Marcellus Shale-Gas Development 

and Water-Resource Issues 

John Williams

New York Water Science Center 
Tompkins County, NY

High TOC and 

elevated radioactivity

in basal Marcellus Shale

Levanthal and others (1981)
Uranium & Thorium to Radium & Radon 

Radioactive Decay Series

Radioisotope and half life
Drill Core Sample Analysis

Lash and Engelder (2009)

Gamma Log

High TOC and abundant pyrite in basal Marcellus Shale
Teff (2011)

Horizontal wells target basal Marcellus Shale 
Directional rig for drilling 

horizontal leg

Top-set rig for drilling vertical 

surface-cased interval
Walking legs on 

directional drilling rig 

Wellheads of first two of six 

horizontal wells 

~15 ft
Target horizon (Union Springs Shale) mapped 

using offset well logs and seismic

Logging-while-drilling used to steer lateral 

within target beds

Schlumberger (2010)

Gamma

Density
• Elevated uranium and abundant pyrite in high-TOC black shale 

• Multi-horizontal well site will generate more than 500 times the volume

of shale cuttings than single-vertical well site 

Drill Cuttings

Core of target interval Drill cuttings
Lined pit 

Mixed with sawdust 

Closed-loop system 

Offsite disposal in landfill

Drilling Fluids and Cuttings
Papso and others (2010)

Blauch (2010)

Contains elevated TDS, chlorides, 

barium, and radioisotopes whose 

concentrations increase 

during the flowback period 

approaching formation brine 

Flowback
Chloride (mg/L)

0

20,000

40,000

60,000

80,000

100,000

120,000

1 2 3

Total dissolved solids (mg/L)

0

50,000

100,000

150,000

200,000

250,000

1 2 3

Gross Alpha (pCi/L)

0

5000

10000

15000

20000

1 2 3

Barium (mg/L)

0

2500

5000

7500

10000

1 2 3

Water quality of flowback (1.5 million gallons) from Marcellus shale well after completion of hydraulic 

fracturing (Samples were taken at 1, 2, and 3 third intervals of the 2-week flowback period, PADEP)

1,160

22

19,000

668

6,100

8,730

18,600

80,500

109,000

34,600

134,000

192,000
Uranium & Thorium to Radium & Radon 

Radioactive Decay Series

Radioisotope and half life

Brine from a Marcellus Shale-Gas Well

Gross Alpha 20,800 pCi/L

Gross Beta 2,390 pCi/L

Radium 226 10,200 pCi/L

Radium 228 1,250 pCi/L

Thorium 228 47.5 pCi/L 

Thorium 232 0.0 pCi/L

Uranium 234 0.5 pCi/L
Reuse of frac water, onsite treatment for 

solids / blend with 70 % freshwater 

Municipal wastewater treatment 

plants not designed to handle 

flowback chemistry 
Halliburton (2010)

Microseismic Mapped Frac Tops and Bottoms

Marcellus Shale
Trenton

Salt

Marcellus

Utica

Lockport

Onondaga

Smith and Leone (2010)

Structure (folds and faults) 

Seismic survey 
250

600 223

3.8

0.18

1.12

0.0008

0.011 14

7

Water quality of water well impacted by Medina gas drilling
Methane in Water Wells 

Marcellus/Utica Gas-Play Area

Osborn and others (2011)

Sampling sites
FRESH WATER AQUIFER ZONE

SHALLOW PRODUCING ZONE

INTERMEDIATE PRODUCING ZONE

CONDUCTOR PIPE

SURFACE CASING

PRODUCTION CASING

Good Zonal Isolation

TARGET PRODUCING ZONE
Poor Zonal Isolation

PRESSURE 

BUILDS UP

CONDUCTOR PIPE

SURFACE CASING

PRODUCTION CASING

FRESH WATER AQUIFER ZONE

SHALLOW PRODUCING ZONE

INTERMEDIATE PRODUCING ZONE

TARGET PRODUCING ZONE

CASING

CEMENT

FORMATION
Fractured Zones in Upper Devonian Bedrock

Pathways for methane and brine migration
2,500 – 4,000 feet

Characterization of deep freshwater

and shallow gas and saltwater 

Engineered zonal isolation by

casing, cement, packers, and venting 

Protection of Freshwater Aquifer
Freshwater 

Transition 

Saltwater 

Geophysical Logs and Base of Freshwater Aquifer