Potential impacts of CCS to underground sources of drinking water

Water is our most precious resource - one we often take for granted.  Much of the United States is predicted to have a water shortage.... we need to take great measures to protect it.

CO2 sequestration is also known as "CCS"  or "GCS" - for geological carbon sequestration.

Risks to our drinking water -

The following quotes come the article linked at the end of this posting.

"There are several potential scenarios by which a USDW may be impacted by GCS activities. Potential pathways include upward migration, fractured cap rock, faults, trace contaminants included in the CO2 stream, a microannulus outside the final casing, and the mobilization of metals from native minerals."


"The success of GCS relies on the structural integrity of confining units, for trapping CO2 in underlying permeable formations. Injection of CO2 into the receiving aquifer has the potential to cause deformation, trigger seismicity, reactivate faults, and compromise seals in wells. Each of these processes could increase the risk of leakage jeopardizing containment and the protection of groundwater quality." 

"Risk is typically defined as the product of the probability of occurrence of an event and the negative consequence of the event. There are concerns that there is limited likelihood data concerning the consequences of GCS, which might result in either over or underestimation of chances of occurrence. Water purveyors take pride in meeting their mandate to protect the public health by providing safe clean drinking water.

While the probability of a USDW being significantly impacted may be low, the negative consequences of any such incident have the potential to be very high. The proposed rule requires operators of GCS facilities to provide financial assurances adequate for corrective actions, plugging and abandonment of wells, post injection site care and closure, and emergency response for failed injection wells. The question of how to structure liability for long-term risks to USDWs associated with the geologic sequestration of CO2 has not yet been resolved."

Read the full article here

Read the full article here

Research for Deployment: Incorporating Risk, Regulation,and Liability for Carbon Capture and Sequestration

Carbon capture and sequestration (CCS) has the potential to enable deep reductions in global carbon dioxide (CO₂) emissions, however this promise can only be fulfilled with large-scale deployment. For this to happen, CCS must be successfully embedded into a larger legal and regulatory context, and any potential risks must be effectively managed. We developed a list of outstanding research and technical questions driven by the demands of the regulatory and legal systems for the geologic sequestration (GS) component of CCS. We then looked at case studies that bound uncertainty within two of the research themes that emerge. These case studies, on surface leakage from abandoned wells and groundwater quality impacts from metals mobilization, illustrate how research can inform decision makers on issues of policy, regulatory need, and legal considerations. A central challenge is to ensure that the research program supports development of general regulatory and legal frameworks, and also the development of geological, geophysical, geochemical, and modeling methods necessary for effective GS site monitoring and verification (M&V) protocols, as well as mitigation and remediation plans. If large-scale deployment of GS is to occur in a manner that adequately protects human and ecological health and does not discourage private investment, strengthening the scientific underpinnings of regulatory and legal decision-making is crucial.

Potential Groundwater Quality Impacts from Metals Mobilization.

Groundwater merits special attention because it is a precious resource, and it is subject to current regulation. While there are several ways in which large-scale injection or leakage might affect water supplies, most attention has focused on CO₂−brine−rock interactions. While processes in this system could affect both organic and inorganic geochemistry of aquifers, only the mobilization of inorganic compounds, chiefly metals, through dissolution and transport will be considered here.

South Liberty (Frio) Pilot, TX.

In 2004, a DOE pilot field experiment in South Liberty, TX injected 1800 t of CO₂ into the Frio saline formation (29). This injection was designed to validate simulations of CO₂ transport and fate in one of the largest saline formations in the United States. A monitoring well located 100 ft. from the injection well collected direct fluid samples using a U-tube apparatus (30). This tool and others detected arrival of a CO₂ plume in the monitoring well 7 days after injection.

Of note, a substantial amount of dissolved metal was recovered in the U-tube (31). Initially, workers thought that the well casing was reacting to carbonic acid in the reservoir. However, laboratory studies and geochemical analyses confirmed that a substantial fraction of the metals were the product of mineral dissolution, specifically the oxide and hydroxide coatings of mineral grains that represent <2%>31). The rapidity of mobilization and the high concentrations suggested strongly that carbonic acid formed from dissolved CO₂ in formation brines might quickly and dramatically alter groundwater chemistry.

The Frio was the first saline formation analyzed in this way. Ultimately, this result is not unexpected, yet it is not clear whether this effect of metal mobilization is common or significant at depth. It is also not clear what fraction of metals would be transported with CO₂ should it leak to other formations. However, it raised the concern that should CO₂ leak into a shallow freshwater aquifer, there could be consequences that could negatively affect groundwater quality, potentially impacting public health and acceptance of CCS deployment.

Carbonate and Siliclastic Systems.

To a first order, both injection targets and shallow aquifers can be divided into siliciclastic or carbonate systems. This division reflects the primary composition of the reservoir rocks. Carbonate systems chiefly comprise calcite, aragonite, dolomite, and other carbonate minerals that form limestones and dolostones, whereas siliciclastic systems chiefly comprise frag ments of quartz, feldspar, and other siliceous minerals that form sandstones, siltstones, and shales.

This compositional difference greatly affects the response of carbon acid. Silicate minerals react slowly with CO₂, which means that there is little change in porosity and permeability over the duration of injection; however, the brines with dissolved CO₂ will remain acidic. In contrast, carbonate rocks react quickly with CO₂ and could change permeability and porosity quickly; however, the rapid kinetics will result in rapid increase of brine pH and buffering of the brine−CO₂ system, reducing reactivity over time. Because of these competing effects, it is not clear which fundamental rock composition is more prone to leakage or to mobilizations of metals, and little work has focused on direct comparison of these two primary aquifer compositions.

Key U.S. Freshwater Aquifer Settings.

Given the distribution of CO₂ point sources and potential GS reservoirs, it is likely that CO₂ storage will be concentrated in a small number of basins. To understand and appraise the potential for metal mobilization in shallow aquifers, it would be helpful to understand the composition and acid-reaction response near the surface of these basins. Table 2 provides a subset of key shallow aquifers in these basins and some issues around their geology.

Risks Related to CO2 Sequestration, - LOTS OF RISKS

This is a great link to a web page that has A LOT OF INFORMATION about the risks associated with CO2 sequestration, also referred to as Geosequestration or "GS" - scroll up and down... you will find it addresses things like - risks to workers, the public, ecosystem, microbes in the ground, drinking water and the contamination it is likely to cause, it is one of the most complete sources of risks that I have seen for CCS ( Carbon Capture and Sequestration)

Click below -
This link is WELL WORTH YOUR TIME!


ADDITIONAL INFORMATION Below -from the web site:
http://solveclimate.com/blog/20090320/ccs-cant-make-tar-sands-clean
Click on the link to read the entire article... bold print is my emphasis.

"Chasing CCS is a money burner and an energy hog, and it may not deliver much carbon savings. The whole reactive proposition raises extreme security and liability issues for industry and taxpayers alike.

It Takes Energy to Bury CO2

The chief obstacle to CCS is cost. Right now, no country buries lots of CO2 because it is not economical. John Pavlish, a senior U.S. researcher on CCS at North Dakota's Energy and Environmental Research Center, notes that CCS would raise the cost of a power plant by 35 to 100 percent which, in turn, would increase electric bills by 30 to 80 percent. Without a $40 to $80 price tag on a tonne of CO2, not much carbon will ever get buried.

It takes a lot energy to capture, compress and inject CO2 into the ground. In fact 30, percent of the power generated by a coal-fired facility or tar sands power plant would be cannibalized by a CO2 retrofit.

That’s great news for coal companies because CCS demands that utilities burn more coal instead of building windmills.

Storage problems

Security of storage is also a concern. Not too many places in North America are suitable for carbon burial due to earthquake risks or high density oil and gas drilling. Improperly sealed wells or faulty cement jobs could invite great volumes of CO2 back to the surface. Leaks could also acidify groundwater.

The Intergovernmental Panel on Climate Change, for example, dutifully notes that Alberta is a pin cushion. With more than 350,000 oil and gas wells, it is one of the most intensely drilled landscapes in the world. In other words, CO2 could find its way back to the surface and into people’s basements and wells.

CO2 injection may also cause man-made earthquakes. The rapid depletion of gas wells and the water flooding of oil wells have caused a series of documented earthquakes in Alberta, Texas and the Netherlands. Geologists call it “induced seismicity.” The largest earthquakes ever recorded in Alberta were triggered by oil and gas activity. Natural Resources Canada recently studied a series of earthquakes caused by sour gas removal at the Strachan gas plant in Rocky Mountain House.

Although the technology for capturing, compressing and piping carbon is doable, not much is known about rapid CO2 injection into old oil reservoirs or salty aquifers.

Independent research by University of Calgary engineer Minzghe Dong shows that each and every reservoir behaves differently and has to be carefully prepared. If most of the oil and water isn’t removed, the reservoir will chemically react with CO2 and limit the amount of disposal space. Scientists have yet to show that the rock cap sealing salt aquifers can actually safely contain CO2.

Liability is no small cross in the carbon cemetery either. Buried CO2 must be monitored for thousands of years, a task few regulators really want to undertake. Industry doesn’t want to invest in CCS until government (read taxpayers) assumes the liabilities of leaks and groundwater contamination. Wyoming, the largest coal producing state, wisely passed legislation that places the liability for the unintended consequences of CCS on the utility or oil company that injects it.

It is reactive program, not a proactive one. The technology costs too much and won't scale up in time to make a difference. It directly robs taxpayers and subsidizes the world’s wealthiest industry. And it steals dollars from renewable programs. What CCS does is give coal and oil companies taxpayer money to accelerate hydrocarbon consumption by nearly one third."

WARNING - CO2 Sequestration Danger - What goes into the ground is NOT bubbles or carbonation!

It is supercritical CO2 and carries a lot of risks -

The full article is here - some excerpts from the article are below

Health hazards from CO2

"At room temperature and ambient pressure, CO2 is a colourless, odourless gas that supports neither combustion nor life. It is not just an asphyxiant but also has toxicological effects and has been recognised as an occupational health hazard for more than a hundred years.

Dense phase and supercritical CO2 give rise to additional hazards particularly when the pressure suddenly falls or is lost completely."

Further information on the cryogenic, traumatic and toxicological effects



General hazards of carbon dioxide

At room temperature and ambient pressure CO2 is a colourless, odourless gas that will not support combustion or human life. CO2 has been recognised as a workplace hazard for over a century. It is significantly heavier than air and many fatalities from asphyxiation have resulted from entry into pits, tanks, sumps or cellars where CO2 has accumulated and displaced oxygen.

It is also possible for dangerous levels of CO2 to form out-of-doors in trenches, depressions or valleys. This is particularly likely when the gas is colder than the surrounding air, which may occur following pressurised release.

In 2000, a US Environmental Projection Agency study on CO2 related incidents in fire scenarios reported that since 1975 there were 51 recorded incidents involving the discharge of CO2 fire extinguishing systems resulting in 72 deaths and 145 injuries.

There is no significant inherent human response to CO2 that could be useful as a detection mechanism. Human response to hydrogen sulphide by smell occurs at very low (ppm) concentrations, similarly with ammonia and sulphur dioxide.

In contrast, CO2 is present in the air we breath (0.037%). This may cause problems with instrumented detection because the 'background' CO2 levels are so high. In addition, the cooling effects of a pressurised CO2 leak may have an adverse effect on the accuracy and operability of CO2 gas detection systems.

The recognition of the dangers of CO2 has prompted much research into its toxicity in both human volunteers and animals. It is now known that, in addition to the problem of asphyxiation due to the displacement of oxygen, the inhalation of elevated concentrations of CO2 can increase the acidity of the blood triggering adverse effects on the respiratory, cardiovascular and central nervous systems. Data from published research reports has been used by HSE to quantify the toxicity of CO2 in the form of Dangerous Toxic Load (DTL)1 values.

The DTLs have been used in calculations by the Health and Safety Laboratories (HSL) to demonstrate that CO2 exhibits major accident potential, when transported by pipeline in large quantities at ambient temperature and at a pressure of 7 bar or more, well below the dense phase or supercritical region. It is not yet clear whether controls should be applied to the transport of CO2 in this context but pending further research, it is possible that HSE will propose amending the Pipelines Safety Regulations to include CO2 as a dangerous fluid.

Additional hazards of dense phase or supercritical carbon dioxide

For economic and technical reasons it is likely CO2 will be handled close to or above its critical pressure (73.82 bar) where many of its properties are similar to that of a liquid. In this state it is often referred to as a dense phase fluid, whereas above critical temperature (31.04oC) and pressure it is referred to as supercritical. Most of the additional hazards associated with dense phase or supercritical CO2 arise when this pressure suddenly falls or is lost completely.

Scale of the thermal cooling envelope

In the event of a major pressure loss, e.g a pipe rupture or containment failure, the depressurisation will result in an increase in the volume occupied by the CO2 of several hundred fold as the escaping fluid undergoes a rapid expansion (and phase change) as a proportion essentially 'boils' and becomes a gas while the remainder forms solid particles. This rapid, violent expansion causes the temperature of escaping CO2 to fall very rapidly, frequently below -80°C. while the particles of solid CO2 formed (dry ice) will result in projectiles expelled at very high velocities.

Cryogenic burns and impact injuries from extremely cold jet of gas and entrained missiles are serious hazards to personnel. Cryogenic embrittlement of structural steelwork and adverse effects from the impingement of extremely cold gas jets on safety-critical equipment are major threats to the structural and functional integrity of nearby plant unless appropriately designed or protected.


Toxic contamination effects

Supercritical CO2 is a highly efficient solvent. When supercritical CO2 undergoes a significant pressure reduction it moves from its supercritical state with super solvent properties to a gaseous state with virtually no solvent capability. In any environment where other substances are present with supercritical CO2 their solvation will occur resulting in fluid medium or "solution" containing various compounds or elements many of which may be extremely toxic. Any toxic substance held in such a pressurised 'solution' will 'precipitate' out on loss of pressure or containment and is likely to result in harmful human exposure or environmental damage due to the contamination of the area of deposition unless appropriate measures are taken.


Dry Ice 'grit blasting effects'

Where captured CO2 may be present with solid particles such as reservoir-derived sand and other solid debris, loss of containment may result in these combining with the dry ice formed to produce particles of a much greater abrasive capability than dry ice alone. This would enhance the erosion effects on process pipework and vessels adjacent to the leak which could lead to further damage to equipment and hence risk to people.


Specific challenges associated with dense phase or supercritical carbon dioxide

Whilst the processes that make up Carbon Capture and Storage (CCS) are not novel in themselves there is relatively little experience worldwide in managing the risks associated with CO2, compared with oil and gas. The major accident hazards presented by handling high pressure CO2 offshore or onshore need to be considered in the context of about 10,000 years' operating experience in managing hazards associated with hydrocarbon processing offshore alone, and probably much more if onshore processes are included2. In comparison there are probably less than 100 operating years for handling CO2 and significantly less in dealing with supercritical CO2. For Example, the Sliepner CO2 disposal project has been operational since about 1996 while in the USA, CO2 injection into wells has only been carried out over the last ~40 years.


Modelling dense phase/supercritical CO2 releases

The ability to anticipate foreseeable major accident scenarios and accurately predict the consequences of these hazardous events is a fundamental element in the assessment of the risk. A lack of substantial operation experience in a novel process or technology generally leads to significant difficulties in identifying accurately the hazards associated with that process or technology.

We do not yet fully understand the behaviour of CO2 when released from dense phase. Industry is researching appropriate models which will need to be validated. There is a need for appropriate scale experimental work to provide HSE and duty holders with a thorough understanding of how CO2 behaves during foreseeable large releases.

Containment and integrity

Whilst there are applicable general engineering standards, there is a lack of internationally recognised standards and codes of practice specifically for dense phase or supercritical CO2 plant and equipment. When designing, fabricating and maintaining plant for handling and transporting CO2 it is important that the full significance its physical properties, at the temperatures, pressures and inventories required are fully recognised and managed accordingly. Where applying standards developed for other substances including hydrocarbons, such as natural gas, extreme caution is advised as even the highest standards for many other substances may not be sufficient to ensure adequate containment for CO2 under the expected, and unexpected operating envelope(s).

No Such Thing as CLEAN COAL

I'm sorry, but coal is a fossil fuel, it is almost pure carbon, and it is the PROBLEM, not the solution, to America's energy and the world's environmental problems.

The whole intent of the devious "clean coal" marketing campaign is to justify the continued use of coal. Of course we won't be able to stop using coal all at once.

The time has come to stop wasting any more research money on trying to develop clean coal technologies, CCS, or anything that would rely on the future use of coal. Yes, coal is here and available but the energy available from renewable sources is even more widely available.... sun, tidal energy and wind energy. As an added bonus, we no longer would have to tear apart Mother Earth, pollute her land, water and air to use them.

What we need is an intensive effort - in both the public and private sectors to make this happen.

Somewhere on the web I heard it said best, "Wouldn't it be great if America could start leading on this issue, and start making things that the rest of the world wants and needs?"

America could lead this movement or we could sit back and pollute the earth by injecting CO2 FOREVER!

Which legacy would you rather leave for feature generations?

To access a web site that talks about the myth of "clean coal" click here - watch the videos, lots of GOOD STUFF there!