We propose to measure leptonic CP phase, after neutrino mass hierarchy is established, with an upgrade of the PINGU detector and using atmospheric neutrino flux. The upgrade, called super-PINGU, will require a few megaton effective volume at 0.5–1 GeV range to distinguish δ in the range π/2-3π/2 from 0 after 4 years of operation. The distinguishability (similar to significance) of measuring δ depends crucially on various flux, cross-section, event reconstruction (energy and angle) and flavor identification uncertainties. We explore effects of these uncertainties on the distinguishability of measuring CP phase and suggest possible ways to minimize their impact.