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.
Chemical and radiological sample results
MS0140010 , Town of Lyon
26 of the 58 analytes this system has been tested for have been detected at least once, across 379 samples on record.
The other 32 were tested for and never found. An analyte is counted here if any result on record measured it, so this covers the whole history and not the samples listed below.
Across all 379 samples on record, detections range from September 28, 1993 to September 30, 2025. These figures cover the whole record.
What counts as a non-detect is defined in the help: Less than Indicator. This system’s violations.
What has been detected, ever
Every analyte measured above its reporting level at any point in this system’s record, most often detected first. This is not limited to the samples listed below.
| Analyte | Kind | Detected in | First detected | Last detected |
|---|---|---|---|---|
| TTHM 2950 | Organic Chemical | 106 of 112 results | Sep 15, 2004 | Sep 24, 2025 |
| Total Haloacetic Acids (Haa5) 2456 | Organic Chemical | 100 of 107 results | Sep 15, 2004 | Sep 24, 2025 |
| Copper, Free 1022 | Inorganic Chemical | 76 of 77 results | Sep 28, 1993 | Sep 30, 2025 |
| Bromodichloromethane 2943 | Organic Chemical | 75 of 79 results | May 16, 2006 | May 19, 2020 |
| Dibromochloromethane 2944 | Organic Chemical | 75 of 79 results | May 16, 2006 | May 19, 2020 |
| Bromoform 2942 | Organic Chemical | 74 of 79 results | May 16, 2006 | May 19, 2020 |
| Dibromoacetic Acid 2454 | Organic Chemical | 72 of 75 results | Oct 11, 2007 | May 19, 2020 |
| Chloroform 2941 | Organic Chemical | 72 of 79 results | May 16, 2006 | May 19, 2020 |
| Trichloroacetic Acid 2452 | Organic Chemical | 66 of 75 results | Oct 11, 2007 | May 19, 2020 |
| Dichloroacetic Acid 2451 | Organic Chemical | 63 of 75 results | Apr 28, 2008 | May 19, 2020 |
| Lead 1030 | Inorganic Chemical | 52 of 77 results | Sep 28, 1993 | Sep 30, 2025 |
| Monobromoacetic Acid 2453 | Organic Chemical | 35 of 75 results | Jan 29, 2008 | Aug 15, 2019 |
| Monochloroacetic Acid 2450 | Organic Chemical | 13 of 75 results | Nov 18, 2009 | May 19, 2020 |
| Arsenic 1005 | Inorganic Chemical | 12 of 12 results | Apr 9, 2002 | Mar 12, 2025 |
| Barium 1010 | Inorganic Chemical | 12 of 12 results | Apr 9, 2002 | Mar 12, 2025 |
| Fluoride 1025 | Inorganic Chemical | 12 of 12 results | Apr 9, 2002 | Mar 12, 2025 |
| Selenium 1045 | Inorganic Chemical | 12 of 12 results | Apr 9, 2002 | Mar 12, 2025 |
| Chromium 1020 | Inorganic Chemical | 8 of 12 results | Apr 9, 2002 | May 11, 2022 |
| Xylenes, Total 2955 | Organic Chemical | 8 of 33 results | Jan 12, 2004 | Apr 20, 2021 |
| Thallium, Total 1085 | Inorganic Chemical | 2 of 12 results | Feb 28, 2005 | Apr 22, 2020 |
| Gross Alpha Particle Activity 4109 | Radionuclide | 2 of 6 results | Sep 28, 2011 | Sep 12, 2012 |
| Nitrite 1041 | Inorganic Chemical | 1 of 20 results | Jan 10, 2022 | Jan 10, 2022 |
| Sodium 1052 | Inorganic Chemical | 1 of 1 result | Sep 25, 2019 | Sep 25, 2019 |
| Gross Alpha, Excl. Radon & U 4000 | Radionuclide | 1 of 2 results | Sep 28, 2011 | Sep 28, 2011 |
| Nickel 1036 | Inorganic Chemical | 1 of 12 results | Mar 24, 2008 | Mar 24, 2008 |
| Mercury 1035 | Inorganic Chemical | 1 of 12 results | Feb 28, 2005 | Feb 28, 2005 |
No date range is applied: this list draws on every sample on record. Show the last two years only.
The most recent samples, result by result
The table below lists 41–50 of 379 samples, newest first — collected April 11, 2022 to July 20, 2022. The summary above covers all 379.
25 results from the 10 samples listed here: 17 detected, 8 not detected. Across the whole record it is 952 of 1,981. A sample is analysed for many analytes at once, so one sample appears on as many rows as it had results.
We withheld the location of 2 sampling points below. The location on record identifies a private home, and we do not publish those. That is our decision, not the agency’s. The sampling point, its type and every result taken there are published unchanged.
| Result | Analyte | Monitoring period |
|---|---|---|
|
||
| 11.1 ug/l , sample collected Jul 20, 2022 12:05, sampling point SM1 | TTHM 2950 EPA method 524.2 | Jul 1, 2022 – Sep 30, 2022 |
|
||
| 0.606 mg/l , sample collected Jun 15, 2022 07:02, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| 1.6 ug/l , sample collected Jun 15, 2022 07:02, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
|
||
| 0.663 mg/l , sample collected Jun 15, 2022 07:04, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| Not detected below 0.5 ug/l Minimum Reporting Level , sample collected Jun 15, 2022 07:04, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
|
||
| 0.596 mg/l , sample collected Jun 15, 2022 07:10, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| 1.4 ug/l , sample collected Jun 15, 2022 07:10, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
|
||
| 0.0077 mg/l , sample collected Jun 15, 2022 06:58, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| Not detected below 0.5 ug/l Minimum Reporting Level , sample collected Jun 15, 2022 06:58, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
|
||
| 0.852 mg/l , sample collected Jun 15, 2022 07:40, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| 1.8 ug/l , sample collected Jun 15, 2022 07:40, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
|
||
| 0.0016 mg/l , sample collected May 11, 2022 12:15, sampling point TF101 | Arsenic 1005 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| 0.0089 mg/l , sample collected May 11, 2022 12:15, sampling point TF101 | Barium 1010 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 11, 2022 12:15, sampling point TF101 | Cadmium 1015 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| 0.0006 mg/l , sample collected May 11, 2022 12:15, sampling point TF101 | Chromium 1020 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| 0.353 mg/l , sample collected May 11, 2022 12:15, sampling point TF101 | Fluoride 1025 EPA method QC 10-109-12-2-A | Jan 1, 2020 – Dec 31, 2022 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 11, 2022 12:15, sampling point TF101 | Mercury 1035 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 11, 2022 12:15, sampling point TF101 | Nickel 1036 EPA method 200.8 | Not recorded |
| 0.0054 mg/l , sample collected May 11, 2022 12:15, sampling point TF101 | Selenium 1045 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 11, 2022 12:15, sampling point TF101 | Antimony, Total 1074 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 11, 2022 12:15, sampling point TF101 | Beryllium, Total 1075 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 11, 2022 12:15, sampling point TF101 | Thallium, Total 1085 EPA method 200.8 | Jan 1, 2020 – Dec 31, 2022 |
|
||
| 16.9 ug/l , sample collected Apr 11, 2022 13:03, sampling point SM2 | Total Haloacetic Acids (Haa5) 2456 EPA method 552.2 | Apr 1, 2022 – Jun 30, 2022 |
|
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| 15.7 ug/l , sample collected Apr 11, 2022 12:55, sampling point SM1 | Total Haloacetic Acids (Haa5) 2456 EPA method 552.2 | Apr 1, 2022 – Jun 30, 2022 |
|
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| 10.4 ug/l , sample collected Apr 11, 2022 13:03, sampling point SM2 | TTHM 2950 EPA method 524.2 | Apr 1, 2022 – Jun 30, 2022 |
-
- Collected
- Jul 20, 2022 12:05
- Sampling point
- SM1 Location withheld
- Sample type
- Routine
- Lab sample
- TH-220721-001
- Laboratory
- MSDH Lab
- Monitoring period
- Jul 1, 2022 – Sep 30, 2022
-
TTHM 2950 EPA method 524.2
- Result
- 11.1 ug/l
-
- Collected
- Jun 15, 2022 07:02
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- PB-220616-025
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.606 mg/l
-
Lead 1030 EPA method 200.8
- Result
- 1.6 ug/l
-
- Collected
- Jun 15, 2022 07:04
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- PB-220616-024
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.663 mg/l
-
Lead 1030 EPA method 200.8
- Result
- Not detected below 0.5 ug/l Minimum Reporting Level
-
- Collected
- Jun 15, 2022 07:10
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- PB-220616-023
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.596 mg/l
-
Lead 1030 EPA method 200.8
- Result
- 1.4 ug/l
-
- Collected
- Jun 15, 2022 06:58
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- PB-220616-022
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.0077 mg/l
-
Lead 1030 EPA method 200.8
- Result
- Not detected below 0.5 ug/l Minimum Reporting Level
-
- Collected
- Jun 15, 2022 07:40
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- PB-220616-021
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.852 mg/l
-
Lead 1030 EPA method 200.8
- Result
- 1.8 ug/l
-
- Collected
- May 11, 2022 12:15
- Sampling point
- TF101 Treatment Plant T101
- Sample type
- Routine
- Lab sample
- IN-220512-023
- Laboratory
- MSDH Lab
-
Arsenic 1005 EPA method 200.8
- Result
- 0.0016 mg/l
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Barium 1010 EPA method 200.8
- Result
- 0.0089 mg/l
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Cadmium 1015 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Chromium 1020 EPA method 200.8
- Result
- 0.0006 mg/l
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Fluoride 1025 EPA method QC 10-109-12-2-A
- Result
- 0.353 mg/l
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Mercury 1035 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Nickel 1036 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Not recorded
-
Selenium 1045 EPA method 200.8
- Result
- 0.0054 mg/l
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Antimony, Total 1074 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Beryllium, Total 1075 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
Thallium, Total 1085 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2020 – Dec 31, 2022
-
- Collected
- Apr 11, 2022 13:03
- Sampling point
- SM2 Location withheld
- Sample type
- Routine
- Lab sample
- HA-220412-002
- Laboratory
- MSDH Lab
- Monitoring period
- Apr 1, 2022 – Jun 30, 2022
-
Total Haloacetic Acids (Haa5) 2456 EPA method 552.2
- Result
- 16.9 ug/l
-
- Collected
- Apr 11, 2022 12:55
- Sampling point
- SM1 Location withheld
- Sample type
- Routine
- Lab sample
- HA-220412-001
- Laboratory
- MSDH Lab
- Monitoring period
- Apr 1, 2022 – Jun 30, 2022
-
Total Haloacetic Acids (Haa5) 2456 EPA method 552.2
- Result
- 15.7 ug/l
-
- Collected
- Apr 11, 2022 13:03
- Sampling point
- SM2 Location withheld
- Sample type
- Routine
- Lab sample
- TH-220412-002
- Laboratory
- MSDH Lab
- Monitoring period
- Apr 1, 2022 – Jun 30, 2022
-
TTHM 2950 EPA method 524.2
- Result
- 10.4 ug/l
Routine (10).