Chapter 16 Hazardous Waste Management

Issue Date: November 1, 2006 Issue Number: 3

D. Procedures for Disposal of General Chemical Waste Handbook

A. Introduction

This chapter provides details on the management of hazardous wastes at HKUST. It summarizes the types of waste which can be disposed of through the municipal sewer system and those which require segregation and disposal at approved hazardous waste disposal sites. It also specifies the roles and responsibilities for the implementation of this plan.

Sewage and effluent discharges from HKUST are governed by the Water Pollution Control Ordinance of Hong Kong. Sewage from HKUST is discharged to the Junk Bay municipal sewage treatment facility by a sewage pipe which uses a dedicated tunnel under the mountain between HKUST and Junk Bay. A license is required for this sewage discharge and under the terms of the license, the Environmental Protection Department (EPD) of Hong Kong has the statutory authority to sample the HKUST discharge for compliance monitoring. The management plan described here is designed to satisfy the requirements of all applicable EPD regulations.

All chemical wastes in Hong Kong are controlled by the Waste Disposal ( Chemical Waste) (General) Regulation. Most of the chemical wastes generated in Hong Kong are sent to the Chemical Waste Treatment Centre (CWTC) at Tsing Yi Island which is managed by a wastes treatment company under contract to the EPD. The three main treatment process systems at CWTC are oily water separation, physical/chemical treatment (neutralization, precipitation, chromium reduction, inorganic metallic waste treatment, evaporation, catalytic oxidation, stabilization), and incineration. Chemical wastes which are not accepted by the CWTC are normally co-disposed at landfills which are designated for hazardous wastes. Such waste requires a disposal permit from the EPD and must be collected for disposal through a licensed chemical waste collector.

B. Types of Waste Management Planning

Chemical Waste

Regulated Chemical Waste
Waste materials which are regulated as chemical waste are listed in the "Procedures for Disposal of Chemical Waste" Handbook. Disposal of these materials must follow procedures described in this chapter in order to comply with EPD regulations. For chemicals not on this list, prudent practice summarized in this chapter shall be employed for their disposal. Contact the Health, Safety and Environment Office (HSEO) if additional information is required.

There are three chemical waste disposal schemes at HKUST.

i.	Chemical wastes to be disposed to the standard containers which are provided by the CWTC . Most of the chemical wastes can be collected under this scheme. For details, please refer to the “Procedures for Disposal of Chemical Waste” in section V.A.
ii.	Lab-pack Scheme. For highly reactive and water reactive chemicals, as well as wastes that fail the compatibility test, disposal can be accomplished through the Lab-pack Scheme. Some expired and/or unwanted chemicals may also be disposed via this scheme. Details of this disposal scheme are written in the “Handling Lab-pack Wastes” in V.B.3 of the "Procedures for Disposal of Chemical Waste Handbook".
iii.	Hazardous solid wastes Some solid chemical wastes and non-hazardous materials which are contaminated with significant amount of hazardous chemicals should be disposed of by various methods according to their chemical nature and physical state. Please refer to the “Procedures for Disposal of Hazardous Solid Wastes” in the "Procedures for Disposal of Chemical Waste Handbook".

Materials approved for disposal into the municipal sewer system include:

Inorganic acids
Alkalis
Non-toxic inorganic salts in aqueous solution

Prior to disposal, these materials must be neutralized to within a pH range of 6 - 10.

For operations which generate large amount of acids or alkalis (e.g. monthly production rate >10L ) and which lack a neutralization facility, an alternative disposal solution is to request a spent acid or alkali standard container from HSEO. In these cases, follow the first disposal scheme for chemical wastes which is mentioned above in number 1.

II.

Biological Waste

Any material containing a class 2 or above microorganism needs to be sterilized prior to disposal. Autoclaved liquid waste can be discharged into the sewer. Autoclaved solid waste can be disposed as municipal waste at landfills. Autoclaved sharps shall be contained in non-penetrating containers prior to disposal as municipal waste at landfills. Autoclavable bags, sharps boxes, etc. are available from the CLS (Center of Laboratory Supplies).

Biological materials which are co-contaminated with toxic chemicals or radioactive isotopes should not be sterilized by steam since that will contaminate the autoclave. They need to be segregated from other biological waste material and be treated differently. In general, the material needs to be treated with a chemical disinfectant and then be handled as a chemical or radioactive waste. An inappropriate choice of disinfectant can be hazardous. For example, adding hypochlorite disinfectant to a material containing radioiodine can result in the release of the radioactive iodine. Contact HSEO for further information on proper treatment and disposal of co-contaminated waste.

Animal carcasses must be disposed according to relevant regulatory requirement established by the Environmental Protection Department. Animal carcasses must be wrapped in opaque plastic bags and send to the carcasses storage freezers in the Animal Care Centre immediately. Sharps such as scalpels, hypodermic needles, and awls must not be included in the pack otherwise they may cause injury to the waste handler during transportation. Also see Chapter 9.

III.

Radioactive Waste

Low levels of radioactive isotopes may be discharged into the sanitary sewer system. A single monthly discharge limit is established to cover all operations for the entire campus. The exact quantity varies as a function of the specific isotopes involved. In general, dischargeable quantities of 125 I, 3 H, 14 C, 32 P and 35 S are in the pico curie range. HSEO regularly collects radioactive wastes from all departments and dispose them after thorough evaluation. HSEO will keep track of the quantities of radioactive wastes collected in order to assure that the limit is not exceeded.

Materials with non-dischargeable levels of radioisotopes need to be segregated and stored until the radioactivity levels are acceptable for disposal. Some materials can be stored at the waste accumulation site on campus while others may need to be transported back to the Radiation Board for long term storage at designated locations. For details of Radioactive Waste Management, please refer to Chapter 10, Section N.

IV.

Sharps

Sharps such as hypodermic needles and scalpels shall be put in non-penetrable containers. The sealed container is then disposed of as municipal waste. Sharps with biological contamination shall be sterilized before disposal.

Broken glass shall be put in the broken glass cartons which are provided by CLS. Empty reagent bottles shall be cleaned prior to disposal. Call the CLS Chemical & Dangerous Goods section for collection of these items.

C. Responsibilities

I.	Users are responsible for: Segregating waste material in the laboratory according to the indicated waste-streams. Accurately completing forms related to hazardous waste management (e.g. chemical waste log-sheet, lab-pack waste forms). Storing and managing the waste safely within the lab or workshop before collection.
II.	Center of Laboratory Supplies is responsible for: Provision of general items (e.g. autoclavable bags, sharps boxes, broken glass containers, hazard warning labels, etc.) for hazardous waste management. Collection of broken glass and empty reagent bottles.
III.	HSEO is responsible for: Providing guidance on the overall management of hazardous waste. Evaluating the operation for regulatory compliance. Securing waste disposal permits & sewage discharge license. Arranging for waste disposal contractor pick-ups. Providing approved, standard chemical waste containers from CWTC. Transporting waste from the lab to the accumulation area. Managing the waste accumulation area. Preparing waste for pick-up and transportation to the disposal site.

D. Procedures for Disposal of Chemical Waste

The procedures for disposal of chemical waste are detailed in the Procedures for Disposal of Chemical Waste Handbook.