This is a rebuild of Drinking Water Watch and not yet the official record. Use the agency’s current Drinking Water Watch for anything you need to rely on.
Analytes tested for
MS0700011 , Town of Walnut
Town of Walnut has been analysed for 59 analytes.
This is what has been looked for, not what has been found. Which of them have been detected, and when, is on the sample results page.
The agency also publishes one analyte list across every system it serves. That list carries no results and no counts, and it leaves out coliform and the other microbiological analytes — which this page does not.
57 of these are chemical, radiological or water-quality analytes, and their results are on the chemical and radiological samples page — which counts 57, not 59, for that reason. The other 2 — Coliform (TCR) and E. Coli — are organisms, and their records live with the coliform and microbial samples.
| Analyte | Kind | Results on record | Last collected |
|---|---|---|---|
| 1,1,1-Trichloroethane 2981 | Organic Chemical | 14 | Sep 28, 2022 |
| 1,1,2-Trichloroethane 2985 | Organic Chemical | 14 | Sep 28, 2022 |
| 1,1-Dichloroethylene 2977 | Organic Chemical | 14 | Sep 28, 2022 |
| 1,2,4-Trichlorobenzene 2378 | Organic Chemical | 14 | Sep 28, 2022 |
| 1,2-Dichloroethane 2980 | Organic Chemical | 14 | Sep 28, 2022 |
| 1,2-Dichloropropane 2983 | Organic Chemical | 14 | Sep 28, 2022 |
| Antimony, Total 1074 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Arsenic 1005 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Barium 1010 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Benzene 2990 | Organic Chemical | 14 | Sep 28, 2022 |
| Beryllium, Total 1075 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Bromodichloromethane 2943 | Organic Chemical | 13 | Jun 15, 2026 |
| Bromoform 2942 | Organic Chemical | 13 | Jun 15, 2026 |
| Cadmium 1015 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Carbon Tetrachloride 2982 | Organic Chemical | 14 | Sep 28, 2022 |
| Chlorobenzene 2989 | Organic Chemical | 14 | Sep 28, 2022 |
| Chloroform 2941 | Organic Chemical | 13 | Jun 15, 2026 |
| Chromium 1020 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Cis-1,2-Dichloroethylene 2380 | Organic Chemical | 14 | Sep 28, 2022 |
| Coliform (TCR) 3100 | Organism | 574 | Jul 22, 2026 |
| Combined Radium (-226 & -228) 4010 | Radionuclide | 10 | Jul 13, 2012 |
| Combined Uranium 4006 | Radionuclide | 8 | Oct 6, 2021 |
| Copper, Free 1022 | Inorganic Chemical | 93 | Aug 9, 2023 |
| Cyanide 1024 | Inorganic Chemical | 20 | Nov 18, 2025 |
| Dibromoacetic Acid 2454 | Organic Chemical | 13 | Jun 15, 2026 |
| Dibromochloromethane 2944 | Organic Chemical | 13 | Jun 15, 2026 |
| Dichloroacetic Acid 2451 | Organic Chemical | 13 | Jun 15, 2026 |
| Dichloromethane 2964 | Organic Chemical | 14 | Sep 28, 2022 |
| E. Coli 3014 | Organism | 180 | Jul 22, 2026 |
| Ethylbenzene 2992 | Organic Chemical | 14 | Sep 28, 2022 |
| Fluoride 1025 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Gross Alpha, Incl. Radon & U 4002 | Radionuclide | 10 | Jul 13, 2012 |
| Lead 1030 | Inorganic Chemical | 93 | Aug 9, 2023 |
| Mercury 1035 | Inorganic Chemical | 20 | Sep 24, 2025 |
| Monobromoacetic Acid 2453 | Organic Chemical | 13 | Jun 15, 2026 |
| Monochloroacetic Acid 2450 | Organic Chemical | 13 | Jun 15, 2026 |
| Nickel 1036 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Nitrate 1040 | Inorganic Chemical | 43 | Jul 16, 2026 |
| Nitrate-Nitrite 1038 | Inorganic Chemical | 43 | Jul 16, 2026 |
| Nitrite 1041 | Inorganic Chemical | 43 | Jul 16, 2026 |
| O-Dichlorobenzene 2968 | Organic Chemical | 14 | Sep 28, 2022 |
| P-Dichlorobenzene 2969 | Organic Chemical | 14 | Sep 28, 2022 |
| Radium-226 4020 | Radionuclide | 10 | Jul 13, 2012 |
| Radium-228 4030 | Radionuclide | 10 | Jul 13, 2012 |
| Selenium 1045 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Sodium 1052 | Inorganic Chemical | 5 | Jul 16, 2026 |
| Styrene 2996 | Organic Chemical | 14 | Sep 28, 2022 |
| Sulfate 1055 | Inorganic Chemical | 4 | Mar 31, 2004 |
| Tetrachloroethylene 2987 | Organic Chemical | 14 | Sep 28, 2022 |
| Thallium, Total 1085 | Inorganic Chemical | 20 | Mar 31, 2025 |
| Toluene 2991 | Organic Chemical | 14 | Sep 28, 2022 |
| Total Haloacetic Acids (Haa5) 2456 | Organic Chemical | 18 | Jun 15, 2026 |
| Trans-1,2-Dichloroethylene 2979 | Organic Chemical | 14 | Sep 28, 2022 |
| Trichloroacetic Acid 2452 | Organic Chemical | 13 | Jun 15, 2026 |
| Trichloroethylene 2984 | Organic Chemical | 14 | Sep 28, 2022 |
| TTHM 2950 | Organic Chemical | 17 | Jun 15, 2026 |
| Uranium-238 4009 | Radionuclide | 2 | May 1, 2006 |
| Vinyl Chloride 2976 | Organic Chemical | 14 | Sep 28, 2022 |
| Xylenes, Total 2955 | Organic Chemical | 14 | Sep 28, 2022 |
A result is one laboratory analysis for one analyte on one sample, whether or not anything was found. Counts cover every Accepted or Validated result on record, with no date range applied.
What an analyte is
“Analytes are contaminants and other elements (some of which are not necessarily contaminants), for which the drinking water is being analyzed.”
From the help text published with these pages.