Remarks:

1. Background quality of Kundalika river at the upstream of confluence point is showing BOD value of 10 & 14 mg/l during LT & HT wave. This is because of discharge of untreated sewage from Roha City at the Astami Bridge at about a distance of 5 Kms. upstream of effluent disposal point at Arey Khurd.
2. The river water quality at the confluence is deteriorated due to mixing and non provision of diffusers and improper dispersion of pollutant. The values of BOD observed are 220 mg/l during LT and 410 mg/l during HT. The effluent discharged from CETP on 11/01/2007 has the BOD value 560 mg/l. Hence there is marginal drop in BOD level at confluence point. The river water quality at the confluence point and the quality of effluent discharged from CETP shows inadequate dilution at Arey Khurd (disposal point )
3. The down stream quality of river at 100 mtrs shows improvement across its width. ( BOD - maximum 16 mg/l & minimum 9 mg/l)
4. At 500 mtrs. downstream the river quality is unaltered ( BOD - Maximum 15 mg/l Minimum 10 mg/l)
5. At 1000 mtrs downstream the river quality is slightly improved ( BOD- Maximum 15 mg/l Minimum 8 mg/l).
6. The DO level at the upstream location is observed as more than 5 mg/l
7. The DO level at confluence point is below 5 mg/l ( BDL & 2.2 mg/l ltrs. ). Hence dilution of pollutant is not proper at confluence point.
8. The DO levels at downstream location at 100,500 & 1000 meters are more than 5 mg/l except once at 500 mtrs. down stream (2.6 Mg/l) in the evening time.
9. During low tide at 100 mtrs. down stream of confluence point river bed becomes visible and divides the river in to two ditches. Due to this, during low tide right ditch of the river remains unutilized for dispersion of the pollutants at Arey Khurd. This visible river bed is linked to one island of approximately 150 Meters in length. This island is about 280 Meters down stream of existing disposal point. Therefore adequate dilution may not be available in this stretch.
10. During low tide at 500 meters down stream the river bed opens and become visible.
11. At 1000 meter down stream the quality of river water shows improved quality of river water comparatively. During low tide, the river bed does not become dry and boat can travel at this stretch. The width of the river water also at this point is approximately 250 meters. The BOD level observed are minimum 8 Mg/l and maximum 15 mg/l. The DO level observed are 6.9 mg/l and 7 mg/l which indicates availability of dilution. Hence this stretch may be examined for availability of adequate dilution / dispersion required for quality of effluent discharged from CETP, DO level at various depths, velocity and flow of the river water, wave oscillation and river eco system to explore the possibility of disposal of effluent by NIO.
12. The BOD level in the outlet quality effluent observed on 11.01.2007 as 560 mg/l. Hence one more aeration tank may be added in parallel for substantial reduction of BOD in CETP at Dhatav.
13. Map showing Kundalika river, existing disposal point proposed disposal point and the sampled points is enclosed.
14. Photographs showing the effluent disposal point, Kundalika river during high tide and low tide situation, islands in the river, visible river bed during low tide and points of monitoring are enclosed.