| Obviously, discharging "dark and murky" polluted water is bad. But some of the figures from the lab report don't seem that terrible: * Hexavalent chromium at 0.0104 milligrams per liter, just above the lab’s reporting limit of 0.01 mg/L. Hexavalent chromium is classified as a known human carcinogen by the US National Toxicology Program. It is the substance the Erin Brockovich case was built around. * Arsenic at 0.0025 mg/L. That is below the federal drinking water standard of 0.01 mg/L, but present. The hexavalent chromium is also just barely above the California drinking water standard [1] [1] https://www.waterboards.ca.gov/drinking_water/certlic/drinki... |
That is well below the noise floor. Like the similarly toxic selenium, arsenic is an essential micronutrient in animal biology. It is possible to be deficient in arsenic, though rare in practice. Natural background levels are far higher in many locales with no adverse effects.
I often see trace quantities of arsenic trotted out by the popular media for scaremongering purposes. Examples like the above are an immediate red flag.