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Water supplies on Coll

Just like Samuel Coleridge's famous line, 'water, water everywhere and not a drop to drink', water is around us but is often not clean or safe enough to drink.

Drinking water has always been an issue - outside of the village of Arinagour.

Arinagour is the only part of Coll that has serviced mains water (by Scottish Water) fed from their plant overlooking the village. All water outside the village is from private supplies and the degree of filtration/purification varies depending on the water source and cleansing apparatus used in treatment.

Traditionally, very few homes treated water, brown, peaty looking water was used for everything, including to drink.
Today, modern standards require all accommodation providers and holiday rentals pass an annual water purity test. Private homes are not included and only new builds need to pass 'the test' and then only once, during construction (renovations don't !).

Private water supply sources:

  • Burn (stream):
       Issues: bacteria, iron, manganese, tannin, acidity, reliability
  • Bore hole:
       Issues: bacteria, iron, manganese, acidity, high cost, risky
  • Spring:
       Issues: bacteria, iron, manganese, acidity, reliability
  • Rainwater harvesting:
       Issues: bacteria, acidity, storage space, sometimes it doesn't rain

Myths:
"Boiling 'brown' water makes it OK". It does not. Boiling will kill bacteriai/bugs but the water will still contain the same levels of heavy metals and acidity.

The issues:

  1. Bacteria and parasites such as E Coli(s) and Giardia (parasite associated with third world countries). Info on E Coli symptoms can be found here. Giardia symptoms and the fact it can remain in the gut for long periods, even after treatment, is of concern. It is a very serious parasite to endure.
  2. Iron and Manganese. Manganese is a more localised issue but iron is high in all Coll's burn water. Excess iron causes Haemochromatosis – affects liver, kidneys and the pancreas.
  3. Tannin is what makes burn water and lochs a brown colour. Tannin has no direct effect on health, it’s present in tea and wines. Tannins come from fermented organic materials that are created by the breakdown of vegetation, so the degree of ‘brown’ varies with the seasons. Even though directly innocuous, it plays havoc in blocking pipes, pumps and tanks and generates damaging suspended-flocculants when heated. It is the main cause of UV protection being compromised and that is why it should be in the discussion and eliminated from drinking water supplies.
  4. Acidity. Burn water and rain water are both extremely acidic. Typical burn water is pH 6.1 and rain water pH 5.8 (neutral is pH 7.0). Acidic hot water is even more ‘active’, in particular eating away at your plumbing's hardware.
    Health issue associated to acidic water are rare but acid water assists in the corrosion of teeth and can reduce the body's effectiveness in absorbing calcium, necessary for healthy bones. In contrast alkaline water can promote calcium retention, hence UK water regulations state that tap water pH should be between 6.5 and 9.5

Solutions:

  1. Bacteria etc: easily destroyed by UV light, commonly known as a UV filter. However, UV is attenuated by the 'brown' of tannin, so the water must be crystal clear.
  2. Iron & Manganese: difficult to remove. Only by using chemicals with regular back-washing, an expensive process. Simply boiling 'brown' burn water does NOT remove iron.
  3. Tannin: very difficult to remove and only needs to be removed as it inhibits all other types of filters (UV, iron, pH) from working effectively.
  4. Acidity: Relatively easy to neutralise by calcium carbonate based medium (e.g. Juraperle or even shell-sand from the beach).

The issues:

  1. Bacteria and parasites such as E Coli(s) and Giardia (parasite associated with third world countries). Info on E Coli symptoms can be found here. Giardia symptoms and the fact it can remain in the gut for long periods, even after treatment, is of concern. It is a very serious parasite to endure.
  2. Iron and Manganese. Manganese is a more localised issue but iron is high in all Coll's burn water. Excess iron causes Haemochromatosis – affects liver, kidneys and the pancreas.
  3. Tannin is what makes burn water and lochs a brown colour. Tannin has no direct effect on health, it’s present in tea and wines. Tannins come from fermented organic materials that are created by the breakdown of vegetation, so the degree of ‘brown’ varies with the seasons. Even though directly innocuous, it plays havoc in blocking pipes, pumps and tanks and generates damaging suspended-flocculants when heated. It is the main cause of UV protection being compromised and that is why it should be in the discussion and eliminated from drinking water supplies.
  4. Acidity. Burn water and rain water are both extremely acidic. Typical burn water is pH 6.1 and rain water pH 5.8 (neutral is pH 7.0). Acidic hot water is even more ‘active’, in particular eating away at your plumbing's hardware.
    Health issue associated to acidic water are rare but acid water assists in the corrosion of teeth and can reduce the body's effectiveness in absorbing calcium, necessary for healthy bones. In contrast alkaline water can promote calcium retention, hence UK water regulations state that tap water pH should be between 6.5 and 9.5

Solutions:

  1. Bacteria etc: easily destroyed by UV light, commonly known as a UV filter. However, UV is attenuated by the 'brown' of tannin, so the water must be crystal clear.
  2. Iron & Manganese: difficult to remove. Only by using chemicals with regular back-washing, an expensive process. Simply boiling 'brown' burn water does NOT remove iron.
  3. Tannin: very difficult to remove and only needs to be removed as it inhibits all other types of filters (UV, iron, pH) from working effectively.
  4. Acidity: Relatively easy to neutralise by calcium carbonate based medium (e.g. Juraperle or even shell-sand from the beach).

Click here for my personal in-depth appraisal of Coll private water supply issues.