Monthly Archives: October 2014

Rainwater Catchment

Millions of People Have No Access to Clean Drinking Water

earth with water dropletThroughout the world, more than 780 million people have no access to clean drinking water.

Here in the United States, we use filtered, disinfected water to flush our toilets, water our lawns, and wash our cars. For most NGOs, the focus for clean drinking water is shallow water wells. The problem, in many regions of the world, is that naturally occurring arsenic is found in these wells; arsenic is harmful to bone development. While fluorides are added in trace amounts to most public water supplies in America, high levels of fluorides can be found in shallow water wells throughout the globe and can cause dental decay. However, the most common threat to drinking water globally is cholera. According to the World Wide Health Organization, there are 3 to 5 million cholera cases with 100,000 to 120,000 deaths per year. It is considered to be endemic in many countries.

Ken Blair in Sierra Leone, AfricaSimple techniques of rainwater collection and natural solar water disinfection can saves lives in developing countries. Rainwater collected from the roof and screened before storage comes in no contact with sewer materials or human feces, leaving only bacterial contaminants to be disinfected. This can be achieved as simply as filling a 1 litter, clear bottle with rainwater and leaving it in direct sunlight for approximately 4 hours or 8 hours in overcast conditions.

RainBank’s president is a founding director of Bank on Rain and traveled to Sierra Leone in 2012 and 2013 to teach rainwater catchment and solar disinfection.

Rainwater Catchment, Residential Rainwater Collection

Rainwater Collection for Potable Use in an Urban Environment

seattle-skylineSupplementary whole-house use of rainwater in an urban environment is more complex than collecting for potable use in a rural environment. In a rural environment, there is typically more room for storage, allowing the homeowner to store more water than that in an urban setting.

The larger question, however, is – what is landing on my roof and how do I know my collected water will be safe to drink?

In a rural setting, organics are what you need to filter out before the water is to be disinfected and considered potable. A sediment filter, followed by a carbon filter prior to ultraviolet disinfection can achieve this. Bird droppings are the primary concern in this situation.

In an urban environment, other constituents coming in contact with your roof may need to be addressed. Consider where your home is located. Environmental considerations such as automobile and truck emissions can have an impact on your roof runoff and must be removed with proper filtration. Pesticide use is more likely to be encountered in an urban setting than a rural environment. Simple sampling and laboratory testing should be conducted of raw water so proper filtration can be used to eliminate possible contaminants.

Urban potable usage of roof top collected water can be achieved with the proper filtration as with any rural potable system as long as the right filtration is used.

Photo: Julie Gentry

Rainwater Catchment

How Much is Water (Conservation) Worth?

How Much is Water WorthHow much is water worth?

The question in itself is a huge discussion among corporate leaders and governmental agencies throughout the world. With increased demands of growing populations, droughts which plague many regions globally, and the lack of conservation, many are asking “how do we protect a common resource throughout the world, while providing a necessity of life for all of its inhabitants?” According to the UN’s Intergovernmental Panel on Climate Change “We have a genuine, burgeoning, boundary – crossing crisis over water.” PepsiCo. CEO Indra Nooyi says “The world water crisis is one of the most pressing challenges of our age.”

Companies are concerned as farmland suffers and the demand for water mounts. What is the solution? According to Fortune Magazine, “Some say: make people pay more for the most precious commodity on earth. “When water has no value, even low cost technology will never get implemented on a large scale.”  Furthermore, the article deems that water is so inexpensive that there is no incentive for conservation. Water needed for drinking, cooking, farming and basic life supporting necessities needs to be available to all, while there should be limits on non-essential use of water with cost increases to offset conservation practices and technologies.

The city of San Diego, which has experienced a drought not seen before in our lifetime, is investing money in large scale desalinization systems, paid for, in part, by a tiered water pricing system. While many think this to be controversial, the need is there, without some sort of rethinking how we manage our water supplies, there will be little water to manage.

While rainwater collection is not going to be the final answer to water conservation, it certainly is a simple step that can be adopted relatively inexpensively, and with positive results on a small scale. Think about the money that can be saved by our municipal water districts which can then be redirected to other methods of supplying water. If the city of San Diego, as well as other cities, would realize the value of water and encourage rainwater collection on a larger scale, we could conserve over half the amount of water being wasted for non-essential use.