integrated coastal zone management project west ... - Iczmpwb.org

186for implementation at Digha only to collect the surface run off and carry the water at a nonsiltingvelocity by gravity flow. Sankarpur, being sparsely populated and having a very fewhotels /lodges all surrounded by vast expanse of agricultural lands, has been left out of suchdrainage facility at present. Construction of storm water drains is an allowed item underCRZ regulation, since it is of the white water quality and mostly the high water during springtides coming inside the coastal area will be discharged through the storm water drains intothe sea.The existing surface drain passing by the side of beach embankment at Digha meant forcarrying storm water is charged with sullage water and effluents of septic tanks. The watercarried by the drains is thus highly contaminated with organic wastes and becomes septicwith high concentration of BOD 5 . This septic water gets discharged into the sea in violationof environmental safety. An attempt has been made to clean the water by effectivelyreducing the BOD 5 content by subjecting the urban liquid waste to the process ofenvironmental-friendly, cheap but widely accepted process of phyto-remediation. In fact,phyto-remediation was adopted as a pilot project at Digha to clean the water at a very lowcost, which produced a satisfactory result in increasing the dissolved oxygen so long as theproject at Digha was under operation. Later on due to lack of proper monitoring, the processfailed to achieve the desired result and at present is lying non-functional. It is now proposedin this project to reintroduce the process of cleaning the water through phyto-remediation atDigha on a much wider scale. A stretch of area measuring 300 meter by 50 meter along thebeach has been selected and reserved for phyto-remediation. The septic water from thesurface drain will be made to flow in a number of channels properly designed withimplantation of specific variety of plants to interact with pollutants and thereby to reduce thetoxicity and make the water suitable for discharging into the sea with BOD 5 concentrationless than 30 ppm. Sankarpur has been left out of the system of phyto-remediation for thepresent on the grounds mentioned earlier. Discharge of treated waste and effluent into thesea is an allowed item under Section-2 (v) of CRZ Notification, 1991.229. There is practically no planned drainage net work in Digha area. In some parts thereare road side open drains but it is very inadequate. A combined drainage sewerage systemexists in some stretches. The existing drains are insufficient to convey storm water duringmonsoon. The existing drainage system, therefore, needs immediate upgradation andimprovement. Accordingly, it has been proposed to lay surface drainage system for Dighaarea under DSDA. The drainage system will have several outfalls leading directly and