Microplastics are everywhere. Are they in Sonoma County’s water?

East of Willowside Road, the Santa Rosa Creek is well maintained. For an often-used trail, where cyclists, dog-walkers and runners alike traverse both sides of the creek, it’s not often one finds much litter.

West of Willowside Road however, paints a different story.

Here, where the path ends at the bank of the creek, broken branches intersperse with buried and hanging refuse.

Gatorade, mayonnaise and Fireball bottles, soccer and golf balls, Nerf bullets, ballpoint pens, hypodermic needles, nasal sprays—you name it and Carol Shumate, the clean team director at Russian Riverkeeper, has seen it. Not just here, but all over the county.

Shumate said the state of Willowside Creek is the result of garbage that has evaded trash and recycling bins.

“It comes from the gutters and the drains. The trash starts flowing, it rains a lot, it goes through the pipes, and then ends up here,” Shumate said.

Some of the trash is easy to spot, as it bobs along the creek’s water. Other pieces, however, sink to the bottom, making removal considerably more difficult.

The Santa Rosa Creek isn’t the only problem spot. In west Sonoma County, the banks of the Russian River are rife with plastic left behind at encampments. Behind the Safeway in Guerneville, for example, abandoned encampments were flooded this past winter. When flash flooding does occur, these encampments are submerged underwater, and whatever plastic that was left is easily swept into the river, Shumate says.

Guerneville is one of a handful of hot spots along the Russian River where Shumate and her team focus to collect trash. According to Russian Riverkeeper’s website, the Clean Camp Program assisted “between 120 to 125 unhoused individuals in the communities along the Russian River from Cloverdale to the coast in keeping their camps clean and free of trash.”

The focus is to keep trash and plastics out of the water. It doesn’t just make for an eyesore; the plastic is causing both local and global environmental damage. Over time, the polymers comprising plastic bottles degrade into smaller pieces, eventually becoming microplastics (pieces less than 5 millimeters) or nanoplastics (pieces between 1 nanometer and 1 micrometer).

The longer these polymers remain in nature, the longer they travel between ecosystems and food chains. Today, microplastics and nanoplastics are so prevalent that scientists know they’re in our food, air, soil and water. Microplastics have been sampled in salt from Bangladesh, India and Spain, sugar in Germany, tea bags in Canada, honey in Switzerland and seafood from around the globe, including, Australia, Malaysia, Egypt, China and South Korea.

The global plastic problem

Despite calls from environmentalists, legislators and scientists, plastic has become more prevalent, not less.

The amount of plastic produced globally doubled between 2000 and 2019 and is expected to triple by 2060. According to the National Institutes of Health, it is estimated that plastic materials comprise between 60 and 80 percent of the waste in marine environments and 90 percent of the garbage floating in seas and oceans.

In recent years, scientists around the world have begun to uncover the ways in which humans may be more susceptible to the negative health effects of plastic than what was previously understood.

Researchers have found micro and nanoplastics in the liver, spleen, heart, lungs, thymus, reproductive organs, kidneys and brain of animals. They’ve been found in the human body, too; from the bloodstream to vital organs to breast milk. In fact, data has shown that such additives can disrupt the human body’s basic functions, such as the endocrine and reproduction systems.

As for how this plastic can get inside the body in the first place, studies indicate that microplastics and nanoplastics shed from everyday bottles, including baby bottles and single-use plastic containers. Other recent studies have shown the polymers also shed from polyester clothing. Microplastics and nanoplastics make their way into food via farm soil and, of course, through contaminated food chains, particularly fish and crustaceans.

‘We simply do not know’

To combat the threat of microplastics and nanoplastics getting into community tap water, California is taking the problem head on. The state was the first in the country to adopt a plan to test drinking water supplies for microplastics.

Senate Bill No. 1422, enacted on Sept. 28, 2018, requires the California State Water Resources Control Board to “adopt a standard methodology to be used in the testing of drinking water for microplastics and requirements for four years of testing and reporting of microplastics in drinking water, including public disclosure of those results.”

The Southern California Coastal Water Research Project (SCCWRP) was tasked with developing a laboratory accreditation program for measuring microplastics, and for distributing methods and regulations to water suppliers across the state.

“California is leading the world in standardized testing for microplastics,” said Dr. Stephen Weisberg, executive director of SCCWRP.

SCCWRP’s identification of a sampling method and protocol for selected public water systems is still ongoing. Sonoma Water, the main water supplier for Sonoma County, will be among the first 30 or more California water suppliers to implement the standardized methods. Sonoma Water estimates that this sampling will begin in the fall of 2025, although that is subject to change.

“Sonoma Water staff will begin testing as soon as monitoring orders are issued from the State Water Resources Control Board,” Ellen Simm, water agency coordinator at Sonoma Water, said in an email. “We take our responsibility for providing the community with reliable drinking water very seriously.”

But, Simm noted that without testing, the water agency can’t rule out the presence of microplastics and nanoplastics.

“We simply do not know,” Simms said in an email.

Sonoma Water receives its supply from Lake Sonoma, and to a lesser extent Lake Mendocino and Lake Pillsbury, where reservoir water is directed toward the Russian River. In the Mirabel area near Forestville, an inflatable dam supports six groundwater wells during peak months. The wells pump the water down to around 100 feet below the riverbed, with the sand and gravel serving as a natural filter.

This naturally-filtered water is delivered through an aqueduct system to Windsor, Santa Rosa, Rohnert Park, Cotati, Petaluma, Novato, Valley of the Moon and Sonoma.

Steven Lee, Senior Scientist and Research Program Manager at Sonoma Ecology Center, suspects that out of the many municipalities in the state, Sonoma County is well suited to combat the problem of MNPs in its drinking water.

“When you extract groundwater, you do not have to worry as much about foreign particles because these are filtered out as the water percolates down through the soil layers,” Lee said.

While the county’s underground riverbed would likely combat microplastics or larger nanoplastics, there is still concern that polymers can get so small that they could conceivably make it through the natural filter.

“Once plastic makes it down to the nanometer scale, traditional filtration becomes much more difficult,” Lee said.

Residents concerned about possible polymers in the drinking water can purchase at-home reverse osmosis filtration systems such as those made by Brita or Vitev.

Local effort to study plastics

Local scientists have also taken it upon themselves to test Sonoma County’s water and shores for plastic contamination.

In 2022, Dr. Manza Atkinson at Sonoma State University (SSU), along with his student Cesar Torres, collected debris that appeared synthetic or unnatural on the shore of Driftwood Beach, where the Russian River meets the Pacific Ocean.

Atkinson and Torres used Fourier Transform Infrared Spectroscopy (FTIR), one of two methods likely to be implemented by the California State Water Resources Control Board for water supplier testing, to identify the nature of each polymer. The duo found an abundance of polystyrene, a synthetic polymer used in styrofoam.

Atkinson and Torres have also taken plankton net samples out of Dry Creek, one of the principal tributaries of the Russian River. Their initial imaging suggests the possibility that polymers smaller than the size of plankton may be in their sample, but they cannot say this with confidence.

Putting preventative measures in place

Two years after Atkinson’s initial research, polystyrene still litters Driftwood Beach.

“Look at that piece of styrofoam from shipping,” Shumate said during a recent Russian Riverkeeper cleanup event. “How did it end up here? It should not be here. It is just going to break apart into more and more tiny pieces. All these white dots are just this stuff broken down.”

Styrofoam is notorious for its inability to recycle and for its fragility. To combat this, between 2018 and 2022, jurisdictions in Sonoma County adopted ordinances that effectively banned the sale and use of single-use products made with polystyrene foam.

The overall effectiveness of this ordinance is unclear, though Sloane Pagal, the Zero Waste program manager at Zero Waste Sonoma, says the efforts of her team and locals have persuaded a number of local businesses to get rid of polystyrene materials in the last couple of years.

“We have responded to many complaints regarding grocery stores and restaurants, who have since come into compliance by transitioning to alternative products,” Pagal said. “As a coastal community, it is important to target this ubiquitous packaging material to reduce its impact on ecosystems.”

As for Atkinson and Torres, they claim their research requires more funding from the community and the university to effectively make a declaration about their sample. They encourage residents to support their research on SSU’s Annual Giving Day on April 4.

“We want Sonoma County to know the state of things, and we want to show people where we stand as chemists,” Atkinson said. “We all love this place. If we keep up some of these habits, a lot of it will not be around anymore.”