Greywater, Worms & Mushrooms: Okines Garden System by Milkwood
TL;DR: This case study details an integrated greywater, worm farm, and mushroom system for on-site organic waste treatment and nutrient recycling, ideal for community gardens or off-grid living.
- Greywater system, worm farm, and mushroom garden integrated.
- Treats kitchen greywater, produces fertilizer and food.
- Low-tech, uses recycled materials, cost-effective.
- Reduces BOD 70-90%, prevents clogging.
- Modular design, scalable for various settings.
- Example of permaculture sectoring and stacking functions.
Why it matters: This system offers a practical solution to manage organic-rich greywater on-site, converting a waste stream into valuable resources like fertilizer and edible mushrooms. It improves soil health and reduces reliance on external inputs, creating a more self-sufficient and resilient system.
Do this next: Assess your greywater output and available space to determine if a similar integrated system is feasible for your home or community garden.
Recommended for: Homeowners, community garden managers, and off-grid enthusiasts looking for sustainable greywater management and resource production.
This integrated permaculture system combines greywater treatment, worm farming, and mushroom cultivation into a single stacked-function unit, demonstrated at Okines Community Garden for their outdoor kitchen sink. Guest designer Nick Ritar from Milkwood optimized it for nutrient-rich greywater from food prep, creating a low-tech grease trap and bioreactor in a recycled bath. Process: sink plumbed outdoors to bath filled with woodchips inoculated with mushroom spawn (e.g., oyster mushrooms) for 1-month priming, then populated with compost worms. Greywater flows in, worms process organics into castings, mushrooms break down lignin/grease, effluent percolates through to garden via overflow or dripline. Specs: bath 1.5m x 0.7m, 20-40cm woodchip depth (5-20mm chips), 1kg spawn, 2kg worms for 50-100L/day. Retention 24-48 hours yields clear leachate (BOD reduced 70-90% visually), castings harvested monthly as fertilizer, spent substrate as mulch. Cost: $50-100 using scavenged materials. Performance: handles high-organic loads without clogging, boosts garden yields via worm tea. Stacking benefits: worms thrive in moist, nutrient-dense conditions; mushrooms colonize chips pre-worm arrival; greywater irrigates below. Installation: level bath, inlet pipe at high end, overflow at low; prime chips moist for spawn run. Maintenance: top up chips/worms seasonally, monitor pH (6-7 ideal). Scaled from tinyhouse to community, teaches permaculture sectoring (Zone 1 kitchen to treatment). Challenges: grease via preclearer; odors prevented by carbon-rich media. Practitioner insights: integrate with banana circles for tropics; test for salinity; yields quantifiable—e.g., 10kg castings/year per unit. This case provides replicable steps for multi-function waste processing, enhancing resilience in off-grid or urban settings with detailed material lists, timelines, and troubleshooting for real-world deployment.