How GeoScreen Works — The Technology Behind a 90-Second Ground Risk Report

When people hear that GeoScreen delivers a Tier 1 Preliminary Ground Risk Screening Report — a fully automated desk-based assessment — in around 90 seconds, the first question is simple:

How?

A manually produced desk study typically takes a competent geotechnical engineer one to two days. What GeoScreen does differently is not simpler — it is faster, parallel, and structured.

Here’s what’s actually happening under the hood — and, since several of you asked, exactly which datasets get interrogated along the way.

Step 1 — Geocoding

When a site reference is submitted — postcode, address, or grid reference — GeoScreen queries the Ordnance Survey Names API to resolve it to a precise OS National Grid Reference (easting and northing).

This coordinate becomes the anchor for every subsequent data query. At the same time, the system identifies the relevant Local Planning Authority.

This step typically completes in under one second.

Step 2 — Parallel Data Retrieval

GeoScreen then queries more than twenty publicly available datasets simultaneously — all in parallel rather than sequentially. Each answers a specific question about the ground, the setting, or the constraints on a site.

Geology and ground conditions

BGS 1:625,000 bedrock and superficial geology — the rock and near-surface deposit types that drive most geotechnical behaviour, from compressible alluvium to shrink–swell clays to soluble strata
BGS Single Onshore Borehole Index (SOBI) — historical ground investigation records within 500m
BGS geological fault data — mapped faults within the study area
BGS GeoIndex hydrogeology — the aquifer designation (Principal, Secondary A/B, or Unproductive)
BGS 1km non-coal mining hazard grid — vein minerals, chalk, evaporites and building-stone mining potential
BGS / UKHSA radon potential — the radon class, which determines whether protective measures may be required under BR 211

Sample BGS bedrock geology figure — Sample output — BGS bedrock (left) and superficial (right) geology figures, Tier 1 report, Bath BA1 2LY. Every figure carries a north arrow, scale bar and title bar.

Sample BGS superficial geology figure — Sample output — BGS bedrock (left) and superficial (right) geology figures, Tier 1 report, Bath BA1 2LY. Every figure carries a north arrow, scale bar and title bar.

Mining

Mining Remediation Authority (MRA) data — Development High Risk Area designation and recorded mine entries: shafts, adits and shallow workings

Flooding and water

EA Flood Map for Planning — river and sea flood zone (FZ1/2/3)
EA surface water flood mapping (NAFRA2) — pluvial flood risk, assessed separately from river flooding
EA Source Protection Zones — proximity to groundwater abstraction protection zones
EA WFD river and canal water bodies — identifies the named receiving watercourse

Sample EA Flood Map for Planning figure — Sample output — EA Flood Map for Planning figure, Tier 1 report, Bath BA1 2LY.

Sample EA Source Protection Zones figure — Sample output — EA Source Protection Zones, Tier 1 report, Bath BA1 2LY.

Land use and contamination

EA Historic Landfill Register — over 19,000 closed landfill sites within 500m, many with no surface expression; feeds the ground gas assessment and Conceptual Site Model
EA Permitted Waste Sites — currently authorised landfill and waste facility boundaries
EA Environmental Permitting Register — regulated facilities within 1km (industrial installations, waste operations, discharges), including minewater discharge consents cross-checked against MRA mapping
OpenStreetMap, via the Overpass API — petrol filling stations within 500m, active and recently closed. Exempt from environmental permitting and absent from every EA register, yet a recognised potential hydrocarbon source (underground storage tanks)
OpenStreetMap, via the Overpass API — sensitive infrastructure and land uses: gas holders, sewage and water treatment works, sub-stations and power stations, emergency services, military, aviation, port and quarry sites

Sample permitted regulated facilities figure — Sample output — permitted regulated facilities and historic landfill within 1km, Tier 1 report, Bath BA1 2LY.

Terrain

EA National LiDAR 1m Digital Terrain Model — a hillshaded terrain model revealing how the site sits in the landscape, and subtle anomalies (made ground, former quarrying, infill) not visible on a standard basemap

Heritage and ecology

Historic England NHLE — listed buildings, scheduled monuments and conservation areas within 500m
Natural England datasets — SSSI, SAC, SPA, Ramsar, AONB and National Park designations

Historical mapping

National Library of Scotland historical OS maps — three epochs (c.1885 [1885–1903], 1888–1913 and 1919–1947), analysed by AI to identify former industrial use, pits, ponds and made ground of geotechnical or environmental significance

Sample historical OS mapping figure — Sample output — historical OS mapping (1885–1903 epoch) via the National Library of Scotland, Tier 1 report, Bath BA1 2LY.

Because all queries are executed concurrently, the entire data-gathering phase typically completes within 15–20 seconds.

Step 3 — Hazard Assessment (the RAG Engine)

GeoScreen’s rule-based RAG (Red–Amber–Green) engine then processes the retrieved data.

Eleven geohazards are assessed:

Mining Legacy, Compressible Ground, Shrink–Swell Clays, Slope Instability, Dissolution Features, Made Ground, River and Coastal Flood Risk, Surface Water Flood Risk, Radon, Ground Gas, and Aggressive Ground. Proximity to an EA Source Protection Zone is also reported. (Unexploded Ordnance screening is planned for a future release and is not part of the current Tier 1 assessment.)

Each module outputs:

A hazard rating (Low, Medium, High, or Very High)
A corresponding data confidence level
A recommended action

These results are aggregated into an overall site risk rating using defined logic. For example:

A single Very High hazard drives an overall Very High rating
Multiple Medium hazards may combine to produce a High overall rating

The key point is consistency: every site in England is assessed using exactly the same rules.

Sample geohazard risk assessment summary table — Sample output — geohazard risk assessment summary, Tier 1 report, Bath BA1 2LY. Radon drives the overall Very High rating.

Step 4 — Figure Generation

While hazard assessment runs, GeoScreen generates fifteen annotated map figures (Appendices A–O) in parallel.

These include:

Site location plan
BGS bedrock and superficial geology
Environment Agency river and coastal flood mapping
Surface water flood risk (NAFRA2)
Heritage and ecology constraints
Mining Remediation Authority data
Radon potential
Groundwater source protection zones
EA LiDAR terrain model
Permitted regulated facilities and historic landfill
Historical OS mapping (c.1885, c.1888–1913, c.1919–1947) from the National Library of Scotland

Each figure includes a north arrow, scale bar, and title bar. Historical maps are also analysed using AI to highlight features of potential geotechnical or environmental relevance.

Sample BGS/UKHSA radon potential figure — Sample output — BGS/UKHSA radon potential figure, Tier 1 report, Bath BA1 2LY. The site sits in a Class 5 radon area.

Step 5 — AI Narrative Generation

Sixteen report sections are generated concurrently using the Anthropic Claude API.

These cover:

Site setting and planning context
Heritage and ecology
Geology and hydrogeology
Individual geohazard assessments
Foundation considerations
Conclusions and recommendations
Executive summary

Each section is generated using a structured prompt that injects site-specific data and applies over fifty language and logic rules.

The AI generates the wording. The rules — defined by a Chartered Geotechnical Engineer — determine the outcome.

Step 6 — Assembly, QA, and Delivery

All components — narrative, figures, tables, and structured data — are assembled into a professional DOCX report.

The report is then passed through automated QA checks and issued to the client by email.

Total elapsed time: typically 70–90 seconds from submission to delivery.

What GeoScreen Is — and What It Is Not

A GeoScreen Tier 1 report is a controlled, rule-based geotechnical decision-support product.

Every output — hazard ratings, geological descriptions, planning constraints, and recommendation statements — is derived from explicit, documented logic applied consistently to publicly available data.

It is not a substitute for a Chartered Geotechnical Engineer’s professional judgement on a complex site, and every report recommends a professional desk study where one is required.

But for early-stage feasibility, multi-site screening, and pre-acquisition decision-making, it provides a level of speed, consistency, and accessibility not achievable through traditional workflows.

Explore GeoScreen

Sample Tier 1 reports for sites across England — including High-risk and Low-risk examples — are available to download at geoscreen.uk.

A Tier 1 Preliminary Ground Risk Screening Report is available from £150 + VAT (£180 inc. VAT), with results delivered by email in around 90 seconds.

A Tier 0 Ground Risk Snapshot — RAG ratings and all figures without the full narrative — is also available from £75 + VAT.

Tristan Morgan BSc (Hons) EurGeol CGeol FGS AMICE is a UK Registered Ground Engineering Specialist and Director of Magnum GSI Ltd. GeoScreen™ is an automated ground risk screening platform available at geoscreen.uk.