Monitoring Remedial Effectiveness in a River System JR Flanders - URS Corp Ralph Stahl, Jr., PhD, DABT DuPont CRG November 11, 2014 SETAC North America Annual Meeting Vancouver, BC
Goals and Objectives of Monitoring Overall goal: - Assess efficacy of remedy to reduce transport and exposure pathways - Secondarily to improve WQ and bank habitat Specific objectives are to monitor: - Human and ecological exposure to mercury - System responses to remediation - Integrity of corrective action; and - Provide input to adaptive management framework and relative risk models
Monitoring Features Monitoring is: - Front-loaded - Iterative, and may be scaled back or modified pending results, and Contains short-term and long-term elements - Differ in terms of spatial and temporal scope - Similar overall goals
Short-Term Monitoring Objectives Objective: test effectiveness of Phase I Interim Measure - Bank stabilization between RRM 0 to 2 to reduce: Bank erosion Mercury loading In-channel mercury exposure Short time frame (2-10 years) Small spatial scales (BMAs) Remediation of downstream reaches informed by remedy success on RRM 0-2
Short-Term Monitoring Elements 11 locations within RRM 0-2 Potential exposure media to be evaluated: - Near-bank Sediment -Periphyton - Transplanted Asiatic Clams -Pore Water Vegetation/Habitat Monitoring Monitoring activities to begin in 2015
Results of Pilot Bank Stabilization: 2009 to 2014
Long-Term Monitoring Timeframe is >10 years Focus is South River and SFS River Objectives: - Monitor human exposure to MeHg in food - Monitor ecological exposure to MeHg in aquatic and terrestrial food web - Monitor potential improvements to water quality and benthic habitat Three main components - Human exposure - Ecological exposure Aquatic and terrestrial - Habitat quality
Human Exposure Monitoring Three potential exposure media are being evaluated: - Adult Smallmouth and Largemouth Bass - Snapping Turtles - Mallard Ducks Once annual monitoring 13 monitoring locations - South River (4) - South Fork Shenandoah (7) - Shenandoah (2) Community outreach - Signage - Physician and clinic outreach - Angler surveys - Outreach to non-english speaking communities
Summary of Bass Tissue Results Notes: SMB = smallmouth bass, LMB = largemouth bass, SR = South River, SF = South Fork Shenandoah River, SH = Shenandoah River, THg = Total mercury, MeHg = Methylmercury, LTM = Long- Term Monitoring Program. Data are shown as concentrations of mercury species in fish fillets (mean standard deviation). Data are limited to fish >170mm total length sampled within the LTM sample location reaches from 2000 to 2014.
Aquatic Ecological Exposure Monitoring Three potential exposure media are being evaluated: - Asiatic Clams - Mayflies - Periphyton - Sediment - Young-of-Year Smallmouth Bass Benthic Community Assessment Eight Monitoring Locations - South River (5) - South Fork Shenandoah (2) - Middle River (1) (Reference Area)
Trophic Level 2 Trophic Level 3 Trophic Level 4 Trophic Level 1 South River Terrestrial Mercury Trophic Transfer Diagram Legend Isotope data available Items in bold are focal species in ERA Isotope data not available Predatory Bird (Screech Owl, Red-tailed hawk) Herbivorous Mammals (White-tailed Deer) Box height proportional to variability of trophic position in model Sources: Newman, M. 2011. Trophic Analysis and Modeling. Harrisonburg, VA. October. Newman et al. 2011. Environ. Poll. 159 (10): 2840-2844. Small Mammals (Deer mouse) Vegetatio n Soil Insectivorous Bird (Tree Swallow, Bluebird, Phoebe, Song sparrow) Grainivorous Birds (Cardinal, Titmouse, Towhee) Herbivorous Insects (Tent Caterpillar) Invertivorous Mammals (Shrew) Detritus Insectivorous Mammals (Big brown bat) Predatory Invertebrates (Spiders) Aquatic Invertebrates Detritivores (Isopods, Annelids)
Terrestrial Ecological Exposure Monitoring Four potential exposure media are being evaluated: - Earthworms and Soil - Wolf Spiders - Carolina Wren Nine Monitoring Locations - South River (5) - South Fork Shenandoah (4)
Water Quality and Benthic Habitat Quality South River benthic habitat impaired RRM 0 to 14: - Phosphorous and sedimentation - May improve slowly as BMPs adopted Surface water: - Interannual variability - Long-term data set
How Will the Data be Used? DATA SOURCES South River Database Long-Term Monitoring Data Update relative risk model: Mercury in biota Life history data Water quality data (temperature, dissolved oxygen) DATA INTEGRATION Relative Risk Model Comparison of short-term data with long-term data Comparison with long-term trends in climate data Methylation status of river Use results of relative risk model to adjust management alternatives Short-Term Monitoring Data Before-after comparison of data Place short-term monitoring results in context of long-term trends Test hypotheses Adaptive Management Plan Following periodic review of management program, adjust monitoring as necessary.
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