Reverse osmosis refers to a process of water purification that has been used primarily for the desalination of seawater. To understand reverse osmosis, it is first necessary to understand osmosis.

Osmosis is the term for the phenomenon whereby if a semi-permeable membrane separates two salt solutions of different concentration, water will migrate from the weaker solution through the membrane to the stronger solution, until the solutions are of the same salt concentration. Reverse osmosis subverts this process. Read more

The current major concerns in regard to water quality are lead and disinfection byproducts (Binnie et al, 2002). Lead is a key operational and treatment concern for municipal water treatment plants. It cannot be considered independently of other water quality and treatment issues.

In fact, it seems that water disinfection and protection from lead infiltration are at odds with each other. The pH level required for disinfection must be below 8.0, but the pH level required to minimize lead solvency in plumbing systems is often 8.0 or higher.

Water treatment plants provide clean, disinfected water to home plumbing systems, but this water is immediately contaminated from lead as it passes through the plumbing system. The solution to this problem may be the removal of lead from plumbing systems, a factor that would completely revolutionize the plumbing industry. Read more

In honor of World Water Day, the Columbia Water Center is releasing a video and two infographics about its work.

In “Deeper than Water”, director Gabe Askew evokes the preciousness of water through a the stunning images of jewels in an unfolding box, suggesting that if we are to truly care for our most valuable resource, we must go beyond digging to find the right crops and planting methods, design more intelligent infrastructure, prioritize ecology and invest in climate science.

India

No place in the world more clearly embodies the most challenging and diverse aspects of the global water crisis than India, the world second most populous nation. The story of water in India is on the one hand a distressing parable about good intentions and unintended consequences of a nation that averted famine by mining its groundwater–and on the other a story of hope, in which cooperation and bold thinking offers real hope for balance resource use and improving livelihoods.

“The Story of Water in India” outlines the food/water/energy crisis in India, and presents different solutions the Columbia Water Center is pursuing in the country. For more information about the Columbia Water Center’s work in India, check out our India project pages. Read more

Despite government regulations and incredible advancements in water technology, the water issuing from home taps is still quite contaminated. Although municipal water treatment plants are intended to provide clean, healthy water to all city residents, such plants must work with heavily contaminated water. The water contains disease-bearing pathogens, pesticide chemicals, and industrial sludge, to name only a few of modern water contaminants.

City officials must provide the healthiest water to municipal residents which modern technology affords. Considering the dirty water with which they have to work, this task can be quite daunting. Disinfection and disease control remain the main goals of such water treatment plants. Consequently, city residents receive chlorinated, and often fluoridated, water. Chlorine has been linked to asthma and other respiratory diseases, and excessive fluoride intake can lead to yellowed teeth, dental problems, and other serious health problems for young children. Read more

Recent studies by the United States Government Accountability Office and the Environmental Protection Agency found numerous instances of pharmaceuticals in drinking water. According to the GAO, a “study focused on untreated source water used by public drinking water systems” found that 53 of 74 sites tested had at least one pharmaceutical present, and in 2010 the EPA showed that 54 active pharmaceutical ingredients and 10 metabolites, the product of biological changes to a chemical, had been found in treated drinking water.

Pharmaceuticals can enter the water supply in a variety of ways. Debates continue over how dangerous this is. Source: GAO

An earlier study from 2005 by the EPA and the Geographical Survey states that 40% of water was contaminated with nonprescription pharmaceuticals, and it has been reported that of the 8 of the 12 most commonly occurring chemicals in drinking water are estrogenic hormones. Read more