- alternatives - anaerobic digestion: enclosed, produces methane biogas and nutrient-rich liquid(digestate), more compact than anaerobic, less labor - Thermophilic Composting: (131-150°F) aerobic, better pathogen reduction, faster than normal composting - Living Machine/Constructed Wetland: https://theecologist.org/2010/jun/08/living-machine-ecological-approach-poo - septic - Small-Scale Treatment Plant - Holland system heats water to 95°F to melt ~1 inch of snow per hour at 20°F with 10 mph winds | Solution | Initial Cost | Annual Cost ($/Labor) | Capacity (1000 person) | Pros | Cons | | ----------------------- | ------------ | ---------------------------------------------------------------- | ------------------------------ | ---------------------------------------------------------------------- | --------------------------------------------------------------------- | | Treatment Plant | $1,000,000+ | $90,000/yr<br>2000 hrs/yr<br>($50k maintenance + $40k amortized) | 50,000 gal/day | - Highly controlled<br>- Meets all regulations<br>- Handles peak loads | - Very expensive<br>- High energy use<br>- Requires experts | | Centralized Septic | $600,000 | $40,000/yr<br>200 hrs/yr<br>($20k maintenance + $20k amortized) | 40,000 gal/day | - Simple operation<br>- Low maintenance<br>- Familiar technology | - No resource recovery<br>- 2+ acres drainfield<br>- Groundwater risk | | Living Machine | $500,000 | $35,000/yr<br>500 hrs/yr<br>($15k maintenance + $20k amortized) | 35,000 gal/day | - Water reuse<br>- Educational value<br>- Produces clean water | - Climate sensitive<br>- Complex biology<br>- 1+ acre footprint | | Anaerobic Digester | $400,000 | $41,000/yr<br>800 hrs/yr<br>($25k maintenance + $16k amortized) | 2,000 lbs/day + biogas | - Energy production<br>- Compact system<br>- All-weather operation | - Technical complexity<br>- Startup issues<br>- Skilled operation | | Hybrid Compost/Digester | $350,000 | $34,000/yr<br>1200 hrs/yr<br>($20k maintenance + $14k amortized) | 1,800 lbs/day + partial biogas | - Flexible operation<br>- Multiple outputs<br>- System redundancy | - Complex management<br>- Higher maintenance<br>- 0.5 acre footprint | | Distributed Composting | $200,000 | $18,000/yr<br>1040 hrs/yr<br>($10k maintenance + $8k amortized) | 1,200 lbs/day solid waste | - Resource recovery<br>- Low water use<br>- Simple technology | - Daily collection<br>- User maintenance<br>- Public acceptance |