Septic systems should not be used immediately after floods. Drain fields will not work until underground water has receded. Septic lines may have broken during the flood (especially after the good shaking in this week’s earthquake). Whenever the water table is high or your septic drain field has been flooded, there is a risk that sewage will back up into your home. The only way to prevent this backup is to relieve pressure on the system by using it less. Basically, there is nothing you can do but wait, do not use the system if the soil is saturated and flooded. The wastewater will not be treated and will become a source of pollution, if it does not back up into your house, it will bubble up into your yard. Conserve water as much as possible while the system restores itself and the water table fails.
Do not return to your home until flood waters have receded. If there was significant flooding in your yard, water will have flooded into your septic tank through the top. The tops of septic tanks are not water tight. Flood waters entering the septic tank will have lifted the floating crust of fats and grease in the septic tank. Some of this scum may have floated and/or partially plugged the outlet tee. If the septic system backs up into the house check the tank first for outlet blockage. Remember, that septic tanks can be dangerous, methane from the bacterial digestion of waste and lack of oxygen can overwhelm you. Hire someone with the right tools to clear your outlet tee.
Do not pump the septic tank while the soil is still saturated. Furthermore, pumping out a tank that is in saturated soil may cause it to “pop out” of the ground. (Likewise, recently installed systems may “pop out” of the ground more readily than older systems because the soil has not had enough time to settle and compact.) Call a septic service company (not just a tank pumping company) and schedule an appointment in a few days. Do not use the septic system for a few days (I know) have the service company clear any outlet blockage, or blockage to the drain field, check pumps and valves and partially pump down the tank if your soils are not dry enough or fully pump the tank if the soil has drained enough. The available volume in the tank will give you several days of plumbing use if you conserve water to allow your drain field to recover. Go easy the septic system operates on the principals of settling, bacterial digestion, and soil filtration all gentle and slow natural processes that have been battered by the storm.
Sunday, August 28, 2011
Saturday, August 27, 2011
Emergency Disinfection of Your Well After the Hurricane
In an area of extensive flooding where infiltration of septic waste and chemicals can render groundwater unsafe to drink for days or even months depending on the extent of contamination and flow rate of groundwater. Essentially, the water will have to clear itself through natural attenuation (filtering by the soil and the contamination moving thorough the system). Your well may not be a safe source of water for many months after the flood, but in all likelihood it will recover. The well can become contaminated long after a storm when significant spill from up gradient can seep into the groundwater, flow down gradient and reach a well head. Waste water from malfunctioning septic tanks or chemicals seeping into the ground can contaminate the ground water even after the water was tested and found to be safe. If there was significant flooding, it is advised to respond to the immediate problem and then test the water periodically to verify the safety of drinking water.
http://water.epa.gov/aboutow/ogwdw/upload/2005_09_22_faq_fs_whattodoafteraflood_septic_eng.pdf
The most likely occurrence if you were not dead on in the path of the hurricane and submerged underwater near a trucking depot, gas station or other industrial or commercial source of chemicals is that torrential rains have infiltrated your well and you have “dirty or brownish” water from surface infiltration. This is especially true if you have a well pit. Historically, it was common practice to construct a large diameter pit around a small diameter well. The pit was intended to provide convenient access to underground water line connections below the frost line. Unfortunately, wells pits tend to be unsanitary because they literally invite drainage into the well creating a contamination hazard to the water well system. Not having a sanitary cap on a well head is another likely source of surface infiltration.
Run your hoses (away from your septic system and down slope from your well) to clear the well. Run it for an hour or so and see if it runs clear. If not let it rest for 8-12 hours and run the hoses again. Several cycles should clear the well. What we are doing is pumping out any infiltration in the well area and letting the groundwater carry any contamination away from your well. In all likelihood the well will clear of obvious discoloration. Then disinfect your well. This is an emergency procedure that will kill any bacteria for 7 to 10 days. After 7 to 10 days you need to test your well for bacteria to make sure that it is safe. Testing the well for bacteria would determine if the water were safe to drink. A bacteria test checks for the presence of total coliform bacteria and fecal coliform bacteria. These bacteria are not normally present in deeper groundwater sources. They are associated with warm-blooded animals, so they are normally found in surface water and in shallow groundwater (less than 20-40 feet deep). Most bacteria (with the exception of fecal and e-coli) are not harmful to humans, but are used as indicators of the safety of the water.
Determine what type of well you have and how to pour the bleach into the well. Some wells have a sanitary seal which must be unbolted. Some well caps have an air vent or a plug that can be removed. On bored or dug well, the entire cover can simply be lifted off to provide a space for pouring the bleach into the well. Take one gallon of non-scented household liquid bleach and carefully pour about half the bottle down into the well casing using a funnel if necessary. For a typical 6 inch diameter well you need 2 cups of regular laundry bleach for each 100 foot of well depth to achieve about 200 parts per million chlorine concentration. Wear rubber gloves, old clothes and protective glasses to protect you from the inevitable splashes, and don't forget a bucket of bleach mixed with water to wash the well cap. After the bleach has been added, run water from an outside hose into the well casing until you smell chlorine coming from the hose (depending on the depth of your well and the recharge rate, this can take more than an hour) This step is important to mix the chlorine in the well. Then turn off the outside hose. Now go into the house and one bathroom and sink at a time, turn on all cold water faucets, until the chlorine odor is detected in each faucet, then shut it off and move on to the next sink, or bathroom (if you have an automatic ice maker turn it off and dump the ice. If you have a water treatment system, switch it to bypass before turning on the indoor faucets. Once the inside system has been done, go back to the outside spigots and run the hoses until you smell chlorine coming out. Warning if you have iron bacteria in your well, your water may turn completely rust colored. Do not panic it will flush out of the system, but do not use the hot water until the water runs clear or you will have to drain the hot water tank to prevent staining.
Wait 8 to 24 hours before turning the faucets back on. You may want to run the hoses until the water runs clear. It is important not to drink, cook, bath or wash with this water during the time period it contains high amounts of chlorine whose by products are a carcinogen. After at least 8 hours, run the water into a safe area where it will not kill your lawn, your trees or plants pollute lakes, streams or septic tanks. Run the water until there is no longer a chlorine odor. Turn the water off. The system should now be disinfected, and you can now use the water for 7 to 10 days when the effects of the disinfection wear off.
Unlike public water systems, private systems are entirely unregulated; consequently, the well testing, and treatment are the voluntary responsibility of the homeowner. Virginia Master Well Owner Network (VAMWON). volunteers can help simplify understanding the components of a well and private drinking water system. The VAMWON volunteers and agents can provide information and resource links for private well owners and inform Virginians dependent on private water systems about water testing, water treatment, and system maintenance. You can find your VAMWON volunteer neighbor through this link by entering your county in the search box.
http://water.epa.gov/aboutow/ogwdw/upload/2005_09_22_faq_fs_whattodoafteraflood_septic_eng.pdf
The most likely occurrence if you were not dead on in the path of the hurricane and submerged underwater near a trucking depot, gas station or other industrial or commercial source of chemicals is that torrential rains have infiltrated your well and you have “dirty or brownish” water from surface infiltration. This is especially true if you have a well pit. Historically, it was common practice to construct a large diameter pit around a small diameter well. The pit was intended to provide convenient access to underground water line connections below the frost line. Unfortunately, wells pits tend to be unsanitary because they literally invite drainage into the well creating a contamination hazard to the water well system. Not having a sanitary cap on a well head is another likely source of surface infiltration.
Run your hoses (away from your septic system and down slope from your well) to clear the well. Run it for an hour or so and see if it runs clear. If not let it rest for 8-12 hours and run the hoses again. Several cycles should clear the well. What we are doing is pumping out any infiltration in the well area and letting the groundwater carry any contamination away from your well. In all likelihood the well will clear of obvious discoloration. Then disinfect your well. This is an emergency procedure that will kill any bacteria for 7 to 10 days. After 7 to 10 days you need to test your well for bacteria to make sure that it is safe. Testing the well for bacteria would determine if the water were safe to drink. A bacteria test checks for the presence of total coliform bacteria and fecal coliform bacteria. These bacteria are not normally present in deeper groundwater sources. They are associated with warm-blooded animals, so they are normally found in surface water and in shallow groundwater (less than 20-40 feet deep). Most bacteria (with the exception of fecal and e-coli) are not harmful to humans, but are used as indicators of the safety of the water.
Determine what type of well you have and how to pour the bleach into the well. Some wells have a sanitary seal which must be unbolted. Some well caps have an air vent or a plug that can be removed. On bored or dug well, the entire cover can simply be lifted off to provide a space for pouring the bleach into the well. Take one gallon of non-scented household liquid bleach and carefully pour about half the bottle down into the well casing using a funnel if necessary. For a typical 6 inch diameter well you need 2 cups of regular laundry bleach for each 100 foot of well depth to achieve about 200 parts per million chlorine concentration. Wear rubber gloves, old clothes and protective glasses to protect you from the inevitable splashes, and don't forget a bucket of bleach mixed with water to wash the well cap. After the bleach has been added, run water from an outside hose into the well casing until you smell chlorine coming from the hose (depending on the depth of your well and the recharge rate, this can take more than an hour) This step is important to mix the chlorine in the well. Then turn off the outside hose. Now go into the house and one bathroom and sink at a time, turn on all cold water faucets, until the chlorine odor is detected in each faucet, then shut it off and move on to the next sink, or bathroom (if you have an automatic ice maker turn it off and dump the ice. If you have a water treatment system, switch it to bypass before turning on the indoor faucets. Once the inside system has been done, go back to the outside spigots and run the hoses until you smell chlorine coming out. Warning if you have iron bacteria in your well, your water may turn completely rust colored. Do not panic it will flush out of the system, but do not use the hot water until the water runs clear or you will have to drain the hot water tank to prevent staining.
Wait 8 to 24 hours before turning the faucets back on. You may want to run the hoses until the water runs clear. It is important not to drink, cook, bath or wash with this water during the time period it contains high amounts of chlorine whose by products are a carcinogen. After at least 8 hours, run the water into a safe area where it will not kill your lawn, your trees or plants pollute lakes, streams or septic tanks. Run the water until there is no longer a chlorine odor. Turn the water off. The system should now be disinfected, and you can now use the water for 7 to 10 days when the effects of the disinfection wear off.
Unlike public water systems, private systems are entirely unregulated; consequently, the well testing, and treatment are the voluntary responsibility of the homeowner. Virginia Master Well Owner Network (VAMWON). volunteers can help simplify understanding the components of a well and private drinking water system. The VAMWON volunteers and agents can provide information and resource links for private well owners and inform Virginians dependent on private water systems about water testing, water treatment, and system maintenance. You can find your VAMWON volunteer neighbor through this link by entering your county in the search box.
Friday, August 26, 2011
Brownish or Dirty Well Water after a Storm
With Hurricane Irene approaching the east coast and potentially heading for Virginia , it seems a good time to discuss how intense rainfall associated with hurricanes can impact your drinking water well, and what you should do if your well and septic system are impacted. Brownish or Dirty water coming from the well is a common occurrence after heavy rains when surface infiltration of water can carry dirt and contaminants into a well. If your well was flooded or your water appears dirty or brownish you need to clear your well and disinfect it. (Keep reading, I will tell you how to do it.)
An impaired pump, casing systems and improper well cap can allow surface water to flow down to the groundwater. Severe flooding can undermine a pump and casing system. A properly functioning well with a sanitary well cap should not be impacted by rain even a lot of rain; however if the entire well assembly is underwater it is unlikely that even a properly constructed system could avoid some infiltration contamination. The pump system consists of the well cap, well casing, and grouting. Surface flooding or excessive rain or could flow down the casing area if the grouting is damaged or the well cap not sealed properly. Often the grouting for the casing pipe which seals the well from the surface environment was improperly installed, has become damaged over time, or in the instance of some older wells were never grouted in the first place. This of course would also allow bacteria from the surface to enter the well during heavy rainfall. Sanitary well caps and grout seal are primarily installed to prevent surface contamination, especially bacterial contamination. Bacterial contamination of groundwater wells can occur from both above and below the surface. Pollution of entire groundwater aquifers affecting many wells may occur from failing septic systems.
Most wells impacted by storms and flooding do not remain underwater, but never try to operate a submerged well. Well pumps operate on electricity, you must wait until flood water have receded and dried out to try to operate the pump. Submerged pumps can generally be tried after the flood waters have receded. Wells in pits should have the connectors carefully inspected and all components dry before operation. If the pump does not turn on call a well contractor. The pumps and the electrical systems can be damaged by sediment carried with the flood waters. It is recommended that you hire a well driller or pump contractor to clean and lubricate the pump and restore power.
Extensive flooding can allow contamination to groundwater from many wells that were not properly sealed or whose well cap and grouting were damaged by the velocity of the flood waters. The EPA states that in areas of extensive flooding any well that draws from fifty feet or less (my well for example draws from around 50 feet below grade) or that is older than 10 years is likely to be contaminated, even if they seem fine. So if you have an older well, or draw from a shallow depth, or your water appeared dirty or brown, decontaminating your well. The instructions below are standard procedure from various state department of health and the US EPA
http://water.epa.gov/drink/info/well/upload/2005_09_15_privatewells_pdfs_fs_what-to-do-after-a-flood.pdf
Run your hoses (away from your septic system and down slope from your well) to clear the well. Run it for an hour or so and see if it runs clear. If not let it rest for 8-12 hours and run the hoses again. Several cycles should clear the well. What we are doing is pumping out any infiltration in the well area and letting the groundwater carry any contamination away from your well. In all likelihood the well will clear of obvious discoloration. Then disinfect your well. This is an emergency procedure that will kill any bacteria for 7 to 10 days. After 7 to 10 days you need to test your well for bacteria to make sure that it is safe.
Determine what type of well you have and how to pour the bleach into the well. Some wells have a sanitary seal which must be unbolted. Some well caps have an air vent or a plug that can be removed. On bored or dug well, the entire cover can simply be lifted off to provide a space for pouring the bleach into the well. Take one gallon of bleach of non-scented household liquid bleach and carefully pour the bleach down into the well casing using a funnel if necessary. Wear rubber gloves, old clothes and protective glasses to protect you from the inevitable splashes. After the bleach has been added, run water from an outside hose into the well casing until you smell chlorine coming from the hose. Then turn off the outside hose. Now go into the house and one bathroom and sink at a time, turn on all cold water faucets, until the chlorine odor is detected in each faucet, then shut it off and move on to the next sink, or bathroom (if you have an automatic ice maker and water in your refrigerator dump the ice and run the water on the refrigerator also. If you have a water treatment system, switch it to bypass before turning on the indoor faucets. Once the inside system has been done, go back to the outside spigots and run the hoses until you smell chlorine coming out.
Wait 8 to 24 hours before turning the faucets back on. It is important not to drink, cook, bathe or wash with this water during the time period it contains high amounts of chlorine whose by products are a carcinogen. After at least 8 hours, run the water into a safe area where it will not kill your lawn, your trees or plants pollute lakes, streams or septic tanks. Run the water until there is no longer a chlorine odor. Turn the water off. The system should now be disinfected, and you can now use the water for 7 to 10 days when the effects of the disinfections wear off at that time test your well to make sure it is still safe to use.
An impaired pump, casing systems and improper well cap can allow surface water to flow down to the groundwater. Severe flooding can undermine a pump and casing system. A properly functioning well with a sanitary well cap should not be impacted by rain even a lot of rain; however if the entire well assembly is underwater it is unlikely that even a properly constructed system could avoid some infiltration contamination. The pump system consists of the well cap, well casing, and grouting. Surface flooding or excessive rain or could flow down the casing area if the grouting is damaged or the well cap not sealed properly. Often the grouting for the casing pipe which seals the well from the surface environment was improperly installed, has become damaged over time, or in the instance of some older wells were never grouted in the first place. This of course would also allow bacteria from the surface to enter the well during heavy rainfall. Sanitary well caps and grout seal are primarily installed to prevent surface contamination, especially bacterial contamination. Bacterial contamination of groundwater wells can occur from both above and below the surface. Pollution of entire groundwater aquifers affecting many wells may occur from failing septic systems.
Most wells impacted by storms and flooding do not remain underwater, but never try to operate a submerged well. Well pumps operate on electricity, you must wait until flood water have receded and dried out to try to operate the pump. Submerged pumps can generally be tried after the flood waters have receded. Wells in pits should have the connectors carefully inspected and all components dry before operation. If the pump does not turn on call a well contractor. The pumps and the electrical systems can be damaged by sediment carried with the flood waters. It is recommended that you hire a well driller or pump contractor to clean and lubricate the pump and restore power.
Extensive flooding can allow contamination to groundwater from many wells that were not properly sealed or whose well cap and grouting were damaged by the velocity of the flood waters. The EPA states that in areas of extensive flooding any well that draws from fifty feet or less (my well for example draws from around 50 feet below grade) or that is older than 10 years is likely to be contaminated, even if they seem fine. So if you have an older well, or draw from a shallow depth, or your water appeared dirty or brown, decontaminating your well. The instructions below are standard procedure from various state department of health and the US EPA
http://water.epa.gov/drink/info/well/upload/2005_09_15_privatewells_pdfs_fs_what-to-do-after-a-flood.pdf
Run your hoses (away from your septic system and down slope from your well) to clear the well. Run it for an hour or so and see if it runs clear. If not let it rest for 8-12 hours and run the hoses again. Several cycles should clear the well. What we are doing is pumping out any infiltration in the well area and letting the groundwater carry any contamination away from your well. In all likelihood the well will clear of obvious discoloration. Then disinfect your well. This is an emergency procedure that will kill any bacteria for 7 to 10 days. After 7 to 10 days you need to test your well for bacteria to make sure that it is safe.
Determine what type of well you have and how to pour the bleach into the well. Some wells have a sanitary seal which must be unbolted. Some well caps have an air vent or a plug that can be removed. On bored or dug well, the entire cover can simply be lifted off to provide a space for pouring the bleach into the well. Take one gallon of bleach of non-scented household liquid bleach and carefully pour the bleach down into the well casing using a funnel if necessary. Wear rubber gloves, old clothes and protective glasses to protect you from the inevitable splashes. After the bleach has been added, run water from an outside hose into the well casing until you smell chlorine coming from the hose. Then turn off the outside hose. Now go into the house and one bathroom and sink at a time, turn on all cold water faucets, until the chlorine odor is detected in each faucet, then shut it off and move on to the next sink, or bathroom (if you have an automatic ice maker and water in your refrigerator dump the ice and run the water on the refrigerator also. If you have a water treatment system, switch it to bypass before turning on the indoor faucets. Once the inside system has been done, go back to the outside spigots and run the hoses until you smell chlorine coming out.
Wait 8 to 24 hours before turning the faucets back on. It is important not to drink, cook, bathe or wash with this water during the time period it contains high amounts of chlorine whose by products are a carcinogen. After at least 8 hours, run the water into a safe area where it will not kill your lawn, your trees or plants pollute lakes, streams or septic tanks. Run the water until there is no longer a chlorine odor. Turn the water off. The system should now be disinfected, and you can now use the water for 7 to 10 days when the effects of the disinfections wear off at that time test your well to make sure it is still safe to use.
Wednesday, August 24, 2011
Brownish or Dirty Well Water after the Earthquake
Brownish or Dirty water is a common occurrence after earthquakes. An earthquake can cause water wells to become turbid, which is when the water is cloudy or more commonly dirty looking, and well water quality have become degraded as a result of earthquakes. Earthquakes can affect the water level in your well. To see if your well has been impacted, you will have to empty your pressure tank and see what pumps out of the well. Turbidity could move through the system and pass in a short period or not depending on the specific geology, soil type and hydro geology. Aquifers are water-bearing subsurface soil and rock formations that can be effected by seismic activity. In bedrock formations, for instance, the well will be drilled until it hits a fracture or crevice that holds water. Earthquake shocks can increase the permeability of the aquifer rocks and cause the water level to fall with gravity through the more permeable materials and the water will fall to a lower level leaving the well dry. http://pubs.usgs.gov/fs/fs-096-03/
There are also plumbing problems that can cause brownish water and do not forget that earthquakes can cause the fittings to the septic tank to fail and a well could become impacted by a leaking septic tank (or several leaking tanks in the neighborhood). First, check your plumbing, check the screens and aerators in your sinks and then verify that both the hot water and cold water are both discolored. If the hot water only is discolored then the problem might be with rust the hot water heater that was shaken loose, simply drain it. After determining that the brown water is coming from the cold water tap also, it is still possible that there is rust in the plumbing fixtures or the piping, but it would typically manifest in only one sink or tub and not uniformly throughout the house (unless the rust is in the main water pipe from the well).
After rust in the household fixtures there are four likely causes for well water to be brown or brownish, surface infiltration, soil fines having shaken loose are being pulled into the well, water level dropping or iron (and/or manganese) in the water. Earthquakes can cause a change in water, either by loosening fine grains of silt and soil, loosening minerals or lowering the water level. According the US Geological Survey there is no rhyme or reason to which wells will be impacted by an earthquake, but time might restore your well. Run your well thought your hoses to the yard for a couple of hours. Let the well rest for a couple of hours and then run the hoses again. See if there is sediment or only color with the water. If no sediment appears, you probably are only pumping fines and the well should clear after several rounds of pumping and rest. If you are pumping sediment, it might be a loss of water level. Wait and see if the well recovers. According to David Helms of the US Geological Survey in Richmond, who is still analyzing the data, USGS monitoring wells have shown significant impact. The example he gave me was the Reston well which experienced a sudden drop in groundwater level yesterday and though it recovered by this morning, the water level was lower than the pre-event level. It is unknown if the groundwater level will recover fully and a lowering of the water in a well can cause the well to basically pump mud.
Surface infiltration of water is due to impaired pump and casing system, but is unlikely to be the cause of sudden brownish water after an earthquake. A leaking septic system could also impact water quality. Testing the well for bacteria would determine if the water were safe to drink. A bacteria test checks for the presence of total coliform bacteria and fecal coliform bacteria. These bacteria are not normally present in deeper groundwater sources. They are associated with warm-blooded animals, so they are normally found in surface water and in shallow groundwater(less than 20-40 feet deep). Most bacteria (with the exception of fecal and e-coli) are not harmful to humans, but are used as indicators of the safety of the water. An inspection of the well and pump system might visually locate any obvious flaws but the presence of coliform surface bacteria would certainly identify where to begin looking. The most likely source of brown water after the earthquake is from the well itself. It is typical in Virginia not to have well casing beyond 40-50 feet deep. The Balls Bluff Siltstone and red clay common to this area does not typically need a casing. The most common modern well installation is to have a pump that installed in the well and looks a little like an outboard motor on a stick. While the most common source of brown water is soil fines shaken loose in the earthquake, there can be other causes. Changes in water level or supply could result in the pump pulling up a bit of mud or the pump could have wracked a bit and is hitting the side of the well hole. So that water that suddenly turns brown may indicate a problem with the well structure or water level. Turn on your hoses and put your hands on the well cap, if you feel any vibrations or hear a sound you probably have a pump problem. Also listen at the well pipe into the house.
The final source of brown water is iron (and/or manganese) in the water. As rain falls or snow melts on the land surface, and water seeps through iron-bearing soil and rock, iron can be dissolved into the water. In some cases, iron can also result from corrosion of iron or steel well casing or water pipes. Iron can occur in water in a number of different forms. Iron is harmless, but can affect taste and use of water. The earthquake might have shaken loose minerals or rust in your system. This source of brownish color might pass through the system like soil fines, but could require a greensand filter.
There are also plumbing problems that can cause brownish water and do not forget that earthquakes can cause the fittings to the septic tank to fail and a well could become impacted by a leaking septic tank (or several leaking tanks in the neighborhood). First, check your plumbing, check the screens and aerators in your sinks and then verify that both the hot water and cold water are both discolored. If the hot water only is discolored then the problem might be with rust the hot water heater that was shaken loose, simply drain it. After determining that the brown water is coming from the cold water tap also, it is still possible that there is rust in the plumbing fixtures or the piping, but it would typically manifest in only one sink or tub and not uniformly throughout the house (unless the rust is in the main water pipe from the well).
After rust in the household fixtures there are four likely causes for well water to be brown or brownish, surface infiltration, soil fines having shaken loose are being pulled into the well, water level dropping or iron (and/or manganese) in the water. Earthquakes can cause a change in water, either by loosening fine grains of silt and soil, loosening minerals or lowering the water level. According the US Geological Survey there is no rhyme or reason to which wells will be impacted by an earthquake, but time might restore your well. Run your well thought your hoses to the yard for a couple of hours. Let the well rest for a couple of hours and then run the hoses again. See if there is sediment or only color with the water. If no sediment appears, you probably are only pumping fines and the well should clear after several rounds of pumping and rest. If you are pumping sediment, it might be a loss of water level. Wait and see if the well recovers. According to David Helms of the US Geological Survey in Richmond, who is still analyzing the data, USGS monitoring wells have shown significant impact. The example he gave me was the Reston well which experienced a sudden drop in groundwater level yesterday and though it recovered by this morning, the water level was lower than the pre-event level. It is unknown if the groundwater level will recover fully and a lowering of the water in a well can cause the well to basically pump mud.
Surface infiltration of water is due to impaired pump and casing system, but is unlikely to be the cause of sudden brownish water after an earthquake. A leaking septic system could also impact water quality. Testing the well for bacteria would determine if the water were safe to drink. A bacteria test checks for the presence of total coliform bacteria and fecal coliform bacteria. These bacteria are not normally present in deeper groundwater sources. They are associated with warm-blooded animals, so they are normally found in surface water and in shallow groundwater(less than 20-40 feet deep). Most bacteria (with the exception of fecal and e-coli) are not harmful to humans, but are used as indicators of the safety of the water. An inspection of the well and pump system might visually locate any obvious flaws but the presence of coliform surface bacteria would certainly identify where to begin looking. The most likely source of brown water after the earthquake is from the well itself. It is typical in Virginia not to have well casing beyond 40-50 feet deep. The Balls Bluff Siltstone and red clay common to this area does not typically need a casing. The most common modern well installation is to have a pump that installed in the well and looks a little like an outboard motor on a stick. While the most common source of brown water is soil fines shaken loose in the earthquake, there can be other causes. Changes in water level or supply could result in the pump pulling up a bit of mud or the pump could have wracked a bit and is hitting the side of the well hole. So that water that suddenly turns brown may indicate a problem with the well structure or water level. Turn on your hoses and put your hands on the well cap, if you feel any vibrations or hear a sound you probably have a pump problem. Also listen at the well pipe into the house.
The final source of brown water is iron (and/or manganese) in the water. As rain falls or snow melts on the land surface, and water seeps through iron-bearing soil and rock, iron can be dissolved into the water. In some cases, iron can also result from corrosion of iron or steel well casing or water pipes. Iron can occur in water in a number of different forms. Iron is harmless, but can affect taste and use of water. The earthquake might have shaken loose minerals or rust in your system. This source of brownish color might pass through the system like soil fines, but could require a greensand filter.
Your Water Well After the Earthquake
Surprise, Virginia just had an intra plate earthquake measuring a 5.8 on the Richter scale. It has been well documented that earthquakes can have significant effects on water wells. Hydro geologic responses to earthquakes have been known for decades, and have occurred both close to, and thousands of miles from earthquake epicenters. The US Geological Survey has a national network of monitoring wells to study the impacts of earthquakes on groundwater and water wells. An earthquake can cause water wells to become turbid, which is when the water is cloudy or more commonly dirty looking, wells have gone dry or flow has increased, discharge of ground water to streams has increased and new springs have formed, and well water quality have become degraded as a result of earthquakes. Earthquakes can affect your drinking water well. http://pubs.usgs.gov/fs/fs-096-03/
Aquifers which consist of unconsolidated materials can compact, or become almost liquefied as a result of the seismic energy moving though them during the earthquake, in a process called liquefaction. This results in a compression of the soils and a loss of storage for groundwater, and subsidence on the ground’s surface. Aquifers are water-bearing subsurface soil and rock formations that can be effected by seismic activity. In bedrock formations, for instance, the well will be drilled until it hits a fracture or crevice that holds water. Earthquake shocks can increase the permeability of the aquifer rocks and cause the water level to fall with gravity through the more permeable materials and the water will fall to a lower level leaving the well dry.
The most common type of observed ground-water response is an instantaneous water-level fall or rise and can occur near or far from the epicenter of the quake without significant change to the rock formation. Recovery to the pre-earthquake water level can be so rapid as to be almost unnoticeable, or it may take as long as several days or months. Water level changes can be large enough to make a well flow to the land surface, or render a well dry. In 1998 there was an earthquake in northwestern Pennsylvania that caused about 120 local household drinking water wells to go dry within 3 months after the earthquake, they never recovered. Very large earthquakes even at great distances can also cause the water table to temporarily rise and fall when the seismic long waves pass through the state and this is the most common type of groundwater response. The 2002 earthquake in Alaska caused a 2-foot water-level rise in a well in Wisconsin, more than a thousand miles from the epicenter.
The shaking associated with an earthquake may cause sand to plug a well screen, and thus reduce the volume of water that can be pumped. Conversely, the shaking can dislodge sand plugging a well screen and cause an increase in the volume of water that can be pumped from the well. In Virginia where well casings typically extend only 50 feet below grade, the shaking or oscillation of the earth may dislodge sand or dirt within the water table that can be captured by the pump. In some cases the well returns to its normal state and the loosened particles can be flushed out of the system but in others the well needs to be serviced to restore former production volume. In an interesting report from the Geological Survey of Japan and the Japanese National Institute of Advanced Industrial Science and Technology (AIST) that groundwater anomalies were recorded several days before the 1946 Nankai earthquake. The reported phenomena were turbid groundwater, decreases of groundwater level or hot spring discharge.
According the US Geological Survey the exact mechanism linking hydro geologic changes and earthquakes is not fully understood. Because an earthquake can cause shifts in the earth and water bearing soil and rock formations, groundwater used for drinking and the private drinking water wells can be affected. According to David Helms of the US Geological Survey in Richmond, who is still analyzing the data, USGS monitoring wells have shown significant impact. The example he gave me was the Reston well which experienced a sudden drop in groundwater level yesterday and though it recovered by this morning, the water level was lower than the pre-event level. It is unknown if the groundwater level will recover fully. Well water can also become cloudy or take on a different color, smell and feel. The water can become contaminated with dirt, minerals and other solids, as well as bacteria due to damage to the casing and grouting. To see if your well has been impacted, you will have to empty your pressure tank and see what pumps out of the well. Turbidity could move through the system and pass in a short period or not depending on the specific geology, soil type and hydro geology. However, if there are any indications of impact the water should be tested to ensure it is still potable.
Aquifers which consist of unconsolidated materials can compact, or become almost liquefied as a result of the seismic energy moving though them during the earthquake, in a process called liquefaction. This results in a compression of the soils and a loss of storage for groundwater, and subsidence on the ground’s surface. Aquifers are water-bearing subsurface soil and rock formations that can be effected by seismic activity. In bedrock formations, for instance, the well will be drilled until it hits a fracture or crevice that holds water. Earthquake shocks can increase the permeability of the aquifer rocks and cause the water level to fall with gravity through the more permeable materials and the water will fall to a lower level leaving the well dry.
The most common type of observed ground-water response is an instantaneous water-level fall or rise and can occur near or far from the epicenter of the quake without significant change to the rock formation. Recovery to the pre-earthquake water level can be so rapid as to be almost unnoticeable, or it may take as long as several days or months. Water level changes can be large enough to make a well flow to the land surface, or render a well dry. In 1998 there was an earthquake in northwestern Pennsylvania that caused about 120 local household drinking water wells to go dry within 3 months after the earthquake, they never recovered. Very large earthquakes even at great distances can also cause the water table to temporarily rise and fall when the seismic long waves pass through the state and this is the most common type of groundwater response. The 2002 earthquake in Alaska caused a 2-foot water-level rise in a well in Wisconsin, more than a thousand miles from the epicenter.
The shaking associated with an earthquake may cause sand to plug a well screen, and thus reduce the volume of water that can be pumped. Conversely, the shaking can dislodge sand plugging a well screen and cause an increase in the volume of water that can be pumped from the well. In Virginia where well casings typically extend only 50 feet below grade, the shaking or oscillation of the earth may dislodge sand or dirt within the water table that can be captured by the pump. In some cases the well returns to its normal state and the loosened particles can be flushed out of the system but in others the well needs to be serviced to restore former production volume. In an interesting report from the Geological Survey of Japan and the Japanese National Institute of Advanced Industrial Science and Technology (AIST) that groundwater anomalies were recorded several days before the 1946 Nankai earthquake. The reported phenomena were turbid groundwater, decreases of groundwater level or hot spring discharge.
According the US Geological Survey the exact mechanism linking hydro geologic changes and earthquakes is not fully understood. Because an earthquake can cause shifts in the earth and water bearing soil and rock formations, groundwater used for drinking and the private drinking water wells can be affected. According to David Helms of the US Geological Survey in Richmond, who is still analyzing the data, USGS monitoring wells have shown significant impact. The example he gave me was the Reston well which experienced a sudden drop in groundwater level yesterday and though it recovered by this morning, the water level was lower than the pre-event level. It is unknown if the groundwater level will recover fully. Well water can also become cloudy or take on a different color, smell and feel. The water can become contaminated with dirt, minerals and other solids, as well as bacteria due to damage to the casing and grouting. To see if your well has been impacted, you will have to empty your pressure tank and see what pumps out of the well. Turbidity could move through the system and pass in a short period or not depending on the specific geology, soil type and hydro geology. However, if there are any indications of impact the water should be tested to ensure it is still potable.
Monday, August 22, 2011
Depleting our Groundwater Supplies
Whenever you pump water from a well it has to be balanced by a loss of water from storage in the groundwater aquifer. Groundwater is recharged from rain and sources of surface infiltration. The response of a groundwater aquifer to pumping depends on whether the aquifer is confined or unconfined, how much water is pumped and the geology of the area. If too much water is pumped, water tables can drop in unconfined aquifers, water pressure fall in confined aquifers, surface water and ecology could be impacted and in some locations with fine grained soils compaction and subsidence can take place. The U.S. Geological Survey’s (USGS) Groundwater Resources Program is conducting large-scale multiyear regional studies of groundwater availability in the United States. The USGS has found that the volume of groundwater stored in the earth is decreasing in many regions of the United States. The water level is falling in many areas and if this continues we could deplete our groundwater. The extent of groundwater level declines across the United States has not been monitored before now. The most recent effort to summarize the declines in artesian water levels or water tables was in 1983. Since that time our demands on the groundwater have increased and our understanding of groundwater has improved. It is now very clear we are running a groundwater deficit.
http://pubs.usgs.gov/circ/1323/pdf/Circular1323_book_508.pdf
Although humans have been digging wells and tunnels for water supply for thousands of years, extensive use of ground water is relatively recent, and coincides with more effective drilling and pumping technologies during the past 75 years. The USGS is trying to determine how much ground water we have, how fast groundwater supplies are running out and where climate and human development might combine to create critical problem areas. Large-scale development and exploitation of ground-water resources and the accompanying declines in ground-water levels and other effects of pumping has led to concerns about the future availability of ground water to meet domestic, agricultural, industrial, and environmental needs. Water availability and how we manage water resources will determine the future of our nation.
http://water.usgs.gov/ogw/gwrp/activities/overview-pubs.html
During the past century, several ground-water assessments have been completed by the USGS. These national and regional evaluations have increased our knowledge about roundwater resources and groundwater in general. Our understanding of groundwater and its how it is connected to surface-water systems has expanded and new methods and technologies for resource assessment have been developed and with it the issues of concern have changed. Environmental decision making has grown more complex with increased knowledge about groundwater and its role in estuaries. Water is necessary for human use and environmental protection and preservation.
The USGS has been using long-term groundwater monitoring data, combined with groundwater models, to improve our understanding of the storage and flow of groundwater. This task is quite difficult, groundwater is not easily observed and not all the water pumped is consumed. When water is pumped from the ground and used, the water molecules are not destroyed; the water is simply moved to different places. Consumed water is assumed to be evaporated, transpired, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment. The rest of the water goes back into the environment, such as sewage disposal into streams, septic leaching fields back into the ground and additional recharge from excess irrigation. Even the water consumed, however, is not really lost; it goes into the atmosphere or into products or living tissue. When analyzing the amount of ground-water available, it is important to consider consumptive use and return flow as well as withdrawals.
The growing population and the effects of recent droughts have made the need for an updated status on the availability of the groundwater necessary. For over 60 years the USGS has worked with state and local agencies to compile estimates of groundwater and surface-water withdrawals for the Nation at 5-year intervals. Some water-use data, such as public supply for household uses and withdrawals by some industrial users, are obtained by direct measurement. Other permitted uses are estimated as the amount reported or allowed by permit. Many uses, such as private drinking water wells, irrigation, and some industries, are estimated. This data has been used to see how groundwater demand has changed over time. This information has been combined with water level measurement and monitoring to develop computer models and tools to forecast groundwater aquifer response to human and environmental stressors like groundwater pumping, diversion of surface water, irrigation and droughts.
The USGS has compiled all this data to try and get an idea of what our water resources are and what our demands for groundwater are. Groundwater provides half our drinking water and is essential to the vitality of agriculture and industry, as well as to the health of rivers, wetlands, and estuaries throughout the country. We need to have a sustainable water budget for the nation’s groundwater aquifer systems; however, sustainable budgets do not appear to be our nation’s strong point. This is compounded by the fact that ground-water management decisions in the United States are made at a local level. Many aquifer systems cross these political boundaries, making appropriate management extremely difficult even within our own nation.
http://pubs.usgs.gov/circ/1323/pdf/Circular1323_book_508.pdf
Although humans have been digging wells and tunnels for water supply for thousands of years, extensive use of ground water is relatively recent, and coincides with more effective drilling and pumping technologies during the past 75 years. The USGS is trying to determine how much ground water we have, how fast groundwater supplies are running out and where climate and human development might combine to create critical problem areas. Large-scale development and exploitation of ground-water resources and the accompanying declines in ground-water levels and other effects of pumping has led to concerns about the future availability of ground water to meet domestic, agricultural, industrial, and environmental needs. Water availability and how we manage water resources will determine the future of our nation.
http://water.usgs.gov/ogw/gwrp/activities/overview-pubs.html
During the past century, several ground-water assessments have been completed by the USGS. These national and regional evaluations have increased our knowledge about roundwater resources and groundwater in general. Our understanding of groundwater and its how it is connected to surface-water systems has expanded and new methods and technologies for resource assessment have been developed and with it the issues of concern have changed. Environmental decision making has grown more complex with increased knowledge about groundwater and its role in estuaries. Water is necessary for human use and environmental protection and preservation.
The USGS has been using long-term groundwater monitoring data, combined with groundwater models, to improve our understanding of the storage and flow of groundwater. This task is quite difficult, groundwater is not easily observed and not all the water pumped is consumed. When water is pumped from the ground and used, the water molecules are not destroyed; the water is simply moved to different places. Consumed water is assumed to be evaporated, transpired, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment. The rest of the water goes back into the environment, such as sewage disposal into streams, septic leaching fields back into the ground and additional recharge from excess irrigation. Even the water consumed, however, is not really lost; it goes into the atmosphere or into products or living tissue. When analyzing the amount of ground-water available, it is important to consider consumptive use and return flow as well as withdrawals.
The growing population and the effects of recent droughts have made the need for an updated status on the availability of the groundwater necessary. For over 60 years the USGS has worked with state and local agencies to compile estimates of groundwater and surface-water withdrawals for the Nation at 5-year intervals. Some water-use data, such as public supply for household uses and withdrawals by some industrial users, are obtained by direct measurement. Other permitted uses are estimated as the amount reported or allowed by permit. Many uses, such as private drinking water wells, irrigation, and some industries, are estimated. This data has been used to see how groundwater demand has changed over time. This information has been combined with water level measurement and monitoring to develop computer models and tools to forecast groundwater aquifer response to human and environmental stressors like groundwater pumping, diversion of surface water, irrigation and droughts.
The USGS has compiled all this data to try and get an idea of what our water resources are and what our demands for groundwater are. Groundwater provides half our drinking water and is essential to the vitality of agriculture and industry, as well as to the health of rivers, wetlands, and estuaries throughout the country. We need to have a sustainable water budget for the nation’s groundwater aquifer systems; however, sustainable budgets do not appear to be our nation’s strong point. This is compounded by the fact that ground-water management decisions in the United States are made at a local level. Many aquifer systems cross these political boundaries, making appropriate management extremely difficult even within our own nation.
Thursday, August 18, 2011
Groundwater Impacts from Geological Events
The US Geological Survey has been studying the impacts of earthquakes on groundwater. For years they have been monitoring groundwater wells to observe any noticeable changes coinciding with earthquakes. The most common effect on groundwater from earthquakes is an instantaneous water-level increase or decrease. Recovery to the pre-earthquake water level can be so rapid that no change is detected. http://va.water.usgs.gov/earthquakes/index.htm
These spikes have been observed to occur thousands of miles from the earthquake epicenters. Most of the time, these spikes are transitory with no lasting consequences for groundwater supply or quality. In rare cases the water supply is permanently changed- wells have dried up, some wells have seen flow increase, springs have been created and springs have dried up. Groundwater quality has also been observed to change as a result of earthquakes. The response is not predictable and surprisingly far reaching. The USGS monitoring well in Christiansburg, Virginia has been observed to react to earthquakes over 10,000 miles away.
Responses of water levels in wells to earthquakes are influenced by many factors including the magnitude and depth of the earthquake, distance from the epicenter, and the type of rock that surrounds the groundwater. The depth of the well, whether the aquifer is confined or unconfined, and well construction also influence the degree of water-level fluctuations in wells in response to seismic waves. Some aquifers may even act as resonators, which may amplify the response. However, there is not a complete understanding of mechanism of impacting groundwater wells and how a well will be impacted. http://va.water.usgs.gov/Gw_FS_2008.pdf
In hydraulic fracking on average 2.8 million gallons of chemicals and water is pumped into the shale formation at 9,000 pounds per square inch and literally cracks the shale or breaks open existing cracks and allows the trapped natural gas to flow. While geologists and engineers believe that there is little risk that the fracking “water,” a mix chemicals and water, will somehow infiltrate through the shale and the thousands of feet to reach the groundwater reserves though a fissure created by the fracking, there are other routes of contamination and impact.
Much is not known about the impacts of hydraulic fracturing. Shale fracking is usually at depths of approximately 9,500 feet well below the drinking water aquifer. Horizontal drilling and multi-stage fracking are used to collect this gas, which differs from the hydraulic fracturing techniques historically used. Modern fracking is not only deeper, it also uses substantially more freshwater an average of 2.8 million gallons rather than the up to 100,000 gallons and much lower pressure used in older forms of fracking. There are many unknowns with respect to the environmental and long-term impacts on groundwater supply and hydrology. Currently, the US Environmental Protection Agency (EPA) is studying the impact of hydraulic fracturing on water resources, but they are focusing on the potential to directly pollute the drinking aquifer, not looking at potential changes in the groundwater hydrology.
Millions of gallons of water are used to fracture each well. Using fresh water to fracture a well is an unsustainable use of water resources, when you consider that there are reported to be over 5,000 permits to drill hydraulic fracturing wells next year in Pennsylvania alone. That would be 14 billion gallons of water withdrawn from the water table and injected into the shale. Once the fracking process is complete, anywhere from 30-60% of the fracking water comes back to the surface as flowback. This means that each well produces a million or more gallons of wastewater which will have to be treated and disposed of. Land application, untreated release to rivers, processing through waste water treatment plants are inappropriate methods for disposal and potential sources of pollution to our water supplies. The impact and fate of the 40-70% of fracking water that does not flowback is unknown.
Errors in natural gas well construction or spills during injection can occur and lead to drinking water contamination. Fluids can spill before they are injected and fluids recovered from fracturing can contaminate surface waters. Additionally, drilling into the subsurface can create pathways for fracking fluids or natural gas to find its way into water supplies, if grouting isn’t properly done and the well properly constructed. It should be noted also that the horizontal sections of the wells are not cased in cement and, introduces a potential point where contamination can originate. Hydraulic fracturing should continue slowly. A limited number of wells should be installed with careful monitoring of local and regional groundwater supplies as well as verification of proper well construction and wastewater recycling.
These spikes have been observed to occur thousands of miles from the earthquake epicenters. Most of the time, these spikes are transitory with no lasting consequences for groundwater supply or quality. In rare cases the water supply is permanently changed- wells have dried up, some wells have seen flow increase, springs have been created and springs have dried up. Groundwater quality has also been observed to change as a result of earthquakes. The response is not predictable and surprisingly far reaching. The USGS monitoring well in Christiansburg, Virginia has been observed to react to earthquakes over 10,000 miles away.
Responses of water levels in wells to earthquakes are influenced by many factors including the magnitude and depth of the earthquake, distance from the epicenter, and the type of rock that surrounds the groundwater. The depth of the well, whether the aquifer is confined or unconfined, and well construction also influence the degree of water-level fluctuations in wells in response to seismic waves. Some aquifers may even act as resonators, which may amplify the response. However, there is not a complete understanding of mechanism of impacting groundwater wells and how a well will be impacted. http://va.water.usgs.gov/Gw_FS_2008.pdf
In hydraulic fracking on average 2.8 million gallons of chemicals and water is pumped into the shale formation at 9,000 pounds per square inch and literally cracks the shale or breaks open existing cracks and allows the trapped natural gas to flow. While geologists and engineers believe that there is little risk that the fracking “water,” a mix chemicals and water, will somehow infiltrate through the shale and the thousands of feet to reach the groundwater reserves though a fissure created by the fracking, there are other routes of contamination and impact.
Much is not known about the impacts of hydraulic fracturing. Shale fracking is usually at depths of approximately 9,500 feet well below the drinking water aquifer. Horizontal drilling and multi-stage fracking are used to collect this gas, which differs from the hydraulic fracturing techniques historically used. Modern fracking is not only deeper, it also uses substantially more freshwater an average of 2.8 million gallons rather than the up to 100,000 gallons and much lower pressure used in older forms of fracking. There are many unknowns with respect to the environmental and long-term impacts on groundwater supply and hydrology. Currently, the US Environmental Protection Agency (EPA) is studying the impact of hydraulic fracturing on water resources, but they are focusing on the potential to directly pollute the drinking aquifer, not looking at potential changes in the groundwater hydrology.
Millions of gallons of water are used to fracture each well. Using fresh water to fracture a well is an unsustainable use of water resources, when you consider that there are reported to be over 5,000 permits to drill hydraulic fracturing wells next year in Pennsylvania alone. That would be 14 billion gallons of water withdrawn from the water table and injected into the shale. Once the fracking process is complete, anywhere from 30-60% of the fracking water comes back to the surface as flowback. This means that each well produces a million or more gallons of wastewater which will have to be treated and disposed of. Land application, untreated release to rivers, processing through waste water treatment plants are inappropriate methods for disposal and potential sources of pollution to our water supplies. The impact and fate of the 40-70% of fracking water that does not flowback is unknown.
Errors in natural gas well construction or spills during injection can occur and lead to drinking water contamination. Fluids can spill before they are injected and fluids recovered from fracturing can contaminate surface waters. Additionally, drilling into the subsurface can create pathways for fracking fluids or natural gas to find its way into water supplies, if grouting isn’t properly done and the well properly constructed. It should be noted also that the horizontal sections of the wells are not cased in cement and, introduces a potential point where contamination can originate. Hydraulic fracturing should continue slowly. A limited number of wells should be installed with careful monitoring of local and regional groundwater supplies as well as verification of proper well construction and wastewater recycling.
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