Monthly Archives: September 2019

Autumn leaves in the city can contribute to poor water quality

Photo of Fayetteville, AR by Joe Wittkop (2014)

As we flip the calendar from September to October, we start to think about the beautiful autumn colors of the Ozarks. However, autumn leaves can actually contribute nutrients to our local waterways. This blog by Stephen A. Hubbs, professional engineer from Kentucky with the water quality and health council explains the connection between increased nutrients in our water and the autumn leaves which fall from our trees. Access the complete article here.

Today, a major concern is that leaf litter (i.e., organic debris) spikes stormwater systems and watersheds with nutrients during and after rainfall, especially when it gathers along street curbs. Excess phosphorus and nitrogen often lead to major water quality problems for municipalities, a process called eutrophication,1 and harmful algal blooms (HABs). The sources of nitrogen and phosphorus are many and varied, but leaves that fall on streets and into catch-basins during autumn can add to the nutrient problem in urban streams and lakes—particularly in subsequent summer months that also support conditions for HABs.

The connection between fallen leaves and excess nutrient loading may appear intuitive, but the impact on urban water quality, including release of organic compounds, is not fully understood. A U.S. Geological Survey researcher named William Selbig reported on research conducted during the months of April through November, 2013 to 2015, in Madison, Wisconsin.3 He noted that “While the sources of nutrients to urban stormwater are many, the primary contributor is often organic detritus, especially in areas with dense overhead tree canopy … making source control through leaf removal one of the few treatment options available to environmental managers when reducing the amount of dissolved nutrients in stormwater runoff.”

So What Can I Do?

Think regionally (area streams and lakes) and act locally (your front yard). There are several things you can do this fall to reduce the effect of leaves on urban water quality:

  • Consider mulching in-place with your lawn mower, especially if your yard is relatively flat, and those nutrients will soak into your lawn.4 And it’s probably easier than raking!
  • Gather leaves and other “yard waste” into a compost pile for use next spring to fertilize flower beds and vegetable gardens.
  • If you know when leaves will be collected for your community, wait to rake them close to the street until just before collection time.
  • If you have curbside leaf collection, rake leaves near the edge of the street (keep about three feet of lawn between the curb and the pile) but not into the street. The soil under the leaves will adsorb some of the nutrients when it rains.
  • Keep leaves off driveways, sidewalks and other impermeable surfaces.
  • Keep the streets and catch-basins free of leaves … they usually lead straight to a stream!

Let’s Talk Trash…in our water!

It is often said the definition of insanity is doing the same thing over and over and expecting different results. I don’t know that we necessarily expect different results by conducting stream and watershed cleanups over and over because we expect to find trash and we become happy or even concerned if we go back to a known location over time and see less trash. It leaves us wondering, “where did the trash go, now?” So maybe this endless cycle of cleanups means we are more insane for not expecting different results!!

But, one thing is becoming more clear, our trash is following our water cycle! There have even been recent reports of microplastics being identified in rain water, indicating plastics are possibly falling out of the atmosphere during rainfall.

So, despite our best efforts to clean up at least some of our streams and watersheds, we continue to find more trash, meaning the cleanups are just part of the cycle and not directly addressing the trash problem. Meanwhile, the trash and plastic problems in the oceans persist and grow.

Sydney Harris, ORISE at U.S. Environmental Protection Agency, United States, Toward a standard trash assessment method

Trash in waterbodies is not assessed and regulated in most states. However, over 200 individual water body reaches in 7 states including Alaska, California, Connecticut, District of Columbia, Hawaii, Maryland, and New York have been listed as impaired for trash, debris or floatables since 1996. But, most states or localities have little accounting for how much trash is being accumulated in streams or the efforts underway and costs to clean up trash out of streams.

Escaped Trash Assessment Protocol

A new effort is underway to standardize how we conduct cleanups and account for the trash that is found through the Escaped Trash Assessment Protocol. The Escaped Trash Assessment Protocol was created by the Trash Free Waters Program (TFW) of the United States Environmental Protection Agency (U.S. EPA). A pilot project, featured in the May 2019 EPA Newsletter The Flow…of Trash Free Waters, is currently underway on Three Mile Creek in downtown Mobile, Alabama using the Litter Gitter system and the Escaped Trash Assessment Protocol to collect data about the trash found in the creek and provide feedback on the protocol.

DRAFT Escaped Trash Assessment Protocol (ETAP)

The protocol follows a 4-step process:

Step 1: Site Selection – In this step you will select a site and identify specific boundaries for your cleanup and study.

Step 2: Site characterization and cleanup – In this step you will identify your landuses, existing trash condition, existing preventative measures for trash management, and distance to waterbody. You will conduct a cleanup and catalogue the trash using the datacard.

Step 3: Data Entry and Analysis – In this step you will enter and analyze your data to better understand and describe the trash, conditions, and metrics from your cleanup.

Step 4: Adaptive Management – Propose adaptive management strategies to address localized trash problems.

Benefits of a standardized method

The benefits of having and following a standard protocol are numerous to watershed management.

  • The methods can be implemented across all environments.
  • Results can be compared across states and watersheds.
  • Watershed organizations can use the data to prioritize areas for adaptive management or to implement BMPs rather than endlessly expending resources on conducting cleanups.
  • Data can be visualized and explained to the public and other stakeholders.
  • Long-term data can be collected and analyzed in a methodical way to determine trends of a specific area over time.
  • Upstream and Downstream data can be used to identify inputs of trash or to analyze effectiveness of implemented BMPs.
Sydney Harris, ORISE at U.S. Environmental Protection Agency, United States, Toward a standard trash assessment method

To learn more about efforts to reduce trash, visit Trash-Free Waters at