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New General Binding Rules on Silage & Slurry - Frequently Asked Questions

We've collated the answers to some of the most frequently asked questions about the new General Binding Rules around silage and slurry.

Position on adaptions to precision spreading equipment for slurry and liquid digestate applications.

The addition of small splash plates to the end of pipes on dribble bars/trailing hose spreaders is not deemed to be a Low Emission spreading method.

The small splash plates will spread the slurry over a greater surface area of the ground and this will increase nitrogen losses to air in the form of ammonia emissions. Increased ammonia emissions also mean that less nitrogen is retained on the soil for grass/plant growth, resulting in lower nutrient use efficiency.

Therefore, the addition of small splash plates on the end of pipes on dribble bars/trailing hose spreaders would not be compliant with the General Bind Rule (GBR) 18 which requires slurry and liquid digestate to be applied using precision equipment.  By precision equipment the GBR’s means equipment capable of low emission, accurate application techniques including a dribble bar or band spreader, trailing hose, trailing shoe or direct injection. Dribble bars, trailing hose and trailing shoe methods spread slurry and liquid digestate in narrow bands/lines on the ground which reduces the surface area of the slurry or liquid digestate exposed to the air. This reduces ammonia emissions and retains more nitrogen on the soil for grass/plant growth.

The GBR requires precision equipment to be used by all spreading contractors, dairy farmers milking more than 100 cows, beef farmers with more than 200 livestock units and anyone applying liquid digestate on land.  By 1st January 2027 all Scottish livestock farmers producing slurry must use precision equipment for the application of slurry.

Will I need an engineer’s certificate to prove my existing slurry/silage store is up to standard?

All structures built after 1 September 1991 would have needed an engineer’s certificate or sign-off as part of the SEPA prior notification procedure so in most instances SEPA will already be aware of these.  Going forward this rule does not apply to facilities in existence prior to the new regulations coming into force.  However, sign-off may be required if that was a condition or requirement of grant funding.

If I’m putting up a new slurry store, should I be looking to cover it, in case of future amendments?

These regulations don’t require a cover but there are advantages to having a cover, not least less collection of rainfall which takes up capacity and time / expense handling and spreading. It may be cheaper to install a roof at the initial construction phase rather than retrofitting one.

Can imported digestate and farm produced slurry be kept in the same store?

The rules allow for slurry to be stored in a digestate storage system and vice versa, the important aspect is that the stores meet the necessary standards and have adequate capacity. This would mean by 2026 the land manager would need to have a minimum of 22 weeks capacity for the amount of cattle slurry produced on farm during the housing period and also for quantity of digestate imported onto the farm during this period.

Is the 22-week/26-week storage requirement for the whole farm or is it site specific?

The 22/26 weeks is a whole farm requirement for slurry storage.

Does an earth bank silage pit have to have a block wall at the base of the earthed sloped walls?

Not necessarily, this will depend on the requirements of the engineer.

Will a 'Moscha' swivel splash plate meet the precision slurry application requirement?

The 'Moscha' swivel plate has been categorised as a splash plate which throws slurry into the air.  Along with high trajectory splash plates and rains guns these will be banned from 1st January 2023.

What funding is available for farmers to invest in slurry storage and precision spreading equipment?

AECS will be available for slurry storage until 2024. Further funding for precision equipment and slurry storage will be a decision for Scottish Government.

What silage pit flooring materials are acceptable? Is there a certain depth of concrete, asphalt you expect to see?

The engineer will need to ensure the floor is designed appropriately to meet the appropriate British Standards.  The most common materials used for silage pit floors and Hot Rolled asphalt and reinforce concrete.

In regard to the requirement for an engineer’s sign-off certificate, would an agricultural engineer be appropriate?

The regulations refer to an ‘engineers sign-off’ but does not specify further.  Providing the agricultural engineer is qualified to give professional advice in relation to the construction project this would satisfy the rules.  It is also advisable to ensure the engineer has appropriate insurance cover.

Is there a list of engineers that are accredited to sign off any new slurry works?

No - any qualified engineer can design and sign off the development.  Either the engineer can use their own sign off certificate or there is an engineer sign off certificate available on the SEPA webpage.

For farms that meet the precision spreading equipment exemptions from 1 Jan 2023 - 1 Jan 2027, what splash plates will be allowed for these farms?

Farmers and crofters who meet the exemption criteria will be able to use an inverted splash plate until 1st January 2027.  All other forms of splash plates (high trajectory and Moscha swivel plate) and rain guns will be banned from 1st January 2023.

What will the phasing in period look like? Will it be a cranking up of regulations over four years or will it be advisory to allow time to change?

The phasing period for the changes starts on 1st January 2022.  From 1st January 2022 SEPA will be working the SRUC and NFUS to produce guidance for farmer regarding these changes so by January 2027. Most famers in Scotland are at or are working towards attaining a compliant status.  SEPA will, in a pragmatic manner, work with farmers who have difficulty complying with the phased implementation of the rules.

Some concerns from those with less than 22/26-week capacity have been spreading slurry throughout the winter without any pollution issues for decades, why is there a one-size fits all policy for all of Scotland?

There has always been a one size fits all for Scotland, currently all livestock farmers if they had been complying with SSAFO should have had 180 days storage capacity for slurry (26 weeks).  Scottish Government felt it best to have one set of rules for slurry storage capacity across Scotland, so reduced the minimum capacity to 22 and 26 weeks to mirror the requirements in the NVZ regulations. Farmers must ensure they are complying General Binding Rule 18 when applying organic and inorganic fertilisers.

The rules say "the operator must notify SEPA no later than 30 days prior to commencing the works". What should the operator provide and what is commencement of works?

The phasing period for the changes starts on 1st January 2022.  From 1st January 2022 SEPA will be working the SRUC and NFUS to produce guidance for farmer regarding these changes so by January 2027. Most famers in Scotland are at or are working towards attaining a compliant status.  SEPA will, in a pragmatic manner, work with farmers who have difficulty complying with the phased implementation of the rules.

Over what time period will the stock unit figure be calculated? The number of stock will vary almost on a daily basis on some farms. There could be points during the winter housing period when a farm could be above 200, but on average they could be below.

The stock figure will be calculated based on the number of livestock being housed during the winter period when the ability to spread slurry is reduced, due to weather, ground conditions and crop requirement.

Will they [stock unit numbers?] trigger the requirement to have the precision equipment on 1 Jan 2023?

If a contractor is spreading slurry on behalf of the farmer as of 1st January 2023 the slurry must be applied using precision technics.  If a dairy farm is miking more than 100 cows and a beef unit has more than 200 livestock units and they produce slurry then the slurry must be applied using precision technology on or after 1st January 2023.  On and after 1st January 2027 all slurry produced on farm, no matter of type or size, must be applied by precision application methods.

Do calves equate to 0.5LU as soon as they are born?

Yes, they are classed as livestock under 2yrs of age.

For the splash plate requirements, is it 800 sows or 800 fattening pigs?

If a farmer has 800 or more sows on a slurry based system, then precision application equipment must be used, similarly if his neighbour has 800 fattening pigs or more on a slurry based system he too would have to use precision equipment for land application.

Is it likely that a derogation for the application of a proportion of slurry via a splash plate on each holding could be acceptable, demonstrated with RAMS, rather than having to use precision application equipment across the whole of the farm? This would give those with small fields at a significant distance from the steading more scope for getting slurry out across the whole of the farm?

It is unlikely SG would allow such a derogation. In Northern Ireland where field sizes are significantly smaller than in Scotland farmers have successfully been using precision technology for field application of slurry for two to three years.  Contactors using a dump station are becoming more common in Scotland; instead of spreading using a vacuum tanker and splash plate the vacuum tanker brings slurry to the dump station from where it is pumped to a precision spreader in the field which allows land away from the farm to be fertilised with slurry.

For cattle stored on bedded systems – how does that fit with the storage requirements? How do you evidence it?

For the purpose of this question, by bedded systems we are assuming straw bedding and the farm producing FYM.  The farmer has the option to store the FYM either in temporary field heap middens in the field or alternatively in a dungstead/midden with impermeable floor and effluent tank.  The liquid fraction produced from the midden is termed slurry and must be collected, this will require some farmers to provide additional capacity to collect winter run-off from the midden or divert it to a suitably sized / designed constructed farm wetland.

In what scenario are the walls of a slurry storage tank not impermeable?

This situation arises when livestock are on a slurry-based system which is scraped daily to a concrete slurry lagoon/ tank which has a weeping wall or a couple of weeping wall which in some circles is referred to as a weeping walled midden.  Alternatively, this also refers to High Level Slatted building where the end wall is designed to let the liquid fraction seep through timber / concrete sleepers.  In these circumstances the liquid fraction seeping through the wall is slurry and must be collected in channels and transferred to suitable sized impermeable tank.

Can you give an example of “substantially reconstructed”?

There is no change to the regulatory requirements in this respect.  An example would be replacing 25% or more of the wall panels of a slurry store.

With a small herd, we were looking at using a slurry bag for dairy washings. Would we need any groundworks?

The Controlled Activities Regulations allow for the use of slurry bags on farms.   All slurry bags must be impermeable, have sufficient strength and integrity to last 20 years and are unlikely to burst or leak when in use.  The slurry bag must be situated within a bund which is of at least the equivalent capacity of the slurry bag, the bund must be lined with an impermeable sheet material through which slurry cannot permeate for a period of 20 years and have a means of removing rainwater without the walls or base of the bund being penetrated with any pipes or valves.

I have 300 head of beef cattle on a straw bedded system; we don’t produce slurry/have slurry tanks. I do spread silage effluent, currently using a splash plate. Do I need to use precision application equipment for silage effluent application going forward?

The Regulations only require the spreading of slurry and anaerobic digestate to land by means of precision application equipment.  Silage effluent can still be spread to land using a splash plate in accordance with GBR 18.

How will the 22 week slurry storage capacity will be measured and policed for each business? The start of winter housing can vary from farm to farm. Numbers also fluctuate during housing. Or will it simply be policed by penalising farmers who are spreading when ground conditions are not suitable?

The 22 weeks capacity will be based on the number of livestock producing slurry when housed over the winter months.  One also needs to account for the volume of any runoff from the midden, silage pits, any washings and or contaminated yard drainage which is being collected in the slurry system during this time.  There is no difference on how this is calculated now compared to when the SSAFO regulations were introduced in 1991.

For example if a farmer has 250 beef livestock units and has 150 of these housed on a slurry based system then he would need to provide 22 weeks for the slurry produced by the 150 livestock plus any other liquid that may be being collected in this system such as winter run-off from a silage pit or midden.  The slurry figures used to calculate the 22 weeks capacity are standard Scottish Government figures used in PLANET Scotland for NVZ’s.

The GBR’s are the minimum legal requirement for operating.  All farms where slurry is produced will be required to have 22 weeks slurry storage capacity by 1st January 2026.  SEPA will work with those farmers we come across during routine farm work who have less than 22 weeks after 1st January 2026 with the aim to get them into compliance as quickly as possible.

For farmers with bedded courts and slats, what is meant by the 200 beef livestock units in relation to slurry spreading? For example if a farmer has 400 beef cattle but only 80 on slats, do they have to adopt precision spreading by January 2023 or do they have until January 2027?

We have sought clarification from Scottish Government and checked the original consultation for further details.  The Scottish Government acknowledged in the consultation that, although, the aim is for all slurry and liquid dig estate in Scotland to be applied by precision methods, it was appreciated that there may be financial implications for smaller enterprises in the in the short term.  It was therefore proposed in the consultation that a phasing-in period be implemented in support of these enterprises, with a total ban coming into effect 5 years from the date of the regulations coming into force.  Small farm businesses were identified by the herd number thresholds proposed in the consultation; these herd number thresholds are now reflected in the Regulations.

The Regulations refer to the number of beef livestock units on the farm, or milking cows.  They do not distinguish between those on slurry and those on straw courts, as these were the threshold levels above which the farm was deemed to be a large unit in relation to compliance timescales.  Consequently, if a farm has over 200 beef livestock units or 100 milking cows any slurry produced on these units needs to be applied to land using a precision technique from 1st January 2023.

Scottish Government advise farm businesses to take advantage of the Sustainable Agricultural Grant Scheme support for low emission spreading equipment wherever possible to minimise the investment implications for the business.  Precision application techniques ensure that the loss of available nitrogen, as ammonia emissions, is minimised benefitting the farmer, protecting Scotland’s water environment and reducing the agricultural impact on climate change and air quality.

I have recently purchased a dribble bar and after using have noticed the lines appear to leave slurry on the sward with grass not growing well. Can I adapt the dribble bar by adding a shoe / small plate like the “splash it shoe” to each of the dribble bar pipes to improve the even spread of slurry?

The Water Environment (Controlled Activities) (Scotland) Amendment Regulations 2021 made the following amendments to General Binding Rule 18 (GBR18) in Schedule 3 of the Water Environment (Controlled Activities) (Scotland Regulations 2011 regarding the application of slurry and liquid digestate.

(o) slurry and liquid digestate must be applied using precision equipment.

“precision equipment” means equipment capable of low emission, accurate application techniques including a dribble bar or band spreader, trailing hose, trailing shoe or direct injection

The Scottish Government regards precision equipment with low emission, accurate application techniques as those that apply slurry and liquid digestate directly onto or into the ground and not into the air. Techniques augmenting precision application equipment to spray / spread slurry or liquid digestate are not considered “precision equipment” under the Water Environment (Controlled Activities) (Scotland) Regulations GBR18.

Scottish Government will consider research evidence on new slurry and liquid digestate application techniques such as “the splash it shoe” before approval as “precision equipment”, capable of low emission and accurate application techniques, as defined by the Water Environment (Controlled Activities) (Scotland Regulations 2011.  Research should demonstrate that the dribble bar adaptation is capable of lowering emissions when compared to broad cast applicators such as a splash plate.

Find our more about what's changed, including the timelines for the transitions on our  New General Binding Rules on Silage & Slurry - What's changed? webpage.