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 231–240 of 379 samples, newest first — collected May 4, 2011 to August 10, 2011. The summary above covers all 379.
35 results from the 10 samples listed here: 26 detected, 9 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.
| Result | Analyte | Monitoring period |
|---|---|---|
|
||
| Not detected below 15 ug/l Minimum Reporting Level , sample collected Aug 10, 2011 01:30, sampling point TF101 | Cyanide 1024 EPA method QC10204001X | Jan 1, 2011 – Dec 31, 2013 |
|
||
| 0.3642 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
| 0.0011 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
|
||
| 0.2052 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
| 0.0005 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
|
||
| 0.3773 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
| 0.0068 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
|
||
| 0.7647 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
| 0.0013 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
|
||
| 0.4956 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
| 0.0043 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
|
||
| 0.4062 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Copper, Free 1022 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
| 0.0075 mg/l , sample collected Jun 22, 2011, sampling point DS000 | Lead 1030 EPA method 200.8 | Jan 1, 2009 – Dec 31, 2011 |
|
||
| 3.6 ug/l , sample collected May 12, 2011, sampling point MRT000 | Chloroform 2941 EPA method 524.2 | Not recorded |
| 44 ug/l , sample collected May 12, 2011, sampling point MRT000 | Bromoform 2942 EPA method 524.2 | Not recorded |
| 10.1 ug/l , sample collected May 12, 2011, sampling point MRT000 | Bromodichloromethane 2943 EPA method 524.2 | Not recorded |
| 33.1 ug/l , sample collected May 12, 2011, sampling point MRT000 | Dibromochloromethane 2944 EPA method 524.2 | Not recorded |
| 91 ug/l , sample collected May 12, 2011, sampling point MRT000 | TTHM 2950 EPA method 524.2 | Apr 1, 2011 – Jun 30, 2011 |
|
||
| Not detected below 0.002 mg/l Minimum Reporting Level , sample collected May 12, 2011, sampling point MRT000 | Monochloroacetic Acid 2450 EPA method 552.2 | Not recorded |
| 0.001 mg/l , sample collected May 12, 2011, sampling point MRT000 | Dichloroacetic Acid 2451 EPA method 552.2 | Not recorded |
| 0.002 mg/l , sample collected May 12, 2011, sampling point MRT000 | Trichloroacetic Acid 2452 EPA method 552.2 | Not recorded |
| Not detected below 0.001 mg/l Minimum Reporting Level , sample collected May 12, 2011, sampling point MRT000 | Monobromoacetic Acid 2453 EPA method 552.2 | Not recorded |
| 0.014 mg/l , sample collected May 12, 2011, sampling point MRT000 | Dibromoacetic Acid 2454 EPA method 552.2 | Not recorded |
| 0.017 mg/l , sample collected May 12, 2011, sampling point MRT000 | Total Haloacetic Acids (Haa5) 2456 | Apr 1, 2011 – Jun 30, 2011 |
|
||
| 0.0027 mg/l , sample collected May 4, 2011, sampling point TF101 | Arsenic 1005 EPA method 200.8 | Jan 1, 2011 – Dec 31, 2013 |
| 0.009 mg/l , sample collected May 4, 2011, sampling point TF101 | Barium 1010 EPA method 200.8 | Jan 1, 2011 – Dec 31, 2013 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 4, 2011, sampling point TF101 | Cadmium 1015 EPA method 200.8 | Jan 1, 2011 – Dec 31, 2013 |
| 0.0012 mg/l , sample collected May 4, 2011, sampling point TF101 | Chromium 1020 EPA method 200.8 | Jan 1, 2011 – Dec 31, 2013 |
| 0.37 mg/l , sample collected May 4, 2011, sampling point TF101 | Fluoride 1025 EPA method 380-75WE | Jan 1, 2011 – Dec 31, 2013 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 4, 2011, sampling point TF101 | Mercury 1035 EPA method 200.8 | Jan 1, 2011 – Dec 31, 2013 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 4, 2011, sampling point TF101 | Nickel 1036 EPA method 200.8 | Not recorded |
| 0.0098 mg/l , sample collected May 4, 2011, sampling point TF101 | Selenium 1045 EPA method 200.8 | Jan 1, 2011 – Dec 31, 2013 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 4, 2011, sampling point TF101 | Antimony, Total 1074 EPA method 200.8 | Jan 1, 2011 – Dec 31, 2013 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 4, 2011, sampling point TF101 | Beryllium, Total 1075 EPA method 200.8 | Jan 1, 2011 – Dec 31, 2013 |
| Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected May 4, 2011, sampling point TF101 | Thallium, Total 1085 EPA method 200.8 | Jan 1, 2011 – Dec 31, 2013 |
-
- Collected
- Aug 10, 2011 01:30
- Sampling point
- TF101 Treatment Plant T101
- Sample type
- Routine
- Lab sample
- 110811-019CN
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
Cyanide 1024 EPA method QC10204001X
- Result
- Not detected below 15 ug/l Minimum Reporting Level
-
- Collected
- Jun 22, 2011
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- 110623-100PB
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2009 – Dec 31, 2011
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.3642 mg/l
-
Lead 1030 EPA method 200.8
- Result
- 0.0011 mg/l
-
- Collected
- Jun 22, 2011
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- 110623-099PB
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2009 – Dec 31, 2011
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.2052 mg/l
-
Lead 1030 EPA method 200.8
- Result
- 0.0005 mg/l
-
- Collected
- Jun 22, 2011
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- 110623-094PB
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2009 – Dec 31, 2011
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.3773 mg/l
-
Lead 1030 EPA method 200.8
- Result
- 0.0068 mg/l
-
- Collected
- Jun 22, 2011
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- 110623-093PB
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2009 – Dec 31, 2011
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.7647 mg/l
-
Lead 1030 EPA method 200.8
- Result
- 0.0013 mg/l
-
- Collected
- Jun 22, 2011
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- 110623-092PB
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2009 – Dec 31, 2011
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.4956 mg/l
-
Lead 1030 EPA method 200.8
- Result
- 0.0043 mg/l
-
- Collected
- Jun 22, 2011
- Sampling point
- DS000 Distribution
- Sample type
- Routine
- Lab sample
- 110623-091PB
- Laboratory
- MSDH Lab
- Monitoring period
- Jan 1, 2009 – Dec 31, 2011
-
Copper, Free 1022 EPA method 200.8
- Result
- 0.4062 mg/l
-
Lead 1030 EPA method 200.8
- Result
- 0.0075 mg/l
-
- Collected
- May 12, 2011
- Sampling point
- MRT000 Max. Res. Time
- Sample type
- Routine
- Lab sample
- 110513-006TH
- Laboratory
- MSDH Lab
-
Chloroform 2941 EPA method 524.2
- Result
- 3.6 ug/l
- Monitoring period
- Not recorded
-
Bromoform 2942 EPA method 524.2
- Result
- 44 ug/l
- Monitoring period
- Not recorded
-
Bromodichloromethane 2943 EPA method 524.2
- Result
- 10.1 ug/l
- Monitoring period
- Not recorded
-
Dibromochloromethane 2944 EPA method 524.2
- Result
- 33.1 ug/l
- Monitoring period
- Not recorded
-
TTHM 2950 EPA method 524.2
- Result
- 91 ug/l
- Monitoring period
- Apr 1, 2011 – Jun 30, 2011
-
- Collected
- May 12, 2011
- Sampling point
- MRT000 Max. Res. Time
- Sample type
- Routine
- Lab sample
- 110513-006HA
- Laboratory
- MSDH Lab
-
Monochloroacetic Acid 2450 EPA method 552.2
- Result
- Not detected below 0.002 mg/l Minimum Reporting Level
- Monitoring period
- Not recorded
-
Dichloroacetic Acid 2451 EPA method 552.2
- Result
- 0.001 mg/l
- Monitoring period
- Not recorded
-
Trichloroacetic Acid 2452 EPA method 552.2
- Result
- 0.002 mg/l
- Monitoring period
- Not recorded
-
Monobromoacetic Acid 2453 EPA method 552.2
- Result
- Not detected below 0.001 mg/l Minimum Reporting Level
- Monitoring period
- Not recorded
-
Dibromoacetic Acid 2454 EPA method 552.2
- Result
- 0.014 mg/l
- Monitoring period
- Not recorded
-
Total Haloacetic Acids (Haa5) 2456
- Result
- 0.017 mg/l
- Monitoring period
- Apr 1, 2011 – Jun 30, 2011
-
- Collected
- May 4, 2011
- Sampling point
- TF101 Treatment Plant T101
- Sample type
- Routine
- Lab sample
- 110505-025IN
- Laboratory
- MSDH Lab
-
Arsenic 1005 EPA method 200.8
- Result
- 0.0027 mg/l
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
Barium 1010 EPA method 200.8
- Result
- 0.009 mg/l
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
Cadmium 1015 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
Chromium 1020 EPA method 200.8
- Result
- 0.0012 mg/l
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
Fluoride 1025 EPA method 380-75WE
- Result
- 0.37 mg/l
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
Mercury 1035 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
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
- 0.0098 mg/l
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
Antimony, Total 1074 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
Beryllium, Total 1075 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
-
Thallium, Total 1085 EPA method 200.8
- Result
- Not detected below 0.0005 mg/l Minimum Reporting Level
- Monitoring period
- Jan 1, 2011 – Dec 31, 2013
Routine (10).