DSD puts strong focus on environmental management in every project it delivers in order to make Hong Kong a livable city. In recent years, we actively campaigned for Blue-Green Infrastructure, emphasising the protection of river ecosystems in addition to environmentally friendly construction practices. These initiatives, alongside various emissions reduction and energy conservation measures at our facilities, are instrumental in promoting sustainable development in Hong Kong.
DSD actively implemented the concept of revitalisation of water bodies by building scenic environment with lush greens and pristine blues through Blue-Green Infrastructure, so as to offer more opportunities for the citizens to get closer to water bodies and learn to cherish natural resources.
Revitalising River Channels and Improving Ecologies
We experimented with various ecological conservation measures in our river improvement projects with a view to minimising environmental impact. We endeavoured to retain the natural habitat in rivers by preserving the natural course of the waterway, avoiding the use of concrete in constructing drainage channels, and keeping in-situ soil on riverbed in the design of our river improvement works.
Revitalising Nullahs in Urban Areas and Creating Public Spaces
DSD strives to integrate the concept of revitalising water bodies in large-scale drainage improvement works and planning drainage networks for New Development Areas, so as to build a better environment for the public. Given the scarce land resources in Hong Kong, revitalising river channels and nullahs in urban areas will bring vast swathes of accessible public spaces to the public for strolling, jogging and cycling right by the shore.
Green roof goes beyond architectural aesthetics; it also improves air quality, lowers indoor temperature and reduces energy consumption in buildings. In 2014-15, we completed roof greening for five of our facilities, and planted more than 570 trees and 370,000 shrubs.
Improvement Works at Pillar Point Sewage Treatment Works, Tuen Mun
Located south of Lung Mun Road in Tuen Mun, the Pillar Point Sewage Treatment Works (STW) incorporated various green elements during the design stage to beautify the environment of the STW and the surrounding.
Pillar Point STW occupies an area of around 44,000 square metres, in which over 30% (up to 15,000 square metres) is designated as landscape zone, covering almost 2,000 square metres of green roofs and 100 square metres of vertical greening, reinforced grasscrete pavement, and plantation areas.
We preserved 240 existing trees during the improvement works and planted 270 new trees across 11 native species within the landscape zone. We also planted about 229,000 shrubs to reinforce the green-screen effect and to visually blend the plant buildings with softer shades of green into the surrounding landscape.
Energy Management and Emission Control
DSD operates over 330 STWs and pumping stations which treat more than 1 billion cubic metres of sewage annually. Energy consumption of these facilities will lead to indirect emission of greenhouse gases and speed up climate change. In recent years, DSD has strengthened energy management and emission control to alleviate greenhouse effect.
We conduct regular carbon audits for our plants to identify the main sources of greenhouse gas and reduce the emissions accordingly by lower energy consumption, enhanced efficiency, use of renewable energy etc. We plan to extend carbon audit to more plants and construction projects in future.
Carbon Emission of 7 Major STWs of DSD
|Name of plant||Total emissions in 2013 (in tonnes-of-CO2 equivalent)|
|Stonecutters Island STW||39,589|
|Sha Tin STW||22,138|
|Tai Po STW||11,481|
|Shek Wu Hui STW||8,441|
|Northwest Kowloon PTW||1,219|
|Sai Kung STW||1,452|
Implementing Various Energy Conservation Measures
To conserve energy, we implemented various measures including the installation of combined heat and power (CHP) facilities at STWs, and replacement of florescent lamps in plants and outdoor lights with LED lamps and induction lamps respectively.
Use of Renewable Energy
Photovoltaic (PV) systems are installed in Yuen Long STW, Shek Wu Hui STW, Sandy Bay Preliminary Treatment Works (PTW) and Stonecutters Island STW to provide electricity for the plant equipment.
Energy Conversion from Biogas
CHP generators and Micro-turbine systems are installed in our facilities to generate electricity from biogas produced by the sewage treatment process so as to improve the overall energy efficiency of the process.
Use of Electric Vehicles
Electric vehicles (EVs) have zero emission and can help improve roadside air quality in Hong Kong. Through gaining more experience, we plan for a wider use of EVs in future.
Water Resources Management
With an escalating global shortage in water resources, DSD has proactively conducted pilot studies and trial projects in rainwater reuse and application of reclaimed water.
Happy Valley Underground Stormwater Storage Scheme - Water Harvesting System
“Happy Valley Underground Stormwater Storage Scheme (HVUSSS)” is the first project in Hong Kong which has adopted the use of state-of-the-art hydraulic modelling techniques to achieve flood control and environmental protection by improving accuracy in flood prevention designs, reducing energy consumption for water pumps and reducing construction costs and time.
Use of Reclaimed Water
Water reclamation is one of the initiatives in Total Water Management Strategy. It refers to replacing high quality fresh water with reclaimed water for non-potable purposes. At present, DSD purifies treated effluent with wastewater purification technology to ‘reclaimed water’ standards for non-potable uses.
Apart from incorporating green elements into our projects and sewage treatment facilities, we strive to realise green office at our Headquarters to improve the environmental performance of DSD. The implementation of relevant policies and measures helps raise the environmental awareness amongst our staff and promote a green culture across DSD.
DSD fully support the Government's green procurement policy. In 2014-15, we procured a variety of products complying with green specifications, including electrical appliances and office consumables.
It takes a joint effort by our colleagues to reduce power consumption in office through a proper use of lighting, air-conditioning and office equipment. We have recorded a progressive drop in electricity consumption. In 2014-15, we recorded a 6.8% reduction in energy consumption as compared with that in 2010-11.
We have set up recycling stations for printer toner cartridges, rechargeable batteries, paper, plastic, metal containers, etc; we have also actively promoted "paperless meetings" to reduce paper consumption by use of electronic appliances. In 2014-15, we recorded a decrease in paper consumption of approximately 29% compared to 2009-10.
Promoting Green Culture
Comprising a group of staff endeavoured in promoting environmental protection and green living, the Green Champions of DSD promotes environmental protection in daily work and encourages other colleagues to change their habits for a greener life. The Green Champions also held its second green farming competition in November 2014, in which attracted a total of 25 teams participating.