CalPortland Co will pay a US$350,000 fine for reportedly violating federal air-quality regulations.
The deal between CalPortland Co. and the US Environmental Protection Agency claims that the company did not obtain the proper permits for major modifications it made last year in its operations at its plant near Marana.
According to the EPA, the changes resulted in a significant net increase in coarse particulates.
But the fine, which EPA air-enforcement officer Doug McDaniel said is on the "high side" of those imposed by his agency, is only part of the deal. It also requires the company to choose between two options designed to reduce future pollution.
One involves CalPortland completing construction of what EPA calls a new "state-of-the-art" kiln in the next 42 months.
At that point, the company would have to shut down operation of four older kilns.