Third Unregulated Contaminant Monitoring Rule
The 1996 Safe Drinking Water Act (SDWA) amendments require that once every five years EPA issue a new list of no more than 30 unregulated contaminants to be monitored by public water systems (PWSs).
The third Unregulated Contaminant Monitoring Rule (UCMR 3) was published on May 2, 2012. UCMR 3 required monitoring for 30 contaminants (28 chemicals and two viruses) between 2013 and 2015 using analytical methods developed by EPA, consensus organizations or both. This monitoring provides a basis for future regulatory actions to protect public health.
- Federal Register Notice: Final Revisions to the UCMR 3 for Public Water Systems, May 2, 2012
- UCMR 3 Basic Information Fact Sheet
- EPA Approved Laboratories for UCMR 3
UCMR 3 analytical methods and contaminants
- Assessment monitoring (List 1 contaminants)
- Screening survey (List 2 contaminants)
- Pre-screen testing (List 3 contaminants)
- Notes
Assessment Monitoring (List 1 contaminants)
All PWSs serving more than 10,000 people and 800 representative PWSs serving 10,000 or fewer people monitored for 21 List 1 contaminants during a 12-month period from January 2013 through December 2015.
Seven Volatile Organic Compounds
|
Contaminant |
CAS Registry Number1 |
Minimum Reporting Level |
Sampling Points2 |
Analytical Methods |
|---|---|---|---|---|
|
1,2,3-trichloropropane |
96-18-4 |
0.03 µg/L |
EPTDS |
EPA 524.3 |
|
1,3-butadiene |
106-99-0 |
0.1 µg/L |
EPTDS |
EPA 524.3 |
|
chloromethane (methyl chloride) |
74-87-3 |
0.2 µg/L |
EPTDS |
EPA 524.3 |
|
1,1-dichloroethane |
75-34-3 |
0.03 µg/L |
EPTDS |
EPA 524.3 |
|
bromomethane (methyl bromide) |
74-83-9 |
0.2 µg/L |
EPTDS |
EPA 524.3 |
|
chlorodifluoromethane (HCFC-22) |
75-45-6 |
0.08 µg/L |
EPTDS |
EPA 524.3 |
|
bromochloromethane (halon 1011) |
74-97-5 |
0.06 µg/L |
EPTDS |
EPA 524.3 |
One Synthetic Organic Compound
|
Contaminant |
CAS Registry Number1 |
Minimum Reporting Level |
Sampling Points2 |
Analytical Methods |
|---|---|---|---|---|
|
1,4-dioxane |
123-91-1 |
0.07 µg/L |
EPTDS |
EPA 522 |
Six Metals
|
Contaminant |
CAS Registry Number1 |
Minimum Reporting Level |
Sampling Points2 |
Analytical Methods |
|---|---|---|---|---|
|
vanadium |
7440-62-2 |
0.2 µg/L |
EPTDS & DSMRT |
EPA 200.8 Rev 5.4 |
|
molybdenum |
7439-98-7 |
1 µg/L |
EPTDS & DSMRT |
EPA 200.8 Rev 5.4, ASTM D5673-10, Standard Methods 3125 (1997) |
|
cobalt |
7440-48-4 |
1µg/L |
EPTDS & DSMRT |
EPA 200.8 Rev 5.4, ASTM D5673-10, Standard Methods 3125 (1997) |
|
strontium |
7440-24-6 |
0.3 µg/L |
EPTDS & DSMRT |
EPA 200.8 Rev 5.4, ASTM D5673-10, Standard Methods 3125 (1997) |
|
chromium3 |
Not applicable. |
0.2 µg/L |
EPTDS & DSMRT |
EPA 200.8 Rev 5.4, ASTM D5673-10, Standard Methods 3125 (1997) |
|
chromium-6 |
18540-29-9 |
0.03 µg/L |
EPTDS & DSMRT |
EPA 218.7 |
One Oxyhalide Anion
|
Contaminant |
CAS Registry Number1 |
Minimum Reporting Level |
Sampling Points2 |
Analytical Methods |
|---|---|---|---|---|
|
chlorate |
14866-68-3 |
20 µg/L |
EPTDS & DSMRT |
EPA 300.1, ASTM D6581-08, Standard Methods 4110D (1997) |
Six Perfluorinated Compounds
|
Contaminant |
CAS Registry Number1 |
Minimum Reporting Level |
Sampling Points2 |
Analytical Methods |
|---|---|---|---|---|
|
perfluorooctanesulfonic acid (PFOS) |
1763-23-1 |
0.04 µg/L |
EPTDS |
EPA 537 Rev 1.1 |
|
perfluorooctanoic acid (PFOA) |
335-67-1 |
0.02 µg/L |
EPTDS |
EPA 537 Rev 1.1 |
|
perfluorononanoic acid (PFNA) |
375-95-1 |
0.02 µg/L |
EPTDS |
EPA 537 Rev 1.1 |
|
perfluorohexanesulfonic acid (PFHxS) |
355-46-4 |
0.03 µg/L |
EPTDS |
EPA 537 Rev 1.1 |
|
perfluoroheptanoic acid (PFHpA) |
375-85-9 |
0.01 µg/L |
EPTDS |
EPA 537 Rev 1.1 |
|
perfluorobutanesulfonic acid (PFBS) |
375-73-5 |
0.09 µg/L |
EPTDS |
EPA 537 Rev 1.1 |
Screening Survey (List 2 contaminants)
All PWSs serving more than 100,000 people, 320 representative PWSs serving 10,001 to 100,000 people, and 480 representative PWSs serving 10,000 or fewer people monitored for seven List 2 contaminants during a 12-month period from January 2013 through December 2015.
Seven Hormones
|
Contaminant |
CAS Registry Number1 |
Minimum Reporting Level |
Sampling Points2 |
Analytical Methods |
|---|---|---|---|---|
|
17-β-estradiol |
50-28-2 |
0.0004 µg/L |
EPTDS |
EPA 539 |
|
17-α-ethynylestradiol (ethinyl estradiol) |
57-63-6 |
0.0009 µg/L |
EPTDS |
EPA 539 |
|
16-α-hydroxyestradiol (estriol) |
50-27-1 |
0.0008 µg/L |
EPTDS |
EPA 539 |
|
equilin |
474-86-2 |
0.004 µg/L |
EPTDS |
EPA 539 |
|
estrone |
53-16-7 |
0.002 µg/L |
EPTDS |
EPA 539 |
|
testosterone |
58-22-0 |
0.0001 µg/L |
EPTDS |
EPA 539 |
|
4-androstene-3,17-dione |
63-05-8 |
0.0003 µg/L |
EPTDS |
EPA 539 |
Pre-Screen Testing (List 3 contaminants)
EPA selected 800 representative PWSs that serve 1,000 or fewer people, do not disinfect, and have wells located in areas of karst or fractured bedrock to monitor for two List 3 viruses during a 12-month period from January 2013 through December 2015.
Two Viruses
|
Contaminant |
CAS Registry Number1 |
Minimum Reporting Level |
Sampling Points2 |
Analytical Methods |
|---|---|---|---|---|
|
enteroviruses |
Not Applicable. |
Not Applicable. |
EPTDS |
EPA 1615 |
|
noroviruses |
Not Applicable. |
Not Applicable. |
EPTDS |
EPA 1615 |
Notes
- Chemical Abstract Service (CAS) Registry Number
- Sample points:
- Entry points to the distribution system (EPTDS)
- Distribution system maximum residence time (DSMRT)
- Monitoring for total chromium in conjunction with UCMR 3 assessment monitoring is required under the authority provided in Section 1445(a)(1)(A) of the SDWA.