Bioremediation Case History - Belvedere Lake, East Los Angeles, California
Belvedere Lake at East Los Angeles Civic Center is part of Belvedere Community Regional Park, a recreational hub of the community located in the heart of East Los Angeles. Belvedere Lake is pictured in the image above.
Case History
In the mid 1980s Belvedere Lake was drained, dredged, lined and the edge concrete capped. Then clay, soil, 8” of Zeolite, calcium carbonate, soil and gravel were added, as well as six aerators. The average depth was 3.5 feet. Water chemistry became unbalanced due to a number of factors:
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The Zeolite once saturated released the bound ammonia back into the water. |
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Calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases. Producing an unbeneficial substrate for biota. |
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High temperature, little circulation and aeration and lack of sufficient depth meant oxygen levels plummeted. |
This resulted in abundant algal growth and fish kills. As a solution aluminum and copper sulfate were added to combat these effects as well as physical weed removal. All failed to clear up the lake and balance the ecosystem.
Emergency Cleanup
AquaBio was called in for emergency cleanup and carried out the following:
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Phase I - Baseline data was recorded and a program was devised to control weeds, degrade organics and reduce odors. |
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Phase II - AquaBio cleaned the lake up of the herbicides and the weeds through manual weed removal and administering a topical prescription of microbes to stabilize the lake. |
Public Works Recommendations
AquaBio gave Public Works recommendations for the redesign of Belvedere Lake. In 2001 Belvedere Lake closed for remodeling with the following changes:
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Circulation in the water runway. |
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14 industrial skimmers. |
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6 new aerators. |
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New pumping system. |
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2 fountain fish sculptures. |
More Emergency Cleanup
A few months after re-opening, AquaBio was again called in for emergency cleanup after eleven pine trees were sunk for fish habitat. The pine trees’ terpehenes and degrading organics reduced oxygen levels, which led to fish kills and heavy odors.
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Phase I – Tree removal. |
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Phase II – Manual weed removal and administration of a topical prescription of microbes to clean and balance the lake, which was achieved in six weeks. |
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Phase III – Habitat Restoration. Biota from other healthy lakes, under the management of AquaBio, was introduced throughout the lakes’ bottom, creating a “living lake”. |
Current Condition
Belvedere Lake holds biannual fishing competitions and the bluegill, bass and catfish present in the lake have successfully reproduced replenishing the population. AquaBio has managed this lake successfully maintaining a clean balanced ecosystem. Belvedere Lake is pictured in the large header image above. (Before & After shots)
Bioremediation Case Study 14 - Composting Facility, Northern California
Our client runs a composting facility that receives green waste, food waste and other compostable material from residential and commercial sources, to create rich, black compost for sale.
Challenge
As part of the facility, the compost leachate pond has repeatedly experienced problems with the incoming influent high chemical oxygen demand (COD) and biological oxygen demand (BOD) levels, foul odors and acidic black water. Previously, the pond was drained and the sludge manually removed annually, later a costly paddle aeration system was installed, both proved ineffective in tackling the ongoing problematic issues. AquaBio was hired to bioremediate the incoming leachate and pond, reduce odors, and bring down BOD and COD, after local residents had complained about the foul odors.
Solution
A simple bioremediation management plan was devised by AquaBio, including pH adjustment prior to the start of the weekly bioaugmentation prescription of microbes and installing a new cost effective Vertex micron diffusion aeration system. AquaBio’s bioremediation management plan helped to deal with the odor issues and reduce BOD and COD. The leachate pond was monitored to determine how the system was doing, giving impressive results over a six month period.
Results
The results show a dramatic reduction in both inorganic and organic parameters measured.
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BOD reduced 98.7% (Figure 1.2). |
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COD reduced 93.9% (Figure 1.2). |
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Nitrates reduced 89.3 % (Figure 1.1) |
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Phosphates reduced 83.7% (Figure 1.1). |
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The odor was notably minimized. |
