| Corrosive well water not only ruins copper pipe, | | | | with the water for pH adjustment to occur and |
| plumbing and fixtures, it can also cause heavy | | | | the soda ash solution to thoroughly mix in the |
| metals such as lead, cadmium and copper to | | | | water by using a contact tank. However, for |
| contaminate drinking water as the household pipes | | | | many residential applications, the existing pressure |
| corrode. | | | | tank and piping system is enough to provide |
| Well water chemistry varies widely between wells | | | | some mixing, since the pH is neutralized almost |
| and if corrosion is suspected, a simple water test | | | | instantly. |
| can pinpoint what is making the water corrosive. | | | | Soda ash is bought dry, usually in 25 or 50 lb bags |
| Acidity in water is expressed by the pH scale, | | | | and mixed with soft or pure water in the solution |
| which ranges from 1 to 14. A pH of 7 is | | | | tank. When a saturated solution is achieved |
| considered neutral, with less than 7.0 being acidic | | | | (approximately 3 pounds per 5 gallons of water, |
| and greater than 7.0 being alkaline. In addition to | | | | which creates a 10% solution), a solution of |
| pH, alkalinity, calcium carbonate, total dissolved | | | | between 50 and 500 ppm are injected, depending |
| solids and temperature are measured and can | | | | on the pH, alkalinity and flow rate of the water. |
| quickly show if acidity is the main cause of the | | | | In some cases, instead of dissolved carbon |
| corrosion. | | | | dioxide causing the low pH or acidity, the acidity is |
| Acidic water is usually caused by dissolved carbon | | | | caused by mineral acids, either natural or from |
| dioxide in rain water, which allows carbonic acid to | | | | mining or other industrial wastes. In this type of |
| form. As the rainwater soaks into the ground it | | | | water, the pH is less than 4.0 then sodium |
| ends up as the source for the acidic well water | | | | hydroxide (lye) may need to be used with the |
| for homeowners. In some cases, mineral acids | | | | same type of pump that is used for soda ash. |
| from mining or naturally occurring mineral acids | | | | Soda ash works best to neutralize the pH when |
| cause the water to be acidic. | | | | the pH is between 4 and 6.8. |
| If the water is acidic, or in the range of 4 to 6.8, | | | | Another approach to neutralizing acidic water is by |
| the water can benefit by having the pH | | | | the use of a calcite neutralizer filter. These filters |
| neutralized to a pH of between 7.0 and 7.5. | | | | will typically raise the pH of the water to 7.0 to |
| Frequently water that is corrosive is also low in | | | | 8.0 and add 30 to 100 ppm of hardness depending |
| calcium hardness and dissolved solids. This type of | | | | on the alkalinity and water hardness. Unlike soda |
| water can be made non-corrosive by the simple | | | | ash feeders, these units do raise the hardness of |
| addition of soda ash. Soda ash, or sodium | | | | water. They can have certain advantages over |
| carbonate, is a non-toxic product that when | | | | soda ash feeders, if there is sediment in the |
| added to water in the correct dose can raise the | | | | water, or small amounts of iron, in that they also |
| pH to 7.0 to 7.5 without making the water harder | | | | double as self-cleaning filters. |
| or affecting the taste or color of the water. | | | | In neutralizer filters, acidic waters slowly dissolve |
| In some cases if there is dissolved iron or | | | | the calcium and magnesium media on contact as |
| manganese in the water, after the pH is raised, | | | | the water flows through the filter, raising the pH |
| the iron and manganese will oxidize and be visible | | | | of the water and increasing the alkalinity. This |
| in the water. If the iron is greater than 0.3 ppm | | | | eliminates the effects of corrosive water |
| and the manganese is greater than 0.05 ppm, a | | | | chemistries and can help to prevent corrosion of |
| backwashing iron filter should be used after the | | | | piping and fixtures. |
| soda ash is injected. | | | | Neutralizer filter tanks are filled with a blend of |
| Soda ash pump systems automatically inject the | | | | calcium and magnesium carbonates made from |
| soda ash solution into the water when the well | | | | naturally occurring minerals, which dissolve into the |
| pump runs. A small pump called a metering pump | | | | water, making it less corrosive. More mineral can |
| is used to inject a small amount of soda ash | | | | quickly and easily be added to the filter tank, |
| (sodium carbonate) into the water automatically. | | | | typically once per year for most residential |
| For home wells the metering pumps are usually | | | | applications. No special tools are required. |
| wired to turn on and start pumping soda ash | | | | Generally soda ash feeders are preferred if the |
| solution when the well pump is energized or | | | | water has a pH of less than 5 or 5.5, whereas |
| running. | | | | calcite neutralizers may work better when the pH |
| For best results, allow a few minutes of contact | | | | is between 5.5 and 6.8. |