explain why point-source pollution is easier to control than non point-source pollution. Point-source pollution is to control a single source, such as a factory, a water waster treatment plan, or a leaking oil tanker.This is easy because you know where the problem is coming from.resh water mainly comes from lakes rivers or a shallow zone beneath the earths surface and most of the water on earth is salt water which is found in the oceans. While the largest percentage of fresh water is from ice caps and glaciers. Fresh water is also found in rivers, lakes, and earths surface in aquifers.