What happens if the chlorine dosage exceeds the demand?

When the chlorine dosage exceeds the demand, the primary outcome is that there will be a chlorine residual in the water system. This indicates that after meeting the needs for disinfection and reacting with any contaminants present, there is still an excess of chlorine remaining in the water. This residual is crucial for ensuring ongoing disinfection as the water moves through the distribution system, protecting against potential microbial contamination.

Exceeding the demand does have implications for the formation of byproducts, which can occur when chlorine reacts with organic matter in the water; however, this is typically a concern when chlorine levels are significantly high and isn't the primary indication of an excess dosage. While maintenance might be impacted over time if high chlorine levels lead to corrosion of pipes or fixtures, this is not the most immediate result of exceeding chlorine demand. Similarly, while some chlorine is wasted if it's above demand and reacts too vigorously with available contaminants, the main focus is on establishing and maintaining a residual to ensure safety and efficacy in water treatment.