Biochar filtration systems
Managing runoff does not need to be complex or expensive.
Biochar filtration systems are used in specific contexts to reduce sediment, nutrients, and dissolved contaminants under defined hydraulic and chemical conditions.
Biochar filtration systems can be designed for reuse as a soil amendment – the whole system supports circular land management.
Why biochar filtration matters
Increasing regulatory pressure means many farms, estates, and rural sites now need clearer strategies for improving water quality. Although traditional options such as reed beds and lagoons help, they can be slow, land-intensive, or costly to maintain. Biochar filtration adds an efficient polishing stage that is compact, predictable, and easy to integrate into existing runoff pathways.
The biochar filtration approach links water quality, filtration performance, and soil-reuse considerations into one joined-up system.
Process Resources
Follow these steps to evaluate how (if!) biochar fits your needs
What Is a Biochar Filter?
A biochar filter is a water filtration system that uses biochar — a porous, carbon-rich sorbent — to remove nutrients from flowing water.
Is a Biochar Filter System Right For Your Water?
Before choosing any system, first check whether biochar biofiltration is appropriate.
Use our decision tree to identify your water type — agricultural, SuDS/surface water, highway runoff, industrial runoff, or CSO — and quickly confirm whether biochar is the correct technology.
Part 1: Water quality and regulations
Understand sediment, phosphorus, organic loading and EA risk levels so you can act early, before compliance issues escalate.
This section explains why filtration matters, the typical regulatory triggers, and how biochar supports more consistent outcomes in agricultural and surface-water settings.
Part 2: Filtration systems and design
Biochar works best in simple filter beds designed to operate under stable, low-stress conditions, supported by gentle pre-treatment.
This section covers system layouts, flow paths, particle-size logic, biofilm behaviour, maintenance expectations, and why designs prioritise soil-safe operation over metals-polishing performance.
Part 3: Soil reuse and carbon compliance
By design, biochar filters generate a material suitable for soil reuse, with the potential to contribute to structure, water retention, and long-term carbon stability when managed appropriately. This section explains PTE limits, mass-balance checks, soil-reuse frameworks, and the circular benefits of sending spent media back to land.
Frequently asked questions
Below are clear, practical answers to the questions land managers ask most often.
You can find the full FAQ library in the main menu.
How do biochar filters help reduce compliance risk?
Biochar captures fine sediments, organic matter, and nutrients, which are commonly linked to EA warnings and formal notices.
What contaminants can a biochar filter remove?
Biochar is highly porous and removes suspended solids, nutrients (especially phosphorus), colour, odour, and dissolved organics. When paired with a pre-filter, overall performance improves significantly.
How often does the filter media need replacing?
Most systems run for several months before change-out, although this depends on sediment load and site conditions. Replacement media is lightweight and easy to handle.
What happens to the media after use?
It is repurposed as a value-added soil amendment. The biochar–organic matrix supports soil structure, moisture retention, and carbon balance.
Early case-study development
Farms and estates are testing various types of biochar filtration systems. These early projects will demonstrate practical layouts, operational performance, and soil-reuse outcomes.