COPPER CORROSION IN WATER

Copper corrosion in domestic water supplies is normally associated with soft, low pH (acidic) water leaching copper from internal piping and hot water cylinders.

Any water with a pH of 7 or below can be liable to corrosive properties and this is generally associated with pure soft spring water or rain water that has been held in plastic or fiberglass tanks.  There is seldom high naturally occurring copper levels in ground water and none in rain water, in almost all cases it is caused by leaching from contact with pipes and containers.

VISABLE SIGNS

Blue/green discoloration of baths, showers, white wear etc.

Green toning of light coloured hair

Lingering bitter metallic taste in water

Copper pipes and cylinders pitting, springing leaks, breaking and weeping a blue/green stain.

TOXICITY

Maximum allowable health level 2ppm

Symptoms of poisoning may show up well below that level, some people appear more susceptible than others and may show adverse effects as low as 0.5ppm.

SYMPTOMS OF ADVERSE REACTION

Symptoms seem to vary widely between individuals drinking from the same source and can include amongst others.

Diarrhea, vomiting, general lethargy and feeling unwell, loss of appetite.  There is also anecdotal evidence that it may be an influence in some cases of early miscarriage.

Bacterial contamination can cause some similar symptoms but in the case of copper the onset can often be within a few minutes of ingestion whereas bacterial effects usually take 6 – 24 hours to take effect.

The greening affect of hair is from the external effects of washing in water containing copper, not from ingestion.  It would appear that some soaps and shampoos can magnify the effects.

VERIFYING Cu LEVELS

A simple copper level test can be done on the supply.  Take samples from both the hot and cold outlets as there can be huge variation between both systems.  This is due to fact that hot water cylinders are normally made from copper, the water lies in contact for much longer and heating accelerates the reaction time.  There can also be big variation between taps on the same supply source due to some leads being piped in non reactive material like polybutlene and others in copper.  The amount of time the water has lain in the pipe can also have an effect.

SOLUTIONS

It is much easier to keep copper out of water than it is to remove it from a supply once it is in there.

If you can neutralize the water (raise the pH above 7) before it comes in contact with copper then there will be no corrosion and no elevated Cu levels.   This is easily achieved by passing the water through a bed of neutralizing media prior to contact with copper, the resulting pH is usually around 7.5 to 8.

Once the copper is dissolved into the water it will not be removed by boiling or passing through normal household carbon purifiers, it will have to be passed through a reverse osmosis unit or distiller.

The downside to these methods is that all impurities and minerals are removed and the water will then aggressively try and buffer itself again by absorbing minerals and salts from the body (especially calcium).  Continual drinking of distilled water can be a contributing factor towards osteoporosis, tooth decay etc.