Given the task definition and input, reply with output. Given a list of steps and an additional step, determine where the step fits into the original list of steps. A correct answer, correctly places the given step into the set of steps so that it creates a new plausible set of steps. Output must be formatted as 'After step n', where n is the step number after which the given additional step is to be inserted.

Steps: (1) The pollution negatively affects the water quality (2) The pollution negatively affects the health of plants and animals (3) The plants and animals have shorter, less healthy lives (4) The plants and animals do not reproduce very well (5) The number of plants and animals decreases over time (6) The quality of water gets worse and worse as there are no plants or animals to clean it (7) Eventually there is nothing living in the water and it is unusable
Where does the following step fit into the given list of steps: Pollution enters natural water sources such as rivers and lakes
Before step 1.