-Road Salt In The Lake George Basin- A Long-term Watershed Case Study

& Current Basin-wide Research

http://www.wildernessphotographs.com/photo.php?id=1056

Why is the focus on road salt in the Lake George drainage basin important?

▪ There has been a 3-fold increase in the concentration of NA+ and CL- in Lake George during the past 30 years

▪ Winter highway deicing practices are the primary source of these compounds

▪ Direct correlation between the surface area of watershed roads and [Cl-] of the stream draining the watershed (Swinton et al 2015)

The State of the Lake: Thirty Years of Water Quality Monitoring on Lake George. Lake George, New York, 1980 – 2009. (Boylen et al 2014)

Volume-weighted annual concentration of chloride in wet precipitation at Huntington Forest, NY (from NADP (2016) http://nadp.sws.uiuc.edu/data/ntn/plots/ntntrends.html?siteID=NY20)

2009 mean annual [Cl-] in Lake George was >350xs the volume-weighted [Cl-] in wetfall

-Long-term Watershed Case Study-

Finkle Brook Watershed

▪ Located on the west side of Lake

George (Town of Bolton) ▪ 7th largest watershed in the Lake

George drainage basin

Finkle Brook Watershed Case Study

▪ Surface area = 4.2 mi2

▪ Length of channel = 4.65 mi

▪ Mean basin slope = 903 ft/mi

▪ Mean annual ppt = 37 inches

▪ Mean annual runoff = 18 inches

Finkle Brook Watershed Case Study

▪ Began studying Finkle Brook and watershed in 1992

▪ Instrumented channel near outflow for continuous flow and automatic sample collection

▪ Collected base-flow and storm event samples for chemistry

▪ 1992-2005 – monitored 89 storm events and collected numerous base-flow chemistry samples

-Historical Information- Lake George Urban Runoff Study

▪ 3 Year Study (1980-1982) ▪ US EPA Nationwide Study (28 sites) ▪ South end of Lake George ▪ 7 Stream/Stormsewer Stations ▪ Direct drainage along shoreline ▪ 40+ Storm Events Sampled

-Historical Information- Lake George Urban Runoff Study

There is a direct relationship between areal loading and percent development

-Winter Road Maintenance- Lake George Drainage Basin

In the beginning (1960s-1970s), the primary winter de-icing compound was sand…..

…..and this was the result

By 2002, the volume of the Finkle Brook delta was

estimated to be >13,000 yd3

Finkle Brook Watershed Case Study Sources of Data

Fuhs - NYSDOH (1972)

LGUR Study- NYSDEC (1980-82)

Sutherland - NYSDEC (1991-2006)

Swinton - DFWI (2007-2010)

Sutherland and Navitsky (2013-16)

Finkle Brook Watershed Case Study Long-term Increase in Base-flow [Chloride]

Flow-weighted Base-flow [Cl-] at Outlet since 1970 Baseflow [Cl-] - Source & Outflow

R² = 0.7649

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20

40

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1970 1975 1980 1985 1990 1995 2000 2005 2010 2015

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mg/

L

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0.72

106.62

22.0

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1000.0

EDGECOMB POND(above)

FINKLE AT OUTFLOW(below)

FUHS AT OUTFLOW(1970-71)

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mg/

L Sampling Station

Finkle Brook Watershed Case Study The Finkle Brook Corridor - Edgecomb Pond to Sawmill Bay

▪ DELINEATED 1,000-FT CORRIDOR FROM EDGECOMB POND TO SAWMILL BAY

▪ LENGTH OF CORRIDOR FROM POND TO SAWMILL BAY IS ~12,000 FEET

▪ SURFACE AREA OF CORRIDOR (EXCLUSIVE OF CHANNEL) = 260 ACRES

▪ ROADS WITHIN CORRIDOR = 15.5 ACRES, OR ~6 PERCENT OF TOTAL CORRIDOR AREA

Summary of Finkle Brook Watershed Case Study

▪ Roads adjacent to FB corridor are having an impact (sediment/nutrients) on the water quality of Finkle Brook and, ultimately, Lake George

▪ Sedimentation basins placed strategically along stream corridor will reduce the impact of sediment and adsorbed contaminants

▪ However, salt reduction only can occur through strict adherence to BMPs such as The S.A.V.E. Lake George Partnership

Current Basin-wide Research

▪ During the winter of 2015-2016, a greatly reduced snowpack and reduced application of road deicing material provided the opportunity to study the response of streams and their watersheds to these reductions

▪ Currently studying 14 watersheds; all 14 streams are sampled for [anions:cations] prior to flowing into Lake George; 11 streams also sampled above the developed area to provide base-flow [anions:cations]

▪ The FUND For Lake George is sponsoring this study

Finkle Brook - 2016

▪ Fuhs (1972) dataset most robust for meaningful statistics

▪ Sutherland (2001) data above Fuhs regressions, with S&N 2016 well above 2001 data for flow equivalent conditions

▪ 2016 base-flow (<2 cfs) [Cl-], [Na+] and [Ca+] are increasing

Current Basin-wide Research

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meq

/L

flow, ft3/sec

meq Cl/L (Fuhs 1972)

meq Na/L (Fuhs 1972)

meq Ca/L (Fuhs 1972)

meq Cl/L (Sutherland 2001)

meq Ca/L (Sutherland 2001)

meq Cl/L (S&N 2016)

meq Na/L (S&N 2016)

meq Ca/L (S&N 2016)

THE FUTURE OF ROAD SALT IN THE LAKE GEORGE BASIN

• REDUCE THE USE • JOIN THE S.A.V.E. LAKE GEORGE PARTNERSHIP