Injection quill for water treatment

First and second quill members introduce water treatment chemicals to a water stream advancing within water containing equipment having only a single opening. The first quill member extends through a sealed opening on a wall of the equipment and has a first inlet located outside of the equipment, a first outlet located within the equipment in the path of the advancing water stream, and a first passage extending between the first and second inlets. The second quill member is mounted on the first quill member and has a second inlet located outside of the equipment and a second outlet located within the equipment in the path of the advancing water stream. The second outlet is spaced from the first outlet and a second passage, coaxial with the first, extends between the second inlet and the second outlet. A first chemical substance flowing through the first passage and issuing from the first outlet into the water stream thereby avoids mixing in a concentrated form with a second chemical substance flowing through the second passage and issuing from the second outlet into the water stream. The outlet tip ends for the outlet tubes are beveled into the direction of flow of the advancing water stream and each beveled tip end may have a notch formed at an extremity to increase turbulence. The first and second outlets are preferably located at maximum distances from each other and from the walls of the water containing equipment.