Because the real quench distance is only the minimum figure @ TDC (which is not the point of maximum risk), and there is measurable pumping loss getting those few molecules in and out of that small space, and as the clearance expands the loss is reduced.
Why is nonpoint source pollution potentially more harmful than point source pollution? a. Nonpoint source pollution disrupts the water cycle. b. Nonpoint source pollution is difficult to regulate. c. Nonpoint source pollution comes from more than one source. d. Nonpoint source pollution is more damaging to living organisms than point source pollution. Nonpoint source pollution generally results from land runoff, precipitation, atmospheric deposition, drainage, seepage or hydrologic modification.
Nonpoint Source Pollution Prevention - Identify and Prevent It. Pollution is an undesirable change in the physical, chemical, or biological characteristics of air, land, or water that adversely affects the living conditions for either humans or other living organisms. Water pollution is the impairment of the beneficial uses of water. Water quality can be adversely affected by direct and indirect sources. Direct sources are fairly obvious and include such practices as dumping waste and hazardous pollutants into streams. Indirect sources are called nonpoint source (NPS) pollution.