LAUREL, Md. (AP) -- Washington's Maryland suburbs have a large number of problematic concrete water mains that are prone to exploding without warning.
That's according to a review of 21 large utilities by The Washington Post (http://tinyurl.com/mad63zo ). The Post reports that the Washington Suburban Sanitary Commission has 350 miles of large concrete water mains, an inventory that's second only to Detroit's.
The mains are designed to carry high volumes of pressurized water and are supposed to have a 100-year lifespan. Many were installed in the 1970s, when less strict industry standards allowed for the installation of pipes that were more likely to break.
Nine of the mains have blown apart since 1996, including one that exploded this spring along Connecticut Avenue in Chevy Chase.
Information from: The Washington Post, http://www.washingtonpost.com
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