**Click here for 2014 PFAS test results**
DC Water and approximately 6,000 other water utilities in the country monitor for unregulated compounds in accordance with EPA's fourth Unregulated Contaminant Monitoring Rule (UCMR4). This information will help EPA determine if regulation is necessary to protect public health, and it will help DC Water and other public water systems determine how to address the issue of emerging compounds.
Learn more about our UCMR4 compliance here.
Definitions:
- Minimum Reporting Levels (MRLs) are derived from the capability of the anayltical method. Learn more about EPA's process here.
- Maximum Contaminant Levels (MCLs) are the highest levels of a contaminant that is allowed in drinking water. This is a drinking water regulation enforced by EPA. Learn more about EPA's standards here.
- Health Advisory Levels are estimated acceptable levels of a contaminant in drinking water based on health effects information. They are not regulations, but serve as technical guidance from EPA. Learn more about EPA's standards here.
- Reference Concentrations are health-based levels above which adverse health effects have been documented. They are not regulations, and not all contaminants have reference concentrations. Learn more about EPA's process here.
Detected Compounds (µg/L, or parts per billion)
1 microgram per Liter (µg/L), or 1 part per billion (ppb) is the equivalent of a few drops of water in an Olympic-sized swimming pool.
|
Contaminant |
Minimum Reporting Level (µg/L) |
Maximum Contaminant Level (µg/L) |
Detected Concentration (µg/L) |
Dalecarlia Treatment Plant Entry Point |
McMillan Treatment Plan Entry Point |
Distribution System |
Common Sources |
|
HAA5 |
NA |
60 |
Range (min-max) |
- |
- |
5.5-66.0 |
By-product of drinking water disinfection. See our FAQ. |
|
Average |
- |
- |
34.5 |
||||
|
HAA6Br |
NA |
NA |
Range (min-max) |
- |
- |
0.5-12.6 |
By-product of drinking water disinfection. See our FAQ. |
|
Average |
- |
- |
42.4 |
||||
|
HAA9 |
NA |
NA |
Range (min-max) |
- |
- |
6.0-74.4 |
By-product of drinking water disinfection. See our FAQ. |
|
Average |
- |
- |
42.4 |
||||
|
Manganese |
0.4 |
NA* |
Range (min-max) |
0.7-1.2 |
- |
- |
Naturally-occurring element and essential nutrient that can be found ubiquitously in the air, soil, and water. Manganese is commercially available in combination with other elements and minerals; used in steel production, fertilizer, batteries and fireworks; drinking water and wastewater treatment chemical. |
|
Average |
0.9 |
- |
- |
*Manganese has a drinking water lifetime health advisory level of 300 µg/L, below which, no adverse health effects are expected to occur. Detected levels of manganese were over 300 times lower than this level.
Undetected Unregulated Compounds (µg/L, or parts per billion)
None of the contaminants below were detected in drinking water.
|
Contaminant |
Minimum Reporting Level (µg/L) |
Dalecarlia Treatment Plant Entry Point |
McMillan Treatment Plan Entry Point |
Distribution System |
Common Sources |
|
|
Germanium |
0.03 |
NA |
Non-detect |
Non-detect |
- |
A naturally-occurring element and is commonly found as germanium dioxide in phosphors, transistors and diodes, and in electroplating. In some cases, it has been sold as a dietary supplement. |
|
Alpha-hexachlorocyclohexane |
0.01 |
0.006 to 0.6 |
Non-detect |
Non-detect |
- |
A component of benzene hexachloride (BHC); was formerly used as an insecticide. |
|
Chlorpyrifos |
0.03 |
2 |
Non-detect |
Non-detect |
- |
An organophosphate insecticide, acaricide, and miticide. |
|
Dimethipin |
0.02 |
140 |
Non-detect |
Non-detect |
- |
An herbicide and plant growth regulator. |
|
Ethoprop |
0.03 |
1.14 to 114 |
Non-detect |
Non-detect |
- |
An insecticide. |
|
Oxyfluorfen |
0.05 |
200 |
Non-detect |
Non-detect |
- |
An herbicide. |
|
Profenofos |
0.03 |
0.03 |
Non-detect |
Non-detect |
- |
An insecticide and acaricide. |
|
Tebuconazole |
0.2 |
0.2 |
Non-detect |
Non-detect |
- |
A fungicide. |
|
Total permethrin |
0.04 |
3.344 to 334.4 |
Non-detect |
Non-detect |
- |
An insecticide. |
|
Tribufos |
0.07 |
0.06 |
Non-detect |
Non-detect |
- |
An insecticide and used as a cotton defoliant. |
|
Butylated hydrooxyanisole |
0.03 |
NA |
Non-detect |
Non-detect |
- |
Used as a food additive (antioxidant). |
|
o-toluidine |
0.007 |
NA |
Non-detect |
Non-detect |
- |
Used in the production of dyes, rubber, pharmaceuticals and pesticides. |
|
Quinoline |
0.02 |
0.01 to 1 |
Non-detect |
Non-detect |
- |
A component of coal tars and used in the production of other substances, and as a pharmaceutical (anti-malarial). |
|
1-butanol |
2.0 |
700 |
Non-detect |
Non-detect |
- |
A solvent and used in production of other chemicals. It is present in a number of commercial products such as perfumes. |
|
2-methoxyethanal |
0.4 |
NA |
Non-detect |
Non-detect |
- |
Used in a number of consumer products, such as synthetic cosmetics, perfumes, fragrances, hair preparations, and skin lotions. |
|
2-propen-1-ol (allyl alcohol) |
0.5 |
35 |
Non-detect |
Non-detect |
- |
Used in the production of other chemicals. |
Undetected Unregulated Compounds (µg/L, or parts per billion)
None of the contaminants below were detected in drinking water.
|
Contaminant |
Minimum Reporting Level (µg/L) |
Health Advisory Level (µg/L) |
Dalecarlia Treatment Plant Entry Point |
McMillan Treatment Plan Entry Point |
Distribution System |
Common Sources |
|
Total Microcystins |
0.03 |
0.3 infants and children; 1.6 for adults |
Non-detect |
Non-detect |
- |
Produced by naturally-occurring photosynthetic bacteria, see our FAQ |
|
Nodularin-R |
0.005 |
NA |
Non-detect |
Non-detect |
- |
Produced by naturally-occurring photosynthetic bacteria, see our FAQ |
|
Anatoxin-a |
0.03 |
NA |
Non-detect |
Non-detect |
- |
Produced by naturally-occurring photosynthetic bacteria, see our FAQ |
|
Cylindrospermopsin |
0.09 |
0.7 for children; 3.0 for adults |
Non-detect |
Non-detect |
- |
Produced by naturally-occurring photosynthetic bacteria, see our FAQ |
UCMR3
DC Water and approximately 6,000 other water utilities in the country monitored for unregulated compounds in accordance with EPA's third Unregulated Contaminant Monitoring Rule (UCMR3). To comply with the UCMR3, DC Water conducted these tests quarterly in 2014. The results of all testing conducted by water utilities are posted on EPA's UCMR website.
In 2014 as part of this testing, DC Water and other utilities that use water from the Potomac River tested drinking water supplies for several PFAS. No detectable levels of these compounds were found in D.C.’s drinking water. Newer, more precise methods of testing have been developed since the 2014 testing to detect very low levels of PFAS. The Environmental Working Group recently released a study which detected PFAS in District drinking water at levels well below any established EPA health advisory for these compounds. Please see our frequently asked questions.
Below is a summary of testing results. Click here to download the data.
Detected Unregulated Compounds (parts per billion)
| Compound | Date Sampled | Dalecarlia Water Treatment Plant Entry Point | Distribution System Sample 1 (Dalecarlia) | McMillan Water Treatment Plant Entry Point | Distribution System Sample 2 (McMillan) | Common Sources |
|---|---|---|---|---|---|---|
| Chlorate | January 2014 | 210 | 200 | 160 | 160 | Byproduct of the water disinfection process and ingredient in herbicides and explosives. |
| April 2014 | 140 | 170 | 120 | 120 | ||
| July 2014 | 430 | 470 | 250 | 250 | ||
| October 2014 | 330 | 340 | 410 | 410 | ||
| Chromium | July 2014 | 0.20 | No Detection | 0.24 | No Detection | Naturally ocurring element that can be found in soils, plants, rocks, water and animals. |
| October 2014 | 0.26 | 0.31 | 0.36 | 0.32 | ||
| Chromium - 6 | January 2014 | 0.091 | 0.077 | 0.082 | 0.074 | Ingredient in some paint and industrial products, such as metal coatings. |
| April 2014 | 0.092 | 0.12 | 0.075 | 0.077 | ||
| July 2014 | 0.098 | 0.10 | 0.10 | 0.10 | ||
| October 2014 | 0.063 | 0.076 | 0.077 | 0.079 | ||
| Molybdenum | October 2014 | 1.0 | 1.1 | 1.2 | 1.2 | Naturally-occurring metal that can be found in rocks and soil. It is also present in plants, animals and bacteria. Molybdenum is most commonly used in the production of structural steel, stainless steel, cast iron and other alloys. |
| Strontium | January 2014 | 160 | 140 | 130 | 120 | Occurs naturally in the environment but can be released at higher levels from industrial processes, such as coal burning and fertilizer manufacturing. |
| April 2014 | 130 | 120 | 120 | 120 | ||
| July 2014 | 24 | 210 | 200 | 190 | ||
| October 2014 | 220 | 230 | 260 | 260 | ||
| Vanadium | April 2014 | 0.22 | 0.20 | No Detection | No Detection | Occurs naturally in many minerals and fossil fuel deposits. The primary industrial use is strengthening steel. |
| July 2014 | 1.3 | 0.85 | 0.57 | 0.55 | ||
| October 2014 | 0.60 | 0.57 | 0.40 | 0.39 |
| Compound | Date Sampled | Dalecarlia Water Treatment Plant Entry Point | McMillan Water Treatment Plant Entry Point | Common Sources |
| perfluorooctanesulfonic (PFOS) | January 2014 | No Detection | No Detection | Surfactant or emulsifier; used in fire-fighting foam, circuit board etching acids, alkaline cleaners, floor polish, and as a pesticide active ingredient for insect bait traps. U.S. manufacture of PFOS phased out in 2002, however, PFOS are still generated incidentally. |
| April 2014 | No Detection | No Detection | ||
| July 2014 | No Detection | No Detection | ||
| October 2014 | No Detection | No Detection | ||
| perfluorooctanoic acid (PFOA) | January 2014 | No Detection | No Detection | Perfluorinated aliphatic carboxylic acid; used for its emulsifier and surfactant properties in or as fluoropolymers (such as Teflon), fire-fighting foams, cleaners, cosmetics, greases and lubricants, paints, polishes, adhesives and photographic films. |
| April 2014 | No Detection | No Detection | ||
| July 2014 | No Detection | No Detection | ||
| October 2014 | No Detection | No Detection | ||
| perfluorononanoic acid (PFNA) | January 2014 | No Detection | No Detection | Manmade chemical; used in products to make them stain, grease, heat and water resistant. |
| April 2014 | No Detection | No Detection | ||
| July 2014 | No Detection | No Detection | ||
| October 2014 | No Detection | No Detection | ||
| perfluorohexanesulfonic acid (PFHxS) | January 2014 | No Detection | No Detection | Manmade chemical; used in products to make them stain, grease, heat and water resistant. |
| April 2014 | No Detection | No Detection | ||
| July 2014 | No Detection | No Detection | ||
| October 2014 | No Detection | No Detection | ||
| perfluoroheptanoic acid (PFHpA) | January 2014 | No Detection | No Detection | Manmade chemical; used in products to make them stain, grease, heat and water resistant. |
| April 2014 | No Detection | No Detection | ||
| July 2014 | No Detection | No Detection | ||
| October 2014 | No Detection | No Detection | ||
| perfluorobutanesulfonic acid (PFBS) | January 2014 | No Detection | No Detection | Manmade chemical; used in products to make them stain, grease, heat and water resistant. |
| April 2014 | No Detection | No Detection | ||
| July 2014 | No Detection | No Detection | ||
| October 2014 | No Detection | No Detection |
