The Guadalupe River watershed is located just south of the San Francisco South Bay and begins in the eastern Santa Cruz Mountains. This historically rich watershed is one of seven anchor watersheds in the San Fancisco Bay and is home to the New Almaden Mining District, one of the largest historical mercury mines in the world. We work with local partners to remediate this watershed and reduce mercury pollution.
The Guadalupe River watershed is located just south of the San Francisco South Bay and extends to Loma Prieta, draining 171.3 square miles with a maximum elevation of 3,790 feet. The headwaters of the Guadalupe River watershed begin in the eastern Santa Cruz Mountains and flow 19 miles north, through lakes and reservoirs, to the Guadalupe River and out the Alviso Slough, passing eight salt pond restoration sites before emptying into the South Bay. This historically rich watershed is one of seven anchor watersheds deemed of critical importance to restoring native steelhead (Oncorhynchus mykiss) populations. It is also, home to the New Almaden Mining District.
CCMP Goals and Actions
Goals Water Quality and Quantity
Actions Action 27
Mercury
The Problem
The Solution
Our Projects
Concentrations of methylmercury in phytoplankton are 100,000x the concentration in the surrounding water. Each link in the chain multiplies this by an additional 10x. In this diagram, sport fish could contain as much as 100,000,000 times the methylmercury found in the surrounding water.
Mercury persists in the environment and in the bodies of people and wildlife that come into contact with it. It is a potent neurotoxin and readily crosses the blood brain barrier causing a number of physical ailments. In the environment, mercury has various forms that are absorbed at different rates, methylmercury being the most bioavailable. Elemental mercury bound in sediments and ores are relatively innocuous until they find their way into low oxygen environments and are methylated. Such environments include wetlands, reservoirs, and lakes. Methylmercury “bioaccumulates” in the food web, meaning that large predator fish and fish-eating birds build up significant amounts of mercury in their bodies. Because of the amount of mercury still present in the Guadalupe River watershed, anglers and subsistence fishers are warned not to eat any fish caught in waters downstream of the mining district including Almaden, Guadalupe and Calero reservoirs, Lake Almaden, the Guadalupe River, and several creeks in the watershed. Mercury has been shown to reduce reproductive success of higher level predators. In addition, sport fish have become one of the largest vectors of mercury absorption in humans. In the South Bay, mercury is very prevalent due to the extensive mining operations in the New Almaden Mining District, located in Santa Clara County’s Guadalupe River watershed. Named after its Spanish predecessor, the mining district was the largest in the United States (5th largest in the world), producing almost 40% of the nation’s total.
The New Almaden Mining District, now largely located within Almaden Quicksilver County Park, operated from 1846 until 1975, when Santa Clara County bought the land. It was the largest mercury mine in North America and produced 5% of the world’s total mercury. The Guadalupe River watershed houses this old mining district and has been significantly impaired by its operations, resulting in a Mercury Total Maximum Daily Load (TMDL) that was finalized in 2008. A TMDL is a regulatory mechanism that puts limits on a given pollutant for a water body that has been listed as impaired by that pollutant. The Guadalupe River TMDL addresses several lakes and reservoirs. These listed water bodies have some of the highest fish methylmercury levels in California, and are posted with “do not eat the fish” signs, one of only two areas in California with “do not eat” fish consumption advisories as contrasted to “limited consumption” advisories.
Cinnabar
Mercury in the mining district is bound in a mineral called cinnabar. This reddish-pink rock is naturally occurring and relatively harmless when left alone. When this district was active, miners would excavate the cinnabar ore, roast it to vaporize the mercury, and then dispose of the leftover material. The leftover heat-processed wastes are referred to as calcines.
The rock behind the photo ruler is a large calcine deposit with hazardous concentrations of mercury.
The method of extraction described above, while effective in extracting mercury, was not perfect. The leftover calcine material still housed hazardous concentrations of mercury. These toxic calcines were commonly disposed of in headwaters high in the mountains where heavy winter storms would flush the material downstream. In other cases they were simply left in large unprotected piles. In this mining district, these calcines were also used to pave portions of the access roads, now trails throughout the park. These toxic materials have eroded into the watershed over time and have found their way into lakes, reservoirs, and other aquatic environments that can contain low oxygen levels. This is where the relatively harmless sediment-associated mercury is turned into a much more potent form. It is in these low oxygen environments where mercury is methylated by bacteria to form methylmercury. This very bioavailable form of mercury is readily dispersed throughout the water column and is absorbed by photosynthetic algae. Mercury concentrations in the algae are up to 100,000 times higher than that of the surrounding water. The animals that eat the algae are absorbing all of that methylmercury into their bodies and have even greater levels of methylmercury. Each step in the food chain increases the concentration of methylmercury by 2.5x, leaving the top predators like sport fish with hazardous levels in their tissues.
The first step in solving this mercury problem is to essentially turn off the tap, meaning we halt erosion of the mercury-laden sediments into aquatic environments. There are several ways to do this including soil stabilization, calcine removal and disposal, and capping. By doing this, we can keep the mercury from getting into environments where it can be methylated and enter the food web. Once all sources are controlled, measures to reduce methylation in reservoirs will need to be taken. The Santa Clara Valley Water district is currently testing the effectiveness of oxygen pumps in reservoirs.
The San Francisco Estuary Partnership has worked with many partners to help address the mercury problem in the Guadalupe River watershed and to implement its TMDL. These projects have been funded by several sources including the San Francisco Bay Water Quality Improvement Fund (EPA), and CWA 319(H) (State Water Resources Control Board), Mid-Peninsula Regional Open Space District and Santa Clara County. Our projects include: Hicks Flat – Complete Project ReportSenador Mine – Complete Project ReportCalcine Paved Roads – Complete Project Report, County Final Report, Avg Calcine Calculations, Site Visit Photos, 100% Construction Designs, County PresentationJacques Gulch – This project site was studied and feasibility report was created that detailed the options that could be pursued to remediate the reach. The report found that the cost, stability of the slopes, and large-scale landslides make the remediation of the site infeasible. See feasibility report and site study documents below: Feasibility ReportField Survey Documents
Nothing could be stranger than sitting in the dark with thousands of suits and heels, watching a parade of promises to decarbonize from companies and countries large and small, reeling from the beauties of big screen rainforests and indigenous necklaces, and getting all choked up.
It was day two of the September 2018 Global Climate Action Summit in San Francisco when I felt it.
At first I wondered if I was simply starstruck. Most of us labor away trying to fix one small corner of the planet or another without seeing the likes of Harrison Ford, Al Gore, Michael Bloomberg, Van Jones, Jerry Brown – or the ministers or mayors of dozens of cities and countries – in person, on stage and at times angry enough to spit. And between these luminaries a steady stream of CEOs, corporate sustainability officers, and pension fund managers promising percentages of renewables and profits in their portfolios dedicated to the climate cause by 2020-2050.
I tried to give every speaker my full attention: the young man of Vuntut Gwichin heritage from the edge of the Yukon’s Arctic National Wildlife Refuge who pleaded with us not to enter his sacred lands with our drills and dependencies; all the women – swathed in bright patterns and head-scarfs – who kept punching their hearts. “My uncle in Uganda would take 129 years to emit the same amount of carbon as an American would in one year,” said Oxfam’s Winnie Byanyima.
“Our janitors are shutting off the lights you leave on,” said Aida Cardenas, speaking about the frontline workers she trains, mostly immigrants, who are excited to be part of climate change solutions in their new country.
The men on the stage, strutting about in feathers and pinstripes, spoke of hopes and dreams, money and power. “The notion that you can either do good or do well is a myth we have to collectively bust,” said New Jersey Governor Phil Murphy whose state is investing heavily in offshore wind farms.
“Climate change isn’t just about risks, it’s about opportunities,” said Blackrock sustainable investment manager Brian Deese.
But it wasn’t all these fine speeches that started the butterflies. Halfway through the second day of testimonials, it was a slight white-haired woman wrapped in an azure pashmina that pricked my tears. One minute she was on the silver screen with Alec Baldwin and the next she taking a seat on stage. She talked about trees. How trees can solve 30% of our carbon reduction problem. How we have to stop whacking them back in the Amazon and start planting them everywhere else. I couldn’t help thinking of Dr. Suess and his truffala trees. Jane Goodall, over 80, is as fierce as my Lorax. Or my daughter’s Avatar.
Analyzing my take home feeling from the event I realized it wasn’t the usual fear – killer storms, tidal waves, no food for my kids to eat on a half-baked planet – nor a newfound sense of hope – I’ve always thought nature will get along just fine without us. What I felt was relief. People were actually doing something. Doing a lot. And there was so much more we could do.
As we all pumped fists in the dark, as the presentations went on and on and on because so many people and businesses and countries wanted to STEP UP, I realized how swayed I had let myself be by the doomsday news mill.
“We must be like the river, “ said a boy from Bangladesh named Risalat Khan, who had noticed our Sierra watersheds from the plane. “We must cut through the mountain of obstacles. Let’s be the river!”
Or as Harrison Ford less poetically put it: “Let’s turn off our phones and roll up our sleeves and kick this monster’s ass.”
4th California Climate Change Assessment Blues
by Isaac Pearlman
Since California’s last state-led climate change assessment in 2012, the Golden State has experienced a litany of natural disasters. This includes four years of severe drought from 2012 to 2016, an almost non-existent Sierra Nevada snowpack in 2014-2015 costing $2.1 billion in economic losses, widespread Bay Area flooding from winter 2017 storms, and extremely large and damaging wildfires culminating with this year’s Mendocino Complex fire achieving the dubious distinction of the largest in state history. California’s most recent climate assessment, released August 27th, predicts that for the state and the Bay Area, we can expect even more in the future.
The California state government first began assessing climate impacts formally in 2006, due to an executive order by Governor Schwarzenegger. California’s latest iteration and its fourth overall, includes a dizzying array of 44 technical reports; three topical studies on climate justice, tribal and indigenous communities, and the coast and ocean; as well as nine region-specific analyses.
The results are alarming for our state’s future: an estimated four to five feet of sea level rise and loss of one to two-thirds of Southern California beaches by 2100, a 50 percent increase in wildfires over 25,000 acres, stronger and longer heat waves, and infrastructure like airports, wastewater treatment plants, rail and roadways increasingly likely to suffer flooding.
For the first time, California’s latest assessment dives into climate consequences on a regional level. Academics representing nine California regions spearheaded research and summarized the best available science on the variable heat, rain, flooding and extreme event consequences for their areas. For example, the highest local rate of sea level rise in the state is at the rapidly subsiding Humboldt Bay. In San Diego county, the most biodiverse in all of California, preserving its many fragile and endangered species is an urgent priority. Francesca Hopkins from UC Riverside found that the highest rate of childhood asthma in the state isn’t an urban smog-filled city but in the Imperial Valley, where toxic dust from Salton Sea disaster chokes communities – and will only become worse as higher temperatures and less water due to climate change dry and brittle the area.
According to the Bay Area Regional Report, since 1950 the Bay Area has already increased in temperature by 1.7 degrees Fahrenheit and local sea level is eight inches higher than it was one hundred years ago. Future climate will render the Bay Area less suitable for our evergreen redwood and fir forests, and more favorable for tolerant chaparral shrub land. The region’s seven million people and $750 billion economy (almost one-third of California’s total) is predicted to be increasingly beset by more “boom and bust” irregular wet and very dry years, punctuated by increasingly intense and damaging storms.
Unsurprisingly, according to the report the Bay Area’s intensifying housing and equity problems have a multiplier affect with climate change. As Bay Area housing spreads further north, south, and inland the result is higher transportation and energy needs for those with the fewest resources available to afford them; and acute disparity in climate vulnerability across Bay Area communities and populations.
“All Californians will likely endure more illness and be at greater risk of early death because of climate change,” bluntly states the statewide summary brochure for California’s climate assessment. “[However] vulnerable populations that already experience the greatest adverse health impacts will be disproportionately affected.”
“We’re much better at being reactive to a disaster than planning ahead,” said UC Berkeley professor and contributing author David Ackerly at a California Adaptation Forum panel in Sacramento on August 27th. “And it is vulnerable communities that suffer from those disasters. How much human suffering has to happen before it triggers the next round of activity?”
The assessment’s data is publicly available online at “Cal-adapt,” where Californians can explore projected impacts for their neighborhoods, towns, and regions.