3.1. LWDB structure
Six database files with data pertinent to the
use of North American wetlands for treatment of
high strength livestock wastewaters were developed
(CH2M HILL and Payne Engineering,
1997). LWDB files were given names reflective of
their contents (within the eight-letter DOS limitation):
sites, systems, cells, operate, literat and
people. Separate database files were developed
because of the hierarchical nature of the data
(i.e. one site may have several systems, and one
system may have multiple cells). Separate files
obviate the need for repetitive (overlapping)
data.
The sites file ties basic information about each
site, such as site name, state, community, and
EPA region, to its particular site number.
Unique numbers were assigned to wetland sites
for this project. The inherent value of any particular
number is meaningless; its purpose is to
ensure that information about each site remains
distinct throughout the tables and that these various
database files can be cross-referenced. There
are 65 fields containing 239 characters in this file.
The ‘checkoff’ fields are the smallest, with a
width of one character. Checkoff fields contain
an ‘X’ to indicate that information for a particular
parameter exists in the six files.