(Brookville, OH)--There is a massive economic development announcement for a company very close to the Whitewater Valley.  Six miles east of the Preble / Montgomery County line on I-70 is where construction is getting underway on a $920 million expansion of the DMAX plant.  It will add 1.1 million square feet to the existing facility.  Engine parts for GMC and Chevrolet pickup trucks will be produced there.  The project will result in the hiring of more than 700 employees.