sample             ISO_DateTime_Local  ISO_DateTime_UTC      latitude    longitude    depth  SPM_b  
water (LS-SPM-1)   2018-11-08T09:43    2018-11-08T15:43:00Z  43.017835   -87.903521   2      3.62   
water (LS-SPM-2)   2018-11-15T10:27    2018-11-15T16:27:00Z  43.017835   -87.903521   2      0.64   
water (LS-SPM-3)   2018-11-20T10:09    2018-11-20T16:09:00Z  43.017835   -87.903521   2      1.26