If the water has an NTU of >50, chlorination alone will not be effective; the water should be treated.
Considerations in water treatment:
- Find out if you are in an area where there are helminths or protozoa (Giardia and Cryptosporidium) that are resistant to chlorine, and ensure a fine mesh (4–6 microns) is added to the system. Some viruses may also require special treatment.
- Where possible, use gravity flow in the treatment system to avoid double pumping, and avoid constructing plants on flood-prone areas.
- Take great care when disposing of the highly toxic alum residual in the sedimentation tanks so as not to contaminate the ground- or surface-water.