Managing the Environment

Greening and Enhancing Ecology

Sustainable Initiatives in Stonecutters Island Sewage Treatment Works’ Upgrading

In addition to enhancing the water quality of Victoria Harbour, DSD endeavours to seize opportunities to carry out pilot sustainable initiatives. The following initiatives are being implemented at Stonecutters Island Sewage Treatment Works (SCISTW) and they have established good examples for the industry.

Drain Responsibly - Introducing Sustainable Drainage Systems

Elements of sustainable drainage systems, such as the provision of bioswale, rain garden, permeable pavement, have been introduced to minimise the impact of excessive runoff. DSD has completed a feasibility study on the application of permeable pavement in Hong Kong and is conducting site trials at SCISTW.

Build Sustainably - Undertaking BEAM Plus Assessment

Building Environmental Assessment Method (BEAM) Plus Assessment is a comprehensive environmental assessment scheme for buildings recognised by Hong Kong Green Building Council. The Administration Building of SCISTW is undergoing the BEAM Plus process to assess its building performance and to explore ways for improvement through reducing carbon footprint during both construction and operation phases. This will also establish a model of “build sustainably” for other Sewage Treatment Works (STW) to follow suit.

Plant Smartly - Applying Soft Landscaping in Congested Environment

SCISTW is a congested and busy STW with multiple machinery operation and heavy vehicular traffic every day. Greening within SCISTW is hence no easy task and the success has demonstrated DSD’s commitment to sustainability. In the previous year, a total of 1,500 square metres of green roof have been constructed at SCISTW while more horizontal and vertical greening works are expected for the coming year.

Greening Works at Butterfly Valley Road Pet Garden

Opened in March 2014, the Butterfly Valley Road Pet Garden was an example of successful collaboration between DSD, the Leisure and Cultural Services Department and Sham Shui Po District Council in enhancing the local living environment.

The 7,000 square metres pet garden was built on top of the stilling basin of Lai Chi Kok Drainage Tunnel and beneath the viaduct of Tsing Sha Highway. This single piece of land serves the multi-purpose of flood prevention, transportation and recreation at the same time. To preserve water resources, the rainwater collected in Lai Chi Kok Drainage Tunnel will be used, upon suitable treatment, for non-potable uses such as for toilet flushing, irrigation and general cleansing within the pet garden, as well as for street cleansing by the Food and Environmental Hygiene Department in Sham Shui Po district.

The pet garden was planting with 75 trees and more than 50,000 shrubs/ groundcovers on 600 square metres of lawn areas. Besides timber benches and pet drinking fountains, the garden was also equipped with pet recreation facilities such as drainage pipes, weave poles and jumping hoops to nurture a joyful atmosphere.

Green Roofs for DSD Facilities

Roof greening can not only improve air quality, lower indoor temperature and reduce energy consumption of the building, but also enhance the building appearance and improve bio-diversity of the environment. In 2013-14, we have completed over 4,900 square metre roof greening works for nine facilities. Roof greening in other DSD facilities, including nine new facilities and three existing ones, are anticipated to be completed in 2014-15.

Green Roofs under Planning

Tseung Kwan O Preliminary Treatment Works - Screens Building & Inlet Pumping Station

We are planning for retrofitting green roofs at the Screens Building and Inlet Pumping Station of Tseung Kwan O Preliminary Treatment Works to improve their outlooks and to harmonise them with the surrounding environment. The relevant works are scheduled for commencement in mid-2014 for one-year construction period. With a total greening area of about 1,500 square metre, about 26,000 shrubs and 200 climbers will be planted on the roofs.

Green Roofs Recently Completed

Kowloon City Sewage Pumping Station Nos. 1 & 2

Kowloon City Sewage Pumping Station (SPS) No. 1 & 2 are located at the rim of Kai Tak Development Area. Aiming to achieve a sustainable design, the facilities have implanted the design concept of creating an urban oasis. The building surfaces are well integrated with green infrastructure elements such as pervious grass pavement, vertical greening, roof garden and rain garden to maximise the green coverage. The SPSs occupied an area of about 5,600 square metre, of which about 4,300 square metres are landscaping area. The concept of rainwater harvesting has also been introduced and the collected rainwater would be used for irrigation purpose within the facilties. The green roofs have adopted two different colours and textures to create a vivid geometry and to enhance the visual interest. With all these green elements, the SPSs provide a visual relief to the surrounding residents and enrich the urban biodiversity.

Vertical Greening

Study of Indoor Vertical Greening Systems in Stanley STW

The study of indoor Vertical Greening (VG) at Stanley STW has been carrying out in collaboration with the Chinese University of Hong Kong since January 2014. The purpose of the study is to evaluate the performance and the energy and maintenance requirements of various VG systems in an indoor environment. The study results will provide clues to practicability, limitation and design considerations for our future application of indoor VG systems, particularly for STW in caverns.

The study involved trial adoption of five different VG systems on an area of about 180 square metres with over 60 metres length on the cavern wall. Automatic irrigation and artificial lighting have been provided, and the substrate moisture, light intensity and other growth parameters are being closely monitored and recorded. Interim findings and recommendations of the study are expected in early 2015.