| Contaminant | In Water As | Maximum Contaminant Level |
| Arsenic (As) | When pH = 6-10 As(III), arsenite as H3AsO3 and H2AsO31 As(V), arsenate as H2AsO41- and HAsO42 |
US EPA: MCL* = 0.010 mg/L (or ppm) MCLG** = zero WHO† Guideline = 0.010 mg/L |
*Maximum Contaminant Level (MCL) – The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and considering cost. MCLs are enforceable standards.
**Maximum Contaminant Level Goal (MCLG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
†WHO – World Health Organization
| Sources of Contaminant | Leaching from natural deposits Wood preservatives, pesticides, industrial deposits Petroleum production Semiconductor manufacture Coal power plants |
| Potential Health Effects | Serious skin problems, endocrine disruptor Causes Cancer – skin, bladder, lung, kidney, liver, prostate Harms cardiovascular & nervous systems |
| Treatment Methods Point-of-Entry Point-of-Use |
Iron oxide/hydroxides Activated alumina Iron-based specialty media impregnated or coated with iron oxide/hydroxides Distillation Titanium oxy/hydroxide Anion Exchange (strong base anion exchange resins) Manganese greensand Reverse osmosis (RO) |
In the United States, the EPA, under the authority of the Safe Drinking Water Act (SDWA), has set the Maximum Contaminant Level Goal (MCLG) for arsenic at zero. This is the health-based goal at which no known or anticipated adverse effects on human health occur, with an adequate margin of safety. The US EPA has set the enforceable Maximum Contaminant Level (MCL) at 0.010 mg/L (10 ppb). In Canada, the Maximum Acceptable Concentration (MAC) for arsenic in drinking water is also set at 0.010 mg/L.
This information is sourced from the Water Quality Association (WQA), of which WCC is a proud member. Complete reports are available via the links below. This material is shared with the objective of offering comprehensive, professional insights into relevant water quality standards and guidelines.
