The Environment Agency (EA) has released an updated end-of-waste quality protocol for anaerobic digestate (ADQP), which is a nutrient-rich co-product of anaerobic digestion that can be used as an organic ‘biofertiliser’.

Launched by the EA with support from WRAP and industry representatives, the new document updates the ADQP (first published in 2010) to ‘provide greater clarity and additional clarification of acceptable input materials and their associated codes’.

The revised QP is applicable in England, Wales, and Northern Ireland, with a transition period of two months for existing QP producers and users (until 10 April 2014).

QP details

The ADQP sets out criteria for the production of quality digestate from anaerobic digestion of source-segregated biodegradable waste (biowaste) and verifies when outputs from AD are considered to have been ‘full recovered’, and thus cease to be waste.

Although producers, processors and users are not obliged to comply with the QP, if they do not, they must adhere to the relevant waste management controls for the storage, handling, transportation, and application of digestate.

Updates to the ADQP include:

• the removal of the requirement for land managers using digestate to maintain records for the specific purposes of the QP;
• a clarification of acceptable inputs and associated codes, including additional codes to describe waste that is subject to certain forms of pre-treatment at facilities between the site of waste production and the AD facility;
• the removal of tanning liquor and sludges from permitted inputs; and
• the inclusion of a good practice section covering storage, handling and use of anaerobic digestate.

In order for digestate to cease to be waste, the QP outlines that it must:

• be produced using only those source-segregated input materials listed in the QP;
• meet the requirements of an approved standard (described in the QP);
• bedestined for ‘appropriate use’ in one of the designated market sectors;
• require no further processing including maturation or re-screening for use in the designated market sector for which it is destined; and
• meet any additional customer specifications, as agreed between the supplier and the customer.

It is hoped the ADQP will help to ‘clarify the point at which waste management controls are no longer required, provide users with confidence that the quality digestate they purchase conforms to an approved standard; and protect human health and the environment (including soil) by describing acceptable good practice for the use of quality digestate in agriculture, forestry, soil/field-grown horticulture and in land restoration’.

QP will ‘build confidence in the market for biofertiliser’

The quality protocol will be hosted on the Biofertiliser Certification Scheme website, which is operated by Renewable Energy Assurance Ltd (REAL), a subsidiary of the Renewable Energy Association (REA).

It comes ahead of the release of the British Standards Institution’s (BSI) updated PAS 110 certification for digestate, which specifies the minimum quality requirements for whole digestate, separated liquor and separated fibre.

REAL Certification Manager Ciaran Burns said: “Along with the forthcoming update to the PAS 110, these updates will provide clarity on the regulations for digestate producers and further build confidence in the market for biofertiliser.

“This update to the ADQP makes several improvements, reducing the administration burden for producers and rationalising the list of appropriate feedstocks. This will increase the value of digestate products and boost the overall economics of anaerobic digestion as a source of renewable biogas.”

Matt Hindle, Policy Manager at the Anaerobic Digestion and Biogas Association (ADBA) added: “The revised ADQP is a useful step forward, but the key now is for the environmental regulators to quickly confirm that the new version of PAS 110 meets their end-of-waste standards.

“As the regulators have been involved throughout the process, we hope this will be a simple process once BSI publish the document, and we hope to see a new PAS 110 alongside the QP by early April.”

The REA also welcomed the publication of the updated QP, with REA Head of Biogas David Collins saying: “It is great to get the updated ADQP hot on the heels of the new Biomethane QP. The good news comes at a challenging time for the industry, as we work with DECC and partners to resolve issues with the Feed-in Tariff. Building market confidence in AD outputs, including digestate, can have a real positive impact on the economics of biogas, so this regulatory boost is timely indeed.”

Read the updated QP for anaerobic digestate.