Te Pūnaha Maimoatanga Wai o Ngāmotu

New Plymouth Water Treatment Plant

Source of water
Waiwhakaiho River.

Present capacity
65,000,000 L/day

Treatment

  • Coarse Material stepper screens at intake (Lake Mangamahoe)
  • Raw water conditioning (lime and/or CO2 addition).
  • Taste and odour removal (powdered activated carbon).
  • Coagulation (polyaluminium chloride).
  • Mixing (mechanical and static mixers).
  • Floculation (polyelectrolyte).
  • Clarification (upflow with gravelectric sludge removal cones).
  • Manganese/Iron removal (Lime for ph Adjust and Chlorine for oxidiation)
  • Filtration (rapid gravity filters).
  • Disinfection (chlorine gas).
  • pH correction for minimise corrosion in the reticulation. (CO2 and lime).

Clarifiers
Eight hopper bottom clarifiers fitted with plate settling tubes and gravelectric cones.

Filters
Eight rapid gravity sand filters filled with 600mm of anthracite over 400mm sand media.

The water treatment process