The purpose of the chemical treatment is to restore capacity of the wells. The chemical treatment of the wells shall consist of safe, thorough, rapid mixing of chemicals in a temporary above ground tank, injection of the chemicals-water mixture as described below into the well by high-rate pumping, displacement of the chemicals by high-rate pumping of batch chlorinated water, surging and backfilling the well to help clean and dissolve deposits plugging the well screen, and the removal of spent chemicals and dissolved mineral deposits by pumping to waste. The chemicals-water mixture shall be injected into the well at a high rate to force the chemicals through the well screen and into the gravel pack and aquifer formation as uniformly distributed vertically and radially as possible. The chemicals water-mixture shall be pumped into the well at the rate specified. The Contractor shall cooperate during treatment operations to allow testing by the Department to determine and certify the injection rates. A full and complete written record of all chemicals used, all measurements taken, and a description of the actual well treatment methods and all procedures for each treated well must be furnished to the Illinois Department of Transportation no later than 30 calendar days after completion of the work.
