28. The owner of a catchment site must, if the periodic testing provided for in the Regulation respecting the quality of drinking water (chapter Q-2, r. 40) shows a nitrate concentration greater than 3 mg/L, notify farm operators who use parcels that intersect with the supply area of the catchment site or, for a catchment site the average flow rate of operation of which is lower than 75 m3 per day, use parcels that intersect with the bacteriological and virological protection areas.