Defining wetlands is not a simple task, for there is no one definition. The following was taken from Mitsch and Gosselink (2000) and provides a good starting point for understanding the complexity of wetlands.

Three main components often included in the definition of a wetland:

1. Wetlands are distinguished by the presence of water, either at the surface or within the root zone.
2. Wetlands often have unique soil conditions that differ from adjacent uplands.
3. Wetlands support vegetation adapted to the wet conditions and, conversely, are characterized by an absence of flooding-intolerant vegetation.

Difficulty in defining wetlands:

1. The boundaries of wetlands cannot always be determined by the presence of wetlands at any one time.
2. Wetland species range from those that have adapted to live in either wet or dry conditions to those adapted to only a wet environment.
3. Wetlands vary widely in size.
4. Wetland location can vary greatly. Wetland types include coastal slat marshes, inland pothole marshes, and forested bottomland hardwoods.

For ecological studies and inventories, the 1979 U.S. Fish and Wildlife Services definition has been and should continue to be applied to wetlands in the United States.

Wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water Wetlands must have one or more of the following three attributes: (1) at least periodically, the land supports predominantly hydrophytes: (2) the substrate is predominantly undrained hydric soil: and (3) the substrate is nonsoil and is saturated with water or covered by shallow water at some time during the growing season of each year. (Classification of Wetlands and Deepwater Habitats of the United States. Cowardin et al., 1979)

When wetland management, particularly regulation, is necessary, the U.S. Army Corps of Engineers' definition, as modified, is probably most appropriate.

The term "wetlands" means those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. (33 CFR 328.3(b); 1984)

Since 1989, the term jurisdictional wetland has been used for legally defined wetlands in the United States to delineate those areas that are under the jurisdiction of Section 404 of the Clean Water Act or the swampbuster provision of the Food Security Act.

The term "wetland" except when such term is part of the term "converted wetland" means land that-
(A) has a predominance of hydric soils:
(B) is inundated or saturated by surface or ground water at a frequency and duration sufficient to support a prevalence of hydrophytic vegetation typically adapted for life in saturated soil conditions; and
(C) under normal conditions does support a prevalence of such vegetation.

As you can see, defining wetlands is not an easy task. Most federal, as well as state, agencies follow different definitions for wetlands. Economics and politics typically play a large part in deciding whether or not an area is a wetland, and if so, what can be done to it legally.
Perhaps we should shift our focus now to the role they played in the fiasco that was to be the Boyd County LLRW facility. The entire application, licensing, and legal processes surrounding the facility are full of references to wetlands. Early on it seemed that wetlands were to be avoided. Wetlands were claimed to be the main reason the application for a license was denied. Let's progress through the major reports and papers and highlight the role wetlands played.
The final report of the "Site Selection Process" included several criteria specifically regarding wetlands. For example, the "County Level Screening Considerations" included a section on surface water, which established criteria "CC-2 Away from water bodies (lakes, rivers, creeks, canals & ponds) and wetlands." The "Identification of Potential Sites Considerations" also had a surface water section with 2 criteria: "PC-1 Proximity to water bodies (lakes, rivers, creeks, canals & ponds) and wetlands" and "PC-2 Areas with drainage problems (e.g. local ponding)." The "Comparison of Potential Sites Considerations" repeated criteria PC-1, calling it EC-2. These criteria may be why the original 320 acre site was reduced to 110 acres to avoid wetlands in the site design. However, a small one acre wetland still existed within the smaller site but not within the footprint of the facility.
The GAO Report to Senator Exon revealed some interesting things about the site selection process. In the "Boyd County Site" section is states:
Us Ecology's studies of the area around the Boyd County site found that a flood from the stream on the property could reach the facility. The contractor's computer modeling showed that wetlands on the property could receive groundwater as well as surface drainage in wet years.

Also of concern was the fact that "the geologic and hydrologic data were collected during a dry year," an issue that became very relevant at trial.
The denial of the application does not specifically mention wetlands but states the "Site lacks sufficient depth to water table," based on hydrographs provided by US Ecology, Inc. (USE), concluding that "The disposal facility will be constructed below the water table in some places, thereby providing no depth." In fact, a draft safety evaluation report (DSER) stated that "in very wet years, the water table may remain very near the surface." Also included in the reasoning for denial was that "Local residents familiar with the site stated that they had observed ponded surface water, seeps, and saturated ground depression at the site." These factors would qualify the area as having wetlands.
The trial and final court decision by Judge Richard Kopf did involve discussion of wetlands, but they were not a focus. During the trial "Nebraska agues that USE eventually conceded that groundwater did at times discharge wetlands W-1 and possibly W-2," however proof from either side was not offered. Here is an excerpt from the decision in which the judge describes his opinion of the wetlands in question:
From my point of view, it is misleading to call these areas "wetlands." Idyllic havens for wildlife they were not. They are muddy water holes of the kind frequently seen being used by cattle in the many pastures that dot the high plains. In very dry years the wetlands hold no water. In very wet years the wetlands hold water sufficient to float a small row boat.

Again, these factors would qualify "these areas" as wetlands.
The review manager for site characteristics and lead geologist for the Central Interstate Compact, Marvin Carlson, concluded that groundwater was a problem based on hydrographs submitted by USE late in the game. These graphs were based on the "wet years" of 1995-1997 and demonstrated a high water table which is different than those based on previous dry years. As mentioned previously, wetlands do not necessarily hold water constantly and when water is present it can be for very brief periods. These late hydrographs were a point of dispute in the court decision. The following section of this report will discuss a differing view as well as the "water pathways" of the site location. These pathways can include Ponca Creek and wetlands.
The laws regarding LLRW and the role and/or limits of water pertaining to it are very clear. Nebraska Code Title 194 contains several sections that are specific to ground and surface water. They are as follows:
Title 194, Chapter 5, Section 001.01E: The disposal site shall be generally well drained and free of areas of flooding or frequent ponding. Waste disposal shall not take place in a 100-year flood plain or wetland as defined in Executive Order 11988, "Floodplain Management Guidelines."

Title 194, Ch. 5, Section 001.01G: The disposal site shall provide sufficient depth to the water table that ground water intrusion, perennial or otherwise, into the waste will not occur. In no case will disposal be permitted in the zone of fluctuation of the water table.

Title 194, Ch. 5, Sections 001.01H: The hydrologic unit used for disposal shall not discharge ground water to the surface within the disposal or management sites.

All three of these sections were shown to be violated. However, it is easy to see how the issue of wetlands can be such a difficult one to settle.

Glossary of terms (as defined by the Penguin Dictionary of Geography)