NEW assessments of the durability of imported sand at Mt Martha Beach North may be required in the wake of last week’s storms. Thousands of tonnes of sand were trucked to the site in May 2010 after a series of storms had eroded the beach down to underlying clay and rock. A two-year study commissioned by the Department of Environment and Primary Industries estimated the beach was continually losing sand and would need renourishing in five to 10 years. “Nourishment sand has also been moved to the back of the beach, distributing itself along the cliffs. This increased berm height…