18 Va. Admin. Code § 10-20-382
B. Minimum field and office procedures. The following information must be shown on, or contained in, all plats, maps, or digital geospatial data, including metadata, used to depict the results of the topographic survey:
12. A statement, in the following form, must be shown on or contained in plats, maps, or digital geospatial data, including metadata:
This ________________ (provide description of the project) was completed under the direct and responsible charge of _______________________________ (Name of Professional) from an actual Ground/Conventional RTKGPS (or GNSS) or Remotely Sensed (check all that are applicable) survey made under my supervision; that the imagery or original data was obtained on ______________ (Date); and that this plat, map, or digital geospatial data, including metadata, meets minimum accuracy standards unless otherwise noted.
For the purposes of the certification above, remotely sensed data includes photogrammetry, airborne LIDAR, terrestrial and mobile LIDAR, and for hydrographic surveys, sonar or other acoustic type technologies for measurements.
C. Minimum positional accuracies must be met in accordance with the tables in subdivisions 1, 2, and 3 of this subsection. These tables are not intended to be acceptable in all situations, and the professional will be responsible to perform the work to the appropriate quality and extent that is prudent or warranted under the existing field conditions and circumstances. Metric or other unit of measurements must meet an equivalent positional accuracy. Map or plat scales, or contour intervals, other than those defined in these tables must meet an equivalent positional accuracy. The minimum positional accuracy tables are as follows:
1. Scale and contour interval combinations.
| Map or Plat Scale | Contour Interval |
| 1" = 20' | 1 or 2 feet |
| 1" = 30' | 1 or 2 feet |
| 1" = 40' | 1 or 2 feet |
| 1" = 50' | 1 or 2 feet |
| 1" = 100' | 1 or 2 feet |
| 1" = 200' | 2, 4, or 5 feet |
| 1" = 400' | 4, 5, or 10 feet |
2. Vertical accuracy standards.
| Contours - Vertical Positional Accuracy | Spot Elevations - Vertical Positional Accuracy | |
| Contour line 1' interval | ± 0.60 foot | ± 0.30 foot |
| Contour line 2' interval | ± 1.19 feet | ± 0.60 foot |
| Contour line 4' interval | ± 2.38 feet | ± 1.19 feet |
| Contour line 5' interval | ± 2.98 feet | ± 1.49 feet |
| Contour line 10' interval | ± 5.96 feet | ± 2.98 feet |
| Positional Accuracy is given at the 95% confidence level. |
3. Horizontal accuracy standards.
| Well defined ground points - Horizontal (Radial) Positional Accuracy | ||
| Map or Plat Scale | Absolute Horizontal Positional Accuracy | Relative Horizontal Positional Accuracy |
| 1" = 20' | ± 0.8 foot | ± 0.20 foot |
| 1" = 30' | ± 1.1 feet | ± 0.30 foot |
| 1" = 40' | ± 1.5 feet | ± 0.40 foot |
| 1" = 50' | ± 1.9 feet | ± 0.50 foot |
| 1" = 100' | ± 3.8 feet | ± 1.00 feet |
| 1" = 200' | ± 7.6 feet | ± 2.00 feet |
| 1" = 400' | ± 15.2 feet | ± 4.00 feet |
| Positional Accuracy is given at the 95% confidence level. |
§§ 54.1-201 and 54.1-404 of the Code of Virginia.
Derived from Virginia Register Volume 25, Issue 3, eff. December 1, 2008; amended, Virginia Register Volume 32, Issue 6, eff. January 1, 2016; Volume 37, Issue 24, eff. September 2, 2021; Volume 42, Issue 16, eff. May 1, 2026.