Memorandum. Riparian and aquatic habitat Benthic community structure River access / aesthetics

Transcription

1 Meorandu AECOM 625 West Ridge Pike, Suite E100 Conshohocken, Pennsylvania tel fax To CC Subject Fro Michael Liberati, DuPont CRG Ralph Stahl, DuPont CRG Page 1 of 2 Nancy Grosso, DuPont CRG Cecilia Mancini, AECOM Area of Concern AOC) 4 Short-Ter Monitoring STM) 2015 Biannual Monitoring Joshua Collins, AECOM Date January 11, 2016 In accordance with the United States Environental Protection Agency US EPA) Resource Conservation and Recovery Act RCRA) Corrective Action Perit, interi easures are being ipleented by E.I. du Pont de Neours and Copany DuPont) to address ercury released to the South River fro the forer DuPont facility in Waynesboro, Virginia. Preliinary Phase 1) interi easures are focused on bank stabilization, which will be ipleented at Bank Manageent Areas BMAs) beginning with the first two relative river iles RRM), RRM 0 to RRM 2.0 downstrea of the site Anchor QEA, et al, 2015). Phase 1 BMAs are divided into Priary and Secondary BMAs. Phase 1 Priary BMAs consist of banks that contribute disproportionately to THg loading between RRM 0 and RRM 2; loadings fro Phase 1 Secondary BMAs contribute substantial but less than loadings fro Phase 1 Priary BMAs. Phase 1 Priary and Secondary BMAs are further divided into Phase 1A and Phase 1B based on land ownership. Phase 1A BMAs include all City-owned Priary BMAs, as well as City-owned Secondary BMAs that are located iediately adjacent to City-owned Priary BMAs. The reaining City-owned Secondary BMAs and non-city-owned BMAs fro RRM 0 to RRM 2 are classified as Phase 1B BMAs. To evaluate the perforance of the interi easures and proposed reedial approach, Short- and Long-Ter Monitoring STM and LTM, respectively) is being conducted. STM is intended to evaluate the effectiveness of the reedial approach over a short period of tie i.e., two to ten years) within a liited spatial extent i.e., adjacent to a particular BMA). STM evaluates the following: Bank stability Total ercury THg) and ethylercury MeHg) concentrations in: o Sedient o Pore water o Periphyton o Asiatic clas Corbicula fluinea) Additional habitat assessents and public access feature surveys were also conducted in order to address stakeholder concerns. These assessents include the following: Riparian and aquatic habitat Benthic counity structure River access / aesthetics This technical eorandu suarizes the June and October 2015 STM events, which were conducted to assess pre-reediation i.e., baseline) conditions. An annual STM report is being

2 prepared that will provide a ore detailed description of 2015 STM data and will be subitted in the first quarter of The June and October 2015 STM events focused on Short-ter Monitoring Plan locations STMP) - 01, -05, and -07 Figure 1). Monitoring was conducted in accordance with the Final AOC 4 Short-ter Monitoring Plan URS Corporation, 2015). Table 1 provides an overview of the onitoring plan design, including perforance objectives, etrics, success criteria, and adaptive anageent outcoes; additional detail is provided in the Monitoring Plan and associated appendices. Based on the field investigations: Banks at STMP-01, -05, and -07 were generally stable with localized areas of erosion based on a visual survey. Mercury concentrations in sedient, pore water, and periphyton were generally coparable between sapling events, but were highly variable within each BMA Tables 2, 3, and 4). Asiatic clas collected during the June sapling event had higher ercury concentrations copared to the October event Table 5). Mercury concentrations in periphyton and Asiatic clas collected fro near bank environents were generally higher than concentrations in those collected fro id-channel environents. The following points suarize the ancillary assessents entioned above: Existing canopy cover at each STMP was liited. High densities of invasive species were present at STMP-01, but were not as prevalent at STMP-05 or -07. Sedient grain size distribution at STMP-01 and -05 was norally distributed and consisted priarily of coarse gravel and sall to ediu cobble, respectively. STMP-07 displayed a ore even grain size distribution, with a larger proportion of saller grain sizes. Results of benthic counity saple analyses will be available in January Vegetation at STMP-01 and -05 had been cleared to provide access along foot paths, presuably for fishing Figure 1). STMP-07 had few cleared paths likely due to its location adjacent to the City of Waynesboro wastewater treatent plant. The annual report will provide a ore detailed description of the results of the 2015 STM sapling efforts. Consistent with adaptive anageent principles, the annual STM report will also include suggested recoendations for corrective actions or odifications to the plan, if warranted. REFERENCES Anchor QEA, URS Corporation, E.I. du Pont de Neours and Copany Final Interi Measures Design, Ipleentation, and Monitoring Work Plan. Phase I - South River Area of Concern pp. URS Corporation Final AOC 4 Short-ter Monitoring Plan - Relative River Mile 0-2 of the South River, Virginia. 28 pp. 2

3 O 2nd STMP-01e STMP-0 1 Railroad Bridge Broad Main Invista Footbridge STMP-01a Benthic Counity Location Near bank and Mid-channel Periphyton/Cla Collections Extent of Short-ter Monitoring Location Phase 1A Priary BMAs Phase 1A Secondary BMAs Phase 1B Priary BMAs Phase 1B Secondary BMAs Sapling Transect c [ Legend Feet River Access LWD Job: West Ridge Pike, Suite E-100 Conshohocken, PA Phone: 610) Fax: 610) Prepared by: VP Checked by: BR Date: 10/28/2015 C:Userskyle_arndtDesktopNew folderfigure 1 Short-ter Monitoring Location Extent Maps - Transects xd Shoreline Reference: VBMP Recent Aerial Iagery 1.) Clay and Silt Deposits 2.) Fine Sand Deposits Staunton Rockingha Augusta Waynesboro Albearle Nelson Figure 1: Sheet 1 of 3 Short-ter Monitoring Locations Overview Map AOC 4 Short-Ter Monitoring Plan Forer Dupont Waynesboro Plant Waynesboro, Virginia

4 O 2nd 3 40 Railroad Bridge Broad Main Invista Footbridge STMP-05j 2 50 M ST P- 05 STMP-05a Benthic Counity Location Near bank and Mid-channel Periphyton/Cla Collections Extent of Short-ter Monitoring Location Phase 1A Priary BMAs Phase 1A Secondary BMAs Phase 1B Priary BMAs Phase 1B Secondary BMAs Sapling Transect c [ Legend Feet River Access LWD Job: West Ridge Pike, Suite E-100 Conshohocken, PA Phone: 610) Fax: 610) Prepared by: VP Checked by: BR Date: 10/28/2015 C:Userskyle_arndtDesktopNew folderfigure 1 Short-ter Monitoring Location Extent Maps - Transects xd Shoreline Reference: VBMP Recent Aerial Iagery 1.) Clay and Silt Deposits 2.) Fine Sand Deposits Staunton Rockingha Augusta Waynesboro Albearle Nelson Figure 1: Sheet 2 of 3 Short-ter Monitoring Locations Overview Map AOC 4 Short-Ter Monitoring Plan Forer Dupont Waynesboro Plant Waynesboro, Virginia

5 O 2nd STMP-07k Railroad Bridge Broad Main Invista Footbridge M ST P- 07 STMP-07a c [ Benthic Counity Location Near bank and Mid-channel Periphyton/Cla Collections Extent of Short-ter Monitoring Location Phase 1A Priary BMAs Phase 1A Secondary BMAs Phase 1B Priary BMAs Phase 1B Secondary BMAs Sapling Transect c [ Legend Feet River Access LWD Job: West Ridge Pike, Suite E-100 Conshohocken, PA Phone: 610) Fax: 610) Prepared by: VP Checked by: BR Date: 10/28/2015 C:Userskyle_arndtDesktopNew folderfigure 1 Short-ter Monitoring Location Extent Maps - Transects xd Shoreline Reference: VBMP Recent Aerial Iagery 1.) Clay and Silt Deposits 2.) Fine Sand Deposits Staunton Rockingha Augusta Waynesboro Albearle Nelson Figure 1: Sheet 3 of 3 Short-ter Monitoring Locations Overview Map AOC 4 Short-Ter Monitoring Plan Forer Dupont Waynesboro Plant Waynesboro, Virginia

6 Table 1 AOC-4 Short-Ter Monitoring Suary South River and a Segent of the South Fork Shenandoah River Forer DuPont, Waynesboro Plant, Virginia Short-Ter Reedial Action Objectives Monitoring Plan Designs Adaptive Manageent Outcoes General Objective Perforance Objective Measurable Metric Preliinary Success Criteria General Station Locations Monitoring Frequency Analytical Paraeters Contingency Actions Decision Analysis Topography Reduced Annual Erosion Rate Shore Based LiDAR Surveys Conducted at Each BMA Annually for First 3 ears; Post-stor Average Annual Erosion Rate Structural and/or Vegetative Stabilization Increase in Bank Stability Vegetation >80% Cover; <10% Invasives Vegetation Plots at Each BMA ears; Post-stor Cover and Species Coposition Additional Vegetation Enhanceent Design and Ipleentation Landowner Approvals and Perits BMA Properties NA NA NA Refine Ipleentation Surface Sedient >75% Mercury Concentration Reduction Transects Spaced ~ ' at each BMA ears IHg and MeHg Concentrations NA Reduce Mercury Transport and Exposure Reduce Mercury Pore Water >75% Mercury Concentration Reduction Transects Spaced ~ ' at each BMA ears IHg and MeHg Concentrations NA Loading fro Bank Periphyton >75% Mercury Concentration Reduction Downstrea of Representative BMAs Nearshore) ears IHg and MeHg Concentrations NA Asiatic Cla Sapling >75% Mercury Concentration Reduction Downstrea of Representative BMAs Nearshore) ears IHg and MeHg Concentrations NA Reduce In- Periphyton >50% Mercury Concentration Reduction Downstrea of Representative BMAs Channel) Annually for First 10 ears IHg and MeHg Concentrations NA Refine CSM Channel Mercury Exposure Asiatic Cla Sapling >50% Mercury Concentration Reduction Downstrea of Representative BMAs Channel) Annually for First 10 ears IHg and MeHg Concentrations NA Refine CSM Iprove Bank Vegetation Vegetation >80% Cover; <10% Invasives Vegetation Plots at Each BMA ears Cover and Species Coposition Additional Vegetation Enhanceent Iprove In- Strea Habitat Rapid Bioassessent Protocols Visual Strea Classification Each BMA Assessed Independently Quarterly for the First ear and Sei Annually Q1/Q3) for years 2-10 Rapid Bioassessent Protocol Scores NA Maintain or Iprove Riparian and Aquatic Habitat Maintain Detrital Input/Strea Shading Maintain Strea Substrate Condition Percent Canopy Coverage Canopy Cover Achieveent of Baseline Canopy Coverage Transects Spaced ~ ' at each BMA Annually for First 3 ears Spherical Densioeter) Maintenance / Iproveent of Baseline Wolan Pebble Counts Transects Spaced ~ ' at each BMA Annually for First 3 ears Particle Size Analysis Conditions Additional Vegetation Enhanceent Structural and/or Vegetative Stabilization Maintain Instrea Habitat Features # of In-strea Habitat Features Maintenance / Iproveent of Baseline Conditions Each BMA Assessed Independently ears # of In-strea Habitat Features Structural Stabilization Habitat Function and Ecological Value EPW & USM Maintenance / Iproveent of Baseline Conditions Each BMA Assessed Independently Annually for first 3 ears USM Methodology & EPW Non-tidal Strea - Fish FCI Structural and/or Vegetative Stabilization Maintain or Iprove Benthic Counity Maintenance of Benthic Counity Benthic Invertebrate Metrics Maintenance / Iproveent of Baseline Conditions Four Locations Within the Interi Measures Area RRM 0.5, RRM 1.0, RRM 1.5, RRM 2.0) ears 300 Organis Sub-count NA River Access / Aesthetics Provide Stable River Access Points Stable Access Points Maintenance / Iproveent of Baseline Conditions Each BMA Assessed Independently # of Stable and Iprovised Access ears Points Structural Stabilization Notes: EPW, Evaluation for Planned Wetlands FCI, Functional Capacity Index USM, Unified Strea Methodology RRM, Relative River Mile NA, Not Applicable, Ancillary Habitat/Public Access etrics

7 Table 2 Sedient IHg and MeHg Monitoring Suary Short-Ter Monitoring DuPont South River AOC 4 Saple ID Sedient Type IHg June g/kg dw) IHg Oct. g/kg dw) MeHg June µg/kg dw) MeHg Oct. µg/kg dw) A 0.11 STMP B C Bulk D E STMP-05 A B C D E Bulk F G H I J STMP-07 A B C D E F Bulk G H I J K Notes: IHg, Inorganic ercury MeHg, Methylercury g/kg dw, Milligras per Kilogra dry weight

8 Table 3 Pore Water FIHg and FMeHg Monitoring Suary Short-Ter Monitoring DuPont South River AOC 4 Saple ID FIHg June ng/l) FIHg Oct. ng/l) FMeHg June ng/l) FMeHg Oct. ng/l) A B C D E STMP-05 A B C D E F G H I J STMP-07 A B C D E F G H I J K Notes: FIHg, Filtered inorganic ercury FMeHg, Filtered ethylercury ng/l, Nanogras per Liter STMP-01

9 Table 4 Periphyton IHg and MeHg Monitoring Suary Short-Ter Monitoring DuPont South River AOC 4 Saple Replicate Notes: Environent IHg, Inorganic ercury MeHg, Methylercury µg/kg ww, Microgras per Kilogra wet weight --, Not sapled IHg June µg/kg ww) STMP-01 IHg Oct. µg/kg ww) MeHg June µg/kg ww) MeHg Oct. µg/kg ww) A B Mid-Channel C A B Near Bank C STMP-05 A B Mid-Channel C A B Near Bank C STMP-07 A B Mid-Channel C A B Near Bank C

10 Table 5 Corbicula IHg and MeHg Monitoring Suary Short-Ter Monitoring DuPont South River AOC 4 Saple Replicate Environent IHg June IHg Oct. µg/kg ww) µg/kg ww) STMP-01 MeHg June µg/kg ww) MeHg Oct. µg/kg ww) A Mid-Channel B C A Near Bank B C A Near-Bank B Seeded C STMP-05 A Mid-Channel B C A Near Bank B C A Near Bank B Seeded C STMP-07 A Mid-Channel B C A Near Bank B C A Near Bank B Seeded C Notes: IHg, Inorganic ercury MeHg, Methylercury µg/kg ww, Microgras per Kilogra wet weight --, Not sapled