The Sierra Fund Presents

Reclaiming the Sierra 2019: Mercury in the Headwaters Tour

Friday, October 18 A day-long excursion to explore headwater sources of mercury and discuss opportunities to restore ecosystem and community resiliency in the Yuba and Bear River watersheds. 9:00 am- 5:00 pm

Tour Agenda

Time Location

8:30-9:00 am Meet at Gold Miner’s Inn- Load into Buses and Vans

9:30-11:15 am STOP 1: Englebright Dam Speaker: Carrie Monohan, Ph.D., The Sierra Fund, Hydraulic Mine Features: Debris Control Dams

11:30 am- 12:00 pm STOP 2: Blue Point Speakers: Brian Bisnett, Blue Point Partners, Blue Point Mine: Past, Present, and Future Elizabeth “Izzy” Martin, The Sierra Fund, Due Diligence on Mine-Scarred Lands

12:30-1:30 pm Sycamore Ranch Lunch and Networking

1:30-2:30 pm Hammon Grove Park Speakers: Alexandria Keeble-Toll, M.A., M.Sc., The Sierra Fund, Mercury-Contaminated Fish Carrie Monohan, Ph.D., The Sierra Fund, Yuba Goldfields: Hydraulic Mine Debris: Barriers and Opportunities

Bonus Tour 3:00-5:00 pm Combie Reservoir Speakers: Carrie Monohan, Ph.D., The Sierra Fund, Hydraulic Mines and Reservoir Sedimentation Greg Jones, Irrigation District, Reservoir Maintenance: Removal of Mercury-Contaminated Sediment Nick Graham, M.S., The Sierra Fund, Combie Reservoir Monitoring Plan Englebright Dam

Hydraulic Mine Features: Debris Control Dams

Sawyer Decision: Northern was the birthplace of hydraulic gold mining in 1853. In the subsequent 30 years a altered the remarkable amount (>one billion cubic meters) of hydraulic mining sediment was generated in the northern . topography of Downstream valley farmland of the Sacramento region was repeatedly flooded and destroyed by mining debris. In response to the Sierra Nevada this, residents of Marysville formed the “Anti-Debris Association” headwaters. and implored the State Legislature to regulate mining operations. In 1882 Marysville property owner Edward Woodruff filed suit against Powerful water the North Bloomfield Mining and Gravel Company, which among other mines operated the hydraulic mine Malakoff Diggins. Hydraulic cannons washed mining was “banned” in 1884 after the California courts heard the away mountaintops Woodruff v. North Bloomfield Mining and Gravel Company case and Judge Lorenzo Sawyer ruled in favor of Woodruff. This action, which and cut into became known as the “Sawyer Decision,” is widely acknowledged as hillsides, and much California’s first environmental law. of this material Hydraulic mining recommenced after Congress passed the Caminetti Act of 1893 and continued until 1950. The Caminetti remains in the Act permitted hydraulic mining to occur as long as sediments were headwaters today. captured and not allowed to reach “navigable waters.” This resulted in numerous Debris Control Dams (DCDs) of varying size and type (log cribs, rammed earth and concrete) being built across the headwaters. The California Debris Commission (CDC) identified four locations for large debris control dams on rivers, of which two were constructed: North Fork Dam on the North Fork of the American River and Englebright Dam on the South .

DCDs have long outlived their purpose, but continue to interrupt longitudinal connectivity of habitat, and sediment and nutrient regimes in the watersheds. These man-made structures continue to accumulate hydraulic mine debris and represent a unique opportunity to remove mercury-contaminated sediment from the aquatic environment. Englebright Dam: Englebright Dam, a 260 ft. high concrete barrier, was constructed in 1941 by the CDC for the specific purpose of holding back debris generated by hydraulic mining. Englebright serves as the afterbay for New Bullards Reservoir hydropower facilities but does not provide any additional benefits, such as water delivery, power generation, or flood control. With a holding capacity of 70,000 acre feet of water, since its construction, Englebright Dam has trapped ~23,000,000 cubic yards of mercury-contaminated sediment, or roughly 25% of its original storage capacity. The dam represents the upstream limit of anadromous fish passage for Spring-run and Fall-run Chinook.

Opportunities for Recovery: Removal of mercury-contaminated sediment followed by removal or modification of Englebright Dam would open up a minimum of 60 additional miles of previously unreachable habitat for anadromous fish. Additional benefits of dam removal include restored natural flow, sediment, and nutrient regimes, reduced mercury methylation potential in the reservoir, and ultimately reduced mercury exposure risk for those who consume locally caught fish. The Sierra Fund is investigating previously unexplored options of sediment removal techniques for the accumulated hydraulic mine debris behind Englebright and the potential for multiple benefits, including sellable aggregates.

Next Steps: Mercury and sediment removal may make it feasible to restore longitudinal and lateral connectivity in the Yuba River if it allows for dam removal options or modification. TSF worked with Great Lakes Dredging Company to develop a preliminary feasibility study for sediment removal from Englebright. Specifically, we looked at the opportunity to remove 17M yd3 of sediment using a dredge. This is the volume of sediment that would need to be removed to allow for Englebright Dam to be lowered for a fish ladder. TSF is also working with Dennis Gathard of Gathard Engineering Consulting who wrote the preliminary feasibility study for Yuba River Fish Passage Improvement Investigation for National Marine Fisheries Service in April 2014 to determine why the opportunity for modification or removal of Englebright was not pursued. In 2014 dam modification, or lowering, to allow for volitional fish passage was estimated to cost between 60-64 million dollars. Blue Point Mine Past, Present, and Future

Hydraulic Mining: Over the period of 1853 to 1893, gold mining rapidly changed from consisting of individual miners using pans-and-hands to industrialized mining. In their fervent quest to find gold, miners developed some of the most innovative engineering feats of their time to aid in the process.

Hydraulic mining altered the topography of the Sierra Nevada headwaters as powerful water cannons (hydraulic monitors) were used to wash away mountaintops and cut into hillsides in search of gold-bearing gravels deposited in ancient river beds. Hydraulic mining was very successful in the Sierra because abundant surface water was available. By 1865, miners had constructed an estimated 5,000 miles of flumes, ditches, and canals to convey water to mine sites across the western slope of the Sierra.

Historically, material “power washed” from the hillsides was directed through sluice ditches and tunnels. Often, miners added mercury to the material washing through these sluice ditches and tunnels to facilitate gold recovery, subsequently discharging mercury-contaminated sediments to adjacent waterways. Blue Point Mine Past: This was once the site of the Gold- Rush era town of Sucker Flat – and of the Blue Point and Blue Gravel Mines, two of the richest hydraulic mines in California. The water for the operation came from Nevada City and Grass Valley in the Excelsior and China Ditches. The hydraulic slurry was carried out in long sluice tunnels carved at great expense through hard basaltic rock. The 2/3-mile long Excelsior Tunnel was built by crews working from either end and at a mid-point air shaft. The tunnel was lined with chunks of wood and mercury was distributed throughout to capture gold as the slurry passed through.

By 1877 a reported $13 million in gold had been mined from Blue Point, but the vast amounts of rock and gravel washed into the river caused tremendous destruction downstream. In 1884, the Sawyer Decision, supported by the valley’s farmers, stopped the thriving industry in its tracks.

Blue Point Mine Present: Left alone and all but forgotten for over a century, the property has largely revegetated itself. The town of Sucker Flat has vanished, and is occupied only by the cows which graze its grasses. The unique geology remains exposed on the cliff walls, where the Smartsville intrusive complex, a Jurassic volcanic and plutonic arc, is one of the only known locations on earth where basalt is seen on the surface of the geologic profile. In 2008 a reclamation project combined recycled green waste and mine tailings to create topsoil, which was spread across the valley floor and seeded, and the following spring the wildflowers returned.

Blue Point Mine Future: The Excelsior Foundation has a vision for Blue Point – that its 505 acres of natural and historic resources, its ditches and trails, its escarpments and Yuba river access, be permanently protected and made available to the public, creating a total of over twelve hundred acres of conserved area stretching from Smartsville to the Yuba River and from Timbuctoo to Mooney Flat Road. Blue Point Mine Due Diligence on Mine-Scarred Lands

In California’s Abandoned Mine Features: There are thousands of abandoned mine lands (AMLs) in California, many of which , have both physical and chemical hazards associated with them. public funds Abandoned hydraulic mines and mine features are sources of have been used to mercury-contaminated sediment to downstream watersheds. acquire mining- impacted lands for conservation and Legacy mine site characteristics may include: recreation without recognizing • Active Erosional Areas the physical and • Drain Tunnels chemical hazards • Shafts • Ditches associated with the • Ponds and Pits land’s historical • Gullies and Headcuts use. • Multiple Outflow Points Key Considerations:

• There are over 47,000 abandoned mine land features in California

• Chemical hazards include exposure to dust laden with heavy metals

• Physical hazards include shafts and pits, unstable slopes, and ongoing erosion

Due Diligence Protocols: The Sierra Nevada is riddled with abandoned mines and mine features that need to be assessed for chemical and physical hazards in advance of changes in ownership. In California’s Gold Country, governments and nonprofits alike have used public funds to acquire mining-impacted lands for conservation and recreation without recognizing the physical and chemical hazards associated with the land’s historical use. Over the last several years The Sierra Fund’s (TSF) Due Diligence on Mine-Scarred Lands Project has worked to establish protocols for appropriate due diligence prior to acquiring mine-scarred lands using public funds.

TSF is creating an assessment protocol to outline best practices for appropriate due diligence prior to acquiring mine-scarred lands using public funds. TSF’s assessment protocols outline best practices for mine-scarred lands that limit landowner liability and protect public health and safety. Key findings include: (1) the assessment, which includes discovery of physical or chemical hazards, should inform the appraisal value; and (2) when purchased by a governmental of non-profit agency, the purchase agreement should minimize the liability of the new owner for existing toxic materials on the site.

Next Steps: TSF continues to raise awareness about the importance of due diligence assessment in the Gold Country and to inform key state and local decision makers. The goal is to educate government agencies that fund land acquisition projects; inform agencies seeking funding for acquisition projects; minimize the liability of agencies purchasing land for conservation; restore habitat; and promote safe recreation for the public accessing these lands post- acquisition. TSF supports acquisition of mine-scarred lands as one strategy for remediating dangerous legacy mine features. Hammon Grove Park Mercury-Contaminated Fish

Background: Mercury was brought to the Sierra Nevada from the Coast Range and was used to recover gold during the 19th Century Gold Rush. Legacy gold mines dumped millions of cubic yards of mercury-contaminated mine waste into rivers including the Yuba. The United States Geological Survey estimates that at least 10 million pounds of mercury was lost to the environment from gold mining. This toxic metal has worked its way down from hydraulic mines in the headwaters and accumulated in reservoirs and in the Bay-Delta.

Bioavailable Mercury: Elemental inorganic mercury that was used in gold processing is not nearly as problematic as mercury in a methylated form, which is bioavailable. In oxygen depleted water, elemental mercury can be transformed into methylmercury by sulphur and iron reducing bacteria. Methylmercury can be incorporated into the food web, both biomagnifying at each increase in trophic level and bioaccumulating in the tissue of aquatic organisms such as fish. Fish species that are both long-lived and predatory, such as black bass, are typically associated with higher levels of mercury than species that are lower in trophic position, such as rainbow trout.

Human Exposure to Mercury: The primary pathway of human exposure to mercury is through the consumption of contaminated fish. The human health impacts of mercury are numerous and well-documented. Effects can include damage to the brain, nervous system, kidneys, and immune system. Exposure is especially dangerous for pregnant women because methylmercury easily passes through the placental and blood-brain barrier. Methylmercury is also problematic for children since their nervous systems are still developing. Both of these groups are vulnerable to even low levels of exposure to methylmercury from fish consumption. Other at-risk populations include groups for whom fish is a dietary staple, such as native groups, low-income populations, and ethnic minorities who have a culture of fish consumption and may be prevented from understanding fish advisories due to language barriers, as well as avid anglers who fish and consume their catch with relative frequency. Mercury Fate and Transport- From Mines to Methylation:

• Mercury is primarily transported bound to particulate fine silts and clays (< 0.063 mm) during winter storms.

• Mercury can be transported long distances from source areas and can accumulate in reservoirs where the water velocity slows and transport capacity decreases.

• Mercury methylation typically occurs most efficiently during warm summer months in anoxic zones that establish at the bottoms of reservoirs

• Mercury can be methylated when sulfate- reducing and/or iron-reducing bacteria are allowed to develop in anoxic conditions.

• The primary exposure pathway to mercury is through fish consumption

Fish Consumption Advisories: The California Office of Environmental Health Hazard Assessment (OEHHA) develops and issues fish consumption advisories, outlining how many servings per week different species of fish can be safely consumed, based on mercury levels in fish tissue. These advisories are often site-specific, which means that the advisory reflects fish data collected specifically in that water body. For other water bodies where there is insufficient site-specific data, Statewide Advisories, including those for lakes and reservoirs, coastal locations, and fish that migrate provide healthy eating guidelines for various commonly consumed species. Fish consumption advisories for water bodies in the state of California can be accessed at OEHHA’s website: www.oehha.ca.gov/fish Hammon Grove Park Yuba Goldfields

The Lower Yuba River, Pre-Gold Rush: This area is The Yuba within the historic floodplain of the Yuba River. Prior to the Gold Goldfields Rush, the floodplain was up to two miles wide, and comprised of wetlands, multiple channels, and riparian forests. The Lower Yuba comprises a River was a popular salmon harvesting location for the Nisenan Indians who inhabited this part of California for thousands of nearly 10,000- years before European contact. acre area that Early Gold Mining: Gold was discovered in the Yuba River is visible from within one month of the famous discovery at Sutter’s Fort. Gold outer space. mining towns like Parks Bar, Sand Flat, Sucker Flat, and Yuba Dam sprang up seemingly overnight. Thousands of mules pulling wagons from Marysville made daily trips on the river road on the south side of the Yuba.

Hydraulic Mining: Hydraulic mining forever changed the Yuba. As the “water cannons” (hydraulic monitors) literally washed away entire sides of mountains, debris was sent downstream, choking the river with sediment, boulders, rocks, gravel, and sand. Between 1859-1909, nearly 700 million cubic yards of material washed down the Yuba River – approximately 44% of the total debris produced by hydraulic mining on all Sierra Nevada streams.

The debris filled canyons in the headwaters and below Parks Bar, where the river enters the historic floodplain, debris spread out at an average depth of over 40 feet.

Impacts: Hydraulic mining debris drastically altered floodplain function on the Lower Yuba. The river changed course through the debris during high flows and frequently flooded. The California Debris Commission (CDC) was established to engineer remedies to the issues posed by hydraulic mining debris. Dredge Mining: The hydraulic mining debris that settled on the Yuba River floodplain was rich in gold because the gold extraction techniques used in the mountains were inefficient. Large-scale dredge mining to recover gold in the lower Yuba commenced in 1905. George Hammond pioneered the construction of the massive dredges and eventually the Yuba Dredge Company in Marysville. As many as 27 dredges, all greater than 100 feet in length, could be working at the same time, creating massive piles of tailings and inundating swales and ponds.

Controlling the River: The CDC worked in coordination with the dredgers to manipulate the Yuba into a preferred channel to prevent downstream flooding. The CDC built three low-head dams, including Daguerre Point Dam, which was placed north of the historic Yuba River channel. The dredgers worked in concert to create tall piles of material (dredge tailings) that constricted the river to flow to the desired path. These piles, which still comprise much of the river bank for the 10-mile length of the Goldfields, were dubbed “training walls” for their purpose in controlling the river.

An Opportunity to Restore Resiliency: 74% California’s native salmon, steelhead and trout are threatened by extinction. The best opportunity for recovery of Central- Valley Spring-run Chinook exists on the Yuba River. Today the Yuba Goldfields present a multi-benefit opportunity to address legacy mining impacts and restore ecosystem resiliency. The dredge tailings are a sellable aggregate, and by removing them to de-channelize the river it may be possible to simultaneously address mercury-contaminated fine sediment entrained in the gravel, increase floodplain connectivity and restore spawning and rearing habitat for anadromous fish. Bear River

Reservoir Sedimentation

Site Summary: During the , mercury was used in mining operations to aid in gold recovery. Today, storm events wash sediment and mercury from contaminated legacy hydraulic mine sites into creeks and rivers. This material flows downstream and accumulates in reservoirs, where sediment reduces water storage capacity and elemental mercury methylates and enters the food web, bioaccumulating and biomagnifying in fish. Fish consumption is the primary pathway of human exposure to mercury which is a known neurotoxin.

Background: Numerous legacy hydraulic mines exist in the Bear River watershed and as a result the watershed is significantly impacted by sediment and mercury. Nevada Irrigation District (NID) owns and operates two reservoirs on the Bear River which are listed under Clean Water Act section 303(d) as impaired for mercury: Rollins Reservoir and Combie Reservoir.

Reservoirs impound winter precipitation and Sierra snowmelt for use in agriculture, irrigation, drinking water, hydropower and recreational activities. Over the decades, upper watershed erosion and downstream sedimentation have influenced NID efforts in maintaining reservoir storage capacity, potentially affecting NID’s operational activities. Notable Features: Sediment & Mercury Removal Projects:

• Combie Reservoir Reservoir maintenance includes sediment removal to maintain water storage space and operational originally stored capacity. Sediment carried in the Bear River contains approximately 5,500 acre- mercury that originates from historical gold mining performed in the Bear River watershed over a feet of water fed by the century ago. The presence of mercury has previously Bear River and Wooley precluded reservoir maintenance dredging activities as it stirred-up and distributed mercury within the Creek. Sedimentation has sediment. Removal of sediment in the dry, when reduced the lake’s volume the reservoir is low, is the most economical way to to approximately 3,500 Acre- maintain reservoir capacity, however, some deposits cannot be accessed in this way. feet. To address sediment removal in wet conditions, an innovative approach is being developed, whereby • Rollins Reservoir sediment is removed using a suction dredge and originally stored 66,000 the sediment “slurry” is treated offshore to remove acre-feet of water fed mercury before clean water is returned to the reservoir. Due to the presence of mercury, reservoir by Greenhorn Creek and sediment removal projects need to integrate Steephollow Creek and has technical expertise and environmental monitoring. These projects have great potential to model ways lost approximately 20% of to restore water storage capacity throughout Sierra- its water storage capacity. based reservoirs, while remediating mercury left in watersheds from legacy mining. Sediment and Mercury Removal

Combie Reservoir

Site Summary: For more than 30 years, Nevada Irrigation District (NID) contracted with private aggregate mining companies to remove sediment that accumulates in the reservoir. At Combie Reservoir, dredging was used to remove sediment. Dredging operations in Combie Reservoir were halted in 2003 as a result of mercury levels found in dredge effluents, affecting NID’s efforts to maintain reservoir storage capacity and operations.

Because of mercury contamination, there is a need to develop an innovative approach to sediment removal from reservoirs impacted by mercury. NID’s Combie Reservoir Sediment and Mercury Removal Project is a three step process: (1) sediment removal, (2) sediment treatment, and (3) water treatment.

1) At Combie Reservoir, sediment removal can be done in the dry or in the wet. In the dry, earth moving equipment is used to remove accumulated sediments during low water conditions when the deposit is exposed. In the wet, a suction dredge is used to suck up material from the bottom of the reservoir and transport that material in a slurry to a treatment plant on the shore. 2) The sediment is treated using a centrifuge to remove elemental (“free liquid”) mercury. 3) The slurry water is then treated by using a combination of coagulants and polymers to settle out the fines and return clean water to the reservoir.

NID began removal of accumulated sediment in 2018 under a Department of Water Resources grant, using both removal in the dry and removal in the wet methods. On-going reservoir maintenance of sediment removal is needed to maintain reservoir capacity. The project is operating under a water quality permit that requires monitoring to ensure that no water quality standards are being violated at any time in the process.

Conclusion: NID’s pilot project demonstrates emerging technology and improved understanding of mercury that will inform sediment removal efforts in other locations where mercury-contaminated sediment accumulates. In time, a reduction of mercury contamination in reservoirs will benefit streams and rivers in the headwaters all of the way to the -Delta.

Permitting Agencies CA Department of Fish & Wildlife US Army Corps of Engineers CA Central Valley Regional Water Quality Control Board Project Funding Department of Water Resources Sediment & Mercury Removal at Combie Reservoir

1. Sediment Removal- Dry and Wet

2. Sediment Treatment 3. Water Treatment

Mechanical Mercury Extraction Slurry Polymer Injection Station

Clean Water Returned to Bear River Settling Tanks or Ponds Monitoring Plan

Combie Reservoir

Summary: To evaluate the effect of excavating mercury- contaminated sediment from Combie Reservoir and processing it, a four-part monitoring plan was developed that includes:

1. Regulatory compliance monitoring being conducted by NV5 and Nevada Irrigation District (NID) 2. Effectiveness Monitoring being conducted by NV5, NID, and Great Lakes Environmental and Construction 3. Reservoir Ecosystem Monitoring being conducted by United States Geological Survey (USGS) 4. Real-Time Monitoring being conducted by The Sierra Fund (TSF)

This work is partially funded by the Department of Water Resources and is key to developing best-practices that can be scaled up and replicated. The results of the monitoring efforts will enable a thorough evaluation of the project, lessons learned and tools that can be applied to other sediment and mercury removal projects.

Evaluating the methods proposed in this project and documenting its outcome provides a path to clean up other similarly contaminated sediments in mining- impacted Sierra Nevada watersheds and elsewhere, and to reduce the threat of mercury exposure across California. The project will serve as a reference to managers, engineers, scientists and regulators involved with maintenance dredging and mercury source reduction. Monitoring Components:

1. Regulatory Compliance: The water quality permits require that a suite of parameters that might be effected by the process be evaluated prior to the start of the project. The Anti-Degradation Report identifies the constituents that need to be monitored during the project. The Clean Water Act Section 401 certification specifies the frequency that these parameters need to be monitored to ensure that the project is within all water quality regulations during operation.

2. Project Effectiveness: The amount of sediment that is treated and the amount of mercury removed from the treatment process is being evaluated throughout the process. Liquid elemental mercury and the particulate-bound mercury associated with the fines are being removed by this process. Liquid elemental mercury is removed by the centrifuge and particulate-bound mercury is removed with the coagulants and polymers. The effectiveness of sediment and water treatment steps will be monitored so that an adaptive management approach can be used to improve the engineering processes throughout the project.

3. Reservoir Ecosystems: The ecosystem monitoring is being conducted before, during and after the project to see if by removing mercury- contaminated sediment there is a measurable effect on the aquatic food web. Simply put, “are the fish less contaminated?” The dynamic processes in the food web means that many different steps are monitored to be able to detect a difference including: five size classes of phytoplankton, young-of-the-year-fish, and methylmercury in the water near the bottom of the reservoir (benthic exchange).

4. Real-Time Model: Real-time monitoring is being used to predict mercury levels in the water based on a suite of parameters that can be monitored continuously. The multivariate predictive model is being developed using parameters that are known to have associations with mercury concentrations including: total suspended solids, total dissolved solids, turbidity, and fluorescence of dissolved organic matter. Real time monitoring enables the project to adaptively manage the removal process if an issue were to ever arise.