Danielle Roberts, T&D World
In 2015, when the New York City Department of Environmental Protection (DEP) announced the water supply to the city would be switched from the Catskill/Delaware watershed to a blend of the Catskill/Delaware and Croton watersheds, most New Yorkers simply shrugged their shoulders and went on their merry way making coffee, washing the dishes and taking long showers.
This was true of most New Yorkers, but not Consolidated Edison Co. of New York Inc. (Con Edison). On a peak day, the Con Edison system distributes more than 13 GW of electricity to an area of less than 800 sq. miles (2072 sq. km). Keeping the lights on in New York City includes heating and cooling that—in a good part of the lower two-thirds of Manhattan—operate on steam. Con Edison’s steam system is the largest in North America, larger than the next nine urban systems combined.
It turns out, when the New York City DEP modified the water source coming into the city, it changed the formula, or chemistry, of the water. The mineral content of the new mixture might have been fine for almost every normal application but not for boiling water and making steam by the megaton like Con Edison. As a result, the utility had to design customized electrical and mechanical water treatment solutions tailored to each of its steam plant locations. In particular, the steam plant on 60th Street presented numerous challenges.