Question

In California treated wastewater is normally disinfected before being discharged to natural water bodies. Briefly state the health arguments for and against this practice.

Answer 1

Disinfection of wastewater before discharge into streams has both good and ill effects. These are as under:

Arguments in favor of disinfection:

1. Disinfection of water makes the water safe for use for both man and animal use

2. Very high quantity of micro-organisms in wastewater can lead to problems of various water-borne diseases via both in context with recreation water use and domestic water use.

3. Microorganisms in water are the cause of various diseases in humans. Pathogens commonly found in wastewater are E. coli, Salmonella, mycobacteria, Pseudomonas, Streptococcus, Shigella, and enteroviruses. Hookworm ova may be present in raw sewage.

4. High quantity of micro-organisms in wastewater can also disturb the aquatic life and its equilibrium.

5. Removes foul smell from water due to microbial activities.

Arguments not in favor of disinfection:

1. Chlorine disinfection can lead to the generation of disinfection byproducts (DBPs) which can be harmful to both humans and animals

2. High Chlorine dosage can spoil the taste and odor of water for household use.

3. Other disinfection processes other than the chlorination process are expensive and require high energy use ( UV light treatment).

4. Residual toxicity of the disinfection process is the major disadvantage of the disinfection process.