Richard McKinlay, principal consultant in the Waste and Resources Directorate at WRc, examines how England can treat more waste domestically by bridging the POPs capacity gap.
A recent project undertaken by WRc and Tolvik for the Office for Environmental Protection (OEP) has found there is a capacity gap for treating the volume of waste containing persistent organic pollutants (POPs) across the UK.
As POPs waste tonnages are predicted to grow, there is a shortfall in processing capability. WRc Waste and Resources Principal Consultant Richard McKinlay, principal author of the OEP report, explores how this gap can be bridged and POPs waste can be effectively handled domestically.
POPs can build up in the environment and are particularly harmful when not appropriately managed. They are present in many everyday products, such as upholstered seat cushions and carpets, polystyrene wall insulation and old electricals.
For the last 25 years, the Stockholm Convention has required signatories to reduce or eliminate POPs. While the UK government has committed to increasing POPs waste destruction as part of its Environmental Improvement Plan (EIP).
To support this ambition, the OEP commissioned a report to understand what this means in practice and whether it is feasible.
Assessing the current regulatory market, what market controls are in place and the demand for waste treatment and available capacity, it found that there is a gap between capacity and the projected volumes of waste in need of processing, a shortfall of about 400,000 tonnes per year.
This is partly due to growing POPs waste volumes. There is a time lag between classifying substances as a POP and removing them from production and use, when they can still be used and incorporated into products without breach of regulation.
It can be many years before these products are discarded, and greater waste quantities designated as POPs are expected as this process rolls out.
Handling this is going to be a challenge for the waste industry, but there are effective solutions available that can reduce the need to export to European processors or resort to long-term storage.
Effective segregation at source
Volumes of POPs waste can be reduced through effective identification and separation, focusing destruction on actual POPs waste.
This could be highly effective in the construction and demolition sector, where there are many potential sources of POPs waste in old buildings that, if placed in general skips, may require the whole lot to be classified as POPs waste.
Identifying and segregating this at source will not only make these materials easier to handle but also ensure that only POPs waste is destroyed, reducing demands on capacity.
Effective sorting at the treatment stage
Similarly, more effective sorting after collection can help reduce volumes of POPs waste. Manual sorting is an option, as well as commercial-scale technologies. Machine-based sorting methods are well developed for electronics recycling and could be deployed further.
New technologies need their effectiveness to be evaluated and validated to demonstrate high sorting efficiency. POPs removal efficiency is expected to be very high in the UK, and in my experience, technologies must be validated and the recovery of a POPs-free product justified through rigorous testing.
Thoroughly evaluating technologies, such as X-ray transmission and X-ray fluorescence, can show significant cost savings through improved efficiency, despite potentially higher initial capital costs.
Investment in domestic incineration capacity
Incineration is viewed as the most effective management method, and the UK has dozens of municipal waste incinerators.
However, only a few facilities can accept a wide range of POPs waste and may not reach the temperatures needed for their destruction. Investment in high-temperature incineration infrastructure domestically will be critical.
As with sorting, any new infrastructure needs to demonstrate its destruction efficiency. Technical guidance states that the POPs destruction efficiency should exceed 99.999%. We have evaluated several processes, overcoming a variety of practical and analytical challenges to provide positive evidence at this level.
Eliminate POPs and potential POPs from new products
Finally, we must restrict the manufacture and use of these substances once identified. In the EU, the REACH Regulation is used to identify and limit the use of substances that may be designated as POPs in the future. The UK has a similar system, but regulation and enforcement in other non-EU manufacturing centres may be less rigorous.
Taking a more thorough approach to domestic procurement could also have a big impact. The UK and EU have phased out substances such as chlorinated paraffins, and where exporting countries have different regulations or exemptions, testing can help satisfy retailers of a POPs-free product.
While the increases in waste volumes stated in the report are projections, even a small increase in POPs waste tonnage will challenge current capacity. Better sorting and segregation would minimise the quantities of waste classified as POP, and effective sampling and testing will help balance demand and capacity.
If these substances are removed from new products, effective segregation and sorting are implemented, and further treatment capacity is installed and validated, the UK has a greater chance of meeting its obligations under the Stockholm Convention.