Bala Consulting Engineers Inc. is pushing into Greater Washington with the acquisition of Meta Engineers P.C., a 40-year-old Arlington-based firm. This marks the fifth acquisition for Bala Consulting, a suburban Philadelphia-based company that sees itself eventually having a national platform. With the addition of Meta and its 17 employees, the acquisition brings Bala up to 200 people. Bala made its first acquisition in 2009 with Paul H.