A former pharmacist turned land developer has the Mission Hills community on edge because of plans by his company, Elda Development, to construct new homes on Columbia Street. But Ahmed Eldahmy may get a dose of his own medicine because the land he purchased sits on an active fault line in the Rose Canyon Fault Zone. In 1972, the state of California Department of Conservation enacted the Alquist-Priolo Earthquake Fault Zoning Act, which regulates development projects being built near a fault line.