This regulatory position statement (RPS) does not change your legal requirement to have an environmental permit for a waste operation and groundwater activity when you use unbound incinerator bottom ash aggregate (IBAA) in:

• building a road, cycleway or pathway sub-base
• building a structural platform
• pipe bedding

However, the Environment Agency will not normally take enforcement action against you if you do not comply with this legal requirement provided that:

• your activity meets the description set out in this RPS
• you comply with the conditions set out in this RPS

In addition, your activity must not cause (or be likely to cause) pollution of the environment or harm to human health, and must not:

• cause a risk to water, air, soil, plants or animals
• cause a nuisance through noise or odours
• adversely affect the countryside or places of special interest

Activity this RPS applies to

This RPS applies if you use unbound IBAA in construction, including when you store IBAA for that use.

Conditions you must comply with

The IBAA must:

• be derived from processed municipal waste incinerator bottom ash
• be unbound non-hazardous, waste code 19 12 12
• comply with BS EN 13242 or any revision of that standard
• if blended with non-waste aggregate, the total tonnage of the blend must meet the limits and conditions in this RPS

All uses

For each delivery of IBAA to the site of use, the end-user must get in writing from the supplier:  

• date of delivery
• name and contact details of the producer and distributors (as applicable), including the site of production address
• quantity supplied (by weight or volume)
• the end user must keep records for 2 years to show that you have complied with this RPS and make these records available to the Environment Agency on request

You must only store IBAA in the open.

You must not:

• store IBAA pending use for more than 6 months
• store more IBAA than you need
• store or use IBAA within a groundwater source protection zone 1 or 2
• store or use IBAA within 50 metres of any spring or well, or any borehole used to supply water
• use IBAA below the water table
• use IBAA underneath any residential building or garden

Building a sub-base for a road, cycleway or pathway

You must construct the surface of a road, cycleway or footpath with an asphalt or other low-permeable material.

You must not:

• install a sub-base more than 40 metres wide
• install a sub-base more than 0.7 metres deep

Building a structural platform

You must not build a structural platform:

• that is on average more than 1 metre thick
• that has less than 95% coverage with a low permeability surface or building
• within 25 metres of a surface water body
• unless it complies with the restrictions set out in the following table

Distance to surface water body (metres)	Maximum tonnage (tonnes) (Dry)	Volume after compaction at 1.7t/m3 (m3)	Maximum surface area of a structural platform (m2)
25 to 49	4,420	2,600	2,600
50 to 99	6,800	4,000	4,000
100 to 149	13,600	8,000	8,000
150 to 199	20,400	12,000	12,000
200 to 249	25,000	16,000	16,000
250 to 299	34,000	20,000	20,000
300 to 349	40,800	24,000	24,000
350 to 399	47,600	28,000	28,000
400 to 449	54,400	32,000	32,000
450 to 500	61,200	36,000	36,000
More than 500	68,000	40,000	40,000

Pipe bedding

You must use a low permeability surface above the pipe-run with adequate falls to prevent standing water.

You must not:

• store and use more than 510 tonnes in total of IBAA as pipe bedding in any single construction project and pipe run
• use IBAA as pipe bedding more than 0.3 metres deep in a trench more than 2 metres wide
• use the IBAA as a drainage medium

Things to note

We are consulting on a new standard rules deposit for recovery permit for the use of IBAA. We will publish this new standard rules permit alongside a new RPS which we consider is potentially suitable to be an exemption for a waste and groundwater activity under the Environmental Permitting (England and Wales) Regulations 2016. Once the new standard rules permit and RPS are published, we will withdraw RPS 247.

Unbound IBAA includes IBAA in hydraulically bound mixtures, where IBAA is mixed with water and a binder such as cement.

A surface water body is a relevant territorial water, coastal water, or inland freshwater (as defined by the Water Resources Act 1991).

A structural platform is an engineered base for an overlying construction feature, for example a:

• building
• car park
• retaining wall
• storage tank
• road or pavement

Pipe bedding is material laid in the bottom of a trench that has been excavated for drainage pipes or other pipelines.

A combination of the types of construction activities described in this RPS may take place on the same development. Where this occurs, you must meet the criteria specified in this RPS (for example, maximum width or thickness) for each individual construction component. 

Temporary construction features must meet all the criteria and limits set out in this RPS.

When you must check back

The Environment Agency will review this RPS by 30 September 2025.

The Environment Agency can withdraw or amend this regulatory position before the review date if they consider it necessary. This includes where the activity that this RPS relates to has not changed.

You will need to check back from time to time, including at and before the review date, to see if this RPS still applies.

This RPS remains in force until it is removed from GOV.UK or is otherwise identified as having been withdrawn.

You can subscribe to email updates about this RPS. These will tell you if the RPS has changed and when it has been withdrawn.

If you cannot comply with this RPS

If you operate under this RPS but can no longer comply with it, you must:

• stop the activity to which this RPS relates
• tell the Environment Agency immediately by emailing enquiries@environment-agency.gov.uk with RPS 247 in the subject

Contact the Environment Agency

If you have any questions about this RPS, email enquiries@environment-agency.gov.uk and put RPS 247 in the subject.