Policy for the Collection and Archiving of Electronically 
Recorded Data

In Reply Refer To: WGS-Mail Stop 460 SEP 18, 1987


Subject:        PROGRAMS AND PLANS--Policy for the Collection and 
Archiving of Electronically Recorded Data

The purpose of this memorandum is to state the Water Resources 
Division (WRD) policy regarding the collection and archiving of 
electronically recorded data.  WRD policy permits the collection 
and storage of hydrologic data utilizing electronic devices such 
as satellite telemetry or magnetic recording devices located at 
the data-collection stations. Electronically recorded data can 
be utilized to generate records for publication, interpretive 
studies, research, and original data archives, provided that the 
data are handled in accordance with the updated policy 
guidelines presented in the attachment.  (The guidelines were 
originally issued with WRD Memorandum No. 84.106, subject as 

Adherence to the policy guidelines will also sustain the legal 
status of electronically recorded data.  The Associate 
Solicitor, Energy and Resources, in a memorandum to the 
Director, Geological Survey, dated June 10, 1983, concluded that 
"Data originally prepared as microfilm or recorded directly into 
a magnetic tape, and processed through a computer to produce the 
first hard copy is properly admissible and will constitute valid 
evidence in a court proceeding."

The guidelines in the attachment provide for the verification, 
transfer, transport, processing, and archiving of original data 
recorded on volatile or reusable media, such as magnetic disks 
and tapes, computer chips, or other solid-state memory devices.  
All personnel responsible for the collection, analysis, 
manipulation, and storage of data using these technologies 
should assure that the specified requirements are implemented.

The guidelines require the archiving of original data, but do 
not describe the content, format, or procedures to be used.  The 
Office of Surface Water will begin to develop these procedures 
in fiscal year 1988 as a part of a cooperative effort with the 
Southeastern Region and the Office of the Assistant Chief 
Hydrologist for Scientific Information Management.  Additional 
information in this regard will be furnished as soon as it 
becomes available.

Chief Hydrologist


WRD Distribution:       A, B, S, FO, P0


The Water Resources Division (WRD) at present collects 
hydrologic data at a number of sites where there is no hard-copy 
archivable record of the basic sensor information generated at 
the site.  The two types of sites are: (1)  locations where the 
data are transmitted from a remote location by land line or 
radio (satellite or land based) telemetry to a central location 
where data are recorded on a medium such as magnetic tape, disk, 
or solid-state memory device; and (2) locations where data are 
recorded at a remote location on a medium such as magnetic tape, 
disk, or solid-state memory device.  It is anticipated that 
significant increases in this type of data collection and 
recording will occur in the next decade.

The purpose of this document is to establish policy guidelines 
for the collection and archiving of data which are recorded on 
electronic media. These guidelines follow:

1.  Data verification.--Sensors will be read or checked 
independently of the recording system as appropriate or by using 
the recommended data-record verification procedure during field 
visits.  Readings or verification information will be written or 
coded on a log with time and date and compared with the system 
readings as appropriate via some form of mandatory system 
output, such as a digital display.  Written or electronic logs 
and calibration tests will be checked against data listings 
produced from the storage medium during office data reduction 
and will become part of the permanent record.

2.  Data transfer. --The transfer of data from one electronic 
storage medium to another as a result of remote telemetry, 
onsite transfer (recorder to portable field unit), or office 
transfers to a computer will require thorough and, where 
possible, automated checking to ensure that the transfer was 
successful, or that as much data as possible have been recovered 
and errors identified.

3.  Data transport.--The unstable nature of the medium 
necessitates the establishment and use of special procedures and 
equipment to prevent data errors or loss.  Storage media, such 
as portable field computers, should be carried in protective 
containers from the field site to the office to protect the 
media from physical damage.  Storage locations in field vehicles 
should be constructed and located so as to prevent physical 
damage and electromagnetic destruction of stored data.

4.  Data processing.--The initial data processing in the office 
will be for the purpose of obtaining an archivable copy of the 
original data as explained in item 5.  For this reason, the data 
are not to be manipulated by the field instrument or by a 
computer except for the purpose of converting recorded signals 
into data having commonly used units for hydrologic use or for 
the purpose of displaying the data in a convenient format.  If 
data compaction schemes have been used, a key or other 
information must be supplied for reading the data.  Where 
"intelligent" sampling schemes are used in the collection of 
data, the scheme and criteria for the "intelligent" sampling 
must be documented.

5.  Data archival.--It is the policy of the WRD, as stated in 
WRD Memorandum No. 77.83 dated March 30, 1977, to indefinitely 
maintain and preserve all geologic and hydrologic raw-data 
records in their original form.  In the case of electronically 
recorded data, a copy will be preserved on a nonvolatile medium 
such as paper or microfilm.

Archivable paper copies can be obtained as computer printout of 
the raw data (unprocessed except as stipulated in consideration 
4).  An archivable copy of the data may also be obtained by 
computer output microfilm (COM) of the raw data.  Silver halide 
based film is to be used for this purpose. Thorough checks must 
be made to ensure that the computer printout copy is consistent 
with the field recorded data.

Paper or microfilm copies of data to be used for permanent 
storage must be identified by station identification numbers or 
other identifier, station name, and the period of record.  Also, 
type of data recorded such as stage, rainfall, or specific 
conductivity must be clearly noted as well as other appropriate 
information which identifies the data.  The storage of paper or 
microfilm records will be in accordance with the WRD Records 
Disposition Schedule which is the WRD policy on the handling and 
storage of data records.  Following the creation of an 
archivable copy of the original data, updates may be made to 
account for known sensor, recorder, or telemetry malfunctions.

6.  Reuse of electronic storage medium.--The field and transport 
medium used for storing sensor information will generally be 
erased and reused at some time.  These temporarily stored data 
are not to be erased until an archivable copy of the data has 
been obtained and checked for accuracy.  The storage medium for 
the field unit (onsite data collection and storage device) shall 
contain sufficient memory for storage of new data so as to allow 
time for data transport and the creation of an archivable copy 
before the retrieved data are overwritten in the field unit.