water order. System expansion Given that conservation efforts brought demand well below the MWRA-defined "safe yield", and desiring to amortize over more ratepayers the fixed costs of large projects like the MetroWest Tunnel and Deer Island sewage treatment plant, the MWRA is seeking to add more wholesale water customers, including municipalities and properties straddling the border of its service area. At the same time, certain communities in Massachusetts are facing a shortage of available water due to population growth or other factors. From 2002 to 2009, the following municipalities and other customers have been added to the system: Stoughton, Massachusetts Avalon (private development on Danvers-Peabody border) Dedham/Westwood Water District YMCA (private customer on Salem-Marblehead border) Reading, Massachusetts Wilmington, Massachusetts Lead pipe removal MWRA and municipal water mains are made of concrete, steel, and iron, but as of 2016, about 5% of service lines (between the street and buildings, running from public to private property) in various municipalities were still made of lead. In 2016, during the Flint water crisis, the MWRA board approved $100 million in zero-interest loans for lead pipe removal. Each affected municipality is responsible for designing and operating its own program; MWRA estimates this funding will be enough to removal all lead service pipes from the entire system. MWRA has adjusted water pH since 1996 to avoid corrosion and leaching of lead from remaining pipes into drinking water. Planned expansions and upgrades Burlington, Massachusetts town meeting voted in 2018 to connect to the MWRA via Arlington, to make up for a partial shutdown of its Vine Brook Treatment Plant due to wells contaminated with 1,4 dioxane. Another vote to fund the second phase of construction is expected in 2021. In the meantime, Burlington gets MWRA water via Lexington if supplies drop to the point that a full outdoor watering ban is necessary (which happened during the drought of summer 2020). In June 2020, the Lynnfield Center Water District (one of two districts in Lynnfield, Massachusetts) reached its pumping capacity, due to a combination of drought and high residential water usage during the COVID-19 pandemic in Massachusetts. It started the process of making an emergency interconnection to the Lynnfield Water District, which is supplied by the MWRA. Because they have no alternative routes, City Tunnel, City Tunnel Extension, and Dorchester Tunnel cannot be taken out of service for more than a day for maintenance. Some of the valves