Date:06-28-2024STATE OF CALIFORNIA 
LAST AND NEXT SAMPLE REPORT
SYSTEM NO.:4100540SYSTEM NAME:OKU INCORPORATEDCOUNTY:SAN MATEO 
SOURCE NO.:All SourcesSOURCE NAME:N/ASOURCE CLASS:N/ASTATUS:N/A



Click to hide / show columns: PS Codes | Group Name | Analyte Number | Analyte Name | Detected Level |Less Than | RL | Unit | MCL | DLR | Last Sampled | Frequency | Next Due | Notes

PS Codes Group Name Analyte Number Analyte Name Results Unit MCL DLR Last Sampled Frequency Next Due Notes
Detected Level Less Than RL
CA4100540_005_005 SECONDARY/GP-202506 1928 ALKALINITY, BICARBONATE 233.000 5.000 MG/L 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1919 CALCIUM 27.000 0.200 MG/L 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1929 ALKALINITY, CARBONATE < 5.000 MG/L 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1017 CHLORIDE 340.000 20.000 MG/L 500 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1905 COLOR 750.000 100.000 UNITS 15 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1022 COPPER, FREE < 10.000 UG/L 1000 50 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 2905 FOAMING AGENTS (SURFACTANTS) 0.051 0.025 MG/L .5 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1915 HARDNESS, TOTAL (AS CACO3) 120.000 1.300 MG/L 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1021 HYDROXIDE AS CALCIUM CARBONATE < 5.000 MG/L 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202705 1028 IRON 16000.000 100.000 UG/L 300 05-30-2024 36 2027/05
CA4100540_005_005 SECONDARY/GP-202506 1031 MAGNESIUM 13.000 0.200 MG/L 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202408 1032 MANGANESE 2000.000 20.000 UG/L 50 05-30-2024 3 2024/08
CA4100540_005_005 SECONDARY/GP-202506 1920 ODOR < 1.000 TON 3 1 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1925 PH 7.390 pH 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1050 SILVER < 10.000 UG/L 100 10 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1052 SODIUM 250.000 1.000 MG/L 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1064 CONDUCTIVITY @ 25 C UMHOS/CM 1280.000 10.000 UMHO/CM 1600 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1055 SULFATE 0.240 0.200 MG/L 500 .5 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1930 TDS 824.000 10.000 MG/L 1000 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 0100 TURBIDITY 300.000 0.100 NTU 5 .1 06-02-2022 36 2025/06
CA4100540_005_005 SECONDARY/GP-202506 1095 ZINC < 50.000 UG/L 5000 50 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202303 1002 ALUMINUM < 50.000 UG/L 1000 50 12-21-2022 3 2023/03 DUE NOW
CA4100540_005_005 INORGANIC-202506 1074 ANTIMONY, TOTAL < 6.000 UG/L 6 6 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202506 1005 ARSENIC 7.300 2.000 UG/L 10 2 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-203106 1094 ASBESTOS < 0.200 MFL 7 .2 06-02-2022 108 2031/06
CA4100540_005_005 INORGANIC-202506 1010 BARIUM < 100.000 UG/L 1000 100 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202506 1075 BERYLLIUM, TOTAL < 1.000 UG/L 4 1 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202506 1015 CADMIUM < 1.000 UG/L 5 1 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202506 1020 CHROMIUM < 10.000 UG/L 50 10 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202506 1024 CYANIDE < 5.000 UG/L 150 100 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202506 1025 FLUORIDE 0.520 0.200 MG/L 2 .1 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202506 1035 MERCURY < 0.020 UG/L 2 1 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202506 1036 NICKEL < 10.000 UG/L 100 10 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202512 1039 PERCHLORATE < 1.000 UG/L 6 2 12-21-2022 36 2025/12
CA4100540_005_005 INORGANIC-202506 1045 SELENIUM < 5.000 UG/L 50 5 06-02-2022 36 2025/06
CA4100540_005_005 INORGANIC-202506 1085 THALLIUM, TOTAL < 1.000 UG/L 2 1 06-02-2022 36 2025/06
CA4100540_005_005 NITRATE/NITRITE-202412 1040 NITRATE 0.190 0.100 MG/L 10 .4 12-07-2023 12 2024/12
CA4100540_005_005 NITRATE/NITRITE-202506 1041 NITRITE < 0.200 MG/L 1 .4 06-02-2022 36 2025/06
CA4100540_005_005 RADIOLOGICAL-202402 4109 GROSS ALPHA PARTICLE ACTIVITY 5.450 +/- 2.100 2.400 PCI/L 15 3 02-24-2015 108 2024/02 DUE NOW
CA4100540_005_005 REGULATED VOC-202506 2981 1,1,1-TRICHLOROETHANE < 0.500 UG/L 200 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2988 1,1,2,2-TETRACHLOROETHANE < 0.500 UG/L 1 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2985 1,1,2-TRICHLOROETHANE < 0.500 UG/L 5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2978 1,1-DICHLOROETHANE < 0.500 UG/L 5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2977 1,1-DICHLOROETHYLENE < 0.500 UG/L 6 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2378 1,2,4-TRICHLOROBENZENE < 0.500 UG/L 5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2968 O-DICHLOROBENZENE < 0.500 UG/L 600 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2980 1,2-DICHLOROETHANE < 0.500 UG/L .5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2983 1,2-DICHLOROPROPANE < 0.500 UG/L 5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202512 2413 1,3-DICHLOROPROPENE < 0.500 UG/L .5 .5 12-21-2022 36 2025/12
CA4100540_005_005 REGULATED VOC-202506 2969 P-DICHLOROBENZENE < 0.500 UG/L 5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2990 BENZENE < 0.500 UG/L 1 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2982 CARBON TETRACHLORIDE < 0.500 UG/L .5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2380 CIS-1,2-DICHLOROETHYLENE < 0.500 UG/L 6 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2964 DICHLOROMETHANE < 0.500 UG/L 5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2992 ETHYLBENZENE < 0.500 UG/L 300 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2251 METHYL TERT-BUTYL ETHER < 0.500 UG/L 13 3 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2989 CHLOROBENZENE < 0.500 UG/L 70 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2996 STYRENE < 0.500 UG/L 100 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2987 TETRACHLOROETHYLENE < 0.500 UG/L 5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2991 TOLUENE < 0.500 UG/L 150 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2979 TRANS-1,2-DICHLOROETHYLENE < 0.500 UG/L 10 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2984 TRICHLOROETHYLENE < 0.500 UG/L 5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2218 TRICHLOROFLUOROMETHANE < 0.500 UG/L 150 5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2904 TRICHLOROTRIFLUOROETHANE < 0.500 UG/L 1200 10 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2976 VINYL CHLORIDE < 0.500 UG/L .5 .5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED VOC-202506 2955 XYLENES, TOTAL < 0.500 UG/L 1750 0.5 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED SOC-202506 2414 1,2,3-TRICHLOROPROPANE < 0.005 UG/L 0.005 06-02-2022 36 2025/06
CA4100540_005_005 REGULATED SOC-202712 2105 2,4-D < 10.000 UG/L 70 10 12-16-2018 108 2027/12
CA4100540_005_005 REGULATED SOC-202402 2050 ATRAZINE < 0.500 UG/L 1 .5 02-24-2015 108 2024/02 DUE NOW
CA4100540_005_005 REGULATED SOC-202402 2037 SIMAZINE < 1.000 UG/L 4 1 02-24-2015 108 2024/02 DUE NOW
CA4100540_006_006 SECONDARY/GP-202406 1028 IRON < 100.000 UG/L 300 05-30-2024 1 2024/06 DUE NOW
CA4100540_006_006 SECONDARY/GP-202406 1032 MANGANESE < 20.000 UG/L 50 05-30-2024 1 2024/06 DUE NOW
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2943 BROMODICHLOROMETHANE < 0.500 UG/L 1 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2942 BROMOFORM < 0.500 UG/L 1 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2941 CHLOROFORM 1.800 0.500 UG/L 1 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2454 DIBROMOACETIC ACID < 0.130 UG/L 1 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2944 DIBROMOCHLOROMETHANE < 0.500 UG/L 1 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2451 DICHLOROACETIC ACID < 0.130 UG/L 1 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2456 TOTAL HALOACETIC ACIDS (HAA5) < 0.130 UG/L 60 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2453 MONOBROMOACETIC ACID < 0.130 UG/L 1 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2450 MONOCHLOROACETIC ACID < 0.270 UG/L 2 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2950 TTHM 1.800 0.500 UG/L 80 09-28-2023 36 2026/09
CA4100540_DST_900 DISINFECTION BYPRODUCTS-202609 2452 TRICHLOROACETIC ACID < 0.130 UG/L 1 09-28-2023 36 2026/09
PS Codes Group Name Analyte Number Analyte Name Detected Level Less Than RL Unit MCL DLR Last Sampled Frequency Next Due Notes

RL – Reporting Level means the level to which the laboratory reported the presence of an analyte. For radionuclides, Reporting Level is the MDA95.

DLR – Detection Limit for purposes of Reporting (DLR) means the designated minimum level at or above which any analytical finding of a contaminant in drinking water resulting from monitoring required under Chapter 15 of Title 22 shall be reported to the State Board (California Code of Regulations Section § 64400.34)

For addtional definitions, please refer to our data dictionary.