We use three different chemicals in our plant process. Chlorine is added to neutralize pathogenic, or disease-causing organisms. After chlorination, sulfur dioxide is added to remove the chlorine before it is discharged into Paradise Creek. During the summer months we add a small amount of aluminum sulfate to coagulate, or capture, phosphorus that was not removed biologically in the treatment process. Phosphorus is an essential nutrient in plant growth yet excessive amounts can lead to eutrophication, an overabundance of plants and algae in a water body causing the depletion of oxygen needed for fish and other animals to survive.