Mycofilters

Basic Information

• Method Type: In-situ
• Primary Application: Stormwater/Agricultural runoff/Greywater
• Complexity Level: Beginner
• Installation Time: 1-2 weeks (including colonization time)
• Cost Range: $1,000-$2,000 per impervious acre per year

Overview

Mycofilters (also called mycosocks or bunker spawn) are burlap sacks stuffed with wood chips or straw and inoculated with mushroom mycelium. The mycelium acts as a biological filter, trapping and breaking down bacteria, sediment, and pollutants from stormwater runoff. Water passes through the mycelium network, which captures contaminants and transforms them into harmless carbohydrates and nutrients.

Knowledge Keepers & Intellectual Property

Traditional Knowledge & Indigenous Practices

Consider documenting cultural origins, traditional names in original languages, historical context and cultural significance, specific knowledge holders such as elders or cultural experts, cultural protocols for respectful attribution, and any ceremonial or spiritual aspects that should be respected.

Contemporary Knowledge Contributors

Paul Stamets pioneered this technology in the late 1980s and released it to public domain in 2015. Key research collaborations have involved Dr. Marc Beutel (environmental engineer at Washington State University), Alex Taylor (assistant researcher at Fungi Perfecti), Dusty Yao (co-director of Fungi Perfecti research), and research team members Alicia Flatt, M. Wolff, and K. Brownson. The technology received EPA funding and support from industry partners like Bill Taylor of Taylor Shellfish Farms. Community practitioners including the "mycokid" blogger and citizen scientists have adapted and refined the technique through DIY implementations. High school students from New Buffalo, Michigan have also contributed to field testing projects.

Intellectual Property Considerations

Mycofiltration technology is in the public domain as of 2015, with no patents restricting its use. Paul Stamets deliberately released his patent application to prevent others from patenting the technology in the future. The terms "mycofiltration," "mycofilter," and "mycorestoration" are also public domain. Proper attribution to Paul Stamets and the mycology community is encouraged when documenting or teaching the method.

How It Works

Target Pollutants

• E. coli and fecal coliform bacteria - Filtered and consumed by mycelium
• Heavy metals - Absorbed and sequestered by fungal tissue
• Petroleum products (diesel, oil, gasoline) - Broken down by mycelium enzymes
• Polycyclic aromatic hydrocarbons (PAHs) - Converted to fungal carbohydrates
• Excess nitrogen and phosphorus - Absorbed and incorporated into fungal biomass
• Sediment and silt - Physically trapped by mycelial networks

Key Organisms

• Stropharia rugoso-annulata (Garden Giant) - Primary species, most resilient for field conditions
• Pleurotus ostreatus (Oyster mushroom) - Effective for petroleum contamination
• Irpex lacteus - Shows promise in research trials

Site Requirements

• Space needed: Flexible - can be installed as individual socks or continuous berms
• Soil conditions: Adaptable to most conditions, benefits from some soil contact
• Climate considerations: Hardy in most temperate climates, mycelium can survive freezing and heat stress

Materials Needed

Biological Materials

• Mushroom spawn (grain or sawdust) - 1-2 lbs per sack - [Local mushroom suppliers or Fungi Perfecti]
• Stropharia rugoso-annulata preferred for resilience

Physical Materials

• Burlap sacks - Various sizes depending on application - [Feed stores, online suppliers, ULINE]
• Wood chips (hardwood preferred) - 2-4 cubic feet per sack - [Municipal arborists, tree services]
• Wheat straw (optional) - 1-2 bales - [Feed stores, farms]
• Biochar (optional) - Can enhance mycelial colonization and pollutant adsorption - [Biochar suppliers, can link to biochar page]

Tools

• Heavy-duty sewing needle and twine - For closing sacks
• Shovel or spade - For installation trenching

Safety

• PPE required: Gloves when handling spawn and organic materials
• Key risks: Minor risk of mold exposure during inoculation, physical strain from lifting heavy sacks
• Environmental precautions: Ensure spawn is from reputable supplier to avoid introducing invasive species

Installation Steps

Phase 1: Site Preparation

Step 1: Site Selection and Assessment

• Instructions: Identify water flow patterns and contamination sources. Choose locations where runoff naturally flows or can be directed through filters.
• Time: 1-2 hours
• Check: Water should flow through the area during rain events

Step 2: Material Preparation

• Instructions: Pasteurize wood chips if possible (optional but reduces contamination risk). Prepare burlap sacks by checking for holes.
• Time: 2-4 hours
• Check: Wood chips are damp but not waterlogged

Phase 2: Installation

Step 3: Inoculation

• Instructions: Mix mushroom spawn thoroughly with damp wood chips (and straw if using). Aim for 10-20% spawn by volume. Fill burlap sacks firmly but not too tight.
• Time: 1-2 hours per sack
• Check: Spawn is evenly distributed throughout substrate

Step 4: Sewing and Placement

• Instructions: Sew sacks closed with heavy twine. Dig shallow trenches where runoff occurs. Place sacks in trenches with good soil contact.
• Time: 30 minutes per sack
• Check: Sacks are secure and positioned to intercept water flow

Phase 3: Activation

Step 5: Colonization Period

• Instructions: Cover sacks with additional straw or leaves if desired. Keep moist but not waterlogged. Monitor for white mycelial growth.
• Time: 2-4 weeks for initial colonization
• Check: White mycelium visible on surface, no green mold contamination

Maintenance

• Weekly: Check for contamination (green mold), ensure adequate moisture
• Monthly: Remove any contaminated sections, add fresh organic matter if needed
• Signs of problems: Green mold growth, foul odors, lack of mycelial development

Troubleshooting

Problem: Green mold (Trichoderma) contamination

• Symptoms: Green fuzzy growth on surface of sacks
• Solution: Remove contaminated sections, spray with hydrogen peroxide, ensure better drainage

Cost Breakdown

• Materials: $50-100 per sack (spawn, burlap, wood chips)
• Tools/Equipment: $20-50 (basic tools)
• Total typical range: $200-500 for small installation
• Annual maintenance: $50-100 (replacement materials)

Resources

• Fungaia Farm mycofiltration products - [www.fungaiafarm.com/mycotechnologies]
• ULINE for burlap sacks and materials - [www.uline.com]
• Local mushroom cultivation groups - [Search for mycological societies]

Case Study

Burns Prairie, Michigan

• Scale: Pond edge installation to filter agricultural runoff affecting two ponds
• Results: Reduced algae growth in ponds, improved water clarity
• Cost: Under $500 for materials
• Key lesson: Proper placement in natural water flow patterns is crucial for effectiveness
• Project team: Mycokid blogger working with high school students from New Buffalo, in partnership with Chikaming Open Lands conservation organization

--- Last updated: June 24, 2025 | Page maintainer: Bioremmy