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Environmental Performance

- Environmental Goals and Policy
- Environmental Functions and Activities
- Environmental Performance and Improvement Targets
- Environmental Impacts Minimization and Mitigation
- Preventive Maintenance and Emergency Response
- Safety and Health



Environmental Goals and Policy

To reaffirm our commitment of providing the community with the best environmental service, we set the departmental environmental goals and policy as follows:

1. To provide and operate world-class sewerage/drainage systems and sewage treatment/disposal facilities to fulfil the growing needs of the local community and to contribute to the sustainable development of HK.
2. To implement sewerage and sewage treatment/disposal programmes in a professional manner, in partnership with other Government establishments including the EPD, and to meet the Water Quality Objectives for HK waters.
3. To implement drainage and flood protection programmes in a professional manner, to minimize flooding, and to provide protection to local inhabitants, property and the environment.

We are committed to being environmentally conscious in all our activities and services and endeavor to serve the HK community with the best of our expertise in safeguarding human health, protecting and preserving natural ecosystems, thus contributing to the sustainable development of HK.

We aim to continually improve the quality of our services, and to alleviate as far as practicable the impact that our facilities and sewerage and drainage systems impose on the environment of HK. To meet these objectives, we are committed to:

Adopting state-of-the-art clean technologies and pollution prevention measures;
Incorporating environmental considerations, whenever practicable, into our design, construction and operation in order to prevent pollution and maximize resource conservation;
Minimizing and mitigating environmental impacts arising from the construction and operation of our facilities; and
Complying with legal and any other requirements to which DSD subscribes.

We ensure that our Environmental Policy is communicated to all staff, our consultants and contractors, and is open to public scrutiny. Our staff are committed to upholding this departmental policy and receive the necessary training and resources to enable its implementation.


Environmental Functions and Activities

From a macro perspective, virtually all our work and activities are crucial to the well being of the HK community as they contribute towards an inhabitable environment in which people are protected from major flooding and all wastewater is properly conveyed, treated and disposed of. Significant direct and indirect environmental benefits can be derived from a better-preserved environment with less pollution. Nonetheless, during the construction phase, the public may encounter temporary adversities such as construction noise, odour and visual impacts etc. Furthermore, after construction, the day-to-day operation/maintenance of our sewerage/drainage system and treatment works would inevitably continue to exert a multitude of adverse impacts that must be alleviated.

Environmental Performance and Improvement Targets

Although many aspects of our work have environment implications, not all of them can be quantified easily or will necessarily be reported here. For instance, those intangible benefits that the presence and functioning of our sewerage/drainage systems and treatment facilities brings to the environment cannot practically be measured. On the other hand, some tangible benefits consequential to our treatment and disposal efforts were reported separately in the environmental report of EPD and will not be duplicated here. In any case, to reveal our environmental performance, a usable indicator would be the measured effluent quality of our 58 treatment plants (including 24 preliminary, 2 primary, 1 CEPT and 31 secondary plants) operated by us. As shown in Figure 4.1, the average effluent qualities of our CEPT and major secondary treatment works in 2001 were very close to 100% meeting the discharge requirements. Despite this notable achievement, as disclosed in our last report, the biological treatment-based Shatin STW has continued to suffer from overloading problems and occasionally encountered difficulty in achieving the treatment target. In view of this, corresponding upgrading works have been initiated and phase I works are due for completion in 2004.

Figure 4.1 Percentage Compliance in 2001 for CEPT and Secondary Treatment Plants


To ensure full compliance of our STWs both now and in future, we continue to implement the following tasks:

expanding our sewerage coverage and upgrading our treatment capacity as far as economically viable;
progressively upgrading obsolete and defunct facilities;
conducting inspections to uncover/remove illegal cross-connections which cause inflow of wastewater of unacceptable quantity and strength into our facilities;
regularly maintaining our plant and equipment to minimize occurrence of breakdowns;
devising and implementing Contingency Plans at all of our facilities;
working closely with other Government departments, especially the EPD, and implementing joint initiatives, e.g., the Beach Pollution Response Plan for responding promptly/effectively to pollution incidents; and
undertaking public education initiatives.

We consider it important to keep the public informed of the progress on our various programmes initiated for enhancing environmental performance. Major environmental objectives and targets, which encompass general management, construction and operation of the sewerage and drainage systems, as well as green management, are presented below.

In streamlining general management, we are committed to establishing and implementing Quality and Environmental Management Systems (QMS and EMS) progressively throughout the department. The acquisition of a QMS serves as the building block for an EMS. As an initial step, our laboratories have acquired HOKLAS accreditation in the summer of 1999. For the seven divisional ISO 9001 certifications that we plan to acquire, two have been completed successfully and on schedule in 2001. For the remaining five as well as the Corporate Certification, they are expected to be completed by the end of 2002. Regarding ISO 14001 certification, our Tai Po STW received the first EMS certification for DSD in February 2001. When more experience is accrued and resources become available, we hope to extend such certification progressively to other works of the department. A summary of the current management initiatives is shown in Table 4.1.

Objective Target Progress
Progressively implementing QMS and EMS throughout DSD To acquire ISO 9000 certification for the whole department by 2002

On schedule. 2 certifications completed in 2001 and 5 to be completed by 2002 respectively. acquisition of Corporate Certificate expected by 2002
To acquire ISO 14001 certification for the Tai Po STW by mid-2001 Successful completing of ISO 14001 certification for Tai Po STW in Feb 2001 and ahead of schedule
Table 4.1 Management initiatives for improving environmental performance

Regarding enhancement of the sewerage system, programmes have progressively been initiated and implemented. The current ones are summarized in Table 4.2 below.

Objective Target Progress
Continue to improve the sewerage system in HK Completing the East Kowloon SMP by 2001
Works completed satisfactorily and on schedule
Completing the North-West Kowloon SMP by 2003 On schedule
Completing the Tsuen Wan, Tsing Yi & Kwai Chung SMP by 2005 On schedule
Completing the Central, Western & Wan Chai West SMP by 2006 On schedule
Completing the Aberdeen, Ap Lei Chau & Pok Fu Lam SMP by 2006 On schedule
Completing the Tuen Mun SMP by 2007 Delay caused by continued villagers' objection. Programme under review by EPD
Minimize the number of recurrent blockage incidence Working towards minimizing complaints received per km of pipe (drain + sewer) to be equivalent to or below the current rate of 11.8 per km

Meeting target, the rate achieved for year 2001 is 10.2 per km
Minimize environmental impacts arising from blocked sewers Further improving on our Performance Pledge (currently 99% success rate) for responding to, and resolving blockage/complaints Meeting target, the success rate achieved for year 2001 is over 99%
Improve STW operational performance & levels of treatment Completing upgrading works at Shek Wu Hui STW (adding aeration/final setting tanks, digester and UV system) by late 2001 On schedule and completed in August 2001
Completing upgrading works at Shatin STW (adding treatment units, UV system and sludge dewatering plant) by 2009 First works contract commenced in early 2001. We anticipate completion of all upgrading works by 2007
Aesthetic improvement including landscaping at major STWs by 2004 On schedule. Several Cat. D items approved and works commenced this year
On-going review of STW operations to identify ways to resolve potential overloading problems and to minimize the occurrence of discharge non-compliance On-going. At Shatin STW, new air diffuser and sludge scraper installed in 2001 to alleviate overloading problem. Foam removal/suppression facilities added in early 2002 also as interim measure to improve effluent quality
Reduce energy consumption Ensuring our facilities all operate on appropriate tariff rate by 2000 All our facilities are now operating on appropriate tariff rate
Replacing electric water boiler by gas boiler using biogas as fuel at Tai Po STW On schedule. Works was completed in Nov 2001, resulting in annual electricity bill saving of $0.3 M
Replacement of aeration domes at Yuen Long STW by 2004 to enhance oxygen transfer efficiency and saving energy in turn On schedule
Modification works at Sai Kung STW to resolve sludge bulking problem and to reduce aeration/energy demand for chemicals On schedule and completed in early 2002
Reduce chemical consumption Initiating feasibility studies in 2000 to examine alternative disinfection systems at STWs to reduce the use of chemicals On schedule. At Stanley STW, full-scale trial on multi-points chlorine dosing method was conducted
Conducting a research and development programme on disinfection techniques to identify energy efficient, clean and cost-effective technologies On schedule. Alternative techniques including ozone, electrochemical and UV disinfection have been examined. Studies extended into year 2002
Table 4.2 Sewage system enhancement initiatives for improving environmental performance

Submerged UV lamps in operation

Regarding enhancement of the drainage systems, various programmes have been progressively initiated and implemented. The current major ones were summarized in Table 4.3 below.

Objective Target Progress
Visual enhancement of river training works, flood protection schemes and drainage channels Formalizing inventory and procedures to ensure the incorporation of environmental features into drainage and flood protection works by mid-2001 On schedule and completed in May 2001
Minimize the number of flooding black spots Reducing the number of flooding black spots through the implementation of major drainage improvement projects, including:
rehabilitation works at River Indus (Ng Tung R.) by end 2001;
Substantially completed and on schedule
rehabilitation works at River Beas (Sheung Yue R.) by end 2001;
Substantially completed and on schedule
main drainage channels for Ngau Tam Mei phase 1 by mid 2002;
Completion date delayed to mid 2003 due to inclement weather plus unsatisfactory contractor performance
phase 1 village flood protection for Pok Wai & Wang Chau by mid 2002;
On schedule
main drainage channels for Yuen Long & Kam Tin stage 2 by end 2002;
On schedule
village flood protection for Chuk Yuen Tsuen & Ha San Wai by mid 2003;
On schedule
West Kowloon drainage improvement works stage 1 & stage 2 (phase 1) by end 2004:
On schedule
village flood protection for Yuen Long, Kam Tin & Ngau Tam Mei stage 1 by end 2004;
On schedule
Village flood protection for Mai Po Lo Wai/Mai Po San Tsuen, Ma Tin Tsuen & Shui Pin Wai by end 2002;
On schedule
rural drainage rehabilitation scheme for River Ganges (Ping Yuen R.) by mid 2005;
On schedule
rural drainage rehabilitation for NWNT by mid 2005;
On schedule
Yuen Long, Kam Tin, Ngau Tam Mei & Tin Shui Wai drainage improvement stage 1, phase 1 by mid 2005;
On schedule
regulation of Shenzhen River stage 3 by mid 2005;
On schedule
eastern main drainage channel for San Tin by end 2005; and
On schedule
the Yuen Long bypass floodway by end 2005;
On schedule
Table 4.3 Drainage system enhancement initiatives for improving environmental performance

In green management, we recorded our efforts in the reduction of energy/paper consumption, reusing/recycling where possible and the avoidance of wastage etc. in the annual Green Manager's Report. Further to the general initiatives, noteworthy targets are highlighted in Table 4.4 below.

Objective Target Progress
Enhance the environmental awareness of the staff Reviewing & implementing environmental awareness and training programmes annually
Recurrent and ad hoc training have been provided annually to our staffs, e.g. Continuing Professional Development Course for engineering graduates. Engineers were also sent to attend courses such as ISO 14001, noise control, ecology & conservation etc.
Ongoing enhancement of staff awareness to conserve energy and to avoid wastage Through notices and Administrative Circulars, our staffs were constantly reminded to be environmentally conscious
Maximize our purchase of Green Products Reviewing purchasing policies in 2000 to identify opportunities for increasing the purchase of Green Products
Chlorine free paper that contain 50% recycled pulp has been in use since year 2000
Strive to meet HK's objectives on Indoor Air Quality (IAQ) at our premises Conducting regular IAQ audits, to ensure satisfactory air quality continues to be maintained at our premises
IAQ audits conducted once every two years
Monitor the environmental performance of our contractors Close monitoring of contractors through enforcement of contract terms plus regular appraisal of their performance
On-going. Requirements for contractors were stipulated in contracts and performances were monitored closely and appraised quarterly. Poor performance will receive warning and penalty
Enhance the environmental awareness of the general public Exhibition and open day for educational purpose
Exhibition and open day held in January 2002. Over 700 people visited the Stanley STW. Our professional staff briefed the visitors the operation of the STW. Positive feedbacks were received in the questionnaire survey conducted at the open day.
Table 4.4 Green initiatives for improving environmental performance




Stanley sewage treatment works open day

Environmental Impacts Minimization and Mitigation

Whilst all our activities are geared for serving the community and would produce beneficial impacts, the construction/operation/maintenance of our facilities inevitably brings about adverse environmental effects. They can be visual intrusion, noise or odour as well as loss of natural habitats etc. To alleviate these potential impacts of our activities, we have developed mitigating measures as shown below in Table 4.5.

Environmental Implication Activity Mitigation Measure
Visual impact Building pumping stations, treatment works & drainage channels
Designing facilities and channels to blend in with the environment
Planting greenery around treatment facilities and flood protection systems
Removal of blockages and debris
Noise impact Construction works
Adopting trenchless technology for pipe-laying works
Shielding construction equipment with acoustic screens as appropriate
Facility operation
Shielding noisy operations with enclosures or acoustic screens as appropriate
Using silenced plant & equipment
Adopting good housekeeping & maintanence measures
Odour impact Facility operation
Enclosing operations as appropriate
Using deodorizing techniques such as activated carbon, wet scrubbing and bio-filtering
Adopting good housekeeping & maintanence measures
Removal of blockages and debris
Land-use Building pumping station & treatment works
Constructing multi-storeyed buildings as appropriate to minimize land-use
Resource use Pipe-laying works
Careful selection of lining & material to prolong pipe longevity including reuse of rock aggregates as piping support, choosing epoxy resin lining and/or corrosion suppressant as appropriate
Preferential use of locally obtainable material to avoid pollution arising from distant transportation
Facility operation
Using energy efficient plant & equipment, such as those with variable speed drive, to conserve energy
Exploiting biogas generated by STW where practicable and using this as a supplementary power source
Reusing treated effluent where possible to minimize water consumption
Using on-line monitoring systems to gauge performance and ensuring optimal operation
Adopting volume-reducing techniques to minimize quantity of sludge to be disposed of at landfills
Water quality deteriorartion Construction & operation of channels and protection schemes
Minimizing the dispersion of waste and nutrients to the aquatic environment
Removal of blockages and debris
Loss and/or impairment of habitat
Planning through to implementation
Planting of vegetation to stabilize embankments
Grasscreting the slopes of drainage channels
Culturing mangroves
Reinstating fishponds
Conserving disused meanders
Wetland planting to make up for lost habitat
Table 4.5 Measures to minimize impacts and to enhance environmental performance

In addition, in compliance with the Environmental Impact Assessment Ordinance (EIAO), we conduct EIA studies for Designated Projects to identify and assess any potential impacts that may arise from our construction and operation activities. Mitigating measures can therefore be incorporated at an advanced stage into all phases of design, construction and operation works.












































Base line noise monitoring at Hennessy Road, Causeway Bay


Preventive Maintenance and Emergency Response

Figure 4.2 Number of complaints received per km of sewer/drain


To minimize sewer blockage, we carried out frequent inspections, clearance and maintenance of the sewerage system. To minimize flooding, we have implemented a preventive maintenance programme which consists of:

regular inspections of all river channels and drains by visual observation as well as closed-circuit television;
regular desilting works and removal of wastes and debris in river channels and drains; and
proactive repairing and upgrading of river channels and drains.

To ensure prompt response to any reported blockages in sewers/drains, a computerized database system has been established since 1997 that enables us to identify trends of blockages quickly and to prioritize effective maintenance activities. Figure 4.2 demonstrates that, notwithstanding increased public awareness in recent years, the numbers of complaints received per kilometre of sewer and drain both show a declining trend.


Safety and Health

Our department puts strong emphasis on safety at work in our sewerage and drainage facilities as well as our construction sites. The Safety Advisory Unit (SAU) was set up in 1994 to oversee and regulate all safety matters. This includes: preparing safety instructions and procedures, conducting safety inspections, compiling accident investigation reports and accident statistics, and organizing safety training courses for our staff and the site staff of our consultants and contractors. As our work adopts numerous types of construction techniques and equipment applied in widely different conditions, the risks encountered therefore are equally diverse. It is important that the information on safety legislation, instructions, procedures and good work practices that are relevant to our work are properly consolidated and documented for easy use by our staff. As such, the preparation of a contemporary departmental Safety Manual is deemed necessary.

Departmental Safety Manual
Following the changes in safety legislation and other safety requirements, the first departmental Safety Manual, which was prepared in 1994, has become obsolete. A new Safety Manual (Version 2002) was published in March 2002. The Safety Manual incorporates essential information regarding DSD's safety policy, safety objectives and strategy, safety legislation, instructions, procedures and work practices that are relevant to our undertakings. It serves as a comprehensive and handy guide to safety and health at work for the use of staff employed by the consultants/contractors engaged in DSD's works contracts who are responsible for the design, management and supervision of work, as well as DSD’s own workforce.

Safety Policy
The Safety Policy is the most important constituent of the Safety Manual. It sets out the commitment of our top management and our strategy to continuously improve safety and health at work, as well as the safety responsibilities of DSD's staff and our consultants/ contractors. The Safety Policy also spells out our safety targets for accident prevention, viz. for operation and maintenance activities carried out directly by DSD's staff. Our departmental aim is to eliminate serious accidents and to ensure that the accident frequency rate is below 10 reportable accidents per 1,000 staff per year. For construction and maintenance works undertaken by our contractors, we aim to eliminate fatal accidents and dangerous occurrences, as well as ensuring that the accident frequency rate is below 1.4 reportable accidents per 100,000 man-hours worked.

Safety Legislation, Instructions and Procedures
The Safety Manual lists all the regulations, ordinances, standards and codes of practice etc. that are relevant to safety and health at work. It also consists of safety instructions, safety procedures and good work practices for work on construction sites, sewage treatment plants, laboratories, offices etc. In addition, the Manual describes in detail the safety precautionary measures to be taken for outdoor work, work in adverse weather, work near or over water, work in confined spaces, work in gas risk areas, work at height, work on slope, work with electricity, welding work etc. Guidelines on fire prevention, safe handling of chemicals and hazardous substances, emergency preparedness, accident reporting etc. are also available for use of officers who are responsible for DSD's workplaces.

The appendices of the Manual contain lists of safety publications of various Government Departments and Occupational Safety and Health Council, safety training courses organized by various training institutes, accident reporting forms and safety-related circulars in force for the easy use of the readers.

Use of Manual
It is important that all personnel who are involved in DSD's undertakings should acquaint themselves with the provisions relevant to the work that they are responsible for. To this end, officers-in-charge of DSD's workplaces, namely sewage treatment facilities, pumping stations, depots, laboratories and offices, should ensure that at least one copy of this Manual is kept in the workplace and made known to all staff concerned. Similarly, Engineer's Representatives (ERs) who are responsible for DSD's works site should ensure that the copy of the Manual is kept in the site office for use by his/her site staff and another copy is available for use by staff of the contractor of the works contract.

The translation of the Safety Manual into Chinese is currently in progress and the Chinese version is expected to be available by early 2003. In addition, it is planned to upload the Safety Manual to DSD's internet web site. With our dedicated commitment to safety and the concerted effort of every staff, it is intended that the publication of this Manual will serve as a comprehensive and useful guide for the up-keeping of the safety and health at work on all of our undertakings, as well as the promotion of a safety culture amongst our department, our consultants and contractors.