1. Why Should We Care About
Mercury Deposition?
David Gay
Illinois State Water Survey
University of Illinois
Champaign, IL
(217)

2. Goal of this Presentation….
Describe the issues surrounding the mercury problem, and
Introduce you to how we operate and measure wet deposition (& dry deposition).

3. Why Monitor for Mercury in Precipitation? Issues Surrounding Mercury

4. NWQMN’s “Relevant Questions”
2. Which water quality-related coastal resource management issues would be addressed by the Network?
Examples
Excessive algal growth, loss of aquatic vegetation
Toxic chemicals in food chains, and fish consumption advisories
Protracted, recurring or episodic hypoxic (or anoxic) conditions
Habitat loss or impairment affecting propagation of fish and wildlife resources
Harmful algal blooms that pose human health risks
Beach and shellfish bed closures
Impacts of extreme natural events and climate change
Quantity and trends in freshwater delivery, groundwater contamination, and atmospheric deposition of contaminants.

5. Problems NWQMN is Designed to Address
…. improving the water quality of our streams, estuaries and coastal waters…
…. 22,000 waterbodies are not attaining their designated uses …
Transport of contaminants from non-point sources:
Atmospheric Deposition – rapid and long-range transport of certain pollutants
Groundwater flow – wide range of residence time
Seepage from on-site waste treatment -- septic systems
Agricultural drainage -- fertilizer and manure applications
Runoff from coastal watersheds
Riverine transport from upland watersheds –gathering pollutants from multiple sources
others….

6. The mercury problem? Bioaccumulation
Through Fall
(wet+dry)
Dry Deposition
Wet Deposition
Geologic Sources
(soil, rock, base flow etc.)
Litter Fall
Water Body Hg Hg Hg
Me-Mercury Concentration
Methylation
predatory fish
Bacterial action
(water and sediment)
Zooplankton
Small fish

7. Why monitor for Mercury in Precipitation?
Atmospheric transport and deposition is the dominant pathway to most aquatic ecosystems.
Between 40 and 75% of the mercury input to lakes and streams is by wet deposition
most falls into water;
<20% of catchment deposition reaches lake
probably less in the West.
(Sorensen et al., 1997; Scherbatskoy et al., 1997; Lamborg et al., 2005; Mason et al., 1997)
“New” mercury is more likely converted to organic form than “old” mercury (preliminary, METAALICUS)

8. How Mercury is Wet Deposited
Hgp
RGM
RGM
Hgo
Hgo
Hgp
rainout
Hgp
RGM
washout

9. How Mercury is Wet Deposited
RGM
Oxidation
Hgo
Oxidation
RGM

10. Atmospheric Mercury Species Abundance
Hg0 – Elemental Mercury
(lifetime up to 1 year)
RGM – Reactive Gaseous Mercury
(lifetime hours to days)
Typical Atm. Mercury
Species Abundance
ng/m3
Hgp – Particulate Bound Mercury
(lifetime hours to days)

11. Many Mercury Sources Volcanoes (St. Helens) Enriched ores/soils
Tectonic (plate) boundaries
Cinnabar (HgS), taconite, others
Soil surfaces (0.5 ppm in crust)
Fresh water and oceans
Forests (surfaces and stomates)
Forest fires
(wood fire places?)
Tree bark, volatilization from rocks?
Coal combustion (Power 50t/yr)
Incineration
Industrial emissions
chlor-alkali
cement production (lime)
Hg use in mining and mining of Hg
Automobile Recycling
Mercury in Landfills
fluorescent lamps
dental amalgams (also in sewers)
thermometers, batteries
electrical switches
Taconite mining
low-grade iron ore, a flintlike rock usually containing less than 30% iron. Resistant to drilling and to the extraction of its contained metal, the rock was long considered worthless. Experiments begun in 1912 by the American scientist Edward W. Davis and continued by him for nearly 40 years produced the pelletizing method for upgrading the ore. The development of the jet piercer (a high-temperature flame thrower) provided penetration speeds of up to 40 ft (12 m) an hour for blasting holes in the rock. In 1956 exploitation of the vast reserves of taconite in the Mesabi range of Minnesota was begun by some of the largest steel companies in the United States.
In 1997, 45 million tons mined in Minnesota alone
Taconite is an iron-bearing, high-silica, flint-like rock. It is a Precambrian sedimentary rock referred to as a banded iron formation due to the typical alternating iron-rich layers and shale or chert layers. The very finely dispersed iron content, present as magnetite, is generally 25 to 30%. In the late 19th and early 20th centuries, iron ore was of such high quality that taconite was considered an uneconomic waste product. After World War II, most of the high grade ore in the United States had been mined out, and so taconite was turned to as a new source of iron. To process taconite, the ore is ground into a fine powder, the iron is separated from the waste rock by using strong magnets, and then the powdered iron concentrate is combined with bentonite clay and limestone as a flux and rolled into pellets about one centimeter in diameter. The pellets are heated to very high temperatures to oxidize the magnetite (Fe3O4) to hematite (Fe2O3) for further processing.
The Mesabi Iron Range region of the American state of Minnesota is a major production area. The taconite iron concentrate is shipped through Two Harbors and the Twin Ports of Duluth, Minnesota and Superior, Wisconsin, both on Lake Superior. The ore is generally shipped to other locations on the Great Lakes. Many steelmaking centers are located near Lake Erie. Originally the ore was unloaded by hand; from about 1900 through 1992, great machines called Hulett ore unloaders performed the task. Self-unloading ships made the Huletts obsolete.

13. Map of Fish Consumption Warnings (EPA)

14. Conclusion
It is important to measure the major source of mercury input to your water bodies
Fits the purpose of your network
Important contribution to your water bodies
Definitely a water concern
fish
wildlife
humans

15. here is how we operate and measure mercury…..
How Should You Monitor?
here is how we operate and measure mercury…..

16. The Mercury Deposition Network?
A 93 site sub-network of the NADP
Measuring wet deposition of mercury
Our Charge:
to determine if trends exist in wet deposition of mercury over time

17. How Do We Measure Wet?
ETI or Ott_Pluvio

18. Where We Measure Mercury
(Active Sites, May 2006)

19. Analysis Methods Cold Vapor Atomic Florescence Spectroscopy (CVAFS)
Contract Lab is Frontier Geosciences, Inc.
EPA Method 1631
reporting Limit – 0.2 ng/L
detection appr ng/L
report concentration (ng/L)
Two precipitation depth measurements
rain gage
bottle catch
report deposition (ng/m2 week)

20. Problems, Things to Remember
Very low concentrations (ng/L), so contamination is always a concern,
Mercury is volatile, so loss is possible,
Cleaning Glassware
No Teflon
Keeping lab clean
Gloves on site
Strict protocols

21. Problems, Things to Remember
Sampling difficulties
Hard to measure low concentrations
Rain bounce
Cold always a problem
Light rain events
very difficult but have the high concentrations
Good Operators are essential,
Need lots of sites
Concentration change over space
Precipitation is highly variable

22. MDN is being integrated into NWQMN
M. Brigham/USGS
Locating MDN sites on the side of water bodies of concern
Michigan (MI31), north east of Detroit
South Carolina (SC05), coastal
New Jersey (NJ30), Rutgers area
Provides him with input values, wet deposition

23. MDN integration……… M. Risch/USGS Has five MDN sites in Indiana
Along Ohio River (IN21)
Side of Lake Michigan (IN34)
Also measuring atmospheric concentrations and calculating dry deposition
Reporting total mercury deposition

24. Other Things We Measure
Methyl mercury in rainfall
methyl comes down in rain also
Trace metals in rainfall

25. QA Summary, Docs and the like
Quality Management Plan
Quality Assurance Plan
Program and lab
Blanks, Lab Blanks
Blind Tests run by USGS

26. Mercury Concentrations in Precipitation
2004

27. Mercury Wet Deposition 2004

28. Total Deposition (we need to estimate dry deposition)

29. Measurements of Dry Deposition?
Very few measurements
Very few calculations of dry deposition
BUT YOU WANT TOTAL DEPOSTION
(wet + dry)

30. Modeling Dry Deposition
Seigneur and others,
ES&T, 2004, V38,

31. Sampling box for manual system
Plans for Dry Deposition
Manually Operated Mercury Species Sampling
Monitoring station for manually-operated sampling system
EPA Method IO-5
Gold-Trap Method for Hg0 i
Sampling box for manual system

32. Automated Hg Speciation
PHg
Methods are:
-Lab Tested
-Widely used
-QA challenged
-EPA Accepted
RGM
Hg0

33. Future Directions for MDN
Monitoring Network Design Document
Where future sites should be located
Environmental Response Committee
Dry Deposition Initiative

34. Why Should We Care About
Mercury Deposition?
David Gay
Illinois State Water Survey
University of Illinois
Champaign, IL
(217)