Contact Information
- Phone
- 530-757-5686
- water@cityofdavis.org
- Address
- Public Works Corporation Yard
- 1717 Fifth Street, Davis, CA 95616
- Hours
- Monday – Friday
- 7:00am to 3:30pm
Access to the corporation yard is by phone call or appointment only.
City of Davis, CA
Home MenuUCMR 5 Sampling
Unregulated Contaminant Monitoring Rule
Every five years, the U.S. Environmental Protection Agency (US EPA) requires Public Water Systems to test their source water(s) for unregulated contaminants. Unregulated contaminant monitoring helps US EPA and the State Water Resources Control Board to determine where certain contaminants occur and whether the contaminants need to be regulated. In 2024, the City started sampling for the Unregulated Contaminant Monitoring Rule 5 (UCMR5). This rule requires sampling at the entry points to the water distribution system for 29 per- and polyfuoroalkyl substances (PFAS) or “forever chemicals” and lithium. The entry points to the distribution system for the City of Davis are at the point of entry for treated surface water and at select well sites that represent the treated groundwater.
The following is the list of constituents sampled for during UCMR5:
|
Contaminant |
Minimum Reporting Level (ug/L) |
Additional Information |
|
11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) |
0.005 |
PFAS are a group of synthetic chemicals used in a wide range of consumer products and industrial applications including: non-stick cookware, water-repellent clothing, stain-resistant fabrics and carpets, cosmetics, firefighting foams, electroplating and products that resist grease, water and oil. PFAS are found in the blood of people and animals and in water, air, fish and soil at locations across the United States and the world.
|
|
1H,1H, 2H, 2H-perfluorodecane sulfonic acid (8:2FTS) |
0.005 |
|
|
1H,1H, 2H, 2H-perfluorohexane sulfonic acid (4:2FTS) |
0.003 |
|
|
1H,1H, 2H, 2H-perfluorooctane sulfonic acid (6:2FTS) |
0.005 |
|
|
4,8-dioxa-3H-perfluorononanoic acid (ADONA) |
0.003 |
|
|
9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS) |
0.002 |
|
|
hexafluoropropylene oxide dimer acid (HFPO-DA)(GenX) |
0.005 |
|
|
nonafluoro-3,6-dioxaheptanoic acid (NFDHA) |
0.02 |
|
|
perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) |
0.003 |
|
|
perfluoro-3-methoxypropanoic acid (PFMPA) |
0.004 |
|
|
perfluoro-4-methoxybutanoic acid (PFMBA) |
0.003 |
|
|
perfluorobutanesulfonic acid (PFBS) |
0.003 |
|
|
perfluorobutanoic acid (PFBA) |
0.005 |
|
|
perfluorodecanoic acid (PFDA) |
0.003 |
|
|
perfluorododecanoic acid (PFDoA) |
0.003 |
|
|
perfluoroheptanesulfonic acid (PFHpS) |
0.003 |
|
|
perfluoroheptanoic acid (PFHpA) |
0.003 |
|
|
perfluorohexanesulfonic acid (PFHxS) |
0.003 |
|
|
perfluorohexanoic acid (PFHxA) |
0.003 |
|
|
perfluorononanoic acid (PFNA) |
0.003 |
|
|
perfluorooctanesulfonic acid (PFOS) |
0.004 |
|
|
perfluorooctanoic acid (PFOA) |
0.004 |
|
|
perfluoropentanesulfonic acid (PFPeS) |
0.004 |
|
|
perfluoropentanoic acid (PFPeA) |
0.003 |
|
|
perfluoroundecanoic acid (PFUnA) |
0.002 |
|
|
N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) |
0.005 |
|
|
N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) |
0.006 |
|
|
perfluorotetradecanoic acid (PFTA) |
0.008 |
|
|
perfluorotridecanoic acid (PFTrDA) |
0.007 |
|
|
lithium |
9 |
Naturally occurring metal; lithium salts are used as pharmaceuticals, used in electrochemical cells, batteries and in organic syntheses. |
The table below lists the unregulated constituents that were detected during UCMR5 sampling events. The US EPA uses the data from UCMR sampling events to develop potential regulation on these constituents.
|
Constituent |
Unit |
Year Sampled |
Range |
|
lithium |
ug/L |
2024 |
<MRL – 37 |
Lithium has been detected in the groundwater wells but has not been detected in the treated surface water. Lithium is a naturally occurring metal in the Earth’s crust. Currently, there is no regulatory limit or health advisory for lithium in drinking water. If you would like to learn more about lithium regulations, please see the US EPA website.