See Hydrology Comments for additional information on groundwater impacts.

The area of the proposed development, although underdeveloped residentially, has some high water use commercial buildings immediately surrounding the site to the east and north. The deep drilled wells proposed for just Phase 1 (46 units plus 11,477 square feet of commercial space) would change flow direction and volume available to abutters, and would draw down the water table, affecting shallow dug wells and disturbing wetlands. This was assessed in three ways: 1) water mass balancing, 2) testimony from abutters that have well problems related to previous land development, and 3) two hydrogeologists’ interpretations of pumping tests for the subject property.

1) Water Mass Balancing
Mass balancing is a method used by hydrogeologists and land use planners for assessing the groundwater carrying capacity of an area for development, usually where there is no public water and/or sewers. It balances the groundwater mass available with the mass demands, to determine the amount of groundwater left over to supply new development. This can be calculated in terms of number of dwelling units on a defined area of land.

A water mass balance analysis carried out for the site and village area surrounding the proposed development, using normal accepted hydrogeological methods and considering existing water demand, has determined that only 12 more dwelling units can be supported and sustained by the available groundwater. A report detailing the scientific basis for these statements is available for download here and has been reviewed and verified by an independent senior hydrogeologist with over 35 years experience.

2) Testimony from Abutters with Well Problems
Existing neighbours to the site, on Danny’s Lane, have experienced loss of water from previous development. They expressed in writing that their dug well went dry 25 years ago after development of the adjacent commercial mall. Their other dug well lost considerable water depth when another commercial well was installed in the aquifer. This demonstrates a direct connection between the deep water supply and the shallow wells. Other neighbours have also indicted problems with dug wells.

3) Hydrogeologists’ Interpretations of Pumping Tests
The proponent’s consultants carried out a groundwater pump test that was reviewed by two senior professional hydrogeolgists. Following is a brief summary of concerns raised in the review:

  • The pump tests were done in February when groundwater levels were at their highest and no allowance was made for conditions during the lowest groundwater levels that normally occur in fall, which happens to coincide with high season use of an important commercial abutter.
  • Results of the pump tests do not consider regional changes in groundwater level such as climate change effects and water diversion due to development.
  • Considering that the proposal includes sewage treatment that discharges directly into the sea, there will be no groundwater recharge as there would be with onsite sewerage treatment. This has not been considered by the proponents.
  • Effects of groundwater withdrawal on neighbouring wells have been shown to exist and have not been considered by the proponent.
  • The effects of drawing seawater into the freshwater aquifer due to heavy pumping have been discounted by the proponents, but the pumping test on which that conclusion was made was short (72 hours), and still had effects of pumping extending a considerable distance towards the ocean.

Phasing of Analysis
In analyzing the groundwater impacts for this proposed development, the proponent’s consultants divided the proposed project into Phase 1 and Phase 2. Only Phase 1 (46 multi-family units plus 11,477 square feet of commercial space) has been analyzed for groundwater impacts, and this represents only 44% of the groundwater needs for the whole proposed development.

Enough Groundwater for Just Phase 1?
Potential impacts on groundwater wells and wetlands is the most important determinant of sustainable density for this proposed development. Independent analysis of water mass balance has shown that the site cannot support more than 12 units during peak use season without borrowing water from adjoining properties;
however, the adjoining commercial properties are already borrowing water from the subject site. That is the problem.

Further Research Needed
Although we have not yet seen the developer’s consultants’ latest revisions to their hydrogeology (groundwater) report, what we have seen so far did not quantify the surrounding commercial demands to the extent that we did in our analysis, and considered only 210 meters from their proposed wells to be the zone of pumping influence, which omits some commercial abutters whose wells were not pump tested. According to Nova Scotia law, the groundwater needs of existing commercial and residential land users must be given priority over the groundwater needs of a proposed development in a groundwater withdrawal application. (The developer has not yet
applied for this but will need to.) Thus, more research on this is needed. In addition, more analysis needs to be done to determine if holding tanks with reserve water can adequately smooth out water demands during peak use times, and if water conservation measures can adequately reduce water demands during average use times.