Survey of Reservoir Greenhouse gas Emissions file:///P:/PDF_Harvest/ScienceInventory/ScienceInventoiyHarvest/600. Survey of Reservoir Greenhouse gas Emissions Hammertown Lake Water Quality Survey Jake Beaulieu 25 July, 2022 1. Background Between 2020 and 2023 the US Environmental Protection Agency (USEPA) will survey water quality and greenhouse gas (GHG) emissions from 108 reservoirs distributed across the United States (Figure 1). The objective of the research is to estimate the magnitude of GHG emissions from US reservoirs. All reservoirs included in this study were previously sampled by the USEPA during the 2017 National Lakes Assessment (2017 NLA). Data from the 2017 NLA can be found at the EPA website (https://www.epa.gov/national- aquatic-resource-surveys/data-national-aquatic-resource-surveys). Data for Hammertown Lake can be found under SITEJD NLA17_OH-10003. Afield sensor is used to measure chlorophyll a, dissolved oxygen, pH, specific conductivity, water temperature, and turbidity near the water surface at a minimum of 15 locations within each reservoir. Water samples are collected from the deepest site for analysis of nutrients and chlorophyll a. This preliminary report presents water quality results for Hammertown Lake. These data will be included in a formal peer-reviewed publication to be submitted for publication in 2024. Ecoregions Coastal Plains Northern Appalachians Northern Plains Southern Appalachians Southern Plains Temperate Plains Upper Midwest Western Mountains Leaflet (https://leafletjs.com) | Tiles © Esri — Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, Getmapping, Aerogrid, IGN, IGR UPR-EGP, and the GIS User Community Figure 1, Location of the 108 Reservoirs Included in Study. 2. Hammertown Lake Survey Design The Hammertown Lake survey design included 15 sampling sites that were sampled on 2020-08-19. Water chemistry samples were collected from a 15.2m deep site nearby the dam (Figure 2). Click on any of the sites to see the site id, water temperature, pH, turbidity, and dissolved oxygen at the water surface. + Sample sites A ^ sensor sites Leaflet (https://leafletjs.com) | Tiles © Esri — Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, Getmapping, Aerogrid, IGN, IGP, [g UPR-EGP, and the GIS User Community 1 of 5 12/14/2022, 3:22 PM ------- Survey of Reservoir Greenhouse gas Emissions file:///P:/PDF_Harvest/ScienceInventory/ScienceInventoiyHarvest/600. Figure 2. Location of the 15 sampling sites in Hammertown Lake. 3. Lake Disturbance and Trophic Status Lakes are often classified according to their trophic state. There are four trophic state categories that reflect nutrient availability and plant growth within a lake. A eutrophic lake has high nutrients and high algal and/or macrophyte plant growth. An oligotrophic lake has low nutrient concentrations and low plant growth. Mesotrophic lakes fall somewhere in between eutrophic and oligotrophic lakes and hypereutrophic lakes have very high nutrients and plant growth. Lake trophic state is typically determined by a wide variety of natural factors that control nutrient supply climate, and basin morphometry. A metric commonly used for defining trophic state is the concentration of chlorophyll a, an indicator of algae abundance, in the water column. Chlorophyll a concentration was 2 ug/L during the sampling, indicating the lake was oligotrophic. Trophic State Classification Analyte Oligotrophic Mesotrophic Eutrophic Hypereutrophic chlorophyll a (ug/L) <=2 >2 and <=7 >7 and <=30 >30 In addition to classifying lakes by trophic status, lakes can be classified by degree of disturbance relative to undisturbed lakes (i.e. reference lakes) within the ecoregion. Degree of disturbance can be based on a wide variety of metrics, but here we use nutrients (total phosphorus (tp), total nitrogen (tn)), suspended sediment (turbidity), chlorophyll a, and dissolved oxygen (do). All lake disturbance values are least disturbed. Chemical Condition Indicators Measured at Water Chemistry Site Threshold Values Observed Values parameter units least disturbed moderately disturbed most disturbed concentration status do mg/l >5 >3 it <5 <3 8 least disturbed turbidity NTU <2.83 >2.83 t St <3.94 >3.94 1.00 least disturbed tp ug/l <19 >19 i A CO CO >33 11 least disturbed tn ug/l <309 >309 t st <407 >407 142 least disturbed chlorophyll a ug/l <5.23 CO Csl lo A St <11.5 >11.5 2.0 least disturbed 4. Within-lake Spatial Patterns A field sensor was used to measure water temperature, pH, dissolved oxygen, and turbidity near the water surface at all sampling sites. Data are reported in figures and tables below. Hover the curser over any point in the figures 2 of 5 12/14/2022, 3:22 PM ------- Survey of Reservoir Greenhouse gas Emissions file:///P:/PDF_Harvest/ScienceInventory/ScienceInventoiyHarvest/600. to reveal the sitelD corresponding to the adjacent data table. Alternatively, click on any row in the data table to reveal the location of the sampling site on the map. Turbidity is highest near the river inflows, but decreases toward the dam as water velocity decreases and suspended sediment drops out of the water column. Water temperature, dissolved oxygen and pH are relatively constant throughout the reservoir at 0.1m depth. water sitelD temp 1 27.71 2 27.29 3 27.45 4 26.96 5 27.51 6 27.25 7 27.64 8 27.05 9 27.38 10 27.51 11 27.58 12 27.55 13 27.15 14 27.55 15 27.2 sitelD pH 1 7.83 2 7.83 3 7.97 4 7.87 5 7.78 6 7.86 7 7.7 8 7.8 9 7.9 10 8.09 11 7.91 12 7.72 13 7.81 14 7.95 15 7.91 Water iTemp. I(°C) Leaflet (https://leafletjs.com) | Tiles © Esri — Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, Getmapping, Aerogrld, IGN, IGP, UPR-EGP, and the GIS UserCommunity Leaflet (https://leafletjs.com) | Tiles © Esri — Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, Getmapping, Aerogrid, IGN, IGP, UPR-EGP, and the GIS User Community 3 of 5 12/14/2022, 3:22 PM ------- |