A certain pesticide is fatal to fish fingerlings at a level of 0.50 parts per million in water. A leaking metal can containing 5.00 kg of the pesticide was dumped into a stream with flow of 10.0 L/sec moving at 1 km/hr. The container leaked pesticide at a constant rate of 5 mg/sec. For what distance (in km) downstream was the water contaminated by fatal levels of the pesticide by the time the container was empty?