III. Mercury TMDL Activities

Transcription

1 Delta Tributaries Mercury Council ~ Meeting Summary ~ Tuesday November 13, 2012; 12:30 p.m. 4:30 p.m. DWR; 3500 Industrial Blvd., West Sacramento, CA Facilitator: Stephen McCord, McCord Environmental, Inc. (MEI) Meeting Summary by: Holly Jorgensen, SRWP; Stephen McCord, MEI In Person Pete Halpin, Caltest Janis Cooke, RWQCB Hope Taylor, LWA Tim Stevens, CDFG Patrick Morris, RWQCB Lysa Voight, SRCSD Nan Bailey, SRCSD Bob Schneider, Tuleyome Tom Maurer, USFWS Janet Whitlock, USFWS Carol DiGiorgio, DWR Petra Lee, DWR Myint Thein, DWR Via Teleconference Tony Pirondini, City of Vacaville Josh Ackerman, USGS Holly Jorgensen, SRWP Leah Wills, Plumas Co. Elisa Sabatini,? Attendees Bryan Bemis, Applied Marine Sciences Fred Gius, DWR Flood Maint. Kathryn Gies, West Yost Assoc. Karen Jurist, USEPA Darell Slotton, UCD Frank Arriaza, BLM Ukiah Gary Sharpe, BLM Ukiah Amanda Palumbo, SWRCB Tim Vendlinski, USEPA Chris Foe, RWQCB Charlie Alpers, USGS John Henderson, USFWS Steve Blecker, Delta Science Program Debbie Webster, CVCWA Kat Garcia,? Barbara?,? I. Introductions and Agenda Review II. Project Updates & Upcoming Events Stephen McCord, MEI: Carol Atkins moderated a session on mercury studies at the Bay- Delta Science Conference. For more information go to scienceconf.deltacouncil.ca.gov. Stephen McCord, MEI: A recent series of articles covered issues in the Delta, many of which touch on mercury-related issues. Visit science.kqed.org/quest/series/californias-deadlockeddelta/. Stephen McCord, MEI: KQED radio presented a recent piece on the gold rush legacy. Several DTMC participants are quoted. Visit SRWP DTMC Meeting Summary Page 1

2 Alyce Ujihara, DPH (via ): The California Water Quality Monitoring Council ( has established a committee, the Bioaccumulation Oversight Group ( ight_group/), that is charged with coordinating monitoring, assessment, and communication of information relating to bioaccumulation in California. The Group is hosting a Monitoring Council Symposium on Bioaccumulation in California on December 17 in Richmond. Registration information and logistical details are available at Stephen McCord, MEI: A simple, inexpensive new technology developed by a Swiss- American team uses a strip of glass covered with a film of hairy nanoparticles. When an ion a positively charged particle, such as a methylmercury or cadmium ion gets in between two hairs, the hairs close up, trapping the pollutant. A voltage-measuring device can be calibrated because more ions trapped in the nano-velcro conduct more electricity. Read more at blogrssfeed+%28scienceblog.com%29&utm_content=google+reader#y3mlusy6q8rv5lf0. 99 Gary Sharpe, BLM Ukiah: (1) The Chicago and Research mines site ( is located in the Dry Creek Mining District, a tributary of Upper Putah Creek southwest of Middletown. BLM publicized a draft Engineering Evaluation and Cost Analysis (EE/CA) in late 2011 for capping excavation and consolidation of mercury calcine mill waste piles. (2) BLM is developing a removal action at Clyde Mine on Walker Ridge. Charlie Alpers, USGS: Studies of stream-bank erosion along the South Yuba River near the confluence with of Humbug Creek are using high-resolution LIDAR to quantify erosion rates of legacy hydraulic mining debris. Upstream Humbug Creek at the Malakoff Diggins State Historic Park mine site, six graduate students from CSU Chico (under the direction of Carrie Monohan) are conducting research at the site for their master s thesis projects and to support a watershed assessment that should inform development of control plans for sediment, mercury, and copper. The Sierra Fund will be hosting a stakeholder meeting in spring Bob Schneider, Tuleyome: Tuleyome s cleanup project at the Corona and Twin Peaks mine site is progressing on schedule. Current (year 1) activities include monitoring adit and creek discharges, testing discharge treatment options and parameters, and addressing applicable regulations. Next steps are to complete CEQA review and documentation, applying for permits, developing soil and water treatment plans, and hosting site visits for stakeholders. Visit for more information. III. Mercury TMDL Activities Patrick Morris and Janis Cooke, Regional Board: (1) A draft strategy for a Mercury Exposure Reduction Program is undergoing internal review. Staff will organize a workgroup to produce a workplan based on the strategy by October 2013; (2) The Delta MeHg TMDL s Technical Advisory Committee (TAC) met on Sept to review concept proposals both with the entire stakeholder group and with individual groups who submitted outlines; (3) for the statewide reservoirs mercury TMDL, staff are still working on data analysis and SRWP DTMC Meeting Summary Page 2

3 anticipate hosting meetings on that and the fish tissue objectives by mid For more information visit Stephen McCord, McCord Environmental: (1) The NPS Workgroup is compiling and prioritizing site studies, and identifying funding needs and opportunities; (2) the CVCWA wastewater special project group is coordinating influent and effluent monitoring. Amanda Palumbo, SWRCB: The wetlands policy is on hold indefinitely, and anyway it has no specifics on mercury. But dredge and fill activities (which usually involve wetlands) require a 401 certification. The 401 certification should include requirements for any special concerns or activities in an area, such as a mercury TMDL. IV. Presentations Five presentations were given: (1) Rathburn Abandoned Mercury Mine (Gary Sharpe, BLM); (2) Wastewater treatment comparison study (Kathryn Gies, West Yost Assoc.); (3) SRCSD Pilot Project MeHg Study (Lysa Voight and Nan Bailey, SRCSD); (4) Mercury Simulation Modeling (Sujoy Roy, TetraTech); and (5) Cache Creek Settling Basin Mercury Studies (Charlie Alpers and Josh Ackerman, USGS). 1 Rathburn Abandoned Mercury Mine Overview of this mine cleanup project in the Cache Creek watershed (Gary Sharpe, BLM) The mine site is along Walker Ridge, north of CA Hwy. 20 in the Bear Creek watershed (Cache Creek tributary). Mine waste rock is scattered on site, but almost all of the ore was processed elsewhere. Consequently, mercury levels in sediments are low ( ppm) relative to other mercury mine sites. Most of the site is on BLM land, although portions of the Petray Mine are on private land where BLM cannot work. Major analyses to date include a Removal Site Investigation and an Engineering Evaluation / Cost Analysis. Because the site was mined as an open pit, the major remediation action is to fill in the pits with mining waste, cover the soil with locally-borrowed surficial soils, contour the repository to minimize erosion, hydroseed, and install straw bales for erosion control. Other borrow areas on nearby BLM land were deemed unsuitable for revegetating the sites as they would encourage invasive species. Rathburn North also has a sediment trap below the pit area. The trap is not expected to methylate mercury because it drains quickly through rock fissures. Minimal signage has been installed to explain or alert visitors about the site s condition or sensitivity to off-road vehicles. BLM cannot legally close the road and they have had some problems with vandalism. This CERCLA removal action is being done piecemeal as funds are available. The east pit is being studied, North Petray pit is being designed, and nothing is occurring on private land for the South Petray pit. For more information: Gary Sharpe, Wastewater treatment comparison study Review of control study workplan and initial findings (Kathryn Gies, West Yost Assoc.) Seventeen wastewater agencies in and around the Delta are participating in a special project to comply with the Delta Methylmercury TMDL and to collectively generate relevant information on methylmercury (MeHg) levels in and control options for wastewater. For context, all SRWP DTMC Meeting Summary Page 3

4 wastewater dischargers combined currently represent less than 5% of the total MeHg load to the Delta. Furthermore, each in-delta facility in addition (and so collectively as well) appears to be meeting its final TMDL wasteload allocation. Also, there do not appear to be any bad actors that stand out as having higher MeHg relative to others with the same treatment train. The control study approach is to: Characterize MeHg removals at the participating plants Quantify the MeHg removal effectiveness for various levels of treatment and identify relationships between treatment processes and effectiveness in removing MeHg. Extrapolate the water quality for effective treatment strategies to all plants (i.e., what if all plants were upgraded to the most effective processes?) and estimate impacts to the overall wastewater MeHg load if the best available technologies were applied across the board. The hypothesis to be tested in general is that the net effect of various wastewater plant upgrade scenarios will be significant. Scenarios to be tested against the baseline (current effluent conditions) include: All upgrades already or expected to be required by NPDES permits are done. All plants evaluated under this study provide at least conventional nitrification treatment All plants evaluated under this study provide at least conventional nitrificationdenitrification treatment All plants evaluated under this study provide at least conventional nitrificationdenitrification treatment and Title 22 filtration (or equivalent). The effect of varying influent MeHg concentrations will also be evaluated by treatment train. Although the data available currently indicate a weak positive correlation between nitrate concentrations and MeHg concentrations, removing all nitrate has the potential to increase MeHg concentrations. The Technical Advisory Committee (TAC) agreed with this approach, but asked for additional details on specific types of treatment technologies and MeHg removal mechanisms. Participating plants have begun sampling influent and effluent for this study. Data will be collected through October 2014, and reported in 2015 to the TAC. For more information: Kathryn Gies, kgies@westyost.com, SRCSD Pilot Project MeHg Study Mercury-related monitoring at a pilot treatment system comparing various treatment trains for methylmercury removal (Lysa Voight and Nan Bailey, SRCSD) Located in Elk Grove south of the Sacramento metropolitan area, the Sacramento Regional Wastewater Treatment Plant (SRWTP) treats about 141 million gallons per day (mgd) from more than 1.3 million residents. Treated wastewater is discharge to the Sacramento River near Freeport. To address its new NPDES discharge permit (which is being contested in court on various issues), engineers have constructed and are operating a 0.25 mgd facility with multiple treatment trains to support full-scale design choices and scaling. The upgrades may include biological nutrient removal, filtration, and new disinfection based on the current NPDES permit. SRWP DTMC Meeting Summary Page 4

5 Mercury-related monitoring is an add-on component to the overall pilot project, which includes all constituents with permit limits, several performance test parameters, and various constituents of emerging concern. Consequently, staff members need to be flexible and responsive to maintenance schedules, operational changes, and system interruptions. The sampling period is May 2012 February 2013, which was originally scheduled to provide nearly 30 sets of samples for MeHg and several ancillary parameters (ph, nitrogen species, disinfection doses, DO, temperature, DOC, and TSS). The sample plan has had to be adaptable due to pilot project schedules, equipment availability, etc. They are mostly interested in sampling the granular media filters with and without pre-ozonation, and the UV and ozone disinfection systems. SRCSD evaluated the value of sampling after chlorine disinfection, but the MeHg was <0.02 ng/l. Initial results show similarly low levels after just N/DN air activated sludge (before filtration and disinfection). For more information: Lysa Voight, Mercury Simulation Modeling Current and needed tools and capabilities for mercury modeling in the Delta region (Sujoy Roy, TetraTech) Mercury modeling to date has been as correlations between MeHg levels in water and in fish tissue. A process-based simulation model could be applied with features such as complexation, methylation/demethylation, food-web uptake, and losses/gains from volatilization/deposition and particle settling/burial/scouring. A process-based model would allow a broad set of stakeholders to integrate processes studied separately other processes and from the Delta scale, explore effects of various management alternatives, identify remaining knowledge gaps, and link with other concerns such as salinity and turbidity. Such a tool would illuminate the effects of requirements set forth in the implementation phase of the Delta MeHg TMDL. The proposed modeling approach is to focus on water column mercury and MeHg initially, link DWR s DSM2 Delta water quality model with existing watershed models for the major tributaries, and link with land-use specific sub-models for non-point sources that contribute to the Delta. Future improvements could add a food-web component and track reactive mercury explicitly. Data needs seem extensive, but many of the useful constituents have or are being monitored currently in water and sediments. Spatially, more sites in the central Delta would be helpful, but not critical. Detailed studies to estimate process rate constants would also be useful. Locations and land uses such as the Yolo Bypass are likely unique enough to warrant their own sub-model. Although the modeling objectives are daunting, a promising example exists already for selenium, which has several similar characteristics as mercury, simulated in north San Francisco Bay. For more information: Sujoy Roy, Sujoy.Roy@tetratech.com, Cache Creek Settling Basin Mercury Studies Overview of recent and upcoming mercury studies for the basin (Charlie Alpers and Josh Ackerman, USGS) The Cache Creek Settling Basin (CCSB) is a sediment trap built by the Corps of Engineers in 1937 and modified in 1993 to reduce sediment deposited in the Yolo Bypass, which protects the City of Sacramento from flooding. Although trapping ~50% of the sediment load currently, the Delta MeHg TMDL requires DWR to trap at least 75% of the incoming sediment and total Hg SRWP DTMC Meeting Summary Page 5

6 load. An ongoing management challenge in the basin is balancing THg load reduction with possible increases in MeHg production and export. Ongoing research by USGS scientists and UC Davis researchers is being funded by the Department of Water Resources (DWR). The studies goal is to provide DWR and other stakeholders with data and interpretive reports on mercury needed for future management of the Cache Creek Settling Basin (CCSB). Although providing only ~2% of the discharge of the Sacramento R. watershed, Cache Creek discharges up to 30% of Hg load of the entire Sacramento R. watershed and ~60% of Hg load into the Yolo Bypass (according to the Delta MeHg TMDL reports). The study includes monitoring in and around the CCSB at the inflow, in-basin sediments, and both outflows (low-flow drain and weir spillway). The study will evaluate both in-vs-out and inbasin conditions. Phase I monitoring was conducted Dec April Baseline sampling for mercury and several ancillary parameters was conducted at 3-week intervals during the wet season; storm event sampling included 8-10 samples per year (rising, peak, and falling limbs of the hydrograph). Interesting findings to date include: SSC and THg typically decrease from inflow to outflow, but not always at lower flows The MeHg content (mass MeHg per mass SS) is higher in outflow than in inflow Sediment MeHg/THg was higher in non-agricultural riparian areas than in agricultural areas (corn fields) Deep cores analyzed for 137 Cs indicate a deposition rate of ~2 cm/yr ( ), which is of similar magnitude to modeled estimates by the U.S. Army Corps of Engineers, which were used to determine the basin s operation and maintenance schedule Phase II work planned for will continue to monitor inflows and outflows, sample inbasin water and sediment (~40 sampling sites in 4 zones along flow path), conduct sediment methylation potential experiments, and conduct more biological sampling (birds eggs from nests in bird boxes and blood from birds trapped temporarily in mist nets; caged mosquitofish). For more information: Charlie Alpers, cnalpers@usgs.gov, V. Meeting Wrap-Up Future Agenda Suggestions Mercury speciation in urban runoff Suisun Marsh Restoration modeling Western Region Mercury Synthesis Deer Creek tailings pile study Next Meeting Location and Time Time: Tuesday February 26, 2013, 12:30-4:30pm Location: DWR, 3500 Industrial Blvd., West Sacramento, CA SRWP DTMC Meeting Summary Page 6