Arsenic Information
What is arsenic?
Arsenic is a semi-metal element in the periodic table. It is odorless and tasteless. The chemical name of arsenic is As.
How does arsenic get into my drinking water?
Arsenic can migrate into our groundwater sources from erosion of naturally occurring rocks, soils, and natural deposits. It can also come from run-off from orchards, glass and electronics production wastes.
What are arsenic's health effects?
Human exposure to arsenic can cause both short and long term health effects. Short or acute effects can occur within hours or days of exposure. Long or chronic effects occur over many years. Long term exposure to arsenic has been linked to cancer of the bladder, lungs, skin, kidneys, nasal passages, liver and prostate. Short term exposure to high doses of arsenic can cause other adverse health effects, but such effects are unlikely to occur from U.S. public water supplies that are in compliance with the arsenic standard.
What is the Arsenic Drinking Water Standard?
The USEPA has established an MCL (Maximum Contaminant Level) of 10 μg/L or ppb. Values below this level comply with the arsenic standard and water with less than 10 μg/L is considered safe to drink according to the USEPA.
How often are Tucson Water wells tested for arsenic to comply with the Arsenic Rule?
The Arsenic Rule requires public water systems, like Tucson Water, to test their drinking water wells once every three years to ensure compliance with the arsenic MCL.
A system with a sampling point result above the MCL must collect quarterly samples at that sampling point, until the system is reliably and consistently below the MCL.
As a reminder for all of our Tucson Water customers, the water we deliver meets the arsenic MCL and is safe to drink.
How will I know if there is arsenic in my water?
Every summer, Tucson Water sends you an Annual Water Quality Report (also known as the Consumer Confidence Report, or CCR), listing any levels of arsenic detected. The Arizona Department of Environmental Quality also requires Tucson Water to give you public notice within 30 days should our water supply violate the arsenic standard or MCL. You will be given information about what is being done to correct the situation.
What are the most recent arsenic results and what do they mean?
The Arsenic Rule requires samples to be taken from the Entry-Points-to-the-Distribution System (EPDSs). The results of Tucson Water's Compliance Arsenic Monitoring Program conducted in 2007 and 2008 are in the table below.
| Point of Entry or Entry-Point-to-the-Distribution System 1 | Well | Arsenic 2 (ppb) |
|---|---|---|
| POE 001 | A-005B | < 2 |
| POE 002 | A-008B | < 2 |
| POE 003 | A-009B | < 2 |
| POE 005 | A-027B | < 2 |
| POE 006 | A-031A | < 2 |
| POE 009 | A-036A | < 2 |
| POE 010 | A-037A | < 2 |
| POE 012 | A-053A | < 2 |
| POE 013 | A-055A | < 2 |
| POE 016 | B-010B | < 2 |
| POE 017 | B-013B | 6.4 |
| POE 018 | B-019A | 4.5 |
| POE 019 | B-026B | < 2 |
| POE 020 | B-039B | 5 |
| POE 021 | B-042B | 3 |
| POE 022 | B-043B | < 2 |
| POE 024 | B-045B | < 2 |
| POE 027 | B-048B | < 2 |
| POE 028 | B-050A | < 2 |
| POE 029 | B-051B | < 2 |
| POE 030 | B-053B | < 2 |
| POE 031 | B-054B | < 2 |
| POE 033 3 | B-056A | < 2 |
| POE 034 | B-057B | < 2 |
| POE 035 | B-059A | < 2 |
| POE 036 | B-075A | < 2 |
| POE 041 | C-007A | 5.3 |
| POE 043 | C-012B | < 2 |
| POE 045 | C-015A | 4.8 |
| POE 046 | C-020B | < 2 |
| POE 048 | C-025B | < 2 |
| POE 050 | C-030B | < 2 |
| POE 051 | C-032B | < 2 |
| POE 052 | C-033A | < 2 |
| POE 053 | C-036B | 5.5 |
| POE 054 | C-046B | < 2 |
| POE 055 | C-048B | < 2 |
| POE 057 | C-050B | < 2 |
| POE 058 | C-051B | < 2 |
| POE 059 | C-056B | < 2 |
| POE 060 | C-058B | < 2 |
| POE 061 | C-069A | 3.3 |
| POE 062 | C-075B | < 2 |
| POE 063 | C-076A | < 2 |
| POE 064 | C-082A | < 2 |
| POE 065 | C-083B | < 2 |
| POE 066 | C-085A | < 2 |
| POE 068 | C-112A | 2.3 |
| POE 069 | C-114A | < 2 |
| POE 070 | C-115A | < 2 |
| POE 071 | C-116A | 4.7 |
| POE 072 | C-117A | 3 |
| POE 074 | C-119A | < 2 |
| POE 075 | C-120A | 2.6 |
| POE 076 | D-001A | < 2 |
| POE 078 | D-016B | < 2 |
| POE 080 | D-018A | < 2 |
| POE 081 | D-023A | < 2 |
| POE 082 | D-030A | < 2 |
| POE 084 | D-034B | 3.7 |
| POE 085 | D-035A | < 2 |
| POE 086 | D-036A | < 2 |
| POE 087 | D-037B | < 2 |
| POE 088 | D-038A | < 2 |
| POE 089 | D-046B | < 2 |
| POE 090 | D-047A | < 2 |
| POE 091 | D-048A | < 2 |
| POE 092 | D-049A | < 2 |
| POE 093 | D-051A | < 2 |
| POE 094 | D-065A | < 2 |
| POE 096 | E-004A | < 2 |
| POE 097 | E-007A | < 2 |
| POE 098 | E-008A | < 2 |
| POE 099 | E-014A | < 2 |
| POE 100 | E-015A | < 2 |
| POE 101 | E-016A | < 2 |
| POE 102 | E-018B | < 2 |
| POE 103 | E-023B | 9.1 |
| POE 105 | Z-002A | < 2 |
| POE 106 | Z-005A | < 2 |
| POE 109 | Z-013A | < 2 |
| POE 110 | Z-014B | < 2 |
| POE 111 | Z-015A | < 2 |
| POE 112 | Z-017A | < 2 |
| POE 113 | AV-001A | 5.1 |
| POE 114 | AV-002A | 5.8 |
| POE 115 | AV-003A | 6.5 |
| POE 117 | AV-006B | 6.4 |
| POE 118 | AV-007A | 4.3 |
| POE 119 | AV-008A | 6.1 |
| POE 120 | AV-009A | 5.4 |
| POE 123 | SS-024A | 4.9 |
| POE 124 | 167R | 7.4 |
| POE 125 | 310 | 6.3 |
| POE 126 | SP-830 | 4.6 |
| POE 128 | C-123B | 2.9 |
| POE 129 | C-055B | < 2 |
| POE 130 | G-002A | 3.3 |
| POE 132 | C-122A | 2 |
| POE 133 | G-001A | 3.8 |
| POE 134 | G-003A | 5 |
| POE 135 | Z-018A | < 2 |
| POE 138 | C-109A | < 2 |
| POE 140 | AV-027A | 5.7 |
| POE 142 | G-004A | 3.8 |
| POE 143 | C-008B | 5 |
| POE 144 | AV-011A | 8 |
| POE 145 | C-124A | < 2 |
| POE 147 | B-110A | 6.4 |
| POE 148 | E-002A | 2.8 |
| POE 149 | G-005A | 4.6 |
| POE 150 | A-057B | 2.1 |
| POE 151 | C-125A | < 2 |
| POE 152 | B-111A | 2.1 |
| POE 154 | F-008A | < 2 |
| POE 155 | E-026A | < 2 |
| POE 156 | G-008A | 3.6 |
| POE 157 | C-016B | 2.2 |
| POE 159 | EP1 | 6.4 |
| POE 159 | EP1 | 5.4 |
| POE 159 | EP1 | 5.6 |
| POE 159 | EP1 | 5 |
| POE 159 | EP1 | 4.9 |
| POE-159 | EP1 | 6.2 |
| POE 160 | Y-004A | < 2 |
| POE 161 | E-029A | 3 |
| POE 163 | A-060A | < 2 |
| POE 205 | E-024A | 3.1 |
| POE 206 | E-025A | 3.8 |
| POE 210 | F-001A | < 2 |
| POE 211 | F-003A | < 2 |
| POE 215 | F-002A | 2.7 |
| POE 216 | E-030A | 3.8 |
| POE 220 | H-001A | 3.5 |
| POE 221 | H-002A | 3.4 |
| POE 222 | H-003A | < 2 |
| POE 225 | I-001A | < 2 |
| POE 226 | I-002B | < 2 |
| POE 230 | W-001B | 5.7 |
| POE 236 | W-004A | 4 |
| POE 237 | W-005A | 3.6 |
| POE 240 | Y-001A | < 2 |
| POE 245 | F-006A | 2.8 |
| POE 250 | G-006A | < 2 |
| POE 251 | G-009A | < 2 |
| POE 255 | PF-001A | 3.8 |
| POE 270 | G-010A | 5 |
1 Point where water is discharged into the distribution system from a well, storage tank, or water treatment plant.
2 Collected in 2007
3 Collected in 2008
The data shows that arsenic was not found in 60% of the wells tested. The arsenic values detected were between 2 ppb and 9.1 ppb and the average arsenic level measured from the wells was 1.8 ppb.
The results were submitted to the Arizona Department of Environmental Quality (ADEQ) where the data is audited by ADEQ to ensure compliance with the arsenic MCL and other Rule requirements. All of the results show compliance with the USEPA's arsenic MCL of 10 ppb. The water is safe to drink.
For more information, please contact the Water Quality Division of Tucson Water at 791-2544.
Additional Resources:
http://www.epa.gov/safewater/arsenic/index.html
