LOCATE COMPLIANCE FAQ
Do pipeline operators require GPS locate records? Some do, in their own contractor requirements. There's no national rule. PHMSA's April 2026 advisory bulletin on excavation damage (ADB-2026-05) asks pipeline operators to build CGA Best Practice 4-11, Accuracy of Locating, into their procedures and to audit locator performance. The pipeline safety reauthorization bill the Senate passed in April 2026 (S. 2975, Sec. 211) lists white-lining, positive response before excavation and newly installed facilities being locatable among the one-call practices it wants states to adopt. It isn't law yet. Colorado has required new underground facilities to be electronically locatable when installed since 1 January 2020 (SB 18-167). None of these sets a format for locate records. They point the same way.
Are GPS locate records required by law? One-call laws generally require lines to be located and marked before digging. We're not aware of one that sets a format for a GPS locate record, but requirements vary by state, so check yours. We provide records, not legal advice. The PHMSA bulletin, the Senate bill and state programs like Colorado's all point toward better locate records. Companies that set up structured records now do it on their own schedule.
What should a locate record contain? Six groups of information, captured while the locate happens: - Position of each point, with the GNSS fix type, correction source and accuracy at capture - Depth, read from the locator, and the locate method, frequency and signal strength - Utility type and subtype, with material and size where known, and the ticket number - The locator, and a timestamp per measurement - A sketch drawn to scale, and photos tied to where they were taken - The record's history: what was captured, when it synced, and whether anything changed
We'll send the full field list on request.
What's the difference between a closed ticket and a locate record? A closed ticket shows a locate was requested and completed. A locate record shows what the locator did: where each point was found, the depth the locator read, the method, who did it and when, and how accurate the position was. The first is an assertion. The second is a record someone else can check. TerraFlow records the locate. It doesn't prove it.
How accurate does GPS need to be for a locate? Tolerance zones are set by state law, commonly 18 inches (46 cm) either side of the mark and wider in some states (PHMSA state law summaries). GPS.gov puts a phone's GPS at about 16 feet (4.9 m) under open sky, and it's worse under trees (GPS.gov). SBAS corrections such as WAAS typically bring that to 3 to 7 feet (1 to 2 m) (FAA WAAS performance reports). RTK receivers are specified by their manufacturers at around 1 to 3 cm (about half an inch to an inch and a quarter); check the specification for your model. If the position error is bigger than the tolerance zone, the record can't show which side of the zone the line was on. That's why RTK matters for locates.
Does TerraFlow record the GPS accuracy? Yes, on every point: the fix type (RTK fixed, float, DGPS or autonomous), the correction source, and the horizontal and vertical accuracy the receiver reported at that moment. The record never claims more precision than the hardware delivered.
How does a locate relate to ASCE 38-22? ASCE 38-22 is the subsurface utility engineering standard. It places surface geophysics, including electromagnetic locating, at Quality Level B, with the interpreted position tied to the project survey datum to 0.2 ft (60 mm) horizontally (ASCE/UESI/CI 38-22). An RTK receiver is specified by its manufacturer well inside that. Whether a particular job is a QL-B deliverable depends on the survey method and the engineer responsible, not the software.
Can records be in feet and inches? Yes. Exports come out in feet and inches or metric. The on-screen accuracy readout stays in centimetres, because at RTK it's the only unit small enough to show how good the number is.
Does it work without cell signal? Yes. TerraFlow Mobile works offline first. Maps, forms and data stay on the device, and the locate syncs to the office as soon as there's signal.
How long does it take to train a crew? About an hour. We set up your asset types, attributes and sketch conventions first, and the help centre has every step written down, including setup for each supported device.
Can TerraFlow run inside our own network? Yes. TerraFlow Enterprise is the on-premises edition: application, database and field sync on your own servers. You don't need a policy reason to choose it. Details.
Is anyone already capturing locates with RTK and TerraFlow? Yes. PUC Services in Sault Ste. Marie deployed TerraFlow to connect its crews' RTK receivers to ArcGIS Online. Esri Canada reports PUC's positioning error fell from 10 to 16 feet (3 to 5 m) to about an inch (2.54 cm) (Esri Canada, March 2026). Premier Locates uses it to map locates straight to CAD.
Does TerraFlow replace our ticket system? No. Tickets keep arriving through your one-call centre and your ticket system, the way they do now. TerraFlow adds the locate record the ticket was never built to hold, and Data Engine delivers it in the format you or your operator asks for.
How do locate records reach the operator? Often they don't. Many operators see only a completion status in the one-call system. With TerraFlow, the record syncs to Data Engine and goes to the operator in the format they asked for: their GIS, their asset system or a file.
What is vendor-neutral locate software? Software that reads locators and GNSS receivers from more than one manufacturer and produces the same record whichever is connected. It's also worth asking who owns the software vendor. Ask whose customers their roadmap is built for.
Who owns the locate records? Not TerraFlow. We don't own the records captured in our software. How contractors and operators share them is between them.
