(ACE Paper 23/2002)
Proposed Water Quality Criteria
This paper seeks Members' views on the proposed Water Quality Criteria (WQC) to be adopted in the Environmental and Engineering Feasibility Study (EEFS) of the future options for the Harbour Area Treatment Scheme (HATS).
2. In November 2000, an International Review Panel (IRP) appointed by the Government to review the remaining stages of HATS recommended consideration of four alternative treatment and discharge options involving the use of Biological Aerated Filters1 (BAF) technology for treatment, deep tunnels for the sewage transfer system, and short outfalls for discharge. The IRP further recommended a number of studies and trials be conducted to evaluate these options before a final configuration for HATS should be selected for implementation.
3. One of the studies is the EEFS which would examine the environmental feasibility of the IRP options, the engineering viability of the sites proposed by IRP for installing treatment facilities, and updating of the estimates of the capital and recurrent cost for various options. The other trials/studies involve the pilot testing of BAF and other compact sewage treatment technologies suitable for use in Hong Kong, investigations into the most appropriate approach for future procurement of the HATS project, and studies of the capacities of the HATS Stage I facilities.
4. In May 2001, the Legislative Council Finance Committee approved $73.6 million for the Government to conduct the studies and trials. All studies and trials have commenced between November 2001 and April 2002 and are scheduled for completion by the end of 2003. We will then consult the community on all the viable options before deciding the way forward.
Water Quality Criteria
5. One key objective of the EEFS is to evaluate the potential impacts of the IRP options in respect of the long term environmental acceptability of discharging treated effluent into the receiving water bodies which are principally the harbour waters. It is thus necessary to develop water quality criteria (WQC) against which the impacts of various IRP options can be measured. For this purpose, we have developed initial proposals for WQC for discussion with the HATS Monitoring Group2. The EEFS consultants, Camp, Dresser & McKee International Inc (CDM) then refined these proposed WQC and set them out in a document entitled "Harbour Area Treatment Scheme: Moving Forward" (at Appendix I ) for consultation with stakeholders and interested members of the public. The document provides background information relevant to the selection of the WQC while the detailed technical proposals are contained in the annex to the document.
6. The document has been issued to the stakeholders listed at Appendix II and uploaded to the Internet at http://info.gov.hk/cleanharbour/ in early June. Stakeholders and the public are invited to give their comments on the proposed WQC by 27 July 2002.
7. Stakeholders have also been invited to a workshop on Saturday 22 June 2002 to offer their views on the proposed WQC. If necessary, the EEFS consultants may convene further meetings with individual stakeholders for discussion of specific comments. To ensure timely completion of the EEFS by end of 2003, we aim to finalize the WQC by September 2002 so that these criteria could be used for evaluating the environmental impact of various options on the receiving water bodies as proposed by the IRP.
8. Members are invited to comment on the proposed WQC for the EEFS. Members are most welcome to participate in the view-sharing workshop on 22 June and may register through the ACE Secretariat.
Environmental Protection Department
1BAF is an advance sewage treatment process characterized by flexible operations and compact size.
2A Monitoring Group chaired by the Secretary for the Environment and Food, with members drawn from the Advisory Council on the Environment, local members of the IRP, the Director of Environmental Protection and the Director of Drainage Services and the public, has been set up to monitor the trials and studies.