variation in total solids across different units of water treatment plant
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On a typical hot summer day, Cañon City water customers use enough treated potable water to cover 31 football fields one foot deep in water! In the winter the usage drops to about 9 football fields worth a day. Before reaching the faucets of Cañon City residents, however, city water goes through an extensive treatment process.
The Cañon City Water Treatment Plant is a conventional surface water treatment plant that diverts water from the Arkansas River to produce drinkable (potable) water, which meets or exceeds all EPA Safe Drinking Water Act and the Colorado Department of Public Health and Environment Primary Drinking Water Standards.
The water treatment plant is located on the hillside west of Cañon City. The water plant has the ability to produce up to 22 million gallons of safe drinking water every day. On average only about 3 million gallons per day are made in the winter; however during the hot summer months when there is an increased demand for lawn irrigation water produced can exceed 10 million gallons per day.
Devices known as programmable logic controllers (PLC’s) that are networked together with other PLC’s control the water treatment plant and the treatment processes. The PLC’s track over 1,500 signals or data points to ensure optimized treatment. The computer signals and data are collected by the Supervisory Collection and Data Acquisition (SCADA) system and provide information to the Operator on shift whenever any item requires Operator intervention.
Water Treatment Process Diagram (Coming Soon!)
Arkansas River Diversion
The Arkansas River solely supplies Cañon City’s drinking water. The Arkansas River begins as snowmelt near Leadville, Colorado at the Continental Divide. It flows south and southeast through Cañon City, to the Pueblo Reservoir. From the reservoir it then flows into the lower Arkansas Valley and eventually leaves the state east of Holly, Colorado. Water taken directly out of the river is NOT SAFE TO DRINK due to bacterial and parasitic conditions. It would probably make a person sick from ingesting pathogenic bacteria and parasites such as Cryptosporidium and Giardia. The water to be treated is pumped out of the river and is piped underground into our raw water settling pond.
Raw Water Settling Pond
The raw water-settling pond holds the water diverted from the river for a couple of purposes. The primary purpose of the raw water-settling pond is to allow much of the sand and debris to naturally settle out of the water before it is pumped to the water treatment plant. Secondarily, the pond allows for some capacity in the event that the river water is muddy or if an accident on U.S. Highway 50 spills contaminants into the Arkansas River. The pump station on the river can be shut down and the plant can use the ponds’ water for supply until the river water is clearer or safe to use again. Also, if something were to happen to the underground piping from the pump station on the river to the pond, the water in the pond can be treated until the problem is fixed. A second pump station lifts the water to the water treatment plant headworks. A backup pump station that is supplied water from the Hydraulic Ditch can be used in the event that the pump station on the river is out of service due to issues whether they are electrical or mechanical. However, this water is pumped directly to the water treatment plant headworks by-passing the settling pond thus losing the benefit of settling the heavy sand, grit and debris.
Pre-Sedimentation
The Pre-Sedimentation Building is where the treatment process really begins. The raw water from the settling pond is lifted 240 feet up to the water treatment plant. The raw water is delivered to the headworks of the water treatment plant where the first of 5 major unit water treatment processes start the treatment to make the water safe to drink. The 5 major unit processes include chemical coagulation, flocculation, sedimentation, filtration, and disinfection (described below). There are chemicals added to the water as it enters the various treatment processes.