I have been trying to find a list of water sources that should be avoided. I have checked online and looked at several water companies, e.g. Scottish Water. I haven't found any information on which rivers, lochs (lakes) or streams that should be avoided.

Some of these can have raw sewage, factory or farmland pollutants further upstream. I know one river in particular that all the locals advise not to drink from, regardless of how much purification is done on the water.

I use a water filter and/or boiling and if required carry iodine in my survival pouch.

Most of the time I rough camp in the hills and mountains so I know from a geographical point that the water I use doesn't have any "external" pollutants.

  • All things considered, you should still treat water in the UK if it doesn't come from a tap - but the biggest thing I've always experienced is if the water is hard or soft, as suddenly switching to one can cause some people stomach upset even though there is nothing polluting the water. Frankly, with rivers it'll be a case of location, Thames in Oxfordshire is better than Thames in London.
    – Aravona
    Commented Sep 27, 2019 at 14:11
  • 1
    I'd be surprised to find such source. Rivers or big lakes can be very different depending on where exactly you are. Upstream/closer to the source will be better than downstream after passing through few cities.
    – pbm
    Commented Sep 27, 2019 at 14:54
  • I would never drink from rivers or lakes. Even a mountain stream can be polluted by a dead sheep further up. Only drink from springs. Commented Sep 27, 2019 at 15:57

1 Answer 1


No one is going to guarantee that a water source is safe to drink from. The best you can do is look for reasons that a given water source might be expected to be unsafe. Then, after you rule out as many sources of risk as you can, you make your own determination whether that water source seems safe enough to you.

Personally, I like to use a topographic map to figure out where the headwaters of a given stream is. I try to get water from as close to the headwaters as possible. And I look at the land use of all of the stream upstream from where I'm taking water. Ideally, you would want to know about the historical land use, in case of any sources of groundwater contamination (old underground gas tanks, dump sites of mystery chemicals, mining, etc).

Keep in mind that filters remove microorganisms and undissolved particles. They don't do anything about dissolved chemical contaminants and heavy metals.

Here's a source of water quality testing testing in the UK:

UK Environment Agency Water Quality Archive

The Water Quality Archive provides data on water quality measurements. Samples are taken at sampling points around England and can be from coastal or estuarine waters, rivers, lakes, ponds, canals or groundwaters. They are taken for a number of purposes including compliance assessment against discharge permits, investigation of pollution incidents or environmental monitoring. The archive provides data on measurements and samples dating from 2000.

  • There's a sentence fragment in this answer - 'Consi'. It looks like you started to type a sentence with 'Considering' but got distracted. Figured you'd ought to know. Commented Oct 1, 2019 at 13:43
  • @Adonalsium That's exactly what happened. Thanks.
    – csk
    Commented Oct 1, 2019 at 17:39

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