Although large industries may be responsible for the proper management of wastes consisting of, containing or contaminated with POPs that they generate or own, many smaller entities also possess such wastes. The wastes consisting of, containing or contaminated with POPs possessed by small entities may include household- or commercial-sized pesticide containers, PCB fluorescent light ballasts, small containers of pentachlorophenol-based wood preservatives with PCDD and PCDF contamination, small amounts of “pure” POPs in laboratories and research facilities, and pesticide coated seeds used in agricultural and research settings. To deal with this scattered assortment of hazardous wastes, many governments have established depots where small quantities of these wastes can be deposited by the owner at no charge or for a nominal fee. These depots may be permanent or temporary in nature, or may be located at existing commercial hazardous-waste transfer stations. Waste collection depots and transfer stations may be set up on a regional basis by groups of countries or may be provided by a developed country to a developing country.
Care should be taken in establishing and operating waste collection programmes, depots and transfer stations:
(a) To advertise the programme, depot locations and collection time periods to all potential holders of wastes consisting of, containing or contaminated with POPs;
(b) To allow enough time of operation of collection programmes for the complete collection of all potential wastes consisting of, containing or contaminated with POPs;28
(c) To include, to the extent practical, all wastes consisting of, containing or contaminated with POPs in the programme;
(d) To make acceptable containers and safe-transport materials available to waste owners for those waste materials that may need to be repackaged or made safe for transport;
(e) To establish simple, low-cost mechanisms for collection;
(f) To ensure the safety both of those delivering waste to depots and workers at the depots;
(g) To ensure that the operators of depots are using an accepted method of disposal;
(h) To ensure that the programme and facilities meet all applicable legislative requirements;
(i) To ensure separation of wastes consisting of, containing or contaminated with POPs from other waste streams.
Wastes consisting of, containing or contaminated with POPs should be properly packaged for ease of transport and as a safety measure to reduce the risk of leaks and spills. Packaging of hazardous wastes falls into two categories: packaging for transport and packaging for storage.
Packaging for transport is often controlled by national dangerous goods transportation legislation. For packaging specifications for transport, the reader should consult reference material published by IATA, IMO, UNECE and national governments.
Some general precepts for packaging of wastes consisting of, containing or contaminated with POPs for storage are as follows:
(a) Packaging that is acceptable for transport is, in most cases, suitable for storage;
(b) Such wastes in their original product containers are generally safe for storage if the packaging is in good condition;
(c) Such wastes should never be stored in product containers that were not intended to contain such wastes or that have labels on them that incorrectly identify the contents;
(d) Containers that are deteriorating or are deemed to be unsafe should be emptied or placed inside a sound outer package (overpack). When unsafe containers are emptied, the contents should be placed in appropriate new or refurbished containers. All new or refurbished containers should be clearly labelled as to their contents;
(e) Smaller containers can be packaged together in bulk by placing them in appropriate or approved larger containers containing absorbent material;
(f) Out-of-service equipment containing POPs may or may not constitute suitable packaging for storage. The determination of safety should be made on a case-by-case basis.
Labelling of products and articles consisting of, containing or contaminated with POPs is critical for the success of inventories and is a basic safety feature of any waste management system. Each waste container should be labelled to identify the container (e.g., ID number), the POPs present and the hazard level.
Wastes consisting of, containing or contaminated with POPs should be transported in an environmentally sound manner to avoid accidental spills and to track their transport and ultimate destination appropriately. Before transport, contingency plans should be prepared in order to minimize environmental impacts associated with spills, fires and other emergencies that could occur during transport. During transportation, such wastes should be identified, packaged and transported in accordance with the “United Nations Recommendations on the Transport of Dangerous Goods: Model Regulations (Orange Book)”. Persons transporting such wastes should be qualified and certified as carriers of hazardous materials and wastes.
Transportation of dangerous goods and wastes is regulated in most countries and the transboundary movement of wastes is controlled, in particular by the Basel Convention.
Companies transporting wastes within their own countries should be certified as carriers of hazardous materials and wastes, and their personnel should be qualified.
Guidance on the safe transportation of hazardous materials can be obtained from IATA, IMO, UNECE and ICAO.
Wastes consisting of, containing or contaminated with POPs should be stored safely, preferably in dedicated areas away from other materials and wastes. Storage areas should be designed to prevent the release of POPs to the environment by any route. Storage rooms, areas or buildings should be designed by professionals with expertise in the fields of structural design, waste management and occupational health and safety or can be purchased in prefabricated form from reputable suppliers.
Some basic principles of safe storage of wastes consisting of, containing or contaminated with POPs are as follows:
(a) Storage sites inside multi-purpose buildings should be in a locked dedicated room or partition that is not in an area of high use;
(b) Outdoor dedicated storage buildings or containers31 should be stored inside a lockable fenced enclosure;
(c) Separate storage areas, rooms or buildings should be used for each type of POPs waste, unless specific approval has been given for joint storage;
(d) Such wastes should not be stored at or near sensitive sites such as hospitals or other medical care facilities, schools, residences, food processing facilities, animal feed storage or processing facilities, agricultural operations, or facilities located near or within environmentally sensitive sites;
(e) Storage rooms, buildings and containers should be located and maintained in conditions that will minimize volatilization, including cool temperatures, reflective roofs and sidings, a shaded location, etc. When possible, particularly in warmer climates, storage rooms and buildings should be maintained under negative pressure with exhaust gases vented through carbon filters, bearing in mind the following conditions:
(i) Ventilating a site with carbon filtration of exhaust gases may be appropriate when exposure to vapours for those who work at the site and those living and working in the vicinity of the site is a concern;
(ii) Sealing and venting a site so that only well-filtered exhaust gases are released to outside air may be appropriate when environmental concerns are paramount;
(f) Dedicated buildings or containers should be in good condition and made of hard plastic or metal, not wood, fibreboard, drywall, plaster or insulation;
(g) The roofs of dedicated buildings or containers and the surrounding land should be sloped to provide drainage away from the site;
(h) Dedicated buildings or containers should be set on asphalt, concrete or durable (e.g., 6 mm) plastic sheeting;
(i) The floors of storage sites inside buildings should be concrete or durable (e.g., 6 mm plastic sheeting). Concrete should be coated with a durable epoxy polymer;
(j) Storage sites should have fire alarm systems;
(k) Storage sites inside buildings should have (preferably non-water) fire suppression systems. If the fire suppressant is water, then the floor of the storage room should be curbed and the floor drainage system should not lead to the sewer or storm sewer or directly to surface water but should have its own collection system, such as a sump;
(l) Liquid wastes should be placed in containment trays or a curbed, leak-proof area. The liquid containment volume should be at least 125 per cent of the liquid waste volume, taking into account the space taken up by stored items in the containment area;
(m) Contaminated solids should be stored in sealed containers such as barrels or pails, steel waste containers (lugger boxes) or in specially constructed trays or containers. Large volumes of material may be stored in bulk in dedicated shipping containers, buildings or vaults so long as they meet the safety and security requirements as described herein;
(n) A complete inventory of such wastes in the storage site should be created and kept up to date as waste is added or disposed of;
(o) The outside of the storage site should be labelled as a waste storage site;
(p) The site should be subjected to routine inspection for leaks, degradation of container materials, vandalism, integrity of fire alarms and fire suppression systems and general status of the site.
G. Environmentally sound disposal
This section presents some of the pre-treatment operations that may be required for the proper and safe operation of the disposal technologies described in the following subsections 2 and 3. There are also other pre-treatment operations which may be applied. Pre-treatment operations prior to disposal according to subsections 2 and 3 should be performed only if the POPs that are isolated from the waste during pre-treatment are subsequently disposed of in accordance with subsection 2. Where only part of a product or waste, such as waste equipment, contains or is contaminated with POPs, it should be separated and then disposed of as specified in subsections 1–4, as appropriate.
(a) Adsorption and absorption
“Sorption” is the general term for both absorption and adsorption processes. Sorption is a pre treatment method that uses solids for removing substances from liquids or gases. Adsorption involves the separation of a substance (liquid, oil, gas) from one phase and its accumulation at the surface of another (activated carbon, zeolite, silica, etc.). Absorption is the process whereby a material transferred from one phase to another interpenetrates the second phase (e.g., contaminant transferred from liquid phase onto activated carbon).
Adsorption and absorption processes can be used to concentrate contaminants and separate them from aqueous wastes and from gas streams. The concentrate and the adsorbent or absorbent may require treatment prior to disposal.
Dewatering is a pre-treatment process that partially removes water from the wastes to be treated. Dewatering can be employed for disposal technologies that are not suitable for aqueous wastes. For example, water will react explosively with molten salts or sodium. Depending on the nature of the contaminant, the resulting vapours may require condensation or scrubbing, and further treatment.
(c) Mechanical separation
Mechanical separation can be used to remove larger-sized debris from the waste stream or for technologies that may not be suitable for both soils and solid wastes.
Mixing of materials prior to waste treatment may be appropriate in order to optimize treatment efficiencies. However, mixing of wastes with POP contents above a defined low POP content with other materials solely for the purpose of generating a mixture with a POP content below the defined low POP content is not environmentally sound.
(e) Oil-water separation
Some treatment technologies are not suitable for aqueous wastes; others are not suitable for oily wastes. Oil-water separation can be employed in these situations to separate the oily phase from the water. Both the water and the oily phase may be contaminated after the separation and both may require treatment.
(f) pH adjustment
Some treatment technologies are most effective over a defined pH range and in these situations alkali, acid or CO2 are often used to control pH levels. Some technologies may also require pH adjustment as a post-treatment step.
(g) Size reduction
Some technologies are able to process wastes only within a certain size limit. For example, some may handle POP-contaminated solid wastes only if they are less than 200 mm in diameter. Size reduction can be used in these situations to reduce the waste components to a defined diameter. Other disposal technologies require slurries to be prepared prior to injection into the main reactor. It should be noted that facilities may become contaminated when reducing the size of wastes consisting of, containing or contaminated with POPs. Precautions should therefore be taken to prevent subsequent contamination of POP-free waste streams.
(h) Solvent washing
Solvent washing can be used to remove POPs from electrical equipment such as capacitors and transformers. This technology has also been used for the treatment of contaminated soil and sorption materials used in adsorption or absorption pre-treatment.
(i) Thermal desorption
Low-temperature thermal desorption (LTTD), also known as low-temperature thermal volatilization, thermal stripping and soil roasting, is an ex-situ remedial technology that uses heat physically to separate volatile and semi-volatile compounds and elements (most commonly petroleum hydrocarbons) from contaminated media (most commonly excavated soils). Such processes have been used for the decontamination of the non-porous surfaces of electrical equipment such as transformer carcasses that formerly contained PCB-containing dielectric fluids. Thermal desorption of wastes containing or contaminated with POPs may result in the formation of unintentional POPs which may require additional treatment.