Slurry lagoon lining around Nottingham

Livestock and digestate in Nottinghamshire

South-east of the city, the grassland of the Vale of Belvoir and the Smite and Devon valleys carries dairy and beef herds. Further north, arable farms around Southwell, Newark and Retford feed crops and food waste into AD plants, and the digestate comes back out to be stored before it goes on the land.

Both need sealed storage sized for the months when spreading isn't allowed. That storage is the part we line, for farmers, AD operators and the consultants who design the stores.

Why sandstone ground raises the stakes

Much of the county sits on Sherwood Sandstone, an aquifer used for public supply. A leaking store on that rock doesn't just stain the soil; it can reach groundwater. That is one reason designers here go for two liners with a seepage layer sandwiched between them, so any seepage through the primary is caught and shows at an inspection point.

On the mudstone further east, the worry is more often a nearby watercourse such as the Smite, the Devon or the Trent itself. A welded liner anchored at the crest keeps the contents inside the banks either way.

New stores and tired old ones

On a new build, the earthworks firm shapes the embankments, floor and crest trench, and we hold a tape and level against the lining drawing before any roll is delivered. On an older store with earth banks, the farm pumps it out and washes it down, any slumped bank is rebuilt, and our liner goes in over new protection.

• 300gsm non-woven fleece laid first, between ground and sheet
• HDPE or LLDPE fused panel to panel, one layer or two as drawn
• A seepage drainage layer and detection point on double-lined stores
• Fill and pump-out pipes and a level gauge, each booted through the sheet
• A floating cover if the permit or designer requires it

Paperwork an inspector will read

Every Nottinghamshire lagoon gets a logged trial weld on the day we fuse it. Afterwards the farm or AD operator holds a folder covering the products used, every weld record and the as-built drawings, which is the evidence an inspecting officer or an insurer will want to work through when they visit the farm.