ESTIMATION OF ALPHA(L), VELOCITY, K-D AND CONFIDENCE-LIMITS FROM TRACER INJECTION TEST DATA

Bromide and boron were used as tracers during an injection experiment conducted at an artificial recharge facility near Stanton, Texas, The Ogallala aquifer at the Stanton site represents a heterogeneous alluvi al environment and provides the opportunity to report scale dependent dispersivities at observation distances of 2 to 15 m in this setting, Values of longitudinal dispersivities are compared with other publishe d values. Water samples were collected at selected depths both from pi ezometers and from fully screened observation wells at radii of 2, 5, 10 and 15 m. An exact analytical solution is used to simulate the conc entration breakthrough curves and estimate longitudinal dispersivities and velocity parameters, Greater confidence can be placed on these da ta because the estimated parameters are error bounded using the bootst rap method, The non-conservative behavior of boron transport in clay r ich sections of the aquifer were quantified with distribution coeffici ents by using bromide as a conservative reference tracer.