Water is a precious resource needed by all living things. Kingsport is lucky to have such a great water source right here in our city and it’s our job to make sure it stays clean for years to come. One way our city is ensuring this is through the Raw Water Intake project.
The purpose of the Raw Water Intake Project is to ensure a safe, reliable and continuous supply of drinking water to meet the needs of our current customers and for generations to come. It includes construction of a new raw water tunnel and a new raw water pump station at the water treatment plant, eliminating of the use of existing pumps and transmission lines.
Our drinking water comes from the South Fork Holston River. The intake is located approximately two miles below the dam and upstream from industry. Water is pumped through raw water pumps and then flows through three transmission pipes to the water treatment plant for treatment.
The existing pump station was built in 1970. The three current transmission pipes were installed in 1928, 1946 and 1977 respectively. The transmission pipes run vertically up an 85 foot rock bluff and are exposed to all the elements, such as snow, rain and summer heat. The configuration of the pipes also has potential for single points of failure. The age, layout and condition of these pipes are what makes this a critical project.
In 2010, a master plan was developed for the water treatment plant and distribution system. The city hired the engineering firm, Hazen and Sawyer, to evaluate existing facilities, current/impending water regulations and water usage. The master plan is the source used to identify and plan for infrastructure replacement. The Raw Water Project was identified as a serious need and the first project to roll out of the master plan.
Several alternatives to the Raw Water Intake Project were evaluated before deciding on the current project solution. In 2012, another engineering firm, CDM Smith, was hired to evaluate alternative solutions. A total of nine alternatives were evaluated and their solutions ranged from replacing the pipes to utilizing an existing storm water drain. In the end, the most practical and safe solution was to bring the river to the plant by gravity instead on transmission pipes and relocate one of the pump stations to the water treatment plant.
The raw water will flow by gravity through a new 7.5 feet high and 7.7 feet wide horseshoe shaped tunnel from the South Fork Holston River to the water treatment plant. The tunnel will replace the existing pipes that have reached the end of their useful life. One of the existing pump stations will continue to serve as the intake structure and convey water from the river to the vertical shaft at the head of the tunnel. The vertical shaft is 24 feet in diameter and 38 feet deep. Water will flow 1100 feet from the vertical shaft through the raw water tunnel to the water plant. The tunnel terminates approximately 130 feet below the surface at the water plant. Four vertical shafts connect the tunnel to the raw water pump station and four vertical turbine pumps lift the water to the water plant for treatment.
The $13.7 million project is funded through a 1.78 percent low interest Tennessee State Revolving Loan and a $1.5 million EDA grant. It has a 20-month construction schedule. Construction on the project began last fall and the tunnel is nearly complete, with the estimated completion of the project being middle of October. The new pump station project will be completed in May of next year.
The Wastewater Treatment Plant is Kingsport’s only water treatment facility. It will remain the primary source of drinking water for the area for many years to come. Therefore, its continued reliable operation is both necessary and vital for protection of human health and continued growth and sustainability for this region.
For more information about the Raw Water Intake project, check out the video here.