In College County, sand with an effective size of 0.9 mm and a uniformity coefficient of 3.5 is available from a local aggregate company at a reasonable cost. Propose an intermittent, buried sand bioreactor for an individual three bedroom home that uses the locally available sand.
| Design wastewater flow | Bioreactor depth | Exposure | Recirculation | Dosing frequency |
| 3 bedrooms* 120 gals. = 360 gal. | 2 ft. | Buried | No | 12 times/day |
| Sand Characteristics | Loading Rate | Size | Management | Discharge |
|
ES = 0.9 mm UC = 3.5 |
0.5 gal/ft2/day | 15 ft. x 50 ft. | Pump septic tank, service pump and chlorinator, check for ponding | On-lot irrigation |
A community library needs a wastewater treatment system to replace an old, failed soil absorption system. Much of the land owned by the library has been paved for parking. The paving even covered up the old septic system that likely contributed to its failure. Only a 15 x 25 ft. area is available for a wastewater treatment system and a nearby stream could be considered for a discharge. Propose a sand bioreactor to fit in this small space.
| Design wastewater flow | Bioreactor depth | Exposure | Recirculation | Dosing frequency |
| 6 FTE employees * 45 gals./employee = 270 gal. | 2 ft. | Covered | Yes | 24 times/day |
| Sand Characteristics | Loading Rate | Size | Management | Discharge |
|
ES = 0.3 mm UC = 2.5 |
3 gal/ft2/day | 2 reactors each 5 ft. x 10 ft. | Pump septic tank, service pump and chlorinator, check for ponding | Stream discharge with NPDES permit |
A developer is planning an executive housing development for 25 homes. An elaborate landscaped entrance and roadway is planned and wastewater is being considered for irrigation. Appearance, odors, noise, and space are all limitations. Propose a sand bioreactor system for this community with the aesthetic considerations in mind.
| Design wastewater flow | Bioreactor depth | Exposure | Recirculation | Dosing frequency |
| 25 homes * 5 bedrooms* 120 gals./bedroom = 15,000 gal. | 2 ft. | Covered | Yes | 48 times/day |
| Sand Characteristics | Loading Rate | Size | Management | Discharge |
|
ES = 1.2 mm UC = 3 |
3 gal/ft2/day | 2 reactors each 50 ft. x 50 ft. | Pump septic tank, service pump and chlorinator, check for ponding, flush irrigation lines | Trickle irrigation system |