A. KEY TIMELINE: 

Mar 2025.  The Environment Agency updated its Flood Map for Planning, which re-classified part of the site into Flood Risk Zone 3. 

Jun 2025.  Highways reported "no objections" to Acorn's traffic management plan - 

Maximum 140 two-way movements per day (70 in, 70 out) for up to 28 days per annum.  Modified to 24 days in May 2026 plan
Maximum 80 two-way movements per day (40 in, 40 out) for up to 337 days per annum.  Modified to 341 days in May 2026 plan

Dec 2025.  The Environment Agency objected to the development because it would handle hazardous materials in Flood Risk Zone 3.

May 2026.  Acorn submitted 40 new documents. Most significant of these documents was a revised layout, moving everything 40 metres southeast (out of flood zone 3) to overcome the Environment Agency objection of December 2025.

May 2026. Buckinghamshire Council re-opened the application for consultation, with a deadline of 19th June 2026. 

August 2026 (TBC). The Case Officer will then compile his recommendation to the Strategic Sites Committee, which will make a decision. The meeting is currently very provisionally pencilled in for the August meeting scheduled for Thursday 27 August. 

B. CORE POINTS OF COMMUNITY OBJECTION

• Location

This proposal is for an industrial-scale facility located in an Area of Attractive Landscape. The site is located on a minor road and can only be accessed through rural villages.  60% of feedstock will be sourced from farms over 5KM from the proposed site, delivered by HGV through these villages. 

Proposed mitigation by Acorn for visual impact (ie planting of trees and hedgerows) will take longer to establish and create an effective buffer/screen than the expected life of the plant and therefore will be totally ineffective.

In addition, Acorn have not made any undertaking in their application to return the land to arable use when the plant is decommissioned (accounting for 4.63ha of impermeable hardstanding). 

The proposed anaerobic digester is situated 1.23km north of Bailey's private airfield (51°46'49.0"N 1°01'11.8"W), giving rise to safety concerns, which need to be addressed explicitly within the consultee responses.

• Highways

Road capacity in Long Crendon has already been cited by Highways as a major constraint in outline housing development planning applications in March 2026. The additional HGV traffic that would arise from the proposed anaerobic digester, clearly requires the Highways Officer to comment in detail on local capacity. In addition, risk to safety and operation of the highway arising from opposing HGV's on single-track rural roads has been unacceptably dismissed to date by the Highways Officer and must be addressed in detail in the next consultation.

In the latest design documents from Acorn (May 2026), the capacity of the lagoon has been reduced substantially (by 54.6%). This will undoubtedly lead to increased export trips (as capacity of the plant has not been similarly decreased), but Acorn have not included any adjustment in their latest documentation. This must be therefore clarified by Acorn and considered in a revised statement from Highways.

In addition, in March 2026, the Reg 18 consultation for development of the Local Plan for Buckinghamshire to 2045 allocated 418 new dwellings to Long Crendon.  The additional weight of traffic arising from this plan needs to be considered in the Highways report as it coincides with the lifetime of the proposed anaerobic digester plant. 

• Environment Statement

In February 2026, the government published updated statutory guidance on the installation and risk management of anaerobic digesters (SR2021 No.6).  The Environment Agency's (EA) response to Acorn's prior proposal pre-dates this updated guidance, and it is therefore essential that the EA's advice to the Local Planning Authority (LPA) fully evaluates Acorn's updated proposal against these regulations.  

With the reduced size of the lagoon, in addition to highway implications (in ii. above) it is essential that the LPA asks Acorn to clarify and comment on how excess digestate would be resolved in order to avoid the risk of overflow into the sensitive water course within adjacent flood zone 3, as no explanation or comment has been provided in this regard.

Acorn’s air quality assessments are totally insufficient, including no consideration of human receptors in Long Crendon, the nearest area of highest residential density. Acorn have not demonstrated in any of the submissions the requirements set out in section 3 of the updated statutory guidance (SR2021 No 6). 

Section 2.2.4 (b) of the updated statutory guidance (SR2021 No 6) also provides that the site shall not be within 250 metres of the nearest sensitive receptor where any treatment by composting of digestate fibre is in the open.  The site boundary is less than 250M from Hornage Farm, a Grade 2 listed building.  Acorn has not considered the impact of odour, or noise and vibration on Hornage Farm.

• Environmental Statement (ES) Chapter 5 , Landscape and Visual Impact Statement

Buckinghamshire Council's landscape officer (April 2025), the Planning Officer (March 2026), and the Applicant (May 2026) have consistently failed to acknowledge and respond to HADO's images (HADO = Hornage Anaerobic Digester Objection), and HADO’s comments on the use of incorrect methodology in their ES chapter 5.  These should be explicitly addressed in the latest consultations.

The proposed anaerobic digester consists of a substantial modern, large scale industrial development in a rural landscape where industrial land uses are identified by Buckinghamshire Council as detractors.   It would have a significant effect on the surrounding landscape and an adverse impact on its character and distinctiveness. It would be inconsistent with the objectives of the relevant landscape planning policies and would not meet their criteria for approval.

The landscape character assessment methodology does not follow Landscape Institute Guidance and underestimates the impact of the proposed facility on landscape character and views.  In addition to mitigation through boundary planting not being effective (see i. Location), the Landscape & Visual Impact Assessment (LVIA) fails to consider the dominant scale of lightning arresters. 

• Hornage Cops (Ancient Replanted Woodland)

Natural England raised no objections to the proposed anaerobic digester.  However, Air Quality Assessments, on which their opinion was based, pre-date Acorn's decision to source 10% of feedstock via a farm track that runs immediately adjacent to Hornage Copse (Ancient Replanted Woodland). In light of this, Natural England need to reconsider their opinion, including the significant volume of traffic – and associated air pollution - passing Hornage Copse.   

In addition, none of the Air Quality Assessments provided by Acorn or conducted on behalf of the LPA recognise the impact of an existing waste treatment facility about 2.9 KM southwest of Hornage Copse on background emissions at Kirtland Farm.  The cumulative impact of emissions from this facility and the proposed anaerobic digester should be considered in the applicant's Air Quality report and reviewed by Natural England and the Environment Agency before any planning decisions are made.

May 2026