Soil and groundwater description, characterisation and sampling at various sites at Cape Hallett

The soil and groundwater at Seabee Hook, Cape Hallet was described and characterised. Soil Investigation: Soil pits were dug east of Willett Cove on low mounds on disturbed and undisturbed sites, both hydrocarbon contaminated and hydrocarbon free at Seabee Hook, Cape Hallett to describe, sample and characterise each of the identified soil-landscape map units. 13 soil profiles were described and 7 were sampled for soil chemical, physical and microbial analyses. In situ soil respiration rates were measured. Analysis of chemical and physical properties included soil pH, electrical conductivity, soluble salts, carbon, nitrogen, total petroleum hydrocarbons, particle-size distribution, soil moisture retention, hydrocarbon degradation potentials and bacterial diversity.

Groundwater Investigations: 9 piezometers were placed in the soil in the area between the fuel tank and Willet Cove in order to allow the sampling of the groundwater, to test the extent of fuel migration and to determine the groundwater regime of the site. The piezometers were left with the pipes visible up to 20 cm above the soil surface and capped with a wooden top. Groundwater samples were collected for hydrocarbon analysis, hydrocarbon mineralization potentials and chemical analysis. Measurements of the rate and direction of groundwater flow and subsurface soil permeability on Seabee Hook was measured by installing dipwells. The duration and extent of groundwater occurrence and movement was monitored with a bromide tracer. A groundwater model of the area was prepared.