Thursday, November 11, 2010

Drinking Water Problems with Your Private Well Part 2

Contamination from human and animal waste and chemicals can be real health hazards and should be addressed immediately. However, most of the water quality issues with private wells are from naturally occurring contamination. These are contaminants that are produced from the underlying soil and rock geology and wildlife. From the underlying rocks radionuclides and heavy metals can enter the groundwater. There are areas with natural occurring arsenic, cadmium, chromium, lead, selenium and fluoride. While some of the symptoms of mineral contamination are obvious, never buy a treatment system until you have tested your water and identified the correct solution. Other contaminants may be present that need to be addressed. While many natural contaminants such as iron, sulfate, and manganese are not considered serious health hazards, they can give drinking water an unpleasant taste, odor, or color.

The WaterCheck with Pesticides is an informational test packages targeted to be an affordable option for consumers. The WaterCheck with Pesticide covers 15 heavy metals, 5 inorganic chemicals, 5 physical factors, 4 trihalo methanes, 43 volatile organic chemicals (solvents), and 20 pesticides, herbicides and PCB’s. The Minimum Detection Levels, which are the lowest levels at which the laboratory detects that contaminant are below the levels established by the Safe Drinking Water Act so this affordable (relatively) test will serve as a broad screen of drinking water.

A lot of the well water in Virginia is hard water (though there are areas where soft water occurs naturally.) Hard water contains minerals, such as calcium, magnesium, and iron. Water containing approximately 125 milligrams of calcium, magnesium and iron per liter of water can reduce the cleaning action of soaps and detergents and can form a scale (lime scale) in cookware, hot water pipes, and water heaters. There are a number of simple things you can do to reduce the effects of hard water in your home, without having to resort to treating your water, so called softening. My water has elevated levels of calcium and magnesium. My iron content is very low. High iron content can begin to stain your teeth at 0.3 parts per million (ppm), you may also notice brown/orange stains on tubs, inside dishwashers, sinks and laundry. There are simple things to do to address hard water, but with excessive iron you might consider additional treatments.

Choose a detergent based laundry product. Some laundry detergents/soaps do not produce as many suds in hard water, these are likely to be soap-based products and do not work as well in hard-water as detergent based products. These days, there are laundering powders and liquids available for a wide range of water hardness. Also, manufacturers often recommend using slightly more detergent to compensate for the hard water. Check the package.

Reduce the temperature of your hot water heater. When water temperature increases, more mineral deposits will appear in your dishwasher, hot water tank and pipes. By reducing the temperature, you will save money and will reduce the amount of mineral build-up in your pipes and tank. Use rinse agents to remove mineral deposits. There are low pH (acidic) products available to remove mineral deposits from pots and pans and dishwasher. Alternatively, you can use plain white vinegar by using the dishwasher dispenser or placing a cup of vinegar on the dishwasher rack. Boil some white vinegar in your kettle to remove hard water deposits. Drain and rinse your hot water heater annually.

In days past, at the first sign of hard water, domestic water supplies were commonly softened by using a tank containing an ion-exchange material, which takes up the calcium, magnesium and small amounts of dissolved iron from water in exchange for sodium. Conditioning the home water supply with sodium is pleasing to some. The amount of sodium in water conditioning systems is a real problem and may increase the corrosively of the water. Personally, I do not care to add all that sodium to my diet while removing calcium carbonate and magnesium (something that is also sold in pill form for stronger bones). Household water treatment services are very profitable because of the monthly bills. Conditioning the water supply may include water softening, iron removal, neutralization of acid water, reverse osmosis, turbidity control, removal of objectionable tastes and odors, and aeration. Water softening and filtering are the most common methods of conditioning well water.

Dissolved iron in the water that is oxidized by air to form iron oxide, causes reddish-brown stains in sinks, toilets, tubs, dishwashers, and dishes. Other symptoms of excessive iron are reddish-brown stains or yellowing of laundry, especially after using chlorine bleach. The iron can cause the water to taste metallic. Brown sediment in standing water would be another symptom. With these indications, the water should be tested for iron to verify the problem and determining type and amount of iron problem, select appropriate iron removal equipment such as chlorinator or and sand filter, high capacity water softener or manganese greensand filter. The correct choice of treatment for iron problems can be complex, depending on the level of iron in the water and the presence of other impurities; do not skip a full water test.

Sometimes iron bacteria are mistaken for iron mineral. Iron bacteria forms a reddish slime on walls of toilet flush tank and reduced water flow. Slimy material suspended in clear water. Iron bacteria, which live on iron in the water and have hardened into scale, can be mistaken by a water treatment sales person for iron. The solution for iron bacteria is to address the bacteria problem. Installing a chlorinator to feed into the well near the pump intake and an activated carbon filter to remove excess chlorine and other objectionable tastes or odors will address iron bacteria. Black stains on sinks, tubs, and laundry are often attributed to iron, but actually that is cause by manganese. Water with high manganese may feel greasy. Manganese (often appears with iron). Iron removal treatments also remove manganese.

Low pH, commonly called acid water; or corrosive water is most common in coal county and areas underlain by Triassic shales or limestone and can often caused by a high concentration of carbon dioxide. Water softeners may increase the corrosiveness of acid water making the situation worse. Low pH water can corrode water pipes. Water dripping from corroded iron or galvanized pipe has a rusty color. Corroded copper or brass pipes cause blue-green stains on plumbing fixtures. Laundry may have red, reddish-brown, or blue-green stains. The water may also have a metallic taste. The acidity level will determine the appropriate treatment such as aeration, soda ash feeder, or neutralizing filter.

Hydrogen sulfide, sulfate reducing bacteria, or sulfur bacteria can cause a rotten egg odor. Copper and silver turn black in the water. Iron, steel, or copper parts of pumps, pipes, and fixtures corroded. Black stains on laundry and porcelain. Black particles in water are indications of this problem. (Note that manganese may also cause black staining on porcelain fixtures.) Compounds such as iron sulfide, calcium sulfide, and sodium sulfide can interfere with hydrogen sulfide removal so multiple treatments may be required test your water to select the appropriate treatment system. Appropriate treatments may include chlorination or aeration followed by filtration through a sand filter.

Objectionable taste or odor other than hydrogen sulfide can be caused by decaying organic matter, pollution from surface drainage, insufficient chlorine being used to disinfect water. Also, there are people who simply do not care for a high mineral content. Install activated carbon filter or automatic chlorinator followed by activated carbon filter. Turbid, cloudy or dirty water, dingy laundry or other similar problem can be caused by silt, sediment, small organisms or organic matter, suspended in the water. These do not need to be addressed unless they are a nuisance. Installing a whole house fiber or a sand filter will address those problem, but will introduce a potential area for creation of other problems if not properly maintained. Coliform bacteria can persist within slime formed by naturally occurring ground water microorganisms. The slime (or biofilm) clings to the well screen, casing, drop pipe, and pump and may even invade filter systems. The pros and cons of each water treatment system should be carefully evaluated before choosing to treat water or selecting a treatment system for you home.

4 comments:

  1. We live in PG County, MD and have well water. I'm wondering what type of filter system to use for drinking water. I've noticed my childrens teeth developing a gray color that is not removed with regular brushing, but does come off after a dental cleaning. Our water does not have any odor/color and a water test showed that everything checks out fine. Any suggestions?

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    1. Judo,
      You need to test your water for more than bacteria. Check your iron levels. Graying on teeth is typically excess iron, but the levels that would stain teeth would really stain plumbing, clothes, etc. and impact the taste of your water. So you might want to check vitamin supplements your children are taking.The good news is the grey will polish off at the dentist.
      Well water should be analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria.
      The standard Secondary Maximum Contaminant Level (SMCL) for iron is 0.3 milligrams per liter (mg/L or ppm) and in this part of the country usually is found with elevated levels of manganese. This level of iron and manganese are easily 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. 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.

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    2. Thank you for the detailed response.

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    3. I live close to you have noticed the same thing, Judo. If you have found the solution, please let me know. Thank you, Elizabeth, for the helpful response.

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