water Distribution System: 1. Water main deficiencies should be corrected by either cleaning and cement lining or replacing tuberculated pipes. Replacing tuberculated pipes should improve water flow, circulation and possibly decrease the formation of chloramines thus improving water quality. 2. Major pipe loop deficiencies should be corrected by connecting dead ends. This should improve water flow and circulation and possibly improve water quality by reducing the formation of chloramines. 3. Transmission lines should be kept in good condition to distribute water quickly and efficiently throughout the system. 4. Replace all 6-inch mains with a minimum of 8-inch mains to meet current AWWA standards. 5. Old iron or lead services should be replaced to assist in reducing unaccounted-for water loss, provide improved customer service and reduce maintenance. 6. Older, damaged or malfunctioning hydrants should be replaced with new, more reliable models. A hydrant replacement program will provide better, more reliable fire protection and reduce hydrant maintenance costs. 7. Closed gate valves, except division gates, should be opened and old or broken gate valves should be replaced. This will improve flow and circulation and provide more efficient main shutdowns in emergencies or during construction. Additionally, the opening and replacement of closed gate valves should eliminate dead ends and decrease consumption of disinfectants. 8. Unnecessary secondary mains should be removed or abandoned and disconnected from the primary mains. Services and hydrants connected to those mains should be connected to larger diameter mains where applicable. These improvements will simplify the system configuration, provide less head loss due to crossovers, decrease bottlenecks at pipe intersections and improve fire protection by eliminating confusion about which main a hydrant is connected to. 9. Update the water distribution system model on a regular basis to keep up with changes in the system. 10. Implement and maintain a unidirectional flushing program. 4-1

2 11. Implement and maintain a gate valve exercising program. 4.3 Prioritized Water Main Improvements Proposed water main improvements have been divided into three priorities. The first priority (highest) are water mains associated with the abandonment of the Canton interconnection water main. These improvements are necessary to ensure adequate water pressure and fire flow protection in the high pressure service area prior to the actual capping of the Canton interconnection water main. These improvements are scheduled for The second priority are water mains located in areas where there are potential water flow, water quality and fire protection concerns due to the age, size and water mains that have a history of breaks. Simulated hydraulic model runs results have indicated that these mains are heavily tuberculated and are in need of replacement. These improvements are scheduled for The third priority is water mains that are old, undersized and at the end of their useful lives. The replacement of these mains will improve water quality, water flow and fire protection. 4.4 Ten-Year Water Main Capital Improvement Plan Milton currently generates $365,000 in water capital funds annually through its rate structure and over a ten-year period has access to $500,000 annually through interest free loans through the MWRA Local Water System Assistance Program (LWSAP). Using an annual amount of $865,000 for pipe improvements, one possible scenario detailing year-by-year improvements for a 10-year period was developed as shown in Table 5.1. Costs for improvements are in 2014 dollars. Proposed costs include replacement of the existing water main, gate valves, fire hydrants, water services from the water main to the curb stop, a curb to curb overlay pavement restoration and a 20% contingency markup fee. The total footage for the Water Main Capital Improvement Program is 48,100 linear feet and a cost of $10,598,880. The 2015 budget of $2,813,040 is to cover the costs associated the proposed work is to ensure the water system can adequately meet domestic and fire flow requirements after the capping of the Canton inter-connection. The main water in Canton Avenue is an 8-inch cast iron pipe installed in This particular pipe is not only critical to servicing the domestic and fire flow demands of the areas along its path, it is a critical component of circulation, distribution and balancing of water stored in the systems water tanks. This pipe serves as one of the main feeds to the southern portion of the high pressure system. This pipe section is one of the most critical in the entire high pressure system therefore, it is programmed to be replaced in The main water supply to the areas east of East Milton Square is a 10-inch cast iron pipe under Adams Street which was installed in This water main is a critical component to the low pressure distribution system in this area. Therefore, it is recommended that this pipe be replaced very early in the CIP. It is also recommended that several other water mains be replaced after the Adams Street pipe is upgraded. These include the water mains in Washington, Antwerp and Franklin Streets. These water mains are scheduled to be replaced within the water programs. 4-2

3 The water mains in the Blue Hill Parkway and Brush Hill Road area are typically 6-inch cast iron pipe installed in These pipes are an important component to the low pressure distribution system in this area. Therefore, it is recommended that this pipe be replaced relatively early in the CIP. Therefore it is programmed to be replaced in In addition, several other water mains are programmed to be replaced including water mains in Belvoir Road, Cheever and Hudson Streets. The replacement of water mains will improve water flow and quality in the above areas. The CIP addresses the replacement of the water mains that serve as transmission pipes or pipes that bring water into an area. If water flow and/or quality persist, the Town should investigate the replacement of the secondary water mains in the area. 4-3

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7 4.5 Recommendations The proposed 10 year Capital Improvement Plan from year 2015 to 2024 is based on the current annual water improvements budget of $865,000 from which it can replace approximately 3,800 linear feet of water mains per year. The industry s general acceptance for the life of service for a water main is 100 years. Based on a 100 year life, by 2024, the end of this Capital Improvement Program, all water mains installed prior to 1925 should be replaced or rehabilitated. However, as shown in Table 1.3 (Water Main Installed By Decade) 130,574 l.f. and 81,228 l.f. of water main was installed in the 1910 s and 1920 s respectively. At the end of the Capital Improvement Program in 2024, the Town would be required to replace/rehabilitate all of the water main installed in the 1910 s and half of the water main installed in the 1920 s, or approximately 171,188 l.f.; which equates to approximately 17,552 l.f annually in each of the budget years from 2016 to At the current funding rate of $865,000 per year, the Town is able to undertake approximately 3,800 l.f. of water main replacement each year; about 20% of the replace rate that is necessary to meet even the least industry standard of 100 year old maximum pipe age! The current replacement rate indicates that the Town annually looses significant ground in the effort that is necessary for replacing pipes that have exceeded their useful life. Currently approximately 46% of the Town s water mains were installed prior to This means, if the Town s does not accelerate its current annual funding, which supports only 3,800 l.f. water main replacement/rehabilitation program, the system will continue to grow older and with and aging water system, it should expect to have a significant increase in water main breaks, lost water revenues, poor water flow and water quality issues. It is recommended that the Town increase the annual replacement/rehabilitation of water mains to approximately 15,000 l.f. each year over the next ten years. From year eleven to year twenty that amount could be reduced somewhat to approximately 14,000 l.f. per year. From year twenty-one to year thirty the amount could be reduced somewhat again to approximately 13,000 l.f. per year. After thirty years of committed pipeline replacement, the pace for future pipeline replacement can be reduced by more than half to approximately 6,000 l.f. per year for decades to come and beyond year thirty-one. To help reduce construction costs, the Town should investigate the cleaning and cement lining, and cured-in-place lining construction methods that can be applied to older and larger water mains (8-inches and larger). 4-6