The Causes of Brownish or Dirty Well Water

The Virginia Master Well Owner Network (VAMWON) is an organization of trained volunteers dedicated to promoting the proper construction, maintenance, and management of private water systems (wells, springs, and cisterns) in Virginia. The Cooperative Extension Services in Virginia manages the program and have numerous publications and fact sheets that can help homeowners make educated decisions about their drinking water. The volunteers can help homeowners interpret their test results and make educated decisions about what treatment might be appropriate and desirable or appropriate solutions to problems..

VAMWON Notes from the Field are a series of stories of the questions and sometimes the solutions I’ve encountered as a VAMWON volunteer. The VAMWON volunteer or Agent can help you identify problems with the water system and provide information on suggested treatments options and other solutions. You can find your VAMWON volunteer neighbor through this link by entering your county in the search box.

I received the following in an e-mail “A week ago Monday we had slightly brown water. I called the landlord who came by to say he was having a plumber look at the well situation. He stated with all the rain we have been having it has had an effect on the well. Yesterday morning I noticed brown water again. I called the landlord who had the plumber call who parroted that all the rain had caused cloudy water.”

Before you call a plumber, well driller, or water treatment company you should test your water so that the problem can be properly diagnosed. It is cheaper to test your water than call a plumber and you need to understand what the real problem is to correct it. First, 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. 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). However, it is to be noted that when a water supply has been shut off for a period of time any rust in the systems is likely to be dislodged when the water supply is turned back on. This is true for wells and public supply water systems.

After rust in the household fixtures there are three likely causes for well water to be brown or brownish, surface infiltration, well collapsing or water level dropping or iron (and/or manganese) in the water. Earthquakes can also cause a change in water, either by loosening fine grains of silt and soil or lowering the water level. According the 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. A complete water test to determine the source and extent of your problem and possible treatments or solutions should include tests for manganese concentration, iron concentration, iron bacteria, pH, hardness, dissolved solids as well as the tests for total coliform, fecal coliform and e-coli bacteria.

Surface infiltration of water is due to impaired pump and casing system. In this instance this would seem to be what the landlord was insinuating with the comment about all the rain. A properly functioning well with a sanitary well cap should not be impacted by rain. The pump system consists of the well cap, well, and grouting. Surface flooding, excessive rain or snow melt could flow down the casing area if the grouting is damaged or the well cap not sealed properly. This of course would also allow bacteria from the surface to enter the well. Testing the well for bacteria would determine if the water were safe to drink and would indicate if there was surface infiltration.

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 second likely source of brown water 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. 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.

The third likely 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. An appropriate response to the presence of iron is to install the right treatment system.

The type of iron present is important when considering water treatment. Water that comes out of the faucet clear, but turns red or brown after standing is “ferrous” iron, commonly referred to as “clear-water” iron. Water which is rust colored, red or yellow when first drawn is “ferric” iron, often referred to as “red- water” iron. Iron can form compounds with naturally occurring acids, and exist as “organic” iron. Organic iron is usually yellow or brown, but may be colorless. A combination of acid and iron, or organic iron, can be found in shallow wells and surface water. Although this kind of iron can be colorless, it is usually yellow or brown.

Finally, when iron exists along with certain kinds of bacteria you may get bacterial iron that leaves a reddish brown or yellow slime that can clog plumbing and cause an offensive odor. You may notice this slime or sludge in your toilet tank when you remove the lid. Before you attempt to solve any water problem that appears to be iron-related, it is important to have your water tested. A complete water test to determine the extent of your iron problem and possible treatment solutions should include tests for iron concentration, iron bacteria, pH, dissolved solids, hardness as well as the tests for total coliform, fecal coliform and e-coli bacteria. The test results properly interpreted will allow you to address the underlying problem and spend your money to correct the right problem.