Regulatory Decision 088: Storing and dewatering non-hazardous iron ochre sludge from abandoned coal mines
This Regulatory Decision (RD) is valid until 1 June 2025 by which time it will be reviewed. You should check back at that time to ensure the RD is still valid.
NRW can withdraw or amend this RD before the review date if we consider it necessary. This includes where the activities that this RD relates to have not changed.
Regulatory Decision
This RD only applies to storing and dewatering non-hazardous iron ochre sludge produced from treating discharges to water from abandoned coal mines in Wales.
Iron ochre is a liquid sludge consisting of iron hydroxide (Fe(OH)3) which is produced in settlement systems during treatment of mine waters from abandoned coal mines.
The sludge must be dewatered in a purpose-built drying bed at a site controlled by the Coal Authority or their contractors.
It applies to iron ochre sludge that is:
- produced on site
- imported from another mine water treatment site controlled by the Coal Authority or their contractors
Conditions you must comply with
You must:
- store and dewater iron ochre sludges at a site which is controlled by the Coal Authority or their contractors
- store and dewater iron ochre sludge in a secure place with no public access
- store and dewater iron ochre sludge in purpose-built sludge drying beds which are engineered to prevent pollution, and where any water at the base of the bed is collected and drained back to the treatment scheme at an appropriate location
- prevent run-off from the surface of the drying bed during heavy rain
- prevent pollution from any water produced at the base of the drying bed
- contact the Natural Resources Wales’s Area Mine Water Lead before you import iron ochre sludge from another site providing the agreed details
- only import iron ochre sludge from another site in compliance with a method statement which minimises the risk of pollution
- keep records to show that you have complied with this RD and make these records available to the Natural Resources Wales on request
- ensure that the onward disposal or recovery of the treated ochre sludge must be at a permitted disposal/recovery site following the necessary waste characterisation and classification
- ensure that the waste Duty of Care is followed for the movements of waste
You must not:
- exceed the safe operating capacity of the sludge drying bed at any time
- import more than 15,000m3 of non-hazardous iron ochre sludge for dewatering to any one site within any calendar year
Enforcement
This RD does not change your legal requirement to have an environmental permit for a waste operation when storing and dewatering non-hazardous iron ochre sludge from abandoned coal mines.
However, NRW will not normally take enforcement action if you do not comply with the need for an environmental permit if you meet the requirements in this RD.
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
Contact your Area Natural Resources Wales’s Mine Water Lead before you import iron ochre sludge from another site.