City of Busselton – Construction Products
Context and purpose of the guideline and how it fits into the current regulatory framework
Through the development of this guidance the DER is seeking to encourage the use of waste-derived materials in circumstances where their use does not cause an unacceptable risk to the environment to encourage material re-use, divert waste from landfill and reduce the demand for raw materials and fossil fuels.
This guidance pertains specifically to construction products, among other items, sets out the ‘end of waste’ criteria that DER will apply, which include
a) That the production and/or characteristics of the waste-derived materials will meet defined and relevant specifications or standards as evidenced through appropriate quality
assurance/sampling and testing systems; and
b) That the waste-derived materials will be used to replace a raw material and that use will not result in unacceptable impact on the environment.
In particular, it relates to the production of road base and drainage rock. If recycled road base and drainage rock are produced in accordance with the specifications, procedures, testing and record keeping requirements, and for the authorised uses set out in the Material Guideline, DER will regard them as having ceased to be waste when exercising its regulatory powers.
The specification, procedures, testing and record keeping requirements are intended to be designed to ensure the end use of these products does not pose unacceptable risks to the environment or human health.
Specifications and procedures required Product specification
According to the proposed guidance, if recycled road base and recycled drainage rock are produced and used in accordance with the specifications, procedures, testing and record keeping
requirements, and authorised uses set out below, they will no longer be regarded as waste by DER.
Table 2 of the proposed guidance sets out the maximum chemical concentration and other attributes of recycled road base and recycled drainage rock (column 2, parts 1 through 5 of the table). This table include maximum limits for metals, organic compounds, physical parameter (pH), inorganic species (asbestos) and permitted other wastes (other than concrete, bricks, tiles, ceramics, asphalt, sand and recovered glass).
The source for the proposed concentration limits are as follows:
For metals, DEC WA (2012) Western Australian Guidelines for biosolids management, except for Chromium (III), which is taken from South Australia EPA (2013) Standard for production and use of Waste-Derived Fill.
For organic compounds, EPA (2013) Standard for production and use of Waste-Derived Fill,
intermediate criteria, except for Benzene, which is taken from South Australia EPA (2013) Standard for production and use of Waste-Derived Fill.
For pH, New South Wales EPA (2012) The excavated natural material exemption.
For Inorganic species (Asbestos), DEC WA (2012) Guidelines for managing asbestos at construction and demolition waste recycling facilities.
Biosolids management guidelines are concerned with the beneficial use of biosolids through land application on agricultural and forestry land, mine site rehabilitation and landcare programs. They are, therefore, restricted to biosolids produced from municipal wastewater plants treating
domestic and industrial wastes.
Limits imposed for the purpose of biosolids management are related to contaminant uptake, toxicity, bioaccumulation and mobilisation in the context of soil improvement applications.
This is a completely different use from road base and drainage rock applications, as the latter are not intended to be embedded in agricultural/forestry soil substrate improvement and direct contact with growing plants or trees.
In addition, recycled construction materials are fundamentally different from biosolids, in the sense that biosolids are supposed to have really minor quantities of mineral materials, including metals.
Moreover, given natural variability (of metal contents) of naturally occurring sand and rock materials, we believe it does not make much sense to regulate waste-derived materials over and above the restrictions imposed on naturally occurring materials for the same applications. Rather, waste-derived materials should pass the muster of contaminated soil standards for a variety of other land-disposal applications.
Also, the extent to which a given metal is problematic in terms of soil contamination, relates to the leaching properties of the chemicals present, and not the concentrations per se.
Standard AS 4439.3—1997 provides a method for the preparation of leachates from liquid and solid wastes, sediments, sludges and soils for assessing the potential of inorganic and semivolatile organic contamination of groundwater, in a variety of disposal-to-land scenarios.
Significantly, the New South Wales EPA Environmental Guidelines for the Assessment, Classification and Management of Non-liquid Wastes clearly endorses AS 4439 as the preferred procedure.
As such, we believe this would be the most appropriate standard both in terms of
procedure/method and levels of reference to be considered to test for metals, rather than the biosolids guidelines.
Operational control procedures
An excessive burden seems to be placed on acceptance procedures, as they require all loads of C&D waste for use in the production of recycled road base and/or recycled drainage to be spread over to allow a comprehensive visual and odour inspection of all sides of the material. This means, according to the guidance, to spread the material to a depth of less than 30 cm and to turn over the material with the use of an excavator or similar vehicle. This would require full time presence of the required plant and competent staff, which might not be viable for regional local councils operating C&D recycling premises.
Waste processing controls
The guidance states that blending of materials is permitted providing each of the streams being blended meets the product specification. As indicated, this means that sampling and testing of the different streams of materials to be blended must take place prior to the blending activity being undertaken.
This is unclear as there is no definition of what the term ‘streams’ applies to. If a load of C&D material would be considered one stream, sampling and testing requirements would seem rather excessive.
Moreover, given natural variability of input materials, applying product specification criteria to incoming product streams as a process control procedure seems excessive and unnecessary,
provided that the final product passes the relevant criteria, which should be necessary and sufficient to prevent unacceptable risks to the environment or human health
It is our view that if the DER considers that all incoming materials should comply with the finished product criteria, then DER should impose such a requirement to waste producers rather than to processers, and require waste producers (construction and demolition contractors and other organisations) to sample and test the materials and to dispose of them as waste, as necessary.
Regards,
Vitor Martins Waste Coordinator
p: (08) 9781 0425 m: 0407 365 497 Vitor.Martins@busselton.wa.gov.au
City of Busselton
Locked Bag 1 - 2 Southern Drive, Busselton WA 6280 p: (08) 9781 0444 f: (08) 9752 4958
www.busselton.wa.gov.au
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