General solid waste (as the name would suggest) can be composed of a variety of different contaminants, and it needs to be accurately classified before remediation begins.
Required classification of general solid waste
This is the first step to appropriately dispose and manage potential environmental and health risks, associated with general solid waste material. You are in fact required by law (Protection of the Environment Operations Act of 1997) to classify waste correctly before disposal. There are costly penalties for failing to complete this important step.
Steps to classify general solid waste
General Solid Waste (non putrescible) and General Solid Waste (putrescible) are waste categories classified under the NSW EPA Waste Classification Guidelines, and there are six steps in identifying the waste as detailed below:
- Determine if the waste is a Special Waste (contains asbestos).
- If it is not a Special Waste, determine if it is a Liquid Waste.
- If it is not a Special or Liquid Waste, determine if it is a waste pre-classified by the NSW EPA.
- If it is not a Special, Liquid or pre-classified waste, determine if it has characteristics that can classify it as a Hazardous Waste.
- If the waste does not display characteristics that classify it as a Hazardous Waste then conduct chemical analysis to determine if it is a Hazardous, Restricted Solid or General Solid (non putrescible and putrescible) Waste.
- If the waste is determined to be a General Solid Waste, assess it to determine if it is non-putrescible or putrescible in nature.
Testing general solid waste
The chemical contaminants in general waste have two measurable properties that can be used to aid classification.
1. Specific contaminant concentration (SCC) (mg/kg)
The SCC test acts as an initial screening test for the classification of a waste. Based on SCC alone, the test value for each contaminant must be less than, or equal to, the contaminant threshold (CT) specified for that contaminant in the NSW EPA Waste Classification Guidelines.
2. Leachable concentration of contaminant
The next test we would complete would use the SCC as above, and also the Toxicity Characteristics Leaching Procedure (TCLP) (mg/L). The SCC and TCLP test values, for each chemical contaminant, must be compared to the threshold values set out in the NSW EPA Waste Classification Guidelines. If either the SCC or TCLP values exceed threshold guidelines for General Solid Waste, the waste must be classified as Restricted Solid Waste. If the values exceed those for Restricted Solid Waste, it must be classified as Hazardous Waste. Detailed interpretative guidance regarding the use of both SCC and TCLP values should be attained from a specialist in waste management, such as AES.
Pre-classified general solid wastes
NSW EPA has issued a list of pre-classified general solid wastes, whether putrescible or non-putrescible, which every waste generator or agent acting on their behalf must be familiar with.
General Solid Waste (non-putrescible)
Common non-putrescible waste items include glass, plastic, rubber, ceramics, bricks, cement or metal materials, soils, timber, garden trimmings, agricultural, forestry and crop materials, as well as natural fibrous organic and vegetative materials. Indeed there are many itemised wastes in this pre-classified list however as a guide, non-putrescible wastes typically:
- do not readily decay under standard conditions
- do not emit offensive odours
- do not attract vermin or other vectors such as flies, birds and rodents
General Solid Waste (Putrescible)
Solid Wastes are putrescible if they are any of the following:
- household wastes that contain putrescible organics
- waste from litter bins collected by or on behalf of local councils
- manure and night soil
- disposable nappies, incontinence pads or sanitary napkins
- food or animal waste
- grit or screenings from sewage treatment systems that have been dewatered so that the grit or screenings do not contain free liquids
- any mixture of the wastes mentioned above
Be aware however that from time to time, new materials may be classified as General Solid Waste (putrescible) by the EPA. These are published in the NSW Government Gazette, and on EPA’s website at www.environment.nsw.gov.au/waste/wastetypes.htm.
To avoid any issues you need to stay up to date.