Bacteria and Drinking Water

Microorganisms, specifically coliform bacteria, are naturally occurring and usually harmless. Bacteria are the most common contaminant found in well water. Bacteria can be introduced into your water supply in a variety of ways. One common entry point in through your well cap or from any work that is performed on your well or household plumbing. Once these organisms have had a chance to take hold you may find it necessary to perform more than one chlorination in order to thoroughly disinfect the whole supply. The presence of coliform is an “indication” that more harmful organisms may be found in the source water or in the distribution (plumbing) system. In most cases, a bacterial contamination problem can be remedied by disinfecting the water supply with chlorine. The USEPA recommends every well-owner have their well tested annually for both bacteria and nitrates.

Nitrate Monitoring

Next to bacteria, nitrates are the most common contaminant found in well water. At high Concentrations it is an indication that animal/human wastes or agricultural applications may be entering the water supply. Low levels, 0-11 mg/L, can usually be explained as a “naturally occurring” part of the nitrogen cycle where microorganisms breakdown organic material, yielding nitrogen as a by-product. Nitrates are a special concern to young children and women of child bearing age. Excessive levels of nitrates have been linked to the occurrence of “Blue Baby” syndrome. The USEPA recommends every well-owner have their well tested annually for both bacteria and nitrates.

Do I have enough Fluoride in my water?

Obviously fluoride is essential for good dental hygiene. Naturally occurring fluoride in well water varies. The concern is that your water may lack a sufficient amount of fluoride for good dental hygiene. Interpretation of fluoride results is best left up to your dentist or pediatrician. Concentrations above 4 mg/L can lead to endemic dental fluorosis, which causes brown molting or spotting of teeth.
Chlorides and Drinking Water
(See Salt Water Intrusion)

Staining of fixtures

The characteristic reddish-brown stains found on laundry and on plumbing fixtures is caused by iron. It is one of the most common elements found in the soil and as a result it is a very common contaminate in our local well water. High levels may give the water a metallic taste. Your water can be clear and still contain iron. Often after the water sits and is exposed to the air the iron will drop out of solution and settle in a toilet bowl or other fixture.

Water hardness is a result of calcium and magnesium concentrations in the water. As rain water containing carbon dioxide flows through the earth, it dissolves these minerals adding them to your water supply. These minerals will be deposited on your hot water heating element, making it much less efficient. You will also see deposits on shower fixtures and glassware. Hardness can also cause soap not to lather. Silica is a common element of sand and wells in most of the surrounding counties.

How does lead get into my drinking water?

Lead has been a widely publicized issue. As of December 1992, all “public” water supplies will have to be monitored for lead. Private well owners should be concerned about lead if: (l) the plumbing system in your home is primarily copper and was built prior to 1986, and (2) if your water is corrosive (see pH). It would be unlikely to find naturally occurring lead levels in a private well. Lead is introduced in your water supply as the water passes through lead-soldered joints and faucets containing lead. The sample should be drawn from the kitchen tap after the water has remained in the line for at least six hours but not more than 18 hours. Do not allow any water to run to waste when collecting a lead sample.

What is the pH reading telling me?

This is a general measure of the acid or alkaline strength of a water supply. In this area most supplies tend to be more acidic and thus have a low pH reading. This test should be conducted on site. Blue-green stains on your plumbing fixtures are an indication that you water is corrosive and may be stripping the copper and lead from the interior plumbing and depositing it on your fixtures and in your water.

Should I be concerned about Salt Water Intrusion?

This occurs when there is a movement of saline water into a freshwater aquifer. Maryland Department of the Environment Ground Water Report 2012 stated that “Aquifers in several coastal areas of Maryland have experienced salt water intrusion as a result of over pumping of the aquifers. This is a test that is strongly recommended for anyone looking to purchase a home. The test consists of measuring the chloride concentration and the amount of Total Dissolved Solids in the water supply. High levels of chlorides characteristically produce a foul taste and certain corrosive effects. However, Chlorides are present in all water supplies at low concentrations.

What is Hydrogen Sulfide?

Hydrogen sulfide is a colorless gas that can exist naturally in groundwater. Sulfur-reducing bacteria present in groundwater use sulfur as an energy source to chemically change sulfates to hydrogen sulfide. They can occur in deep or shallow wells, and reside in plumbing systems. Water that is giving off a distinctive smell is most likely contaminated with hydrogen sulfide. Hydrogen sulfide does not usually pose immediate health problems at the levels it is found in domestic drinking supplies. However, it is certainly an inconvenience Generally speaking, if you are able to smell the odor, then Hydrogen Sulfide is present in your water supply and measuring the amount is not necessary. The gas is produced when micro-organisms react with sulfates, producing hydrogen sulfide as a by-product. The reaction takes a long time to occur, therefore you may only notice an odor, for example upon returning home from a vacation or in a bathroom that is not used regularly.

Your next step is to determine if the problem is in the hot water supply, cold water or both. The magnesium rod used in water heaters for corrosion control can chemically reduce sulfates to hydrogen sulfide. If you run a hot water tap and smell the odor you can get a plumber to remove/replace the anode rod in the hot water heater and this may solve the problem. To check the cold side it is helpful to turn the cold on in a shower and close the door/curtain and allow the water to run for a few minutes for the odor to build up. If you can smell it in the cold water side you will need to contact a water treatment company for a long term solution. For a temporary solution you can chlorinate the well and the odor will go away temporarily, the amount of time will be different for every well.