A low-lying coastal harvested bog in New Brunswick was inundated by a storm surge in January 2000 and commercially abandoned due to saltwater contamination. This study examines the hydrological processes controlling the seasonal and annual variability of salinity, and its long-term persistence. In the summer period there were two distinct hydrological zones characterized by differences in salinity, elevation, compressibility, soil moisture content, and water-table position. Low-lying sites had higher and more stable surface salinity concentrations (mean 5.7‰, coefficient of variation 0.57) than slightly elevated sites (mean 2.9‰, coefficient of variation 1.13) that experienced more evaporative enrichment. Salts permeated the peat column to a depth of at least 95 cm, with peak salinity occurring 35–75 cm below the surface. A persistent downward hydraulic gradient also indicated downward advective transport of salts, suggesting that over the long term salts will be leached out of the system.