Data Series 190
U.S. GEOLOGICAL SURVEY
Data Series 190
Table 4. Description of general- and detailed-condition attributes assigned to water levels in Rainier Mesa area, Nevada Test Site, Nye County, Nevada.
[Number of water levels: Number of water levels in Rainier Mesa assigned with this attribute. Each water level was assigned only one general-condition attribute but may have multiple detailed-condition attributes]
Attribute name | Description | Number of water levels |
---|---|---|
General-condition attribute | ||
Localized conditions | Water level represents localized, typically transient, hydrologic conditions in aquifer (for example, nuclear-test effect or localized pumping). | 4 |
None | Well is dry or obstructed or site was visited but water level was not measured. | 3 |
Nonstatic level | Water level is affected by activities in the well such as aquifer testing, well construction, or pumping; water level does not represent conditions within the aquifer. | 679 |
Steady state–LOCAL | Water level approximates predevelopment, steady-state, hydrologic conditions in a well that monitors a local-scale flow system, such as a perched aquifer. Water level is considered to be steady state relative to long-term (50–100 years) climatic conditions. Water-level changes occurring as a result of natural conditions are considered steady state for the purposes of this analysis. | 39 |
Steady state–REGIONAL | Water level approximates predevelopment, steady-state hydrologic conditions in a well that monitors the regional ground-water flow system. The regional flow system is defined as the fully saturated part of the flow system. Water level is considered to be steady state relative to long-term (50–100 years) climatic conditions. Water-level changes occurring as a result of natural conditions are considered steady state for the purposes of this analysis. | 189 |
Suspect | Water level is suspect or in error, and cannot be attributed to any known hydrologic cause. | 277 |
Transient–LOCAL | Water level represents changes from pumping in a local-scale flow system, such as a perched aquifer. | 27 |
Transient–REGIONAL | Water level represents changes from pumping in the regional ground-water flow system. The regional flow system is defined as the fully saturated part of the flow system. | 9 |
Detailed-condition attribute | ||
Abrupt change | Water level rapidly shifted or changed from previous measurements. | 31 |
Anomalous–high | Water-level altitude is unusually high relative to other measurements at the site or at nearby sites. | 2 |
Anomalous–low | Water-level altitude is unusually low relative to other measurements at the site or at nearby sites. | 1 |
Consistent | Water level appears to be part of a reasonably consistent trend representative of general water-level conditions in the area. | 176 |
Declining trend | Water level appears to be part of a discernable, overall downward trend. Possible causes include nearby pumping, decreased recharge, equilibration following drilling, or depressurization after a nuclear test. | 329 |
Dry | Site was dry at time of measurement. | 1 |
Elevated | Water level is elevated appreciably above the regional ground-water system, probably because of natural conditions. | 733 |
Equilibration | Water level appears to be part of a discernible, overall trend that is approaching an equilibrium level, either higher or lower than the initial measurement. Equilibration commonly occurs following well construction, pumping, or nearby nuclear testing. | 698 |
Erratic/unstable | Water level is erratic and unstable. | 40 |
Injection/recovery | Water level appears to be affected by recent injection of water, mud, or other fluid into the well or hole. | 182 |
Limited data | Water level is one of a limited number. Therefore, general-condition attribute assigned to water level is tentative. | 30 |
Maximum estimate | Water level or depth to bottom of well (where well is dry) represents a maximum estimate of the equilibrated water-level altitude in the monitored hydrologic unit. | 9 |
Minimum estimate | Water level represents a minimum estimate of the equilibrated water-level altitude in the monitored hydrologic unit. | 3 |
Obstruction | Water-level measurement was attempted but could not be made because of an obstruction in the hole. | 2 |
Packer test | Water level was measured during a packer test. | 319 |
Pumping/recovery | Water level appears to be responding to current or past pumping at the site or at a nearby site. If water-level measurement is missing, well was pumping at time of measurement. | 184 |
Questionable accuracy | Water level may be inaccurate because of poor measurement. | 48 |
Rising trend | Water level appears to be part of a discernible, overall rising trend. Possible causes include a decrease in nearby pumping, equilibration following drilling, and above-normal precipitation. | 602 |
Suspected perched water | Water level appears to represent perched-water conditions. | 580 |
Suspected unsaturated | Water level is suspected to represent remnant fluid in well. Hole is believed to be unsaturated. | 19 |
Testing area | Site located within 1 mile of one or more underground nuclear tests. Water level possibly is affected. | 467 |
Tunnel effect | Water level may be affected by nearby tunneling. | 223 |
Uncertain | General-condition attribute assigned to water level is tentative because of uncertainty in interpreting water level or hydrograph. | 134 |
Undeveloped | Water level may not accurately represent hydrologic conditions because of insufficient or no well development. | 138 |
Well-construction effect | Water level appears to be equilibrating from, or is suspected of being affected by, prior well-construction and(or) development activities. | 156 |