Monday, February 22, 2016

Finding the Cause of Dirty Water in Your Well

Brownish or dirty looking water can be caused by many things. Without additional information, it is impossible to determine the cause and find a solution. With a little effort and money you can narrow down the possibilities. The major causes of brownish or dirty water are:
  1. Surface infiltration or other contamination 
  2. Well collapsing or water level dropping 
  3. Iron (and/or manganese) in the water
  4. Rust or breakdown of the metals in in the household piping or fixtures 
Earthquakes can also cause a change in water, either by loosening fine grains of silt and soil or lowering the water level.
A complete water test to determine the source and extent of your problem and possible treatments or solutions should at a minimum be analyzed for: iron, manganese, nitrate, lead, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria. Your observations and this analysis is your tool for honing in on likely causes of the problem and a solution. You should not skip this step. A private well should be tested regularly to identify any problem, confirm that the water remain potable and help you maintain your well.

Surface infiltration of water is due to impaired pump and casing system. A properly designed and functioning well with a sanitary well cap should not be impacted by rain. The well consists of the well cap, well casing and grouting, and the borehole. 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 could 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 and coliform bacteria present could indicate surface infiltration of water. Typically, a well with surface infiltration has an episodic discoloration of the water often associated with rainfall and snow melt. 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.

If however, you have occasional brown or discolored water and E. coli bacteria is present, you are drinking water impacted by a septic system. The closest system to your well is probably yours, but could also be a neighbor’s failing septic system. Stop drinking the water immediately and call the Department of Health for assistance. The only way to restore sanitary water is to repair the septic system or replace the well. Simply disinfecting the water leaves you drinking everything else that may have found its way into the septic system including soaps, cleanser, solvents, grease, etc.

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 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. Your well could be going dry. If your well is going dry, then the first signs of a problem might be brownish water appearing seasonally when there is a lot of water use at the end of a day.

In many geologies groundwater enters a well through fractures in the bedrock and overtime debris, particles, and minerals clog up the fractures and the well production falls. The Prince William Health Department reports that the drop in water recharge rate could be 40-50% or more over 20-30 years. A low yielding well might have a functional life of only 25 years. Over time sediment and mineral scale build up inside the well closing the fractures that allow water to flow into the borehole. Your might want to estimate your well’s recharge.

A well recharge can be estimated by running water from the pump and measuring the top of the water level in the well. (You might have to hire a professional that has a water level monitor tool if you cannot see the top of the water column.) If the water level does not change, then the well recharges faster than the pump rate. If the level is falling then the each foot in a typical 6 inch cased well represents about 1.5 gallons. Turning on the hoses and running a well dry might also be possible if the well recharge has fallen significantly and your well is essentially using the water stored in the column as a reservoir. A more accurate rate to determine the recharge rate is to use a compressor to blow all the water (and deposits at the bottom of the well) out of the well and time how long it takes the well column to recharge.

You have to call a well driller for this. Make sure that the service provider is licensed to service wells in Virginia (not all states require well drillers and well repair companies to be licensed). In Virginia a well driller should have at least a Class B contractor license and the service provider must be Department of Professional and Occupational Regulation, DPOR, certified Well Water Providers. Since 1992 private drinking water well construction has been regulated in Virginia and well drillers have to be licensed. In many other places well drilling and water wells are still not regulated. The well driller can also examine the condition of the casing, wiring, pump and the well components in the house.

The water level in a groundwater well usually fluctuates naturally during the year. Groundwater levels tend to be highest in the early spring in response to winter snowmelt and spring rainfall when the groundwater is recharged. Groundwater levels begin to fall in May and typically continue to decline during summer as plants and trees use the available shallow groundwater to grow and streamflow draws water. Natural groundwater levels usually reach their lowest point in late September or October when fall rains begin to recharge the groundwater again. The natural fluctuations of groundwater levels are most pronounced in shallow wells that are most susceptible to drought. However, deeper wells can be impacted by an extended drought and take longer to recover. Also, groundwater levels can fall regionally over time through overuse of the aquifer. Land use changes that significantly increase impervious cover and stormwater velocity preventing recharge from occurring over a wide area and can make existing wells more susceptible to drought.

Another source of brown water is iron (and/or manganese) in the water. Iron and manganese can give water an unpleasant taste, odor and color and can also cause reddish-brown stains on laundry, tiles, dishes, glassware, and concrete. Manganese causes brownish-black stains on the same items. Iron and manganese exist in many different chemical forms, and are naturally occurring elements commonly found in groundwater in many parts of the country. Interestingly enough, few surface water sources have high levels of these metals. At levels naturally present in groundwater 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 appear as be left as granules or sediment in tubs.

Under guidelines for public water supplies set by the Environmental Protection Agency (EPA), iron and manganese are considered secondary contaminants. Secondary standards apply to substances in water that cause offensive taste, odor, color, corrosion, foaming, or staining but have no direct impact on health. 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 are easily detected by taste, smell or appearance.

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.

Also, 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.

Finally, rust or breakdown of the metals in in the household piping or fixtures can cause water to appear brown or dirty. Corrosive water over time will cause a breakdown in metal components. If you have plastic piping this is not often a problem, but older pipes and well casings are subject to corrosion that can make the water unsafe to drink. With a well this is not usually episodic, but if this is happening to you and you are on public water it could be a sign of breakdown of the connector lines and fluctuations in the pH and corrosiveness of the water. Old pipes held together by biofilms and prayers are very susceptible to small changes in water chemistry. In homes with wells, and metal casings and pipes can be impacted over time by corrosive water. Lead in old solder and plumbing fixtures is the identifier in the analysis that damaged pipes and or plumbing fixtures are causing the problem.

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