U.S. Army Corps of Engineers - Little Rock District Pertinent Data File for the 2020 Low Dissolved Oxygen (DO) Season --------------------------------------------- 28May - All water quality gages are installed except left bank at Norfork. 03Jun - 18 tons of LOX deliverd. 23.4 tons onhand. 07Jun - 21.1 tons of LOX delivered. 44.5 tons onhand. 10Jun - Temp spike bleow Beaver during spill. USGS checked gage. Tail water temp was around 75 deg. 16Jun - Table Rock tailwater DO values dropped from over 8 ppm to less than 5 ppm in less than a day, with no generation. USACE assumes this is erroneous data. USACE contacted USGS MO and they will be servicing the gage Thursday morning. 18Jun - USGS MO staff cleaned and calibrated the Table Rock tailwater DO sensor and the School of the Ozarks DO sensor. 19Jun - Table Rock blocked open vacuum breaker vents. 22Jun - Norfork blocked open vacuum breaker vents. 26Jun - June D.O. profiles delivered 2020 I.D.O. VS 2019 I.D.O Beaver: 22Jun2020 7.60 VS 8.06 24Jun2019 Table Rock: 23Jun2020 5.46 VS 6.67 25Jun2019 Bull Shoals: 23Jun2020 7.82 VS 8.30 26Jun2019 Norfork: 24Jun2020 5.55 VS 6.14 26Jun2019 Greers Ferry: 25Jun2020 7.04 VS 7.87 27Jun2019 22Jul - LOX system is online. 29Jul - Table Rock RMGR 100% nameplate (200 MW) 31Jul - Table Rock RMGR 90% nameplate (200 MW) 31Jul - Norfork RMGR 95% nameplate (76 MW) 31Jul - 1.2 tons LOx injected in past 24 hrs; 43.6 tons on hand 06Aug - Norfork RMGR 90% nameplate (72 MW) 07Aug - July D.O. profiles delivered 2020 I.D.O. VS 2019 I.D.O Table Rock: 04Aug2020 2.36 VS 4.21 30Jul2019 Bull Shoals: 28Jul2020 6.03 VS 6.53 31Jul2019 Norfork: 28Jul2020 2.66 VS 3.58 31Jul2019