Large-Scale and Commercial Treatment Systems

Large-Scale and Commercial Treatment Systems

Sequencing batch reactor solves village’s failing septic system problem

Problem: The village of Mifflin is a small community located in Ashland County, Ohio, upstream of Charles Mill Lake. The village’s home septic treatment systems were failing and causing water-quality problems in nearby waterways leading into the lake. As part of Ohio Environmental Protection Agency nutrient reduction efforts, a new wastewater treatment collection and treatment system was needed.  

Solution: The village hired an engineer who designed a gravity collections system with a lift station. The engineer evaluated several treatment options, eventually selecting a Sabre sequencing batch reactor from Earthtek Environmental. The system is designed to provide excellent effluent quality and is simple to operate. The plant also used buried fiberglass tanks, which are out of sight and minimize odors. This was a concern as the plant is located on the village’s main road and surrounded by homes. The plant included a buried 30,000-gallon, 10-foot-diameter, two-compartment primary treatment tank, a buried 30,000-gallon, 10-foot-diameter SBR tank for secondary treatment, mechanical tertiary filtration, ultraviolet disinfection, effluent flow monitoring and post aeration. Controls included a PLC with touch-screen operator interface, remote control and monitoring capability via the internet, and was installed inside a small building constructed on the site.

Result: The treated effluent has met the regulatory discharge permit limits of 10 mg/L BOD, 12 mg/L TSS, 1 mg/L ammonia and 126 colonies/100 ml E. coli since the startup period. 812-528-8784; www.packageplants.com.


Unit provides solution for convenience store chain

Problem: A mid-Atlantic convenience store chain had drainfield failure at close to all of its stores being served by onsite systems. Since initial permitting, they went from a traditional grab-and-go that offered handmade sandwiches to a full food service menu, introduced a line of 12 coffee decanters (that must be dumped every 4 hours), baking in-store bread, making smoothies, soft serve ice cream, milkshakes, all while disposing of substantially more disposable wipes, installing low-flow fixtures and moving from chlorine to quaternary ammonium for disinfection. The client was unwilling to change standard operating practices for stores with onsite systems, so the client needed systems to meet the needs.

Solution: Hoot Systems collaborated with the maintenance providers and engineers on developing modifications to dosing times of the equalization tank, automating the aeration system to vary carbon dioxide delivery based on wastewater strength and calibrating cycle times to ensure proper retention intervals in each stage of the treatment process. In addition, they stabilized alkalinity using pH boosters, added specific chemicals to the neutralize disinfectants and used carbon for the completion of the nitrogen-reduction cycle. 

Result:  With the redesign and operational modifications, Hoot Systems and the collaboration team brought these decentralized wastewater systems into compliance without changing the owner’s day-to-day standard operating procedures. 888-878-4668; www.hootsystems.com.


Treatment system effective against FOG

Problem: The historic Cottage Hotel in Mendon, New York, has been a popular spot since its opening in 1822. The 1/3-acre parcel presents major challenges for a septic system. Space at the site is mostly limited to the footprint of the buildings and parking. Wastewater is treated and discharged into a nearby stream. Pretreatment had historically been accomplished through an aerobic treatment unit with polishing through a single-pass sand filter.

Although the ATU and sand filter are good treatment technologies, fats, oils and greases generated from the kitchen waste were too much for the system to handle, causing the sand filter to clog routinely.

Solution: The owner hired Onsite Engineering to design a commercial septic system that could handle the high-strength restaurant wastewater and treat it to the high level needed for a permitted surface-water discharge. The redesigned system utilizes the White Knight MIG from Knight Treatment Systems. The unit inoculates and pretreats the wastewater with select bacteria that aggressively digest the FOG prior to passing through the rebuilt single-pass sand filter.

Result: The system installed in 2017 has been working well. 800-560-2454; www.knighttreatment.com.


Passive treatment unit used to replace failed system

Problem: A failed sand filter overboard discharge system on a shoreline needed to be replaced in Southport, Maine.

Solution: With the suggestion of the installer, the site evaluator decided on placing EnviroFin onsite treatment system from Presby Environmental Inc. (PEI) in the same location as the previous sand filter system, as the sand was of the quality needed for the EnviroFin system. The treatment system is 100 percent passive and treats the effluent better than NSF Standard 40 standards. The installation includes two EnviroFin units at 270 gpd.

Result: The customer has the benefits of a treatment system without the large expense, maintenance contracts or electricity. 800-473-5298; www.presbyeco.com. 



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