When it comes to property development, rising soil disposal costs puts a spotlight on soil waste strategies, particularly when dealing with contaminated soil. Depending on the risk profile of contaminated soil being removed from a site, disposal costs can come in at anywhere between $200 and $1,000 per tonne. Even disposal costs for clean soil which can range between $20 and $60 can still have a significant financial impact. If you consider the excavation required for a basement car park, excess soil can easily result in a few thousand tonnes and provides a good example of the value to be gained from smart waste management strategies.
Under current New South Wales environmental protection legislation, illegally accepting and disposing of contaminated soils can lead to heavy fines. There is also legislation in place that aims to encourage ecologically sustainable development and recycling to help conserve landfill.
Waste Avoidance Framework
The principle aim of the Waste Avoidance Resource Recovery Act of 2001 (WARR) is to reduce the impact of waste on the environment and the high cost of disposal fees helps to reinforce this goal. Under the WARR the following hierarchy is applied in the aim to reduce waste:
Step 1: Waste avoidance
Step 2: Resource recovery
Step 3: Disposal
Step 1: Waste Avoidance
When it comes to soil waste, excavation strategies can help reduce disposal requirements. For example avoiding a cut and fill approach or developing a balanced cut and fill plan can help to minimise soil waste.
Step 2: Resource Recovery
Resource recovery requirements cover onsite reuse, offsite reuse, and soil recycling.
Onsite reuse is the preferred option because it doesn’t incur any transport costs or disposal fees. Strategies for onsite reuse include:
- Screening out construction waste and other debris from soil to enable it to be used as fill;
- Undertaking a contamination assessment of fill to determine whether there’s an opportunity to reuse it without negatively affecting the environment or human health (ie. a site specific risk assessment);
- Undertaking remediation of contaminated soils for reuse as fill;
- Utilising an onsite containment cell to manage contaminated soils ( subject to some restrictions and documentation requirements).
Uncontaminated natural soil that doesn’t contain acid sulphate soils, natural asbestos, or sulfidic ores (legally defined as Virgin Excavated Natural Material or VENM) can be readily used offsite.
Soil waste that has been disturbed or contaminated from past or previous land uses will not meet a VENM classification. However, the regulations provide for some exemptions to allow ‘non-virgin’ but low risk soil to be safely reused. Such soil is classified as ENM (Excavated Natural Material). The ENM exemption requires a visual, chemical and physical assessment to ensure soil meets the relevant ENM criteria.
In some instances where a resource recovery exemption isn’t satisfied, it may still be possible to seek a site-specific resource recovery exemption. Again, contamination assessment is required.
Soil recycling is also an option when soil hasn’t qualified for offsite reuse under specific resource recovery exemptions. It is important to note that, there are no uniform standards for recyclers, however, under the POEO Act, every soil recycler in NSW will have an individual license which states the criteria soil waste must meet in order to be accepted.
Step 3: Waste Disposal
If soil wastes cannot be reused onsite or offsite and unable to be accepted by a soil recycler, then it must be sent to a landfill and consequently incur disposal fees (which is why soil waste avoidance is so important). Any soil waste being disposed not only needs to go to a licensed facility but also needs to be classified under the NSW EPA’s Waste Classification Guidelines. Even though correct disposal can be expensive, any landowners who accept contaminated fill or illegally dispose of such, can receive big fines.
Three categories of waste are defined by the EPA’s Waste Classification Guidelines:
- GSW (General Solid Waste – non-putrescible);
- HW (Hazardous Waste); and
- RSW (Restricted Solid Waste).
If asbestos is found within soil, this must be classified as Special Waste and needs to be disposed of at a specially licensed landfill facility.
Soil waste cannot be disposed legally without a waste classification which is performed by a qualified consultant. As the process is complicated and highly regulated, there is much to gain from receiving some expert advice.
Geo-Logix’s land contamination specialists can provide you with waste disposal strategies and waste classification services. For more information, please browse our website or call Ben Pearce at 02 9979 17221.