Underground Services Survey Specification
To carry out a PAS 128 compliant utility (buried services) survey and present all relevant information.
Survey will be combined with our topographical survey for context. If records are not already available for this site, we recommend instructing us to carry out a Desktop Utility Search as a required prerequisite to meet PAS 128 standards. PAS 128 Quality Levels Explained
SolidPoint delivers utility surveys categorized by the British Standard PAS 128 framework, allowing you to select the appropriate level of depth, detection, and verification for your project:
Type D (Quality Level D / QL-D) — Desktop Utility Search:
Compilation and review of statutory and private utility records. Can be supplied by the client or instructed via SolidPoint (£300–£500 extra, allowing up to 15 working days). Type C (Quality Level C / QL-C) — Site Reconnaissance:
Correlating desktop records with visible surface features (inspection chambers, valve covers, utility markers, and service cabinets) on site. Type B (Quality Level B / QL-B) — Detection Survey:
Non-invasive subsurface detection using Electromagnetic Locating (EML) and Ground Penetrating Radar (GPR) across the site to map utility positions and depths. Type A (Quality Level A / QL-A) — Verification:
Precise physical exposure and 3D verification of utilities via trial pitting or vacuum excavation (available as a specialist extra for critical design clashes). General Notes & Technical Tolerances
Positions & Depths: Vertical position (depth) is indicative to the top of the utility feature, recorded as DTS (depth to top of service), and should not be taken as exact. Horizontal position is indicative to the center of the utility feature. Assumed Routes & Drainage: Where logic dictates a utility exists but cannot be positively confirmed with technology, an ASR (assumed route) is recorded. Sewer and manhole details are obtained from surface observation and measurement. Where precise details are critical, our engineers can use a sonde to trace pipelines; chamber entry requiring confined space qualification is available at extra cost. Paint Markings: Permanent paints are used to mark utility positions. Due to ground, weather, and traffic conditions, no guarantee is given for their durability, and drawings remain the primary reference. Non-Invasive Limitations: Utilities are detected using non-invasive technologies whose performance can be affected by ground and weather conditions. While our engineers use reasonable endeavors, 100% detection cannot be guaranteed, and unrecorded services may remain. Safety First: Irrespective of survey data or statutory plans, excavation work must be undertaken with extreme caution and in accordance with HSE Guidelines HSG47 (Avoiding Danger from Underground Services). Services We Include in Our Survey
Metallic gas mains ($\ge 38\text{mm}$ diameter) Metallic water mains ($\ge 38\text{mm}$ diameter) Electricity supply cables ($440\text{V}$ to $66\text{kV}$ live) Electric cables to street lighting Drainage runs ($\ge 100\text{mm}$ diameter) where pipe access is possible Telephone, communications, and computer cables Empty ducts ($\ge 100\text{mm}$) Underground heating pipes Other metallic services capable of transmitting a signal Depths of all services where possible Services We Exclude from Our Survey
Non-metallic gas mains ($\le 38\text{mm}$ diameter) Non-metallic water mains ($\le 38\text{mm}$ diameter) Tracing drains or ducts without access for a drain sonde Service connections (unless specifically requested with property access arranged) Man entry into confined spaces (unless specifically requested) CCTV condition surveys (quoted separately) Manhole covers that cannot be lifted after 20 minutes of levering with hand tools Working in unsafe or impractical areas Internal services (unless requested) Ground Penetrating Radar (GPR)
GPR uses radar pulses to image the subsurface. While standard electromagnetic techniques locate conductive metallic pipes and cables, GPR targets non-conductive materials (such as plastic or concrete) where ground conditions permit.
Items that may be locatable with GPR:
Underground storage tanks Desktop Utility Search
If records are not already available, we recommend instructing us to carry out a Desktop Utility Search. Please note that utility providers may take up to 15 working days to forward their records.
