AIWTP –Environmental Impact Assessment Report        2019


Annexure 7-3: Estimated Suspended Sediments Generation Standards from Dredging
                            and Dumping operations

Estimations had been made in Assessment Manual for dredging and Reclamation,
MinistryofTransport, Japan for suspended sediment generation from dredging and dumping
operations is given below. These can be used for estimating the suspended sediments to be
generated fromdredging for construction and operation of terminal.


                                        SS generated by dredging or   SS generated by dredging or
Activity / Type of the Bottom           dumping of one cubic metre    dumping of one cubic meter
                                        of sandy material             of silt / clay
Pump dredging                           Kg/m3                         Kg/m3
Ordinary 4,000 PS1/                     (2) 2.2 – 4.5                 (2) 1.2 – 1.4
Ordinary 2,000 PS                       (3) 0.1 – 0.3                 NA
Low – pollution type 1,600 PS           NA                            (3) 1.2 – 1.6
Low – pollution type 800 PS             NA                            (2) 1.5 – 3.5
Grab dredging
Ordinary 8m3 bucket                     NA                            (2) 10 – 89
Ordinary 3 m3 bucket                    (1) 8.4                       (4) 12 – 84
Water – tight type 8 m3 bucket          NA                            (1) 3.5
Bucket dredger                          (1) 17                        (1) 56
Dumping
By grab bucket                          (11) 0.4 – 5.0                NA
From hopper barge                       (2) 2.4 – 5.2                 (5) 12 – 203
Note: Parentheses are the number of times of observations

NA: Not Available

1/: Capacity   of pump in Horse Power

Source: Assessment of the Environmental Impact of Port Development, United Nations, New York, 1992




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