The EPA’s UCMR Program


The EPA is a much busier agency than most people think.

In addition to looking after currently regulated drinking water contaminants through its familiar list of MCLs,  the EPA maintains a Contaminant Candidate List (CCL) comprised of other contaminants that may be subject to future regulation.  The public is not so aware of the CCL.

CCL-listed contaminants include those that have been found in drinking water at Public Water Supplies (PWSs),  or others that have been identified through EPA research.  Contaminants on the list are prioritized based on their potential health risk to humans,  as assessed by the EPA’s Office of Water’s Office of Science and Technology.

In other words, the CCL list consists of currently unregulated contaminants and the purpose of monitoring is to determine if further regulation is appropriate.

Now (to make this a bit more confusing with yet another acronym), the CCL is managed under  an EPA program known as its Unregulated Contaminant Monitoring program (UCMR) .

The UCMR program requires the EPA to issue a list every five years of not more than 30 currently unregulated contaminants to be monitored by PWSs.

The new list is actually the third issued since the program’s inception.  UCMR 3 , initiated in April 2012,  will monitor 30 new additional contaminants (28 chemicals and two viruses) during the period from 2013 to 2015.


Assessment Monitoring (List 1 Contaminants)

Under UCMR3,  all PWSs serving more than 10,000 people, along with 800 EPA-selected PWSs serving 10,000 or fewer people, will be required to monitor 21 separate contaminants. The contaminant list includes seven different volatile organic compounds, six different metals, six perfluorinated compounds, one synthetic organic compound and one oxyhalide anion.  Specific List 1 contaminants to be monitored include some familiar names and some that are not so familiar:

• 1,2,3 — trichloropropane

• 1,3 — butadiene

• chloromethane (methyl chloride)

• 1,1 — dichloroethane

• bromomethane (methyl bromide)

• chlorodifluoromethane (HCFC—22)

• bromochloromethane (halon 1011)

• 1,4 — dioxane

• vanadium

• molybdenum

• cobalt

• chromium

• chromium-6

• chlorate

• perfluorooctanesulfonic acid (PFOS)

• perfluorooctanoic acid (PFOA)

• perfluorononanoic acid (PFNA)

• perfluorohexanesulfonic acid (PFHxS)

• perfluoroheptanoic acid (PFHpA)

• perfluorobutanesulfonic acid (PFBS)

• strontium

For the full report on the additional complexities of UCMR3.