Unfair to compare one-stage UK example with Hong Kong waste plant

PUBLISHED : Friday, 28 March, 2014, 3:54am
UPDATED : Friday, 28 March, 2014, 3:54am

I refer to the letter by Emily Lam ("Concerns over new organic waste plant", March 24) and the opinion expressed in Lai See ("Digesting the price", March 15).

Ms Lam is right that despite food waste reduction efforts, adequate food waste treatment and recycling facilities are necessary to treat and recycle food waste.

Phase 1 of the organic waste treatment facility (OWTF) at Siu Ho Wan in North Lantau will recycle food waste into biogas for electricity generation and compost.

The compost produced shall be required to meet the compost and soil conditioner quality standards promulgated by the Hong Kong Organic Resource Centre, which is the compost standard adopted in Hong Kong.

Our pilot composting plant at Kowloon Bay has demonstrated that the compost products are of good quality. The compost quality produced by OWTF phase 1 can meet the centre's standards.

The average demand for compost in Hong Kong is about 20,000 tonnes per year, therefore, 7,000 tonnes of compost each year from the OWTF phase 1 could be absorbed.

As regards the issue of cost raised in Lai See, the scale, scope, type and site conditions for the food waste treatment plant in Hertfordshire, UK, are very different from those of OWTF phase 1.

The Hertfordshire plant is only a single-stage process using anaerobic digestion to produce electricity only. OWTF phase 1 is a two-staged process using anaerobic digestion and composting to produce electricity and good quality compost and is designed to operate every day throughout the year.

The Hertfordshire plant is located in an industrial area of approximately six hectares. OWTF Phase 1 has to fit into a very compact site of about 2.2 hectares and meet very challenging engineering conditions and stringent environmental standards.

The cost figure for the Hertfordshire plant refers to the construction cost only, excluding, for example, the costs of design, contract administration and supervision, and technology supply. The project estimate for OWTF phase 1 accounts for the total project cost of the design, construction and commissioning.

The Hertfordshire plant is privately owned and does not carry a public education function. The OWTF phase 1 will include public educational facilities.

As indicated in our food waste policy blueprint, we will continue to reduce food waste and develop modern large-scale organic waste treatment facilities in phases.

Elvis W. K. Au, assistant director of environmental protection