410.848.1014Maximum Contaminant Levels
Maximum Contaminant Levels (MCL) are issued by the US EPA under the Safe Drinking Water Act (SWDA). Here are the MCLs for some of the substances we commonly test for.
Inorganics MCL
| Analyte | MCL (mg/L) |
|---|---|
| Antimony | 0.006 |
| Arsenic | 0.010 |
| Barium | 2 |
| Beryllium | 0.004 |
| Cadmium | 0.005 |
| Chromium | 0.1 |
| Cyanide | 0.2 |
| Mercury | 0.002 |
| Nitrate | 10 |
| Nitrite | 1 |
| Selenium | 0.05 |
| Thallium | 0.002 |
| Lead | 0.015 TT/AL* |
| Copper | 1.3 TT/AL* |
| Secondary Contaminants | SMCL** |
| Aluminum | 0.05 to 0.2 |
| Chloride | 250 |
| Detergents | 0.5 |
| Iron | 0.3 |
| Manganese | 0.05 |
| pH | 6.5-8.5 |
| Silver | 0.1 |
| Sulfate | 250 |
| Total Dissolved Solids | 500 |
*Treatment Technique – An enforceable procedure or level of technical performance which public water systems must follow to ensure control of a contaminant.
Action Level – Level at which action must be taken to reduce contaminant.
** SMCL – Secondary Maximum Contaminant Level (non-enforcable)
Organics MCL
| Analyte | MCL (mg/L) |
|---|---|
| Alachlor | 0.002 |
| Altrazine | 0.003 |
| Benzene | 0.005 |
| Chlordane | 0.002 |
| Ethylbenzene | 0.7 |
| Glyphosate | 0.7 |
| Lindane | 0.0002 |
| Methoxychlor | 0.04 |
| Toluene | 1 |
| Toxaphene | 0.003 |
| Trichloroethene | 0.005 |
| Vinyl Chloride | 0.002 |
Methyl Tertiary Butyl Ether, or MTBE, is an oxygenate – a fuel additive which was added to gasoline to aid in its more complete combustion. Due to its solubility in water, MTBE has been found as a contaminant in many water wells throughout the state. Most of this contamination is due to gasoline spills or leaks.
Although MTBE is not currently regulated, a drinking water advisory has been issued. See the EPA website for more information.
