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Introduction
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| 1. |
This Circular outlines the procedures to be followed in all works, both public and private, which involve the marine disposal of dredged mud. It explains the responsibilities of the Environmental Protection Department and the Fill Management Committee. This Crcular is complementary to WBTC 6/92 "Fill Management". |
| 2. |
This Circular covers the disposal of dredged mud, whether uncontaminated or contaminated, in Gazetted marine disposal grounds or exhausted marine borrow pits. It does not cover the use of dredge mud to form reclamations. The Director of Environmental Protection will provide the criteria for the classification of contamination levels of mud. |
| 3. |
The contents of this Circular have been agreed by the Secretary for Planning Environment & Lands. It should be brought to the attention of all consultants engaged on Government and quasi-Government projects, and on major private projects which involve the dredging and subsequent marine disposal of mud. |
| Responsibilities of DEP and FMC |
| 4. |
Under the terms of the Dumping at Sea Act 1974 (Overseas Territory)Order 1975, both the Director of Environmental Protection (DEP) and the Director of Civil Engincering (DCE) and cited as delegated officers, DEP in respect of dumping at sea per se, and DCE in respect of dumping of material with the intention of forming reclamations. DEO is the Authority for the licensing and statutory control of marine disposal of dredged mud, but the Fill Management Committee (FMC), of which DCE is the Chairman, is responsible for management and allocation of the mud disposal capacity at different disposal sites.
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| 5. |
DEP controls dumping at sea by means of licences which are issued to the contractors who undertake the dumping. Licences are valid for specific periods of time, for specific quantities and types of waste carried by specific vessels, and they are subject to certain conditions. Failure to comply with a licence renders the contractor liable to legal action, and for repeated offences, to refusal of future licences. |
| Notificaqtion and Review of Disposal Requirements |
| 6. |
For projects with mud disposal requierments of 500,000m3 or more, it is the responsibility of the project department, consultant or developer to provide both DEP and FMC with a notification of marine disposal requirements at least eight months prior to contract tendering or dredging, whichever is earlier. Urgent, non-routine maintenance dredging does not require such prior notice. The notificaton, which should include proposals for sampling and testing the mud for contaminants, should be directed to the Principal Environmental Protection Officer of the Solid Waste Control Group of EPD (PEPO/SWC) and simultancously to the FMC Secretary in the Civil Engineering Department. |
| 7. |
Under the terms of WBTC 6/92, disposal of 500,000m3 or more of uncontaminated mud or any volume of contaminated mud will not be considered until the need for removal of the mud has first been demonstrated. The rationale for mud removal must therefore be provide at this time and directed to the Principal Government Geotechnical Engineer (PGGE) who acts as adviser to the FMC on this matter. |
| 8. |
For projects with uncontaminated mud disposal requirements of less than 500,000m3, PEPO?SWC will handle applications for marine disposal. |
| Determination fo Sediment Quality |
| 9. |
Within one month of receipt of a notification of mud disposal requirements, PEPO/SWC will confirm the sampling and testing programme to be adopted to evaluate the sediment quality. This will include: |
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(a)
(b)
(c)
(d) |
the number and locations of sampling stations,
the types of samples to be taken (eg, surface grab, vibrocore, etc),
the depths of sampling required, and
the types and numbers of tests to be undertaken. |
| Appendix 1 provides more detailed guidalines on likely requirements for sampling and testing of mud. |
| 10. |
The sampling and testing procedures are critical to the accurate evaluation of the sediment quality, and close supervision by the project department is therefore necessary. |
| 11. |
Upon completion of the sampling and testing, and at least three months prior to contract tendering of dredging, whichever is earlier, the project department, consultant or developer shall submit a formal Sediment Quality Report to PEPO/SWC. This Sediment Quality Report shall include records of the sampling and the results of the testing. |
| Allocation of Marine Disposal Site |
| 12. |
When PGGE has agreed the volume of mud to be removed, the allocation of mud disposal capacity will proceed as follows: In all Cases |
| 12.1 |
Within three weeks of receipt of the Sediment Quality Report, PEPO/SWC will advise the Secretary of FMC and the project department, consultant or developer whether open dumping is environmentally acceptable or whether the mud is contaminated and requires to be disposed of at a designated exhausted marine borrow pit. The criteria to be adopted for the classification of contaminated sediments are to be obtained from DEO who will be guided by these criteria in the issue of licences for dumping at sea. Any environmental conditions to be imposed at a later date when the dumping licence is issued to the contractor will be specified at this time. For contaminated mud, the need for special disposal arrangements, such as concealed disposal in borrow pits, will also be specified at this time. |
| Volumes of Uncontaminated Mud of 500,000m3 or More and Any Volume of Contaminated Mud |
| 12.2 |
Within six weeks of PRPO/SWC receiving the Sediment Quality Report, the FMC will finalise the disposal allocation, and the project department, consultant or developer will be informed. Any further conditions relating to management of the disposal area, such as the need for bathymetric surveys, will be specified at this time. |
| Volumes of Uncontaminated Mud Less than 500,000m3 |
| 12.3 |
Within six weeks of receipt of the Sediment quality Report, PEPO.SWC will finalise the disposal allocation, and the project department, consultant or developer will be informed. Any further conditions relating to the management of the disposal area, such as the need for bathymetric surveys, will be specified at this time. |
| Application for Marine Dumping Licence |
| 13. |
The contractor who will be undertaking the works must make a formal application to DEP for a dumping licence, and if the licence is granted, it will be the contractor's responsibility to ensure that the licence conditions are met to DEP's satisfaction. These licence conditions will include any FMC conditions relating to bathymetric surveys, etc. |
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(H B Phillipson)
Deputy Secretary (Works Policy)
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