Colorado Springs Utilities took full control Monday of the NeuStream scrubber system used to remove sulfur dioxide emissions from the coal-fired Martin Drake Power Plant.
Neumann Systems Group Inc., which designed the system, had been completing installation and testing of the scrubbers.
Now, with new federal SO2 emissions standards kicking into gear in December 2017, Utilities workers will test the scrubber system in Drake Units 6 and 7 "to optimize performance," Utilities announced in a news release.
Neumann won a controversial single-bid contract for the SO2-reduction project in 2011.
Earlier this year, repeated tests on Unit 7 showed the capture of sulfur dioxide at more than 97 percent, with the first test removing 98.6 percent, said Dan Higgins, then interim energy supply manager.
Now the scrubbers are fully installed and working on both Units 6 and 7, and the SO2 that is removed is being turned into gypsum, which is stored near the Clear Spring Ranch Solar Array south of the city. Eventually, Utilities hopes to sell the gypsum, said spokeswoman Amy Trinidad.
The system's reported efficiency comes with a higher price tag than expected, however. Originally estimated to cost $111.8 million, the scrubber system's cost reached more than $178 million earlier this year, according to Utilities records obtained through a Colorado Open Records Act request.
That prompted a notice of a lawsuit against Utilities and the city, revealed last week, by downtown attorneys Robert J. Frank and Perry R. Sanders Jr. representing clean air activist Nicole Rosa.
They cited cost increases and consultant studies that "clearly indicate that conventional dry scrubber technologies" could have been used at Drake, a fact that "invalidates the 2011 sole source jurisdiction" used rather than competitive contract bidding.
But Higgins and others have said the NeuStream scrubber system developed by local physicist David Neumann is the best technology and least expensive option to eradicate the SO2 emissions.