Solving the poo problem in South Africa

Miriam Mannak in AllAfrica.com: Access to toilets for Cape Town's growing urban poor is a regular flash-point, featuring angry demonstrations and hurled allegations by competing political factions. The city - and the Western Cape province in which it is located - are governed by members of the Democratic Alliance. Most of the South Africa's people live in areas governed by the ruling African National Congress, which won over 60 percent of the votes in recent national elections.

But whoever is in charge, South Africa shares a practical and political headache with urban areas around the world: providing sanitation to an influx of people, primarily from poor rural communities. "On current evidence," writes Richard Palmer in a blog post carried on the Future Cape Town website,  "it seems the truth of the matter is that providing basic sanitation services to South Africa's poor seems too big a challenge for our major cities, regardless of who governs them."

A report by the South African Human Rights Commission (SAHRC), published in March, doesn't leave much to the imagination. According to researchers, members of 1.4 million South African households don't have access to sanitation and are therefore forced to relieve themselves in the open. The bulk of them live in rural areas of KwaZulu-Natal, North West and the Eastern Cape.

Additionally, 26 percent of all South African households, 3.8 million in total, only have access to below-standard sanitation infrastructure. These facilities have crumbled and deteriorated to such extent that they can be considered unfit to be used....

A view of Soweto, shot by Medpro, Wikimedia Commons via Flickr, under the Creative Commons 2.0 license

Concrete-dissolving bacteria are destroying our sewers

Sarah Zhang in Gizmodo: Underground in places nobody likes to look, bacteria are doing terrible things to our sewage pipes. The concrete pipes that carry our waste are literally dissolving away, forcing engineers into a messy, expensive battle against tiny microbes.

“The veins of our cities are in serious trouble, and they’re in serious trouble because of corrosion, and this corrosion has been unanticipated and it’s accelerating,” said Mark Hernandez at a symposium on the microbiology of the built environment in Washington DC yesterday. Hernandez is a civil engineer, but he’s meeting with microbiologists because this problem is bacterial. Essentially, it’s an infection of the nation’s sewage system.

....One set of microbes emits hydrogen sulfide, the gas that is also responsible for raw sewage’s unpleasant smell. This gas fills the empty space between the top of the pipe and the water flow. Another set of microbes living in this headspace turns hydrogen sulfide to sulfuric acid, which eats away at concrete, leaving behind gypsum, the powdery stuff you find in drywall.

“Essentially what we’re ending up with is wet drywall,” said Hernandez. This is one reason the American Society of Civil Engineers has gave our wastewater infrastructure a D grade. The current solution is to put plastic liners into the concrete pipes, a process that is almost as expensive as digging them up entirely. But if the problem is microbial, perhaps the solution is, too?

...The solution they settled on was shotcrete — a type of concrete that can be sprayed onto the inside of pipes — embedded with small amounts of charcoal and bacteria-killing metals like chrome. As the acid ate through this concrete, metal would be released. Based on Hernandez’s tests, this concrete did hold up better against sewage microbes — suggesting a promising solution to corrosion....

Concrete sewer pipes, shot by TUBS, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic license

Powerful storm and power shortages fill Gaza with waste water

IRIN: Hamdi Al Shami, 54, woke up in the highly populated Zeitoun area of Gaza City, on 11 December, to find raw sewage flowing down his street at a height of more than 2m. It was just one of several sewage overflows to occur in his neighbourhood over the last five weeks.

On 13 November, more than 35,000 cubic metres of raw sewage overflowed when the Zeitoun pumping station failed, affecting 3,000 nearby residents. Just as the mess was being cleaned up, the area was again inundated - this time with approximately twice as much waste - when heavy rains fell over the Gaza Strip between 11 and 15 December. In Gaza City, one of the worst-hit areas, the municipality estimated that hundreds of thousands of cubic metres of sewage and rainwater overflowed from pumping stations and manholes, flooding streets and homes.

“It was horrible. We lost many things when the sewage came from everywhere around us - the doors, manholes and sinks. This cannot be forgotten,” said Al Shami, speaking about November’s flooding.

That flooding was attributed to a combination of factors: power outages disrupting the city’s sewage pumps and a shortage in capacity, spare parts and facilities because of a seven-year blockade against Gaza. At the time, residents were told that a rapidly established power connection to the Israeli grid would prevent future problems. But with the recent rainfall, the situation in Al Shami’s neighbourhood has only worsened. He was stranded amid water and sewage for days....

Destruction in Gaza after Israeli bombardment, part of Operation Pillar of Defense in November 2012, photo by Scott Bobb, Voice of America 

'Superbugs' found breeding in sewage plants

Terra Daily via SPX: Tests at two wastewater treatment plants in northern China revealed antibiotic-resistant bacteria were not only escaping purification but also breeding and spreading their dangerous cargo. Joint research by scientists from Rice, Nankai and Tianjin universities found "superbugs" carrying New Delhi Metallo-beta-lactamase (NDM-1), a multidrug-resistant gene first identified in India in 2010, in wastewater disinfected by chlorination.

They found significant levels of NDM-1 in the effluent released to the environment and even higher levels in dewatered sludge applied to soils. The study, led by Rice University environmental engineer Pedro Alvarez, appeared this month in the American Chemical Society journal Environmental Science and Technology Letters. "It's scary," Alvarez said.

"There's no antibiotic that can kill them. We only realized they exist just a little while ago when a Swedish man got infected in India, in New Delhi. Now, people are beginning to realize that more and more tourists trying to go to the upper waters of the Ganges River are getting these infections that cannot be treated. "We often think about sewage treatment plants as a way to protect us, to get rid of all of these disease-causing constituents in wastewater.

But it turns out these microbes are growing. They're eating sewage, so they proliferate. In one wastewater treatment plant, we had four to five of these superbugs coming out for every one that came in." Antibiotic-resistant bacteria have been raising alarms for years, particularly in hospital environments where public health officials fear they can be transferred from patient to patient and are very difficult to treat....

A white blood cell interacting with MRSA bacteria (an antibiotic resistant strain of staphylococcus aurea), National Institutes of Health

Recycled sewage water found safe for crop irrigation

Science 2.0: Low levels of pharmaceuticals and personal care products (PPCPs) were in crops irrigated with recycled sewage water, according to the first study conducted under realistic field conditions.   The research, which eases some concerns over using treated wastewater for agriculture, was launched because drought and water shortages in the American southwest and in other arid parts of the world are using water recycled from municipal sewage treatment plants to irrigate food crops as the only option.

Water from toilets and sinks enters those facilities from homes and offices, and undergoes processing to kill disease-causing microbes and remove other material. Processing leaves that water, or "effluent," from most sewage treatment plants clean enough to drink. Traditionally, however, sewage treatment plants simply discharge the water into rivers or streams.

The effluent still may contain traces of impurities, including the remains of ingredients in prescription drugs, anti-bacterial soaps, cosmetics, shampoos and other PPCPs that are flushed down toilets and drains so they wanted to know what levels remain.

"The levels of pharmaceuticals and personal care products that we found in food crops growing under real-world conditions were quite low and most likely do not pose any health concern," said Jay Gan, Ph.D., who led the study. "I think this is good news. These substances do not tend to accumulate in vegetables, including tomatoes and lettuce that people often eat raw. We can use that information to promote the use of this treated wastewater for irrigation."

Sprinkler irrigation, shot by Fir0002, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Ew! Hudson River bacteria linked to sewage

James M. O'Neill in NorthJersey.com: Researchers have found antibiotic-resistant strains of disease-causing bacteria living in some near-shore segments of the Hudson River from the Tappan Zee Bridge to lower Manhattan, largely connected with raw sewage dumped into the river.

The heaviest concentrations of these drug-resistant bacteria were found along the Hudson's shoreline near Piermont Pier in Rockland County and at Yonkers in Westchester County. They were also found on the Manhattan side of the river at 125th Street, as well as in Flushing Bay near La Guardia Airport and in Newtown Creek, which separates Brooklyn and Queens.

...The locations with heavy concentrations of the antibiotic-resistant bacteria also had high numbers of certain bacteria that indicate the presence of raw sewage in the water. Many older sewer systems combine sewage and storm water from streets, but during heavy rains cannot handle the added volume and dump raw sewage into the Hudson through combined sewer outfalls....

Aerial view of the George Washington Bridge over the Hudson, shot by Ajay Tallam, Wikimedai Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license