Municipalities that would have to correct their water systems have argued that the cost to them would far outweigh the benefits to the public in cleansing arsenic, which occurs naturally, out of drinking water.
Arsenic is a common byproduct of mining operations, so stricter standards for its in drinking water would translate into stricter standards for many mining sites.
The report completed by the academy examined only the public health consequences of arsenic and did not conduct a cost-benefit analysis for water suppliers.