Susquehanna University Scholarly Commons

Senior Scholars Day

Apr 28th, 12:00 AM - 12:00 AM

The Impact of Lake Stratification on Biogeochemical Cycling and Downstream Water Quality: Case Study of Faylor and Walker Lakes in Snyder County, PA

Trent Millum

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Part of the Biogeochemistry Commons, Hydrology Commons, and the Water Resource Management Commons

Millum, Trent, "The Impact of Lake Stratification on Biogeochemical Cycling and Downstream Water Quality: Case Study of Faylor and Walker Lakes in Snyder County, PA" (2020). Senior Scholars Day. 17. https://scholarlycommons.susqu.edu/ssd/2020/posters/17

This Event is brought to you for free and open access by Scholarly Commons. It has been accepted for inclusion in Senior Scholars Day by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. Trent Millum and Ahmed Lachhab, Earth and Environmental Sciences, Susquehanna University, Selinsgrove, PA 17870 Introduction Results and Discussion

9/7/2019 9/26/2019 10/16/2019 T(oC) T(oC) T(oC) • Impacts of smaller reservoirs on streams is infrequently studied and inconclusive 10 12 14 16 18 20 22 24 26 10 12 14 16 18 20 22 24 26 10 12 14 16 18 20 22 24 26 0 scientifically. 0 0 • Throughout the U.S. dams were constructed with great uncertainty surrounding their 0.4 0.4 0.4 0.8 0.8 0.8 1 environmental impacts. 1.2 1.2 1.2 1.6 1.6 1.6 • The impacts on the downstream of a reservoir are determined based on the size, shape, 2 2 2 2 2.4 2.4 2.4 and spillway structure. 2.8 2.8 2.8 3.2 3.2 3.2 Depth (m) Depth • Primary effects of reservoirs on stream systems include increased water temperature, 3.6 Depth (m) Depth 3.6 3.6 4 + decreased sediment carrying capacity, reduced dissolved oxygen, and biological 4 4 Figure 5. NH4 concentrations at each site compared for 17 different data points. Depth (m) Depth 3 4.4 4.4 4.4 impairment. 4.8 4.8 4.8 • Seasonal thermal and chemical stratification occur in deeper reservoirs causing 5.2 5.2 5.2 5.6 5.6 5.6 6 temperature and dissolved oxygen to decrease which result in highly reducing chemical 6 6 6.4 6.4 6.4 4 6.8 conditions at the bottom. 6.8 6.8 7.2 - + 7.2 7.2 7.6 • In reducing conditions, denitrification or DNRA reduce NO3 to NH4 or N2, and 7.6 7.6 8 2- 5 8 8 sulfur, SO4 is consumed and H2S is formed by anaerobic microbes. 8.4 8.4 8.4 8.8 8.8 • The study herein compared two small reservoirs (Walker and Faylor Lakes) and showed 8.8 how stratification affects biogeochemical cycling and impacts the downstream water quality. Figure 2: Thermal stratification in Walker Lake (data collected from 9/6/20 – 10/31/20) WL Profile WL Profile DO WL Profile NH4+ & SO42- • Physical, chemical, and biological results showed that Walker lake is causing more AMMONIUM (MG/L) TO (OC) 12 17 22 27 -1 4 9 impairment to its downstream water due to its stratification, while Faylor lake has less 0 0 0 0 0 effects. -1 -1 -1 -1 -1

-2 Site Description -2 -2 -2 -2

-3 -3 -3 -3 -3 -4 -4 -4 -4 -4

DEPTH (M) DEPTH -5 DEPTH (M) DEPTH (M) DEPTH (M) DEPTH DEPTH (M) DEPTH -5 -5 -5 -5 Figure 6. BOD5 and WQI for all four sites, demonstrating the declining Figure 7. Boxplots displaying the relationship -6 water quality downstream of Walker Lake dam when compared to between Temperature (reservoir stratification), -6 -6 -6 -6 - + -7 upstream of Walker and Faylor Lake sites. NO3 and NH4 at DW site.

-7 -7 -7 -7 -8 • Data showed a seasonal thermal stratification in Walker Lake showing distinct layers of water -8 -8 -8 -8 -9 -200 0 200 400 600 0 2 4 6 8 -1 4 9 with differing characteristics (Figure 2) DO (MG/L) KE, TDS & ORP SULFATE (MG/L) • Thermocline detected to be around 6 meters deep and shifts downward prior to the lake turnover T(oC) Ke(mS/cm) TDS(mg/L) ORP (mV) DO(mg/l) Sulfate(mg/L) Ammonium (Figures 2 and 3) + 2- From September to November, as air temperatures cool down, the stratified Walker Lake begins Figure 3: Physical and Chemical data including T, TDS, ORP, Ke, DO, NH4 and SO4 demonstrating lake stratification in • Walker Lake (data collected on 10/4/2019) to mix again and turnover, demonstrated by the decreasing temperature range between the surface of the lake and the bottom (Figure 4). • Stratification causes depletion of DO around 5 meters, leading to reducing chemical conditions 2- + that decrease SO4 and increase NH4 concentrations (Figures 3, 4 and 5). • Domino effect: Thermal stratification and excessive algal blooms lead to depleted DO, which + lead to the formation of toxic chemicals (NH4 and H2S). The bottom release discharge decrease the water quality at the downstream site. Faylor Lake is homogeneously mixed and has a neutral impact. + • Increased NH4 concentrations downstream of Walker Lake to toxic levels greater than 2 mg/L as compared to negligible concentrations upstream of both dams and downstream of Faylor Figure 1. Map of Middle Creek Watershed and sample sites on the west and north branches of Middle reek showing upstream Lake (Figure 5). and downstream of each lake including the site in Walker Lake. • Significant biological impairment of the macroinvertebrates indicated downstream of Walker Lake due to 0% EPT, a pollution-tolerant community, high Hillsenhoff Index scores, and low Methods diversity values (Table 1).

• BOD5 increase downstream of Walker Lake throughout the summer that follows the pattern of

O decreasing values for the WQI, indicating significant organic pollution caused by depletion of YSI Multimeter T , TDS, Ke, DO, pH, ORP oxygen and overgrowth of algae in the reservoir (Figure 6). Physical DO Probe BOD5 Water Grab Sample Figure 4: Complete temperature range of water in Walker Lake at each sampling point (surface to 8.4 m depth) from 9/6/20 – 10/31/20 Conclusions Spectrophotometer COD • Walker Lake is deep enough, especially near the dam, to maintain stratification. Table 1. Data and analysis of benthic macroinvertebrate samples from each site, including data from indices such as the; Hilsenhoff - 2- • Physical, chemical, and biological results of lake stratification along with the reservoir design are NO2-, NO3 , F, Cl, Br, SO4 , Index, Shannon Diversity Index, and EPT index. Anions 3− PO4 Index UW DW UF DF causing impairment downstream. Water Grab Sample Ion Chromatography System + + 2+, 2+ + Taxa Richness 11 8 7 8 • Thermal Stratification leads to a series of changes that cause oxygen depletion and high levels of Chemical Cations Na , K , Mg Ca , NH4 HI Score 4.176 6.104 4.166 4.578 + Grab samples from Walker NH4 to be released downstream with other harmful chemicals and organic pollution leading to a Lake % EPT (Species Intolerance-Family Level) Shannon Diversity Index 2.063 0.875 1.405 1.555 Shannon Diversity Evenness 0.860 0.421 0.722 0.748 high BOD5 Water Quality based on Hilsenhoff Index Very Good Fairly Poor Very Good Good Biological Kick Sampling & Picking Hilsenhoff Index (Index of Biotic • Small reservoirs can have negative environmental impacts on their stream systems, depending on Integrity) Organic Pollution (Hilsenhoff Index) Slight Organic Pollution Substantial Pollution Likely Slight Organic Pollution Some Organic Pollution Problem % EPT 41% 0 55% 22% their size, shape and spillway structure. Shannon Diversity Index Dominant Taxa Tipulidae Chironomidae Hydropsychidae Gammaridae % Dominant Taxa 17% 78% 38% 36% % Pollution Tolerant Taxa 14% 93% 3% 8% References 1Poff, N. L., & Hart, D. D. (2002). How dams vary and why it matters for the emerging science of dam removal. Bioscience, 52(8), 659-668. 2Brandt, S. (2000). Classification of geomorphological effects downstream of dams. Catena, 40(4), 375–401. Representation of the various processes to investigate each of the relevant parameters in this study. Not displayed 3Kegley, S. E., & Andrews, J. (1998). The chemistry of water. Sausalito, Calif: University Science Books. Figure 2. 4 Boehrer, B., & Schultze, M. (2008). Stratification of lakes. Reviews of Geophysics, 46(2). is the WQI. 5Nizzoli, D., Carraro, E., Nigro, V., & Viaroli, P. (2010). Effect of organic enrichment and thermal regime on denitrification and dissimilatory nitrate reduction to ammonium (DNRA) in hypolimnetic sediments of two lowland lakes. Water Research, 44(9), 2715–2724.