Desalination
Only three percent of the Earth’s water is freshwater – the rest is mostly seawater, which is undrinkable for humans unless treated. Desalination is the process that makes seawater suitable for human consumption.
What’s desalination?
Desalination is a process that removes salt and minerals from seawater to produce drinking water.
Here are the key steps in the process:
- Abstraction – seawater is drawn in by an underwater pipe, which has a filter to stop fish and other sea-life getting in.
- Pre-treatment – chemicals are added that cause solids to stick together, so they can be filtered out.
- Desalination – the water is forced through a membrane with holes more than 50,000 times smaller than a human hair, so impurities like the dissolved salts are removed.
- Treated water conditioning – essential minerals are put back into the water and it’s treated to meet strict drinking water quality standards.
- Waste handling – anything removed is cleaned so the unused water can be returned to the sea and the solids can sent to landfill.
- Brine release – water removed during treatment has higher levels of salt, so it’s slowly released deep at sea where it will be more easily dispersed and diluted.
Find out more detail about each step of the process in the infographic below:
Our desalination plans
Desalination was our primary approach to help meet the water supply shortfall, as outlined in our ‘Water Resources Management Plan’ agreed with the regulator in 2019.
However, following a complex options appraisal process, the desalination plans have since been halted in favour of alternative solutions.
This is just one of our strategic solutions we have explored to address water shortages in Hampshire.