Is UK stream water safe to drink?

No UK water source should be considered safe without treatment. Even clear mountain streams can contain Giardia, Cryptosporidium, and bacteria from sheep and cattle. Dead animals, agricultural runoff, and human waste can contaminate even remote sources. Always purify water collected from natural sources.

What is the best water purification method for hiking?

A combination of filter + chemical treatment gives the broadest protection. A squeeze filter (like Sawyer) removes bacteria and protozoa instantly, while a chlorine dioxide tablet added afterwards kills viruses. For UK hiking where virus risk is low, a filter alone is usually sufficient.

How many purification tablets should I carry?

Carry enough tablets for your total water needs plus 50% extra. For 2 people over 3 days at 3L each per day, that is 18L = 18 tablets minimum, so carry at least 27. Tablets are very light, so carrying extras is cheap insurance. Always check expiry dates.

Can I drink rainwater?

Fresh rainwater collected directly (not from roofs or other surfaces) is generally safe to drink without treatment, though it contains no minerals. In practice, collecting enough rainwater while hiking is difficult. It is better to collect from flowing streams and treat the water properly.

CampCalcs

Water Purification Calculator

Calculate purification tablet or filter capacity needs for your trip duration.

Number of People

Trip Days

Litres per Person/Day

Purification Method

Water Clarity

How We Calculate This

Water Requirement

Total water = People x Days x Litres per day

Treatment Methods

Tablets: 1 tablet per litre (double for murky water). Filter: pump/squeeze required volume. UV: 60-90 seconds per litre. Boiling: ~20g fuel per litre.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify conditions and use proper safety equipment outdoors.