Heron Cay: Increased Oxygen Reduces Stratification

Posted on November 24, 2010 - 11:13am

Heron Cay, a high-end gated residential development, was experiencing a number of problems in their 21-acre lake which is central to the community. With maximum water depths over 20’, stratification caused severely low oxygen levels at the bottom. Having no beneficial bacteria to break down organics, heavy muck accumulation and foul odors from hydrogen sulfide gases were present. The lake was consuming what little available oxygen there was faster than it could be replenished, and excessive nutrient levels from fertilizer runoff only made conditions worse. The lake’s Biochemical Oxygen Demand (BOD) was extremely high.

The Results

After the design and installation of a Vertex aeration system consisting of 11 diffuser stations being fed by compressors totaling only 2-1/4 horsepower, Heron Cay was set up on a monitoring schedule to determine how lake dynamics were being affected. The results over the 4 month monitoring period were dramatic. Within days of initial start-up, the systems six main objectives were beginning to be realized:

    installing system
  • The breakdown of temperature and oxygen stratification
  • Increased oxygen levels occurred throughout the entire water column
  • Decreased Biochemical Oxygen Demand (BOD) to below detection levels
  • Water clarity increased by 100%, from 3’ to 6’
  • Excessive nutrient levels decreased; nitrogen down 80%, phosphorus down 59%
  • Heron Cay’s lakes are returning to natural, healthy conditions.

Heron Cay graphs