Agriculture is historically linked with human derived fertilizers. For centuries, farmers replaced the organic matter and nutrients, removed from the soil through harvested crops, with human excreta.
Productive sanitation is a paradigm shift from our current practice of disposal based sanitation that treats our waste as quickly as possible and sends it on its way. Productive sanitation recognizes this waste as valuable resource streams that can be captured and treated to provide a safe and natural fertilizer.
Human urine and feces (composted feces are usually referred to as humanure) are being used in many parts of the world to aid farmers in meeting their crops’ nutrient demands. In doing so, farmers benefit from the nutrients, and the community benefits from the reduced impact on the environment.
BENEFITS TO AGRICULTURE
BENEFITS TO THE ENVIRONMENT
Reduce Dependence on Synthetic Nitrogen Fertilizer
- It can take 1.5 tons of fuel to make 1 ton of synthetic nitrogen fertilizer
- When coal- and natural gas–fed plants produce ammonia, they generate two main by-products: heat and carbon dioxide (CO2). Even high-efficiency ammonia plants are heavy CO2 emitters: two tons are released for every ton of ammonia produced.
Alleviate Dependence on Finite Phosphorus Reserves
- The World Health Organization, amongst other institutions, predicts that phosphate carrying rocks/mineral reserves will run out in 60-130 years.
- At the moment, the depletion of phosphorus reserves is less of a concern than the decrease in their quality (and therefore increase in price) and the strategic considerations of the world’s phosphorus producers. If no new sources of high quality phosphate are identified, future phosphorus reserves will contain less phosphate and higher levels of enrichment by heavy metals, principally cadmium.
- Urine alone contains more than the 50% of phosphorus excreted by humans. Thus the diversion of urine and its use in agriculture can aid in crop production and reduce the need for costly advanced wastewater treatment methods to remove phosphorus from the effluents.
- Around 80% of the nutrient nitrogen and 50% of the nutrient phosphorus in wastewater come from human urine. Rather than allow these nutrients to be released into the waterways, or use energy intensive methods to remove them at wastewater treatment facilities, it would be preferable to make use of them in crop production. Applied at the appropriate time, the majority of the nutrients can be utilized by the plant.
- Wastewater discharge currently contains pharmaceuticals. Capturing and treating source separated urine upstream will reduce the impact of these toxins on our waterways.