2018 Prince William County Wells

On May 8th 2018 we had the results meeting for the 2018 Prince William County Water Clinic. What we tested for were mostly the naturally occurring contaminants and common sources of contamination: a poorly sealed well or a nearby leaking septic system, or indications of plumbing system corrosion. These are the most common contaminants that effect drinking water wells. The chart below shows what was found in the 114 samples tested in Prince William County in April 2018.

 In order to determine if treatment is necessary, water test results should be compared to a standard. The standard we use is the U.S.EPA Safe Drinking Water Act (SDW) limits. Though private wells do not fall under the regulatory authority of the U.S. Environmental Protection Agency (EPA) or the Safe Drinking Water Act, the SDW act has primary and secondary drinking water standards that we use for comparison. Primary standards are ones that can impact health and from the tested substances include: coliform bacteria, E. coli bacteria, nitrate, lead, and arsenic. Secondary standards impact taste or the perceived quality of the water.

The 2018 Prince William County water clinic found that almost 22% of the wells tested present for coliform bacteria. Coliform bacteria are not a health threat itself, it is used to indicate other bacteria that may be present and identify that a well is not properly sealed from surface bacteria. The federal standard for coliform bacteria is zero, but the federal standard allows that up to 5% of samples can test positive for coliform during a month.

One home tested positive for E coli. Fecal coliform and E. coli are bacteria whose presence indicates that the water is contaminated with human or animal wastes. Disease-causing microbes (pathogens) in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. These pathogens may pose a special health risk for infants, young children, and those with compromised immune systems. However, people can drink water contaminated with fecal bacteria and not notice.

If your water is contaminated with coliform but not fecal coliform or E. coli, then you have a nuisance bacteria problem and the source may be infiltration from the surface from rain or snow melt. Typical causes are improperly sealed well cap, well repairs performed without disinfecting the well, failed grouting or surface drainage to the well. If your well had coliform bacteria present you should shock chlorinate the well, repack the soil around the well pipe to flow away from the well and replace the well cap. Then after at least two weeks and the next big rainstorm retest the well for coliform. If coliform bacteria is still present then a long-term treatment should be implemented: using UV light, ozonation, or chlorine for continuous disinfection. These systems can cost up to $2,000 installed.

If you have fecal coliform in the well or E. coli, your well is being impacted by human or animal waste and you are drinking dilute sewage. If there is not a nearby animal waste composting facility, then you are probably drinking water from a failed septic system- yours or your nearest neighbors or in some older areas a leaking sewer line. To solve this problem you need to fix or replace the septic system that is causing the contamination, replace the well or install a disinfection and filtration system. Disinfection does not kill Giardia or Cryptosporidium, two microscopic parasites that can be found in groundwater that has been impacted by surface water or sewage. Both parasites produce cysts that cause illness and sometimes death.

Membrane filtration is the usual treatment for these parasites- a one micron or smaller membrane is required for this. There are new filter systems that combine carbon and one micron or smaller membrane a a special filter designed for this purpose. To ensure that a filter removes Cryptosporidium, you can look for "NSF 53" or "NSF 58" and the words "cyst reduction" or "cyst removal." Reverse osmosis can also accomplish parasite removal, but typically only treats one sink rather than a whole house, wastes a lot of water, and if your water is at all hard requires a water softening system.

The failing septic systems can often be identified by using tracer dyes. While continuous disinfection will work to protect you from fecal bacteria and E. coli, be aware that if your well is being impacted by a septic system, then the well water might also have present traces of all the chemicals and substances that get poured down the drain. Long term treatment for disinfection, and micro-filtration should be implemented: using UV light, ozonation, or chlorine for continuous disinfection, carbon filtration, and anything that is used for drinking should be further treated with a reverse osmosis systems or micro membrane system that works by using pressure to force water through a semi-permeable membrane. Large quantities of wastewater are produced by reverse osmosis systems and need to bypass the septic system or they will overwhelm that system creating more groundwater problems. Reverse osmosis systems produce water very slowly, a pressurized storage tank and special faucet needs to be installed so that water is available to meet the demand for drinking and cooking.

Nitrate can contaminate well water from fertilizer use; leaking from septic tanks, sewage and erosion of natural deposits. None of the wells in our group of 114 samples had nitrate levels above the MCL. The MCL for nitrate is 10 mg/L. Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill from blue-baby syndrome and, if untreated, may die. Symptoms include shortness of breath and a blue ting to the skin common in blue-baby syndrome. The NO3 dissolves and moves easily through soil which varies seasonally and over time as plants use up the nitrate over the summer. Testing in the spring will usually produce the highest levels. Nitrate may indicate contamination from septic tanks, but do not boil the water- boiling water reduces the water and actually INCREASES the concentration of nitrates. Reverse osmosis, or ion exchange is necessary to control the nitrate. None of the wells tested exceeded the MCL.

This year we had 7% of homes have first draw lead levels above the SDWA maximum contaminant level of 0.015 Mg/L. After the flushing the tap for at least one minute none had lead levels above the 0.15 mg/L level; however, many scientists do not believe that any level of lead is safe to drink over an extended period of time. In the homes that had elevated lead in the first draw, it tends to be negatively correlated with pH values and copper pipes. Houses built before 1988 when the ban on lead went into effect and have low pH water typically have higher lead concentrations. Lead leaches into water primarily as a result of corrosion of plumbing and well components, but can also result from flaking of scale from brass fittings and well components unrelated to corrosion and corrosion control techniques such as adjusting pH or alkalinity that are commonly used to neutralize aggressive water will not work in those cases. For most instances, though, a neutralizing filter and lead removing activated carbon filters can be used to remove lead. Recently, some home water treatment companies are offering in home treatment systems that neutralize the water and add orthophosphate other phosphate solution to coat the piping to prevent further corrosion. It should work, but I have never seen such a home system and am not aware of any testing.

Iron and manganese are naturally occurring elements commonly found in groundwater in this part of the country. 11.4% of the wells tested exceed the iron standard and 3.5% exceeded the manganese standard. At naturally occurring levels iron and manganese do not present a health hazard. However, their presence in well water can cause unpleasant taste, staining and accumulation of mineral solids that can clog water treatment equipment and plumbing and discolored water. The standard Secondary Maximum Contaminant Level (SMCL) for iron is 0.3 milligrams per liter (mg/L or ppm) and 0.05 mg/L for manganese. This level of iron and manganese can be detected by taste, smell or appearance. In addition, some types of bacteria react with soluble forms of iron and manganese and form persistent bacterial contamination in a well, water system and any treatment systems. These organisms change the iron and manganese from a soluble form into a less soluble form, thus causing precipitation and accumulation of black or reddish brown gelatinous material (slime). Masses of mucous, iron, and/or manganese can clog plumbing and water treatment equipment.

All systems of removing iron and manganese essentially involve oxidation of the soluble form or killing and removal of the iron bacteria. When the total combined iron and manganese concentration is less than 15 mg/l, an oxidizing filter is the recommended solution. An oxidizing filter supplies oxygen to convert ferrous iron into a solid form which can be filtered out of the water. Higher concentrations of iron and manganese can be treated with an aeration and filtration system. This system is not effective on water with iron/ manganese bacteria, but is very effective on soluble iron and manganese so you need to do further testing to determine what type of iron/manganese you have before you install a treatment system. Water softeners can remove low levels of iron and are widely sold for this purpose because they are very profitable, but are not recommended for just this purpose. Chemical oxidation can be used to remove high levels of dissolved or oxidized iron and manganese as well as treat the presence of iron/manganese (or even sulfur) bacteria. The system consists of a small pump that puts an oxidizing agent into the water before the pressure tank. The water will need about 20 minutes for oxidation to take place so treating before a holding tank or pressure tank is a must. After the solid particles have formed the water is filtered. The best oxidizing agents are chlorine or hydrogen peroxide. If chlorine is used, an activated carbon filter is often used to finish the water and remove the chlorine taste. The holding tank or pressure tank will have to be cleaned regularly to remove any settled particles.

The pH of water is a measure of the acidity or alkalinity. The pH is a logarithmic scale from 0 – 14 with 1 being very acidic and 14 very alkaline. Drinking water should be between 6.5 and 7.5. For reference and to put this into perspective, coffee has a pH of around 5 and salt water has a pH of around 9. Corrosive water, sometimes also called aggressive water is typically water with a low pH. (Alkaline water can also be corrosive.) Low pH water can corrode metal plumbing fixtures causing lead and copper to leach into the water and causing pitting and leaks in the plumbing system. The presence of lead or copper in water is most commonly leaching from the plumbing system rather than the groundwater. Acidic water is easily treated using an acid neutralizing filter. Typically these neutralizing filters use a granular marble, calcium carbonate or lime. If the water is very acidic a mixing tank using soda ash, sodium carbonate or sodium hydroxide can be used. The acid neutralizing filters will increase the hardness of the water because of the addition of calcium carbonate. The sodium based systems will increase the salt content in the water. 6.1% of the wells tested were found to have acidic water this year.

Water that contains high levels of dissolved minerals is commonly referred to as hard. Groundwater very slowly wears away at the rocks and minerals picking up small amounts of calcium and magnesium ions. Water containing approximately 125 mg/L can begin to have a noticeable impact and is considered hard. Concentrations above 180 mg/L are considered very hard. As the mineral level climbs, bath soap combines with the minerals and forms a pasty scum that accumulates on bathtubs and sinks. You either must use more soap and detergent in washing or use specially formulated hard water soap solutions. Hard water can be just a minor annoyance with spotting and the buildup of lime scale, but once water reaches the very hard level 180 mg/L or 10.5 grains per gallon, it can become problematic. One well tested at 571.7 mg/L, but overall 18.4% of homes tested had hard water. Given the number of homes with elevated sodium and our local geology, it is probably a reflection of the number of homes with water softeners.

Water softening systems are used to address the problem are basically an ion exchange system. The water softening system consists of a mineral tank and a brine tank. The water supply pipe is connected to the mineral tank so that water coming into the house must pass through the tank before it can be used. The mineral tank holds small beads of resin that have a negative electrical charge. The calcium and magnesium ions are positively charged and are attracted to the negatively charged beads. This attraction makes the minerals stick to the beads as the hard water passes through the mineral tank. Sodium is often used to charge the resin beads. Water softeners can be used to remove small amounts of other metals like iron and some forms of arsenic. As the water is softened, the sodium ions are replaced and small quantities of sodium are released into the softened water, thus the salty taste of softened water. When the water softening system is recharged the excess sodium solution carrying the calcium and magnesium is flushed to the septic system which may shorten the life of the drain field.

At the present time the EPA guidance level for sodium in drinking water is 20 mg/L. This level was developed for those restricted to a total sodium intake of 500 mg/day and does not necessarily represent a necessary level for the rest of the population. Based on taste of the water levels of sodium should be below 30 to 60 mg/L based on individual taste. Water softeners are often sold to solve every water quality problem because they have some ability to remove other contaminants and are quite profitable. The resin bed used will determine specific contaminant removal. Softened water can have a low pH and high levels of chloride, corrosion control problems and softening systems can encourage the growth of reducing bacteria. Water softening systems add sodium. Reverse osmosis systems and distillation systems remove sodium and are safe for household use, but addressing hard water by using vinegar to descale pots and dishwashers, regularly draining hot water heaters, and using detergents formulated for hard water might be a better solution for you if your water like mine is only modestly hard.



No wells were found that had arsenic exceeding the EPA MCL for drinking water of 10 ppm. While arsenic is a naturally occurring element found in soil and groundwater it is not typically found at significantly elevated levels in this geology. Arsenic can also be an indication of industrial or pesticide contamination. Arsenic can be very tricky to remove depending on its form and the other contaminants present. Possible solutions for elevated levels of naturally occurring arsenic are reverse osmosis system or iron oxide filter system.

You Can Fix a Well with E Coli

If you find E colie or fecal coliform in your well the first step you should take is to protect your health then try and identify the source of the E coli and eliminate it.

1. If the sample tests positive for E coli then the first thing to do is chlorine shock not only the well, but also the inside piping and any treatment equipment to disinfect your home. 
2. Retest the water after the chlorine has left the system in about 10 days to two weeks see if E coli is present. 
3. If your well water tests positive again for total E coli, then the water must be treated to make it safe for consumption, while the source of is identified and eliminated if possible. 

Possible sources of E. coli contamination are septic tanks leaks, septic leach field or system failure, animal manure storage systems or in some areas with installed sewer systems and wells, sewer pipe leaks. There are instances when a neighborhood is hooked up to sewers, some of the homes do not pump out the old septic tanks and years later are found leaking.

Shallow groundwater is most easily contaminated by septic leaks, septic system failures, animal waste and sewer leaks. Nonetheless, in certain geology shallow sources of contamination can find their way into deeper groundwater. In fractured rock systems with limited overburden like we have here in the western portion of Prince William county, a fracture can carry contamination to deeper groundwater and spread the contamination.

Very shallow groundwater wells- dug or bored wells often become contaminated when the shallow aquifer becomes contaminated. These types of are prone to go dry during droughts and because they are shallow (less than 40 feet deep) are more subject to pollution. Drilled wells have more protection since they are more than 40 feet deep, typically more than 100 feet deep.

Well construction defects such as insufficient well casing depth, improper sealing of the space between the well casing and the borehole, corroded or cracked well casings, and poor well seals or caps can allow sewage, surface water, or insects to carry coliform bacteria into the well.

To prevent contamination to a well, regulations in Virginia and several other states have specified well construction standards since 1992. To provide the best natural protection these regulation require that the well should be 100 feet from the nearest edge of the septic drainfield and 50 feet from the nearest corner of the house. If the land area is small, the way to accomplish this is to separate the two as far as possible, with the septic drainfield downgradient of the well and go deep with the well. Obtaining the needed separation with vertical distance.

In Virginia (and most places) if a well is more than 100 feet deep the septic leach field need be only 50 feet away, but there are many wells like mine that have more than one water level and the shallower one is less than 100 feet deep (in my case 46 feet) making the well much more susceptible to contamination for the septic effluent leaching into the ground. You must make sure that the well is lined, grouted and the geology protects you from the drainfield to protect the well from the shallow ground water and being impacted by the septic system.

Septic drainfields also have a limited life. The life of a septic drainfield is dependent on how the system is managed, the frequency of septic tank pump outs, and the number of people living in a house, but 25-30 years is the typical life of those systems. After decades of use a septic drainfield can become a long term source of fecal or E coli contamination

Fecal coliform is the group of the total coliform that is considered to be present specifically in the gut and feces of warm-blooded animals. E. coli is considered to be the species of coliform bacteria that is the best indicator of fecal pollution and the possible presence of pathogens.

Back in the day we always recommended that a well that was contaminated with E coli be replaced with a new well. That is not always possible or desirable. I have observed several instances where E coli was eliminated from a well after repair of a failing septic system, but that takes time; so in the meantime the water must be treated to make it safe for consumption. Replacing a well can cost between $10,000 and $20,000, and cannot always be done.

Continuous disinfection of the water is necessary to protect you from fecal bacteria and E. coli. This is easily accomplished by installing either a UV (ultra violet) light or chlorine disinfection system. Your choice of systems should be based on personal preference and what other contaminants are present in your water. Both UV light and continuous chlorination do a good job of killing coliform bacteria including fecal coliform and E coli. However, chlorine treatment will control nuisance organisms such as iron, manganese, iron and manganese reducing bacteria and sulfate-reducing bacteria. Chlorine in water at the concentrations used for treatment is not poisonous to humans or animals. However, chlorine can impact the smell and/or taste of water even in very low concentrations. Household chlorination systems often use higher chlorine concentration than the typical 0.3 - 0.5 ppm (parts per million) concentration used for chlorination of public water supplies because the contact time is much shorter in home systems. UV light systems require filtration before the UV light maximize the functioning of the UV light system.

Both UV light and chlorine disinfection require additional treatment. Neither method of disinfection kills Giardia or Cryptosporidium, two microscopic parasites that can be found in surface water and groundwater that has been impacted by sewage. Both parasites produce cysts that cause illness and sometimes death. Giardia are often found in human, and dog feces. Cattle feces appear to be the primary source of Cryptosporidium, although these parasites have also been found in humans and other animals. Membrane filtration is the usual treatment for these parasites- a one micron or smaller membrane is required for this. There are new filter systems that combine carbon and one micron or smaller membrane a a special filter designed for this purpose.

Many manufacturers make whole house filters, typically they make a casings in 10, 20 or 30 inch and make different cartridges to address the various problems. To ensure that a filter removes Cryptosporidium, you can look for "NSF 53" or "NSF 58" and the words "cyst reduction" or "cyst removal." Reverse osmosis can also accomplish parasite removal, but typically only treats one sink rather than a whole house, wastes a lot of water, and if your water is at all hard requires a water softening system.

Emergency Disinfection of Your Well after the Flooding

Severe flooding can cause septic waste and even chemicals from cars and factories can enter groundwater making it 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 with the flow of the groundwater). A well may not be a safe source of water after the flood, but in all likelihood it will recover. Often all you need to do is flush the well then disinfect it.

Be aware that waste water from malfunctioning septic tanks or chemicals seeping into the ground can contaminate the groundwater for several weeks if there was significant flooding.  The first thing you need to do is respond to any immediate problems and then test the water periodically to verify the continued safety of drinking water.

Unless your well was submerged near a trucking depot, gas station or other industrial or commercial source of chemicals it is likely that torrential rains or flood waters have infiltrated your well and you have “dirty or brownish” water from surface infiltration. This is especially true if you do not have a sanitary cap on your well or 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. It is most likely if your yard was flooded or your well submerged that you have some surface infiltration of water. In that case, chlorine shocking your well should disinfect your well and last at least 7-10 days.

If your water is brown, the first thing you should do is 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 it is time to disinfect your well. This is an emergency procedure that will kill any bacteria for 7 to 10 days.

After 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.

To disinfect a well you will need common unscented household bleach.  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. You will also need rubber gloves, old clothes and protective glasses to protect you from the inevitable splashes, and don't forget a bucket to mix  bleach with water to wash the well cap.

•        Put on the old clothes and safety glasses
•        Run your hoses from the house to the well
•        Fill bucket with half water and half chlorine. 
•        Turn off power to the well
•        Drain the hot water tank
•        Remove well cap
•        Clean well cap with chlorine and water solution and place in clean plastic bag
•        Clean well casing top and well cap base using brush dipped in chlorine water
•        Pull wires in the well aside if they are blocking the top of the well and clean them with a rag dipped in chlorine water mixture. Make sure there are no nicks or cuts in the wires. 
•        Put the funnel in the well top and pour in the chlorine and water mixture
•        Now pour in the rest of the chlorine SLOWLY to minimize splashing
•       Go back to the basement and turn the power to the well back on
•        Turn on the hose and put it in the well 
•        Sit down and wait for about 45 minutes or an hour
•        After 45 minutes test the well to make sure that the chlorine is well mixed
•        Use the hose to wash down the inside of the well casing
•        Turn off the hose
•        Carefully bolt the well cap back in place
•        Now go back into the house
•        Fill your hot water heater with water
•        Draw water to every faucet in the house until it tests positive for chlorine then flush all your toilets. Turn off your ice maker. 
•        Then do not use the water for 12-24 hours 
•        Set up your hoses to run to a gravel area or non-sensitive drainage area. The chlorine will damage plants 

After 16 hours turn on the hoses leave them to run for the next 6-12 hours. The time is dependent on the depth of the well and the recharge rate. Deeper wells with a faster recharge rate take longer. If you cannot run your well dry and it recharges faster than the hoses use water you will need to keep diluting the chlorine. If you can run your well dry, you might have to let it recharge and run the water off again to clear the chlorine.

       After about 6 hours of running the hoses begin testing the water coming out of the hose for chlorine. Keep running the hose and testing the chlorine until the chlorine tests below about 1 ppm.

•        Drain the hot water heater again, open the valve to refill it and turn it back on
•        Open each faucet in the house (one at a time) and let run it until the water tested free of chlorine. Be aware the hot water will sputter- big time- until all the air is out of the system. Flush all the toilets
•        Change the refrigerator filter cartridge and dump all your ice and turn your ice maker back on. 

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. 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. Hopefully, a single disinfection will be enough. 

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 help in Virginia  or my contact information through this link by entering Prince William County or my name in the search box. I am happy to answer emails.

Types of Water Wells- Bored Wells

From Royal Pump and Well VA

There are two main types of modern wells, they can  often be distinguished by the diameter of the bore hole. The two types are bored wells and drilled wells. There has been a shift towards well regulations and drilled wells in the past couple of decades, but in areas of the Appalachian Plateau and other locations where clean low yielding groundwater sources are found relatively close to the surface- usually under 100 feet below grade.

Bored wells get their name from the way they are constructed. Bored wells are constructed using a rotary bucket auger. They are usually completed by installing a perforated casing (also called cribbing) or using a sand screen with continuous slot. One advantage of bored wells is the large diameter of the casing, from 18-36 inched. It provides a water storage reservoir for use during peak demand periods. A disadvantage of utilizing a shallow groundwater aquifer is that it generally relies on annual precipitation for recharge. So these systems are often installed with an additional cistern to ride out water shortages may occur following long dry periods in summer and extended freeze up during winter months. It can also be more susceptible to contamination from surface land-use activities.

As opposed to the 6 inch diameter drilled wells, bored wells are generally used where the groundwater aquifers are both shallow and low-yielding. Typically, I see bored wells with between 0.5-1.0 gallon per minute yield. Though, I have heard of bored wells in Goochland with up to 5 gallons a minute. A well that yields only 0.5 gallon per minute will provide 720 gallons per day which is more than enough for a household. Bored wells range in depth from 30 feet to 100 feet. To compensate for the low-yield of the aquifer, large diameter bored wells serve as storage reservoirs to provide water during periods of high demand. A bored well with a diameter of 3 feet provides 53 gallons of water storage per foot of depth.

Because they are shallow, bored wells are susceptible to both contamination and drought. This is why they are falling out of favor. A large protected land area and proper location of the well reduces the possibility of contamination. A well should be higher than the surrounding ground surface for good drainage. All possible sources of contamination should be at a lower elevation than the well, and the distances to those contamination sources must comply with local Water Well Construction Codes but should be 100 feet from septic tanks and leach fields to be safe. Tests performed in the past have shown that bacterial contamination is usually eliminated after water has filtered through 10 feet of normal soil. Therefore, the well must be constructed to ensure that at least the top 10 feet of casing is watertight.

There is more than one approach to boring a well and several design variations. Bored wells can be completed with either jet or submersible pumps. They can also be completed with a technique called buried slab. With this method, there is a smaller upper well casing that is 4-8 inches in diameter and may or may not be exposed. This smaller well casing extends 10 feet or more feet below the ground surface and is embedded in a hole that is formed when the reinforced concrete buried slab is manufactured, or connected to a pipe cast in the concrete slab. This type of well can be confused with a drilled well. In other designs the concrete casing that ranges in diameter from 18 inches to 3 feet extends to the surface and the lining is sealed with grouting to at least 10 feet below grade and the pitless adapter is below that as seen above.