Water storage tanks

I am completing a unique small masonry project.  This is to be a sub-surface water storage tank, made from triangular manufactured concrete block.  I will be using it as a “plunging tank” to cool off after taking a sauna.

This simple prototype uses an early version of the triangular block system described on this blog (here, here and here).  The blocks used for this tank do not utilize the interlocking key and keyway system.  I was just using up some of my older block.

This tank assembled quite easily.  It is incredibly strong, and is expected to last a very long time.  It will be filled with rainwater, as a proof-of-concept for a rainwater harvesting system.  Rain will be collected from the roof of the sauna (not yet built).  Water will be refreshed and kept from stagnating by simple replenishment from fresh precipitation.

Mortar was used in this model, although this system can also be assembled as a dry-stacked sphere.  Dry-stacking is especially easy with the key and keyway system, as described here.  A dry-stacked tank would require a bladder, or parge coat and sealant.

The use of mortar allows for the shape of the tank to be modified, if so desired.  Mortar can be applied in thicker or thinner amounts to vary the shape of the tank.  In this case, I made the sphere deeper, or elongated it almost like an egg.  This was to provide a deeper tank, for easy submersion.  It is around 8 feet deep.

I cast a pipe under the tank, so that I can run electrical wires, leading to a waterproof underwater light, at the bottom center of the tank.  This will be powered by a solar panel on the small roof of the tank.  I’m hoping it will provide an illuminated fishbowl effect.

I plan to coat the inside of the tank with inexpensive pool paint, since people will be “swimming” in it. 

The top of the tank will have a “wishing well” type roof on it.  It is important to shield the tank from sunlight, since this will encourage algae to grow.  There will also be a hinged lid on the tank to keep insects out.

I am hoping to be able to use this tank without chemicals such as chlorine or bromine.  I’ve installed a pump for circulation, as a back-up in case rain is infrequent.  This will help keep the water from stagnating, and will keep it somewhat oxygenated.

I plan to build another sphere soon, much like the water storage tank.  This other tank will be used as part of a septic system.  These tanks are inexpensive, very strong, high volume (around 1,500 gallons) and easy to install.  I will post my efforts on this blog as things move forward.

To see the tank completed, please look here.

Galileo's Thirst for Knowledge: Priceless. Quenched: $470 Billion.

Over the past three entries I wrote about Galileo’s mistaken approach toward analyzing masonry domes and arches, where he invoked his Square Cube Law to wrongfully criticize the work of ancient master masons. One of the insights gained from a proper and correct stress analysis, which involves thrust force lines describing a catenary curve within the thickness of an arch wall, is that extra weight, or loading, applied to the outside of an arch actually makes the arch stronger by keeping the thrust force lines closer to the center of the arch wall.

The implications of this correct structural analysis are far-reaching and insightful, for numerous applications of masonry structures: some of which I have already been discussing in this blog.

If a complete sphere is assembled, and this complete sphere is submerged below water, the water applies a load to the outside of the sphere. Water pushes in on the round sphere fairly equally, all the way around the sphere from all directions. This external loading keeps the thrust line forces equally distributed around the entire sphere, and it keeps these thrust line forces located in the center of the wall thickness, resulting in an optimal loading of compressive forces. Any other shape, whether it is a cube, rectangular, elliptical, etc., will not distribute this external loading in an equal, symmetrical manner as a sphere does.

This attribute of a masonry sphere subject to external compressive forces bearing such loading equally and symmetrically about its surface means that a below ground storage tank, built as a sphere, is an ideal configuration for any below ground tank. If a below ground tank is used to store water, then the weight of the water will apply an interior force, or head pressure, against the inside of the sphere, so that this force weakens the sphere and must be countered by an external force. Given that the density of water is 1.0 grams/cubic cm, and that average soils have a density of around between 2 and 3 g/cc, it is obvious that the external forces of the surrounding soil are 2 or 3 times the internal pressure of the water held in the tank. In other words, there is substantially greater compressive force acting on the outside of the sphere from the surrounding soil than there is acting on the inside of the tank by the water stored there.

These examples further illustrate that a masonry sphere used as either a below-ground water storage tank or as a means of desalination, as discussed here and there in this blog, are ideal solutions to the growing global problem of potable water use, storage and procurement. This water problem can be addressed by the existing manufacturing capability of the concrete block industry, using its existing methods, materials, and infrastructure. This can be done in an economical, sustainable and easily implemented manner.

This represents a huge market, and the proposed technology could be a big part of the answer to a pressing problem which is expected to worsen with climate change and the growing needs of humanity. Currently, the size of the market for potable water is estimated at $470 billion. One in eight people around the globe lack access to fresh water; that’s almost one billion people. The solution described here could help address this problem.

To see a completed prototype for water storage, please look here.

Masonry to help Women and Girls around the Globe

I am applying for a grant through the State Department and the Rockefeller Foundation, in an effort to help women and girls in developing countries around the globe.  This effort is described at this link.

They are just asking for a short (5 page) summary of the idea; if it is deemed worthy, they will then ask for a full proposal.  Funding is available up to $500,000.

Here is my paper describing this effort:
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Potable Water and Sanitation System to Improve the Lives of Women and Girls on a Global Scale


-Concept Paper-

1. Primary Problems Addressed

Water Storage Women and girls in developing countries around the globe often face a daily struggle to procure, store and use safe drinking water for themselves and their families. Across different cultures, geographical boundaries, and religions, this critical responsibility typically falls on women and girls. The importance of access to potable water for the well being of humans cannot be overemphasized. A huge amount of time, energy and resources is consumed in the daily quest for potable water. This onerous burden prevents women and girls from using their time and resources for other critical aspects of living. This situation results in a continuous cycle of poverty, poor health, and lack of security for women, girls and their families. This problem is only expected to worsen as the effects of climate change continue to adversely affect the supply and access to clean water globally.

Sanitation The problem of safe, affordable, reliable access to potable water is compounded by unsanitary conditions and is often due to improper methods of disposal and treatment of human waste in close proximity to water sources. Contamination of water sources with microbes and parasites from human waste creates major public health problems on a global scale. The burden of dealing with dysentery, diarrhea, sickness, and death falls disproportionately on women and girls within the family unit.

Procuring Fresh Water Our changing climate is reducing the sources and availability of fresh, clean potable water across the globe. As glaciers melt, they have become less reliable as the traditional source of potable water for many areas dependent on this source of water. As sea levels rise from climate change, salt water and brackish water encroach on fresh water aquifers, further reducing the availability of fresh water for human consumption. The most vulnerable populations to the lack of fresh water are those already plagued by the deepest poverty, poor health and lack of fundamental security resulting from poor access to water and food. Women and girls feel the effects of diminishing sources of fresh water most acutely, since they are traditionally relied upon to provide their families with water.

2. Description of the Innovation

The innovation proposed to address these three problems (water storage, sanitation, and procuring fresh water) is an innovative masonry system comprised of triangular interlocking concrete blocks which assemble into a sphere. These masonry units are manufactured on a concrete block machine which produces high strength, low cost, consistently reliable masonry units. The concrete block industry has a strong presence around the globe, and has the resources and ability to produce these masonry units using existing methods and materials. All that is required is a set of molds for producing these innovative blocks.

Water Storage Storage of potable water is achieved through an underground spherical tank. This tank is assembled by hand, requiring no special equipment or skills. Blocks are to be provided by a block manufacturer. These triangular blocks are easy to assemble and create a very high strength concrete sphere which can be expected to last on the order of one hundred years or more. These tanks would be of a size that is obtainable by individual families and households.

Sanitation The problem of proper disposal of human waste is addressed by use of a septic tank system. The septic tank is also an underground sphere made of the same triangular block as required by the water storage tanks. This system isolates human waste from potable water, creates a much cleaner environment, and ultimately produces rich fertilizer for use in growing crops in an economical and sustainable fashion. The liability of human waste is converted into a valuable asset for producing food.



Procuring Fresh Water Fresh water is currently produced around the globe by desalination of salt water. Two basic methods are currently used for desalination: distillation and reverse osmosis filtration. Both of these methods require a significant amount of energy and are expensive. Distillation requires a lot of heat to boil or evaporate fresh water from salt water; reverse osmosis requires a lot of electrical energy to achieve the high pressures (~1,000 psi) necessary to force salt water through a semi-permeable membrane which removes the salt component. Spheres made from the masonry system described here have a very high compressive strength (~8,000 psi). These spheres can be outfitted with an inexpensive surrounding membrane and a portal which contains a reverse osmosis filter. If the sphere is sunk to a depth of 2,225 feet below sea level, the pressure exceeds 1,000 psi and salt water is forced through the membrane, filling the sphere with fresh water. The sphere is then floated to the surface using an inflatable bladder, so that no energy is required to pump fresh water to the surface. The fresh water is then harvested, the sphere is re-sunk and the process repeated. A large scale operation of this type (involving hundreds or thousands of spheres) would achieve an economy of scale, and does not require the high energy and cost of conventional desalination methods. The cost of these spheres would be relatively inexpensive.

The innovation proposed here could help solve the three critical problems of water storage, sanitation and procuring fresh water. This can be done inexpensively, at any location around the globe, using existing methods, materials and equipment currently in use by the concrete block industry. The effect of this innovation on women, girls and their families would be far-reaching, dramatic, sustainable, affordable and environmentally appropriate.

3. Stage of Development

This innovation has been in operation for over 5 years, although the application of this innovation for the purposes described here have been in operation for less than one year. This masonry system has been used for architectural applications, to build kilns and furnaces, and for landscaping applications. These innovative blocks have been successfully produced on commercial concrete block machines, and buildings have been constructed using this masonry system.

4. Specific Activities

This technology has been patented, manufactured and introduced to the concrete industry in the US. This innovation was identified as a “Cutting Edge Technology” by the American Concrete Institute (ACI) the trade group for the industry; which establishes building code and works to advance the state-of-the-art in concrete technology. Several buildings have been successfully constructed using this masonry system, and various landscaping features have been assembled and installed using this novel masonry system. This technology has also been used to build high efficiency kilns and furnaces under two grants awarded by the New York State Energy Resource & Development Authority (NYSERDA). Currently, a new business (Sure Well, LLC) is working to introduce this masonry system for water storage applications in the state of Utah. Utah State Bill 32 was recently signed into law, which allows citizens (for the first time) to store and use rainwater in Utah, in below ground tanks of up to 2,500 gallons. Sure Well, LLC is able to provide these tanks at a fraction of the cost of other below ground water storage tank companies. This company is expecting to expand its operations on a national level, providing this high performance, inexpensive water storage solution across the country through a number of concrete block manufacturers. Currently, the principals are working with Besser Block Company, a global leader in concrete block production, to make this masonry system available on a global basis. Besser has a strong presence in 115 countries around the globe and is a leading producer and provider to the concrete block industry on a global scale. This innovation has not yet been employed for the specific applications described here, thus no metric is currently available for improving the lives of women and girls for whom these applications are intended to benefit.

5. Sustaining the Innovation

To date, this innovation has been sustained through private investment, grants, collaboration of industry & trade organizations and a boot-strap effort.

6. Expected Results

The results of award funding are expected to be immediate and far-reaching. Molds for this masonry system will be purchased and distributed to those locations which have the greatest need. Block will be manufactured and an educational effort will be launched in conjunction with the manufacturers, government agencies, NGO’s, and other philanthropic organizations to help ensure the distribution, proper installation, assembly and use of this system for the three applications described here (water storage, sanitation and water procurement). Water storage and sanitation can be implemented immediately. Water procurement through desalination will require further testing, development and trials. Desalination is expected to be developed within three years; once developed it can be rapidly deployed to any number of locations. This system relies on the existing, developed and tried and true methods of the concrete block industry.

Measurement of project success will be readily obtained by simply counting the number of people and households directly benefitting from clean water storage systems, septic systems and access to clean potable water. A typical fully mechanized block machine is capable of producing over 3,000 blocks per hour. Each concrete sphere requires 180 blocks. A block machine in continuous operation is thus capable of producing enough blocks to make 400 spherical tanks per day. Molds can be re-fitted with new wear parts at a low cost, and used on another machine in a different location, dramatically maximizing the high-efficiency production of state-of-the-art concrete block production on a truly global basis. The ability to free women and girls from the onerous task of providing fresh water and sanitary conditions will have a huge and immediate benefit.

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I am sure we could help a lot of people with this project.  Let's hope others think so.

Retaining Walls: to make a glacier?

I just came across an interesting article in Scientific American, which describes one man’s successful effort in using retaining walls to create artificial glaciers. I thought this was quite interesting, and since I just wrote about retaining walls, figured I’d share this.

Chewang Norphel is a retired engineer who has been working with the village of Stakmo in the Himalayas. Global warming has been reducing the glaciers in the Himalayas, and many villages are entirely dependent on water which results from glacial run-off in order to live, farm, and raise livestock.

Norphel uses masonry retaining walls to divert, capture and store run-off in a sort of reservoir; so that it freezes and forms a glacier. Subsequently, the “glacier” undergoes a natural but controlled melt, and provides run-off for the needs of the villagers.

This is a fine example of appropriate technology being used. Note that all the masonry is simple stone, found on-site. A very successful, attractive and effective system which looks like it should last for a long time with simple and modest upkeep.

Here's a great slideshow about Norphel's effort.

Masonry used for water storage will likely have a growing role globally as the need, cost and scarcity of potable water increase.