Under the new agreement, PNR data will be "depersonalised" after six months and would be moved into a "dormant database" after five years. However the information would still be held for a further 15 years before being fully "anonymised".
The PNR data will be stored in the US's Automated Targeting System (ATS). ATS is used to improve the collection, use, analysis, and dissemination of information that is gathered for the primary purpose of targeting, identifying, and preventing potential terrorists and terrorist weapons from entering the US..."
Link to Original Source