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.

Every analyte ever detected for Town of Lyon, with how many results found it and when it was first and last detected. Covers the whole record, not only 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 101–110 of 379 samples, newest first — collected May 1, 2018 to September 17, 2018. The summary above covers all 379.

46 results from the 10 samples listed here: 37 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.

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.

Chemical and radiological sample results for Town of Lyon, every result from 101 to 110 of 379 samples shown, newest first. Not detected means the amount was below the level the laboratory can reliably report, which is given beside it.
Result	Analyte	Monitoring period
Collected Sep 17, 2018 01:15 Sampling point SM2 Location withheld Sample type Routine Lab sample 180918-022TH Laboratory MSDH Lab
3.22 ug/l , sample collected Sep 17, 2018 01:15, sampling point SM2	Chloroform 2941 EPA method 524.2	Not recorded
9.2 ug/l , sample collected Sep 17, 2018 01:15, sampling point SM2	Bromoform 2942 EPA method 524.2	Not recorded
4.21 ug/l , sample collected Sep 17, 2018 01:15, sampling point SM2	Bromodichloromethane 2943 EPA method 524.2	Not recorded
9.28 ug/l , sample collected Sep 17, 2018 01:15, sampling point SM2	Dibromochloromethane 2944 EPA method 524.2	Not recorded
25.9 ug/l , sample collected Sep 17, 2018 01:15, sampling point SM2	TTHM 2950	Jul 1, 2018 – Sep 30, 2018
Collected Sep 17, 2018 01:00 Sampling point SM1 Location withheld Sample type Routine Lab sample 180918-021TH Laboratory MSDH Lab
3.22 ug/l , sample collected Sep 17, 2018 01:00, sampling point SM1	Chloroform 2941 EPA method 524.2	Not recorded
9.61 ug/l , sample collected Sep 17, 2018 01:00, sampling point SM1	Bromoform 2942 EPA method 524.2	Not recorded
4.24 ug/l , sample collected Sep 17, 2018 01:00, sampling point SM1	Bromodichloromethane 2943 EPA method 524.2	Not recorded
9.56 ug/l , sample collected Sep 17, 2018 01:00, sampling point SM1	Dibromochloromethane 2944 EPA method 524.2	Not recorded
26.63 ug/l , sample collected Sep 17, 2018 01:00, sampling point SM1	TTHM 2950	Jul 1, 2018 – Sep 30, 2018
Collected Aug 14, 2018 01:00 Sampling point SM2 Location withheld Sample type Routine Lab sample 180815-016HA Laboratory MSDH Lab
0.01 mg/l , sample collected Aug 14, 2018 01:00, sampling point SM2	Monochloroacetic Acid 2450 EPA method 552.2	Not recorded
0.002 mg/l , sample collected Aug 14, 2018 01:00, sampling point SM2	Dichloroacetic Acid 2451 EPA method 552.2	Not recorded
Not detected below 0.001 mg/l Minimum Reporting Level , sample collected Aug 14, 2018 01:00, sampling point SM2	Trichloroacetic Acid 2452 EPA method 552.2	Not recorded
0.001 mg/l , sample collected Aug 14, 2018 01:00, sampling point SM2	Monobromoacetic Acid 2453 EPA method 552.2	Not recorded
0.007 mg/l , sample collected Aug 14, 2018 01:00, sampling point SM2	Dibromoacetic Acid 2454 EPA method 552.2	Not recorded
0.02 mg/l , sample collected Aug 14, 2018 01:00, sampling point SM2	Total Haloacetic Acids (Haa5) 2456	Jul 1, 2018 – Sep 30, 2018
Collected Aug 14, 2018 01:15 Sampling point SM1 Location withheld Sample type Routine Lab sample 180815-015HA Laboratory MSDH Lab
Not detected below 0.002 mg/l Minimum Reporting Level , sample collected Aug 14, 2018 01:15, sampling point SM1	Monochloroacetic Acid 2450 EPA method 552.2	Not recorded
0.001 mg/l , sample collected Aug 14, 2018 01:15, sampling point SM1	Dichloroacetic Acid 2451 EPA method 552.2	Not recorded
0.001 mg/l , sample collected Aug 14, 2018 01:15, sampling point SM1	Trichloroacetic Acid 2452 EPA method 552.2	Not recorded
Not detected below 0.001 mg/l Minimum Reporting Level , sample collected Aug 14, 2018 01:15, sampling point SM1	Monobromoacetic Acid 2453 EPA method 552.2	Not recorded
0.009 mg/l , sample collected Aug 14, 2018 01:15, sampling point SM1	Dibromoacetic Acid 2454 EPA method 552.2	Not recorded
0.011 mg/l , sample collected Aug 14, 2018 01:15, sampling point SM1	Total Haloacetic Acids (Haa5) 2456	Jul 1, 2018 – Sep 30, 2018
Collected Jul 17, 2018 13:20 Sampling point TF101 Treatment Plant T101 Sample type Routine Lab sample 180718-011RU Laboratory MSDH Lab
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Jul 17, 2018 13:20, sampling point TF101	Combined Uranium 4006 EPA method 200.8	Jan 1, 2013 – Dec 31, 2021
Collected May 15, 2018 12:45 Sampling point SM2 Location withheld Sample type Routine Lab sample 180516-002TH Laboratory MSDH Lab
2.7 ug/l , sample collected May 15, 2018 12:45, sampling point SM2	Chloroform 2941 EPA method 524.2	Not recorded
25.4 ug/l , sample collected May 15, 2018 12:45, sampling point SM2	Bromoform 2942 EPA method 524.2	Not recorded
4.98 ug/l , sample collected May 15, 2018 12:45, sampling point SM2	Bromodichloromethane 2943 EPA method 524.2	Not recorded
16.4 ug/l , sample collected May 15, 2018 12:45, sampling point SM2	Dibromochloromethane 2944 EPA method 524.2	Not recorded
49.5 ug/l , sample collected May 15, 2018 12:45, sampling point SM2	TTHM 2950	Apr 1, 2018 – Jun 30, 2018
Collected May 15, 2018 12:30 Sampling point SM1 Location withheld Sample type Routine Lab sample 180516-001TH Laboratory MSDH Lab
2.79 ug/l , sample collected May 15, 2018 12:30, sampling point SM1	Chloroform 2941 EPA method 524.2	Not recorded
25.1 ug/l , sample collected May 15, 2018 12:30, sampling point SM1	Bromoform 2942 EPA method 524.2	Not recorded
5.24 ug/l , sample collected May 15, 2018 12:30, sampling point SM1	Bromodichloromethane 2943 EPA method 524.2	Not recorded
16.6 ug/l , sample collected May 15, 2018 12:30, sampling point SM1	Dibromochloromethane 2944 EPA method 524.2	Not recorded
49.7 ug/l , sample collected May 15, 2018 12:30, sampling point SM1	TTHM 2950	Apr 1, 2018 – Jun 30, 2018
Collected May 15, 2018 12:45 Sampling point SM2 Location withheld Sample type Routine Lab sample 180516-002HA Laboratory MSDH Lab
Not detected below 0.002 mg/l Minimum Reporting Level , sample collected May 15, 2018 12:45, sampling point SM2	Monochloroacetic Acid 2450 EPA method 552.2	Not recorded
0.001 mg/l , sample collected May 15, 2018 12:45, sampling point SM2	Dichloroacetic Acid 2451 EPA method 552.2	Not recorded
0.001 mg/l , sample collected May 15, 2018 12:45, sampling point SM2	Trichloroacetic Acid 2452 EPA method 552.2	Not recorded
Not detected below 0.001 mg/l Minimum Reporting Level , sample collected May 15, 2018 12:45, sampling point SM2	Monobromoacetic Acid 2453 EPA method 552.2	Not recorded
0.009 mg/l , sample collected May 15, 2018 12:45, sampling point SM2	Dibromoacetic Acid 2454 EPA method 552.2	Not recorded
0.011 mg/l , sample collected May 15, 2018 12:45, sampling point SM2	Total Haloacetic Acids (Haa5) 2456	Apr 1, 2018 – Jun 30, 2018
Collected May 15, 2018 12:30 Sampling point SM1 Location withheld Sample type Routine Lab sample 180516-001HA Laboratory MSDH Lab
Not detected below 0.002 mg/l Minimum Reporting Level , sample collected May 15, 2018 12:30, sampling point SM1	Monochloroacetic Acid 2450 EPA method 552.2	Not recorded
0.001 mg/l , sample collected May 15, 2018 12:30, sampling point SM1	Dichloroacetic Acid 2451 EPA method 552.2	Not recorded
0.001 mg/l , sample collected May 15, 2018 12:30, sampling point SM1	Trichloroacetic Acid 2452 EPA method 552.2	Not recorded
Not detected below 0.001 mg/l Minimum Reporting Level , sample collected May 15, 2018 12:30, sampling point SM1	Monobromoacetic Acid 2453 EPA method 552.2	Not recorded
0.01 mg/l , sample collected May 15, 2018 12:30, sampling point SM1	Dibromoacetic Acid 2454 EPA method 552.2	Not recorded
0.01 mg/l , sample collected May 15, 2018 12:30, sampling point SM1	Total Haloacetic Acids (Haa5) 2456	Apr 1, 2018 – Jun 30, 2018
Collected May 1, 2018 01:00 Sampling point TF101 Treatment Plant T101 Sample type Routine Lab sample 180502-021CN Laboratory MSDH Lab
Not detected below 0.015 mg/l Minimum Reporting Level , sample collected May 1, 2018 01:00, sampling point TF101	Cyanide 1024 EPA method QC10204001X	Jan 1, 2017 – Dec 31, 2019

Collected
Sep 17, 2018 01:15

Sampling point
SM2 Location withheld

Sample type
Routine

Lab sample
180918-022TH

Laboratory
MSDH Lab
- Chloroform 2941 EPA method 524.2
  
  Result
  3.22 ug/l
  
  Monitoring period
  Not recorded
- Bromoform 2942 EPA method 524.2
  
  Result
  9.2 ug/l
  
  Monitoring period
  Not recorded
- Bromodichloromethane 2943 EPA method 524.2
  
  Result
  4.21 ug/l
  
  Monitoring period
  Not recorded
- Dibromochloromethane 2944 EPA method 524.2
  
  Result
  9.28 ug/l
  
  Monitoring period
  Not recorded
- TTHM 2950
  
  Result
  25.9 ug/l
  
  Monitoring period
  Jul 1, 2018 – Sep 30, 2018
Collected
Sep 17, 2018 01:00

Sampling point
SM1 Location withheld

Sample type
Routine

Lab sample
180918-021TH

Laboratory
MSDH Lab
- Chloroform 2941 EPA method 524.2
  
  Result
  3.22 ug/l
  
  Monitoring period
  Not recorded
- Bromoform 2942 EPA method 524.2
  
  Result
  9.61 ug/l
  
  Monitoring period
  Not recorded
- Bromodichloromethane 2943 EPA method 524.2
  
  Result
  4.24 ug/l
  
  Monitoring period
  Not recorded
- Dibromochloromethane 2944 EPA method 524.2
  
  Result
  9.56 ug/l
  
  Monitoring period
  Not recorded
- TTHM 2950
  
  Result
  26.63 ug/l
  
  Monitoring period
  Jul 1, 2018 – Sep 30, 2018
Collected
Aug 14, 2018 01:00

Sampling point
SM2 Location withheld

Sample type
Routine

Lab sample
180815-016HA

Laboratory
MSDH Lab
- Monochloroacetic Acid 2450 EPA method 552.2
  
  Result
  0.01 mg/l
  
  Monitoring period
  Not recorded
- Dichloroacetic Acid 2451 EPA method 552.2
  
  Result
  0.002 mg/l
  
  Monitoring period
  Not recorded
- Trichloroacetic Acid 2452 EPA method 552.2
  
  Result
  Not detected below 0.001 mg/l Minimum Reporting Level
  
  Monitoring period
  Not recorded
- Monobromoacetic Acid 2453 EPA method 552.2
  
  Result
  0.001 mg/l
  
  Monitoring period
  Not recorded
- Dibromoacetic Acid 2454 EPA method 552.2
  
  Result
  0.007 mg/l
  
  Monitoring period
  Not recorded
- Total Haloacetic Acids (Haa5) 2456
  
  Result
  0.02 mg/l
  
  Monitoring period
  Jul 1, 2018 – Sep 30, 2018
Collected
Aug 14, 2018 01:15

Sampling point
SM1 Location withheld

Sample type
Routine

Lab sample
180815-015HA

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
  0.001 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
  0.009 mg/l
  
  Monitoring period
  Not recorded
- Total Haloacetic Acids (Haa5) 2456
  
  Result
  0.011 mg/l
  
  Monitoring period
  Jul 1, 2018 – Sep 30, 2018
Collected
Jul 17, 2018 13:20

Sampling point
TF101 Treatment Plant T101

Sample type
Routine

Lab sample
180718-011RU

Laboratory
MSDH Lab

Monitoring period
Jan 1, 2013 – Dec 31, 2021
- Combined Uranium 4006 EPA method 200.8
  
  Result
  Not detected below 0.0005 mg/l Minimum Reporting Level
Collected
May 15, 2018 12:45

Sampling point
SM2 Location withheld

Sample type
Routine

Lab sample
180516-002TH

Laboratory
MSDH Lab
- Chloroform 2941 EPA method 524.2
  
  Result
  2.7 ug/l
  
  Monitoring period
  Not recorded
- Bromoform 2942 EPA method 524.2
  
  Result
  25.4 ug/l
  
  Monitoring period
  Not recorded
- Bromodichloromethane 2943 EPA method 524.2
  
  Result
  4.98 ug/l
  
  Monitoring period
  Not recorded
- Dibromochloromethane 2944 EPA method 524.2
  
  Result
  16.4 ug/l
  
  Monitoring period
  Not recorded
- TTHM 2950
  
  Result
  49.5 ug/l
  
  Monitoring period
  Apr 1, 2018 – Jun 30, 2018
Collected
May 15, 2018 12:30

Sampling point
SM1 Location withheld

Sample type
Routine

Lab sample
180516-001TH

Laboratory
MSDH Lab
- Chloroform 2941 EPA method 524.2
  
  Result
  2.79 ug/l
  
  Monitoring period
  Not recorded
- Bromoform 2942 EPA method 524.2
  
  Result
  25.1 ug/l
  
  Monitoring period
  Not recorded
- Bromodichloromethane 2943 EPA method 524.2
  
  Result
  5.24 ug/l
  
  Monitoring period
  Not recorded
- Dibromochloromethane 2944 EPA method 524.2
  
  Result
  16.6 ug/l
  
  Monitoring period
  Not recorded
- TTHM 2950
  
  Result
  49.7 ug/l
  
  Monitoring period
  Apr 1, 2018 – Jun 30, 2018
Collected
May 15, 2018 12:45

Sampling point
SM2 Location withheld

Sample type
Routine

Lab sample
180516-002HA

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
  0.001 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
  0.009 mg/l
  
  Monitoring period
  Not recorded
- Total Haloacetic Acids (Haa5) 2456
  
  Result
  0.011 mg/l
  
  Monitoring period
  Apr 1, 2018 – Jun 30, 2018
Collected
May 15, 2018 12:30

Sampling point
SM1 Location withheld

Sample type
Routine

Lab sample
180516-001HA

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
  0.001 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
  0.01 mg/l
  
  Monitoring period
  Not recorded
- Total Haloacetic Acids (Haa5) 2456
  
  Result
  0.01 mg/l
  
  Monitoring period
  Apr 1, 2018 – Jun 30, 2018
Collected
May 1, 2018 01:00

Sampling point
TF101 Treatment Plant T101

Sample type
Routine

Lab sample
180502-021CN

Laboratory
MSDH Lab

Monitoring period
Jan 1, 2017 – Dec 31, 2019
- Cyanide 1024 EPA method QC10204001X
  
  Result
  Not detected below 0.015 mg/l Minimum Reporting Level

Routine (10).