The Immokalee Water and Sewer District owns and operates a wastewater collection and treatment system that consists of four treatment trains. Three of the clarifiers are 30+ years old and need substantial upgrades. The internal metal parts in each tank were badly corroded, making even routine maintenance difficult. All three clarifiers were repaired several times previously and one suffered a severe failure that required emergency repairs. The District selected Weston & Sampson to assist with a funding application through a United States Department of Agriculture (USDA) grant and loan program to upgrade and modernize the existing tanks. After receiving the funding, the District retained us to provide a full suite of services for the project, including design and permitting, plans and specifications, bidding assistance, and construction administration.
For the first tank, Weston & Sampson cut out the flat tank bottom and replaced it with a sloped bottom to assist with the settling process. We are also installing new centerfeed clarifier mechanisms to replace the old peripheral-feed mechanisms, which involves modifications to the clarifier piping. Since the existing tanks are partially buried and the new weirs will be located along the perimeter of the tank instead of in the middle, the modification will increase operator safety during weir maintenance. To further assist with future maintenance and cleaning needs, an automatic brush system will be provided for the peripheral weirs. We also designed and are installing an upgraded system of scum pits and scum pumps to remove scum and foam from the process and convey it to a storage tank for landfill disposal.
Once the first clarifier is complete, we will assess and upgrade the other two clarifiers. These modernization efforts will significantly increase the plant’s efficiency and decrease costs, and once the upgrades on all three tanks are complete, the District will be better able to safely perform routine periodic maintenance. These improvements will also increase the overall reliability of the wastewater treatment plant and reaffirm the rated plant capacity.
Key Project Features:
- municipal wastewater system
- USDA loan & grant assistance
- planning, design, and permitting
- bidding assistance
- construction administration
- reduced maintenance costs
- increased plant efficiency & reliability