A draft quality standard for digestate produced from bio-waste through anaerobic digestion could be available by the end of this year and is set to see the digestate classed as a product, rather than a waste.

Sharon Russell-Verma, implementation manager for the Waste & Resources Action Programme, revealed at the recent Recycling and Waste Forum that a PAS110 standard is in development and is "well on the way" to a first-draft being completed. She said: "The details for quality digestate and how it should be produced are drafted and we expect a resolution review in April or May."

Ms Russell-Verma also spoke about the development of the AD Quality Protocol in conjunction with the PAS 110 standard.

She said: "We have been collaborating with industry and the Composting Association to help gather the quality protocol together." That is also in its draft stages and Ms Russell-Verma confirmed that financial assessment and exposure pathway assessments have both been completed."

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She hoped that the standardisation would help the image of digestate produced in AD facilities, Ms Russell-Verma explained: "The fact digestate is seen as a waste is a barrier, seeing it as a product will bring more certainty to digestate." Currently digestate is classed as a waste but the AD quality protocol and PAS 110 standard will enable it to be supplied and used as a product in markets recognised by the AD QP.

The quality protocol and PAS 110 are both designed to open up the markets for AD outputs and to give more confidence in it as a product, she explained and Ms Russell-Verma hopes that it will provide more end-users for the digestate.

The protocol is currently in consultation and WRAP is seeking feedback from the bio-waste management industry to help shape the final document. Ms Russell-Verma requested that anyone who is interested in contributing to the consultation should visit Protocol Consultation and make their views known. The consultation on the AD QP is open until June 26 and the quality protocol and PAS 110 standard is expected to be available in autumn 2008.

Responses

Responses to the protocol consultation are being submitted to the technical advisory group to Defra, the Environment Agency and the Waste & Resources Action Programme. Responses to the draft PAS 110 have been submitted to BSI. The response from the Local Authority Recycling Advisory Committee (LARAC) makes several points.

It says that the document defines source segregated incorrectly, because it infers that source segregated material cannot then be blended/combined with other wastes.

Larac points out that subsequent processing does not alter the source segregated status. It notes that garden waste might be source segregated and separately collected but subsequently blended with proportions of food waste to improve processability.

Protocols

The work on AD comes under the Waste Protocols Project which is a joint Environment Agency and WRAP initiative in collaboration with industry, funded by Defra and the BREW programme. WRAP says that the project aims to achieve one of the following outcomes:

• produce a Quality Protocol (QP) which clearly sets out the steps that must be taken for the waste to become a non-waste product or material that can be either reused by business or industry, or supplied into other markets, enabling recovered products to be used without the need for waste regulation controls;
• produce a regulatory position statement, which clearly informs the business community of what regulatory obligations they must comply with to use the processed waste material.