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Understanding Emerging Compounds Helps Us Keep Your Water Clean and Safe

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)

Reference Concentration (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 isposted on EPA's UCMR website.

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