Skip to main content
Alpha

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

MS0730010 , Lake Arrowhead

19 of the 57 analytes this system has been tested for have been detected at least once, across 284 samples on record.

The other 38 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 284 samples on record, detections range from November 5, 2003 to April 2, 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 Lake Arrowhead, 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
Copper, Free 1022 Inorganic Chemical 82 of 83 results Sep 27, 2004 Aug 28, 2023
Lead 1030 Inorganic Chemical 41 of 83 results Sep 27, 2004 Sep 9, 2020
Barium 1010 Inorganic Chemical 29 of 29 results Nov 5, 2003 Apr 2, 2025
Fluoride 1025 Inorganic Chemical 24 of 29 results Nov 5, 2003 Apr 2, 2025
Nitrate 1040 Inorganic Chemical 19 of 64 results Jun 16, 2004 Apr 17, 2024
Nitrate-Nitrite 1038 Inorganic Chemical 16 of 64 results Apr 2, 2012 Apr 17, 2024
Nickel 1036 Inorganic Chemical 14 of 29 results May 29, 2013 Apr 2, 2025
Chromium 1020 Inorganic Chemical 12 of 29 results Nov 16, 2004 Dec 13, 2016
Gross Alpha, Incl. Radon & U 4002 Radionuclide 10 of 15 results Mar 12, 2012 Oct 12, 2012
Sodium 1052 Inorganic Chemical 6 of 6 results Sep 16, 2019 Mar 28, 2023
Combined Radium (-226 & -228) 4010 Radionuclide 5 of 15 results Mar 12, 2012 Oct 12, 2012
Radium-228 4030 Radionuclide 5 of 15 results Mar 12, 2012 Oct 12, 2012
Nitrite 1041 Inorganic Chemical 4 of 64 results Dec 6, 2004 Apr 17, 2024
Sulfate 1055 Inorganic Chemical 4 of 4 results Nov 5, 2003 Mar 29, 2004
TTHM 2950 Organic Chemical 2 of 7 results Sep 20, 2007 Jul 15, 2010
Selenium 1045 Inorganic Chemical 2 of 29 results Mar 29, 2004 Nov 16, 2004
Total Haloacetic Acids (Haa5) 2456 Organic Chemical 1 of 7 results Jul 15, 2010 Jul 15, 2010
Toluene 2991 Organic Chemical 1 of 28 results Sep 22, 2004 Sep 22, 2004
Cadmium 1015 Inorganic Chemical 1 of 29 results Nov 5, 2003 Nov 5, 2003

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 284 samples, newest first — collected December 6, 2005 to July 27, 2006. The summary above covers all 284.

66 results from the 10 samples listed here: 12 detected, 54 not detected. Across the whole record it is 278 of 1,425. A sample is analysed for many analytes at once, so one sample appears on as many rows as it had results.

Chemical and radiological sample results for Lake Arrowhead, every result from 231 to 240 of 284 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
Jul 27, 2006
Sampling point
DS000 Distribution
Sample type
Routine
Lab sample
060728-150PB
Laboratory
MSDH Lab
0.0409 mg/l , sample collected Jul 27, 2006, sampling point DS000 Copper, Free 1022 EPA method 200.8 Jan 1, 2006 – Dec 31, 2006
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Jul 27, 2006, sampling point DS000 Lead 1030 EPA method 200.8 Jan 1, 2006 – Dec 31, 2006
Collected
Jul 27, 2006
Sampling point
DS000 Distribution
Sample type
Routine
Lab sample
060728-148PB
Laboratory
MSDH Lab
0.0588 mg/l , sample collected Jul 27, 2006, sampling point DS000 Copper, Free 1022 EPA method 200.8 Jan 1, 2006 – Dec 31, 2006
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Jul 27, 2006, sampling point DS000 Lead 1030 EPA method 200.8 Jan 1, 2006 – Dec 31, 2006
Collected
Jul 27, 2006
Sampling point
DS000 Distribution
Sample type
Routine
Lab sample
060728-149PB
Laboratory
MSDH Lab
0.0115 mg/l , sample collected Jul 27, 2006, sampling point DS000 Copper, Free 1022 EPA method 200.8 Jan 1, 2006 – Dec 31, 2006
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Jul 27, 2006, sampling point DS000 Lead 1030 EPA method 200.8 Jan 1, 2006 – Dec 31, 2006
Collected
Apr 20, 2006
Sampling point
TF101 Treatment Plant T101
Sample type
Routine
Lab sample
060420-007IN
Laboratory
MSDH Lab
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 20, 2006, sampling point TF101 Arsenic 1005 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
0.017054 mg/l , sample collected Apr 20, 2006, sampling point TF101 Barium 1010 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0001 mg/l Minimum Reporting Level , sample collected Apr 20, 2006, sampling point TF101 Cadmium 1015 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
0.000748 mg/l , sample collected Apr 20, 2006, sampling point TF101 Chromium 1020 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
0.295508 mg/l , sample collected Apr 20, 2006, sampling point TF101 Fluoride 1025 EPA method 380-75WE Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0002 mg/l Minimum Reporting Level , sample collected Apr 20, 2006, sampling point TF101 Mercury 1035 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 20, 2006, sampling point TF101 Nickel 1036 EPA method 200.8 Not recorded
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 20, 2006, sampling point TF101 Selenium 1045 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 20, 2006, sampling point TF101 Antimony, Total 1074 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0001 mg/l Minimum Reporting Level , sample collected Apr 20, 2006, sampling point TF101 Beryllium, Total 1075 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 20, 2006, sampling point TF101 Thallium, Total 1085 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 20, 2006, sampling point TF101 Uranium-238 4009 Not recorded
Collected
Apr 19, 2006
Sampling point
TF102 Treatment Plant T102
Sample type
Routine
Lab sample
060420-053CN
Laboratory
MSDH Lab
Not detected below 0.005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Cyanide 1024 EPA method QC10204001X Jan 1, 2005 – Dec 31, 2007
Collected
Apr 19, 2006
Sampling point
TF103 Treatment Plant T103
Sample type
Routine
Lab sample
060420-055CN
Laboratory
MSDH Lab
Not detected below 0.005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Cyanide 1024 EPA method QC10204001X Jan 1, 2005 – Dec 31, 2007
Collected
Apr 19, 2006
Sampling point
TF101 Treatment Plant T101
Sample type
Routine
Lab sample
060420-057CN
Laboratory
MSDH Lab
Not detected below 0.005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF101 Cyanide 1024 EPA method QC10204001X Jan 1, 2005 – Dec 31, 2007
Collected
Apr 19, 2006
Sampling point
TF103 Treatment Plant T103
Sample type
Routine
Lab sample
060420-009IN
Laboratory
MSDH Lab
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Arsenic 1005 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
0.017135 mg/l , sample collected Apr 19, 2006, sampling point TF103 Barium 1010 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0001 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Cadmium 1015 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
0.000897 mg/l , sample collected Apr 19, 2006, sampling point TF103 Chromium 1020 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
0.311768 mg/l , sample collected Apr 19, 2006, sampling point TF103 Fluoride 1025 EPA method 380-75WE Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0002 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Mercury 1035 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Nickel 1036 EPA method 200.8 Not recorded
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Selenium 1045 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Antimony, Total 1074 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0001 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Beryllium, Total 1075 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Thallium, Total 1085 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF103 Uranium-238 4009 Not recorded
Collected
Apr 19, 2006
Sampling point
TF102 Treatment Plant T102
Sample type
Routine
Lab sample
060420-008IN
Laboratory
MSDH Lab
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Arsenic 1005 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
0.015238 mg/l , sample collected Apr 19, 2006, sampling point TF102 Barium 1010 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0001 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Cadmium 1015 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
0.000769 mg/l , sample collected Apr 19, 2006, sampling point TF102 Chromium 1020 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
0.319275 mg/l , sample collected Apr 19, 2006, sampling point TF102 Fluoride 1025 EPA method 380-75WE Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0002 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Mercury 1035 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Nickel 1036 EPA method 200.8 Not recorded
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Selenium 1045 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Antimony, Total 1074 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0001 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Beryllium, Total 1075 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Thallium, Total 1085 EPA method 200.8 Jan 1, 2005 – Dec 31, 2007
Not detected below 0.0005 mg/l Minimum Reporting Level , sample collected Apr 19, 2006, sampling point TF102 Uranium-238 4009 Not recorded
Collected
Dec 6, 2005
Sampling point
TF101 Treatment Plant T101
Sample type
Routine
Lab sample
051207-035VO
Laboratory
MSDH Lab
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 1,2,4-Trichlorobenzene 2378 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Cis-1,2-Dichloroethylene 2380 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Xylenes, Total 2955 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Dichloromethane 2964 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 O-Dichlorobenzene 2968 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 P-Dichlorobenzene 2969 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Vinyl Chloride 2976 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 1,1-Dichloroethylene 2977 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Trans-1,2-Dichloroethylene 2979 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 1,2-Dichloroethane 2980 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 1,1,1-Trichloroethane 2981 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Carbon Tetrachloride 2982 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 1,2-Dichloropropane 2983 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Trichloroethylene 2984 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 1,1,2-Trichloroethane 2985 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Tetrachloroethylene 2987 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Chlorobenzene 2989 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Benzene 2990 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Toluene 2991 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Ethylbenzene 2992 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005
Not detected below 0.0005 mg/l Method Detection Limit , sample collected Dec 6, 2005, sampling point TF101 Styrene 2996 EPA method 524.2 Oct 1, 2005 – Dec 31, 2005

Routine (10).