Why Should We Care About

Mercury Deposition?David Gay

Illinois State Water SurveyUniversity of Illinois

Champaign, IL dgay@uiuc.edu (217) 244.0462

http://nadp.sws.uiuc.edu

Goal of this Presentation….

Describe the issues surrounding the mercury problem, and

Introduce you to how we operate and measure wet deposition (& dry deposition).

Why Monitor for Mercury in

Precipitation?

Issues Surrounding Mercury

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.

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: o Atmospheric Deposition – rapid and long-range

transport of certain pollutantso Groundwater flow – wide range of residence timeo Seepage from on-site waste treatment -- septic systemso Agricultural drainage -- fertilizer and manure

applications o Runoff from coastal watersheds o Riverine transport from upland watersheds –gathering

pollutants from multiple sources• others….

The mercury problem?Bioaccumulation

Bacterial action(water and sediment)

Zooplankton Small fish predatory fish

Water Body

Me-Mercury

Concentration

Dry Deposition

Wet Deposition Geologic Sources(soil, rock, base flow etc.)

Methylation

Hg Hg Hg

Through Fall(wet+dry)

Litter Fall

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)

How Mercury is Wet Deposited

Hgo

RGMHgp

Hgp

RGM

HgoHgp

RGM

rainout

washout

How Mercury is Wet Deposited

Hgo

RGM

RGM

Oxidation

Oxidation

Atmospheric Mercury Species Abundance

Hg0 – Elemental Mercury(lifetime up to 1 year)

RGM – Reactive Gaseous Mercury(lifetime hours to days)

Hgp – Particulate Bound Mercury(lifetime hours to days)

Typical Atm. Mercury Species Abundance

1.4-1.81.4-1.8ng/mng/m33

Many Mercury Sources

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

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?

Map of Fish Consumption Warnings (EPA)

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

How Should You Monitor?

here is how we operate and measure mercury…..

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

How Do We Measure Wet?

ETI or Ott_Pluvio

Where We Measure Mercury(Active Sites, May 2006)

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. 0.05 ng/L report concentration (ng/L)

Two precipitation depth measurements rain gage bottle catch report deposition (ng/m2 week)

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

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

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

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

Other Things We Measure

Methyl mercury in rainfall methyl comes down in rain also

Trace metals in rainfall

QA Summary, Docs and the like

Quality Management Plan

Quality Assurance Plan Program and lab

Blanks, Lab Blanks

Blind Tests run by USGS

Mercury Concentrations in Precipitation2004

Mercury Wet Deposition2004

Total Deposition

(we need to estimate dry deposition)

Measurements of Dry Deposition

?•Very few measurements•Very few calculations of dry deposition

•BUT YOU WANT TOTAL DEPOSTION

(wet + dry)

DRY DEPOSITION

Seigneur and others, ES&T, 2004, V38, 555-569

Modeling Dry Deposition

Sampling box for

manual system

Monitoring station for manually-operated sampling system

Plans for Dry Deposition Manually Operated Mercury Species

Sampling

EPA Method IO-5Gold-Trap Method for Hg0 i

Automated Hg Speciation

Methods are:-Lab Tested-Widely used-QA

challenged-EPA Accepted

PHg

RGM

Hg0

Future Directions for MDN

Monitoring Network Design Document Where future sites should be located Environmental Response Committee

Dry Deposition Initiative

Why Should We Care About

Mercury Deposition?David Gay

Illinois State Water SurveyUniversity of Illinois

Champaign, IL dgay@uiuc.edu (217) 244.0462

http://nadp.sws.uiuc.edu