This is the water analysis for a recently drilled well for a new home. The test results are summarized in the chart below. Though over 100 substances were tested for, only substances for which there was a finding are listed.
In summary the analysis found levels of: iron at more than 3 times the EPA Safe Drinking Water Act secondary standards and manganese at almost 30 times the EPA Safe Drinking Water Act secondary standards, turbidity was 13 times the standard and the water tested as very hard. In addition, the home purchaser reported that the “water smells like sulphur in the house and very annoying.” I assumed that the purchaser had a hydrogen sulfide problem, there is adequate sulfate present, but the water was not tested for hydrogen sulfide.
As you can see, turbidity the measure of the degree to which the water loses its transparency due to the presence of suspended particulates is a problem. The more total suspended solids in the water, the murkier it seems and the higher the turbidity. Turbidity can be caused by silica, soil finds or iron bacteria. Generally, iron bacteria and other reducing bacteria are not problems in the first couple of years of a well. It takes time for the bacteria introduced during drilling to spread. Iron bacteria are present in most soils and can be introduced into a well or water system during drilling, repair, or service. Though, iron bacteria can produce unpleasant tastes and odors commonly reported as: "swampy," "oily or petroleum," "cucumber," "sewage," "rotten vegetation," or "musty,” it is unlikely that is the problems here. The most common causes of turbidity in wells are dirt and colloidal solids that are too small and too fine to settle out properly.
My recommendation would be to begin by addressing the iron, manganese and assumed hydrogen sulfide problem. A greensand filter often referred to as oxidizing, iron or red water filter can be a good solution. Like most home model water filters the typical manganese greensand filter is a pressure filter, a fully enclosed tank type filters that operates at the same pressure as the water delivery system so that you do not need to buy a booster pump. These devices are used for a variety of water treatment processes such as taste and odor improvement, iron and manganese removal and removal of suspended matter (turbidity) in water. The water treatment performed by a pressure filter is determined by the filter media that is inside the tank. Most companies that sell pressure filters use the same tank for all treatments but change the inside filter media depending on the type of treatment needed.
Iron filters contain a resin designed to remove iron and manganese that is in solution. It will also act as a filter and catch iron and manganese precipitates that have been oxidized before reaching the filter. Typically these filters are effective for iron and manganese removal concentrations up to 10 ppm. However, this type of filter will not tolerate iron bacteria, because the slimy material that is produced coats the greensand and fouls it, and over time iron bacteria builds up in a well. That is why the usual first step is to treat the well for iron bacteria. In addition the greensand filter must be regenerated with a new solution of potassium permanganate when the oxygen is depleted. This process is similar to regenerating a softener. The filter must be backwashed every so often based on the size of the filter. The typical cycle is weekly and there are systems that are automatic.
The iron filters have been less successful in actual practice. First, the well must be regularly treated to knock back iron bacteria. In addition, for the iron filter to work properly the correct flow rate is the secret to effective iron removal. Adequate flow is required to clear the filter bed of sediment before it becomes too dirty. Most well pumps used for private drinking water wells supply 10 to 15 gallons per minute (gpm) of flow. The size filter that can be used is limited by the backwash water available. That is why many of the home pressure filters are tall thin “bottle-type” units that are only 8 inches in diameter. This size filter can be backwashed with 8 to 10 gpm flow. However, the low surface area only provides treatment for a limited water flow of about 2 gpm on average or about 5 gpm for short peak flows. Use of higher volumes of water would result in iron breakthrough, but some of the breakthrough can be picked up by the needed water softening system that has some ability to control iron and manganese.
Another approach for iron, manganese and hydrogen sulfide removal is chlorination. Chlorination and filtration can remove high concentrations of iron, iron bacteria, and hydrogen sulfide gas. The iron, manganese and hydrogen sulfide gas is oxidized by the chlorine in a holding tank. A sediment filter is used to remove the iron and manganese particles followed by an activated carbon filter used to remove excess chlorine and other impurities. The resulting water has an excellent taste. For this system to work the pH of the water must be above 7 so a small amount of neutralizing solution of soda ash (sodium carbonate) or caustic soda (sodium hydroxide) into the holding tank. This raises the sodium content of the water. Potassium can be substituted for sodium at a higher price and may be preferable. Adjust the feeder to provide the correct rate to result in a pH of near 7 that is necessary for chlorination. No other method of home water treatment has as many benefits as chlorination- disinfection and oxidizing agent. Both approaches can be effective, but the pH adjustment using a neutralizing filter will make what is already very hard water harder. And the soda ash or caustic soda can raise the sodium levels which is already elevated and will probably be raised more by a softener.
With the hardness at 270 mg/L a water softener seems necessary. Bath soap combines with the minerals and forms a pasty scum that accumulates on bathtubs and sinks. The minerals also combine with soap in the laundry, and the residue doesn’t rinse well from fabric, leaving clothes dull. Hard water spots appear on everything that is washed in and around the home from dishes and silverware to the floor tiles. Many can live with the water spots and soap scum issues by adding vinegar to dishwashers and using hard water formulated shampoos, but are induced to treat their water because of the potential impacts on plumbing and appliances.
When heated, calcium carbonate and magnesium carbonate are removed from the water and form a scale (lime scale) in cookware, metal hot water pipes, dishwashers and water heaters. As the scale builds up more energy is required to heat the water and hot water heater and small kitchen appliances have to work harder which will burn them out eventually. Thus, in hard water locations hot water heaters and other appliances have a shorter life. However, softened water increases the potential for leaching heavy metal from metal pipes. Not a problem in the new construction.
Eventually the surfaces of the beads in the mineral tank become coated with the calcium and magnesium. To clean the beads, a strong salt solution held in the brine tank is flushed through the mineral tank this occurs two or three times a week and consumes 20-30 gallons of water. Sodium is typically used in the brine tank, but potassium can also be used. The excess sodium solution carrying the calcium and magnesium is typically flushed to the septic system. The amount of sodium in water conditioning systems can be a real problem for humans, the septic system and the environment. There are areas that are banning their use. Softened water is not recommended for watering plants, lawns, and gardens due to its sodium and chlorine content; however, plants are fine with potassium.
Also, you do not want to drink or cook with what is usually high sodium softened water. It might be worthwhile to see if you can do without the water softener, or use potassium chloride instead of the sodium chloride to reduce the sodium. The sodium levels in the water are already elevated, using the potassium versions could reduce this impact. There are no health-based drinking water standards for sodium and potassium. Neither has a secondary drinking standard, but potassium is less harmful to the garden and septic system. Traditionally softened water using sodium chloride can cause toilet paper clogs in septic piping and impair the functioning of the septic tank.
A water softener is necessary if the homeowner wants a reverse osmosis systems to eliminate lead, MEK or tetrahydrofuran. Waste water from reverse osmosis systems is typically connected to the house drains and will add to the load on the household septic system. This is a significant additional water use and load to the septic system and could impact the life and functioning of the septic system and well since a 5 gallon a day reverse osmosis system might waste 50-90 gallons a day. The principal uses of reverse osmosis in are for the reduction of high levels of nitrate, lead, mercury, arsenic, cadmium, sulfate, sodium and total dissolved solids. Using a soda ash feed on a chemical feed tank will also remove lead an activated carbon filter could also strip out the MEK and tetrahydrofuran (also known as 1,4 dioxane) is an emerging contaminant in drinking water. The technologies that are proven to remove the largest spectrum of contaminants are Granular Activated Carbon and reverse osmosis. In the waste water industry advanced oxidation processes used to remove 1,4 dioxane from waste water.
Overall, the treatment equipment will cost about $15,000-$20,000 installed and require a service contract to keep the system “tuned.” Good thing the homeowner can afford it.
