St. Helens Chronicle. The St. Helens woman has been missing for two weeks. Her boyfriend, currently in the Lane County jail for other offenses, is now considered a person of interest. Police are currently searching for St. Helens woman, Cheryl Hart, who has been missing for nearly two weeks.
First, there are typically two varieties, or species, of arsenic in water: arsenic 3 and arsenic 5.. This is significant because arsenic 3 is very difficult to remove from water and must be changed or oxidized to arsenic 5 before it can be removed.
What is the public drinking water standard? Arsenic is regulated in public drinking water systems by the Environmental Protection Agency (EPA) and a maximum allowable limit-known as a maximum contaminant level (MCL)-has been established for it to protect against long-term exposure. For many years, the MCL for total arsenic was 50 ppb.