A new definition for sewage plant

January 21, 2018

Sewage plants:

Drainage Services Department Landscape Architects Sandy Tong and Stanley Hoi visit the Siu Ho Wan Sewage Treatment Works plant nursery twice a week.

Fresh perspective:

Green landscaping at Sha Tin Sewage Treatment Works has helped improve the district’s appearance.

Water purification:

Coix lacryma-jobi is a special plant that can filter nitrogen and phosphorous from water.

Vigorous and adaptable:

Celosia argentea has unique flowers and is good at adapting to poor growing conditions.

Enriched biodiversity:

The flowers of the Reevesia thyrsoidea tree can attract many butterflies and bees.

Download Video| Transcript

Voiceover:
The plant nursery at the Drainage Services Department's Siu Ho Wan Sewage Treatment Works is an unlikely home to a bustling ecosystem with 50 plant species. 

Drainage Services Department Landscape Architect Stanley Hoi:
The nursery is (aimed) at cultivating and propagating native plants species, such as trees, shrubs and riparian plants.

Voiceover:
Landscape architects, who are responsible for greening and landscape planning, design and management, visit the 2,000 sq m nursery, built in 2014, twice a week. They have discovered that a number of plant species can enrich the biodiversity of the facilities through their ability to attract bees and even purify water.

Drainage Services Department Landscape Architect Stanley Hoi:
This is Reevesia thyrsoidea. It is a native tree. The flower is very showy and the fragrance can attract many butterflies and bees. Another plant species which is Garcinia oblongifolia and it is also a native tree. You can see the fruit is in yellow colour which is the main food resource for wildlife. Also there is another two native plant species which is Celosia argentea and the other one is called Coix lacryma-jobi. This species, as you can see the shape of the flower, is very special. This is a very good plant because the plants can filter the nitrogen and phosphor in wastewater.

Voiceover:
Sandy Tong said having greening features in both new and old sewage facilities is a good thing for the community. The Landscape Architect, who joined the Drainage Services Department two years ago, said greening features at the Sha Tin Sewage Treatment Works, built in 1982, helped improve the district's appearance. She added the department has also installed 16 green roofs at various sewage treatment works in recent years.

Drainage Services Department Landscape Architect Sandy Tong:
(For) the landscape works in the Sha Tin Sewage Treatment Works, there are three aspects. The first one is at-grade planting, the second one is roof greening and the third one is vertical greening, to enhance the biodiversity of the site and also the surrounding environment. The second one is to provide a better visual impression to the neighbourhood and also the staff within the facility to enjoy better visual enjoyment.

Voiceover:
The Drainage Services Department will hold open days at the Sha Tin Sewage Treatment Works on January 27 and 28. The public can learn about the department's work on flood prevention, sewage treatment and greening works through a variety of entertainment and educational programmes. Admission is free.

A flowery fragrance fills the air at the Drainage Services Department's Siu Ho Wan Sewage Treatment Works, hardly the smell expected at a sewage plant.

But at this facility, which has the capacity to treat 180,000 cubic metres of sewage a day, the stench of wastewater is washed out by the fragrance produced by a teeming ecosystem made up of 50 plant species.

Trees and shrubs are housed at the treatment works' nursery where the department's landscape architects cultivate native plant species.

Responsible for greening and landscape planning, design and management, the landscapists visit the nursery twice a week and have found a number of plants help enrich the biodiversity of the facility through their ability to attract insects and purify water.

Biodiversity boost

When Landscape Architect Stanley Hoi steps into the nursery, he is greeted by bees and butterflies.

Many plant species depend on these insects to disperse pollen, a key ingredient in their reproduction.

"Reevesia thyrsoidea is a native tree. The flower is very showy and the fragrance can attract many butterflies and bees," Mr Hoi said.

Another plant in the nursery, Garcinia oblongifolia, produces yellow fruit, while Celosia argentea has uniquely shaped flowers and Coix lacryma-jobi can filter nitrogen and phosphorus from water.

Mr Hoi said all four species are well suited for the sewage facility, while Coix lacryma-jobi can also be planted on riversides.

Refreshing revamp

More than 15 green roofs have been installed by the Drainage Services Department at various sewage treatment works in recent years in an effort to beautify the facilities.

Landscape Architect Sandy Tong said greening features in both new and old sewage facilities is a good thing for the community.

She joined the department two years ago and said greening features at the Sha Tin Sewage Treatment Works, built in 1982, have helped the district's appearance.

"(For) the landscape works in the Sha Tin Sewage Treatment Works, there are three aspects.

"The first one is at-grade planting, the second one is roof greening and the third one is vertical greening, to enhance the biodiversity of the site and also the surrounding environment.

"(It) provide(s) a better visual impression to the neighbourhood and also the staff within the facility."

The Drainage Services Department will hold open days at Sha Tin Sewage Treatment Works on January 27 and 28.

The public can learn about the department's work on flood prevention, sewage treatment and greening works through a variety of entertainment and educational programmes.