Overview
EN ISO 8099-2:2021 (ISO 8099-2:2020) specifies requirements for the design, construction and installation of sewage treatment systems on small craft (recreational boats and similar watercraft up to 24 m hull length). The standard focuses on marine sewage treatment units and their associated plumbing, venting, alarms and installation practices.
It explicitly does not cover waste retention systems, accidental discharge prevention of other pollutants (e.g. oil, fuel) or the definitive regulatory discharge limits for treated effluent (these are subject to national or international regulations).
Key topics and technical requirements
- Scope and definitions: Clarifies terms such as sewage (black water), sewage treatment unit, holding tanks and accessibility requirements.
- Design and installation: Requirements to prevent vapor or liquid emission into the craft; toilets to be connected only to a holding tank (ISO 8099-1) or a treatment system.
- Environmental and operational limits:
- Operation temperature range: +1 °C to +50 °C; storage range −40 °C to +60 °C.
- Operation while heeled: discharge must function at 20° heel for monohull sailing craft and 7° for other craft.
- Back-siphoning and trim resistance:
- Prevent back siphoning to at least 30° heel (monohull) and 20° (other craft), and 10° trim fore/aft for raw water intakes, discharge outlets and sewage escape routes.
- Mechanical and pressure integrity:
- Piping, tanks and fittings must withstand 20 kPa positive pressure for 5 minutes without leaking.
- Systems that can experience negative pressure for pump-out must withstand −20 kPa for 5 minutes without permanent deformation.
- Safety and maintenance:
- Sewage treatment units must include a visible or audible alarm audible within habitable spaces.
- Provide a readily accessible, lockable means to disable discharge.
- Routine serviceable parts must be accessible in installed position.
- Units should be tested by a recognised laboratory (e.g., ISO/IEC 17025) against manufacturer-stated discharge performance.
Applications and who uses it
This standard is intended for:
- Boat builders and naval architects designing small craft waste systems.
- Sewage treatment equipment manufacturers developing units for marine use.
- Marine installers and shipyards performing fit-out and plumbing work.
- Certification bodies and testing laboratories evaluating system compliance.
- Owners and maintenance personnel using the installation and maintenance guidance.
Practical uses include specifying component selection (hoses, seacocks, vents), verifying installation practices, preparing owner/operator manuals, and ensuring systems meet EU/flag-state safety and environmental requirements.
Related standards
- ISO 8099-1:2018 - Small craft - Waste water retention (holding tanks)
- ISO 9093:2020 - Small craft - Seacocks and through-hull fittings
- ISO 13297:2020 - Small craft - Electrical systems (AC/DC installations)
- Relationship to EU Directive 2013/53/EU (see Annex ZA): meeting clauses of EN ISO 8099-2 can support presumption of conformity within the standard’s scope.
Keywords: EN ISO 8099-2:2021, small craft sewage treatment systems, marine sanitation, waste systems, sewage holding tank, sewage treatment unit, installation requirements.