Many slurry stores, installed 20 - 30 years ago, are coming to the end of their reliable life. The Nitrate Pollution Prevention Regulations require farms in nitrate vulnerable zones (NVZs) to have storage for slurry of at least six months’ pig slurry production (1 October to 1 April). In non-NVZ areas the requirement is four months.
Most slurry stores will require planning permission, although smaller ones might be classed as permitted development, either with a notification for above ground tanks (Class A), or possibly without a notification for non-structural types such as small slurry bags (Class B).
Farm waste storage: guidelines for construction
A comprehensive guide to the design, construction and maintenance of slurry stores, silage clamps and fuel oil stores is available from the Construction Industry Research Association, Report 126. The new, updated report incorporates the amendment of the SSAFO Regulations in 2010, the introduction of new relevant regulations and the evolution of the construction and storage technologies. It provides up-to-date information on the selection, sizing, costs and risks associated with farm waste storage as well as on the issues that may arise during the design, construction and operation phases
Part 1 Selection guide describes the legislative context and presents the characteristics of farm wastes and principles of waste treatment and disposal. Also, it summarises the main features of the most widely used storage systems, thus helping select the most appropriate store or narrow down the choice to the suitable options. This part is intended for those people who are seeking an overview of the topic and/or advice on the selection of the store (eg the farmers).
Part 2 Design and Construction guide covers the general design, construction and installation aspects and provides specific details on the storage facilities, including, but not limited to, earth-banked lagoons, concrete stores, weeping walls, slurry bags and anaerobic digestion systems. This part also provides guidance on the maintenance and repair of structures, and health and safety considerations. It is aimed at a more technical audience, such as designers, consultants, material suppliers and contractors.
Covering a slurry store can keep rain out, and odours and ammonia in. For new stores on PPC farms, covers are mandatory. The use of covers reduces ammonia emissions during storage by up to 50% for a cover with ‘standard’ leakage and by 85 to 90% for an improved cover. A number of covering techniques are available, many of which have been developed in northern Europe.
Schematic diagram showing gaseous loss from a slurry store
The value of slurry as a replacement for manufactured fertiliser should not be ignored. By analysing slurry and applying it to suit crop requirements at the appropriate time of the year, producers can treat slurry as an asset rather than a nuisance.
Click here for AHDB guidance on the value of pig manure and slurry, including a video on slurry testing.
Grants and Allowances
Grants and allowances change on a regular basis so it is always best to check the relevant website for the most up-to-date information.