One way that we can make our existing water supply work more effectively
for our society is conservation. Through efficient use of fresh water supplies,
it is possible to stretch our existing resources further and preserve them for the
future. While there are many novel concepts and technologies that could make
a substantial impact toward conserving our water a challenge has been sharing
that information with the broader community of regulators, planners, contractors,
and appliance makers so that national policies might be developed. All of these
groups have a direct influence in implementing water conservation technologies
but lack of a common forum appeared to impede progress historically. In a proactive
move to change that trend, in 2006, the US EPA announced the formation of the
Alliance for Water Efficiency (AWE). AWE’s primary mission is to serve as an
advocate for water efficiency research, evaluation, and education by bringing
local, state and federal regulators together with utilities and industry
representatives to the same table.
Read on…..

When people talk about the major issues impeding progress in bringing clean
water and sanitation to the developing world, themes like “limited resources,”
“lack of infrastructure,” and “war” are common. All are certainly very real barriers,
yet one issue that stands in the way of millions having access to water rarely gets
attention: corruption.

Read on..

Most people have heard of acid rain, widely discussed as a threat to forests
downwind from coal-fired power plants. Acid rain is primarily caused by
sulfur dioxide (SO2), a byproduct of burning coal, oil or gas that is tinged with
sulfur. Because sulfur is a commonly occurring element, it is virtually impossible
to find deposits of these fossil fuels that do not contain sulfur. When sulfur dioxide
is emitted as these fuels are burned, it enters the atmosphere and reacts with
water. The outcome of this reaction is sulfuric acid (H2SO4); it is this acid that
gives the rain its name.

Continued

A great deal of recent media attention has been paid to phosphorus as a pollutant; this
article is intended as a primer on that topic. Specifically, this article will explore what phosphorus is, why it is used and how it enters the water system. Beyond that, the
problems created by excess phosphorus will be examined along with the constructive
ways that states and communities have dealt with the issues.
Continued

In the months and weeks leading up to the 2008 Olympic Games in Beijing, there
was considerable concern about the pollution in and around the Olympic venues
and its potential impact on the Games. Media coverage tended to focus on the
worst case scenarios of ‘what might happen’ but little coverage was aimed at what actions the Chinese initiated to mitigate health risks to athletes and spectators.
This article will shed some light on those actions and the results that followed. Continued……

In order to turn their design into reality, the lead students representing the American Society of Mechanical Engineers (ASME) open-source human powered water purifier design group met at Western Kentucky University over the weekend of May 16-18. The students came from as far away as Sweden and Venezuela but they each came with one intent: to build a water purifier that would function without supplemental electricity or battery power. Read on…

Over 500,000 tonnes of faeces are openly defecated every day to the environment around the world. That’s enough to fill the 30,000-seat Stade de Genève, where the Euro 2008 football tournament kicks off this weekend, three times over. But the global sanitation crisis is not a mere game: it pollutes the very environment upon which humans depend. Providing toilets and protecting the environment would be a winning combination for people and planet, says the Water Supply and Sanitation Collaborative Council (WSSCC).

“Each year, more than 200 million tonnes of human waste go uncollected and untreated around the world, fouling the environment and exposing millions of people to disease and squalor,” says Jon Lane, WSSCC Executive Director. “On World Environment Day, midway through the International Year of Sanitation, WSSCC is calling for governments, stakeholders and individuals around the world to accelerate the work to end these ongoing human and environmental catastrophes.”

Doing so, he says, requires neither colossal sums of money nor breakthrough scientific discoveries. Using existing, proven approaches and technologies, and for about US$ 10 billion a year – less than 1 percent of global military expenditure – the world could meet the Millennium Development Goal sanitation target to halve, by 2015, the proportion of people without sustainable access to basic sanitation. And around ten years later, everyone could have a toilet to use. “Achieving universal sanitation can, with proper financing, be accomplished through hard work on the ground, plain talk about toilets, strong leadership at all levels, and by creating demand for toilets among the 2.6 billion poor people who need them,” says Lane.

Toilets, washing facilities, garbage removal, wastewater disposal, stormwater drainage: sanitation services such as these are a prerequisite for clean, healthy household and community living environments, particularly in dense settlements. Such sanitation services are also vital to safeguard environmental quality more broadly, especially the quality of water resources. The cost is high, conversely, where sanitation services are lacking. Water pollution stemming from poor sanitation costs Southeast Asia more than US$ 2 billion per year, and in Indonesia and Vietnam creates environmental costs of more than US$ 200 million annually, primarily from the loss of productive land.

A healthy living environment depends on sanitary toilets
In teeming informal settlements across the globe, the sanitation crisis is keenly felt. With no way to safely dispose of either faeces or garbage, around a billion slum dwellers must resort to “flying toilets” (also known as “wrap and throw”) and to dumping trash in public spaces. This situation is not limited to urban settlements; in impoverished city suburbs, small market towns, large villages and periurban settlements across the developing world, the public environment is full of waste.

The contents of bucket-latrines and pits, even of sewers, are often emptied into the streets. A recent study of Indonesia, for example, found that roughly one in ten people are exposed to open sewers and the open dumping of solid waste, and more than four in ten to open defecation sites. Poor sanitation creates a host of health hazards as well as a bleak and disheartening visual landscape. Roads are full of mud, puddles, and piles of garbage and debris, not to mention disease-carrying insects, microbes and rodents. The odours are often unpleasant.

Imagine a community of 10,000 inhabitants, 30 percent of whom practice open defecation. Since each person produces 150 grams of faeces a day, open defecation would result in 450 kg daily or more than 3 tonnes a week – or 100 full dump trucks’ worth of human excrement annually – deposited in the community. Living in a squalid environment harms physical and psychological health; is stigmatising; often presents employment challenges; and deepens human poverty. A healthy living environment, one that supports human dignity and is free of disease-transmitting agents and conditions, is impossible without sanitation services.

Sanitary toilets aid environmental sustainability
Human waste enters water sources and land through open defecation, dumping of buckets, inadequate disposal via sewer pipes into water courses and onto unused land, and leakage from pit latrines. In the developing world, roughly 90 percent of sewage is discharged untreated into rivers, polluting waters and killing plants and fish. In Southeast Asia alone, 13 million tonnes of faeces are released to inland water sources each year, along with 122 million m3 of urine and 11 billion m3 of greywater. This presents a major health threat to people who depend upon open streams and wells for their drinking water as well as an economic blow to people whose livelihoods depend upon fisheries. Upstream water users find better quality water, whereas downstream users find “sewage sinks”. Water quality is worse near densely populated areas.

Reusing waste has many benefits
Sanitation involves a range of actions, but for a healthy environment – in communities as well as in the larger natural world – the top priority is separating excreta, with its host of biological pathogens, from contact with human beings as well as plant and animal life. In areas where it is practised, ending open defecation is a critical first step. But to fully realise the health, social, and economic benefits, the management of wastes must be considered. Conventional sewerage can now be supplemented with ecological sanitation technologies that make use of the nutrients in human waste. These range from simple “arbor-loos” (where a tree is planted on the latrine pit) to urine-diverting toilets that produce fertiliser from urine and safely composted faeces. Anaerobic digestion of sewage to produce biogas for energy is another option.

In China today, for example, 90 percent of human excreta is used in agriculture; the task is to make sure that raw sewage is not put on the fields. Chinese farming communities have proved open to the idea of urine-diverting, or “dry”, toilets that facilitate the re-use of excreta as fertiliser.

To support the awareness-raising effort on this and other key sanitation messages, the UN-Water Task Force on Sanitation has launched an advocacy and media kit in English, French and Spanish. Task Force Members include the United Nations Children’s Fund (UNICEF), World Health Organization (WHO), Water and Sanitation Programme (WSP), UNEP, United Nations Development Programme (UNDP), United Nations Human Settlements Programme (UN–HABITAT), United Nations University (UNU), and WSSCC.

World Environment Day, commemorated each year on 5 June and supported by the United Nations Environment Programme (UNEP), is one of the principal vehicles through which the United Nations stimulates worldwide awareness of the environment and enhances political attention and action.

The problem of water-born disease in the developing world is a serious one; each day over 6,000 people – most of them children – die from these illnesses. In fact, the world’s number one killer is diarrheal disease brought on by such bacteria as cholera, E. coli, salmonella and typhoid. Bringing safe drinking water to areas of the world that lack electricity has been a challenge but a Swiss company is hoping to change that. Vestergaard Frandsen has developed a low-cost, highly-effective personal water purifier called Lifestraw. Read on…

New technologies are tackling old problems in sewer repair; composite materials are being used more often today to deal with sewer repair and rehabilitation in major cities. These new materials offer interesting advantages over more traditional poured concrete structures or lined structures. Additionally, composite structures hold the promise of longer life, reduced installation costs as well as reduced inspection and maintenance costs.

Naturally-decomposing wastewater components will release hydrogen sulfide gas; if there exists space between the water level and the ceiling of the pipe or culvert, bacteria above the waterline will ingest the gas and secrete sulfuric acid. This highly corrosive acid will aggressively attack the non-submerged surfaces. If left undiscovered or unrepaired, this reaction will eventually decompose the concrete to the rebar. To prevent this situation, civil engineers have long relied on liners – some of which have even been composites. The downside of liners is that they are relatively thin and once they are damaged, they become ineffective. Composite pipe sections can address this issue by offering chemical resistance throughout the entire structure; in many cases, composite pipe sections can be used without a liner. By choosing resins that exhibit excellent chemical resistance, the pipe manufacturer can save a city or water district inspection and maintenance costs down the road.

Composite materials can also reduce repair costs. Cured-in-place-pipe (CIPP) solutions are emerging that use either fiberglass or stainless steel with cement grout. In many cases, where both ends of a pipe are accessible, CIPP requires no excavation – short links of sleeves are coupled together and pulled through the host pipe by a cable from one end to the other, creating a continuous stainless liner. Then a cement grout or polymer resin (depending on the technology) is pumped to fill the annular space between the host pipe and the liner. The grout (or resin) flows into all cracks and joints including the cracks of the host pipe, joining together the liner sections and all old pipe sections into a solid and unified structure.

Many firms that are promoting CIPP technology are quoting a 100 year life with specific resin or grout combinations; this has the potential to reduce maintenance costs as well as the hassles associated with repairs. Beyond the reduced long term costs, CIPP may also offer the benefits of reduced on-site crew size and the elimination of a digger or excavating crew, depending on the specifics of the situation.

A third technology that is being used is cast polymer concrete. As an almost direct replacement for traditional Portland cement, the polymer concrete is cast over steel reinforcing members and can achieve improved shear tensile, compressive and flexural properties compared to cementious materials. This technology was recent used in Charleston, South Carolina to create sewer interceptors that were critical in the city’s sewer rehabilitation plan.

The interceptor structures were approximately 10 feet in diameter and some were 100 feet deep. To build these, polymer concrete sections were produced off site that included integral steel connecting rings. These connecting rings secured each pipe section to the next; the base piece was cast with an integral composite floor. Because the materials exhibited through-thickness chemical resistance, there was no need to apply a protective liner; typically with pour-in place concrete, there is a cure period that must occur before any liner can be applied. Additionally, because the polymer concrete exhibited higher mechanical properties, the sections could be made with a reduced wall thickness compared to a design utilizing traditional materials; this allowed for a smaller crane to be used on site which was critical given the narrow streets of historic Charleston.

With an ever-increasing materials base from which today’s civil engineers and planners can draw, new opportunities for cost and maintenance savings are possible. By selecting the materials that make the most sense for each particular job these professionals are ensuring that our municipal and regional wastewater systems will stand the test of time.

Do you have a great idea on how to deliver clean water to disaster victims? If so, the American Society of Mechanical Engineers (ASME) needs your input. ASME recently put together an ‘open source’ community to design a human-powered water purification system. The goal of the project is straightforward; the team wants to develop a device that provides potable water without relying on an electrical hookup. Such a device has many potential uses ranging from use in the developing world to use after a disaster when utilities and sanitary services have been interrupted. More….