Raw water enters facilities at the Lehigh River Intake where activated carbon is added to reduce color, taste and odors. The raw water is pumped via a 16-inch pipe to the Water Treatment Plant. Additional supply is available by gravity from the Spring Mill Reservoir. These supplies can be used independently or in combination.
At the treatment plant, which currently has a capacity of 8.0 million gallons per day, water flows by gravity through four treatment steps. First, chemicals are added to and mixed with the water as it enters the "rapid mix chamber." The chemicals condition the water to assist in the removal of iron, manganese and suspended solids in subsequent stages of treatment. Chlorine is used to disinfect the water. After rapid mixing, the water flows in "flocculators" where slow gentle mixing occurs for 20 minutes to form "floc," large particles suitable for removal by settling.
The water then flows through the "sedimentation basins" in which some of the "floc" settles to the bottom. Approximately 80% of the suspended solids are removed in these basins. The clearer water from the top of the basins flows to the filters where it is strained through a granular media bed consisting of 18 inches of anthracite and 12 inches of sand. Any suspended solids remaining in the water are removed as the water passes through the filters.
The water then enters the clearwell where post-chemicals including chlorine are added so that the water remains free from disease-producing organisms and other undesirable substances as it travels through the distribution system. This completes the treatment process.