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Stormwater runoff is the rainwater that washes off landscapes, including cities, and flows towards water bodies. It\u2019s a major pathway for many contaminants to reach San Francisco Bay.\nSFEI\u2019s stormwater monitoring team has grown and is innovating techniques to further expand its sampling abilities.
\nSFEI\u2019s studies of microplastics<\/a>, forever chemicals, and other emerging contaminants have been influential in the Bay Area and globally.<\/p>\n
In January 2017, a steady downpour bathed San Jose for three days straight. While most of the city hunkered down, Alicia Gilbreath crouched on the banks of the Guadalupe River to collect water samples every four hours through the day and night.<\/p>\n
\u201cIt rose ten feet,\u201d she recalls. \u201cTo watch the vegetation and trash coming down, the change in the river\u2014that water is really powerful.\u201d<\/p>\n
Because Gilbreath was a whitewater rafting guide long ago, she appreciates the water\u2019s power. But for decades, she\u2019s been interested in the surges of stormwater for another reason: to track how contaminants arrive in San Francisco Bay, and to find where they come from.<\/p>\n
Gilbreath now leads SFEI\u2019s stormwater team. What began as efforts to study mercury and PCBs (banned industrial chemicals) has grown into a major branch of SFEI\u2019s Clean Water program and the Regional Monitoring Program for Water Quality in San Francisco Bay (RMP). The team now routinely breaks new scientific ground for the Bay Area\u2014and sometimes far beyond.<\/p>\n
\u201cThere\u2019s not a ton of literature on the concentrations of contaminants in stormwater collected during actual storm events, when the large majority of the pollutant load runs off from urban areas,\u201d says Gilbreath. \u201cSo we can\u2019t just draw on data from the rest of the world. We have to generate it to understand the pollutants that we\u2019re interested in.\u201d<\/p>\n
An Emerging Focus<\/p>\n
Two important Bay Area studies in the last decade heightened the focus on stormwater. In 2016, RMP scientists compared water samples from three distinct areas of San Francisco Bay: near a wastewater treatment plant, by the agriculture-influenced Napa River, and in San Leandro Bay, which receives runoff from Oakland and its surrounding highways. Laboratories scanned the samples for under-the-radar chemicals like less-studied pesticides, industrial chemicals, or plastic additives. The samples from San Leandro Bay \u201chad the most diverse contaminant signals and a lot of distinctive tire related chemicals,\u201d says Rebecca Sutton, the lead scientist for emerging contaminants at SFEI.<\/p>\n
\u201cIt really made us zero in on stormwater as something that the whole world needs to pay more attention to when it comes to emerging contaminants,\u201d she says.<\/p>\n
A few years later, the San Francisco Bay Microplastics Project revealed that trillions of microplastic particles reach the Bay each year via storm drains\u2014mostly in the form of car tire particles and synthetic fibers. The microplastics from stormwater dwarfed every other pathway studied. Other studies have since found that stormwater carries other contaminants, including PFAS and anti-microbial chemicals called QACs, at concerning levels.<\/p>\n
\u201cIt\u2019s all pretty groundbreaking stuff,\u201d says Chris Sommers, the program manager for the Santa Clara Valley Urban Runoff Pollution Prevention Program. \u201cIt\u2019s not something that a countywide stormwater program would necessarily take on by itself.\u201d<\/p>\n
Stormwater sampling for unregulated and less-monitored emerging contaminants has now blossomed into a major focus at the RMP, in part to fill gaps in basic knowledge. So far, SFEI\u2019s scientists have found significant amounts of forever chemicals, plastic additives, microplastics, car tire chemicals, pesticides, antimicrobial compounds, and many other contaminants in urban stormwater runoff. But because there\u2019s no easy for way know what chemicals many products in the built environment contain, finding the specific sources of these chemicals can be daunting.<\/p>\n
\u201cIt\u2019s a lot of detective work that\u2019s really quite tricky,\u201d says Sutton.<\/p>\n
Chemicals can also transform when exposed to sun, air, and water. Even when it\u2019s possible to determine which chemicals are in products used outdoors\u2014from cars to construction supplies\u2014they might not match the compounds scientists detect after leaching, weathering, or breaking off the original products and traveling through the environment.<\/p>\n
That\u2019s exactly how a team of scientists, including from SFEI, solved the mystery of coho salmon dying en masse in Washington. The chemical they identified, called 6PPDQ or \u201c6Q,\u201d was so toxic to coho that a few drops in an Olympic swimming pool would be fatal. It wasn\u2019t an ingredient sold on the market, but a transformation from another chemical in car tires.<\/p>\n
Storm By Storm<\/p>\n
Sleuthing for unknown chemicals isn\u2019t the only challenge stormwater scientists in the Bay Area face. Storms with adequate rainfall are rare enough that when they arrive, it\u2019s all hands on deck\u2014regardless of whether it\u2019s the middle of the night or holidays. Every drop of data is valuable.<\/p>\n
\u201cSuddenly it starts raining and you have to be out there soaking your butt off at like 1:00 a.m.,\u201d says Don Yee, who estimates he\u2019s spent 50 nights sampling stormwater over the last decade. \u201cIt\u2019s kind of fun the first few times, but somewhere into the fifth or sixth hour, you\u2019re saying, \u2018I can\u2019t wait to get home and take a nice warm shower.\u2019\u201d<\/p>\n
Gilbreath has been there too. \u201cIt\u2019s pretty labor intensive to monitor stormwater,\u201d she agrees. \u201cWe can\u2019t monitor everything.\u201d<\/p>\n
That\u2019s why the robots got involved.<\/p>\n
To be continued\u2026<\/p>\n
This article is part one of a special feature series on stormwater. Come back next month for part 2!<\/p>\n","protected":false},"excerpt":{"rendered":"Highlights Stormwater runoff is the rainwater that washes off landscapes, including cities, and flows towards water bodies. It\u2019s…\n","protected":false},"author":2,"featured_media":135024,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[30],"tags":[68927,184,68928,68929,68930,101,103,102,104,106,105,11564,68931],"class_list":["post-135023","post","type-post","status-publish","format-standard","has-post-thumbnail","category-san-francisco","tag-6ppd","tag-bay-area","tag-contaminants","tag-microplastics","tag-pcbs","tag-san-francisco","tag-san-francisco-headlines","tag-san-francisco-news","tag-sf","tag-sf-headlines","tag-sf-news","tag-stormwater","tag-tires"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/135023","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/comments?post=135023"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/posts\/135023\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media\/135024"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/media?parent=135023"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/categories?post=135023"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us-ca\/wp-json\/wp\/v2\/tags?post=135023"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}