Winston Park Nutrient Reduction
Posted on November 7, 2018
Winston Park is a residential community in subtropical Coconut Creek, FL. The study lake is a borrow pit and retention pond, surrounded by landscaped lawn and partially by single-family homes. Due to a reduction in oxygen during fall turnover, this lake experienced massive fish kills every fall. Vertex installed an aeration system sized for 0.8 turnovers per day based on the lake’s dimensions:
- 12.7 acres (5 hectares)
- Maximum depth of 32 feet (10 meters)
- Average depth of 19.5 feet (6 meters).
Nutrient reduction and oxygen transfer efficiency using aeration
This study shows that aeration allows a greater volume of water to come in contact with the water-atmosphere interface. The interface is where oxygen transfer takes place in lakes and ponds. Also, nitrogen and phosphorus levels where tested throughout the process to see if aeration leads to nutrient reduction.
Testing Completed to Determine Aeration Efficiency
We measured the lake’s oxygen levels during the startup of the system. This allowed us to estimate the total transfer of oxygen brought about by aeration. The sampling took place in the middle of the lake, in between aerators. The follow tests where regularly performed:
- Secchi disc
- Site samples – pH, oxidation-reduction potential (ORP), specific conductivity, dissolved oxygen (DO), and temperature
- Lab samples – turbidity, apparent color, ammonia nitrogen, phosphate, carbon dioxide (CO2), Nitrate, TP and TN
- On some occasions biological and chemical oxygen demand (BOD & COD) were performed
Mapping: A 3-dimensional bathymetric map accurately estimated lake volume and surface area. This information helped to determine the efficiency of the system.
Nutrient Reduction and Oxygen Demand Results
Nutrient Reduction: Levels of phosphate at the sediment line declined by 97%. Ammonia levels decreased 55%. Biological oxygen demand (BOD) improved steadily, decreasing 60% from the start of the study. This shows that nutrient reductions occur and likely due to increase in ORP.
The combination of rainy, windy, cloudy weather combined with an efficient aeration system destratifies temperature and oxygen levels faster.
Do you Need a Consultation for Your Lake?
Vertex Aquatic Solutions, founded in 1977, is the professionals’ choice for research based scientific consulting services, aeration systems, floating fountains, bubble curtains and biological products to enhance water quality in lakes, ponds, canals, marinas and reservoirs. As respected leaders in the lake management industry the Vertex team of aquatic biologists, limnologists, fisheries scientists and engineers work together to deliver science-based, environmentally sound solutions to complex waterbody issues. Our products and services are delivered through an international network of qualified, experienced waterbody professionals who provide local support, service and pond management expertise to customers.
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