Details will be added as they become available.
Agenda subject to change.
★ Denotes that the lead author is a student
Updated 6 October 2018
7:30 am – 8:30 am
Continental Breakfast / Exhibits Open
8:30 am – 10:00 am
Concurrent Session H
- Evaluation of CyanoDTec Multi-Plex qPCR Assay as a Cyanotoxin Screening Tool for Ohio Public Water Systems and Inland Lakes
Evaluation of CyanoDTec Multi-Plex qPCR Assay as a Cyanotoxin Screening Tool for Ohio Public Water Systems and Inland Lakes
Heather A. Raymond1, Ruth A. Briland1, and Jorge Santo Domingo2
1Ohio Environmental Protection Agency, Division of Drinking and Ground Waters, Columbus, Ohio; 2US Environmental Protection Agency, Office of Research and Development, Cincinnati, Ohio
Ohio EPA utilized the CyanoDTec qPCR assay to quantify total cyanobacteria (16S rDNA), and microcystin (mcyE), saxitoxins (sxtA), and cylindrospermopsin (cyrA) genes at 118 public water system source waters and 24 inland lakes. Samples were collected biweekly year-round at PWSs for qPCR and MC-ADDA ELISA analysis. Saxitoxins and cylindrospermopsin were analyzed if sxtA or cyrA were detected. All three cyanotoxins were analyzed and paired with phytoplankton enumeration at inland lakes. mcyE was detected in source waters for 57 PWSs and six inland lakes and microcystins were detected at 45 PWSs and five inland lakes. The number of samples positive for microcystins but negative for mcyE was low (2% for PWS; 15% for inland lakes). At several sites, detection of mcyE preceded microcystins detections by 1–4 weeks. sxtA was detected at 33 PWSs and 14 inland lakes, and saxitoxins were detected at 15 PWSs and 10 inland lakes. Less than 2% of PWS and inland lake samples had saxitoxins detections without corresponding stxA detections. Samples with cyanotoxin detections that lacked corresponding gene detections often occurred following bloom senescence and cyanotoxin concentrations were low. At one PWS, mcyE, sxtA, and cyrA were all detected, demonstrating multi-plex assay functionality. An interlab method comparison was conducted on a subset of samples. qPCR results out-performed cyanobacteria cell counts as a predictor for inland lake cyanotoxin production. 16S rDNA sequencing analyses linked most cyanotoxin positive samples to Planktothrix or Microcytis species, although in a few samples dominant species were Aphanizomenon, Dolichospermum, Cylindrospermopsis, Phormidium, and Leptolyngbya.
- Using Molecular Analyses to Help Understand and Manage Waters Affected by Cyanobacterial Harmful Algal Blooms
Using Molecular Analyses to Help Understand and Manage Waters Affected by Cyanobacterial Harmful Algal Blooms
Erin Stelzer1, Amie Brady1, Jessica Cicale1, Joseph Duris2, Mary Anne Evans3, Donna Francy1, Carrie Givens4, and Keith Loftin5
1USGS Ohio-Kentucky-Indiana Water Science Center, Columbus, Ohio; 2USGS Pennsylvania Water Science Center, New Cumberland, Pennsylvania; 3USGS Great Lakes Water Science Center, Ann Arbor, Michigan; 4USGS Upper Midwest Water Science Center, Lansing, Michigan; 5USGS Kansas Water Science Center, Lawrence, Kansas
Toxic cyanobacterial harmful algal blooms (cyanoHABs) are of concern in many parts of the world because of their effects on drinking water, water-based recreation, and watershed ecology. These toxins have been implicated in human and animal illness and death in over 50 countries and in at least 36 states in the United States. Human health risk from cyanoHABs is commonly associated with ingestion or inhalation of toxins. Microscopy has been used traditionally to identify and quantify the different cyanobacterial genera; however, not all strains within a genera have the ability to produce a toxin. Also, in recent years it has become apparent that the microbial community plays a role in determining if and/or which cyanobacterial strains become dominant during a bloom. Molecular methods such as quantitative polymerase chain reaction (qPCR) and next generation sequencing are useful tools for understanding and managing waters affected by cyanoHABs.
This presentation highlights two USGS-led research studies that feature molecular methods. The first study uses monitoring and prediction tools to help make informed decisions on potential occurrence of harmful levels of toxins in recreational and drinking waters. Site specific models are developed using factors significantly related to toxin concentrations, including concentrations of cyanobacterial genes, at Lake Erie and inland lakes in Ohio. The second study is designed to better understand the abiotic and biotic factors that influence cyanoHABs and toxins. This study is focused in the western basin of Lake Erie, but other sites include Saginaw Bay, Lake Huron and Grand Traverse Bay, Lake Michigan.
- Structure and Physiological Activity of Cyanobacterial Communities in a Freshwater Lake: A Three-Year Study Using 16S rRNA Gene Sequencing Analysis
Jorge Santo Domingo
Structure and Physiological Activity of Cyanobacterial Communities in a Freshwater Lake: A Three-Year Study Using 16S rRNA Gene Sequencing Analysis
Jorge W. Santo Domingo, Aabir Banerji, Mark Bagley, Jody Shoemaker, Daniel R. Tettenhorst
US Environmental Protection Agency, Office of Research and Development, Cincinnati, Ohio
While cyanobacteria are common phototrophic inhabitants of natural water systems, they can also pose significant hazard to humans and other biota via toxic by-products known as cyanotoxins. Standard cyanobacterial monitoring relies on time consuming microscopic methods that may not easily discriminate between different groups and that do not provide information on their physiological status. To circumvent these issues, we used next-generation sequencing to generate 16S rRNA gene metabarcoding libraries for water samples collected from five different sites within a multipurpose freshwater reservoir. Samples were collected over three consecutive years from May to September and both DNA and RNA were used to determine the diversity, relative abundance and physiological activity of the cyanobacteria identified. Analysis of nearly 30 million sequences revealed the presence of 16 different genera within the lake. Of the cyanobacteria known to produce cyanotoxins, Dolichospermum, Planktothrix, Microcystis, Cylindrospermopsis, Aphanizomenon, and Pseudanabaena were the most abundant (in that order). Temporal changes were noted in both relative abundance and activity, with Dolichospermum showing the highest levels early during the monitoring period. Sizeable increases in the other aforementioned genera followed after mid-June. Parallel increases in microcystin levels and Microcystis abundance were noted, implicating the latter cyanobacterial group as primarily responsible for toxin production. In summary, we showed that metabarcoding is a robust tool for assessing the diversity of cyanobacteria in natural systems. The results provide the foundation for understanding the population dynamics of cyanobacteria in relation to toxic cyanobacterial blooms.
- Nitrogen–Phosphorus-Associated Metabolic Activities and Community Structures During the Development of a Cyanobacterial Bloom Revealed by Metatranscriptomics
Nitrogen–Phosphorus-Associated Metabolic Activities and Community Structures During the Development of a Cyanobacterial Bloom Revealed by Metatranscriptomics
Jingrang Lu1, Bo Zhu2, Ian Struewing3, Ning Xu2, and Shunshan Duan2
1US Environmental Protection Agency, Office of Research and Development, Cincinnati, Ohio; 2Institute of Hydrobiology, Jinan University, Guangzhou, Guangdong, China; 3Pegasus Technical Services, Cincinnati, Ohio
The increasing harmful cyanobacterial blooms (HABs) have potentially had threat to human health and ecosystem stability, and HAB control has been focused on the reduction of nutrients. However, recent studies suggest that nitrogen (N) from cyanobacterial N2-fixation may contribute to HABs. Our analysis of metatranscriptomic sequences from Harsha lake, Ohio, revealed the expression of upregulated gene clusters associated with nitrogen and phosphorus (P) metabolism prior to and during a cyanobacterial bloom event. Genes involved in N2-fixation (nifDKH) and P transport and regulation were significantly upregulated during the bloom compared to a pre-bloom reference date. Nostoc and Anabaena had major roles in N2-fixation. However, other cyanobacteria like Cylindrospermopsis, Cyanothece, Arthrospira Trichodesmium, etc. were also important. The activities of N2-fixation were associated with high P and low N or low N/P ratios and high relative abundance of active cyanobacterial N2-fixers, while those of phosphorus accumulation were associated with low P or high N/P ratios and increasing Microcystis. The results indicate that the early summer N2-fixation activities linked to the decreased N/P ratios, the existing active N2-fixers, a following HAB, cyanobacterial community successions and cyanotoxin productions.
- A Water and Mass Balance Model for Evaluating Phosphorus Pathways and Lake Improvement Strategies in Three Shallow, Eutrophic Lakes in the Upper Midwest
A Water and Mass Balance Model for Evaluating Phosphorus Pathways and Lake Improvement Strategies in Three Shallow, Eutrophic Lakes in the Upper Midwest
Charles Ikenberry1, Bob Gregalunas2, Sara Mechtenberg2, and Mike Sotak2
1FYRA Engineering, Des Moines, Iowa; 2FYRA Engineering, Omaha, Nebraska
It is well-established that phosphorus is typically the limiting nutrient for algal growth and a driver of eutrophication in freshwater lakes. Therefore, phosphorus reduction is a common objective of lake management. Many improvement projects utilize a “random acts of conservation” approach while planning efforts utilize simplistic models that predict average, steady-state conditions. This presentation describes a dynamic and comprehensive water and mass-balance modeling approach that quantifies distinct phosphorus pathways and potential impacts of water quality improvement strategies in shallow, eutrophic lakes.
The approach utilized GoldSim, a simulation software for dynamic modeling of complex systems. The software employs Monte Carlo methods to quantify uncertainty, which aids the decision-making process. Key inputs and processes represented include precipitation, streamflow, evaporation, outlet configuration, groundwater/seepage, pumping for irrigation and water supply, phosphorus sedimentation, and sediment-phosphorus release, which was informed by sediment core chemistry.
Annual loading rates from external sources varied between lakes, ranging from 0.7 to 11.7 g-P/cm2, while internal loads varied from 0.7 to 10.5 g-P/cm2. Relative importance of internal loading varied with time, but was similar across lakes, with growing season internal loads accounting for 40% to 60% of total load. Phosphorus reduction goals ranged from 40% to 70%. Simulated improvement alternatives included reduction of external phosphorus, diversion of inflows, rough fish management, in-lake wetlands, dredging, and internal load control. Due to unique watershed and lake characteristics, effectiveness of improvement alternatives varied by lake. Stochastic simulation informed the decision-making process by identifying important data gaps and quantifying the probability of goal attainment.
- Modeling Phosphorus and Nitrogen Loading Throughout the Entire Great Lakes Basin using SPARROW
Modeling Phosphorus and Nitrogen Loading Throughout the Entire Great Lakes Basin Using SPARROW
Glenn Benoy1, Dale Robertson2, Dave Saad2, Ivana Vouk3, and Richard Burcher3
1International Joint Commission, Ottawa, Ontario, Canada; 2US Geological Survey, Middleton, Wisconsin; 3National Research Council, Ottawa, Ontario, Canada
Eutrophication problems in the Great Lakes are caused by excessive nutrient inputs (primarily phosphorus, P, and nitrogen, N) from various sources throughout its basin. In order to develop nutrient protection and restoration plans, it is important to understand where and from what sources the nutrients originate. As part of a binational effort, new SPARROW (SPAtially Referenced Regression On Watershed attributes) watershed models were developed to simulate P and N loading in streams throughout the entire Great Lakes Basin; previous SPARROW models only simulated US contributions. The new models cover the entire Basin at higher resolution (~2 km2 catchments) enabling improved descriptions of where nutrients originate and what are the dominant sources of P and N at various spatial scales. The new models were developed using harmonized geospatial datasets describing the stream network, nutrient sources (location and quantity), and the environmental characteristics affecting nutrient delivery. The models were calibrated using loads estimated from sites monitored by US and Canadian organizations. Model results are being used to estimate the P and N input to each of the Great Lakes, compare loading and yields from various tributaries and governances, and estimate the relative importance of each nutrient source, including the upstream lakes.
- Long-Term Shallow Lake Nutrient and Water Quality Management in an Agricultural Watershed Using Conservation Management Practices
Long-Term Shallow Lake Nutrient and Water Quality Management in an Agricultural Watershed Using Conservation Management Practices
Richard Lizotte, Martin Locke, Lindsey Yasarer, Ronald Bingner, R. Wade Steinriede
USDA-ARS National Sedimentation Laboratory, Oxford, Mississippi
Because of intensive row-crop agriculture in the Lower Mississippi River Basin, freshwater systems in the basin are characterized by elevated suspended sediment, eutrophication and poor water quality. The study lake, Beasley Lake, is a shallow isolated oxbow lake that suffered from poor water quality prior to expansion or implementation of several conservation management practices. Practices included: edge-of-field vegetated buffers (VB); constructed sediment pond (SP); conservation reserve areas (CRP); and within-field conservation tillage. Over a 20-year period (1998–2017) measured water quality included suspended sediment (SS), Secchi visibility depth (Secchi), soluble orthophosphate (PO4-P), total phosphorus (TP), nitrate nitrogen (NO3-N), ammonium nitrogen (NH4-N), total nitrogen (TN), and chlorophyll a. During the 20-year study period water quality showed significant improvement. SS decreased > 72% from 1998–2002 due to implementation of VB in 2001–2002. Concomitant with SS reduction, Secchi increased > 5-fold from 1998–2008. Phosphorus as PO4-P decreased nearly 90% from 2002-2015 after SP construction while TP decreased > 90% from 1999–2017 due to VB implemented in 2001–2002 and expanded to attract quail (Colinus virginianus) in 2006. Nitrogen as NO3-N decreased > 95% nearly identical with TP. NH4-N first decreased by > 95% from 1999–2005 due to VB and CRP but then increased 10-fold from 2009–2014 due to SP. In contrast, TN appeared to be unaffected by any conservation practice. Algal biomass, chlorophyll a, increased 8-fold from 2005–2012 due to decreasing SS and increasing Secchi after VB implementation. The study provides evidence of decreased SS and nutrients improving water quality as a result of conservation management practices.
- LakeKeepers: Expanding Citizen Based Monitoring in Alberta, Canada
LakeKeepers: Expanding Citizen Based Monitoring in Alberta, Canada
Bradley Peter and Laura Redmond
The Alberta Lake Management Society, Edmonton, Alberta, Canada
Current lake monitoring strategies, such as the Alberta Lake Management Society’s LakeWatch program, restrict much of the Alberta’s data to lakes easily accessible from major urban centres – however, many of Alberta’s invaluable water resources exist outside of this range. As a result of the remote nature of many of these lakes, water quality data and monitoring history is minimal. The LakeKeepers pilot project aims to address the gaps in lake water quality data that exist in many parts of Alberta. LakeKeepers was piloted at five lakes in Alberta during the summer of 2018, allowing citizen scientists to collect information on temperature, nutrients, chlorophyll a, clarity, and invasive species. This presentation will: include an overview of the Alberta Lake Management Society, include a discussion of the LakeKeepers program design, including training materials and videos, present the results from the first year of monitoring, and explore the successes and challenges faced in the delivery of the program.
- Combining Citizen Science with Remote Sensing to Monitor Lake Storage
Combining Citizen Science with Remote Sensing to Monitor Lake Storage
Grant Parkins1, Tamlin Pavelsky2, Sarah Yelton1, and Megan Rodgers1
1Institute for the Environment, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; 2Department of Geological Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
Of the 20–40 million lakes in the world larger than 0.01 km2, only a few thousand receive regular water level monitoring. On-the-ground, automated monitoring of a fraction of these lakes would incur considerable expense. However, an inexpensive staff gauge installed in a lake can be read by anyone, making this an attractive alternative if a system is in place to collect and report the data.
The Lake Level Monitoring Project (LLMP) engages citizen scientists in monitoring lake levels at regular intervals. This data is combined with lake surface area measurements, calculated using satellite imagery from Landsat8 and Sentinel 2 satellites, in an effort to understand how the quantity of water stored in lakes changes over time.
In the first year of the project, LLMP has collected more than 700 lake level and 300 lake area measurements from 11 lakes in eastern North Carolina. We have found that lake level measurements submitted by citizen scientists are highly accurate when compared to pressure transducers installed at the same sites. We have found that lake stage variations are correlated within local clusters of lakes but have found that correlations among distant lakes are not significant.
During this session, we also share strategies for developing a citizen science project, consider the motivations of citizens who participate in LLMP, and discuss feedback they have provided regarding our data reporting systems. Finally, we share plans for expanding our lake network to 200 additional lakes in the United States, Europe, and Asia within 3 years.
- In Search of the Complete Picture: Indiana Lakes Trophic Classification Comparison Across Citizen Science, State, and National Monitoring Programs
★ Heather Bearnes-Loza
In Search of the Complete Picture: Indiana Lakes Trophic Classification Comparison Across Citizen Science, State, and National Monitoring Programs
Heather Bearnes-Loza and Sarah Powers
Indiana Clean Lakes Volunteer Lake Monitoring Program, Bloomington, Indiana
Lake monitoring programs across the country are designed to meet specific needs. The Indiana Clean Lakes Program was developed in 1989 in partnership with the Indiana Department of Environmental Management’s (IDEM’s) Office of Water Quality to facilitate a multifaceted approach for assessing Indiana’s lakes. The primary monitoring goals of this program are to assess Indiana’s lakes utilizing snapshots of water quality through random annual samplings, and on a long-term scale using volunteer citizen scientists to collect data at the same lakes over time. The National Lakes Assessment (NLA) and its state intensification program is an additional monitoring tool used in Indiana to help understand our lakes and the relationships to other lakes across the nation.
Each of these monitoring methods is unique. Direct comparison of the trophic classification of Indiana’s lakes in 2007, 2012, and 2017 reveals distinct differences in the distribution of lake trophic classes in Indiana through each of these monitoring programs. In this talk, we will look at these differences, explore the likely causes, and demonstrate the need and value of each program as a distinct monitoring tool.
- Lake Observer: A Mobile App for Recording Lake and Water Quality Observations Across the Globe
Lake Observer: A Mobile App for Recording Lake and Water Quality Observations Across the Globe
Kathleen C. Weathers1, Holly A. Ewing2, Kenneth Chiu3, #Lisa Borre1, and Michael Forcella4
1Cary Institute of Ecosystem Studies, Millbrook, New York; 2Bates College, Lewiston, Maine; 3Binghamton University, Binghamton, New York; 4State University of New York New Paltz, New Paltz, New York
Mobile apps are rapidly gaining ground as effective tools for collection and display of scientific and environmental monitoring data. The Lake Observer app project began in 2010 as a partnership among computer, ecosystem, and citizen scientists working with the Global Lake Ecological Observatory Network (GLEON) and Lake Sunapee Protective Association (LSPA). Project partners were interested in developing a tool that allows for easy submission of geo-referenced lake data by research scientists and citizen scientists using a smartphone or tablet. Now available in Android, iOS and web-based formats, the app allows users to record and submit data on water quality, Secchi depth, ice cover, cyanobacteria, and aquatic vegetation while working in the field. Since 2015, Lake Observer has been in use for the Secchi Dip-In, and through a partnership with NALMS and USEPA, collected data are publicly available via the Water Quality Portal. In 2018, the app will be used by an interdisciplinary team of researchers from the Cary Institute of Ecosystem Studies, Dartmouth, and the University of New Hampshire who are developing high-tech tools to monitor cyanobacteria in lakes, predict impending blooms, and identify factors that are degrading water quality. The team will bring together multiple data types collected via satellite, drone, and mobile app. Remotely-sensed data from four lakes in the Northeast will be verified with in-lake sampling data, including those collected by citizen scientists using Lake Observer. Preliminary results, from the perspective of app data collection, will be shared along with a demonstration of the app’s latest features.
- Damaging Solar UV Radiation as an Environmental Regulator of the In situ Abundance of Mosquito Larvae: A Test of the Relative Importance of Shading from Damaging Solar UV Radiation by DOM and Organismal Capabilities for DNA Repair
★ Nicole Berry
Damaging Solar UV Radiation as an Environmental Regulator of the In situ Abundance of Mosquito Larvae: A Test of the Relative Importance of Shading from Damaging Solar UV Radiation by DOM and Organismal Capabilities for DNA Repair
Nicole Berry, Craig Williamson, and Erin Overholt
Miami University, Oxford, Ohio
Dissolved organic matter (DOM) is decreasing the transparency of inland waters to ultraviolet radiation (UV), and in turn reducing the potential for sunlight to disinfect surface waters of parasites and pathogens. Northeastern North America (NENA) has experienced over a doubling of DOM concentrations in the last decade, suggesting substantial reductions in solar disinfection potential in this region. Here we extend previous work on the solar disinfection of parasites and pathogens to examine the effects of DOM and reduced exposure to solar UV radiation on disease vectors. Mosquitoes are vectors of disease that are most abundant in shaded habitats and are expanding their habitat range northward into NENA due to increases in both precipitation and average air temperature. Here we ask whether increases in DOM and reductions in solar UV disinfection facilitate the expansion of mosquitoes. We tested the potential for solar UV radiation to be an environmental regulator of mosquito larvae and compared two potential mechanisms for mitigating damage caused by exposure to solar UV radiation: 1) DOM as an environmental mediator to reduce exposure to UV, and 2) photoenzymatic repair as an organismal response to repair DNA damage caused by solar UV radiation. DOM significantly accelerated time to emergence. Exposure to solar UV radiation significantly increased time to emergence. These findings highlight the potential value of solar UV radiation as a natural control of vectors of disease and the importance of considering changes in water transparency in predicting mosquito breeding success and range expansion into NENA.
- An Emerging Technology Using a Resilient Fabric Material for Living Shorelines
An Emerging Technology Using a Resilient Fabric Material for Living Shorelines
Bruce Richards and Brian Fischer
Sox Erosion Solutions, Boca Raton, Florida
Shoreline erosion contributes to excessive losses of soil and sediment, reducing habitat in freshwater ecosystems; a new living shoreline fabric approach may be the answer. Established practices of vegetative buffering and habitat restoration are of increasing importance to policy-makers, water managers, engineers, and municipal officials. There is overwhelming scientific consensus that each coastal state will experience increased erosion due to the inevitable future rise of sea level attributable to climate change; non-coastal states will follow. A relatively recent holistic approach to stabilizing shorelines is gaining international momentum utilizing a proprietary patented bioengineered material distributed by Sox Erosion Solutions of Boca Raton, Florida. This rigorous fiber technology has been in place for 18 years and has sustained shorelines with jagged rocky shores along high wave energy embankments. Native plants have been integrated into the fabric shorelines to improve buffering of nutrients particularly phosphorus which adheres to fine grain surface sediments. This presentation will show before and after data of successful installations in a relatively short temporal scale. We will examine data collected from field studies on native plant recruitment, and shoreline habitat improvement. The conclusion will highlight key lessons learned specifically for lake managers. Our presentation will also review our future research project goals as possible opportunities for students or engineering firm collaborations.
- Are Carbon Emissions from Lakes on the Rise? Investigating Organic Carbon Degradation by Microbes and Sunlight in Inland Waters
Are Carbon Emissions from Lakes on the Rise? Investigating Organic Carbon Degradation by Microbes and Sunlight in Inland Waters
Sarah G. Nalven, Collin P. Ward, Rose M. Cory, George W. Kling, and Byron C. Crump
Wenck Associates, Golden Valley, Minnesota
Inland waters such as lakes and streams are carbon cycling hotspots, emitting as much carbon dioxide (CO2) to the atmosphere as the net amount removed from the atmosphere by land and ocean plants each year (~2 Pg C y-1). Much of the CO2 emitted from inland waters is due to microbial respiration of terrestrially-derived dissolved organic matter (DOM) that is flushed from soils to streams and lakes. Sunlight also affects CO2 emissions from inland waters by directly mineralizing DOM to CO2, and by modifying DOM to new compounds that microbes may consume slower or faster than DOM that has not been photo-altered. Thus, DOM is a critical intermediate between soil organic carbon and inorganic CO2 in the atmosphere. Understanding the controls on DOM conversion to CO2 in inland waters is needed to constrain local and global carbon budgets and to forecast CO2 emission from inland waters under future climate conditions. We conducted an experiment in which DOM leached from the organic layer of tundra soil was exposed to natural sunlight (light treatment) or kept in the dark (dark control), incubated with a soil microbial community, and analyzed for gene expression and DOM composition. This experimental manipulation and the resulting microbial gene expression showed that sunlight exposure of terrestrially-derived DOM initially stimulated microbial growth by 1) replacing the function of enzymes that degrade higher molecular weight DOM such as enzymes involved in aromatic degradation, oxygenation and decarboxylation and 2) releasing nutrients such as phosphorus and iron. However, photo-production of growth-stimulating compounds came at a cost. Sunlight depleted the pool of aromatic organic compounds that supported microbial growth in the dark control, ultimately causing slower growth in the light treatment over 5 days. These first measurements of microbial gene expression in response to photo-alteration of DOM provide a mechanistic explanation for how sunlight exposure of terrestrial DOM causes rapid changes to microbial degradation of organic carbon.
- Winter Road Maintenance: Identifying and Lowering Private Companies’ Barriers to Adopting Best Management Practices
★ Holden Sparacino
Winter Road Maintenance: Identifying and Lowering Private Companies’ Barriers to Adopting Best Management Practices
Holden Sparacino and Kristine Stepenuck
University of Vermont, Burlington, Vermont
Winter road maintenance keeps roads free of snow and ice, but can also negatively impact surface water quality, pose risks to aquatic life, and may contaminate groundwater and increase risks of contamination for private wells or public drinking supplies sourced from groundwater. Many municipalities have adopted preventative measures (best management practices) to reduce salt use as environmental impacts have grown and materials costs have risen to minimize environmental impacts and save money while providing a similar level of service.
However, it is largely unknown if private contractors who maintain private roadways, driveways, commercial parking lots, and sidewalks have adopted these practices, and what their motivations and barriers to adopting best management practices are. In this talk, an ongoing mixed-methods study in the Lake Champlain Basin and preliminary results will be discussed. The study seeks to identify the current practices of private contractors through quantitative survey data, using these findings to inform qualitative interviews to further explore the barriers and motivations of private contractors to adopt best management practices. Mixed-methods data will be used to create reccomendations for community-based social marketing outreach and learning opportunities for contractors. Ultimately the study and recommendations aim to increase private contractors’ awareness of environmental and economic outcomes of their practices and lower barriers to adopting new, lower salt best management practices.
10:00 am – 10:30 am
Refreshment Break / Exhibits Open
10:30 am – 12:00 pm
Concurrent Session I
- Evidence-Based Guidelines for Microbial Source Tracking Projects
Evidence-Based Guidelines for Microbial Source Tracking Projects
James Herrin, Mauricio Larenas, Daron Stein, and Yiping Cao
Source Molecular Corporation, Miami, Florida
Lake and reservoir managers face diverse challenges maintaining water quality to support multiple uses. Fecal bacteria are a leading cause of impairment in these systems in the United States. Methods used to monitor indicator bacteria do not provide information about the source of the pollution and remediation is difficult, particularly in watersheds with nonpoint sources. Advances in microbial source tracking (MST) technologies are revealing the source of fecal bacteria.
Focusing on lessons learned and outcomes achieved from two MST projects, we will present evidence-based guidance on crafting effective MST programs.
1) The City of Boise closed multiple beaches after measuring high levels of E. coli. Water samples were analyzed for dog, goose and human bacteria. Results indicated consistent pollution from dogs. Human and goose fecal biomarkers were detected less frequently. Parks officials imposed stricter regulations on dogs at these sites, E. coli concentrations decreased, and the beaches were reopened.
2) Sunshine Lake and Sunrise Waterway system in Charlotte County, Florida experienced persistent algal blooms. Officials initiated a monitoring program that included fecal bacteria to develop a management plan. Water samples were analyzed for bird, dog and human fecal bacteria. The frequencies of detection were less than 1%. An experiment revealed that decomposing grass clippings created a greater spike on fecal coliform plates than either soil or dog waste collected around the lake.
- Adaptation of Lake Erie Planktothrix Blooms to Shifts in N Availability
★ Michelle Neudeck
Adaptation of Lake Erie Planktothrix Blooms to Shifts in N Availability
Michelle Neudeck, Robert M. McKay, and George Bullerjahn
Bowling Green State University, Bowling Green, Ohio
Sandusky Bay (Lake Erie) harbors a toxic persistent cyanobacterial HAB from May through October in which microcystin levels can routinely exceed 20 ppb. The waters are shallow, turbid, and eutrophic, providing ideal conditions for Planktothrix, the dominant cyanobacterium. N levels are high while Sandusky River discharge is high, but due to denitrification DIN rapidly decreases to below detection when river discharge is low. Planktothrix persist under the conditions of low N, despite being non-diazotrophic. Metatranscriptomic data demonstrates Planktothrix actively stores N under replete conditions by producing cyanophycin, a N storage polymer. It is able to retrieve N from cyanophycin during depleted conditions through production of the enzyme cyanophycinase. Under prolonged N deprivation, Planktothrix produces the transcripts for nblA, which encodes a protein that can trigger the degradation of the phycobilisome to be used as an additional N source. Even though the bay is turbid, Planktothrix is under light stress as indicated by the transcription of a high light stress inducible protein, hliA. These physiological features present management challenges distinct from those employed to mitigate Lake Erie Microcystis blooms.
- The Heidelberg Tributary Loading Program: Perspectives from Between the Land and Lake
The Heidelberg Tributary Loading Program: Perspectives from Between the Land and Lake
Laura Johnson, David Baker, Remegio Confesor, and Ellen Ewing
Heidelberg University, Tiffin, Ohio
The National Center for Water Quality Research has been monitoring major tributaries to Lake Erie for over 40 years as a part of its Heidelberg Tributary Loading Program (HTLP). A minimum of one sample and, during storm runoff, up to three samples a day are analyzed for all major nutrients and suspended sediments from five major tributaries to Lake Erie (Maumee, Sandusky Portage, Raisin and Cuyahoga). Long-term trends in loads and concentrations indicate that total phosphorus (TP) has decreased since the mid-1970s in the agricultural watersheds, whereas dissolved reactive P (DRP) has been increasing drastically since the mid-1990s corresponding to the recurrence of harmful algal blooms (HABs) in Lake Erie. Increased DRP and HABs appear to be associated with increased discharge in the past decade as well as recent patterns in agriculture, specifically the build-up of P at the soil surface combined with preferential flow of water to tile drainage. This high frequency water quality monitoring has allowed us to detect dominant sources and dynamics of nutrient runoff from watersheds throughout Ohio and in Michigan. The HTLP has been immensely useful in detecting causes for reeutrophication of Lake Erie, setting new Lake Erie phosphorus target loads, and determining seasonal forecasts for western Lake Erie HABs. By continuing to monitor tributaries to Lake Erie, inland lakes, and the Ohio River, we should be able to adaptively manage our watersheds to ensure future conservation efforts and those already underway are successful.
- Assessment of Lake of the Woods’ Internal Phosphorus Loading
Assessment of Lake of the Woods’ Internal Phosphorus Loading
Julie Blackburn1, Geoff Kramer1, Jesse Anderson2, and Cary Hernadez2
1RESPEC, Roseville, Minnesota; 2Minnesota Pollution Control Agency, Duluth, Minnesota
Lake of the Woods (LOW) is an international water that covers 1,485 mi2 (3,846 km2) and experiences elevated phosphorus concentrations that peak with progression of the growing season generating algal blooms that may extend into the autumn. LOW is impaired by excess nutrients and a MPCA sponsored Total Maximum Daily Load (TMDL) study for the lake’s Minnesota portion was initiated in 2015. This massive lake has been the subject of intense study by MPCA, Canadian provinces of Ontario and Manitoba, Canada Ministry of Environment and Climate Change, the Science Museum of Minnesota (SMM) and the International Joint Commission (IJC). The studies and projects completed include lake water quality samples, automated lake temperature/dissolved oxygen profiles (SMM), updated satellite land cover (UM), HSPF and BATHTUB modeling (RESPEC) and intensive lake sediment P studies (UW Stout). These studies have generated data necessary to develop estimates of internal loading, an important driver of LOW water quality issues but difficult to measure due to the size and complexity of this lake. Converging estimates of internal P loading (about 300 m tonnes per year) were defined by three independent studies with different methodologies: 1) temperature dependent lake sediment P release (UW Stout); 2) historical examination of lake mass balances (SMM); and 3) HSPF monthly P mass balances from the entire watershed with corresponding lake P masses (RESPEC). The results of these studies are being incorporated into discussions for future management decisions by Canadian and US partners responsible for management of Lake of the Woods.
- Spatiotemporal Assessment of Water Chemistry Dynamics in the Coastal Dune Lakes
Spatiotemporal Assessment of Water Chemistry Dynamics in the Coastal Dune Lakes
Alexander C. Hyman1,2 and Dana Stephens1
1Mattie M. Kelly Environmental Institute, Northwest Florida State College, Niceville, Florida; 2Choctawhatchee Basin Alliance, Santa Rosa Beach, Florida
Coastal dune lakes of Northwest Florida experience fresh and brackish conditions corresponding to exchange of waters with the sea through breaching of a berm. Decadal-scale trends and multivariate analyses of monthly water chemistry data (i.e., dissolved organic carbon, chlorophyll, pH, total phosphorus, total nitrogen, and water clarity) from 18 coastal dune lakes suggested form and function of these aquatic systems influenced interaction among water chemistry variables. Temporal shifts in water chemistry variables indicated trends towards more biologically productive system in 40% of waterbodies monitored. Principal component analysis showed inter-annual water chemistry relationships ordinated by salinity differences among waterbodies. Simple linear regression indicated significant correlations between salinity concentration and total nitrogen, dissolved oxygen, pH, and water clarity. Factor analysis identified two significant factors (marine connectivity and catchment inputs) which were responsible for major variations in inter-annual water chemistry. Identified water chemistry relationships facilitate development of appropriate management plans and aquatic impairment criteria for these unique waterbodies.
- Citizen Science from the Ground Up: UpStream – Building a Public-Private Partnership Between Industry and Public Schools
Ann St. Amand
Citizen Science from the Ground Up: UpStream – Building a Public-Private Partnership Between Industry and Public Schools
Ann St. Amand
PhycoTech, Inc, St. Joseph, Michigan
UpStream is a middle school watershed project that incorporates hands-on science learning opportunities inside, as well as in an outdoor classroom. The program is a cooperative effort between a local environmental consulting firm (PhycoTech, Inc.) and the St. Joseph Public School System. After a two-year search for a teaching partner, UpStream was established in 2005 with one teacher and 28 students. It now includes 11 classes, with over 250 students in the 6th grade and 240 students in the 8th grade for Salmon in the Classroom per year. There has been significant administrative and teacher turnover since 2005, along with a change in state educational goals, guidelines and curricula, yet despite the challenges, the base program is thriving, serving over 2500 students to date. One major advantage of this outreach program is that we are able to interact with all students in the target grades, not only those who already excel in science. Hands-on science has particular efficacy with struggling students and students at risk, connecting them with natural resources in a profound way.
- Social Marketing Maneuvers, Magic, and Measurable Change!
Social Marketing Maneuvers, Magic, and Measurable Change!
Jill Hoffmann1 and Lyn Crighton2
1White River Alliance, Indianapolis, Indiana; 2The Watershed Foundation, North Webster, Indiana
Ever wonder how to create a grassroots public education and engagement program that brings about real, measurable environmental change? How about creating a program where others pay you for the right to promote and widely share your messages about water quality? Join us and become a social marketing magician!
Clear Choices, Clean Water is a social marketing campaign focused on how the choices we make impact our lakes and streams. The program’s unique strategy to increase awareness and knowledge about topics like lawn care, pet waste, native plants, and septic systems has garnered the attention and financial support of dozens of agencies, nonprofits, utilities, and municipalities. The original vision for the campaign was to change people’s behavior about a handful of common water quality issues while simultaneously evaluating the success of such efforts; however, the vision has grown to also include behavior change choices related to water conservation, soil health, tree stewardship, and volunteer participation… and now, Clear Choices has grown in its geographical reach with partner organizations implementing the program in New York, Pennsylvania, Ohio, and Missouri!
We will explore how the pledge map, associated pollution reduction estimates, and various website analytics provide both immediate gratification for the pledgee and real-time evaluation for the program administrators. The objectives for the session are to teach participants how to think through what behavior changes they want; customize a program to fit their audiences; build widespread, lucrative partnerships; and implement a cutting-edge, action-focused public engagement program that transcends nearly every watershed stakeholder group.
12:00 pm – 1:30 pm
Lunch / Exhibits Open
1:30 pm – 3:00 pm
Concurrent Session J
- Annual Patterns of Phytoplankton in Subtropical, Florida Lakes
Annual Patterns of Phytoplankton in Subtropical, Florida Lakes
Dana B. Stephens1 and Daniel Canfield, Jr. 2
1Mattie M. Kelly Environmental Institute, Northwest Florida State College, Niceville, Florida; 2School of Forest Resources and Conservation, University of Florida, Gainesville, Florida
Inter- and intra-annual patterns were examined using 20 to 24 years of monthly chlorophyll concentrations estimates from 27 subtropical, Florida lakes. Dominate periods of variance, reoccurrence of the periods, and strength of the variance (peaks) were extracted using spectral density analysis to address timing and frequency (periodicity) of phytoplankton as well as shifts in periodicity across a continuum of biological productivity. Phytoplankton increased from January to September and linearly decreased through December. Periodicity of phytoplankton was similar in pattern among oligotrophic, mesotrophic, and eutrophic classified waters where phytoplankton reached higher levels during months June through October and lower levels during months November through May. Periodicity of phytoplankton in hypereutrophic waters exhibited bimodal phytoplankton increases in April and October. Variance of periodicity over 20- to 24-year time series showed strength of seasonal phytoplankton patterns were partitioned into quarterly, annual, and centennial time periods. Seasonal variance in mesotrophic and eutrophic lakes occurred on an annual cycle. Phytoplankton peaks in oligotrophic lakes also occurred on an annual cycle, yet weaker seasonal signals were present at quarterly intervals indicating some years exhibited two phytoplankton peaks. Hypereutrophic lakes showed strong annual and quarterly peaks capturing the bimodal phytoplankton pattern throughout out the year.
- Internal Loading of Nitrogen and Phosphorus Supports Non-N-Fixing Cyanobacteria in Honeoye Lake
★ Justin Myers
Internal Loading of Nitrogen and Phosphorus Supports Non-N-Fixing Cyanobacteria in Honeoye Lake
Justin Myers1, Silvia Newell1, Roxanne Razavi2, Lisa Cleckner3, and Mark McCarthy1
1Wright State University, Dayton, Ohio; 2State University of New York, College of Environmental Science and Forestry, Syracuse, New York; 3Finger Lakes Institute at Hobart and William Smith Colleges, Geneva, New York
Honeoye Lake is a small (7.2 km2), shallow (Zmax = 9 m) lake within the Finger Lakes (New York, USA) characterized by an increasing frequency of harmful cyanobacterial blooms. Nitrogen (N) and phosphorus (P) sourced from external (e.g., storm water runoff) and internal loading (e.g., remineralization, N fixation) often control algal growth in lakes. Microbial processes can contribute to nutrient removal (e.g., denitrification) or internal loading. To investigate sediment nutrient dynamics in Honeoye Lake, intact sediment cores were collected in August 2016, June 2017, and September 2017 near the primary tributary inflow and near the middle of the lake. Sediment cores were incubated for three days using bottom water with no amendments (control) or 15N stable isotope additions and sampled daily for nutrients (phosphate, ammonium, nitrate, nitrite, and urea) and dissolved gases (O2 and N2). Sediments were a net source of ammonium (mean 222 ± 106 µmol N m-2 h-1) and ortho-phosphate (mean 1.5 ± 0.2 µmol P m-2 h-1). Reduced N forms dominated the N pool, and nitrate availability limited N removal via denitrification. Internal N and P loading from sediments is periodically mixed to the surface layer by meteorological events, promoting algal blooms and a community shift from N-fixing (e.g., Gleotrichia) to non-N-fixing (e.g., Microcystis) cyanobacterial taxa. Internal recycling of nutrients, sourced from external loads, contributes to sustaining these blooms during low discharge periods. The challenge for lake managers is to effectively reduce nutrient loads of both N and P to reduce occurrences and toxicity of these blooms.
- Reducing Harmful Algal Blooms on a 150-Acre, Hyper-Eutrophic Lake Using a New Biological Treatment Method
Reducing Harmful Algal Blooms on a 150-Acre, Hyper-Eutrophic Lake Using a New Biological Treatment Method
Lake Savers LLC, Richland, Michigan
Lake Heritage is a 150-acre, hyper-eutrophic man-made lake located in Gettysburg, Pennsylvania. The lake is situated in a heavily agricultural watershed. Excessive phosphorus inputs and lack of aquatic vegetation leave the lake susceptible to harmful blue-green algal blooms. Bloom conditions persisted despite frequent treatments with copper sulfate. In addition, this 40-foot-deep lake went anoxic below the 10-foot depth from June through fall turnover.
In 2015, Lake Savers was selected to introduce whole lake aeration, biological treatment and inlet nutrient filtration to restore dissolved oxygen levels and break the cycle of chronic algae blooms. In fall of 2015, whole lake aeration was installed, inlet filtration measures were implemented on the three primary inlet points to the lake.
Improvements in dissolved oxygen levels and reductions in percent organic content of sediments were realized. However, there was no discernable improvement in reduction of harmful algal blooms. The lake remained under advisory for microcystin toxins and harmful algal blooms from early July through October of 2016.
While the community realized turning around the lake was a long-term project, there was no possibility of enduring another summer of a virtually unusable lake in 2017. After extensive research into options and alternatives we partnered with an innovative micro-biology company to develop and implement a completely new approach to Biological Treatment for nutrient reduction in lakes. The approach uses a unique, ex situ “brewing” strategy to dramatically increase the amount of activated, beneficial microbes that can be applied as compared to off-the-shelf formulations.
From May through October, 2 to 4 treatments were applied per month. The program delivered a 90% reduction in blue-green algae with microcystin levels reduced to near non-detect. Total Phosphorus and Dissolved Reactive Phosphorus levels were reduced more than 50% from 2016. Based on these results, we believe that this new approach to biological treatment offers a promising, economically viable alternative to chemical algaecides for the prevention of harmful algal blooms. Further testing on multiple lakes is planned for 2018 and beyond.
- Strategic Management of Cyanobacteria in Drinking Water Reservoirs Using an Action Threshold Based Approach
Strategic Management of Cyanobacteria in Drinking Water Reservoirs Using an Action Threshold Based Approach
West M. Bishop
SePRO Corporation, Whitakers, North Carolina
Algae can cause significant impacts to drinking water quality through production of taste and odor compounds, toxins, and disinfection by-product precursors. Due to the difficulty/expense in removing these compounds in the drinking water process, our approach strategically targeted the source (i.e., algae in raw water) and sought to manage at low densities before these compounds could achieve levels of concern. Operational research will be presented on multiple water supply reservoirs throughout the country with a history of algal influenced taste and odor (geosmin, MIB, etc.) issues negatively impacting the quality of the water supply. Routine monitoring assisted in developing action thresholds for the culprit of taste and odor production and levels were set in accordance to preserve management objectives. If an action threshold was exceeded, the appropriate NSF and/or EPA approved product and concentration was strategically applied to the reservoir to control and prevent the expansion of the targeted nuisance algae. Water sample analysis from all reservoirs consistently documented a 78–97% reduction in nuisance algal densities immediately following the application of SeClear® Algaecide and Water Quality Enhancer or PAK® 27 Algaecide, as well as a decrease in geosmin levels and long-term suppression of nuisance algae. Phoslock was also able to mitigate phosphorus in localized areas and improve water quality. This proactive approach to drinking water management can provide significant and rapid relief of nuisance algae, improve source water quality, and decrease in-plant management inputs required to achieve drinking water objectives.
- From Bench Scale Trials to Effective Full Scale Cyanobacterial Management with Liquid Activated Peroxygen Algaecide/Cyanobactericide
From Bench Scale Trials to Effective Full Scale Cyanobacterial Management with Liquid Activated Peroxygen Algaecide/Cyanobactericide
Tom Warmuth1, John Rodgers2, Brian Sak3, and Tom McNabb4
1BioSafe Systems, East Hartford, Connecticut; 2Clemson University, Clemson, South Carolina; 3San Francisco Public Utilities Commission, Sunol, California; 4Clean Lakes, Inc., Martinez, California
Development of effective treatments for cyanobacterial management are emerging as a needed option as the threat to our water resources by these organisms becomes more realized and understood. The need for tools to cyanobacteria known to produce harmful toxins and taste and odor compounds is an important ongoing focus in the field of surface water management. Bench Scale trials at Clemson University on bloom level densities of cyanobacteria (1.9 million cells/ml) lead to effective field application rates in full-scale surface treatments of a municipal potable water source. The San Antonio Reservoir is a potable water source for the City of San Francisco. It was experiencing high, 100 ppt, levels of Geosmin production from a cyanobacteria dominating the algal assemblage. The San Francisco Public Utilities Commision, through their program of monitoring, sampling and algal enumeration delivered effective control of Dolichospermum spiroides (formerly an Anabaena species) using the lowest labelled rate of a Liquid Activated Peroxygen Algaecide, a NSF/ANSI 60 Certified, liquid activated peroxygen algaecide. Other previous research with peroxide-based algaecides have been identified as effective in selective treatments for cyanobacteria, where it is not greatly affecting non-target organisms, zooplankton, beneficial green algae and other phytoplankton. This all leading to a better potable water source through more targeted treatment and control.
- Patterns in Surface Water Phosphorus Concentrations and Biosolids Utilization in the Upper St. Johns River
Patterns in Surface Water Phosphorus Concentrations and Biosolids Utilization in the Upper St. Johns River
John Hendrickson, Vickie Hoge, Lanie Meridth, and Erich Marzolf
Division of Water and Lands Resources, St. Johns River Water Management District, Palatka, Florida
The headwaters of the upper St. Johns River (USJR) is an integrated aquatic ecosystem of restored herbaceous marsh and run-of-the-river lakes. The SJRWMD owns and manages over 166,000 acres, a significant portion of the area within the 100-year floodplain, striving to optimize essential flood protection while also restoring normal ecosystem function by minimizing the adverse effects of over-drainage. Despite restoration progress, many of the headwater lakes and streams exhibit significant increasing trends in phosphorus and increasing incidences of harmful cyanobacterial blooms, an ominous manifestation in potable water supply. This upward trend is coincident with an increase in the application of wastewater biosolids on cattle pastures in the basins’ western watersheds, and water quality sampling data indicate significant correlations between the cumulative biosolid phosphorus applied within watersheds and runoff phosphorus concentrations. The intensification in application is encouraged in part by a prohibition in the adjacent Okeechobee watershed, elevating the USJR as the next most cost-effective destination for class B biosolids generated in central and south Florida. Current regulations base class B biosolids application rates on crop nitrogen requirements. Phosphorus limits are recommended based on Mehlich-3 extractable P from intermittent soil test result results, a less definitive threshold which, in an environment of biosolids oversupply, could encourage overfertilization with phosphorus and ultimately increased export to surface waters. Additional research is underway to further evaluate the hypothesis linking biosolids application and water quality and to better describe plant available phosphorus from various soil types and biosolids sources, and the modes of phosphorus migration to surface waters.
- The Future of Bubbles: Novel Applications to Linear Oxygen Diffusing Systems
The Future of Bubbles: Novel Applications to Linear Oxygen Diffusing Systems
Shayne Levoy1, Vincent Le Borgne2, Djibril Sy2, and Mario Paris1
1Canadianpond.ca, Knowlton, Quebec, Canada; 2Canadianpond.ca, Sainte-Julie, Quebec, Canada
Linear air diffusion tubing is a technology traditionally used to aerate ponds and lakes, but it has been adapted to create many new applications generally called bubble curtains. Bubble curtains have been used for HAB, and sediment barriers as well as fish deterrence and garbage collection. One key application is sound attenuation. As awareness of the dangers of underwater shockwaves on wildlife increases, we have shown that there are concrete measures that can be taken to reduce sound stress on wildlife.
There are two main phenomena that lead to sound attenuation by fine bubbles. The first is acoustic, which is the energy loss caused by bubbles increasing the compressibility of the water. The other is thermal, in which the compression of the bubbles generates heat in the bubbles by compressing the air which dissipates energy in the form of temperature transfer to the water. Considering that a reduction of 3 dB is equivalent to halving the available energy, the results of our study showed that sound reduction varied from 9 dB with a single bubble line at low frequencies (100 Hz) to 82 dB with a double line at high frequencies (20 000 Hz).
These results show that linear air diffusion tubing can provide high attenuation of underwater sound, depending on the frequency of the source. While attenuation is more pronounced at high frequencies, it is still sufficiently high at low frequencies to lower the impact of human activities on marine animals and ultimately promote marine health and well-being.
- Oxygenation System for Alabama Power’s Logan Martin Hydroelectric Plant
Oxygenation System for Alabama Power’s Logan Martin Hydroelectric Plant
Mark H. Mobley1, James F. Crew2, Paul Gantzer3, Kenneth R. Odom4, R. Jim Ruane5, and Paul J. Wolff6
1Mobley Engineering, Inc., Norris, Tennessee; 2Southern Company Generation, Birmingham, Alabama; 3Gantzer Water Resources Engineering, LLC, Kirkland, Washington; 4Alabama Power, Birmingham, Alabama; 5Reservoir Environmental Management, Chattanooga, Tennessee; 6WolffWare, Norris Tennessee
Logan Martin Dam is located on the Coosa River near Vincent, Alabama. The reservoir area when full is 15,000 acres. The hydroelectric plant has three generating units with a total generating capacity of 128 MW. Each turbine releases 10,000 cubic feet per second. That is 16,000 MGD with all three turbines operating. Alabama Power and Southern Company are working to obtain a new FERC license for the Coosa River Projects. As a part of the relicensing requirements, dissolved oxygen improvements are being made at Weiss, Henry and Logan Martin hydroelectric plants. All three plants have forced air blower systems and Logan Martin has forebay oxygen diffuser system in addition. The oxygen diffuser system can provide enough oxygen to increase the release of two generators by three milligrams per liter of dissolved oxygen. Seven diffusers are located in the forebay extending about a mile upstream of the dam, utilizing the 65-foot water depth to achieve better than 85% oxygen transfer efficiency. This presentation will include a description of the design and construction of the oxygenation system as well as water quality results as available in the reservoir and releases for the first year of operation.
- Not So Fast: Reassessing a Common Rule of Thumb for Destratification System Design
Not so Fast: Reassessing a Common Rule of Thumb for Destratification System Design
Kevin Bierlein, Christine Hawley, and Jean Marie Boyer
Hydros Consulting Inc., Boulder, Colorado
Destratification systems have been used as an in-lake management tool for many decades. They have been applied to limit anoxia and associated water-quality issues, to reduce algae and cyanobacteria growth, and maintain a uniform source water for drinking water treatment.
Diffused air systems are one of the most common types of destratification systems. Although each installation and design is unique, the oft-cited rule of thumb in designing a diffused air destratification system is 1.3 SCFM/acre (9.2 m3/min/km2). This number was originally presented by Lorenzen and Fast (1977) and is often used as a key design parameter. Yet many case studies indicate that management goals may not be achieved even when the system design is based on this rule of thumb.
Since destratification systems often have high capital and operating costs, it is imperative that a system is appropriately designed to avoid wasting limited resources. How can we improve the destratification system design process and increase the likelihood of achieving the desired management goal? Why haven’t design methods progressed beyond this 40-year old rule of thumb? This presentation provides a critical review of how the Lorenzen and Fast rule of thumb was developed, how it has been misapplied over the years, and presents a path forward to improve destratification system design.
- Quantifying Mixing Effectiveness for Water Quality Improvements in Lakes
Quantifying Mixing Effectiveness for Water Quality Improvements in Lakes
Paul Wolff1, Andy Sawyer2, G. Chris Holdren3, and Jim Ruane2
1Wolffware Ltd, Norris, Tennessee; 2Reservoir Environmental Management, Inc., Chattanooga, Tennessee; 3Environmental Consultant, Denver, Colorado
Artificial mixing is an effective in-lake restoration method that can improve water quality by reducing internal nutrient loading and by reducing the severity of cyanobacteria blooms. Mixing can increase hypolimnetic dissolved oxygen concentrations to prevent anoxic release of phosphorus from the sediment to the water column. Mixing can also reduce cyanobacteria blooms through a number of factors that include light limitation because of increased residence depth as well as damaging the cyanobacteria with large changes in hydrostatic pressure. There are a number of techniques used to implement artificial mixing that include: 1) mixing with diffused air; 2) downdraft pumping; and 3) updraft pumping. Determining which technique to implement is challenging because of the wide range of configurations that exist in commercially available systems and the varying claims concerning the performance of these systems.
This presentation will discuss analyses that quantify the effectiveness of different mixing systems. The effectiveness of diffused air circulation is analyzed by coupling a near-field discrete bubble model with CE-QUAL-W2 to understand the far-field effects. A downdraft pumping system is analyzed by coupling a near-field jet model with CE-QUAL-W2. The effectiveness of each approach is quantified by summarizing model results in metrics that include hypolimnetic DO enhancement and thermal structure in the lake. This approach provides a general means to compare the performance of various mixing techniques on an analytical basis to help clarify which system provides the most cost-effective mixing.