Find salt springs and licks by following animal trails to a spot where deer, elk and livestock congregate, looking for white mineral crusts on rock and soil, and tasting the water, then measure how strong the brine is before investing fuel in it. A spring at 20% needs about a ninth of the water evaporated per pound of salt that seawater does, but a spring at 1% needs nearly three times as much, so the strength of the brine decides whether it is worth boiling.
Part of Salt Production & Sourcing
A salt spring or lick is a natural outflow where groundwater has dissolved underground salt, producing brine of widely varying strength that animals seek out and people can boil down.
How To Find One
The parent article gives the signs:
- Animal activity. Deer, elk and livestock travel miles to salt licks. A place where wildlife congregate is a place to check for salty water or soil.
- White mineral deposits on rocks or soil near the spring.
- Taste. The parent says salty springs are unmistakable. Taste a drop of the water only from a source you have judged safe to touch, spit it out, and wash your mouth.
Springs vary from very weak (1-2%) to nearly saturated (20%+), according to the parent. Where the brine is weak, concentrate it by boiling as for seawater.
Strength Decides The Fuel Bill
Per kilogram of sodium chloride recovered, the water to evaporate is (100 − c) ÷ c kg, for a brine of c percent salt. Computing it:
| Brine strength | Water to evaporate per kg of salt |
|---|---|
| 1% | 99 kg |
| 2% | 49 kg |
| 5% | 19 kg |
| 10% | 9 kg |
| 20% | 4 kg |
| Saturated, about 26.4% | 2.8 kg |
| Seawater, about 2.74% sodium chloride | 35.5 kg |
(Saturated strength 26.4% comes from 35.9 g of salt per 100 g of water, recalled; the seawater figure comes from the sodium chloride share worked out in Seawater evaporation.)
From the table, a 20% spring needs 4 ÷ 35.5 = 11% (about a ninth) of the seawater fuel. A 1% spring needs 99 ÷ 35.5 = 2.8 times as much as seawater. A 2% spring needs 49 ÷ 35.5 = 1.4 times. So the parent’s “weak” springs at 1-2% can cost more fuel than seawater, and are worth using only if the sea is far away. A strong spring is the cheapest salt there is (Brine Boiling).
What You Need
- A way to measure the brine’s strength. The floating-egg test is a rough guide (Brine Strength). A better one is to evaporate a measured volume to dryness and weigh the salt.
- Clean containers for sampling
- A means to protect the spring from animals and runoff
Method: Survey A Spring
Step 1: Look for the signs and note the flow: how many litres a day.
Step 2: Judge safety: what is upstream, what stock walk through it (Source Risk Rating).
Step 3: Take a measured sample, evaporate it slowly to dryness and weigh the residue to find the strength.
Step 4: Compare with the table to decide whether boiling is worthwhile.
Step 5: If it is, fence the spring and build a collection basin.
Common Mistakes
- Boiling every salty seep. A 1% brine can cost more fuel than seawater.
- Assuming a lick is clean. Animals foul it with droppings.
- Taking the strength by taste. A strong taste does not give a number.
Safety
Natural brine can carry what the ground carries
Springs can carry heavy metals, arsenic, hydrocarbons or radioactive minerals, especially near mines, oil seeps and old workings, and boiling concentrates them rather than removing them. Droppings from the animals that use a lick carry disease. If the brine has an oily sheen, a petrol or sulfur smell, a rust-coloured or unusual colour, or comes from near a mine or industrial site, do not make food salt from it. See Water Testing: Assessing Water Safety for the limits of field tests.
What’s Next
- Learn next: Brine Boiling — boiling brine down to salt
- Combine with: Brine well construction — reaching brine that does not reach the surface