Pond Aeration and Lake Restoration Case Studies
Check out our poster case study of Silver Lake: Reduction of microsysitin counts/blue-green algae, and overall algal biomass Click here.
Bahia Del Mar Lake Restoration
Vertex Aeration Eliminates High Hydrogen Sulfide Emissions - Watch the Video
Bahia Del Mar is a 14 acre lake located in St. Petersburg, on the western coast of Florida. In January, 2012, the Home Owners Association contacted Aquatic Systems, Inc. to request assistance in dealing with multiple lake issues including intense odors, ongoing fish kills and algal blooms.
This lake system was severely stratified, with large amounts of organic material in bottom waters, extremely high nutrient levels and high concentrations of hydrogen sulfide causing a “rotten egg” odor, high biological oxygen demand and very low oxygen levels. The system was unsuitable for fish and other aquatic organisms and posed a health risk to residents due to the intense noxious fumes being produced as a result of the hydrogen sulfide emissions from the lake. Due to the extreme conditions of the lake a two-pronged approach was undertaken to bring it back to a healthy state.
- Aeration: Bathymetric Mapping provided accurate detail about the depths and volume. Two Vertex Systems, an LL 4XL5 Aeration System and a HF 4XL5 Aeration System with sound kits were installed in April, 2012 to provide adequate turnover rates.
- Alum application: After extensive laboratory trials to determine the most effective application, Aquatic Systems applied two treatments of Alum at a rate of 60ppm to improve water clarity and reduce water phosphorus levels.
- BOD at the bottom of the lake went from 385 mg/L to 2.5 mg/L – a 99% reduction
- “Rotten Egg” Odor eliminated – Hydrogen sulfide in the water column went from >5 mg/L to 0 mg/L – a 100% reduction
- Oxygen at bottom of the lake went from 0 mg/L to 8 mg/L
- Turbidity went from 113 NTU to 8 NTU – a 92% reduction
- Bottom water Phosphate went from 8137 µg/L to 35 µg/L – a 99% reduction
- Bottom water Nitrogen Ammonia went from 109,250 µg/L to 800 µg/L – a 99% reduction
- Algal abundance (Chlorophyll a) went from 87 µg/L to 24 µg/L – a 72% reduction
Download the Lake Restoration Case Study PDF
Heron Cay Increased Oxygen to Promote Stratification Reduction
|Heron Cay, a high-end gated residential development in South Florida, was experiencing a number of problems in their 21-acre lake which is central to the community.|
With maximum water depths of over 20 feet, stratification had resulted in a lake with 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.
With the brunt of summer approaching, Heron Cay had a very real potential for a serious fish kill. Action needed to be taken, so the residents looked to Vertex to provide them with an efficient and cost effective method of bringing their lake system back to a healthy state.
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 four month monitoring period were dramatic.
Within days of initial start-up, the four main objectives were beginning to be realized:
- The breakdown of temperature and oxygen stratification - the lake's water was being circulated.
- Increased oxygen levels throughout the entire water column - creating a healthy environment for both fish population and beneficial bacteria.
- Decreased the lake's Biochemical Oxygen Demand (BOD) - oxygen was no longer being consumed faster than it was being replenished.
- The residents of Heron Cay are no longer in danger of oxygen-related fish kills, odors have been eliminated and the lake is returning to natural, healthy conditions.
"I've never seen the lake look better"
- Mark Sanderson, President, Heron Cay HOA
Download the Destratification Case Study PDF
Winston Park: Nutrient reduction and oxygen transfer efficiency in a South Florida retention pond using artificial destratification aeration
- Amanda Quillen, Ph.D.
Winston Park is a residential community in subtropical Coconut Creek, Florida. The study lake is a borrow pit and retention pond surrounded by landscaped lawn and partially by single-family homes. Winston Park Lake is 12.7 acres (5 hectares) and has a maximum depth of 32 feet (10 meters) with an average depth of 19.5 feet (6 meters). The lake experienced massive fish kills every fall due to a reduction in oxygen during fall turnover, so Vertex installed an aeration system consisting of six XL5 AirStations© powered by 3 Brookwood© compressors totaling 2.25 hp which produced 14 CFM of air at 19 PSI. This system is sized to turn the water over in the lake at a rate of 0.8 turnovers per day. In February of 2009 the system was turned off.
- Orthophosphate levels were reduced 97%
- Ammonia levels were reduced 55%
- Biological oxygen demand (BOD) declined 60%
Stratification was most enhanced at the beginning of and during the startup period rather than at the beginning of the sampling period due to hot weather between the June 3 and June 15 sampling dates. Rainy, cloudy, stormy weather leading up to the end of the startup period likely led to more rapid destratification of both temperature and oxygen profiles than may have occurred with aeration alone.
Download the Nutrient Reduction Case Study PDF
Independent Study: Vertex Lake Aeration Eliminates Accumulated Sediment
East Twin Lake in Michigan muck reduced an average of 2.8' in 10 years
"A community project removed over 90 dangerous timbers from the lake in 2002. In clearing the lake from these obstructions, discussion turned to the noticeable levels of sediment in East Twin Lake, primarily concentrated at its west side. Was this sediment a sawdust gift from our timbering forefathers that was stored on our sandy-bottomed lake? In 2002, we were determined to come to the aid of our upper mesotrophic lake. We were not satisfied seeing our lake filled with unsightly and increasing sediment.
East Twin is a relatively shallow lake. Depths range four to eight feet, with some areas no deeper than about 26 feet. The lake bottom is primarily a hard sandy surface. During a period of low water levels, the high sediment level at the western end of our lake became more prominent. The sediment occupied as much as six of the eight feet of depth in many locations. These levels were unacceptable to boaters, water enthusiasts, and fishing aficionados. Our problem area is located at the western end of our lake. This area consists of 160 acres of surface area. An existing island on our lake and a sand bar, which traverses from the island to the northern shoreline, roughly contains it.
How could we rid our lake of this unacceptable sediment? In July 2004, eight Vertex Air3 XL4 Systems were installed throughout the cove at the west end of the lake. " - Twin Lakes POA
Muck reduced an average of 2.8' in 10 years, oxygen levels restored and excessive BOD eliminated.
Download the Muck Reduction Case Study
Aquatic Midge Fly Swarming Controlled with Vertex Aeration
90% Reduction in just 16 months without pesticides
Hibbs Grove located in Cooper City, Florida was experiencing an ongoing outbreak of swarming non-biting midge flies (Order: Diptera, Family: Chironomidae) from their 6.5 acre lake preventing residents from enjoying their lakefront property. Sampling indicated an extreme infestation of midge larvae averaging 6,794 larvae/m², more than six times the recognized 1,000/m2 nuisance level.
Hibbs Grove turned to the biologists at Vertex Water Features for an environmentally safe solution. Vertex installed a CoActive Air 5 aeration system that provided compressed air to five XL2™ CoActive AirStations placed at the deepest points throughout the lake, effectively circulating the entire water column 0.76 times per day.
Oxygen levels increased immediately and accumulated organic muck on the bottom began to decompose thereby eliminating the habitat and food source that the midge larvae depended on. The improving water quality allowed predators of the midge fly, such as bluegill and aquatic insects to prey on the midges. The resulting increased predation, decreased nutrients and habitat competition contributed to a significant decrease in midge fly numbers.
Within 16 months of the Vertex system installation, the midge fly larvae population had been reduced by 90 percent, from 6,794 larvae/m2 to just 660 larvae/m2. Throughout the 16 months, there had been a visible increase in fish, dragonflies and water beetles all of which are natural predators of the midge fly larvae. With continued aeration, the oxygen levels have remained elevated and continue to oxidize bottom muck and suppress the midge fly population.
Download the Midge Fly Reduction Case Study