According to the passage, what cannot be separated easily?

Directions: Read the following passage and answer the question on the basis of the content of the passage.
  
Waste management systems and market conditions, even at their best, are incapable of handling the growing amounts of waste globally. So, unless a new paradigm of global cooperation and governance is adopted, a tsunami of uncontrolled dumpsites will be the prevailing waste management method, especially in Asia. Despite the development of 'easy-to-repair' product design, long-lasting products or enhancement of reuse; a clear de-linking of economic growth from waste generation will still only be in its infancy. Even if sorting and recycling technologies are significantly improved and mechanised, a separation at source will be an inevitable prerequisite for an economic recycling schedule.