Tackling Pollution

Tackling Pollution

Though the Clean Water Act did an amazing job of reducing wastewater and stormwater pollution of the San Francisco Estuary, some contaminants remain thorny problems.  Legacy pollutants like mercury washed into the watershed from upstream gold mining, PCBs from old industrial sites, and selenium from agricultural drainage in the San Joaquin Valley, linger in the sediments, nearly impossible to clean up.  Emerging contaminants from contemporary lifestyles such as herbicides, flame retardants, and fire-fighting foams are being linked to human health problems, while microplastics are turning up everywhere from fish guts to creek bottoms to newborns. More recently, nutrients from both farm and sewage discharges have become a particular challenge for the Estuary. Long protected by its sediment-clouded waters, a recent clearing is spurring algal blooms, some harmful. Now sea level and groundwater rise threaten to mobilize long-buried toxics around the Bayshore.  

Recurring topics in our Estuary News stories include plastics, mercury, emerging contaminants (PBDE, PFOS, BPA, etc), fish consumption, and the findings of the Bay’s Regional Monitoring Program (RMP).  Coverage also explored what to do about polluted runoff (see Greening Stormwater).

Editor’s Picks

  • Bay Fish Still Not Good Eating
    Bay Fish Still Not Good Eating

    After decades of efforts to clean up San Francisco Bay, its fish still carry a toxic load that makes them unfit for human consumption. A new Regional Monitoring Program (RMP) report on its 2019 sport fish survey contains some positive news: an overall decline in polybrominated diphenyl ethers (PBDE), hopeful trends in polychlorinated biphenyls (PCBs) […]

  • Bay Oil Spills: Never Again, and Again
    Bay Oil Spills: Never Again, and Again

    Oil spills in San Francisco Bay are frequent news, but for those old enough to remember there is only one Great Oil Spill, the disaster of January 18, 1971. In a predawn darkness thickened by heavy fog, two small Chevron tankers were maneuvering through the strait. At San Francisco’s Pier 45, Coast Guard technicians were […]

  • The Delta’s Blooming Problem
    The Delta’s Blooming Problem

    Bright-green blotches of algae have been popping up all over the Delta since early summer, from Discovery Bay to the Stockton waterfront, befouling the air and poisoning the water with toxins that can sicken or even kill humans and animals. Veteran Delta watchers believe that this year’s harmful algal blooms may be the worst ever, […]

  • Kinky Fish Spines Linked to Selenium
    Kinky Fish Spines Linked to Selenium

    Scientists with the U.S. Geological Survey and the National Oceanic and Atmospheric Administration are using new tools to track selenium, with the Sacramento splittail, a California-endemic fish, as an indicator species. In some sampled splittail, selenium levels exceeded the proposed EPA protective criteria for fish ovaries.

  • Non-Sticks Stick Around
    Non-Sticks Stick Around

    Common coatings and repellants used in textiles for clothing and furniture are sticking around in San Francisco Bay. “The reason for the lack of declines is not clear,” says researcher Meg Sedlak of the San Francisco Estuary Institute. Some early environmental offenders in this line of fluorinated chemicals (PFASs) have been banned, including one used in Teflon. “In 2006 and 2009, the levels of some PFAS we found in Bay cormorant eggs were among the highest observed concentrations in the world,” says Sedlak.

  • Freeing Fish While Locking Up Mercury
    Freeing Fish While Locking Up Mercury

    Restoration planners were worried that connecting a former salt evaporation pond with the Bay could introduce long-dormant mercury to the wider ecosystem, and initial studies of levels in water bird eggs and fish reinforced that concern. A set of adjustable gates between the pond and the river allows seasonal closure of the pond and the ability to control the flow. But that raised a new question: would the river’s steelhead run get sidetracked…

  • Bay Primed for Pea Soup?
    Bay Primed for Pea Soup?

    Nutrients could be the next big problem for San Francisco Bay — or make that in the Bay, because they’re already here at levels high enough to have caused trouble elsewhere. But despite its excess nitrogen and phosphorus, the Bay has been free of harmful algal blooms and oxygen-depleted dead zones for decades. Indeed, we’ve been so sure of this immunity to nutrients that most wastewater treatment plants don’t even have to remove them before discharging into the Bay. Recent chinks in the Bay’s resistance to nutrients are now alerting us, however, to get ready in case there’s worse to come.

Further Selections

  • Science in Short: The Hullabaloo About HABS
    Science in Short: The Hullabaloo About HABS

    Dead fish belly up in Lake Merritt and San Francisco Bay this past August sent scientists like Keith Bouma-Gregson scrambling to pinpoint the cause. A harmful bloom of marine algae had taken up residence in the Bay. Bouma-Gregson discusses his observations of the event in this podcast.

  • Habitat Tramplers Run Amuck – Cows Versus Creeks
    Habitat Tramplers Run Amuck – Cows Versus Creeks

    The water of a small stream in western Sonoma County flows slowly under a highway bridge, coursing its way through private ranchland to the ocean about seven miles away. Ducks paddle among floating vegetation, and an egret tiptoes slowly through the shallows. At the edge of the waterway, called Americano Creek, a cluster of cattle […]

  • Nudging Natural Magic
    Nudging Natural Magic

    “Miraculous” isn’t a term that comes easily to the lips of scientists and engineers. But the word cropped up more than once in interviews concerning the results of the horizontal levee experiment on the San Lorenzo shore – including off the charts levels of removal of nitrogen and pharmaceuticals from wastewater passed through the system.

  • An Eggfull of Estuary
    An Eggfull of Estuary

    Birds’ eggs don’t lie. Just as thinning eggshells once revealed how DDT was affecting peregrines and pelicans, the eggs themselves are now telling scientists how long-lived some contaminants are in the Estuary and where they are the most problematic.

  • Unhealthy Fiber in Bay Diet
    Unhealthy Fiber in Bay Diet

    Millions of tiny pieces of plastic, each less than five millimeters wide, are flowing into San Francisco Bay each day. This minute debris—known as microplastic—is a growing environmental concern for water bodies worldwide as it evades filtration and mimics food consumed by wildlife. A recent study…

  • Editor’s Pick Pollution Stories 1993-2013
    Editor’s Pick Pollution Stories 1993-2013

    Walk back through time with this selection of early stories from Estuary’s first two decades of publication. Stories covered oil spills, fish kills, and alarm bells over pesticides, runoff and hot spots, as well as early efforts to curb contaminants and monitor discharges to estuary waterways.

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