UK Building Control: https://buildingcontrol.planningportal.co.uk/

General Binding Rules: https://www.generalbindingrules.co.uk/general-binding-rules

Environment Agency Regulations: https://www.gov.uk/guidance/general-binding-rules-small-sewage-discharge-to-the-ground

British Water Guidelines: https://www.britishwater.co.uk/page/Accreditation-Certificationcertified-small-wastewater-treatment-systems-for-up-to-50-pt

Septic Tank Discharge Regulations: https://consult.defra.gov.uk/water/reform-regulatory-system-small-sewage-discharges/results/your-sewage-your-environment-leaflet-july-2015.pdf

British Water Flows and Loads: https://www.septictank.co.uk/british-water-flows-and-loads.pdf