Case Studies - March 2020

Mar 10, 2020 | by Craig Mandli |

Sequencing batch reactor a fit for island resort

Problem: An island resort in the Florida Keys was having trouble meeting discharge limits with its 18,000-gpd extended air package treatment plant. The owner engaged Morris Smith Engineering to evaluate options for rehabilitating or replacing the plant. To make matters worse, after the engineer’s initial inspection the resort was hit directly by Hurricane Irma, causing great damage to the resort and plant.

Solution: The decision was made to rebuild the resort and replace the plant. The Sabre sequencing batch reactor from Earthtek Environmental was selected due to its treatment specifications, minimal operations and maintenance requirements, and reduced waste sludge. The system is installed in fiberglass tanks, which would not corrode in the island’s saltwater environment. The tanks are also lightweight and were easily delivered to the island by barge. The tanks were placed on the ground and surrounded by retaining walls and sand backfill to raise them above flood level. The system is a fill-and-draw process, which treats wastewater in batches. It includes a primary tank where solids are settled out and scum floats. Duplex pumps transfer the effluent to the SBR in batches where it is aerobically treated and BOD, TSS and ammonia are reduced. Chemical treatment also reduces phosphorus in the final effluent. Treated effluent is filtered by pressure filters with Zeolite media and disinfected by UV units prior to discharge to soil disposal and deep well injection.

Result: The system has performed as advertised. 812-528-8784; www.packageplants.com.

Sand filtration system a fit for property with shallow water table

Problem: A real estate flipper in North Smithfield, Rhode Island, needed to replace a cesspool for a two-bedroom home so the property would pass a time-of-sale inspection. The property had a shallow water table, and all setbacks had to be met for a code-compliant system. The builder wanted to make sure a system would be able to be installed below grade, as to not detract from the curb appeal.

Solution: D.H. Keene Septic designed the system and chose Eljen GSF (Geotextile Sand Filter) B43 modules for the drainfield because of the reduction in footprint size and shallow profile compared to a traditional system. The 80-foot-long by 4-foot-wide trench was placed within the setbacks of the property line and well by Matt Osborne and Dan Marcotte from Ken’s Excavating. A tipping distribution box delivers effluent to the 18 GSF modules from new 1,000-gallon septic tank.

Result: The home has a code-compliant system that was installed quickly so the property could be sold. The GSF system was installed in a smaller footprint than a stone-and-pipe system but requires the same maintenance. 800-444-1359; www.eljen.com.