Do you give a crap for science?

Do you give a crap for science? - Daniela Peguero

So, do you? I know I do. I am currently researching at the Pollution Research Group located at the University of Kwazulu-Natal in Durban, South Africa, where a team of us work with human poo. Yes, actual human waste. The idea of working with human waste remains a taboo topic today, but it’s one of the biggest global challenges the world is facing. In 2015, 2.4 billion people of the 7.3 billion people on Earth, lacked access to improved sanitation facilities, including 946 million people still practicing open defecation.

The two methods of handling human waste are on-site and off-site disposal methods. Local population density often decides which system will be more widely used. On-site systems store and can treat the waste in-situ and are typically used in less populated areas since they are easier and less expensive to manage at small scales. In the case of septic tanks, the waste needs to be transported, once storage is full, to a treatment facility. But how is it being transported, or more specifically, by who?

During my time in South Africa, I visited an informal settlement where workers were on-site disposing the accumulated waste from a ventilated improved pit (VIP) latrine. An informal settlement is an unplanned land settlement with improvised housing, as the land has not been proclaimed. For this reason there isn’t a sanitation infrastructure in place. Therefore, to encourage families to use VIP latrines and not practice open defecation, the Ethekwini Municipality Water and Sanitation disposes the contents from the latrines free of charge every 5 years. But where does this waste go? Unfortunately, the area is so densely populated, so to transport waste between the houses would be extremely difficult, as seen in Photo 4. It would’ve been really difficult to be able to navigate a truck in between those houses. The workers dug a hole right next to the VIP and disposed the contents there. Workers were wearing proper protection equipment as they worked to shovel human waste from the latrine. First the toilet needed to be removed in order to have access to the pit below and to remove the contents. It was very eye opening to see the people behind the scenes who are disposing the contents of the latrines. In the densely populated areas in the U.S., we are typically used to flushing the toilet without any thoughts as to where it may be going. Unfortunately, in rural areas and/or peri-urban areas around the world, a pour flush system just isn’t feasible. Varying options of pit latrines seem to be the most attainable. But once those systems reach full capacity, the waste needs to be disposed of and treated properly. As you can imagine the management of fecal waste isn’t the most glorious of jobs but it’s one of the most important. As population continues to increase, the management of fecal waste will remain a critical issue.

While I’m in South, Africa I will be assessing a treatment technology, named the Viscous Heater (VH) for fecal sludge. The sludge essentially passes through the technology and sanitizes the sludge. The sludge could then potentially be used for fertilizer application. However, the technology has been currently undergoing issues. Therefore, I’m currently waiting to see when it will be up and running, so I can begin my tests for microbial inactivation, once the sludge has passed through at a temperature of 60°C and 80°C.