12VAC5-630-430: Disinfection

A. Private wells shall be disinfected before placing the well in service.

B. Methodology. Disinfection shall be accomplished by one of the following methods:

1. Maintaining a 100 mg/l solution of chlorine in the well for 24 hours utilizing the dosage rates set forth in 12VAC5-630-470.

2. Applying a quantity of water/chlorine solution to ensure a minimum of 100 mg/L of available chlorine throughout the well and immediate formation materials. Disinfection contact time shall be established on the basis of contact units, which are calculated as mg/L chlorine multiplied by hours of exposure. Contact time shall equate to a minimum of 1,000 contact units (50 mg/L chlorine x 20 hours = 1,000 contact units; 200 mg/L chlorine x 5 hours = 1,000 contact units; etc.).