Gas transport below artificial recharge ponds: Insights from dissolved noble gases and a dual gas (SF6 and 3He) tracer experiment

Jordan F. Clark*, G. Bryant Hudson, Dror Avisar

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

A dual gas tracer experiment using sulfur hexafluoride (SF6) and an isotope of helium (3He) and measurements of dissolved noble gases was performed at the El Rio spreading grounds to examine gas transport and trapped air below an artificial recharge pond with a very high recharge rate (∼4 m day-1). Noble gas concentrations in the groundwater were greater than in surface water due to excess air formation showing that trapped air exists below the pond. Breakthrough curves of SF6 and 3He at two nearby production wells were very similar and suggest that nonequilibrium gas transfer was occurring between the percolating water and the trapped air. At one well screened between 50 and 90 m below ground, both tracers were detected after 5 days and reached a maximum at ∼24 days. Despite the potential dilution caused by mixing within the production well, the maximum concentration was ∼25% of the mean pond concentration. More than 50% of the SF6 recharged was recovered by the production wells during the 18 month long experiment. Our results demonstrate that at artificial recharge sites with high infiltration rates and moderately deep water tables, transport times between recharge locations and wells determined with gas tracer experiments are reliable.

Original languageEnglish
Pages (from-to)3939-3945
Number of pages7
JournalEnvironmental Science and Technology
Volume39
Issue number11
DOIs
StatePublished - 1 Jun 2005
Externally publishedYes

Fingerprint

Dive into the research topics of 'Gas transport below artificial recharge ponds: Insights from dissolved noble gases and a dual gas (SF6 and 3He) tracer experiment'. Together they form a unique fingerprint.

Cite this