Leesville Lake 2014 Water Quality Monitoring

Transcription

1 Leesville Lake 2014 Water Quality Monitoring Prepared for: Leesville Lake Association Prepared by: Dr. Thomas Shahady Lynchburg College Funds Supplied by: American Electric Power & Leesville Lake Association February 9, 2015

2 2014 Report - Leesville Lake Water Quality Monitoring (Page Left Intentionally Blank) ii

3 2014 Report - Leesville Lake Water Quality Monitoring Table of Contents List of Tables. List of Figures List of Maps... List of Acronyms and Abbreviations.... Page iv v vi vii Executive Summary... ix Section 1: Introduction... 1 Section 2: Historical Data Section 3: Current Conditions (Year 2014) General Methods Water Quality: Current Test Results (Year 2012) Temporal Analysis by Station Dam (Lacustrine) Mile Marker 6 (Transition) Toler Bridge (Riverine) Other Data Section 4: Lake Wide Trending Analysis of Trophic State Analysis of Pigg River. Section 4: Management Implications..... References... Appendix A: Water Parameter Testing Details... Appendix B: Quality Assurance (QA) / Quality Control (QC).. Appendix C: Quality Assurance (QA) / Quality Control (QC) Checklist iii

4 2014 Report - Leesville Lake Water Quality Monitoring List of Tables ID Table Description Page 3.0 Leesville Lake 2014 Sampling Sites Dam (Lacustrine) Conductivity (µs/cm) Measures Over Study Period (2014) Dam (Lacustrine) Dissolved Oxygen (mg/l) Measures Over Study Period 11 (2014) 3.3 Dam (Lacustrine) Temperature (Degrees C) Measures Over Study Period 13 (2014) 3.4 Typical Trophic State Indicators For Lakes Dam (Lacustrine) Fluorometer Measured Chlorophyll a (ppb) (Degrees C) 16 Measures Over Study Period (2014) 3.6 Dam (Lacustrine) ph Measures Over Study Period (2014) Dam (Lacustrine) ORP Measures Over Study Period (2014) Dam (Lacustrine) Turbidity (NTU) Measures Over Study Period (2014) Dam (Lacustrine) Other Parameters Over Study Period (2014) Mile Marker 6 (Transition) Conductivity (µs/cm) Measures Over Study Period 25 (2014) 3.11 Mile Marker 6 (Transition) Dissolved Oxygen (mg/l) Measures Over Study 27 Period (2014) 3.12 Mile Marker 6 (Transition) Temperature (Degrees C) Measures Over Study 29 Period (2014) 3.13 Mile Marker 6 (Transition) Fluorometer Measured Chlorophyll a (ppb) 30 (Degrees C) Measures Over Study Period (2014) 3.14 Mile Marker 6 (Transition) ph Measures Over Study Period (2014) Mile Marker 6 (Transition) ORP Measures Over Study Period (2014) Mile Marker 6 (Transition) Turbidity (NTU) Measures Over Study Period 34 (2014) 3.17 Mile Marker 6 (Transition) Other Parameters Over Study Period (2014) Toler Bridge (Riverine) Conductivity (µs/cm) Measures Over Study Period 37 (2014) 3.19 Toler Bridge (Riverine) Dissolved Oxygen (mg/l) Measures Over Study 38 Period (2014) 3.20 Toler Bridge (Riverine) Temperature (Degrees C) Measures Over Study Period 40 (2014) 3.21 Toler Bridge (Riverine) Fluorometer Measured Chlorophyll a (ppb) (Degrees 41 C) Measures Over Study Period (2014) 3.22 Toler Bridge (Riverine) ph Measures Over Study Period (2014) Toler Bridge (Riverine) ORP Measures Over Study Period (2014) Toler Bridge (Riverine) Turbidity (NTU) Measures Over Study Period (2014) Toler Bridge (Riverine) Other Parameters Over Study Period (2014) Pit Stop Marina Other Parameters Measured Over Study Period (2014) 46 iv

5 2014 Report - Leesville Lake Water Quality Monitoring List of Tables Cont Tri County Marina Other Parameters Measured Over Study Period (2014) Mile Marker 9 Other Parameters Measured Over Study Period (2014) Smith Mountain Lake Tail Waters Other Parameters Measured Over Study 47 Period (2014) 3.30 Pigg River Other Parameters Measured Over Study Period (2014) Pigg River Dissolved Oxygen (mg/l) Measures Over Study Period (2014) Pigg River Temperature (Degrees C) Measures Over Study Period (2014) Pigg River ph Measures Over Study Period (2014) Pigg River Conductivity (µs/cm) Measures Over Study Period (2014) Pigg River Turbidity (NTU) Measures Over Study Period (2014) Pigg River ORP Measures Over Study Period (2014) Comparable statistics between Smith Mountain Lake and Leesville Lake. 57 List of Figures ID Figure Description Page 3.1 Dam (Lacustrine) Conductivity (µs/cm) Measures Over Study Period 9 (2014) 3.2 Dam (Lacustrine) Dissolved Oxygen (mg/l) Measures Over Study 11 Period (2014) 3.3 Dam (Lacustrine) Temperature (Degrees C) Measures Over Study Period 13 (2014) 3.4 Dam (Lacustrine) Fluorometer Measured Chlorophyll a (ppb) (Degrees 15 C) Measures Over Study Period (2014) 3.5 Dam (Lacustrine) ph Measures Over Study Period (2014) Dam (Lacustrine) ORP Measures Over Study Period (2014) Dam (Lacustrine) Turbidity (NTU) Measures Over Study Period (2014) Mile Marker 6 (Transition) Conductivity (µs/cm) Measures Over Study 24 Period (2014) 3.9 Mile Marker 6 (Transition) Dissolved Oxygen (mg/l) Measures Over 26 Study Period (2014) 3.10 Mile Marker 6 (Transition) Temperature (Degrees C) Measures Over 27 Study Period (2014) 3.11 Mile Marker 6 (Transition) Fluorometer Measured Chlorophyll a (ppb) 29 (Degrees C) Measures Over Study Period (2014) 3.12 Mile Marker 6 (Transition) ph Measures Over Study Period (2014) Mile Marker 6 (Transition) ORP Measures Over Study Period (2014) Mile Marker 6 (Transition) Turbidity (NTU) Measures Over Study 33 Period (2014) 3.15 Toler Bridge (Riverine) Conductivity (µs/cm) Measures Over Study 36 Period (2014) 3.16 Toler Bridge (Riverine) Dissolved Oxygen (mg/l) Measures Over Study Period (2014) 38 v

6 2014 Report - Leesville Lake Water Quality Monitoring List of Figures cont Toler Bridge (Riverine) Temperature (Degrees C) Measures Over Study 39 Period (2014) 3.18 Toler Bridge (Riverine) Fluorometer Measured Chlorophyll a (ppb) 41 (Degrees C) Measures Over Study Period (2014) 3.19 Toler Bridge (Riverine) ph Measures Over Study Period (2014) Toler Bridge (Riverine) ORP Measures Over Study Period (2014) Toler Bridge (Riverine) Turbidity (NTU) Measures Over Study Period 44 (2014) 4.1 Trophic State Index (TSI) based upon Secchi disk measurements in 47 Leesville Lake from Trophic State Index (TSI) based upon TP measurements in Leesville 48 Lake from Trophic State Index (TSI) based upon Chl a measurements in Leesville 49 Lake from Trophic State Index (TSI) based upon average measurements in Leesville 50 Lake from Daphnia abundance based upon average measurements in Leesville Lake 51 from The relationship between TP and Chlorophyll a years Trophic State Index (TSI) based upon TP measurements in Leesville Lake from List of Maps ID Map Description Page 2.1 Leesville Lake Water Quality Monitoring Stations w/ DEQ Identification Map of Pigg River and Old Woman s Creek Watersheds Map of Leesville Lake Area 6 vi

7 2014 Report - Leesville Lake Water Quality Monitoring List of Acronyms and Abbreviations AEP American Electric Power AFD Agricultural and Forest District BCLP Bedford Citizens for Land Conservation BCWPC Blackwater Creek Watershed Planning Committee BMP Best Management Practice BW Blackwater CEQ Council on Environmental Quality CFR Code of Federal Regulations cfs Cubic feet per second CVLC Central Virginia Land Conservancy Corps U.S. Army Corps of Engineers COW Code and Ordinance Worksheet CREP Conservation Reserve Enhancement Program CRP Conservation Reserve Program CSO Combined Sewer Overflow CSS Combined Sewer System CWP Center for Watershed Protection DCR Virginia Department of Conservation & Recreation DEQ Virginia Department of Environmental Quality DGIF Virginia Department of Game and Inland Fisheries DO Dissolved Oxygen EIS Environmental Impact Statement EPA United States Environmental Protection Agency EQIP Environmental Quality Incentives Program ESA Endangered Species Act ESC Erosion and Sediment Control FERC Federal Energy Regulatory Commission FPA Federal Power Act FWS U.S. Fish and Wildlife Service GIS Geographical Information Systems GLEN Greater Lynchburg Environmental Network HSPF Hydrological Simulation Program - FORTRAN JRA James River Association LC Lynchburg College Leesville Association Leesville Lake Association LID Low Impact Development LLA Leesville Lake Association MRLC Multi-Resolution Land Characterization NEMO Non-point Education for Municipal Officials NFWF National Fish and Wildlife Foundation NGVD National Geodetic Vertical Datum NLCD National Land Cover Data NPDES National Pollutant Discharge Elimination System NPS Non Point Source vii

8 2014 Report - Leesville Lake Water Quality Monitoring ORP PDR SAFETEA-LU Smith Mountain Association SMP SWCD SWM SCI TDR TDS TMDL TP TSI TSS USEPA USGS VDCR VDEQ VDGIF VDOT VOF WHIP Oxygen Reduction Potential Purchase of Development Rights Safe Accountable Flexible Efficient Transportation Equity Act: A Legacy for Users Smith Mountain Lake Association Shoreline Management Plan Soil and Water Conservation District Stormwater Management Stream Condition Index Transfer of Development Rights Total Dissolved Solids Total Maximum Daily Load Total Phosphorus Trophic State Index Total Suspended Solids United States Environmental Protection Agency United States Geological Survey Virginia Department of Conservation & Recreation Virginia Department of Environmental Quality Virginia Department of Game and Inland Fisheries Virginia Department of Transportation Virginia Outdoors Foundation Wildlife Habitat Incentives Program viii

9 2014 Report - Leesville Lake Water Quality Monitoring Executive Summary The Leesville Lake water quality monitoring program has several aspects: (1) monitor compliance with state water quality standards, (2) monitor eutrophication in the lake, and (3) make recommendations for identified problems. This report summarizes the findings under each of these aspects for the 2014 sampling year. Leesville Lake met all Virginia DEQ water quality standards for measured parameters including dissolved oxygen, temperature, ph, E coli and Chlorophyll a. For E. coli, no more than 10% of the total samples in the assessment period exceeded 235 E. coli CFU/100 ml threshold. Pigg River confluence continued to be the greatest area of concern for E. coli. Chlorophyll a seasonal averages in the lacustrine portion of the lake were 18.7 ug/l at the surface and 23.9 ug/l at 0.5 meters. Some measures between 4-6 meters depth were much higher but hydrology of the reservoir appears to mitigate this problem. Total phosphorus (TP) seasonal averages at dam surface were 79 ug/l. The lake continues to exhibit eutrophic conditions. Average trophic state index is 58.9 in the lake. This gives Leesville Lake a moderately eutrophic rating as values below 50 are necessary to classify the lake as mesotrophic. This is primarily a result of elevated TP and Chlorophyll a concentrations. Elevated ph measures during greatest point of productivity (up to 9) and low oxygen in the hypolimnion (as low as 1.83 mg/l) support this designation. It is hypothesized that pump back operations combined with Pigg River inputs are contributing to the eutrophic condition. Based upon analysis of current trends the following recommendations are made: Smith Mountain Lake (SML) operations should be correlated with water quality observations. The monthly tail water data collected for this report are helpful but only provide snap shot data of water quality exiting SML. Volumes of water pumped back and forth between Leesville Lake (LL) and SML, flow rates of Pigg River and times of dam operation are critical to proper understanding and potential management of water quality. Continued efforts to control Pigg River water quality are necessary. This remains a concern particularly during months of high energy generation at SML because pump back operations are more pronounced during these months. Leesville Lake is more vulnerable to water quality deterioration during high pumping into SML and high flow from the Pigg River because of the movement of water toward the SML dam increases contact time in Leesville Lake and the mixing effect it creates. Continued analysis and monitoring of zooplankton and forage fish populations in the reservoir are desirable. Improved water quality based upon zooplankton grazing is inferred from the persistent abundance of Daphnia in the reservoir. It is desirable to increase the populations of this species of zooplankton not only to improve the forage base for planktivorous fish, but also the water quality improvements this species brings. Game fish management to enhance and maintain this condition should be encouraged. ix

10 Section 1: Background of Water Quality Program For many years, the Virginia Department of Environmental Quality (DEQ) monitored Leesville Lake water quality either annually or biannually. Beginning in 2006, DEQ placed Leesville Lake on a six-year rotation for water monitoring. However, DEQ collected water quality data in 2009 and In an effort to supplement DEQ water quality monitoring, the Leesville Lake Association (LLA) began a Citizen Water Quality Monitoring Program in April Citizen volunteers monitored bacteria, Secchi depth, temperature, dissolved oxygen (DO), ph, and conductivity. LLA outlined four goals for the program: (a) gain a greater understanding of the lake s water quality, (b) supplement the DEQ water quality monitoring, (c) increase the community s awareness of the importance of water quality, and (d) inform residents about harmful factors that damage water quality and age the lake (Lobue, 2010). The Virginia DEQ provided LLA with a water quality monitoring probe to measure DO, temperature, and ph. With the DEQ Citizen Water Quality Monitoring Grant, LLA purchased Coliscan Easygel test kits for E. coli testing along with Secchi discs and other necessary equipment (Lobue, 2010). Over the next three years, LLA published annual reports of the water quality test results. As part of the water quality monitoring plan required by its new license, Appalachian Power Company committed $25,000 for a water quality monitoring program. Under the Federal Power Act (FPA) and the U.S. Department of Energy Organization Act, the Federal Energy Regulatory Commission has the power to approve licenses for up to 50 years for the management of non-federal hydroelectric projects (FERC, 2009, p. ii). The Commission issued the first license for the Smith Mountain Pumped Storage Project to Appalachian Power on April 1, 1960 with a set expiration date of March 31, 2010 (FERC, 2009). As part of its relicensing process, Appalachian Power was required by the Federal Energy Regulatory Commission to implement a Shoreline Management Plan (SMP). In July 2005, FERC approved a SMP proposed by Appalachian for the Smith Mountain Project. The purpose of this plan is to ensure the protection and enhancement of the project s recreational, environmental, cultural, and scenic resources and the project s primary function, the production of electricity. (FERC, 2009, p. 22). The SMP works to preserve green space, wetlands, and wildlife habitats along the shoreline. Property owners may not remove vegetation within the project boundary unless they have received permission from Appalachian Power. The project boundary for Leesville Lake lies at the 620-foot contour elevation (LLA, 2009). To renew their license, Appalachian Power Company (Appalachian Power), a unit of American Electric Power (AEP), submitted an application for a new license in March In August 2009, the Federal Energy Regulatory Commission issued a Final Environmental Impact Statement for the Smith Mountain Project relicensing. While reissuing, the Commission reviewed AEP s methods and proposals for the protection, mitigation of damage to, and enhancement of fish and wildlife (including related spawning grounds and habitat), the protection of recreational opportunities, and the preservation of other aspects of environmental 1

11 quality. (FERC, 2009, p. 1). In the final Environmental Impact Statement (EIS), FERC endorsed Appalachian Power s proposed $25,000 annually to the LLA to support the on-going water quality monitoring program (FERC, 2009, p. 25). The Commission approved the new license, effective April 1, FERC recommended a few modifications to Appalachian Power s Water Quality Monitoring Plan including a proposal to develop a lake water quality monitoring plan. FERC determined that the primary water quality issues for Smith Mountain and Leesville lakes arise from nutrients and bacteria. Rather than coming from the dams operations, the nutrients and bacteria come from shoreline development and overall watershed development. In conclusion, FERC recommended the (a) continuation of water-quality monitoring for Smith Mountain Lake, (b) establishment of a water quality monitoring program for Leesville Lake, and (c) ensuring the future health of the lakes by monitoring lake quality to verify that any changes in operational strategy at the Smith Mountain project do not harm water quality. In summary, a timeline of significant events is outlined below: April 1960: First license for Smith Mountain Project issued April 2007: Development of Leesville Lake Citizen Water Quality Monitoring Plan : LLA annually reports on water quality 2008: AEP proposed $25,000 in 2010 to LLA for water quality monitoring plan August 2009: FERC issues a final EIS for Smith Mountain Project relicensing, recommending a water quality plan for Leesville Lake April 2010: AP s new license for Smith Mountain Project becomes effective June 2010: Lynchburg College begins water quality testing of Leesville Lake February 2011: Lynchburg College reports on 2010 water quality February 2012: Lynchburg College reports on 2011 water quality February 2013: Lynchburg College reports on 2012 water quality February 2014: Lynchburg College reports on 2013 water quality February 2015: Lynchburg College reports on 2014 water quality Participants: In August 2003, a group of Leesville Lake residents formed a non-profit 501(c)(3) corporation called the Leesville Lake Association. The association addresses the issues of debris, shoreline management, environmental and biological health, safety, future development, and fishing for Leesville Lake (LLA, 2003). In 2007, the Department of Environmental Quality revised the Millennium 2000 Water Quality Monitoring Strategy. The Virginia DEQ maintains the Water Quality Monitoring and Assessment (WQMA) Program with the ultimate goal to provide representative data that will permit the evaluation, restoration and protection of the quality of the Commonwealth s waters at a level consistent with such multiple uses as prescribed by Federal and State laws (VDEQ, 2007). 2

12 LLA partnered with Lynchburg College to establish the Water Quality Monitoring Plan. Lynchburg College agreed to conduct the samplings and testing, and report results. LLA water monitoring volunteers for 2014 were: Tony Capuco and Mike Lobue. For a description of Leesville Lake and communities, refer to Section 2 of Lynchburg College s report titled Leesville Lake 2010 Water Quality Monitoring dated February 28, Statement of Goals and Objectives (Also stated in the 2010 and 2011 Leesville Lake Water Quality Monitoring Reports): Goals and Objectives of the Leesville Lake Water Quality Monitoring Plan: The Federal Energy Regulatory Commission recommended that a water quality plan for Leesville Lake be developed. In a collaborative approach, Leesville Lake Association and Lynchburg College developed a plan in February 2010 to continue and expand the testing and monitoring of water quality, to monitor nutrients and trophic status, and to supplement data collected by the Virginia Department of Environmental Quality in order to better understand the current state of Leesville Lake. Leesville Lake Association The objectives of the Leesville Lake Association, according to its Articles of Incorporation, are as follows ( Plan projects and studies that: a. Monitor and protect the water quality of Leesville Lake b. Contribute to the clean-up and preservation of the lake s shorelines c. Promote safe recreational use d. Improve the condition of the surrounding land as a high-quality recreational and residential area e. Maintain favorable water levels in Leesville Lake for the Smith Mountain Pumped Storage Hydro Project Educate to individuals, organizations, and the general public information concerning: a. Water quality monitoring results b. Management techniques and practices to preserve the environmental quality of Leesville Lake and its watersheds c. Safe recreational activities d. Commercial and government activities that could harm geographic area of Leesville Lake e. How to maintain optimum water levels in Leesville Lake 3

13 Section 2: Historical Data 2.1 Sources with Summaries of Historical Data The annual reports of the Leesville Lake Association s Citizen Water Monitoring Project and the Virginia DEQ data are the two primary sources of historical data. DEQ compiled the data with the assistance of the Department of Conservation and Recreation (DCR) for its Virginia Water Quality Assessment Reports. Data was collected by the agencies quality control citizen monitoring data. DEQ used Water Quality Management Plans (WQMPs), required by section 303(e) of the Clean Water Act, to establish the link between the required water quality assessment and water quality based controls. Map 2.1. Leesville Lake Water Quality Monitoring Stations with DEQ Identification (Lobue 2011) 4

14 From June through November 2010, Lynchburg College and volunteers from LLA collected Leesville Lake water quality data. Lynchburg College sampled eight sites while LLA sampled seven. Data on water quality parameters included temperature, oxygen (dissolved oxygen and percent saturation dissolved oxygen percentage), conductivity, ph, oxidation-reduction potential, turbidity and more. Lynchburg College and LLA volunteers also monitored water quality in 2011, 2012, 2013 and Total Maximum Daily Load (TMDL): The Virginia Total Maximum Daily Load (TMDL) Program, which addresses waters with bacteria levels exceeding state standards, published a report in 2006 on waters around Leesville Lake. This report addressed bacteria levels flowing from the lake s two main tributaries; Pigg River and Old Woman s Creek (Lobue, 2010, p. 10). Story Creek (a tributary to Leesville Lake- Pigg River) and Upper Pigg River have been on Virginia s 303(d) list of impaired waters since Leesville Lake-Pigg River has been listed as impaired since Snow Creek (another tributary to Leesville Lake-Pigg River) and Old Woman's Creek have been listed as impaired since The TMDL report identified three point sources discharging bacteria into the Pigg River basin, with one located in the Story Creek watershed area. There were no permitted dischargers in the Old Woman's Creek watershed. The TMDL reporting specifies nonpoint sources as the primary source for high bacteria levels; including agriculture, land-applied animal waste, and livestock manure are the main nonpoint sources. The report also specifies that cattle and wildlife directly dumping feces into streams cause a large bacteria load. Nonpoint sources from residential areas include straight pipes, failing septic systems, and pet waste (Virginia Tech, 2006). Map 2.2. Pigg River and Old Womans Creek Watersheds from TMDL studies (Virginia Tech, 2006). 5

15 Map 2.3 Franklin County Virginia showing Pigg River flowing under Smith Mountain Lake and into Leesville Lake along the border of Franklin and Pittsylvania counties. For reference, Snow Creek And Pigg River are shown in greater detail in Map 2.2. Pigg River and Old Woman's Creek TMDL Implementation Plan published 2009 identifies work necessary for E. coli reductions in the watershed to bring violation rates below 10% per year. Majority of the need is controlling pasture runoff with livestock fencing and point source reductions. Of concern for Leesville Lake are the elevated E. coli concentrations in Pigg River discharge. Additionally, cattle are consistently in the creek at the Leesville site. The Leesville community needs to support the work of both the soil and water conservation districts, VADEQ and VADCR as they work toward implementation of the TMDL effort. The community should also be active in controlling residential discharge directly in the lake and efforts to upgrade septic systems in the watershed. 6

16 Section 3: Current Conditions (Year 2014) 3.1 General: This is the fifth year of water quality monitoring by Lynchburg College in partnership with Leesville Lake Association (LLA). Five years of data continue to strengthen our understanding of water quality and allows us to pinpoint areas of concern and management. At the end of this report, trends from these five years of sampling are examined and a more detailed analysis of Pigg River and Smith Mountain Lake Dam operations are examined. The majority of this report documents the current year sampling by Lynchburg College and volunteers. It is reported in tabular form allowing future analysis of the data and in graphical form allowing a visual for emerging trends. This project continues to provide essential baseline results for the condition of the lake. We look forward to the continued study of the lake. 3.2 Methods: Data was collected by Lynchburg College through a series of water samplings and testing from April through October, when lake productivity is high. The following eight sites were sampled, as stated in the Leesville Lake Water Monitoring Plan: Table 3.0. Leesville Lake 2014 Sampling Sites Lynchburg College Station Leesville Lake Association Station Site ID DEQ Station ID Latitude Longitude LVLAROA Leesville Lake Dam Pit Stop LLAOWC Marina Tri County LLATER Marina Mile Marker LLAROA Mile Marker LLAROA Toler Bridge LLAROA Pigg River LLAPGG Smith Mtn. Tail Waters LVLAROA Samples taken at each station on a monthly basis: April 23, May 24, June 25, July 31, August 26, September 26 and October 29. Additional water sampling was provided by volunteers at selected sites on June 17, July 16 and August 13. For more detail concerning water quality testing parameters, quality assurance (QA) and quality control (QC), please see Appendix A, B and C. 7

17 3.3 Water Quality: Current Test Results (2014) Temporal Analysis by Station Background The analysis of results is divided into three distinct zones representing the zones of the reservoir. In the portion near the Leesville Lake dam, we consider the reservoir to be Lacustrine and we have labeled it the Dam site. This classification suggests the reservoir will take on qualities we often see associated with lakes. It is the deepest portion of the reservoir and less likely to be immediately affected by river inputs. It should show the strongest levels of stratification and develop patterns of biology, chemistry and physical processes better understood from lake limnology. However, the lacustrine zone is not isolated from Riverine influences. During high volume storm events stratification is broken down in these areas and the reservoir resembles a river from headwaters to the dam. The middle portions of the reservoir are considered the transition zones. This is Mile Marker 6 (MM6) in our study. In this area, the Lacustrine portions of the reservoir meet the Riverine dominated sections. This area often exhibits the highest areas of productivity due to river inputs of nutrients yet slows water velocities allowing biological processes to flourish. This defined area may move in the reservoir as Riverine processes exert influence. This is again driven by hydrological inputs. In our best analysis, it is acceptable to observe the transition zone based upon depth, nutrient transport and productivity. The upper portions of the reservoir are considered Riverine. This is labeled as Toler Bridge in our study. The reservoir s Riverine Section behaves much like a large river system. While nutrients are often elevated so are the sediment inputs. This limits potential limnetic (open water) biological productivity but often creates ideal conditions for littoral (shoreline) production. Nuisance rooted vegetation often takes hold in this portion of the reservoir. Inputs from Riverine areas often determine water quality parameters for the Lacustrine portions. Additionally, several sites throughout the reservoir were sampled for specific reasons. We sampled marinas at the lake (Pitt Stop and Tri County) due to concern of possible E. coli contamination. We sampled Mile Marker 9 to study a point above the transition zone as the lake becomes riverine. We sampled Pigg River confluence to determine the potential impacts this river has on water quality in the lake. Finally, we sampled Smith Mountain Lake tail waters to see water quality entering from the lake. The following analysis divides the reservoir into these three sections and then discusses the additional sampling stations on expected and observed results. One of the difficulties for predicting water quality trends in Leesville Lake is the artificially influenced hydrology. While expectations are outlined, Smith Mountain Lake operations are a dominant hydrological feature and create difficulty in predicting the water quality of Leesville Lake. 8

18 3.3.2 Dam (Lacustrine) The area near the Leesville Lake dam is considered a Lacustrine section. It exhibits characteristics similar to a lake and can be analyzed for similarities to lake conditions. Conductivity Conductivity (us/cm) Depth (m) April May June July August Sept Oct Figure 3.1. Dam (Lacustrine) Conductivity (µs/cm) measures over study period (2014). Conductivity (Figure 3.1) measures in reservoirs often show us changes in hydrology. In 2014 we observed patterns similar to previous years. Small changes in conductivity throughout the sampling season but patterns are generally stable throughout the water column. Table 3.1. Dam (Lacustrine) Conductivity (µs/cm) Measures Over Study Period (2014). Depth (m): 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

19 Dissolved Oxygen Dissolved Oxygen (Figure 3.2) profiles continue to reinforce the idea that the Leesville Lake is a eutrophic reservoir. A general pattern has emerged. In the epilimnion (upper 2 meters) the water is well oxygenated and stable. In the metalimnion (2-6 meters) transition occurs. Oxygen may increase showing a positive heterograde or decrease begining a negative heterograde. Into the hypolimnion, oxygen continues to decrease through all depths of measure. Depending on time of year and strength of stratification, the loss of oxygen may be greater. Observe the strong contrast between April and July. Starting at similar concentrations of oxygen at the surface, in July the loss of oxygen with depth is pronounced. In the months (May and June) showing a positive heterograde (oxygen increase in the metalimnion), corresponding we observed peaks of Chlorophyll a in the same areas. Conditions in the reservoir are capable of producing these high concentration blooms of phytoplankton. This pattern is typical of eutrophic reservoirs and is a repeatable event in Leesville Lake. Interestingly and similar to the 2012 and 2013 test results, a strong pattern of oxygen loss occurs in early fall. This is a typical pattern for reservoirs in this area and greatly restricts quality habitat for fisheries. This pattern did not set up until late in the sampling year (August) due to high rates of rainfall throughout the spring and early summer. 10

20 Dissolved Oxygen (mg/l) Depth (m) April May June July August Sept Oct Figure Dam (Lacustrine) Dissolved Oxygen (mg/l) measures over study period (2014). These data will be looked at in conjunction with Temperature (Figure 3.3). Table 3.2. Dam (Lacustrine) Dissolved Oxygen (mg/l) Measures Over Study Period (2014). Depth (m): 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

21 Temperature Inconsistent with past observations, the warmest months did not exhibit the greatest degree of stratification. In 2014, May and June were months with the greatest degree of stratification (Figure 3.3). Interesting, this set conditions in the lake producing the pattern of positive heterograde and high peaks of Chlorophyll a in the metalimnion. After June stratification, remaining summer samples suggest the lake entered a polymictic phase alternatively mixing and stratifying. Hydrology is the only explanation for this pattern. Analyzing oxygen and temperature data together supports the idea that the reservoir is eutrophic. Interestingly, weak or no stratification in temperature support much stronger patterns of oxygen loss in the hypolimnion. This is again supported by the 2014 data. With weaker stratification, oxygen loss is greater (Figure 3.2). The pattern of polymictic (mixing many times throughout the year) behavior in the reservoir is suggested by the data. This behavior seems to have two observable results. First, it breaks up the blooms of phytoplankton occurring in the metalimnion. The mixing distributes these organisms throughout the water column. Secondly, the breakdown of these mixed phytoplankton (many perish as light is diminished at greater depth) depletes oxygen throughout the hypolimnion. While this is a pattern we now see on the reservoir, the driving mechanism for this polymictic behavior is still unclear. Because flooding of the reservoir is a stochastic event (un-predictable) data does not support storm flow creating a consistent summertime mixing of the reservoir. SML dam operations (a deterministic event) seems more plausible explanation of the mid-summer mixing. 12

22 Temperature (C) Depth (m) April May June July August Sept Oct Figure 3.3. Dam (Lacustrine) Temperature (Degrees C) measures over study period (2014). Table 3.3. Dam (Lacustrine) Temperature (Degrees C) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

23 Chlorophyll a The depth and seasonal content of chlorophyll a in the water (Figure 3.4) illustrates the productivity patterns in the reservoir. Similar to the pattern observed in previous years, high concentrations of chlorophyll a were observed in the metalimnion (transition zone between the epilimnion and the hypolimnion). Using all of the data collected, we can speculate on the stratification layers of the lake. The epilimnion is from the surface to 3 meters. The metalimnion occurs between 3-6 meters and the hypolimnion from 6 meters and below. Phytoplankton will collect and grow to highest concentrations in the metalimnion. Now with an additional year of collected data this pattern continues to occur and we believe it is a reliable summer condition in the lake. The metalimnion provides mixing, greater supplies of nutrients and good supplies of light energy for photosynthesis. Observable in 2014 is the break up of this pattern in August. It is unclear how the bloom of phytoplankton that appeared in the metalimnion throughout May, June and July would behave if stratification remained strong in the reservoir. Polymictic behavior reduced metalimnetic blooms of phytoplankton throughout the summer in Based on the parameters of trophic state for lakes and reservoirs (Table 3.4), the blooms of phytoplankton in the metalimnion are suggestive of a eutrophic lake. Additionally, concentrations of total phosphorus (Table 3.9) fluctuate between various levels of eutrophic condition. The pattern is difficult to discern at times due to the changes in hydrology. Table 3.4. Typical trophic state indicators for lakes 1. Organic TP mg/l Avg Chl a Secchi Depth TSI Matter (ppb) (M) Oligotrophic low < 40 Mesotrophic medium Eutrophic high Hypertrophic very high > 70 1 TP = Total Phosphorus, TSI = Trophic State Index Additionally, the very high concentrations of phytoplankton in the metalimnion continue to be a concern. When we integrate the observations throughout the water column (Table 3.9) we see a reservoir that is only slightly eutrophic. However, looking at point specific data in the 14

24 metalimnion, the reservoir is very eutrophic. Management recommendations are suggested concerning this issue. It is also important to note that Secchi depth may not be an adequate predictor of the trophic status in Leesville Lake. Typically Secchi depth provides a better trophic state index (TSI) than total phosphorus (TP) and Chlorophyll a data provide. This study s Secchi depth measures go to depths of 3 meters. Although this is a positive measure of water quality, the data suggest much of the algal turbidity is below the recorded Secchi depths and that the good water clarity through 3 meters supports this concentration of phytoplankton growth in the metalimnion (2-6 meters). Chlorophyll a (ug/l) Depth (m) April May June July August Sept Oct 14 Figure 3.4. Dam (Lacustrine) Chlorophyll a (ppb) concentrations over study period (2014). Table 3.5. Dam (Lacustrine) Chlorophyll a (ppb) concentrations over study period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

25 ph The ph (Figure 3.5) of water is reflective of phytoplankton and chemical activity. We see elevated ph during times and in the profiles during high phytoplankton activity. Elevated ph occurs from phytoplankton productivity removing CO 2 from water. Carbon dioxide acts as a weak acid in water and its removal elevates ph ph data provided an interesting pattern, with July ph readings being very elevated in correspondence with high concentrations of Chlorophyll a. These readings were elevated throughout the epilimnion suggesting some periods of stratification. The ph readings of up to 9 are very concerning as this approaches levels of hyper-eutrophy. Again, the breakup of stratification pattern and lower levels of Chlorophyll a into August prevented are suggested as the mechanism that prevented hyper-eutrophic conditions from developing in the reservoir. Additionally, we did not see the very low ph levels observed in the hypolimnion that we observed in Typically, ph levels drop throughout the hypolimnion as photosynthesis declines. Patterns observed in 2014 were typical and expected based on other observations, whereas the low ph observed in the hypolimnion in 2013 remains unexplained. 16

26 ph Depth (m) April May June July August Sept Oct Figure 3.5. Dam (Lacustrine) ph measures over study period (2014). Table 3.6. Dam (Lacustrine) ph Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

27 ORP Oxidation Reduction Potential (ORP) measured in Figure 3.6 provides information related to chemical transformations in the reservoirs and can identify anaerobiosis in the water column. Patterns for this measure support observations from the other measurements in the lake. The pattern in the reservoir shows an increasing ORP level throughout the season with the exception of June observations. In general, waters are oxidized throughout the sampling season and this governs the chemistries we observe. ORP values suggest that the lake has an oxidizing environment. In practical terms, a reduced environment forces many species of bacteria to use carbon or sulfur as the energy metabolizing element and thus byproducts from this produce rather unpleasant odors such as rotten egg smell. Also, this type of metabolism is less efficient than the use of oxygen in the oxidized environment the lake is producing. ORP Depth (m) April May June July August Sept Oct Figure 3.6. Dam (Lacustrine) ORP (mv) measures over study period (2014). 18

28 Table 3.7. Dam (Lacustrine) ORP Measures (mv) Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct Turbidity Turbidity (Figure 3.7) is influenced by the combination of both phytoplankton growth and sediment entering the reservoir. At the dam site, we expect the entry of sediment to be minimal and turbidity to reflect the phytoplankton content of the water. That phytoplankton is the primary driver of turbidity in this portion of the lake is borne out by the direct relationship between chlorophyll a and turbidity. The highest productivity months of May-August showed an increased turbidity below 2 meters. And in contrast to 2013, turbidity did provide a good measure of Chlorophyll a at this site. I can conclude Dam site is driven by nutrient phytoplankton productivity, with minimal impact from sediment during average rainfall years. 19

29 Turbidity (NTU) Depth (m) April May June July August Sept Oct Figure 3.7. Dam (Lacustrine) Turbidity (NTU) measures over study period (2014). Table 3.8. Dam (Lacustrine) Turbidity (NTU) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

30 Other Measured Parameters Looking at the other parameters (Table 3.9) we gain insights into the integration of biology and chemistry operating within the reservoir. The Trophic State Index (TSI) is a good indicator of lake condition (Table 3.9). Leesville Lake is still in very good condition with average TSI values just slightly eutrophic (50-70 range for eutrophic conditions). Again in 2014, TP gave the strongest indication of eutrophication rather than Secchi depth or Chlorophyll a (Chl a). Additional collections by the volunteers between sampling events supported this observation. With the exception of the July sample, all TSI readings remained ~ 60. However, there is some reason for concern as over time other parameters beyond TP (Chlorophyll a and Secchi depth) may increase as well. It is good to note that Daphnia populations remained in our samples throughout the season although populations remain low. This is now a consistent result and suggests grazing by zooplankton may in effect lower observed Chlorophyll and Secchi observations. This season, we took one sampling during the evening. While chemistries were unaffected, we did observe Leptodora in the samples. Leptodora is a predacious zooplankter eating primarily Daphnia, Ceriodaphnia and Bosmina. Additionally, Daphnia observed this year had long spines and helmets suggesting heavy predation by Leptodora. Leptodora is a strong vertical migrating species as it is very vulnerable to fish predation. If Daphnia continue to help maintain good water quality (I suggest measurable through comparisons of TP-Chlorophyll-Secchi depth) management of Leptodora populations is important. E. coli at this station was very low and similar to past years data. High concentrations of E. coli are not expected in this portion of the lake. Blue-green algae, as measured by phaeophytin florescence, is also presented in Table 3.9 for reference. Table 3.9. Other Parameters measured over study period (2014). Zooplankton numbers are organisms per liter. 24- Apr 23- May 17- Jun 25-Jun 16-Jul 31- Jul 13- Aug 26- Aug 26- Sep 29-Oct Time 10:40 AM 10:20 AM 8:30 AM 10:30 AM 8:30 AM 4:05 PM 9:25 AM 9:25 AM 10:17 AM 10:30 AM Secchi (M) TP at Surface (PPM) TP at 7 Meter (PPM)

31 Integrate Chlorophyll a (PPB) TSI S TSI TP TSI CHL TSI AVG Daphnia Bosmina Diaptomus Cyclops Nauplii Cerodaphnia Diaphanoso ma Chydorus E. coli cfu/100ml BG Algae Cells/ml Mile Marker 6 (Transition) Background In discussing water quality at the transition station (MM6), comparisons are made back to Lacustrine and Riverine. The purpose of this section is not to further discuss the patterns observed at the Dam or Toler Bridge but to discern any trends the data provide on a spatial scale moving up or down the lake. Conductivity Conductivity (Figure 3.8) showed similar trends to the dam station. As in previous years conductivity is relatively stable. 22

32 Conductivity (us/cm) Depth (m) April May June July August Sept Oct 8 10 Figure 3.8. Mile Marker 6 (Transition) Conductivity (µs/cm) measures over study period (2014). Table Mile Marker 6 (Transition) Conductivity (µs/cm) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

33 Dissolved Oxygen The 2014, dissolved oxygen (Figure 3.9) sampling at the transition station did not show a strong stratified pattern compared to the dam. While the dam station shows a positive heterograde we do not see this at this site. This is where we begin to see the influence of hydrology with the movement of water from SML and then pump-back into SML. This station is in the larger portion of the reservoir but does not exhibit strong patterns of limnology. Dissolved Oxygen (mg/l) Depth (m) April May June July August Sept Oct 8 10 Figure 3.9. Mile Marker 6 (Transition) Dissolved Oxygen (mg/l) measures over study period (2014). 24

34 Table Mile Marker 6 (Transition) Dissolved Oxygen (mg/l) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct Temperature Temperature data (Figure 3.10) shows some stratification but surprisingly less than expected in a reservoir and through comparisons with the Dam. During July, when there is temperature stratification at the Dam there is none at MM6. Again, this is good evidence that SML operations are impacting the limnology of the reservoir at this transition station. 25

35 Temperature (C) Depth (m) April May June July August Sept Oct 8 10 Figure Mile Marker 6 (Transition) Temperature (Degrees C) measures over study period (2014). Table Mile Marker 6 (Transition) Temperature (Degrees C) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

36 Chlorophyll a Chlorophyll a (Figure 3.11) exhibited a pattern similar to that at the dam where increased concentrations developed in the metalimnion. Several patterns are important to note at this station. Chlorophyll a peaks are much higher in the water column. Peaks occur around 2 meters in depth here where peaks at the Dam site occur at 4 meters depth (Figure 3.4). Additionally, because of the weak or non-existent stratification these patterns are not as well developed. Peak concentrations are lower than at the Dam station (as well as integrated concentrations). This pattern is impacted by hydrology. Chlorophyll a (ug/l) Depth (m) April May June July August Sept Oct 10 Figure Mile Marker 6 (Transition) Chlorophyll a (ppb) measures over study period (2014). 27

37 Table Mile Marker 6 (Transition) Chlorophyll a (ppb) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct ph The ph measures (Figure 3.12) were elevated in response to phytoplankton productivity. Elevated conditions were similar to 2012 (unlike 2013) with a peak of 8.4 in June. This suggests that the influence of SML on hydrology is more pronounced in seasons with less rainfall and storm water influence. 28

38 ph Depth (m) April May June July August Sept Oct 8 10 Figure Mile Marker 6 (Transition) ph measures over study period (2014). Table Mile Marker 6 (Transition) ph Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

39 ORP ORP measures (Figure 3.13) were similar in analysis to the dam site. ORP Depth (m) April May June July August Sept Oct 8 10 Figure Mile Marker 6 (Transition) ORP measures over study period (2014). Table Mile Marker 6 (Transition) ORP Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

40 Turbidity Turbidity at this site further strengthens the conclusion that hydrology due to SML activity exerts a strong influence on Leesville Lake. Turbidity at the Dam corresponded well with Chlorophyll a measures (see Chlorophyll a and turbidity sections under Dam analysis). Here, turbidity does not mimic Chlorophyll a well. Chlorophyll a peaked at 2 meters here but turbidity at 2 meters was elevated only in June. Remaining elevated conditions occur at greater depth and at higher levels (this suggests sediment inputs played a significantly impacted turbidity, as Chlorophyll a was lower at this station than at the Dam). Additionally, warmer and turbid water (likely from the Pigg River?) flowed through the hypolimnion at MM6. This would explain the minimal stratification observed and the higher turbidity concentrations, when compared to the dam station. It also implicates a significant impact of SML operation in this portion of the reservoir. Turbidity (NTU) Depth (m) April May June July August Sept Oct 8 10 Figure Mile Marker 6 (Transition) Turbidity (NTU) measures over study period (2014). 31

41 Table Mile Marker 6 (Transition) Turbidity (NTU) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct Other Parameters Other parameters (Table 3.17) show similar general trends to those observed at the dam station (Table 3.9) with the following exceptions: 1. Secchi depths are reduced, producing TSI readings above 50 vs. below 50 for Dam. 2. Integrated Chlorophyll a is slightly higher. This may be an anomaly of reduced stratification and greater concentrations throughout the water column. 3. Turbidity is greater at MM6 than at the dam, again suggesting influence of hydrology. 4. E. coli very similar to the dam, but elevated at times. Again, suggesting hydrology influence. 5. Overall population concentrations of zooplankton are lower. The increased phytoplankton productivity at this site may be a result of lower zooplankton grazing. Spatial patterns of fish planktivory are difficult to predict but the upper reaches of the reservoir are likely to contain greater concentrations of planktivorous fish. If this is occurring, grazing control of phytoplankton may be very important. 6. Elevated TSI. It clearly trended higher with all measures suggestive of a eutrophic reservoir. This site is typically more productive. Why it is more productive may be a combination of position (transition area of reservoir) and operations (SML dam). 32

42 Table Mile Marker 6 (Transition) Other Parameters measured over study period (2014). 24- Apr 23- May 17- Jun 25- Jun 16-Jul 31-Jul 13- Aug 26-Aug 26-Sep 29-Oct Time 11:37 AM 11:15 AM 9:05 AM 11:43 AM 9:00 AM 9:58 AM 10:25 am 11:13 AM 11:24 am Secchi (M) TP Surface (PPM) TP 7 Meters (PPM) Integrate Chl a (PPB) TSI S TSI TP TSI CHL TSI AVG Daphnia Bosmina Diaptomus Cyclops Nauplii Cerodaphnia Diaphanosoma Chydorus E. coli cfu/100ml BG Algae Cells/ml Toler Bridge (Riverine) Background The station at Toler Bridge is influenced heavily by Riverine conditions and the tail waters of Smith Mountain Lake. We would expect the Pigg River to deliver nutrients and sediment with tail water discharge influencing the hydrology and the water quality. Conductivity Conductivity (Figure 3.15) here is higher than at other stations down lake. This suggests the influence of river and SML inputs. This is likely a result of both the Pigg River and the tail 33

43 waters, with a greater influence from tail water discharge, due to water volume, flow rate and frequency of elevated flows. These results are consistent with all previous sampling years on the lake. Conductivity (us/cm) Depth (m) April May June July August Sept Oct 4 5 Figure Toler Bridge (Riverine) Conductivity (µs/cm) measures over study period (2014). Table Toler Bridge (Riverine) Conductivity (µs/cm) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

44 Dissolved Oxygen Dissolved oxygen measures (Figure 3.16) show that stratification is minimal at this station. A warm surface layer that may be created is immediately dissipated by rapidly flowing movements of water both to and from SML. Temperature measures (Figure 3.17) support this conclusion as well. This station is completely driven by SML and Pigg River mix. Dissolved Oxygen (mg/l) Depth (m) April May June July August Sept Oct 4 5 Figure Toler Bridge (Riverine) Dissolved Oxygen (mg/l) measures over study period (2014). Table Toler Bridge (Riverine) Dissolved Oxygen (mg/l) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

45 Temperature Again as in past years, in 2014 July water temperature was relatively cool. This suggests frequent movement of water in this area between the SML and Leesville Lake. Temperature (C) Depth (m) April May June July August Sept Oct 4 5 Figure Toler Bridge (Riverine) Temperature (Degrees C) measures over study period (2014). 36

46 Table Toler Bridge (Riverine) Temperature (Degrees C) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct Chlorophyll a Chlorophyll a concentrations at this station appear influenced by SML operations as evidenced in Figure (3.18). It is difficult to draw conclusions based on limnology of the reservoir without clear knowledge of hypolimnetic flow from SML. Patterns do emerge in May when it appears SML release is considerably less than during the summer months. During May, concentrations of chlorophyll a are the highest observed at this station. Pattern is quite different than the remainder of the reservoir and strongly suggestive of SML operations. At times, very little Chlorophyll a is observed. 37

47 Chlorophyll a (ug/l) Depth (m) April May June July August Sept Oct 4 5 Figure Toler Bridge (Riverine) Fluorescence measured Chlorophyll a (ppb) measures over study period (2014). Table Toler Bridge (Riverine) Fluorometer measured Chlorophyll a (ppb) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

48 Toler Bridge ph trends (Figure 3.19) do not show tends that reflect correlation with primary productivity. Arguably more reflective of Pigg River (Table 3.33) or hypolimnion of SML. ph Depth (m) April May June July August Sept Oct 5 Figure Toler Bridge (Riverine) ph measures over study period (2014). Table Toler Bridge (Riverine) ph Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

49 ORP Depth (m) April May June July August Sept Oct 5 Figure ORP measures over study period (2014). All ORP (Figure 3.20) are within the oxidized range and in a much tighter range of measures. Table Toler Bridge (Riverine) ORP Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

50 Turbidity (NTU) Depth (m) April May June July August Sept Oct 5 Figure Toler Bridge (Riverine) Turbidity (NTU) measures over study period (2014). Turbidity observations at Toler Bridge provide a very different view and interpretation of the reservoir. At the other stations, turbidity values increased with depth. Largely due to phytoplankton productivity. Here, turbidity values decline with depth. This strongly demonstrates that warmer Pigg River water with higher turbidity enters at this station over top of cooler and less turbid hypolimnion release from SML. It the pattern of mixing that is created by the movement of water back and forth in this area remains unclear. However, based on these measures it appears that Pigg River water still flows above water from SML release. But also inferred from this data is the higher turbidity values at depth, relative to those elsewhere in the lake, suggesting that the SML release at Toler Bridge is still mixed with that water from the Pigg River to some degree (based on logic hypolimnion release from SML is very low in turbidity). Table Toler Bridge (Riverine) Turbidity (NTU) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

51 Other Parameters Other parameters (Table 3.25) provide a very interesting picture of the reservoir. TSI measures are generally lower with respect to other portions of the reservoir. TP measures remain high but Secchi Depth is very similar to that observed at the Dam and Chlorophyll a is much lower. The mixing and hydrology of SML is very influential in these trends. The continued mixing and movement of the water keeps TSI low relative to Chlorophyll a and Secchi depth while TP TSI remains elevated as expected at this site. Interpretation of zooplankton is difficult, as I believe water movement is strongly impacts these populations. Daphnia is present and variable in population density. And at times E. coli is elevated, but this too is very dependent on hydrology. Table Toler Bridge (Riverine) Other Parameters Measured Over Study Period (2014). 24- Apr 23- May 17- Jun 25- Jun 16-Jul 31- Jul 13-Aug 26- Aug 26- Sep 29- Oct Time 12:17 pm 11:52 am 9:25 AM 12:27 pm 9:15 AM 6:05p m 10:25 AM 11:05 pm 11:52 am 12:07 pm A B Secchi (M) TP Surface (PPM) TP 7 Meters (PPM) NO Integrate Chl a (PPB) TSI S TSI TP TSI CHL TSI AVG Daphnia Bosmina Diaptomus Cyclops Nauplii Cerodaphnia Diaphanosoma Chydorus E. coli

52 cfu/100ml BG Algae Cells/ml Other Data The two marina sites were evaluated for Secchi depth, E. coli and TP to determine possible contamination from septic systems and possible changes in clarity. Neither site demonstrated data to support the possibility of contamination and fit general trends throughout the lake. Table Pit Stop Marina Other Parameters Measured Over Study Period (2014). Table Tri County Marina Other Parameters Measured Over Study Period (2014). 24-Apr 23- May 17-Jun 25-Jun 16-Jul 31-Jul 13-Aug 26-Aug 26-Sep 29-Oct time 11:22 PM 11:00 AM 8:12 AM 11:23 AM 8:12 AM 5:00 PM 9:15 AM 10:05 AM 10:55 AM 11:03 AM Secchi TP A B E. coli, cfu/100ml Cells/ml Apr 23- May 17- Jun 25-Jun 16- Jul 31-Jul 13- Aug 26- Aug 26- Sep 29-Oct 11:30 11:08 8:50 11:32 8:43 9:48 10:15 11:03 11:16 time AM AM AM AM AM AM AM AM AM Secchi TP A B E. coli, cfu/100ml Cells/ml

53 Two additional sites were analyzed for TP concentrations (data not shown). These data provide good reference of spatial trends throughout the lake. At this time no further analysis is conducted. 44

54 Table Mile Marker 9 Other Parameters Measured Over Study Period (2014). 24-Apr 23-May 17-Jun 25-Jun 16-Jul 31-Jul 13-Aug 26-Aug 26-Sep 29- Oct 12:06 11:42 9:15 12:12 9:10 10:10 10:55 11:42 time PM AM AM PM AM AM AM AM 11:56 Secchi TP A B E. coli, cfu/100ml Cells/ml Table Smith Mountain Lake Tail Waters Other Parameters measured over study period (2014). 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct 12:57 12:31 11:45 12:25 12:41 1:00 PM Time PM AM AM PM PM Temp Cond DO ph % ORP Turb Secchi, m TP Sfc E. coli, cfu/100ml A B Cells/ml Data for tail water release at bridge helps to quantify what is released into Leesville Lake. Concerns over low oxygen release in the summer months along with influence from Pigg River during drawback are of concern. All data collected as part of this study do not suggest any concerns from low dissolved oxygen during We do see E. coli and it is believed the only source of this is from Pigg River during draw back operations. The concentrations are much higher in fall than spring. TP is highly variable again influenced by hydrology. 45

55 Pigg River site again demonstrated high inputs of phosphorus, E. coli and poor water quality entering the lake (Table 3.31). Under low flow conditions water from dam operations may flow into this site giving diluted readings. It is clear from our study that the Pigg River is contaminated. The Pigg River has exceeded Virginia standards for E. coli on numerous occasions. During volunteer samples on August 13, 2014 the river was in violation. This river consistently delivers high concentrations of TP and sediment to Leesville Lake. Table Pigg River Other Parameters Measured Over Study Period (2014). Table Pigg River Dissolved Oxygen (mg/l) Measures Over Study Period (2014). 24-Apr Jun 16-Jul 31-Jul May Jun Aug Aug 26-Sep 29-Oct Time 12:39 PM 12:15 PM 9:35 AM 12:48 PM 9:20 AM 7:38 PM 10:3 5 AM 11:30 AM 12:08 PM 12:27 PM A B Secchi (M) TP Surface (PPM) TSI S TSI TP TSI AVG E. coli cfu/100ml BG Algae Cells/ml Depth: 24- Apr 23- May 25- Jun 31-Jul 26- Aug 26- Sep 29- Oct Table Pigg River Temperature (Degrees C) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct Table Pigg River ph Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct

56 Table Pigg River Conductivity (mg/l) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct Table Pigg River Turbidity (NTU) Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct Table Pigg River ORP Measures Over Study Period (2014). Depth: 24-Apr 23-May 25-Jun 31-Jul 26-Aug 26-Sep 29-Oct Section 4: Lake-wide Trending The purpose of this section is to look at the functioning of the reservoir and establish trends. These trends are important to give a trajectory of lake health and allow us to manage the lake for optimum water quality. These trends are based on collected water quality parameters over the course of this study and compilation into trophic state indices and other predictive indicators. The use of these indices allows ease of comparison among known parameters for lake and reservoir function translating raw data into a useable management tool. As with any index, we have room for interpretation and alternative explanations of hypotheses. However, within the science of limnology (study of lakes), use of the indices is widespread and offers good explanations. 4.1 Analysis of Trophic State In this analysis, trending of all the measurable trophic state indices (TSI) are looked at over a four year period. The usefulness of this is many-fold. First, we can examine many different parameters that are used to predict TSI or lake health. The use of multiple parameters always 47

57 strengthens any scientific investigation. Second, each parameter measured provides a predictor based on differing influences within the reservoir. Secchi depth is influenced by both sediment input and phytoplankton growth whereas total phosphorus (TP) simply reflects the concentrations of this limiting nutrient. Additionally, chlorophyll a concentrations reflect use of TP for phytoplankton growth within the limitations of shading (sediment inputs) and grazing by zooplankton (Daphnia concentrations). While each TSI predictor provides a differing parameter for prediction, often the predictions are within similar ranges. Secchi Depth TSI Dam MM6 Toler Bridge Figure Trophic State Index (TSI) based upon Secchi disk measurements in Leesville Lake from Y axis reflects the calculated TSI for each of the three primary sampling stations throughout the reservoir. The shaded box represents the mesotrophic range for TSI where below this range is oligotrophic conditions and above represents eutrophic conditions. Analysis: Secchi depth remains in the slightly eutrophic range for the portions of the lake from MM6 and above. Trends at the dam are encouraging as these readings remain in the mesotrophic range and continue to trend downward. As 2013 was a relatively wet year, Secchi depth TSI correspondingly was elevated. The lake shows good resilience as 2014 levels returned to historical means. Interestingly, Toler Bridge TSI was equal to MM6. This is not typical as a reservoir often shows a gradient from headwaters to the dam in TSI. This trend will be discussed in subsequent sections. 48

58 Total Phosphorus TSI Dam MM6 Toler Bridge Figure Same as Figure 4.1 but for Total Phosphorus (TP). TSI based on TP remained at eutrophic levels in The 2013 upward trend returned to historic levels. While TP concentrations put the reservoir in the eutrophic range, it is not generating observable problems. Interestingly, in 2014 the station at Toler Bridge TP concentration equaled the remainder of the lake. This is unexpected as the upper stations of the lake are typically more eutrophic (compare analysis of SML from top to bottom). This is an interesting result again discussed in subsequent sections. Total phosphorus trends have a strong influence on water quality in reservoirs and must be controlled to maintain good water quality. 49

59 Chlorophyll a TSI Dam MM6 Toler Bridge Figure Same as Figure 4.1 but for Chlorophyll a. Chlorophyll a (Chl a) is the measure of the photosynthetic pigment found in all plant cells. Its measure gives us a direct correlation to the concentration of phytoplankton in the reservoir. This measure is a reflection of how TP is utilized by phytoplankton. Overall concentrations of zooplankton grazing on phytoplankton, hydrological movements of water flushing phytoplankton out of the reservoir and into the river and sediment inputs shading the amount of light available to phytoplankton and lower the TSI. In Leesville Lake, Chl a TSI measures were higher than both TP and Secchi depth with the exception of Toler Bridge Station. This suggests processes such as grazing influence the populations of phytoplankton at Dam and MM6 while the flushing and mixing of water at Toler Bridge controls phytoplankton. The artificial hydrology created by SML dam operations may have a strong influence on this result particularly in the low concentrations observed at Toler Bridge and higher concentrations at MM6 and Dam. It is interesting to note that this trend is decreasing into the sample years of This is perhaps a result of changes in operations of SML. 50

60 TSI Average Dam MM6 Toler Bridge Figure Same as Figure 4.1 but for TSI average Results. Looking at average TSI demonstrates that Leesville Lake is a mildly eutrophic reservoir and relatively stable in this classification. Results are very consistently within the range. These TSI values are roughly 10 points higher than averages observed in Smith Mountain Lake, which shows fluctuations of water quality in the range. And for the first time in this study Toler Bridge TSI is lower than other parts of the reservoir. This suggests that the hydrology generated by SML is changing or variable. Also, environmental programs to improve the health of the Pigg River is exerting an influence as well. 51

61 Daphnia Dam MM6 Toler Bridge Figure Same as Figure 4.1 but for Daphnia analysis. Numbers on y axis represent Daphnia / liter. Daphnia trends over the study period show relatively low concentrations for this species. Daphnia can exhibit strong grazing pressure on phytoplankton and this is often reflected in lower chlorophyll a concentration per TP concentration in a reservoir. Moving into 2014, we observed lowering abundances from 2013 and earlier in the areas of the main lake but increasing at Toler Bridge station. Interestingly with the improved TSI at Toler Daphnia populations increased. This may be a causative correlation, but we do not have sufficient data to draw this conclusion. This trend may be driven primarily by hydrology discussed throughout this report. 4.2 Limnology of Leesville Lake Limnology refers to the biological and ecological function of the lake. Here, I am analyzing a reservoir, so typical limnological paradigms may not hold true. Nevertheless, within this context we want to understand several key parameters, as they each hold the key to management of the reservoir. Theoretically in lake limnology spring time concentrations of total phosphorus (TP) set the concentrations of phytoplankton productivity (measured as Chlorophyll a). This is why we 52

62 traditionally measure these parameters and weigh heavily upon them in our analysis. Further research suggests that this understanding does not include the impact of grazing on phytoplankton productivity and thus a measure of zooplankton populations in the lake can be informative about the roles these organisms have in regulating water quality. Of all species of zooplankton found in the reservoir, only species of Daphnia have the population density and filtering capacity to graze phytoplankton faster than growth rates phytoplankton have. Further, because this is a reservoir, non-algal turbidity such as suspended clay particles influence the light entering the reservoir and can inhibit the growth of phytoplankton. And even further in the instance of Leesville Lake (LL) Smith Mountain Lake (SML) Complex, the washing machine effect of water withdrawal and release brings polluted Pigg River water into SML mixing it with oligotrophic/mesotrophic water before re-release. Additionally, high release of SML pushes Pigg River water rapidly down the reservoir but the problematic impacts of this are mitigated by the hypolimnetic release from SML. Further analysis of SML-Pigg River impacts on Leesville Lake is contained in Section 4.3. We can now examine three relationships to determine if predictability of water quality is possible from traditional limnological analysis. The first relationship is TP-Chl a (Figure 4.6) is a traditional predictor used throughout the world. This relationship is not significant in Leesville Lake suggesting multiple other factors control Chlorophyll a in the reservoir. This relationship will be studied further in the ensuing years R² = Figure Relationship between Chlorophyll a and TP for the last two years of study Y axis reflects all Chl a measures and x-axis reflects all TP measures during this period of time (all units ug/l). The strength of relationship is shown as R 2. Relationship is not significant. 53

63 4.3 Analysis of Relationship Between Pigg River and Smith Mountain Lake Operation on Water Quality The relationship between the Pigg River input and SML operations appears to significantly impact the water quality of Leesville Lake. During this season, several analyses were undertaken to further understand this relationship. I report here continued analysis from the 2013 season and additional analysis to make several conclusions about this relationship. Management implications are reported in Section 5. Water Quality of Pigg River It is understood that water quality of the Pigg River is impaired (DEQ and EPA TMDL analysis for E. coli). During times of positive flow from the Pigg River into the lake (pump back operation draw Pigg River Water into the lake as well as during high flow conditions), E. coli and TP concentrations in the Pigg River are elevated. Considering quality of the river s water and flow rate, this represents the greatest negative impact to Leesvile Lake s water quality. Also consider the following event appearing in Roanoke Times April ; Cow manure taints river in Franklin County Posted: Friday, April 4, :38 pm Roanoke Times People are being warned not to use the water in the Pigg River in Franklin County after about 30,000 gallons of cow manure wastewater spilled into the water on Thursday. The spill occurred at a holding lagoon near the intersection of Calico Rock Road and 6 Mile Post Road, west of Rocky Mount, according to a news release from the Virginia Department of Health. Some of the spill entered a small, unnamed tributary of the Pigg River, upstream from the Waid Park Recreation Area, off 6 Mile Post Road in Franklin County. The release said signs have been posted along the Pigg River at the Waid Park area to advise people to avoid recreational use of the water, including swimming, fishing and wading, until further notice. While there is no indication that this spill poses any increased risk to drinking water, it s important to note that any surface waters may contain organisms that cause disease, Dr. 54

64 Margaret O Dell, the acting director of West Piedmont Health District, said in the release. Anytime you go swimming, boating, fishing or wading, you should avoid drinking or swallowing any water from an unknown or unapproved source, and afterward thoroughly wash any area exposed to these waters. Officials emphasized that any potential risk from this spill would be from coming into contact with or swallowing the water, not from eating properly prepared fish, but signs recommend people avoid fishing in the waters. Officials from VDH s Franklin County Health Department, the Virginia Department of Environmental Quality and Franklin County Parks and Recreation are working to evaluate the spill and minimize any potential risk. manure-taints-river-in-franklin-county/article_c9305e88-bc73-11e3-b6dc-0017a43b2370.html?mode Thus a reasonable conclusion concerning the Pigg River is that impaired water enters the lake on a continued basis and in even greater quantities during storm events. Previous analysis (Leesville Lake Water Quality Report 2013) presented evidence suggesting nutrient loading to the reservoir during times of high E. coli and turbidity. Additionally, hazards (such as manure spills) exist in the watershed and pose even greater risks to water quality. It must be a concern to the residents of Leesville Lake and additionally to the operation of SML. Water Quality of Smith Mountain Lake Trophic State Index (TSI) of SML averaged over a 26 year period (Ferrum College and SML Association Data) suggest the headwaters of SML are eutrophic with TSI values of 60 and mimimally mesotrophic/oligotrophic with TSI values of 40 near the dam. Scientific conclusions then suggest water quality in this portion of SML that feeds Leesville Lake is excellent. Environmental Fate of mixing two bodies of water with variable water quality Because water is not simply released into Leesville Lake but also pumped back into SML creates a very complex water quality scenario requiring in depth analysis. Extended periods of pump back degrade SML water quality near the dam while extended periods of release in LL improve water quality in the headwater section and portion of the confluence with Pigg River. Additionally, extended periods of pump back will provide greater water quality improvements to LL by removal of Pigg River contaminants but degrade SML with these additions. How can this be managed? Is it acceptable to variably control water quality based purely on electrical demands? I will try to answer this question. 55

65 Section 4.1 of this analysis clearly suggests that LL is moderately eutrophic. It is relatively consistent in this designation with slight inter-annual variations. Yet one trend is beginning to develop. Station at Toler Bridge (headwaters of LL) TSI is actually now better than the remainder of the lake. Consider water quality of SML TSI of 60 in headwaters with TSI of 40 near the dam. This is a typical reservoir pattern. The reverse developed in LL during It remains to be seen if this pattern persists. The analysis in section 4.2 suggests that traditional limnological analysis is not adequate to explain these patterns. Entry of TP from Pigg River is not expressed (at least through correlation analysis) as Chlorophyll a in the reservoir as a predictable pattern. Concentrations of Daphnia do not provide explanations either. Also, TSI measured as Secchi Depth is consistently better (mesotrophic) than measures of TP and Chlorophyll a. Further analysis on August 26 was conducted. Clearly, operations were pumping back Pigg River water (or were in some stage of the process) as visualized by the discolored water throughout the lake moving toward SML Dam. I took a water sample at MM14 for analysis. Here is the analysis: Table 4.1 Comparisons of E. coli and TP at key stations in headwaters of Leesville Lake on August 26, Toler Bridge Pigg River MM 14 Tail Water E. coli (cfu/100 ml) TP (mg/l) The pervasiveness of this problem is strongly suggested from this analysis. Clearly, water entering from Pigg River is elevated in nutrients and bacteria. It is being drawn toward SML dam degrading areas as it moves. Additionally, Toler Bridge station water quality is degraded as well. And then water quality at bridge near SML dam has elevated E. coli and nutrients (analysis of elevated and degraded are based on data in previous sections of the report). What are the dynamics at work here? It appears this may result from water movement back and forth throughout this area of the reservoir. So what is environmental fate of these water quality parameters. Clearly this portion of the reservoir is degraded and those recreating, fishing or living in this portion of the reservoir are experiencing degraded water quality from this operation. I suggest depending upon duration of the pump back release portions of SML near the dam are degraded as well. Movement of degraded water is pervasive (as shown at MM14) and is mobile. Operations in this case are degrading SML water quality for those recreating near the dam. The other question is the entire water quality of LL? What are the benefits and or risks of this operation? Clearly, flow though of water from SML would provide the greatest benefit to LL. Near oligotrophic water would mitigate polluted Pigg River water and provide levels of improvement. Thus logically the lack of this effect degrades water quality of LL. But by how much and to 56

66 what extent is needed for analysis? Again, I believe the analysis of TSI based on Secchi Depth may provide some insight to this analysis. We generally observe greater Secchi Depths than expected based on concentrations of Chl a and TP. While I integrate Chl a for an overall measure it is clear that the lake develops very high concentrations of Chl a at 5-8 meters of depth in summer. Additionally, the reservoir stratifies in summer months isolating the hypoliminion with resulting loss of oxygen at greater depths. This pattern of stratification strengthens from headwaters to the dam. Thus it is this cooler and mixed Pigg River water that is pushing down the reservoir. So in a typical situation, cool SML hypolimnion water flows into the reservoir pushing to the point of stratification where it would naturally move below the warm and stratified eplimnion. Integrating into the lake and traveling through the hypolimnion. In this instance, warm and polluted Pigg River water is mixed with this hypolimnion creating a warmer mix of polluted water. We have a constantly mixed headwater section flowing into a stratified layer of the lake at the transition portion of the reservoir. When flow is reversed, water is drawn through the turbines and mixed and then returned to SML. This more than likely serves to completely mix the waters and effectively create eutrophic conditions in SML. Secchi Depth may be greater because this constant mixing interferes with natural biorhythms of the plankton. Also mixing with very clear hypoliminion of SML. The well mixed water reduces water quality and pushes it down stream. The previous analysis of this relationship was examined to look at the largest influence on water quality in the reservoir water quality at the Pigg river. The Pigg river is arguably the greatest source of nutrients and sediment to the reservoir. Conversely, Smith Mountain Lake dam operations and the mixing of water from that reservoir provides the greatest dilution effect. The attempt of analysis here is to begin quantification of this relationship. Pigg River inputs in relationship to SML dam release is the essential driving force on water quality with the exception of hydrology during wet years (such as the wet year of 2013). Section 5: Management Implications Analysis of the current data is valuable for making management recommendations. By extending TSI analysis from the 2013 report we see trends returning to historical averages (Figure 5.1). Water quality of the Pigg River remains at relatively poor levels but much improved TSI and water conditions downstream through Leesville Lake to the dam. The dilution or lessening of impacts from the Pigg River (unlike 2013 observations) are generally observed in the lake at Toler Bridge. Thus deteriorating water quality at Pigg River does not equate to poor 57

67 water quality at the dam. The lake remains in a mildly eutrophic state Pigg River Toler Dam Figure Trophic State Index (TSI) based upon TP measurements in Leesville Lake from Y axis reflects average TSI for the entire sampling year for each of the three primary sampling stations throughout the reservoir. Based upon the water quality analysis in Figure (5.1) it is inferred SML operations can create potentially worsening water quality throughout the reservoir. This suggests: Smith Mountain Lake (SML) operations should be coupled with water quality observations. The monthly tail water data collected for this report are helpful but only provide snap shot data of water quality exiting SML. Volumes of water pumped back and forth between Leesville Lake (LL) and SML, flow rates of Pigg River and times of dam operation are critical to proper understanding and management of water quality. Continued efforts to control Pigg River water quality are necessary. This remains a concern particularly during months of high energy generation at SML because pump back operations are more pronounced during these months. Leesville Lake is more vulnerable to water quality deterioration during high pumping into SML and high flow from Pigg River because of the movement toward the dam increases contact time in Leesville Lake and the mixing effect it creates. 58