The project entails a large open-pit mine, with the MACA contract worth US$230 million over seven years.
The Australian contractor will supply earthmoving equipment and conduct contract mining services at the gold project. The scope of works includes site preparation, drill and blast, load and haul and maintenance works.
The plan is for mobilisation to start in August and pre-production mining in October.
MACA's appointment follows Emerald signing a credit agreement with Sprott earlier this week for a $60 million debt facility.
Okvau is forecast to produce an average of 106,000 ounces at all-in sustaining costs of $754/oz.