Abstract
Ground water withdrawals in the United States make up roughly one-fifth of the total water use in the United States. For this reason, it is one of our most important resources which must be, protected from contamination. The occurrence of human enteric viruses in ground water, however, has been well documented. Viral contamination of ground water from septic tank, sewer line, or waste disposal site failures has lead to increased efforts to quantify the transport of viruses through the ground water. Ground water transport models can be used to predict the transport of viruses. However, if current public domain virus transport models are to be used for this purpose, they need to be verified under operating field conditions. To evaluate these models it is useful to use data from a "worst case scenario" for contaminant transport: a sand and gravel aquifer under a forced gradient. Field studies have been conducted to trace large-scale (34 in) and small-scale (10 in) virus transport under a forced gradient through the sand and gravel aquifer at the ground water research site and the Texas A&M Research Farm. Field instrumentation was developed to inject and monitor the virus tracer. Virus transport was monitored under natural and forced gradient conditions using MS-2 and PRD-1 bacteriophage as virus tracers and bromide as a conservative tracer. Simulations of the virus transport at the research site were also completed using the VIRALT virus transport model and parameters taken from past studies at the site. Results indicate virus and bromide transport in both the large and small-scale field tests, although comparison of the results of the two large-scale and the two small-scale was not consistent. These differences can be attributed to the heterogeneity of the sand and gravel aquifer at the site, different injection methods, and different sampling methods. The VIRALT simulations completed for virus and bromide transport at the site compared favorably with the field data.
Vogel, Jason Robert (1997). Field studies of virus transport in a heterogeneous sandy aquifer. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1997 -THESIS -V64.