The 1km Zone: Three Definitions, No Map, No Measurement Point

Update, April 2026 — A Fourth Definition

Since this post was published, Wyre Borough Council has verbally stated that the 1km zone is measured from the main stack at the Hillhouse estate — not from the estate boundary, the Technology Enterprise Zone, or the AGC Chemicals Europe facility as described in earlier written communications. This verbal statement has not, to our knowledge, been confirmed in writing or accompanied by a published map.

This adds a fourth definition to the three already documented below, and it raises further questions rather than resolving them:

• A 1km radius measured from the main stack would place significant portions of the advisory zone inside the Hillhouse industrial estate itself, rather than in surrounding residential areas. How does this affect residents living immediately outside the perimeter fence?
• A stack-centric measurement implies the zone is modelled on atmospheric deposition from a single point source. No dispersion modelling has been published that would show how wind direction, prevailing weather, or stack height have been factored in.
• Independent scientific research has detected EEA-NH4 — the fluorochemical currently being discharged from the estate — in air samples at Hazelrigg, approximately 20km away (Dalmijn et al., 2025). A 1km stack-centric zone has not been explained against this evidence of airborne transport at much greater distances.
• The original Food Standards Agency and Wyre Council communications describe the zone as “within 1km of the Hillhouse estate boundary” (and variants). Residents reading those documents would reasonably measure from the estate perimeter, not from an interior point. If the measurement reference has changed, this has not been communicated in writing.

The map published on The Numbers page shows a 1km buffer drawn from the Hillhouse estate boundary perimeter — this is Hillhouse Watch’s best-effort interpretation of the published written wording, not the official FSA/Wyre methodology as now verbally described. We do not have a published official map against which to verify any interpretation.

The questions previously put to Wyre Council and the Environment Agency now include: please publish, in writing and with a map, the measurement point, methodology, and scientific basis for the 1km advisory zone.

What We Know About the 1km Zone

On 2 February 2026, the Food Standards Agency and Wyre Council issued an advisory: residents within 1km of the Hillhouse estate boundary should not eat eggs from locally kept poultry. Residents within 1km were also advised to wash and peel garden produce. The FSA’s most recent update (5 March 2026) added: consider using raised beds with fresh soil.

This 1km zone is the spatial basis for official food safety advice currently affecting an unknown number of Thornton-Cleveleys residents. It determines who receives formal food safety guidance and who does not.

Three Inconsistent Descriptions

Across Wyre Council’s official documents and communications, the 1km zone has been described in at least three distinct formulations. The specific documents containing each formulation are being compiled and will be cited when confirmed. The three variants observed are:

1. “Within 1km of the Hillhouse estate boundary” — one formulation used in official communications
2. “Within 1km of the Hillhouse Technology Enterprise Zone” — a formulation appearing in other council documents
3. “Within 1km of the AGC Chemicals Europe facility” — a further variant in some communications

These are not equivalent. The Hillhouse estate boundary, the Technology Enterprise Zone boundary, and the AGC Chemicals Europe facility boundary are not the same perimeter. The measurement produces a different geographic footprint depending on which boundary is used as the starting point. [The specific documents containing each formulation will be cited here when confirmed — if you can identify which document uses which wording, please get in touch via the contact page.]

No map of the advisory zone has been published. No specific measurement methodology — such as: “measured from the nearest point of the [defined] boundary at [defined map reference]” — has been provided in publicly available documents.

What the FOI Response Said

An FOI request submitted to Wyre Council included a direct question about how the 1km zone was defined and measured (Question 5). Wyre Council’s response redirected the question to the Environment Agency.

This means the local authority implementing the advisory zone was, when asked formally, unable or unwilling to explain the basis on which that zone was drawn. The council that is asking residents to make food safety decisions based on their address within or outside this zone has not, in response to a direct FOI question, explained how the zone boundary was determined.

What This Means in Practice

Residents are making practical decisions — whether to keep poultry, whether to grow produce, whether to eat garden vegetables — based on their proximity to a boundary that:

• Has been described in three inconsistent ways across official documents
• Has not been defined with a specific reference point or methodology
• Has no published map
• Could not be explained by the implementing authority when asked directly

A resident asking “am I within 1km?” cannot currently verify whether they are, because the zone has not been defined precisely enough to answer that question against a specific address.

What Independent Testing Suggests About the Zone’s Scope

Phase 2 soil testing found PFAS in 287 of 291 samples (98.6%) — this programme covered only council-owned land, not residential properties. The first residential property tested under Phase 3 (WSP code SP510) had PFOA levels that exceeded the Dutch soil benchmark at all 25 sample points.

Independent scientific research (Dalmijn et al., 2025) detected EEA-NH4 — the fluorochemical currently being discharged from the Hillhouse estate — in air samples taken at Hazelrigg measuring station, approximately 20km from the site.

The 1km radius has not been explained against either the soil testing data or the airborne detection data. No modelling — of air dispersion, groundwater flow, or other transport pathways — has been published that supports the 1km figure.

What We Are Not Claiming

This post does not claim that the 1km zone is wrong, or that the area requiring advisory coverage is larger than 1km. That question requires investigation and modelling that has not been published.

What this post documents is that:

• The zone has been stated inconsistently in official documents
• No measurement methodology or map has been published
• The implementing authority redirected a direct question about the zone’s definition to another body
• The scientific basis for 1km has not been published

These are documentation gaps — questions that can and should be answered by the relevant authorities.

Questions for the Authorities

The following specific questions can be put to Wyre Council and the Environment Agency:

1. Which boundary is the 1km zone measured from — the Hillhouse estate boundary, the Technology Enterprise Zone boundary, or the AGC Chemicals Europe facility boundary?
2. From what reference point is the 1km measured (nearest boundary point, centroid, or other)?
3. What modelling or investigation supports the 1km radius as the appropriate zone for food safety advice?
4. Why has no map been published?
5. Which authority — Wyre Council or the Environment Agency — is responsible for defining the zone?

Sources: FSA/Wyre Council egg advisory, 2 February 2026 (Wyre Council); Wyre Council, 5 March 2026 (further steps statement); Dalmijn et al., ES&T 2025 (airborne detection at 20km); Wyre Council FOI response, Q5.