Q: Ammonium
A: A reduced nitrogen form that can be toxic at high levels and often converts to nitrate.

Q: Backwashing
A: Reversing water flow to remove trapped solids from filter media.

Q: Batch test
A: A laboratory test where media and solution are mixed to measure sorption performance.

Q: Biochar
A: A carbon-rich porous material produced by heating biomass in low oxygen, used for soil improvement, filtration and carbon sequestration.

Q: Biochar co-product soil amendment
A: Used filter biochar repurposed into soil to improve structure, biology and nutrient retention.

Q: Biochar filter
A: A treatment unit that uses biochar as the main media to remove contaminants from water or runoff.

Q: Biochar filter cartridge
A: A replaceable module filled with biochar media that slots into a filter housing.

Q: Biochar filter retrofit
A: Adding biochar media to an existing drainage or SuDS system to improve performance.

Q: Biochar media
A: Biochar granules, chips or pellets used as the active sorption material inside a filter.

Q: Biochar-humus composite (BHC)
A: An engineered blend of biochar and humus designed to enhance soil structure, biology and carbon stability.

Q: Biological Oxygen Demand (BOD)
A: The amount of oxygen microorganisms use to break down organic matter in water.

Q: Breakthrough
A: The point at which contaminants appear at the filter outlet because the media has reached capacity.

Q: Buffer strip
A: A vegetated strip that intercepts runoff before it reaches a watercourse.

Q: Carbon sequestration
A: Long-term storage of carbon in stable forms, such as biochar added to soil.

Q: Catchment
A: The land area that drains into a particular stream, ditch or water body.

Q: Catchment Sensitive Farming (CSF)
A: A programme supporting farmers to reduce agricultural pollution through advice and grants.

Q: Chemical Oxygen Demand (COD)
A: A rapid measure of oxidisable material in water using a chemical oxidant.

Q: C-STM (Callaghan Soil Transition Model)
A: A conceptual model describing interactions between compost, biochar and humus in soil.

Q: Co-product
A: A valuable secondary output produced alongside the primary product or service (e.g., soil amendment from biochar filters).

Q: Column test
A: A laboratory or pilot test where water flows through a packed media column to simulate real filter conditions.

Q: Compliance action
A: Steps taken to meet regulatory or permit requirements.

Q: Constructed wetland
A: A designed vegetated treatment system used to treat wastewater or runoff.

Q: Contact time
A: The time water remains in contact with filter media.

Q: Design loading rate
A: The amount of water or pollutant load used to size a filter during design.

Q: Desorption
A: Release of sorbed contaminants back into solution.

Q: Diffuse pollution
A: Pollution from scattered, non-point sources such as fields or tracks.

Q: EEAT
A: Expertise, Experience, Authoritativeness and Trustworthiness – Google’s content quality framework.

Q: Environment Agency (EA)
A: The environmental regulator for England responsible for water quality and permitting.

Q: Enforcement action
A: Regulator action taken when a site fails to comply with requirements.

Q: Eutrophication
A: Excessive nutrient enrichment leading to algal blooms and oxygen depletion.

Q: Farm assurance scheme
A: A quality certification scheme confirming environmental and welfare standards are met.

Q: Farmyard runoff
A: Contaminated water flowing from livestock areas, yards or tracks.

Q: Field drain
A: A subsurface pipe or channel draining water from fields.

Q: Filter bypass
A: A route that allows very high flows to bypass the filter to prevent media disturbance.

Q: Filter footprint
A: The area of land required for filter installation.

Q: Flow rate
A: The volume of water passing through a system per unit time.

Q: Full-scale deployment
A: Installation of a treatment system across an entire site after successful trials.

Q: Heavy metals
A: Toxic elements such as copper, zinc and lead that can harm soil and water systems.

Q: HOTBIN composter
A: An insulated aerobic composter operating at elevated temperatures.

Q: Hydraulic retention time (HRT)
A: Average time water spends in a treatment unit.

Q: Head loss
A: Pressure or water level drop across a filter due to flow resistance.

Q: Humus
A: The stable, long-lived fraction of soil organic matter formed through microbial transformation.

Q: Index P
A: UK soil phosphorus index used for agronomy and environmental risk evaluation.

Q: Interception filter
A: A filter installed in a drain or channel to intercept pollutants before they reach a watercourse.

Q: Leachate
A: Liquid percolating through silage, manure, compost or waste and dissolving contaminants.

Q: Leaching
A: Downward movement of soluble nutrients through soil.

Q: Media change-out trigger
A: The condition that initiates planned replacement of biochar media.

Q: Mineralisation
A: Microbial conversion of organic nutrients into inorganic plant-available forms.

Q: Multipurpose compost
A: General-purpose growing media used in gardening.

Q: NVZ (Nitrate Vulnerable Zone)
A: Areas with stricter nitrogen management regulations to protect water quality.

Q: Nitrate
A: A soluble nitrogen form that easily leaches into groundwater and surface water.

Q: PAS100 compost
A: UK-certified compost made to the PAS100 quality standard.

Q: Phosphate
A: A key nutrient that can cause eutrophication when overloaded in surface waters.

Q: Pilot trial
A: A limited on-farm test to validate filter performance and practical viability.

Q: Point source pollution
A: Pollution discharged from a single identifiable outlet like a pipe or culvert.

Q: PTEs (Potentially Toxic Elements)
A: Metals and metalloids that can harm soil, crops and aquatic life.

Q: Riparian zone
A: The land area adjacent to rivers and streams that stabilises soils and filters runoff.

Q: Runoff
A: Water flowing over land or through shallow pathways after rainfall, carrying sediment and nutrients.

Q: Service interval
A: The planned operational time or volume between inspections and maintenance.

Q: Settlement pond
A: A basin allowing suspended solids to settle out before treatment.

Q: Silt trap
A: A chamber designed to settle coarse sediment before water reaches a filter.

Q: Soil organic matter (SOM)
A: All organic materials in soil, from fresh plant residues to humus.

Q: S-STM (Soil Transition Matrix)
A: A framework comparing biological vs conventional soil management pathways.

Q: Sorption
A: Uptake of contaminants by a solid, including adsorption and absorption.

Q: Sorption isotherm
A: Graph showing how contaminants sorb onto media at different concentrations.

Q: Spent media
A: Filter media that has reached sorption capacity; reframed as a co-product for soil.

Q: SuDS
A: Sustainable Drainage Systems that manage rainfall using natural processes.

Q: Swale
A: A shallow vegetated channel that slows and filters runoff.

Q: Total suspended solids (TSS)
A: Undissolved particles carried in water contributing to turbidity.

Q: Water Framework Directive (WFD)
A: The legislation defining ecological and chemical objectives for water bodies in the UK.