Featured Case Study

Massive lagoon cover collects biogas, generates revenue and reduces odors

Problem: Melbourne Water Western Treatment Plant in Werribee, Australia, had been harnessing biogas for more than 25 years, but the cover of its anaerobic lagoon was nearing end of life. The replacement cover needed to withstand rugged conditions, manage odors and provide operational efficiencies.

Solution: Geomembrane Technologies partnered with John Holland-KBR Joint Venture to design, fabricate and install a replacement cover. The 19-acre cover has two sections connected by a dual arched central panel. The independent operation of the segments allows for maintenance and cleaning while other segments remain in service. The textured nonslip surface is safe to walk on. The cover is connected to the gas plant with 1,640 feet of large-diameter piping, which includes condensate drainage and emergency vent systems.

Result: The cover collects 78,500 cubic yards of biogas per day, worth $2.78 million per year. It contributes to generating more than 40 percent of the site’s electricity for treatment processes. Greenhouse gas emissions and odors are reduced. 855/484-4630; www.gticovers.com

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Membrane modules allow for easy retrofit

Problem: The Butler (Missouri) Water Treatment Plant draws from an impoundment fed from Butler Lake, the Marais des Cygnes River and Miami Creek. The plant supplies water to more than 300 businesses, four schools, 4,100 residents and four water districts. To combat failures, the city decided to replace membrane modules in three of its four ultrafiltration membrane trains.

Solution: In 2014, Butler conducted a nine-month pilot study with 21 Aqua-Aerobic Systems MultiBore membrane modules retrofitted into Train 2. Train 2 then outperformed the other three UF trains. The city retrofitted the other trains in 2014 and 2015.

Result: The membranes remove 13 to 36 percent more turbidity than the old filters at 24 to 33 percent higher permeability. In addition, the membranes pass continuous indirect and daily direct air integrity testing. The ability to retrofit into the old membrane module racks reduced the upgrade cost and minimized system modifications. 800/940-5008; www.aqua-aerobic.com

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Biostimulant helps reduce odor and carryover

Problem: New Hampshire industrial plant experienced high sludge levels in its aerated basin and polishing pond. The sludge contained cellulose fiber and secondary biosolids. Summer odors and carryover led to neighbor complaints and poor plant performance. State regulators required the facility to implement a solution.

Solution: The plant was treated with Byo-Gon PX-109 biostimulant, applied with a Lagoon Master to mix and help digest sludge in the aerated basin. Additional cellulose-degrading microbes were provided to target fiber buildup, and the process was significantly accelerated by application of the biostimulant, an OMRI-certified natural organic product that increases microbial respiration and improves biological performance.

Result: Cellulose analysis completed by North Carolina State University indicated significant reduction in fiber content. Odors were eliminated and biosolids digestion removed 40 to 50 percent of the settled sludge in the aerated basin. An added benefit was elimination of caustic soda to raise pH in the plant effluent. The plant avoided dredging and disposal costs, which could have threatened continuing operations. 888/296-4661; www.byogon.com

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System enables beneficial reuse of winery wastewater

Problem: In 2015, the Riboli family, which owns San Antonio Winery, was looking to expand into the city of Paso Robles, California. The family sought to pretreat the wastewater to residential levels before discharge to the sewer in order to avoid surcharges.

Solution: Cloacina provided a MEMPAC-I membrane bioreactor that enabled treatment to less than 10 mg/L BOD and TSS. The system allowed for 100 percent reclamation of process wastewater, removing the winery discharge from the city treatment plant. The reclaimed water is used for landscape irrigation, dust control and treatment plant sanitary washdown. The bioreactor system controls the entire process, including lift stations, equalization system, primary treatment, activated sludge treatment, a submerged membrane system, sludge drying, effluent equalization, the stormwater system and the irrigation pump system.

Result: The facility has been online since summer of 2016 and has produced reuse-quality effluent ever since. 888/483-8469; www.cloacina.com

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New dredge unit allows city to reach drying beds

Problem: The city of Ellensburg, Washington, needed to update its 1991 dredge. The new unit would need increased flow and a higher-pressure pump to reach the new drying beds located farther from the lagoon.  

Solution: Mud Cat, Division of Ellicott Dredge Technologies, installed a 40 hp MC-40E dredging system with a 1,000-gpm flow rate at 100-feet TDH and 14-foot operating depth. The slurry pump has an adjustable flow rate, and the unit is equipped with Auto Sense technologies. Remote control allows the operator to see slurry pump pressure, auger cutter-head torque and operating depth in real time.

Result: The city is pleased with the quality and performance of the dredge and the completeness of the operations and maintenance manual. 866/467-4010; www.mudcatdredge.com

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Geomembrane system allows cheesemaker to reclaim wastewater

Problem: A U.S. cheese manufacturer sought an eco-friendly way to recycle its wastewater through anaerobic treatment.

Solution: ADI Systems recommended a custom-designed ADI-BVF system to treat wastewater containing solids, whey, fats and oils. The wastewater is discharged into a downstream membrane bioreactor. The BVF reactor had a combination earthen and concrete structure, and the contents had to be sealed to prevent leakage into the soil or emissions from escaping into the air. The company chose XR Geomembrane Black 8138 XR-5 from Seaman Corporation and cream/black XR-5 material for the protective cover.

Result: The protective cover was effective in preventing leakage. 800/927-8578; xrgeomembranes.com

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Aerators help increase wastewater treatment capacity at winery

Problem: Daou Vineyards and Winery of Paso Robles, California, wanted to expand and upgrade its odorous treatment operation. The company wanted an aerator to sit on top of large, closed-top tanks and saturate the entire volume with dissolved oxygen.

Solution: ClearBlu Environmental installed a package system that uses five 12,000-gallon treatment tanks with a pH balancing system. VaraCorp turbine aerators were installed on each tank. While the aerators normally are used on pontoons in open-water lagoons, the aerator can be decoupled and mounted on batch reactors or treatment tanks.

Result: The increase in aerobic bacteria made it possible to process 10,000 gpd of wastewater at peak harvest with a BOD of 7,000 mg/L. By season’s end the BOD was 78 mg/L, making it suitable for land application. The aerators also helped eliminate odor and produced little noise. 512/847-5026; www.varacorp.com

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High-efficiency media filtration system reduces medical center’s operating costs

Problem: Maintenance costs at a medical center in the western U.S. were increasing; cooling tower basins were being cleaned weekly along with constant replacement of the bag filters. More than 95 percent of the particles in a water sample from the cooling tower were smaller than 5 microns, creating heavy dirt buildup in the system.

Solution: A laser particle analysis demonstrated that a Vortisand system would solve the problem. The high-efficiency system enabled the medical center to reduce cooling tower operating costs while meeting future filtration demands.

Result: Submicron high-efficiency filtration helped reduce particles of less than 5 microns by more than 95 percent. Fine filtration reduced chemical usage. The system helped eliminate the cost of replacing consumable filters. Its small footprint minimized construction costs. Filtration system maintenance was reduced. 888/876-9655; www.evoqua.com/vortisand