The city of Rockville, Md., has taken a proactive approach to meeting water quality regulatory compliance for its drinking water system. An unexpected notice of violation for exceeding the maximum contaminant level of total trihalomethanes (TTHMs) in 2008, however, caused the city to critically examine water quality in its water distribution system.
Each winter, water operators in northern climates face a range of challenges due to cold weather, including main breaks and equipment outages. While these emergencies come without warning, they are obvious and visible when they do occur. But in other parts of the water distribution system, cold weather can create a risk that is hidden from view: ice accumulation inside water storage tanks. Often, when operators realize they have a problem with ice in their tanks, it is too late—the tank’s interior is damaged or the wall is punctured.