This mill housed a set of machinery that processed raw material into finished products. It produced flour from grain, thus it was a gristmill. The milling complex also powered a saw and at one time a cider mill.
Amos Janney's small original mill was powered directly from the flow of Catoctin Creek. To achieve greater and more consistent power, Mahlon Janney dammed the stream and diverted the water from behind the dam through a mile-long channel or headrace, delivering it through a sluice and gates to the top of a large wooden wheel. The weight of the falling water turned the wheel. A series of gears and belts transferred the power of the rotating wheel to the mill and sawing machinery.
Grain delivered for milling was first screened and cleaned, then weighed. Initially, the Waterford Mill ground wheat to flour between large grooved burrstones. It is believed that the machinery was of an Oliver Evans design, which used as series of cups, belts and wheels, all operating from one water wheel, to pass the grain through the mill.
In 1885, roller-process machinery was installed. That more advanced process used a gradual reduction method, passing the grain through a series of rollers until the flour was of the desired fineness. The flour was then bolted, or sieved, to remove any bran particles. The final product was packed in barrels or bags and hauled to market.