SEAWATER INTAKES AND BRINE OUTFALLS FOR 100 MLD MINJUR, 400 MLD & 150 MLD DESALINATION PLANTS FOR CHENNAI METROWATER

OBJECTIVES

  • Chennai metrowater has taken up the project of 100 MLD Desalination plant at Minjur, 400 MLD and 150 MLD of Nemmeli.
  • Indomer was asked to do various investigations on waves, currents, tide, geology of the seabed,
    location of the intake and outfall, modeling of dispersion of brine reject, CRZ demarcation, EIA
    preparation, engineering design of intake/outfall, method of launching and construction supervision.

SALIENT FINDINGS

• Indomer study facilitated to find ideal locations of seawater intakes and marine outfalls.
• Released brine reject undergoes dilution from 58 ppt to 35 ppt (ambient) within 150 m from the outfall.
• Presence of breakwater on the southern side at Minjur would induce more suspended sediments in the vicinity of intake.
• There are isolated rocky outcrops off Nemmeli.
• Appropriate pipeline launching methodology, method on control on bio-fouling and design for continuous gravity flow were provided.

Dispersion of brine reject of Minjur

Bathymetry off Minjur