I have thought long and hard about how to fully recover energy from a vehicle braking, and the release it as torque to supplement the regular propulsion source, to get the vehicle rolling again. I have thought about pneumatics, hydraulics, mechanical and electromechanical means, but they all have downsides from poor life spans to high cost and weight. Then I remembered the steam cannon, which saw very limited use in the American Civil War, and again on the show MythBusters. The cannon used the power of water flashing to steam in a super heated barrel to fire the projectile, the theory was coal is cheaper then gunpowder. Well coal might have been cheaper, but on the battle field mobility is king. (This steam cannon would have been better suited for the stationary trench warfare of WWI, but it was ahead of it’s time, and that’s not the point.)
The same principle can be used to recover heat from braking and then basically make the car jump off the line. The system would work by continuing to use the electric motor to slow the car during hard braking. The massive current would then be feed to a coated resistant heater, to make it red hot. (To make it work better or on non-hybrid vehicles the exhaust gas could be routed through a restrictive ceramic baffle.) The captured heat would be stored in a super insulated vessel. Then when the gas pedal was depressed if the heat was sufficient, water would be injected, and allowed to flash to steam. The steam would then be released into a piston on a clutch and gearing system, connected to the drive shaft or transmission. The force of the steam would start the wheels turning, and get the car off the line. Then coolant would condense the steam, and reset the system. Remember steam engines have the most torque at low RPM, so the piston could basically throw the vehicle off the line.
If a special piston wasn’t acceptable, with changes to the valve timing the steam could be used to restart the vehicle’s combustion engine, and provide immense torque with no fuel use. This would also require very high quality rings and an oil dewatering system. However, this would require the car carry or be able to collect high purity water, since the water/steam would be lost out the exhaust valves.
Doing all this work just to make the car go a couple feet might seem excessive, but it takes a massive amount of fuel to make the car move. So if you can do it energy that otherwise would have been wasted, the savings could be huge possibly 10% or more in fuel economy. Plus, there is nothing like getting pushed back is the seat when you press the gas, and as I said steam would basically throw the car…
Sunday, October 21, 2007
Friday, October 19, 2007
Rescuing failed drugs with companion diagnostics
This post is related to what I do so I will very vague, and freely admit that I have a conflict of interest.
Depending on how the FDA deicide’s to deal with the new kinds of companion diagnostics this could be a golden age for drug companies. Why, because companion diagnostics could allow them to revive some of the drugs that failed in later phases.The biggest reason drugs fail in late stage as I understand it is a lack of efficacy. Well the drug got to the later phases because it worked in a subset of people, but failed because it didn't work in everyone. With some of the new technologies that have become available, the drug companies can go back to the samples they collected and figure out what was “different” about the people the drug worked on from those it didn't work on (using genomic, transcriptomic, proteomic, and/or any other method you can think of). For example if they find a genetic variation in people the drug didn't work on, then they design a low cost genetic test, that is run before the doctor decides what to write the Rx for.
There is a long history of companion diagnostics, it is just the current generation are well understood tests, for things like liver function. This brings up the second major reason drugs fail in late stage trials: very adverse reactions in a small percent of the population. In this case you do the same thing as before and figure out what was different between the two groups. Then have a test to make sure you never give the drug to people who it could be harmed by the drug. Imagine how well Merck could do if they could find a marker that predicted adverse reaction to Vioxx. They could put the drug or some kind of Cox2 inhibitor back on the market with a companion test. Then they could test all the people in class (action lawsuit) and potentially exclude some of the negative "events" as not drug related.
These sorts of tests are the beginning of personalized medicine. This has its ups and downs for everyone. For the drug companies they can rescue drugs that fail in later stage trials, but they won’t be able to make as much money on the drug once its releases since not everyone with a condition can take the drug. However, it still can work out for them, since if they have a drug that fails when they have $500 million invested in it, before they would have had to simply write down the lose. Now they can spend $10 million more figure out what’s going on and if need be create a companion diagnostic, and bring the drug to market. They might not make tons of money, but it seems making money slowly is preferable to losing money.
Now the customers will benefit since as the drug company’s revive their legacy of semi-failed drugs, personalized medicine gets a big boast. Now the down-side is that the drug companies won’t be able to sell as much of any one drug as they are use to, so the prices will be higher.
However, once companion diagnostics are considered as part of the drug development process the cost of drug development could go down, as it becomes easier to get a drug to market. The drug companies can use the information obtained from model systems and early clinical trails with prospective testing to segment the population. This can smooth out the road and make the longer more expensive later phase trials go more smoothly, since more of the variables are controlled.
In the near term I envision a new type of Pharma company, opportunists. These companies buy, for pennies on the dollar, the later stage failures from other companies, then try and figure out what happened and if they can get around the issue, and bring the drug to market. I could even see Teva getting into this market.
As I said, this could be the beginning of a golden age.
Depending on how the FDA deicide’s to deal with the new kinds of companion diagnostics this could be a golden age for drug companies. Why, because companion diagnostics could allow them to revive some of the drugs that failed in later phases.The biggest reason drugs fail in late stage as I understand it is a lack of efficacy. Well the drug got to the later phases because it worked in a subset of people, but failed because it didn't work in everyone. With some of the new technologies that have become available, the drug companies can go back to the samples they collected and figure out what was “different” about the people the drug worked on from those it didn't work on (using genomic, transcriptomic, proteomic, and/or any other method you can think of). For example if they find a genetic variation in people the drug didn't work on, then they design a low cost genetic test, that is run before the doctor decides what to write the Rx for.
There is a long history of companion diagnostics, it is just the current generation are well understood tests, for things like liver function. This brings up the second major reason drugs fail in late stage trials: very adverse reactions in a small percent of the population. In this case you do the same thing as before and figure out what was different between the two groups. Then have a test to make sure you never give the drug to people who it could be harmed by the drug. Imagine how well Merck could do if they could find a marker that predicted adverse reaction to Vioxx. They could put the drug or some kind of Cox2 inhibitor back on the market with a companion test. Then they could test all the people in class (action lawsuit) and potentially exclude some of the negative "events" as not drug related.
These sorts of tests are the beginning of personalized medicine. This has its ups and downs for everyone. For the drug companies they can rescue drugs that fail in later stage trials, but they won’t be able to make as much money on the drug once its releases since not everyone with a condition can take the drug. However, it still can work out for them, since if they have a drug that fails when they have $500 million invested in it, before they would have had to simply write down the lose. Now they can spend $10 million more figure out what’s going on and if need be create a companion diagnostic, and bring the drug to market. They might not make tons of money, but it seems making money slowly is preferable to losing money.
Now the customers will benefit since as the drug company’s revive their legacy of semi-failed drugs, personalized medicine gets a big boast. Now the down-side is that the drug companies won’t be able to sell as much of any one drug as they are use to, so the prices will be higher.
However, once companion diagnostics are considered as part of the drug development process the cost of drug development could go down, as it becomes easier to get a drug to market. The drug companies can use the information obtained from model systems and early clinical trails with prospective testing to segment the population. This can smooth out the road and make the longer more expensive later phase trials go more smoothly, since more of the variables are controlled.
In the near term I envision a new type of Pharma company, opportunists. These companies buy, for pennies on the dollar, the later stage failures from other companies, then try and figure out what happened and if they can get around the issue, and bring the drug to market. I could even see Teva getting into this market.
As I said, this could be the beginning of a golden age.
Thursday, October 18, 2007
New approaches to HIV treatments
Normally I don’t post things that could potentially be considered related to my job, but I figure a “fresh” look at potential HIV therapeutics is far enough away that I am not that concerned.
The first is a drug that increases the fidelity of the HIV reverse transcriptase. This sounds totally stupid, but one of the key mechanisms of viral survival is an error prone replication. One of the reasons that combination therapies fail is the virus mutates and the population becomes resistant. This drug would slow the mutation rate, and prolong the efficacy of these therapies. Obviously you can’t use this drug in combination with drugs that interfere with reverse transcription, (no AZT or what ever they are using now days) but it could stabilize the viral population, and slow the creation of multi-drug resistant strains.
The second treatment would be for individuals at risk or just recently exposed. Basically you would use lipid vesicles with gp120 as the targeting mechanism and RNA molecules that would target the HIV RNAs to Dicer as the payload. (The gp120 thing might not work so regular fusion vesicles could work as well, but you'd the lose the cellular targeting.) I’m guessing here but in cells that were not infected already it could serve as a molecular trap, so that when they became infected the HIV RNA would be destroyed, and be unable to integrate. In cells that were already infected it could suppress the translation of viral proteins and possibly the creation of viral genomes.
The next two suggestions are that people focus on the viral proteins Rev and Nef as drug/treatment targets, since both of these proteins are required for successful HIV infections and since they interact with the host they can mutate very much and still be functional. The treatment could be either small molecule or suppressive RNA. I would suggest suppressive RNA since small molecules that could suppress these proteins might also have activities against host proteins as well.
It could be useful to interfere with Vif, but it might be more useful to instead up-regulate Vif’s target APOBEC3G. Interestingly if a drug that could suppress Cullin5 E3 ubiquitin ligase (Vif hijacks this protein to degrade the APOBEC3G) was available it would not only serve as a very effective HIV therapeutic but it could also treat autoimmune diseases as well.
The best way I see to deal with Tat is using engineered antibodies, that bind important (conserved) but not normally highly immunogenic epitopes. This kind of treatment could damage the spleen and kidneys of AIDS patients so they will likely need some kind of secondary therapy “blood cleansing” to remove the Tat/Ab complex from the blood. I would suggest a secondary antibody that recognizes an epitope in the primary antibody that is created by binding Tat. The antibody can be bound to a substrate, and the patient’s blood passed over it. If their blood has to be outside their body anyways; why not deplete it for gp120? This would just inactivate any virus particles in the blood and reduce the chance that infected cells will produce functional virus for a couple days.
Unfortunately even if it was possible to totally suppress an HIV infection, we would just have a new problem, blood cancers. HIV integrates into the host genome, which is why it is so hard to get rid of. Now days, the infected cells and sometimes the host die before this becomes too much of a problem. Once people start living a long time with a chronic HIV infection, some of the cells will have an HIV integration event that alters the expression of an important gene. This event can be the start of some fairly nasty T-cell leukemia’s. However, I suggest we worry about this problem once HIV is no longer the killer it is.
The first is a drug that increases the fidelity of the HIV reverse transcriptase. This sounds totally stupid, but one of the key mechanisms of viral survival is an error prone replication. One of the reasons that combination therapies fail is the virus mutates and the population becomes resistant. This drug would slow the mutation rate, and prolong the efficacy of these therapies. Obviously you can’t use this drug in combination with drugs that interfere with reverse transcription, (no AZT or what ever they are using now days) but it could stabilize the viral population, and slow the creation of multi-drug resistant strains.
The second treatment would be for individuals at risk or just recently exposed. Basically you would use lipid vesicles with gp120 as the targeting mechanism and RNA molecules that would target the HIV RNAs to Dicer as the payload. (The gp120 thing might not work so regular fusion vesicles could work as well, but you'd the lose the cellular targeting.) I’m guessing here but in cells that were not infected already it could serve as a molecular trap, so that when they became infected the HIV RNA would be destroyed, and be unable to integrate. In cells that were already infected it could suppress the translation of viral proteins and possibly the creation of viral genomes.
The next two suggestions are that people focus on the viral proteins Rev and Nef as drug/treatment targets, since both of these proteins are required for successful HIV infections and since they interact with the host they can mutate very much and still be functional. The treatment could be either small molecule or suppressive RNA. I would suggest suppressive RNA since small molecules that could suppress these proteins might also have activities against host proteins as well.
It could be useful to interfere with Vif, but it might be more useful to instead up-regulate Vif’s target APOBEC3G. Interestingly if a drug that could suppress Cullin5 E3 ubiquitin ligase (Vif hijacks this protein to degrade the APOBEC3G) was available it would not only serve as a very effective HIV therapeutic but it could also treat autoimmune diseases as well.
The best way I see to deal with Tat is using engineered antibodies, that bind important (conserved) but not normally highly immunogenic epitopes. This kind of treatment could damage the spleen and kidneys of AIDS patients so they will likely need some kind of secondary therapy “blood cleansing” to remove the Tat/Ab complex from the blood. I would suggest a secondary antibody that recognizes an epitope in the primary antibody that is created by binding Tat. The antibody can be bound to a substrate, and the patient’s blood passed over it. If their blood has to be outside their body anyways; why not deplete it for gp120? This would just inactivate any virus particles in the blood and reduce the chance that infected cells will produce functional virus for a couple days.
Unfortunately even if it was possible to totally suppress an HIV infection, we would just have a new problem, blood cancers. HIV integrates into the host genome, which is why it is so hard to get rid of. Now days, the infected cells and sometimes the host die before this becomes too much of a problem. Once people start living a long time with a chronic HIV infection, some of the cells will have an HIV integration event that alters the expression of an important gene. This event can be the start of some fairly nasty T-cell leukemia’s. However, I suggest we worry about this problem once HIV is no longer the killer it is.
The future of paper
No matter what you’ve read or heard, paper isn't going away anytime soon. I know people who print their email. (Honestly sometimes, I kind of think it's a good idea.) However, paper comes from trees, and honestly that isn't the best idea, since trees grow slowly which makes sustainability difficult.
What we need is a way to make semi-natural cellulose fibers out of a sustainable, renewable material. Optimally it needs to be a perennial legume. The problem is plants like that produce short often branched chain cellulose instead of the more desirable long chain (woody) structural cellulose.
Right now there is a lot of research going into enzymes that can cleave cellulose into sugar so yeast can be used to ferment biomass into ethanol for fuel. We need research in the other direction, where short cellulose molecules are linked to make long molecules. The branching chains could then be cleaved and the long molecules cross linked, to make them more rigid. The resulting fibers could be used as pulp for paper making. Since the fibers are not from trees they will be naturally whiter and free of lignin, so they will require fewer chemical treatments.
Possibly the fibers could spun like cotton to make renewable cloth. Cotton may be a great cash crop but due to its high fertilizer, water and pest spraying needs it isn't that great for the environment. Even if the fibers are too coarse for spinning they could be used in engineered wood products to reduce the need for farmed trees. Engineered wood products are actually a better possible use of semi-natural cellulose. By replacing whole wood products with a sustainable material it could really help make forestry a more sustainable industry.
Ok you might be thinking great where do we get the land to grow billions of tons of clover? We don't have to; this process should work with leaves, farm waste, and grass clippings. Plus by seeding the reactor with already longish fibers from low grade recycled paper, the useful life of the fibers is extended, and the reaction efficiencies can be increased. Even if it isn't possible to make paper grade cellulose out of soft stemmed plants, these enzymes could used to "upgrade" lower quality short cellulose.
Another possibility is to move away from plant based cellulose and use cellulose produced by microorganisms, via aerobic fermentation. I am not sure how you would market paper made from sewer water, but I am sure someone could do it.
Imagine large ponds filled with sewer water, and bubbled with flue gas, covered with a cm thick layer of cellulose bound microorganisms (biofilm). Every once in a while you skim it off, render the lipids for biodiesel, the protein for animal feed, the soluble carbohydrates for ethanol production, and the rest becomes paper, or the boards in someone’s back deck. Oh and the water comes out cleaner and ready to go into a swamp or river for final purification.
What we need is a way to make semi-natural cellulose fibers out of a sustainable, renewable material. Optimally it needs to be a perennial legume. The problem is plants like that produce short often branched chain cellulose instead of the more desirable long chain (woody) structural cellulose.
Right now there is a lot of research going into enzymes that can cleave cellulose into sugar so yeast can be used to ferment biomass into ethanol for fuel. We need research in the other direction, where short cellulose molecules are linked to make long molecules. The branching chains could then be cleaved and the long molecules cross linked, to make them more rigid. The resulting fibers could be used as pulp for paper making. Since the fibers are not from trees they will be naturally whiter and free of lignin, so they will require fewer chemical treatments.
Possibly the fibers could spun like cotton to make renewable cloth. Cotton may be a great cash crop but due to its high fertilizer, water and pest spraying needs it isn't that great for the environment. Even if the fibers are too coarse for spinning they could be used in engineered wood products to reduce the need for farmed trees. Engineered wood products are actually a better possible use of semi-natural cellulose. By replacing whole wood products with a sustainable material it could really help make forestry a more sustainable industry.
Ok you might be thinking great where do we get the land to grow billions of tons of clover? We don't have to; this process should work with leaves, farm waste, and grass clippings. Plus by seeding the reactor with already longish fibers from low grade recycled paper, the useful life of the fibers is extended, and the reaction efficiencies can be increased. Even if it isn't possible to make paper grade cellulose out of soft stemmed plants, these enzymes could used to "upgrade" lower quality short cellulose.
Another possibility is to move away from plant based cellulose and use cellulose produced by microorganisms, via aerobic fermentation. I am not sure how you would market paper made from sewer water, but I am sure someone could do it.
Imagine large ponds filled with sewer water, and bubbled with flue gas, covered with a cm thick layer of cellulose bound microorganisms (biofilm). Every once in a while you skim it off, render the lipids for biodiesel, the protein for animal feed, the soluble carbohydrates for ethanol production, and the rest becomes paper, or the boards in someone’s back deck. Oh and the water comes out cleaner and ready to go into a swamp or river for final purification.
Wednesday, October 17, 2007
Gore's partial Nobel
There is a great deal irony in Gore getting a Nobel Prize. Even better it is a different irony than the Nobel Peace Prize alone.
For those who don't know the Nobel Prize was funded at least originally by the money Alfred Nobel made from his invention of safe Dynamite. I admire Nobel, so don't misunderstand. But safe explosives helped bring about the age of modern warfare, and made large scale civil projects, and resource utilization possible. This is why I find the selection process ironic, that they gave an award for championing the environment. However, that irony is not my point.
The irony I enjoy most is that Gore and the others will get a large medal made of gold. To produce that medal created literally tons of CO2 plus put sulfur and nitrogen oxides into the air while putting various heavy metals and HCN into the water. I didn't see the medal, but unless Gore's medal is made of recycled newspaper, there is irony.
I also doubt that he'll take a bicycle or even a hybrid car to get the medal, that private jet Gore tools around in produces tons more CO2 and worse water vapor at high altitudes. (To be honest I am writing this at ~33K feet, so I am not exactly part of the solution, but they are over a hundred other people sharing my plane.)
However, I will give him a credit for wearing recycled fibers in his clothes. Sure silk is recycled caterpillar cocoons. Ok, so it's not recycled...
Now if Gore accepts the medal by WebEx or on Second Life, and they make the medal out of locally sourced recycled glass with a corn plastic binder, then most of the irony is gone. But until then...
Now from fact to opinion:
I doubt Gore will make a serious run for President, but he'll stir the pot, so he remains relevant, but to actually run would require returning to a past I imagine he’d rather forget.
Plus, it’s only fun to throw stones, it isn’t fun to have them thrown at you.
I would like to see Gore run for President of Second Life, since that is the greenest technology I can think of. (The Matrix metaphor is not lost on me.)
For those who don't know the Nobel Prize was funded at least originally by the money Alfred Nobel made from his invention of safe Dynamite. I admire Nobel, so don't misunderstand. But safe explosives helped bring about the age of modern warfare, and made large scale civil projects, and resource utilization possible. This is why I find the selection process ironic, that they gave an award for championing the environment. However, that irony is not my point.
The irony I enjoy most is that Gore and the others will get a large medal made of gold. To produce that medal created literally tons of CO2 plus put sulfur and nitrogen oxides into the air while putting various heavy metals and HCN into the water. I didn't see the medal, but unless Gore's medal is made of recycled newspaper, there is irony.
I also doubt that he'll take a bicycle or even a hybrid car to get the medal, that private jet Gore tools around in produces tons more CO2 and worse water vapor at high altitudes. (To be honest I am writing this at ~33K feet, so I am not exactly part of the solution, but they are over a hundred other people sharing my plane.)
However, I will give him a credit for wearing recycled fibers in his clothes. Sure silk is recycled caterpillar cocoons. Ok, so it's not recycled...
Now if Gore accepts the medal by WebEx or on Second Life, and they make the medal out of locally sourced recycled glass with a corn plastic binder, then most of the irony is gone. But until then...
Now from fact to opinion:
I doubt Gore will make a serious run for President, but he'll stir the pot, so he remains relevant, but to actually run would require returning to a past I imagine he’d rather forget.
Plus, it’s only fun to throw stones, it isn’t fun to have them thrown at you.
I would like to see Gore run for President of Second Life, since that is the greenest technology I can think of. (The Matrix metaphor is not lost on me.)
Thursday, October 11, 2007
An even more inconvenient truth
Here’s a fact that the global warming fear mongers tend to leave out, water vapor is a greenhouse gas, and in fact it is an excellent greenhouse gas. If you don’t believe me go to Houston in the summer. Ok that isn’t the "actual" greenhouse effect it just feels like one.
To be a greenhouse gas a molecule must be able to absorb and emit IR, which means it must have a dipole moment, and that is water in spades (H-O-H with the hydrogen’s having a partial + while the oxygen has a partially -) . Even if H2O wasn’t a better greenhouse gas than CO2, it is present in atmosphere at concentrations hundreds of times higher than CO2.
Current estimates pin 36-70% of the greenhouse effect on water vapor. Why is that fact left out of most scarce campaigns? Because, no matter how green the technology if there is combustion water vapor is a product, and global warming gets worse. Also, how popular do you think it would be they were telling people that watering their lawn or planting a non-native tree, was destroying the environment? It is easier to tell people that by recycling bottles and cans and driving a hybrid vehicle they can make a difference.
Some day soon we might be talking about “fossil water” or something equally catchy. Since the more water we pump out of the ground or melt out of ice packs or create by burning fossil fuels, the worse the problem becomes because that water was locked up before and not a big part of the atmospheric model. As we alter the vapor partial pressure of the planet by adding more water then sublimation and evaporation could alone, this could alter the weather and accentuate the “greenhouse” effect.
So, if we really want to make a difference we will ditch the hydrogen economy (hydrogen gas destroys the ozone layer, so that is another strike against it) and go nuclear with solar, and wind generation for peaking. (Hydro and tidal power heat the water, which releases water vapor, but over all it is very benign, so I guess they are ok too.)
Yes, nuclear has a bad reputation, but it is combustion free, and assuming we switch to sub-critical reactors, reprocessing, and managed disposal (instead of bury it and forget it), it can be safer.
The thing we should worry about most and work the hardest to conserve is water, since water is precious to life and wasting it actually hurts twice.
Don’t be fooled by the questionable science! Being “carbon neutral” at the expensive of a heavy water footprint could make things worse. Don’t make CO2 the scapegoat for all the worlds’ woes. As a nation and a planet we need to figure out how to solve the real problems.
To be a greenhouse gas a molecule must be able to absorb and emit IR, which means it must have a dipole moment, and that is water in spades (H-O-H with the hydrogen’s having a partial + while the oxygen has a partially -) . Even if H2O wasn’t a better greenhouse gas than CO2, it is present in atmosphere at concentrations hundreds of times higher than CO2.
Current estimates pin 36-70% of the greenhouse effect on water vapor. Why is that fact left out of most scarce campaigns? Because, no matter how green the technology if there is combustion water vapor is a product, and global warming gets worse. Also, how popular do you think it would be they were telling people that watering their lawn or planting a non-native tree, was destroying the environment? It is easier to tell people that by recycling bottles and cans and driving a hybrid vehicle they can make a difference.
Some day soon we might be talking about “fossil water” or something equally catchy. Since the more water we pump out of the ground or melt out of ice packs or create by burning fossil fuels, the worse the problem becomes because that water was locked up before and not a big part of the atmospheric model. As we alter the vapor partial pressure of the planet by adding more water then sublimation and evaporation could alone, this could alter the weather and accentuate the “greenhouse” effect.
So, if we really want to make a difference we will ditch the hydrogen economy (hydrogen gas destroys the ozone layer, so that is another strike against it) and go nuclear with solar, and wind generation for peaking. (Hydro and tidal power heat the water, which releases water vapor, but over all it is very benign, so I guess they are ok too.)
Yes, nuclear has a bad reputation, but it is combustion free, and assuming we switch to sub-critical reactors, reprocessing, and managed disposal (instead of bury it and forget it), it can be safer.
The thing we should worry about most and work the hardest to conserve is water, since water is precious to life and wasting it actually hurts twice.
Don’t be fooled by the questionable science! Being “carbon neutral” at the expensive of a heavy water footprint could make things worse. Don’t make CO2 the scapegoat for all the worlds’ woes. As a nation and a planet we need to figure out how to solve the real problems.
Protecting wells from brine infiltration
Many coastal cities are facing water shortages not because there is not water down their wells, but because brine infiltration has made the water undrinkable. Brine infiltration occurs when fresh and salty ground water interface. Normally the balance of pressure keeps the salty water away from shore and underneath the fresh water. However, when you disturb this balance by pumping the fresh water, first the salt water will mix with the fresh water making the water briny. This is the warning, if you keep pumping eventually the salty water will actually be able to push its way inland, and the well will produce salt water. Once salt water intrudes on the fresh even if the pumping stops, this can take years for the salty water to be flushed out and the well become drinkable again.
Now what do you do if cannot stop withdrawing groundwater? Well if you have an excellent hydrological model, you could strategically place wells out at sea and begin withdrawing the salty water to rebalance the pressure and give the fresh water a chance to push back out to sea. It wouldn’t be that hard, your city would model the fresh withdraw cone, and rent near shore oil drilling equipment, and drill several wells (preferably with horizontal drilling equipment so all the wells can share a single platform.) Once you have the wells you start pumping, if you want to be green about it you use methane from the landfill or wind power to run the pumps. You create several withdraw cones in the salt water that completely shields your fresh water wells, and wait for things to stabilize.
In case someone who could actually do what I am suggesting reads this (an extremely unlikely event), there are a lot of things you need to think about before attempting to shield your freshwater wells from brine inflitration. The big one is subsidence of the seafloor caused by the massive amount of water you would need to withdraw to make this work. It doesn’t sound like it should be a big deal if the seafloor sinks, but it could be. It could cause a change in way the currents flow, which might cause silting or alter navigation features. If there are methane hydrates in the seafloor it could destabilize them, which would be a HUGE problem. Think massive cloud of deadly and flammable gas and huge tsunami. Even if you don’t have methane hydrates if you are causing subsidence on a slope, you might trigger an underwater landslide, and accompanying the tsunami… Assuming you can prove to the insurance people this won’t happen, you will still have to prove to the EPA that the water you will be pumping up and dumping in the sea which will have a different temperature and level of salinity won’t be harmful.
If you manage to do all this, and can afford the energy, feel free to use this idea to save your cities fresh water supply. Perhaps it would be a better idea to leave the water in the ground and just build desalination plants.
Now what do you do if cannot stop withdrawing groundwater? Well if you have an excellent hydrological model, you could strategically place wells out at sea and begin withdrawing the salty water to rebalance the pressure and give the fresh water a chance to push back out to sea. It wouldn’t be that hard, your city would model the fresh withdraw cone, and rent near shore oil drilling equipment, and drill several wells (preferably with horizontal drilling equipment so all the wells can share a single platform.) Once you have the wells you start pumping, if you want to be green about it you use methane from the landfill or wind power to run the pumps. You create several withdraw cones in the salt water that completely shields your fresh water wells, and wait for things to stabilize.
In case someone who could actually do what I am suggesting reads this (an extremely unlikely event), there are a lot of things you need to think about before attempting to shield your freshwater wells from brine inflitration. The big one is subsidence of the seafloor caused by the massive amount of water you would need to withdraw to make this work. It doesn’t sound like it should be a big deal if the seafloor sinks, but it could be. It could cause a change in way the currents flow, which might cause silting or alter navigation features. If there are methane hydrates in the seafloor it could destabilize them, which would be a HUGE problem. Think massive cloud of deadly and flammable gas and huge tsunami. Even if you don’t have methane hydrates if you are causing subsidence on a slope, you might trigger an underwater landslide, and accompanying the tsunami… Assuming you can prove to the insurance people this won’t happen, you will still have to prove to the EPA that the water you will be pumping up and dumping in the sea which will have a different temperature and level of salinity won’t be harmful.
If you manage to do all this, and can afford the energy, feel free to use this idea to save your cities fresh water supply. Perhaps it would be a better idea to leave the water in the ground and just build desalination plants.
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