All excavations must undergo both Desk-based and Site-based risk assessments. The Site-based risk assessment determines the likely presence of contamination and is used to determine the classification of the waste prior to removal from site. This is the foundation of SWUK waste classification protocol. The Desk-based risk assessment and any laboratory analysis conducted as part of the protocol do not affect how the waste is classified, these are used to build a more robust data-set for future use.

Different waste streams must be kept separate on site and during transport. For example, asphalt and sub-base segregation is required at all times. Mixing of waste streams is not permitted under the protocol, although they can be transported on the same vehicle.

To maintain and verify the accuracy of the risk assessment process, a percentage of waste must be sampled and tested in a laboratory. The required number of tests is based on 1% of the qualifying excavations carried out two years earlier (e.g. sample numbers for 2025 are based on 2023 Street Manager data). However, this percentage may increase in future years if the correlation between lab results and risk assessments falls below 93%. The more accurate the assessments, the fewer tests will be needed over time.
These results do not affect how the waste is classified when removed (see risk assessments above).

Classification data and lab results must be uploaded to Street Manager and submitted to Street Works UK every quarter. The Environment Agency will monitor performance. If the risk assessment / lab results correlation is consistently inaccurate, testing frequencies will increase, or worse the use of the protocol may be suspended until improvements are made.