A Seattle K-8 public school built under state sustainability protocols had to be shut down after staff and students complained of annoying odors. When toxicology testing showed that high pH and moisture content in the concrete flooring had reacted with carpet adhesive and backing to produce methyl hexanol, a volatile organic compound, the school district had no choice but to carry out expensive repairs. Photo: Seattle Public Schools Carpet adhesive and moisture reacted. Opened in September 2009, the $37-million school struggled with complaints about the smell until closing in April 2010. The toxicology investigation confirmed the extent of the problem.
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.