A bankrupt chemical firm has been taken over by new management. On the property they found a 20000 m³ brine pond containing 25000 mg/L of salt. The new owners propose to flush the pond using fresh water containing no salts and the discharge the diluted water to the Atlantic Ocean. What flow rate of freshwater (m³/s) must they use to reduce the salt concentration in the pond to 500 mg/L within one year?