Salt in Dutchess Co. Waters Stuart Findlay

Vicky Kelly

Where are we now?

Compared to what?

Where are we headed?

Should we be worried?

Acknowledgements• Fishkill Creek Watershed Comm. (R. Oestrike)

• Environmental Management Council (D. Burns, C. Klocker)

• Hudson River NERR (W.C. Nieder, S. Ciparis)

• Town of Clinton CAC (N. Coller)

• Vassar College (K. Menking et al.)

• Syracuse U. (D. Siegel, L. Jin)

• WRI – Cornell; COE - Syracuse

Some Chloride Reference Points• Background - ~ 10 mg/L or less [Catskill Reservoirs]• Sublethal – 50-100 mg/L Subtle yet Significant

– Biotic Indices– Microbial processes– Associations

• EPA Chronic – 230 mg/L• Drinking Water Std – 250 mg/L• EPA Acute – 860 mg/L• Lethal - 1000 or higher

SIMPLER

• REFERENCE <10 mg/L

• ENVIRONMENTAL EFFECTS ~ 100 mg/L

• LETHAL > 1000 mg/L

DUTCHESS COUNTY WATERS80 mg/L (+/- 79 SD)

Mullaney et al., USGS

DC

Ten Mile10-40

Crum Elbow15-50

Casperkill100-300

Chloride(mg/L)

Wappinger10-45

Fishkill10-100

WAPPINGER CREEK JULY 2006

20

30

40

50

0 5 10 15 20 25 30 35 40

Downstream Increases

DISTANCE FROM MOUTH (km)0 5 10 15 20 25 30 35

Chl

orid

e (m

g/L)

0

20

40

60

80

100

120

140

160

FISHKILL CREEKSummer 2005

Popula

tion

Residential Land Cover and Chloride (M. Essery)

Subwatersheds in the Fishklill Basin

High concentrations in summer

0

20

40

1 2 3 4 5 6 7 8 9 10 11 12

MONTH

CH

LOR

IDE

(mg/

L)

East Branch Wappinger Creek, Millbrook

No decline in summer concentrations

Long-term increases in concentrationEast Branch of the Wappinger Creek

Kelly et al. ES&T 2008

Cl (mg/)

0

10

20

30

40

50

1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009

Saw Kill Creek

HRNERR

• Low-density residential

• Yearly mean Cl-

concentrations have doubled since 1991 (20 to 40 mg/L)

• Similar Cl- concentrations throughout year

Year1990 1992 1994 1996 1998 2000 2002 2004

Chl

orid

e (m

g/L)

0

10

20

30

40

50

60

All Patterns Suggest a Reservoir

• Soil Sorption or Groundwater?

STREAM

• Road salt biggest source – others?

SOIL CORES HOLD Cl LONGER THAN WATER

Kincaid and Findlay, 2009

Groundwater ?

05

1015202530354045

25 50 75 100 125 150 175 200 225 More

Chloride (mg/L)

% o

f Sam

ples

WELL

SURF

Fig. 4: Frequency distribution of chloride concentrations in surface and well samples from Dutchess County.

A few wells have Cl > surface water concentration – Could support high baseflow concentrations

Private drinking-water wellsNon-random but widely distributed

CHLORIDE IS NOT ALONE

0 30 60 90 120 150 180 210

CL (mg/L)

0

4

8

12

16

20

24

NO

3 (m

g/L)

D. Burns - EMC

Should we be Worried?

• At the brink, trends are not encouraging

• Groundwater concentrations must be increasing

• What else is coming along?

Scope for Action

• Reduced Salt is in Everyone’s Interest

• Widespread Problem, Lots of Mental Horsepower

• Solutions may Require Capital

What do we Need to Know?Today’s Program

• Environmental Effects – Not Huge Yet but Close?

• Human Health Effects

• Cost – Direct (Salt is cheap, labor is not, use is high)– Indirect (Corrosion, contamination

• Solution?