Hydrogeochemistry of stream channel recharge of sewage effluent, northwest of Tucson, Arizona

Persistent Link:
http://hdl.handle.net/10150/191176
Title:
Hydrogeochemistry of stream channel recharge of sewage effluent, northwest of Tucson, Arizona
Author:
Esposito, David M.
Issue Date:
1993
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
This investigation has documented the water quality impacts of stream channel recharge of sewage effluent northwest of Tucson and has evaluated the hydrogeochemical mechanisms potentially responsible for observed water quality changes. The evaluation was accomplished partly through construction of twelve monitor wells and implementation of a quarterly water quality monitoring program for surface water and groundwater. Constituents monitored included major inorganic chemical constituents, trace inorganics, trace metals, priority pollutants/trace organics and microbiological contaminants. ¹⁵N also proved useful in the study. The significance of a reducing zone immediately beneath the bed of the Santa Cruz River with respect to denitrification was documented. Findings of this investigation indicate that while sewage effluent is of poor quality with respect to drinking water standards, groundwater recharged by sewage effluent is of improved quality. Other findings include: * Nitrate in shallow groundwater near the Santa Cruz River in the Cortaro area appears to be primarily from stream channel recharge of sewage effluent; * Nitrate-N contents of effluent recharged groundwater averaged about 5 mg/1, well below the maximum contaminant level for drinking water of 10 mg/1, representing a 75 percent loss in total nitrogen during stream channel recharge of sewage effluent (assuming no mixing); * Both stream channel recharge of sewage effluent and agricultural deep percolation contribute to nitrate in shallow groundwater near the Santa Cruz River in the Marana area; * The reducing zone beneath the Santa Cruz River may be responsible for denitrification losses of up to 5 mg/1 of nitrate-N. This would explain approximately 30 percent of nitrogen losses, on average, between effluent and recharged groundwater; * The mechanisms of cation exchange and mixing with groundwater from other sources can explain the major changes in water quality between effluent and groundwater with respect to major inorganic chemical constituents; * Renovation of effluent with respect to coliform bacteria and enteric viruses content during recharge is not complete.
Type:
Dissertation-Reproduction (electronic); text
Keywords:
Hydrology.; Water quality -- Arizona -- Tucson Region.; Sewage disposal in rivers, lakes, etc. -- Arizona -- Tucson Region.
Degree Name:
Ph. D.
Degree Level:
doctoral
Degree Program:
Geosciences; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Titley, Spencer R.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleHydrogeochemistry of stream channel recharge of sewage effluent, northwest of Tucson, Arizonaen_US
dc.creatorEsposito, David M.en_US
dc.contributor.authorEsposito, David M.en_US
dc.date.issued1993en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThis investigation has documented the water quality impacts of stream channel recharge of sewage effluent northwest of Tucson and has evaluated the hydrogeochemical mechanisms potentially responsible for observed water quality changes. The evaluation was accomplished partly through construction of twelve monitor wells and implementation of a quarterly water quality monitoring program for surface water and groundwater. Constituents monitored included major inorganic chemical constituents, trace inorganics, trace metals, priority pollutants/trace organics and microbiological contaminants. ¹⁵N also proved useful in the study. The significance of a reducing zone immediately beneath the bed of the Santa Cruz River with respect to denitrification was documented. Findings of this investigation indicate that while sewage effluent is of poor quality with respect to drinking water standards, groundwater recharged by sewage effluent is of improved quality. Other findings include: * Nitrate in shallow groundwater near the Santa Cruz River in the Cortaro area appears to be primarily from stream channel recharge of sewage effluent; * Nitrate-N contents of effluent recharged groundwater averaged about 5 mg/1, well below the maximum contaminant level for drinking water of 10 mg/1, representing a 75 percent loss in total nitrogen during stream channel recharge of sewage effluent (assuming no mixing); * Both stream channel recharge of sewage effluent and agricultural deep percolation contribute to nitrate in shallow groundwater near the Santa Cruz River in the Marana area; * The reducing zone beneath the Santa Cruz River may be responsible for denitrification losses of up to 5 mg/1 of nitrate-N. This would explain approximately 30 percent of nitrogen losses, on average, between effluent and recharged groundwater; * The mechanisms of cation exchange and mixing with groundwater from other sources can explain the major changes in water quality between effluent and groundwater with respect to major inorganic chemical constituents; * Renovation of effluent with respect to coliform bacteria and enteric viruses content during recharge is not complete.en_US
dc.description.notehydrology collectionen_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.typetexten_US
dc.subjectHydrology.en_US
dc.subjectWater quality -- Arizona -- Tucson Region.en_US
dc.subjectSewage disposal in rivers, lakes, etc. -- Arizona -- Tucson Region.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGeosciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairTitley, Spencer R.en_US
dc.identifier.oclc212628412en_US
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