Permitted discharge to soil/drainage field

Where reuse isn't practical, treated greywater is released to a code-compliant drainage field. Gravity-fed and genuinely passive where the site gives enough fall; on flat ground or where flow has to rise, a pump is needed and it is no longer passive.

Cost
Low
Upkeep
Seasonal
Lifespan
Drainage field: 20-30 years before soil clogging ("biomat") reduces infiltration and the field needs rest or replacement
Embodied carbon
Low
Space / material use
Low
Output timing
Continuous process
Skill to repair
Intermediate
Regulation (FR example)
On-site sanitation (assainissement non collectif): the installation must be declared to and approved by the local SPANC before work starts, and is subject to periodic inspection. Arrete du 7 septembre 2009 modifie.

Note: Cost, carbon and footprint are rated against the other options for this same need, not in absolute terms.

What your site needs

Soil percolation rate and area sufficient for a code-compliant drainage field, plus enough fall from the outlet to the field to avoid a lift pump

Inputs

Outputs

none

Sources

What this page does not tell you

No sizing or quantities: how much a technique yields, and how much a household needs, both depend on the build and the people, so the catalogue compares options rather than dimensioning them. It carries no bill of materials and no build sequence, and it is written for an oceanic, clay-soil climate (Normandy, France). Regulatory notes are indicative and need confirming locally.