1

CHROMIUM PLUME

UPDATE

Since the Late Summer 2013 DECP News Chromium Informa-

tion Special Edition, DECP has been working with DOE, LANL

and NMED in discussions about possible paths forward. Topics

have included:

LANL drilling wells on their land to discover the boundaries

of the chromium plume

LANL drilling wells on their land to pump out contaminated

ground-water

LANL treating the contaminated groundwater

LANL injecting the treated water back into the ground on

their land

LANL consulting with San Ildefonso regarding POSSIBLY

drilling a well on San Ildefonso land, to monitor any possi-

ble movement of the chromium in the regional aquifer be-

neath San Ildefonso land.

DECP will continue to communicate with DOE, LANL and NMED

in order to protect the lands, interests, and culture of the people

of the Pueblo de San Ildefonso.

DECP decided to create this

“special edition” newsletter to

not only specifically address

some of the questions raised,

but also to provide additional

background information about

scientific concepts . It is our

goal to help Tribal members

better understand the nature

of any risk to themselves or

their families through the tra-

ditional use of natural re-

sources on the Pueblo.

This newsletter is designed to

be an introduction to key con-

cepts concerning issues raised

at the community meeting,

and is not designed to be a

complete reference.

MORE FORMAITON,

PLEASE CONTACT THE

DECP OFFICE @ 455-4121

MISSION

2014 - UPDATE

What is chromium?

> > > > > >

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DECP NEWS - 2014 UPDATE Page 2

Chromium Edition

Chromium is the 24th most abundant element in the Earth’s crust and chromium compounds are found in

the environment, due to erosion of chromium-containing rocks and can be distributed by volcanic eruptions.

It is a tasteless, odorless, silvery metal which is found naturally in primarily two forms, Cr(III) and Cr(VI). The ratio

of Cr(III) to Cr(VI) largely depends on the pH (acidity) and presence of oxygen in the immediate environment1.

How do you measure chromium? Chromium is measured in “micrograms” (µg), or “parts per billion” (ppb). One ppb represents one microgram of

something per liter of water (ug/l). Put another way, the state drinking water standard for chromium of 50 ppb repre-

sents the weight of an average “smart phone” (4.4 oz,) per Olympic size swimming pool.

Is it toxic? Trivalent chromium (Cr(III) or Cr3+) occurs naturally in trace amounts in many vegetables, fruits,

meats, grains and yeast, and is considered not toxic, except at very high exposure levels. The

United States dietary guidelines for daily chromium uptake for an adult are 35 µg (adult male)

and 25 µg (adult female), and chromium is often included in dietary supplements and multi-

vitamins2. The general population is exposed to chromium (generally chromium [III]) by eating

food, drinking water, and inhaling air that contains the chemical. The average daily intake from

air, water, and food is estimated to be less than 0.2 to 0.4 µg, 2.0 µg, and 60 µg, respectively3.

In contrast, hexavalent chromium (Cr(VI) or Cr6+) is considered toxic and carcinogenic when inhaled or ingested

in sufficient quantities4.

It creates toxicity and cancer in the lungs (inhaled), liver, kidneys, and intestines.

It increases the chance of failed pregnancy, reduced birth weight, and deformities.

It can cause a reduction of fertility in both men and women.

Women may be at a higher risk than men.

Children and pregnant women are at a higher risk.

What is the drinking water standard for Chromium? Current drinking water standards do not separate the two forms because they can change back and forth inside the hu-

man body. Instead, the current standards assume that all chromium found is in the toxic Cr(VI) form. This assumption

creates a “conservative” estimate.

In 1991, the US Environmental Protection Agency (EPA) established a drinking water standard for chromium at 100

ppb, based on scientific evidence showing allergic skin reactions from continued exposure. Since then, the EPA has

How do we use chromium? Chromium compounds are used in many ways. They are used to create dyes and pigments

for paints and primers (yellow school buses), treat wood against fungi, decay and termites,

and have many applications in industry due to their usefulness in the tanning of leather

and preventing the corrosion of metal. Stainless steel for instance, which can be found in

most kitchens, usually includes at least 11% chromium. Chrome plating on automobiles

is another common application, used to prevent oxidation of the metal (rust)1.

The state of New Mexico has a lower drinking water standard of 50 ppb. This is the stan-

dard at which DOE/LANL is regulated by the state of New Mexico6. The closest drinking

water well on the Pueblo is 4 miles away from the chromium plume, and remains unaf-

fected.

Chromium

adds the

green and

red colors to

emeralds and

rubies

Stainless

steel

(chromium)

utensils

3

What is an aquifer?

An aquifer is an underground layer of sand, gravel and/or rock from which water can be extracted. The water is not

separate from the rocks, like a lake or river, but fills all the spaces between the rocks; like a bathtub filled with different

sized marbles. There are different kinds of aquifers which can be described by relative depth, material, and general rate

of flow.

Alluvial aquifers are fairly close to the surface beneath a river or drainage. The water in an alluvial aquifer tends to

move fairly quickly, because the ground beneath is mostly sand and gravel.

As water goes deeper, it may encounter material such as solid rock, or a thick layer of clay, which “confines” the water,

or keeps it separated from the other layers. The water continues to move, but usually much slower, and can take on dif-

ferent characteristics than surrounding water layers; such as different dissolved mineral concentrations. This is called a

“perched” aquifer.

Finally, water can reach the “regional” aquifer. The regional aquifer can be quite deep. In Sacred Area for instance, it

is around 1000 feet below the surface. The time it takes for water to reach the regional aquifer depends on the path it

takes. Some water samples beneath the Pajarito Plateau have been estimated to be 35,000 years old and believed to

come from the Sangre de Cristo Mountains7. Other samples are less than 50 years old, such as the chromium plume be-

neath Mortandad Can-

yon.

The diagram below illus-

trates many of the com-

ponents of Pajarito Pla-

teau geology. As you

can see, the ground be-

neath the Plateau is com-

plicated, with several

different rock formations.

This makes it difficult to

determine which path,

and how long it takes for

water to reach the re-

gional aquifer.

DECP NEWS - 2014 UPDATE Page 3

Chromium Edition

Since then, the EPA has conducted research showing that Cr(VI) may cause cancer when ingested, and is currently in

the process of reviewing this information, and possibly changing the standard in the future5.

The state of New Mexico has a lower drinking water standard of 50 ppb. This is the standard at which DOE/LANL is

regulated by the state of New Mexico6. The closest drinking water well on the Pueblo is 4 miles away from the chro-

mium plume, and remains unaffected.

Can I be exposed to chromium by being in Sacred Area? No. The chromium plume is about 1000 feet under-

ground. Plants, animals and people on the surface

cannot be exposed to it.

Is chromium radioactive like pluto-nium, or transuranic waste? No. Chromium is not radioactive. In order to be ex-

posed to chromium, it must be inhaled, ingested, or

come into direct contact with the skin.

4

Where is the chromium now?

In 2005, LANL detected Cr(VI) through routine monitoring in a new well (R-28). Since then they have

worked with the State of New Mexico Environment Department (NMED) to determine the nature and extent

(how bad and how big) of the chromium contamination. Below is a map of the surrounding area showing the

LANL / San Ildefonso Pueblo border and where the plume is believed to be currently located.Each of the red

and green diamonds represent wells drilled at different depths and monitored by LANL. The blue shape repre-

sents the estimated size and shape of the chromium plume with concentrations above the state standard of 50

parts per billion (ppb). The purple boundary represents another plume of perchlorate, at much lower levels,

but still above the state

screening level of 4

ppb. It is believed that

the chromium plume is

continuing to move

slowly to the southeast

towards San Ildefonso

Pueblo.

The chromium and

perchlorate plumes

are 1000 feet below

the surface. Hu-

mans, animals or

plants in “Sacred

Area” cannot be di-

rectly contaminated

by it.

DECP NEWS - 2014 UPDATE Page 4

Chromium Edition

Why is there chromium in the regional aquifer?

From 1956—1972 LANL was using chromium compounds to prevent corrosion in the cooling towers at the Labora-

tory power plant. LANL estimates that around 160,000 pounds were released in hexavalent, Cr(VI) form during that

time. The cooling tower water was routinely discharged into Sandia Canyon (bottom right). The continued presence

of water in a normally dry canyon allowed for the creation of a wetland in that location (bottom left). The wetland

captured much of the chromium released because of its anoxic (no oxygen) environment by reducing the toxic Cr

(VI) to much less mobile and less toxic Cr(III). Some of the water which continued to flow through the wetland still

contained hexavalent chromium however. It is believed that the water stayed close to the surface as it moved down

the canyon for a couple miles before finding a way through the fractures in the underlying rock. Over the course of

40 years it eventually made it to the regional aquifer 1000 feet below the surface. In order to keep the chromium

from leaving the wetland, water needs to continue to flow through it. LANL knows this, and makes sure that enough

clean water flows into the wetland to keep it healthy.

San Ildefonso Pueblo Boundary

5

DECP NEWS - 2014 UPDATE Page 5

Chromium Edition

What is being done to clean it up?

Since LANL discovered the plume in 2005:

They are currently running a “pump and treat” test on two of the wells this summer.

They are pumping the contaminated water from the aquifer, filtering out the chro-

mium and then spraying the clean water on the ground; allowing it to evaporate.

This process has been approved by the New Mexico Environment Department

(NMED).

Based on their findings from the test, they will propose a clean up solution to

NMED by next spring.

The graph above shows projected vs. actual water pumped and treated as of the end of July.

The total amount of water pumped and treated this summer will depend on the weather, be-

cause they will need to stop pumping before freezing temperatures begin. However, based

on a current estimate of almost 4 million gallons, it roughly equates to the volume of 6

Olympic size swimming pools.

They have created structures to stabilize the

wetland from eroding, while keeping

enough water in the wetland to maintain an

environment which retains the chromium.

This will help to prevent any more chro-

mium from being released.

They have drilled several new wells to de-

termine the nature and extent of the chro-

mium plume, as shown in the previous map.

References

Raymond Martinez

Director/Tribal Risk

Assessment Program

Manager

Michael Chacon

Technical Reviewer/

QA Manager

Erin Martinez

Office Administrator

Noah Kaniatobe

GPS\GIS Technician

Eric Archuleta

Database Manager

Alexander King

Water Quality

Technician

Bryan Montoya

Cultural Resources Advisor/WIPP

Coordinator

Raymond Martinez

Director/Tribal Risk

Assessment Program

Manager

Michael Chacon

Technical Reviewer/

QA Manager

Erin Martinez

Office Administrator

Noah Kaniatobe

GPS\GIS Technician

Eric Archuleta

Database Manager

Alexander King

Water Quality

Technician

Bryan Montoya

Cultural Resources Advisor/WIPP

Coordinator

1. Chromium. (2013, July 27). In Wikipedia, The Free Encyclopedia. Retrieved August 16, 2013,

from http://en.wikipedia.org/w/index.php?title=Chromium&oldid=565959726

2. Chromium. (2005, August 5). In Dietary Supplement Fact Sheet, Office of Dietary Supplements,

National Institute of Health. Retrieved August 16, 2013, from

http://ods.od.nih.gov/factsheets/Chromium-HealthProfessional/

1. Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Chro-

mium. U.S. Public Health Service, U.S. Department of Health and Human Services, Atlanta,

GA. 1998.

4. U.S. EPA. IRIS Toxicological Review of Hexavalent Chromium (2010 External Review Draft).

U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-10/004A, 2010.

5. U.S. EPA. (2012, April 18). In Chromium in Drink Water. Retrieved August 16, 2013, from

http://water.epa.gov/drink/info/chromium/index.cfm

6. New Mexico State 20.6.2 NMAC. Retrieved August 16, 2013.

7. Rogers et al. 1996. Recharge to the Pajarito Plateau Regional Aquifer System. New Mexico

Geological Society Guidebook, 47th Field Conference, Jemez Mountains Region.