- Made in North Devon since 1973
- BSI Kitemark ready-mixed concrete
- Manufactured to BS EN 14992
- UK-wide & European delivery
Renewables · AD · process civils
AD Plant Tanks.
Sulphate-resisting. Gas-tight. Built to last 50 years.
Bespoke precast tanks, hoppers and structures for anaerobic digestion plants — reception tanks, primary and secondary digesters, digestate stores. Sulphate-resisting C40/50 concrete to BS 8500-1:2023, designed to BS EN 1992-3. Capacities 200 to 3000 m³ (7,063 to 105,945 cu ft).
AD process liquor is aggressive. We mix sulphate-resisting CEM III concrete, design to liquid-retaining code, post-tension the larger rings and seal every joint with hydrophilic waterstop. The tank that leaves Devon is the tank that lasts.
We work direct with the process designer — HZI, WELTEC, EnviTec, BTS Biogas — and with EPC contractors building farm-fed, food-waste and industrial AD plants across the UK.
- · SR C40/50
- · 200 – 3000 m³ (7,063–105,945 cu ft)
- · BS EN 1992-3
- · XA2 / XA3
- · 50-year design life
- · 8-12 week lead
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Hero — completed AD plant aerial showing primary digester, secondary digester and digestate store with green-membrane gas holder
Specification
Tank types and process structures.
AD-grade structures are always bespoke — capacities below cover the recurring families. Wall thickness, post-tensioning and waterstop detail vary with diameter and process temperature. Send us the process drawing and we will return a structural design.
| Variant | Capacity | Wall detail | Typical use |
|---|---|---|---|
| Reception / pre-tank | 200 – 600 m³ (7,063 – 21,189 cu ft) | 300mm (1ft) sulphate-resisting C40/50 | Slurry / food-waste reception with maceration |
| Primary digester wall sections | 1000 – 3000 m³ (35,315 – 105,945 cu ft) | 350-450mm (1ft2in-1ft6in) SR C40/50, post-tensioned options | Mesophilic and thermophilic anaerobic digestion |
| Secondary digester / digestate store | 1000 – 3000 m³ (35,315 – 105,945 cu ft) | 350mm (1ft2in) SR C40/50 | Pasteurisation, post-digestion, digestate buffer |
| Sandwich (insulated) wall panels | Project-specific | Inner SR + PIR core + outer leaf | Heated digesters where heat-loss is critical |
| Process hopper / dosing tank | 20 – 200 m³ (706 – 7,063 cu ft) | 250-300mm (10in-1ft) SR C40/50 | Solids dosing, liquid feedstock, retentate |
| CHP / pump house base + walls | To engineer schedule | 300mm (1ft) C40/50, plinth + bund | Engine room, pump skid, gas upgrade plant |
| Bunded leak-detection floor | Per CL:AIRE / EA design | 300mm (1ft) SR C40/50 with bentonite mat | Secondary containment beneath all process tanks |
Wall-to-floor and wall-to-wall seals use hydrophilic waterstop plus cast-in expanding sealant strip. Roof seal coordinated with the gas-holder supplier.
Each tank shipped with structural calculations, mix design and a factory cube-test record to BS EN 12390. Hydrostatic testing on site before commissioning.
AD plant references
Recent AD installations.
Photo plates being commissioned — placeholder shot briefs below.
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Aerial of erected primary digester ring with green double-membrane gas holder
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Mobile crane lifting precast wall section into place on bund slab — site context
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Reception tank with cast-in feed hopper and macerator penetration ducts
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Bund slab cast around tank ring with bentonite mat and sump kerb visible
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Close-up of wall-to-floor joint showing hydrophilic strip and cast-in sealant
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Sectional cut showing inner SR leaf, PIR core, outer leaf
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CHP engine base on AD plant with vibration mounts and gas conduits
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Curved wall section curing in mould at Holsworthy yard, post-tension ducts visible
Where they go
Common applications.
From a 500 m³ (17,658 cu ft) farm-fed AD on a Cornish dairy to a 3000 m³ (105,945 cu ft) food-waste plant in the Midlands, we cast the structures and coordinate with the process designer and the EPC contractor.
- · Farm-fed AD plants — slurry, FYM, energy crop digesters
- · Food-waste AD — depackaging plant, source-segregated FW
- · Wastewater treatment digesters — sludge mesophilic plant
- · Industrial process AD — distillery, brewery, dairy effluent
- · Digestate storage and pasteurisation tanks
- · Biomethane upgrade plant pump and compressor bases
- · Slurry separator and screw-press housings
Standards & references
Cast to current code.
- BS EN 1992-3
- Eurocode 2 — design of liquid-retaining and containment structures.
- BS 8500-1:2023
- Concrete specification — sulphate-resisting C40/50, exposure XA2/XA3.
- BS EN 13369
- Common rules for precast concrete products — Factory Production Control.
- EA / SSAFO 2018
- Silage, slurry and agricultural fuel oil regulations — secondary containment.
- CL:AIRE / EA guidance
- Bund design and leak-detection — 110% of largest tank or 25% of group.
Configure your AD plant
Send us the process drawing and feedstock data — we will return a structural concept and budget within five working days.
Related products
Often ordered alongside.
Common questions
What AD developers ask.
Five questions we answer most weeks. If yours is not here, ring the yard.
Why sulphate-resisting concrete on AD plants? +
Anaerobic digestion produces hydrogen sulphide and a sulphate-rich liquor. We cast tanks for AD service in sulphate-resisting C40/50 to BS 8500-1:2023, exposure XA2 / XA3, with CEM III/A or CEM III/B blended cement. We also coat the exposed face with a chemical-resistant epoxy or HDPE liner where the design calls for it. Service life designed to 50 years per BS EN 206.
What size of digester can you build in precast? +
Our system covers 200 m³ (7,063 cu ft) reception tanks up to 3000 m³ (105,945 cu ft) primary digesters. Above 1500 m³ (52,973 cu ft) we typically post-tension the wall ring with horizontal cables in cast-in ducts. Larger digesters are jointed on a vertical seal detail with a hydrophilic waterstop. We have built single-tank installations and multi-tank cascade plants.
Do you do the bund and leak-detection floor too? +
Yes — we cast the bunded slab beneath the tank to Environment Agency / CL:AIRE secondary-containment guidance. Typical detail is a 300mm (1ft) SR concrete slab with a bentonite mat below and a leak-detection sump cast into the bund kerb. Capacity sized to 110% of the largest tank or 25% of the tank group total, whichever is greater.
How are the tanks made gas-tight? +
Wall-to-floor and wall-to-wall joints use a hydrophilic waterstop plus a cast-in expanding sealant strip. Roof seal is project-specific — single-membrane gas holder, double-membrane store, or fixed concrete roof with gas-take-off. We work with the AD process designer (HZI, WELTEC, EnviTec, BTS, etc.) on the seal schedule.
What is a realistic programme? +
A typical 2000 m³ (70,630 cu ft) digester runs 8-12 weeks from drawing sign-off to final wall section despatched. Erection on site adds 2-3 weeks for the tank ring and another 1-2 weeks for the roof. Programme depends on whether the bund slab is in-situ or precast — we can do either. Pre-order long-lead post-tensioning hardware as soon as the design is locked.
How would you like it?
Supply-only or fitted — AD Plant Tanks
Supply only
Per-unit / per-metre supply
Lead time: 8–12 weeks per digester
- Cast wall sections, hoppers, bund elements
- Hydrophilic waterstop, sealant strips, fixings
- Structural design + cube-test data
- Delivery on extendable trailer
- On-site mobile crane (specified by EPC)
- In-situ floor slab and bund pour
- Gas-holder roof and process plant
Fitted (supply + install)
Supply + install crew
Lead time: 12–16 weeks (incl. erection)
- Everything in supply only
- Specialist erection team coordinated by WCCP
- Joint sealing, post-tensioning, hydrostatic test prep
- Process pipework, pumps, CHP and gas upgrade
- Permitting and EA application
. AD work is always bespoke — we coordinate from process drawing through to hydrostatic test against the EPC programme.
Ready to spec it?
Send the process drawing and feedstock data — we will return a structural concept and budget.