Almost four months after a deadly explosion halted work on a nearly $1-billion Connecticut powerplant under construction, developer Kleen Energy Systems LLC, Middletown, Conn., says the 620-MW gas-fired facility may be repaired and ready for operation next spring. But the U.S. Chemical Safety Board says it has found that “a disturbing number of companies” use the gas-blow pipe-cleaning process that led to the Feb. 7 explosion, which killed six workers and injured 50.

Gas blows remain the most common single practice to clean debris from powerplant pipes, according to the board. A recent survey by the board found the practice used routinely by 37% of the 62 gas-fired powerplants that responded, and, on occasion, by nearly two-thirds of the facilities surveyed.