4. The carrying on on land of an industrial or commercial activity in a category listed in Schedule IV is subject to the monitoring of groundwater quality, in accordance with the following provisions, if a catchment installation for surface or groundwater intended for human consumption is situated less than 1 km downstream from the land.
Where the catchment installation referred to in the first paragraph is built after the industrial or commercial activity has begun, the groundwater monitoring requirement applies only after the expiry of the sixth month following the date on which the person carrying on the activity is informed of the existence of the installation.
The groundwater monitoring requirement prescribed by this section does not apply if it is shown that the industrial or commercial activity carried on on the land is not likely to alter the quality of the water referred to in the first paragraph by substances listed in Schedule V. If that demonstration is based in whole or in part on the land’s prevailing hydrogeological conditions, it must be signed by an engineer or a geologist who is a member of an order governed by the Professional Code (chapter C-26).