Composting Toilets By: Joe Luthman and Brian Prenger

How it works Instead of flushing, the waste drops down a pipe to the composter, which is hidden from view with a trap door or screen Aerobic bacteria within the waste break it down with the help of air, heat and time. The material needs stirred regularly, and materials such as sawdust need to be added to keep the bacteria working

Different Design Options Self contained system –Change yourself –Air vent –Emergency drain is added for times of heavy usage –Using no electric and no water

Different Design Options Central Flush System –Has a holding tank –Fan and air vent –Uses electricity for fan –Uses 1 pint of water per flush

Different Design Options Central Dry System –Largest system –Can be used by up to 9 adults –Larger evaporation area –Uses electricity for fan and heater –Uses no water

What is “green” about a composting toilet? Reduce – Composting toilets use less water than standard toilets and reduce the amount of waste sent to wastewater treatment plants Reuse – Reuses waste as a fertilizer for plants Recycle – Composting toilets recycle waste

Manufacturing and Shipping Envirolet –Manufactures compost toilets throughout North America UPS uses carbon neutral shipping –Purchases carbon credits to offset carbon footprint –Will match all carbon neutral shipping orders for 2010 up to $1 million

What is not “green” about a composting toilet Maintenance –Need to be properly maintained or they could create a biohazard Health Issues –Using inadequately treated humus as a soil may have possible health consequences Energy Use –Most composting toilet systems require a power source for a fan to keep the system at 65° F (about 120 watt-hours per day)

EIO-LCA Manufacturing Sector GWPCO2 FossilCO2 ProcessCH4N2O MTCO2E Other major household appliance manufacturing HFC/PFCsTotal EnergyCoalNatGasPetrolBio/Waste MTCO2E TJ NonFossElecCarcinogensNon-carcinogensRespiratory inorganicsOzone DepRespiratory organics TJ Mg C2H3Cl eq kg PM2.5 eq kg CFC-11 eq kg C2H4 eq Aquatic ecotoxicityTerrestrial ecotoxicityTerrestrial acid/nutriAquatic acidifAquatic eutroWater Use Gg TEG water Gg TEG soil kg SO2 eq kg PO4 P-lim kGal Cost = Roughly $1500

Is this product really green? We feel that this project is green While it does still use electricity, the electricity used to power the product could come from an environmentally safe source The composting toilets could become more efficient in the future