Fighting against POLLUTION to Save Environment

Table 2 Composite sample Results

Note :- All parameters except pH are in Mg/Liter.

Table 3 CETP Results (11/01/2007)

Note :- All parameters except pH are in Mg/Liter.

Table 4 Results of DO Samples

Note :- All parameters except PH are expressed in mg/l.

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 of 560 mg/l. Hence, there is marginal drop in BOD level at the 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 downstream quality of river water 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 the confluence point is below 5 mg/l (BDL & 2.2 mg/l). Hence, dilution of pollutant is not proper at the confluence point.
8. The DO levels at downstream locations at 100, 500 & 1000 meters are more than 5 mg/l except once at 500 mtrs downstream (2.6 mg/l) in the evening time.
9. During low tide at 100 mtrs downstream of the confluence point, the river bed becomes visible and divides the river into two ditches. Due to this, during low tide, the right ditch of the river remains unutilized for dispersion of pollutants at Arey Khurd.
10. The visible river bed is linked to one island of approximately 150 meters in length. This island is about 280 meters downstream of the existing disposal point. Therefore, adequate dilution may not be available in this stretch.
11. During low tide at 500 meters downstream, the river bed opens and becomes visible.
12. At 1000 meters downstream, the quality of river water shows comparatively improved quality. During low tide, the river bed does not become dry and boats can travel in this stretch. The width of the river water is approximately 250 meters. The BOD levels observed are minimum 8 mg/l and maximum 15 mg/l. The DO levels observed are 6.9 mg/l and 7 mg/l, indicating availability of dilution.
13. Hence, this stretch may be examined for availability of adequate dilution/dispersion required for quality of effluent discharged from CETP, DO levels at various depths, velocity and flow of the river water, wave oscillation and river ecosystem to explore the possibility of disposal of effluent by NIO.
14. The BOD level in the outlet effluent observed on 11/01/2007 is 560 mg/l. Hence, one more aeration tank may be added in parallel for substantial reduction of BOD in CETP at Dhatav.
15. Map showing Kundalika river, existing disposal point, proposed disposal point and sampled points is enclosed.
16. 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.

Guidance
Dr. Dilip Boralkar, Member Secretary
Study Report of Kundalika River water at Arey Khurd treated effluent disposal point and down stream.