In a local news report, an official from Ash Grove Cement Co. has confirmed that he believes the company’s Durkee cement plant will meet the US EPA’s NESHAP requirements by the deadline of 9 September 2015.
Minimising mercury emissions
The Durkee plant, located in Oregon, is one of the plants that caused some concern when the mercury limits were first announced, due to the unusually high mercury content in their raw materials. Ash Grove spent some US$20 million on emissions controls in 2010, reducing airborne mercury emissions by 95%, the report says. Further reductions may be necessary, but by comparison with the levels already achieved, these are minimal. In 2012, the plant produced 618 000 t of clinker and released 41 lb of mercury compounds via its air stack; this would need to be reduced to 34 lb at the same clinker production rate in order to meet the 2015 standards..
Meeting the challenge with technology
Plant Manager Terry Kerby told the Baker City Herald that the EPA’s ‘one size fits all’ rule has been very challenging for the plant, whose limestone contains up to 1100 ppb of mercury compared to many other plants where that content may be only 5 ppb. “We have been given an impossible goal,” he said. “We accepted the challenge…We have developed and created a solution and are proud we were able to do that.”.
The plant also has a vote of confidence from the Oregon Department of Environmental Quality’s Doug Welch, who told the newspaper, “I think what they have done (at the Durkee plant) is the best in the country – as far as what I have seen before”.
Edited from various sources by Katherine Guenioui