Compliance Assessment Scheme

As Scotland's environmental regulator, we issue a range of licences designed to control activities that could lead to pollution or environmental damage. Compliance with these licences is important in ensuring that the environment and human health are protected.

We believe that the industries and businesses we regulate should find it as easy as possible to understand their responsibilities; enabling them to comply with the regulations and realise the many economic benefits of good environmental practice.

Our Compliance Assessment Scheme (CAS) has been designed to demonstrate the level of compliance associated with specific licence conditions.

The Compliance Assessment Scheme applies to our four principal regulatory regimes namely:

Regulatory regimes in CAS
  • Pollution Prevention and Control Regulations (PPC) - Part A and Part B
  • Waste management licensing (WML)
  • Controlled Activity Regulations (CAR) - Point source and water resources
  • Radioactive Substances Act (RSA)


These regulatory regimes cover industrial processes; waste treatment and disposal; emissions to air; discharges to water, abstraction and impoundment of water and radioactive substances.

The scheme was first introduced in 2009 for sites covered by the Pollution Prevention and Control Regulations and has been phased in to cover approximately 10,000 licences. We use a risk based system to identify which sites get a site based inspection in any given year. The highest risk sites and poorly performing sites receive multiple site based inspections per year and the lowest risk sites receive a site based inspection every five years. The results of our sampling, site data returns and desk based inspections are also used to calculate the annual compliance result. Should a site have an environmental incident this is also fed into the scheme along with any subsequent follow-up inspections.

Because of the risk based system the number of sites reported within the scheme fluctuates year-on-year.

In addition to the annual published result, we publish inspection reports for those regulated under Part A of the Pollution Prevention and Control (Scotland) Regulations 2012 (PPC 2012). The report is displayed for those sites with an inspection carried out from 1 January 2014. Reports are updated on the results page periodically. The result of the inspection contributes towards the overall Compliance Assessment Scheme score for that year (e.g. 12/06/2016 will count towards the 2016 assessment score). Should you require further information on how we assesses compliance, please refer to Compliance Assessment Scheme.