Zero Waste Washington conducts research in order to demonstrate needed changes and spur further action.

Here are some of our recent research projects.

The State of Residential Recycling and Organics Collection in Washington State

In November 2019, Zero Waste Washington published a report – The State of Residential Recycling and Organics Collection in Washington State – written by our UW fellow, Nicolás M. Díaz Huarnez. We found that residential recycling and organics collection is highly variable across the state, with the most robust service available in the Puget Sound region.


Some highlights:

  • Residential curbside recycling collection is available in 58% of jurisdictions and organics collection is available in 49% of jurisdictions in Washington.
  • 57% of local jurisdictions accept plastic bottles at curbside and an additional 21% accept them at drop-off stations and boxes.


This report described the state of residential recycling and organics curbside and drop-off collection programs administered by local governments in Washington State. Specifically, the study compiled existing information about service areas, providers, frequency and type of collection, lists of accepted materials, and available drop-off locations. We examined online materials for jurisdictions and associated service providers, including digital pamphlets, lists of prices and materials, handling instructions, associated UTC permits, and current solid waste management plans. We also interviewed key actors in Washington’s recycling system to obtain their impressions, perspectives, and opinions about challenges and potential policy solutions.

For a summary, see the Publications page.

PFAS in compost

Zero Waste Washington partnered with a research team at Purdue University to research toxic chemicals called per- and polyfluoroalkyl substances (PFAS) in commercial compost samples from Washington, Oregon, California, Massachusetts and North Carolina. This study demonstrated that our commercial composts which receive mixed food and yard waste and compostable food serviceware have levels of PFAS that are much higher than those without the compostable food serviceware.

This means that our paper plates, pizza boxes, and french fry sleeves are adding PFAS to our commercial compost. The levels of PFAS are high enough to potentially be a concern because the toxic chemicals may move from compost into stormwater or groundwater when it rains, potentially entering drinking water. For a summary, see Publications page.

Phthalates in Products

Zero Waste Washington is working with partners on a project to identify and reduce the largest sources of phthalates from outdoor products in proximity to two Superfund sites in Puget Sound. Phthalates are a class of chemicals that primarily serve the function of carrying scents or making plastics flexible, transparent, or durable. Unfortunately, they are easily taken up by humans and wildlife, and they are associated with numerous health problems, notably reproductive health.

We are testing outdoor products (such as exterior paint, traffic cones, outdoor signage, etc.) for phthalate concentrations. The goals are to reduce phthalates input into stormwater, improve source control and reduce impacts to humans.