British Standards Institution PAS 128, Specification for underground utility detection, verification and location is the new publicly available specification document which allows the utility survey industry to deliver its services to a recognised level of accuracy. Although it is aimed at the survey practitioner, we understand that our clients need a know how to specify a PAS 128 survey.
Expected that with time, education, and experience by applying PAS128 standard, this will lead to more effective planning and safer execution of street works, civil works, ground works, and utility-based activities.
Safedigging Surveys provides you with a utility identification service for all your project requirements, from obtaining Utility record information, to liaising with clients and site personnel we can deliver a friendly professional personal service for all our clients.
This includes client consultation, time allowed for fieldwork/reporting, and submission of deliverables.
This covers survey types, quality levels, and the project team.
Focuses on site-specific and safe system of work.
Should be obtained before fieldwork begins.
Evaluates the quality of existing mapping and/or the need for a new topographical survey.
Conducted post fieldwork to review survey results.
PAS 128: 2022 represents the current standard for underground utility detection, aiming to define the precision with which survey data must be collected.
This standard emphasizes the expected quality and reliability of data. It is beneficial to specify a PAS 128 survey for clients, practitioners, and the public.
Key aspects of the specification include:
PAS 128 ensures a comprehensive approach for conducting high-quality utility surveys across the UK. It defines four quality levels for surveys, labeled A to D, each specifying the precision required for PAS 128 compliance. Additionally, the survey area may be divided, allowing different survey levels to be applied to various sections of the site.
This segmentation enables survey providers, to tailor surveys that not only meet budgetary constraints but also adhere to compliance standards.
The accompanying table outlines the scope of each survey type and the associated cost benefits.
| Quality Level | Scope upon which results are based | Relative accuracy obtained | Relative confidence level in results | Relative cost |
|---|---|---|---|---|
| D | Desktop utility records search | Lowest | Lowest | Lowest |
| C | Site Reconnaissance | Medium Low | Medium Low | Medium Low |
| B | Detection With EML and GPR | Medium High | Medium High | Medium High |
| A | Verification Using Intrusive Inspection | Highest | Highest | Highest |
| Quality Level | Relative accuracy obtained | Relative confidence level in results | Relative cost |
|---|---|---|---|
| D | Lowest | Lowest | Lowest |
| C | Medium Low | Medium Low | Medium Low |
| B | Medium High | Medium High | Medium High |
| A | Highest | Highest | Highest |
| Survey Type | EML | GPR General | GPR Post Processing | Other Techniques | Quality Level Achievable | Typical Application |
|---|---|---|---|---|---|---|
| M1 M1P | 10M Intervals 5m Tracing A Utility | As Applicable | No/Yes | 5M Survey Grid | B1 B2 B3 B4 B1P B2P B3P | Undeveloped Area |
| M2 M2P | 5M Intervals 2M Tracing A Utility | 2M Orthogonal Or High Density | No/Yes | 2M Survey Grid | B1 B2 B3 B4 B1P B2P B3P | Suburban Area Or Similar |
| M3 M3P | 2M Interval s 1M Tracing A Utility | 1M Orthogonal Or High Density | No/Yes | 1M Survey Grid | B1 B2 B3 B4 B1P B2P B3P | Busy Urban Area Or Similar |
| M4 M4P | 2m Intervals 0.5M Tracing A Utility | 0.5M Orthogonal Or High Density | No/Yes | 0.5M Survey Grid | B1 B2 B3 B4 B1P B2P B3P | Congested City Area |
PAS128 is crucial for enhancing the safety and efficiency of various projects involving underground utilities. In street works, it helps in accurate utility mapping, reducing the risk of accidental strikes and service disruptions. Civil projects benefit from reduced risk and cost, as precise utility locations prevent unexpected issues during excavation. For utility works, PAS 128 ensures that new installations and maintenance activities are based on reliable and detailed utility data, fostering smoother project execution and better resource management.
