Estimation of leakage between the shallow and principal aquifers in the Las Vegas Valley Water District's main well field, Las Vegas, Nevada

Under natural conditions in Las Vegas Valley the shallow aquifer was recharged by upward leakage of ground water from the principal aquifer. Presently recharge to the shallow aquifer is infiltration from over-irrigation which poses a potential threat to the quality of the principal aquifer. To evaluate this contamination potential, water levels from monitoring wells in both aquifers were collected, a three dimensional finite difference ground-water flow model (MODFLOW) was developed to estimate volume and velocity of potential leakage, and water quality samples were collected; Water levels collected in the shallow aquifer show a dependency on potentiometric head in the principal aquifer. A linear regression analyses showed good correlation of water level changes in the shallow aquifer due to injection and pumping operations in the principal aquifer with increasing correlation coefficients with shallow aquifer depth; These analyses indicate that within the District's main well field, the primary source of shallow aquifer ground water is the principal aquifer and that potential contamination from the upper poorer quality ground water (due to evapotranspiration) is not a present threat due to very slow vertical leakage. (Abstract shortened by UMI.).

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Geoscience

Grantor dc:publisher

University of Nevada, Las Vegas

Year

1993

Author dc:creator

• Bernholtz, Alan Joseph

Statement dc:rights

• IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

English

Identifier

https://oasis.library.unlv.edu/rtds/317

OAI identifier oai:identifier

oai:oasis.library.unlv.edu:rtds-1316