Navigating Seattle's Curbside Food Waste Composting Rules

Understanding Seattle’s Curbside Composting Program

Seattle leads in waste diversion, with its robust organic waste composting service playing a crucial role in achieving the city’s sustainability goals. This service allows residents to divert organics from landfills, preventing methane production, a potent greenhouse gas. Instead, these materials become nutrient-rich compost, benefiting local agriculture and landscaping. Understanding what’s accepted and prohibited ensures your efforts contribute positively to this cycle, minimizing contamination and collection issues.

The program is designed to be comprehensive, accommodating a wide range of organic waste generated in households. Properly using your green composting cart not only reduces your carbon footprint but also supports the local economy by providing valuable soil amendments.

The Definitive ‘YES’ List: What Goes In Your Seattle Compost Cart

Seattle’s organics collection guidelines are quite inclusive, simplifying composting for most kitchen and garden waste residents generate. Generally, if it was once alive, it likely belongs in your green cart.

All Food Scraps Welcome

Unlike some programs, Seattle accepts all food scraps, cooked or uncooked. This includes:

• Fruits and Vegetables: Peels, cores, scraps, spoiled produce.
• Meats and Poultry: Bones, skin, gristle, including small animal bones.
• Seafood: Shells (crab, shrimp, oysters), fish scraps.
• Dairy Products: Cheese, yogurt, sour cream (liquid milk should be avoided in large quantities).
• Grains and Baked Goods: Bread, pasta, rice, cereals, pastries.
• Eggs: Shells and contents.
• Coffee Grounds and Filters: Paper filters are acceptable.
• Tea Bags: Including staples (most are compostable).
• Fats, Oils, and Greasy Foods: Small amounts absorbed by paper towels or newspaper.

Yard Waste Essentials

Your green cart is also for yard debris. This includes:

• Leaves and grass clippings.
• Weeds and garden trimmings.
• Small branches and twigs (less than 4 feet long and 4 inches in diameter).
• Untreated, unpainted wood scraps.
• Houseplant trimmings and potting soil (in small amounts).

Certified Compostable Products

This category is crucial. Only products certified by the Biodegradable Products Institute (BPI), clearly displaying the official BPI logo, are acceptable. Examples include:

• BPI-certified compostable bags (often used for kitchen pails).
• BPI-certified compostable plates, cups, and cutlery.
• Food-soiled paper products: pizza boxes (remove plastic liners), paper napkins, paper towels (soaked in food/grease), uncoated paper plates.

The Absolute ‘NO’ List: Prohibited Items to Keep Out

Contamination poses a significant challenge for composting facilities. Introducing non-accepted materials risks cart rejection and can compromise the final compost’s quality. When in doubt, leave it out.

• Plastics: Absolutely no plastic bags (even if labeled ‘biodegradable’ unless BPI-certified), plastic containers, wraps, films, or foam packaging.
• Glass, Metal, and Aluminum: Bottles, jars, cans, aluminum foil, or other metals.
• Styrofoam: Any type of Styrofoam, including cups, plates, or packaging peanuts.
• Pet Waste: Cat litter, dog feces, or any animal waste. This is a significant contaminant due to pathogens.
• Diapers: Both disposable and cloth diapers.
• Hazardous Waste: Chemicals, batteries, paint, motor oil.
• Treated Wood: Lumber, plywood, particleboard, or any wood that has been painted, stained, or pressure-treated.
• Liquids: Large quantities of liquids, including excessive oils or soups, should not be poured directly into the cart.
• Waxed/Coated Paper: Milk cartons, juice boxes, or heavily waxed cardboard unless explicitly BPI-certified as compostable.
• Non-BPI Certified ‘Biodegradable’ Products: Many products claim to be ‘biodegradable’ but are not suitable for Seattle’s commercial composting facilities. Always look for the BPI certification logo.

Optimizing Your Composting: Best Practices for Seattle Residents

Achieving smooth and effective composting involves a few simple habits and choices.

Using Your Kitchen Pail and Liners

A small kitchen pail is ideal for collecting food scraps indoors. To manage odors and keep your pail clean, use BPI-certified compostable bags. If you don’t have a liner, you can also line the bottom of your pail with newspaper or paper towels to absorb moisture.

Odor and Pest Management

• Freeze Scraps: For particularly odorous items like meat or fish, freeze them until collection day.
• Layering: Place a layer of yard waste (like leaves) at the bottom of your cart, then alternate food scraps with more yard waste.
• Close the Lid Tightly: Always ensure your green cart lid is securely closed to prevent pests and contain odors.
• Regular Emptying: Empty your kitchen pail frequently, especially in warmer months.

Common Composting Mistakes to Avoid

To avoid issues with your organics collection, be mindful of these common errors:

• Using non-certified ‘biodegradable’ or conventional plastic bags instead of BPI-certified compostable bags.
• Including pet waste (cat litter, dog feces), which is a major contaminant in Seattle’s program.
• Placing liquids, excessive oils, or messy food scraps directly into the cart without using liners or absorbing solids, leading to odors and sticking.
• Composting non-food-soiled paper products like glossy magazines, waxed cardboard, or coated paper coffee cups (unless BPI-certified).
• Forgetting to tightly close the compost cart lid, attracting pests or leading to spilled contents.

Decision Checklist: Is It Compostable in Seattle?

Before you toss, quickly review these questions to ensure your item is Seattle-approved:

• Is it 100% food waste (including meat, dairy, bones, or cooked food)?
• Is it yard waste (leaves, grass, small branches, untreated wood)?
• Is it a BPI-certified compostable product (bag, cup, utensil) with the BPI logo clearly visible?
• Have all plastic, glass, metal, Styrofoam, and non-certified packaging been removed?
• Is the material free of pet waste, human waste, or medical waste?

If you answered ‘yes’ to any of the first three and ‘yes’ to the last two, it’s likely good to go!

How to Verify in Seattle Today

Staying current with composting guidelines is important, as rules can occasionally be updated. Here’s how to quickly verify information specific to Seattle:

1. Seattle Public Utilities (SPU) Website: The official SPU website (www.seattle.gov/utilities) is the primary and most reliable source for current food and yard waste collection guidelines. Navigate to their ‘Compost’ or ‘Food & Yard Waste’ sections.
2. Contact SPU Customer Service: If you have specific questions about an unusual item, call Seattle Public Utilities customer service directly. Their representatives can provide precise, up-to-date guidance.
3. Check Your Waste Hauler’s Website: Seattle’s waste collection is managed by specific haulers depending on your location (e.g., Waste Management, Republic Services). While SPU sets the overall rules, checking your specific hauler’s website can sometimes offer additional tips or local collection schedules. Ensure their guidelines align with SPU’s overarching policy.

Frequently Asked Questions (FAQ)

Q: Can I compost meat, bones, or dairy products in Seattle?

A: Yes, entirely! Seattle’s program accepts all food scraps, such as meat, poultry, fish, bones, and dairy products. This comprehensive acceptance is a key feature of Seattle’s organic waste system.

Q: Do I need special bags for my kitchen food scraps?

A: Yes, if you use bags, they must be certified compostable by the Biodegradable Products Institute (BPI) and display the BPI logo. Regular plastic bags, even thin ones, are not accepted.

Q: What about products labeled ‘biodegradable’ or ‘compostable’ without the BPI logo?

A: These products should generally be avoided in your green cart. Only items with the official BPI certification logo are designed to break down effectively in Seattle’s commercial composting facilities. ‘Biodegradable’ claims often refer to conditions not met by industrial composting processes.

Q: Can I put pet waste, like dog poop or cat litter, into my compost bin?

A: No, pet waste is strictly prohibited in Seattle’s curbside compost program. This is due to potential pathogens that can contaminate the finished compost. Please dispose of pet waste in the regular garbage bin.

Q: My compost cart smells bad. What can I do?

A: To reduce odors, try layering food scraps with yard waste or newspaper, freezing particularly smelly items until collection day, and ensuring your cart lid is tightly closed. Using BPI-certified liners in your kitchen pail also helps maintain cleanliness and reduce odors.