Civil engineering & analytical laboratory services

Corrosive Water Panel

Panel Description Test Included  
Corrosive Water Often indicated by blue-green stains (copper_ on fixtures, corrosive water is one of the common problems in the foothills. alkalinity, copper, hardness(calcium & magnesium), lead, pH, specific conductivity  

The required sampling protocol and amount of water required to run the test is listed below.

Water Required: 1 Quart x2
Sampling Protocol: Plumbing Contamination Protocol

pH (Acidity)
The pH of water is a measure of how acidic it is. A pH of 7.0 is neutral. Higher values indicate alkaline water; lower values indicate acidic water. On the average, water with a pH between 6.5 and 8.5 will probably not cause problems. However, the more alkaline the water is, the more likely it will be to have a “lime scale” build-up in the plumbing, especially if the water is hard. The more acidic the water is, the more likely it will be to cause metallic tastes, stains (blue-green from copper; orange-brown from iron), and corrosion of metal components of water systems. Water neutralizing systems are available. If your water is acidic, please refer to the enclosed Acidic Water Information sheet

Recommended Level:
6.5 – 8.5

Specific Conductivity (Salinity)
Specific conductivity gives an indication of how high the mineral content of the water is , which could indicate potential problems requiring further analysis. Highly mineralized water can cause problems with water stills, boilers, radiators, and filters, and can cause a mineral build-up on cooking utensils and spotting of glassware. The health effects of highly mineralized water depend upon the minerals present and their concentrations. Very high levels have a cathartic reaction and do not quench thirst. To make an approximate conversion to Total Dissolved Solids, another commonly used measure of mineral content, multiply the specific conductivity value by 0.62. If your water has a high mineral content, please refer to the Highly Mineralized Water Information sheet.

Hardness (Calcium, Magnesium)
The hardness test primarily measures the Calcium and Magnesium content of water and reflects the degree of difficulty one can expect in using non-detergent soaps. The harder the water, the more soap is required to overcome the effects of the hardness. High hardness at alkaline pH’s can also result in the formation of lime scale in pipes, cookware, and appliances, especially in hot water heaters. A conventional water softener usually remedies the problem. However, persons on restricted sodium diets should be aware that water softeners can significantly increase the sodium content of water.

Listed below are several possible sources of iron problems:

If our iron-colored soil finds its way into the water source, it may give the appearance of iron contamination. A simple sediment filter is often sufficient to remove moderate amounts of sediment. If the discoloration mainly appears following heavy rainfall, it may be indicative of another problem — contamination by surface water. The coliform bacteria analysis can check whether this is the case.

Corrosive Water
Water that has a pH of 6.8 or less can be corrosive to metal components of water systems, especially if the water is also soft. Iron can be corroded from galvanized pipes and any iron-containing appliance or fitting. A good test for this condition is to compare the water at the source with water from within the house. If it is low in iron at the source, but high at the house, and acidic, you might want to consider installing a water neutralizer to alleviate the problem.

Dissolved Iron at the water source
Iron may already be present at the water source, either as a natural component of the source water or due to the action of corrosive water on iron or steel well casings. For this type of iron problem there are several types of iron filtration systems available at water conditioning equipment sales outlets.

Old galvanized iron pipes
Many older homes have galvanized iron plumbing. Over time the galvanized coating corrodes off, exposing the iron underneath. Iron pipes are notorious for corrosion. One symptom of this problem is the appearance of iron-colored particles, especially in screen filters. Such break-offs of iron corrosion can also cause rust-colored spots on laundry. One solution for this type of problem is to replace the iron plumbing with an approved alternative.

Health Effects:
Compared to the amount of iron normally consumed in the diet, the amount ingested in drinking water is very small, and probably represents little danger of adverse health effects. The EPA limit of 300 g/L was adopted because problems with taste and staining do not occur below that level. However, from 3 – 8 people per 1000 have a rare genetic tendency towards Iron Overloading Disease (primary hemochromatosis).

Related Problems:
Surface film
Very high amounts of dissolved iron can cause the development of a surface film on standing water that resembles an oil slick. Iron removal treatment will alleviate this problem.

Iron Bacteria
There are several species of naturally occuring bacteria that may be associated with the presence of dissolved iron in water, or with iron plumbing. These bacteria are not a health hazard, but can be a considerable nuisance. They are able to use iron as their energy source and may develop into a slimy, iron-impregnated coating on plumbing that can clog filters and other plumbing parts, as well accelerate corrosion.

Occasionally pieces of the slime will break off and appear in toilet bowls and bathtubs. Sometimes there are odors associated with the presence of iron bacteria. These odors are often due to sulfate-reducing bacteria which can take up residence in the slime produced by the iron bacteria. During the course of their growth they produce hydrogen sulfide, a gas that smells like rotten eggs.

In some instances the hydrogen sulfide will combine with dissolved metals (iron, manganese, copper) in the water to produce black precipitates which often collect in hot water heaters. Periodic disinfection of the well and water system with household bleach may bring temporary relief from sulfur odors, but only rarely permanently cures iron and sulfate-reducing bacterial problems. Check with a water conditioning professional for their treatment recommendations.

Manganese in amounts greater than 50 to 100 μg/L may cause dingy laundry, blackish stains on plumbing fixtures, and may impart a metallic taste to water. Manganese treatment systems are available.

Recommended Level:
50 μg/L (0.05 mg/L)

A high copper content of domestic water usually manifests itself as a blue-green stain on white plumbing fixtures, particularly bathtubs. Sometimes the stain is just a streak under a leaking faucet. Sometimes it covers an entire bathtub. Copper also gives water a bitter metallic taste or after-taste, especially first thing in the morning. High copper levels in water can also be an indication that your pipes may develop pinhole leaks in the future.

Is copper harmful to your health? Drinking water regulations treat it only as an aesthetic problem because of the stains, tastes, and corrosion. However, a swig of copper-laden water can cause nausea and vomiting. Some people are particularly sensitive to copper. They can experience severe physiological disorders such as intestinal problems, aching joints, headaches, fatigue, and even mental disorders. In our experience, many doctors are not familiar with this condition.

Where does the copper come from? In the northern Sierra and adjacent valley areas, copper from the well itself is virtually non-existent. Typically it enters the water due to the action of the water on copper pipes. The tendency of water to dissolve copper and other metals is a complex interaction of several factors. These include pH (acidity), calcium, alkalinity (carbonate and bicarbonate), dissolved solids (TDS), temperature, water flow, sulfide, dissolved gases, etc. Changing any one of these factors will affect whether the water will dissolve or corrode metal plumbing.

Most copper problems in our area are the result of acidic water (pH lower than 7.0). See the Acidic Water Information Sheet for details. In these cases, installing a calcite (calcium carbonate) or soda ash (sodium carbonate) neutralizer usually does the trick. In rare instances this does not work.

Listed below are some other possible causes you might explore if a calcite neutralizer does not fix the problem:

Low Calcium
The lower the calcium content of water, the more aggressive it tends to be to metal pipes. If you have a water softener (or if your water is naturally low in calcium), the water may be aggressive to pipes even if the pH is in the “correct” range (above 7.0). This type of problem can often be alleviated by using a mixing valve to mix some of the unsoftened water with the softened water.

Even well balanced water will leave streaks under dripping faucets. Fix the leak to resolve this problem.

Electrical Grounding
In many houses, electrical panels are grounded to water pipes. Stray electrical currents can cause corrosion of pipes. This type of problem can be tested using a current meter between the pipes and a solid ground (such as a grounding rod driven into the ground). Solutions include re-grounding the electrical panel to a different approved ground. Grounding the pipes to a grounding rod has also fixed this type of problem in some instances.

Recirculating Hot Water Systems
These systems often result in copper stains that are only observed in rooms served by the system (and only in the hot water). Installing a phosphate cartridge in the loop can often alleviate this problem. The phosphate puts a protective coating on the pipes.

Sulfide (the “rotten egg gas” is hydrogen sulfide) will corrode copper, but usually does not result in blue-green stains. Instead, the sulfide combines with the copper (and other metals) to form a black powder with the consistency of soot. The black material often settles in hot water heaters and may be observed when the heater is drained.

Dissolved Gases
Water sometimes contains dissolved gases, such as carbon dioxide, methane, or oxygen that may influence metallic corrosion. Some type of aeration system can often alleviate these problems. In fact, aeration is one means of treating acidic water, because the acidity is often associated with excess carbon dioxide.

The recommended drinking water limit for lead is 15 µg/L (0.015 mg/L). Lead in drinking water is usually the result of the effects of corrosive water on lead-containing solder and brass. Consumption of low levels of lead over a long period can have adverse health effects, especially upon children.

Lead Levels:

  • Low: 5-10 µg/L
  • Moderate: 11-15 µg/L
  • High: >15 µg/L