Date

Action

1942

The drinking water standard was set at 50 parts per billion (ppb) by the U.S Public Health Service.

1975

This standard was adopted by the U.S Environmental Protection Agency (EPA)  as a result of the passage of the Safe Drinking Water Act. 

1989

COntroversy around health effects studies caused postponement of final rule until November, 1992

November 1992

The EPA, citing the need to further to evaluate health effects, postponed the final rule until September 1994

September 1994

Due to a delay in the EPA studies, the final rule was postponed until November 1995.

November 1995

Due to Congressional concerns, including cost of implementing a solution, the final rule was postponed until January 2000,

June 2000

New rule proposal isued with final rule date of Jun22, 2001

January 2001

The EPA posted a final rule in the Federal Register, five months ahead of schedule, lowering the standard from 50 to 10 ppb.  The EPA also established a health-based, non-enforceable Maximum Contaminant Level Goal (MCLG) for arsenic of 0 ppb. 

March 2001

Under the new leadership of the Bush administration the EPA withdrew the rule. They stated that more research on cost and health effects was needed.  The effective date of the new rule was delayed until May 22, 2001. 

May 2001

The effective date was delayed again by the EPA, until February 22, 2002, stating a need for public reaction and additional research.  Studies on the benefits of a new standard, cost expectations and health effects were commissioned by the agency.  Even though under the Bush administration, the EPA refused to implement the final rule of 10 ppb, they publicly acknowledged that the standard needed to be lowered somewhere between 3 and 20 ppb. 

August  2001

Reports of the study and suggestions of the Arsenic Cost Working Group were concluded by the National Drinking Water Advisory (NDWAC) and delivered to the EPA.  The NDWAC stated that a valid evaluation of the cost of compliance was presented by the EPA, but that other treatment options, like Point-of-Use, could possibly allow smaller water systems to conform more cost-effectively. 

August  2001

The final report on the benefits of a lowered standard was given by the Science Advisory board (SAB) to the EPA.

September 2001

The results of the health effects study was released by the National Adademy of Sciences (NAS).  It was reported that the dangers of cancer are much higher than they had been previously reconized under the Clinton and Bush administrations. 

October 2001

The EPA released information on and availability of three reports ­ the health effects/science report prepared by the National Academy of Sciences, the costs report of the National Drinking Water Advisory Council, and the benefits report of the EPA’s Science Advisory Board.  These reports can be viewed online at:

NAS health effects report:

http://www.nap.edu/books/0309076293/html/

NDWAC costs report:

http://www.epa.gov/safewater/ars/ndwac-arsenic-report.pdf

SAB benefits report:

http://www.epa.gov/sab/ec01008.pdf 

October  2001

EPA announces call for public comment on the three reports by October 31, 2001.

November 2001

Official announcement by the EPA that it would lower the arsenic standard from 50 ppb to 10 ppb. 

November 2001

The bill for the new arsenic standard of 10 ppb  was signed by President George W. Bush.  Public water systems were given until 2006 to comply with the new rule.