The final arcMap DRASTIC output layers, one for dry months and the other for the wet months, indicate spatial variations in aquifer vulnerability across Hornby Island in addition to spatial variations between the wet and dry months. The red indicates that there is high aquifer vulnerability and the blue indicates low aquifer vulnerability.

For the dry months of the year there is less vulnerability to aquifer contamination across the island as there is less precipitation available for the transport of contaminants. There are several high vulnerability locations in the dry months that are important to note. Galleon, Sandpiper, along Central road, near Little Tribune, Phipps Point and Single Spit, Fords Cove, and Strachan Valley, all of which have locations of very high vulnerability to aquifer contamination. For the wet months of the year, these locations all increase in vulnerability as the vulnerability spreads out further from these hot spots. For example, the entire Galleon subdivision increases a considerable amount in aquifer vulnerability from the dry months to the wet months.

The locations that have a low vulnerability to aquifer contamination appear to be at high elevations, like Mount Geoffrey and along High Salal. In addition, it appears that the Whaling Station Bay subdivision and along Anderson Drive has a moderately low vulnerability. The low vulnerability of these two areas may be due to the lack of well logs for the area. We found that the wells logs for this area that had the depth to water table recorded happened to reach the water table at deeper depth than other locations on the island. By using this data we might have implied that the depth to water table is greater than its actual depth and therefore it’s less vulnerable to aquifer contamination. The low vulnerability of Mount Geoffrey and High Salal raises concern for us as it conflicts with previous studies done by Dr. Allen. Dr. Allen’s study determined that these two locations were the main recharge locations for the Island and therefore we think that there should be a high vulnerability to aquifer contamination (Allen 2002).

In turn, the outcome of this aquifer assessment is unclear and further studies are needed to determine if or how this may affect water quality and quantity supply on the island.