FLORIDA GEOLOGICAL SURVEY


 relatively resistant. Shallow groundwater increases the conductivity
 resulting in reduced signal strength. Subject to the same conditions as
 identified for 2DER testing cited above.

 i. All geophysical investigation reports should include:

 i. Site maps showing locations of all measurements (stations, profile lines,
 traverses soundings or grids) along with all other data collection
 procedures and a discussion of why these locations were selected.

 ii. Specific locations and interpretation of all anomalous areas.

 iii. Uninterpreted raw-data should be included as appendices.

 iv. Identify the limitations of the method, and any problems with data
 acquisition or data processing. Discuss any assumptions made or used as
 a precursor to interpreted results or data processing.

 v. If the results of measurements are processed and interpreted by computer
 (i.e. data is entered into software and a cross section contoured by
 computer) provide other independent data or steps to verify or confirm the
 results.

 j. Because of the three dimensional aspects of sinkholes and other geologic hazards,
 every effort must be taken to ensure that the land surrounding the affected
 structure is adequately investigated, based on an understanding of the local and
 regional hydrogeology.

6. Floor Mapping (often a valuable tool to assist with the determination of structural causes of
observed damage and could yield information corroborating or discounting a sinkhole as the
likely cause)

 a. Used to identify locations where the structure's floor is depressed or
 elevated beyond tolerances allowed by the applicable Florida Building
 Code.

 b. Acceptable methods include (1) transit and stadia rod, (2) manometer, and
 (3) laser level.

 c. A base location that can be reoccupied for subsequent mapping should be
 identified in the report and be as permanent as possible.

 d. Care should be taken to minimize accumulation of error while moving the
 instrument, including use of closed loops or resection of "shot" points
 when utilizing transit or laser level.

 e. Accuracy of the survey measurements should be at least 0.01 foot.