Secondary treatment units specified for subdivision

Problem: An Arkansas developer wanted to build a subdivision outside the range of city sewer service. To maximize property development, at least 260 homes were needed on the 60-acre development, including wastewater treatment and disposal. A compact wastewater treatment system needed to maximize development and meet a 100-foot residential setback requirement. To save space, an NPDES surface discharge permit with stringent levels for BOD, TSS, oil and grease, COD, total organic carbon, ammonia and phosphorus was obtained.

Solution: FujiClean USA treatment systems were specified. Due to complex topography, a combination of gravity sewer and two lift stations were utilized to deliver wastewater to a central collection point at the corner of the development. The combined final treatment system includes at 20,000-gallon trash/alum dosing primary treatment tank, a 20,000-gallon settling/equalization dosing tank, 12 FujiClean CE6KG secondary treatment units offering 72,000 gpd total capacity, a 1,500-gallon discharge tank and UV disinfection. The modular FujiClean treatment system allowed the developer to control cost and infrastructure during the build-out. A common operator building was constructed to house the UV, alum storage, flowmeter and control panels. 

Result: The FujiClean systems were successfully implemented in the subdivision. 207-406-2927; www.fujicleanusa.com

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ATU provides a low-maintenance solution and future growth opportunity

Problem: Geraldine, Alabama, needed a low-maintenance and expandable wastewater treatment system to treat all of its domestic waste to regulatory limits, allow for drip dispersal and handle flow fluctuations to retain consistent treatment ensuring no drip headworks clogging or excess dispersal field biomat development.

Solution: An ECOPOD Series ATU with a drip dispersal field from Infiltrator Water Technologies was selected for the 60,000 gpd system. The system reduces levels of nitrogen, BOD and TSS. It utilizes a stable and reliable fixed-film process to treat incoming wastewater from approximately 300 mg/L BOD/TSS loading down to the specified 30/30 effluent limit requirement. A STEP system at each home moves influent to the ECOPOD treatment system, which includes a flow equalization tank with duplex alternating pumps, four E1600 ECOPOD units installed in parallel, and a dosing chamber with duplex alternating pumps that provide controlled dispersal field dosing. Oxygen pumped into the system enables bacteria to thrive in greater numbers than would occur naturally speeding sewage breakdown for safe release into the environment. The entire intra-tank bioreactor treatment system is buried in a cast-in-place concrete tank, where both nitrification and denitrification occur.

Result: The system was designed with growth capabilities in mind. As the town expands, the easy, cost-effective addition of extra trains will keep wastewater treatment capacity in line with that growth. 800-221-4436; www.infiltratorwater.com

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Preserving infrastructure during remediation of restaurant treatment system

Problem: The McDonald’s restaurant in Chesaning, Michigan, utilized an ATU system followed by a sand filter and leach bed. After more than a decade of high-strength restaurant load, the leachfield and sand filter both failed.

Solution: SludgeHammer used the existing tanks. The modular bioreactor works in any type of tank, so clearing out the previous system components could give them a new lease on life. Sloan Septic conducted the renovation, pulling out the old equipment and rerouting some of the plumbing to create a sequential flow pattern.  Sloan installed six S-86 aerobic bacterial generators and seven supplemental Medusa air diffusers for extra digestion, given the heavy organic loads. A few repairs on the zone valves in the leachfield completed the project. 

Result: The system was restarted with an inoculation of SludgeHammer Blend facultative culture to see if biomat could be cleared out of the sand filter and leachfield. Some zone-switching allowed the system to work from day one, while the sand filter and rest of the field were biologically cleared. Now the system is fully functional and BOD testing showed an effluent strength of just 140 mg/L BOD, more than a 90% reduction. 231-348-5866; www.sludgehammer.net