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CHAPTER IV PROBLEM IDENTIFICATION AND QUANTIFICATION ACTIVITIES o l\J .:::. w flow of the river immediately below the dome was approximately 582 cfs; and the average TDS concentration was 334 mg/L, representing an annual salt loading of 191,600 tons. The difference between the 191,600 tons and the 118,900 tons--72,700 tons per year--represents the loading to the river by all sources in the vicinity of the dome. An annual salt loading of 51,300 tons annually was attributed to Coal and Curtis Creeks, based on gaging stations and water quality samples at these two sources. The remaining salt loading was assumed to be derived from the dome itself. Based on an average water quality of 16,690 mg/L, the discharge from the dome was estimated to be about 1.3 cfs. '; Hypotheses Two basic hypotheses were studied which, it is believed, account for saline water escaping from deep saline aquifers (the Entrada and the Weber Formations) and flowing to the surface along the north side of the White River. One concept was that deep exploratory wells provided the corridors for saline water under pressure in deep aquifers to escape to the surface formations (the Dakota and Morrison Formations) and to flow by gravity to the river; this concept is referred to as the "well- related" hypothesis. Opposite this was the hypothesis that the pressure in the lower saline aquifers forced saline water to the surface along natural fractures in the domal structure. This is referred to as the "natural causes" hypothesis. To some degree, both mechanisms could occur in combination. Based on available data, the "well-related" hypothesis was theo- rized to be responsible for the transmission of saline waters into the White River. Although earlier investigations had centered on the Meeker Well, the Marland Well was believed to actually be the main channel for the saline water movement from the deeper aquifers. According to this hypothesis, the insufficient plug and deteri- orated casing in the Marland Well allowed saline water to move ver- tically into near surface aquifer(s) in the Morrison Formation. The saline water apparently moved laterally by gravity flow along the Morrison and Dakota Formations and surfaced in springs and seeps where the Dakota is exposed by the river. The sequence of events that are believed to have resulted in saline water flowing from the Morrison Formation into the river are described below and depicted in Figure 2. 1. The Meeker Well, drilled in the early 1900' s into the upper Entrada, developed a surface flow of saline water of about 3 cfs. 2. The Ma rland about 1925. the Entrada Well was drilled into the Weber Formation Water moved up the bore from the Weber into Formation, increasing salinity and pressure 12