Colmar, Grand Est, France

What was done

Colmar Agglomération (20 communes, ~110,000 inhabitants, Haut-Rhin, France) distributes laying hens to households as a source-diversion measure within its household-waste prevention plan. It has run annually since 2015 — the 12th edition, on 23 May 2025, distributed 840 hens to 420 households.

How it works

• Households with a coop and 8–10 m² of outdoor space apply in advance. Each application is checked against a participation charter, may include an on-site coop inspection, is one per household, and renewable every two years.
• Selected households receive two hens (~4 months old), a starter bag of grain, and an "adopter's booklet" with husbandry guidance.
• The authority keeps a record of every participating household and follows up.
• Run as a complement to — not a replacement for — the agglomeration's curbside biowaste collection.

Results

• Measured impact: the operator estimated ~70–80 tonnes/year of biowaste diverted via the hens (2019), against ~4,800 tonnes/year collected curbside — roughly 1.5% of the authority's biowaste. Real but modest.
• Scale builds by accumulation: ~1,200 participating households by end 2018; 6,066 hens distributed in total 2015–2025, from annual cohorts of 300–840.
• Cost: ~€25 per pair of hens, co-funded by the agglomeration and member communes; ADEME subsidises communication.
• Consistently oversubscribed; recipients value the eggs as much as the waste reduction.

What a replicating commune should know

• Budget for staff time, not just hens. The €25/pair is minor; charter checks, coop inspections and follow-up are the real recurring cost.
• Size expectations realistically — this diverts a low-single-digit percentage of biowaste, so treat it as one channel among several, not a primary route.
• It only fits households with gardens; it cannot cover apartments or dense urban cores.
• Welfare safeguards (charter, space minimum, inspection, booklet, per-household follow-up) are what let the authority credibly claim hens are not being abandoned. Predation by foxes in semi-rural areas is an unavoidable loss.
• Headline per-household figures (~100 kg/year) are capacity estimates; commit to measuring real diverted tonnage, and re-measure as the installed base grows. Colmar's measured figure dates from 2019 and has not been refreshed.