Inclusions (at end of article) Copyright National Atlas Of The United States:
Fig. 1 - U.S. Aquifer Map
Fig. 2 - U.S. Aquifer Map with main river waterways
Fig. 3 - U.S. Aquifer Map with examples of shunt interconnections (in black)
This white paper explores a possible and practical method to reinvigorate the global fresh water supply by directly recharging existing natural, underground water aquifers with fresh water derived from sea water directly above them. In this way, we can replenish diminishing fresh water supplies at their source. This method allows the continued, unmodified use of all extant distribution systems currently connected to the existing subterranean aquifers which service populated areas.
With this system, fresh water is distilled or otherwise generated at sea, directly above target coastal aquifers into which it is injected. These pre-existing, under-sea aquifers are either originally, geologically connected or can be artificially connected to aquifers under the adjacent continental landmass upon which human populations dwell. This system obviates the need for new or additional large quantity, long-haul transport of fresh water (pipeline, rail, road) from wilderness or otherwise out-lying areas to populated areas.
This paper also will demonstrate that this method can be energy efficient and environmentally responsible and will illustrate how such a process could be undertaken using technologies already in existence and therefore can be applied with a reasonable expenditure in research and development and within a concise timeframe.
While this paper is focused on one solution in which I see great hope, I also would like it to serve as an invitation and inspiration to the scientific and lay communities to further collaborate to expand practical solutions. The ideas that will propel and sustain us into the future must be bigger in scope, bolder in concept and at the same time, actually work within practical timeframes as we no longer have the luxury of imagined immortality.
What is our timeframe for this project? I wish I knew but for now, I set a goal of demonstrating this process for significant, quantifiable, new fresh water acquisition and distribution, demonstrated on a world-wide basis, within say, the next 25 years. It is now 2015. This means we will prove a feasible solution to this problem by 2040. Needless to say, if we can initiate a pursuable solution to the global fresh water crisis by 2040, it will change geo-political conditions and the state of humanity forever.
In the current global industrial environment feasibility must be synonymous with affordability. I have never believed the only solutions to this problem will bankrupt civilization. Also, judge what you will, profit incentive, not just survival, must be a driver moving this project along in order to enlist the interest of private enterprise. As I see it, the creation of a dynamic, global new industry with unlimited potential in so many areas should fulfill this requirement.
In an admittedly simple but manageable fashion, I have broken down this global fresh water solution into 4 main categories (technology areas):
1. Process: Identify a process which is technically imaginable as well as feasible to pursue. We are seeking practical technology, not science fiction. Science fiction would be something like finding a water-covered planet in our solar system and transporting the water back to earth via a laser tunnel. A more practical solution might be using the sea water already covering two thirds of our planet, and in spite of the currently looming difficulties, creating from it an unlimited fresh water supply. Neither one of these is ultimately impossible, however, keep in mind our previously mentioned 25 year timetable. So, we must make the solution affordable, both financially and in terms of human resources.
2. Energy: How much energy and what forms of fuel will be needed to drive the conversion and distribution processes and how can it be attained? Again, this speaks to financial incentive and technical practicality.
3. Materials: The materials and natural resources consumed to implement a method such as this will define the costs, labor and commitment necessary. Whatever we use must upscale practically. We're not talking cups or gallons of water here, we're talking about re-hydrating continents. Also, we must use sustainable and environmentally friendly technologies that can withstand the test of time.
4. Distribution: This is the transportation of fresh water once it is available, to where it is needed. Here, the most familiar is not necessarily the winning idea. Distribution is closely linked to energy use and hence, affordability.
Discussion of the Process
In the scenario outlined in this paper, fresh water created from sea water is pumped into target, off-shore aquifers below the ocean floor. In many cases, these off-shore aquifers are known to be pre-connected via porous formations or fissures to adjacent fresh water aquifers which extend under continental shelves and further inland and serve as fresh water reservoirs for coastal populated areas. In cases where pre-existing connectivity does not exist, methods for creating geologic or artificial connections can be used, as discussed below (see Fig. 3).
This process utilizes a suite of existing technologies to create potable, fresh water from ocean water and inject this water directly into underground aquifers, under pressure, thus recharging a pre-existing but diminishing water supply. This is accomplished with the least expenditure of energy by having the process dwell offshore in coastal waters, on manmade platforms located directly above the target aquifers and sourcing our energy from the ocean itself.
Environmentally sustainable energy sources lend themselves perfectly to this scenario. The ocean is arguably the largest single source of renewable energy, offering a host of mechanical and thermal alternatives, examples including wind, solar, waves, tides, thermal and thermal differential technologies.
Essentially, what we are doing is reversing the process used to extract hydrocarbon fuels from the earth and instead using that technology to inject fresh water back into natural underground reservoirs.
Also note, this environmentally friendly repurposing of existing technologies, once it begins to scale, will create a new industry and many jobs.
a) Creating fresh water: First, we must obtain fresh water from sea water. In order to do this, we must choose the most efficient desalinization and conversion method(s) available to us today which is/are adaptable to our scenario.
The obvious contenders at this time would be distillation or reverse osmosis or perhaps a deionization process. The choice would be heavily dependent on cost which translates into energy, materials and manpower. Choices abound and a parallel deployment model where more than one process is used may be the best idea for efficiency and also to ensure system stability. Naturally, future methods might make the process even more efficient.
b) Fueling the enterprise: The energy used to fuel this process will be generated on location utilizing whichever renewable energy types we choose or a combination of multiple types. As mentioned above we have both oceanic mechanical and thermal energy sources to choose from as well as wind and sun. Almost no land-based or hydrocarbon fuels need be used to drive the main systems. In fact, as research and development favor newer sustainable energy technologies, the balance of power between components in a multiple energy source suite could dynamically change to favor efficiency here as well as with fresh water extraction.
c) Injection techniques: The method of injecting the resulting fresh water into subterranean aquifers and assuring dispersal of waters to adjacent geographical hydrous reservoir areas would be accomplished using various vertical and horizontal drilling techniques already in use and perhaps some techniques pioneered in the highly controversial field of hydraulic fracturing or 'fracking'.
Creating a new underground geo-network to enable a freshwater recharging system may be what strategic hydraulic fracturing was created for. In order to access existing aquifers, we can reengineer current fracking techniques to create injection systems rather than the current extraction systems used in shale deposit oil and natural gas retrieval.
Fracking creates cracks deep into rock formations and horizontal well stimulation techniques allow the opening of lateral channels, both which could be used to access aquifers and connect adjoining underground water reservoirs and porous, hydrous fields into larger systems which could be recharged from single or multiple points.
Nearly all the complaints environmentalists find in the hydrocarbon reclamation process through use of hydraulic fracturing do not apply here. In this use, there are very few toxic substances to leach into fresh water supplies (we are simply injecting new fresh water into existing fresh water sources) and the work will not disturb populated areas as it will, for the most part, be carried out offshore.
This process can be designed to be environmentally sensitive. Fracturing fluids can be brine-based (from seawater) and proppants (used in the fracking process to maintain integrity of bores) can be silica sand based (both already in use) to be as least disruptive to the environment as possible.
Research in this area should be done to identify biodegradable fracturing gels and proppants that will not contaminate ground water. Drilling away from known hydrocarbon deposits diminishes the risk of environmental cross-contamination. Understanding the ocean bio systems and anticipating ocean floor impact will minimize environmental shock. Combined with the proposed sustainable energy creation, this method is essentially a green technology.
Unintentional induced seismicity (creation of micro earthquakes) encountered in the boring process is one issue which will need to be addressed but any unexpected geological disturbances which might occur would also be isolated far from populated areas.
Currently we are seeing what looks like geological instability caused by retrieval fracking in the form of earth tremors or quakes. Part of the disruptive process has to do with the pressures needed to make extraction expeditious and therefore profitable. In this fresh water recharging plan, it should be possible to address this problem with reduced, acceptable charging pressures. The compensator is time. By slowing the process and reading geologic signals to calculate acceptable pressures, paths and procedures we can use the earth's communications in our favor. Sustainability can be achieved by pre-engineered responsive relentlessness.
Additionally, underground water deposits typically are found at considerably shallower depths than hydrocarbon deposits, therefore obviating the need to pass through oil or gas laden geographic formations to tap aquifers and greatly decreasing the probability of contaminant migration.
d) Distribution: Distribution of resulting new, fresh water - this is the most exciting aspect of this project as there is essentially little or nothing to be done. The extensive existing distribution system supporting populated areas now, remains intact and operational to continue to deliver water. We are simply extending the life of the source reservoirs by raising the water table and in no way require new distribution systems except as would normally be needed to service growing communities. We would continue to take advantage of the extensive, already existing, man-made water delivery system, wells, pumping stations, aqueducts, pipelines, etc., and not be required to build totally new transport or distribution networks.
Natural and manmade reservoirs, lakes, rivers and springs would continue to flow only with the addition of a higher water table, much as in the past, before population growth overstressed the natural groundwater reserves.
In certain cases where underground, geologic connectivity between aquifers will not be practical or possible, short, above-ground shunt lines (pipe, aqueduct or other transport) can convey new water from a refreshed subterranean reservoir to other bordering reservoirs (see Figure 3, below), perhaps even in a daisy-chain fashion. Again, no trans-continental transport is necessary.
Also, it should be noted, any existing natural filtering components of geological formations through which our new water passes will continue to act on the renewed water supply in the same manner as on the original water, thus bringing our freshly created supply in line with original supply potability indexes. This should minimize the need for additional, extensive filtering or purification as the water proceeds to the end-user.
Besides physical transport facility, we already have systems in place in many areas of the globe to manage and regulate water (dams, reservoirs and distribution centers as well as treaties, contracts, regulatory and oversight agencies). Both private and state-sponsored efforts should remain intact and continue to be relevant since the distribution system will not have been fundamentally altered. Current regulation, most of which was formulated when there was (arguably) more water available and less awareness of its fragility, would for the most part, continue to apply.
In order for a program such as what I have described here to come to fruition, private industry as well as governments must commit to its implementation. As with all potentially profitable enterprises, monitoring and regulation in the public interest needs to be in place. We have seen the difficulties encountered in the hydrocarbon extraction industry as the battle rages between private interests, environmental concerns and practical public energy needs. The resources wasted fueling this conflict are incalculable. At this rapidly decelerating stage of our global stewardship, we do not have the luxury of wasting resources on conflict. Inadequately regulated exploitation of this fresh water renewal system could put control of the globe's most valuable commodity in the hands of a few people or entities and set the scene for further conflict. Every effort must be made in the early stages to create, through regulation, an open-source system available to all.
The 25 year window of exploration I mention earlier in this document seems a ridiculously short amount of time to solve what is arguably the most pressing survival problem we face today. And yet, we have a 7 billion strong brain trust to work with and the most essential motivation, survival of humanity. This method of global rehydration or something developing from this idea can be imminently practical if we will take the problem seriously enough to make it a scientific and industrial priority.
As a civilization in crisis we need to focus our explorative endeavors more on practical initiatives and less on impractical pure, theoretical research. I know this rubs some people the wrong way but there is a time and place for everything and our emphasis at this time must be on addressing real problems and creating real-world solutions. Once we have created our utopia, we can indulge in the luxury of exploring distant planets and examining how the universe may have been created.
The loop between pure research and pragmatic results must be condensed at this crucial time. Our people need us now.
Figure 1: U.S. Aquifer Map
Figure 2: U.S. Aquifer Map with Rivers
Figure 3: U.S. Aquifer Map showing possible man-made shunts between aquifers