CED to brief district council again on dioxin treatment

The Government will go back to Kwai Tsing District Council (KTDC) to explain to members the standard and operation of the Tsing Yi Chemical Wastes Treatment Centre (CWTC) and the precautionary actions that will be taken to ease their concern over the treatment of the dioxin residues at the centre, a Civil Engineering Department spokesman said today (February 4).

The spokesman said the petition by some Kwai Tsing District Council Members early this morning might have been caused by certain misunderstanding among some District Council Members, including those who were not on the District Council during our previous consultations with it, about the standard adopted by CWTC.

"In order to clarify matters to show that the CWTC fully meets internationally acceptable standard and will safely treat the dioxin residues, we will explain the details to the District Council again shortly," the spokesman said.

He also said although the department curtailed the trial to avoid confrontation, the convoy had travelled a long distance from To Kau Wan to Cheung  Tsing Highway.  The delivery arrangements had been carried out in accordance with the plan and proved to be workable.

The spokesman stressed that the transportation had extremely low inherent risks. 

Notwithstanding the low inherent risk, extremely stringent precautionary measures is put in place for the transportation:

a) The residue is in solid form, non-volatile, insoluble in water and non-inflammable, and is kept in drums that comply with the United Nations' standard.

b) A dedicated route away from residential area is adopted.  It starts from North Lantau Expressway, Tsing Ma Bridge, Cheung Tsing Highway, Tsing Yi Road West, Tsing Yi Road and finally reaches CWTC at the southern side of the Tsing Yi Island.  

c) Transportation is scheduled to be undertaken after midnight subject to a safe speed limit, with escort vehicles from contractor and police in front and rear.   

d) An emergency response centre will be activated to deal with untoward incidents.

e) Transportation is conducted by a licensed chemical waste collector in full compliance with the Waste Disposal Ordinance.

f) A trial exercise to ensure smooth transportation before actual transportation of the real residues to CWTC.    

The spokesman said that KTDC members and the concerned green groups have been briefed about the transportation and incineration arrangement in detail before. 

In July 2003, KTDC set up a Working Group to monitor the transportation and incineration processes.  Since then, the Working Group held four meetings with government representatives on the arrangement for the transportation and incineration.

The Working Group also organised two sessions for government representatives to brief representatives of the oil and chemical industries in Tsing Yi south on August 21, 2003 and to brief representatives of Tsing Yi South West and North East Areas Committees on September 15, 2003. Copies of a leaflet were also given to them and local residents organisations.

As regard the treatment method, the spokesman said incineration was recommended in the relevant Environmental Impact Assessment Report, endorsed by the Advisory Council on the Environment and also approved by the Director of Environmental Protection under the Environmental Impact Assessment Ordinance, following extensive public consultation in early 2002," he said.

During the EIA study for the decommissioning of the former Cheoy Lee Shipyard, CED had assessed various options for treatment of dioxin residues that were generated after the dioxin-contaminated soil went through the thermal desorption process.  Both incineration and non-incineration technologies were examined for treatment of the residues. 

"Incineration at the CWTC was finally adopted as it was concluded to be the proven and very effective technology to treat dioxin residues and was in line with international practices." 

Non-incineration technology such as Based Catalyzed Dechlorination (BCD) was evaluated but not adopted because of its lower destruction efficiency (99.99%- 99.999%) in comparison with incineration (99.9999%).  BCD would also generate five times more by-product residues requiring further treatment, and would result in double-handling and potentially more secondary environmental impacts. 

BCD is an emerging technology (that is, one that is in the development and demonstration phase) without a long performance track record.

With adequate spare capacity and state-of-the-art technology including effective air pollution control devices, CWTC can effectively and safely decompose dioxins into harmless carbon dioxide and water vapour. 

The CWTC adopts the most stringent international standard for dioxin emission (i.e. less than 0.1 nanogramme per cubic metre).  The dioxin concentrations of the flue gas from the chimney will be subject to vigorous monitoring to ensure stringent emission standard is met. 

A performance test (trial incineration) will also be carried out to check the treatment efficiency of the residues at CWTC.  In accordance with the Environmental Permit condition, the test report will be submitted to EPD for approval. 

"No transportation of residues, except for the purpose of performance test, to CWTC for incineration will be allowed before EPD's approval is obtained," the spokesman said.

An Independent Expert Assessor has been employed to verify the effectiveness of the transportation and incineration processes, he added.

The spokesman urged members of Kwai Tsing District Council and other concerned group to resolve their differences through discussions instead of by taking drastic actions.

Ends/Wednesday, February 4, 2004