Arsenic levels in California's drinking water will have to be reduced beyond the national 10 parts per billion (ppb) set by the U.S. Environmental Protection Agency (EPA) to an extremely low 4 parts per trillion (ppt)–about 2,500 times lower. The level is set so low that existing technologies cannot measure it. The cost is estimated at more than $80 million to ratepayers.
The federal arsenic rule of 10 ppb is set to take effect in 2006, which was reduced from 50 ppb. The Department of Health Services estimated that it would cost $80 million just to bring the more than 500 wells into compliance with the 10 ppb limit, reported an article in the Mercury News.
The next step for the Department of Health Services means taking the new public health goal and creating a economically and technically feasible standard for the maximum allowable limit.
An article in the Daily Democrat reported that should the new MCL be lowered to 2 ppb more than 2,600 wells would have to be treated at an estimated expense of $750 million in addition to the $34 million to treat surface water. With any of these costs, there also will be additional operational and maintenance costs.
The National Resources Defense Council is suggesting the standard be set at 3 ppb. The EPA stated that anything in the ppt is a "long-term objective" that would not be attainable any time soon.
Long-term exposure to arsenic is proven to result in health effects such as cancer, cardiovascular disease, diabetes and reproductive problems.
In the United States, approximately 3,000 (or 5.5 percent) of the nation's 54,000 community water systems and 1,100 (or 5.5 percent) of the 20,000 non-transient non-community water systems will need to take measures to lower arsenic in their drinking water. Of the affected systems, 97 percent serve fewer than 10,000 people.
The Environmental Protection Agency (EPA) estimates that approximately 13 million people in the U.S. alone routinely drink water containing arsenic at concentrations greater than allowed under recently established government standards. The EPA's arsenic rule requires treatment for all drinking water and industrial wastewater with arsenic levels greater than 10 ppb, by January 2006. This represents a dramatic decrease from the current standard of 50 ppb.