Applications of seepage meters in lakes with slight bottom sediments in fractured rock basins have not been reported. A study of the hydrogeology of Long Lake, at Halifax, Nova Scotia, used seepage meters in this situation. Fifteen meters were installed in the 1.7 km2 lake — seven in a line extending from the shore, the remaining eight on the lake periphery. Seepage measurements were made monthly over 1 year. Groundwater levels were measured in boreholes in the fractured granite of the watershed. A positive inflow of groundwater to the lake occurred through the year, seepage flux at the shoreline meters varied from 0.15 to 0.78 mL∙m−2∙s−1, with no consistent seasonal variations. Seepage decreased exponentially with offshore distance. A linear relationship was evident between water levels in a borehole near the shore and rate of seepage at the closest meter. Chloride applied to this borehole was reflected in elevated chloride concentrations in seepage collected by the meter. Key words: seepage meter, groundwater – lake system, fractured rock tracers.

Numerical simulation studies are perfonned to investigate the effects of air and liquid water drilling on the time-dependent moisture conditions in nearby fractures and rock matrix blocks. The results obtained suggest that drilling with liquid water will increase the liquid saturation in the matrix by one or two percentage points after one year of recovery. For the characteristic curves used, this corresponds to a 10 to 20 percent increase in the relative permeability of the liquid phase. The results also indicate that air drilling has negligible effects on the moisture conditions within the matrix blocks.

A new technique for calculating hydraulic properties of unsaturated fractured for mations is proposed as an alternative to the common approach involving steady-state analysis of multi-rate gas injection tests. This method is based on graphical analysis of unsteady-state pressure-time data from an injection-falloff test sequence. Both gas and water injection testing are considered. Flow in a horizontal fracture of limited lateral extent, bounded above and below by an impermeable matrix, and intersected by a cylindrical borehole is described by two analytical models developed in this study. The first model corresponds to the early-time infinite acting radial flow period, and the second to the late-time linear flow period. Interpretive equations are derived for comput ing fracture conductivity and volumetric aperture from early-time pressure data, and fracture width from late-time pressure data. Effects of fracture inclination and gravity are studied numerically and found to be practically negligible for gas as well as water injection. Two simulated injection-falloff tests are analyzed using the suggested pro cedure. Results are found to be in good agreement with simulator input values.