This Data release includes time series data collected at Operable Unit 2, Area 8, at Naval Base Kitsap, Keyport, WA. Groundwater elevations and water quality parameters in five monitoring wells, along with tide levels in Port Orchard Bay, were monitored every 15 minutes during a 3-week duration. Time series data were collected from October 24, 2017, to November 16, 2017, a period that included neap and spring tides. Field deployment details and quality assurance methods are included in Open-File Report 2018-1082, “Analysis of Groundwater Response to Tidal fluctuations, Operable Unit 2, Area 8, Naval Base Kitsap, Keyport, Washington”. Tidal altitudes were adjusted by an estimated offset to be approximately comparable to NAVD88 groundwater altitudes. Tide and groundwater altitudes are referenced to the North American Vertical Datum 1988 (NAVD88). Tide and groundwater horizontal datum for latitude and longitude were referenced to North American Datum 1983 (NAD83). Water parameters included in each MW-#_Time_Series_Data.csv file are temperature, in degrees Celsius (C); water level altitude, in feet (ft) above NAVD88; specific conductivity, in microsiemens per centimeter (µS/cm); and salinity, in practical salinity units (PSU). Parameters in the file Tide_Level_Time_Series_Data.csv are temperature, in degrees C, and tide level, in ft approximately above NAVD88. An Internet link to the National Water Information System (NWIS) is provided on this landing page along with an attached table of monitoring well and tide information including the well ID number (Keyport_OU2_Area8_Monitoring _Site_ID.csv).