County-wide Groundwater AssessmentJefferson County, West Virginia

ObjectiveAssess availability and quality of

groundwater and provide useful information toward promoting long-term management of the County’s Groundwater Resources

Groundwater Budget Study

Groundwater recharge

Groundwater usage

Maintenance of baseflow in streams

Focused on identifying the extent of the County’s groundwater resources

RechargeGroundwater originates as precipitation

The portion of precipitation that percolates downward through the soil and infiltrates into the bedrock aquifer is called Recharge:

Recharge Calculation

Recharge Area (green)

Discharge Area (red)

Previously published recharge rates were applied to County’s total recharge area to determine Annual Recharge Volume

Recharge Rates

Hydrogeologic Unit Recharge Rate (inches/year)

Recharge Area(acres)

Western 5.9 36,734

Central 5.6 70,684

Eastern 5.5 12,331

*recharge rates are representative of drought conditions

Maintenance of BaseflowUtilized published data from similar hydrogeologic setting

to estimate percentage of annual recharge contributing to baseflow

An estimated 50% of annual recharge is required to maintain baseflow in streams and is unavailable for use

Annual Recharge Estimate

Recharge from precipitation: 18,475,000,000 gallons/year

Vol. needed to maintain baseflow: - 9,237,500,000 gallons

Vol. of groundwater available for use: 9,237,500,000

gallons

Groundwater UsageConsidered the following use categories:

Public Supply

Domestic Supply

Industrial

Irrigation

Commercial

Mining

Groundwater Use Estimate

Sources of water use information:

Data Management Unit of the Engineering Division, Jefferson County Office of Environmental Health

WV Dept. of Environmental Protection, Division of Water and Waste Management

WVU Agricultural Extension Service –

Jefferson County Office 2010 U.S. Census Data

West Virginia Office of Miners’ Health, Safety and Training

Water-Use Estimates for West Virginia, Atkins, 2004 – USGS publication

1,465,250,000 gallons per year

Groundwater Use EstimatePercentage of available groundwater used annually:

1.47 bgy 9.24 bgy

Groundwater use estimate:Groundwater deemed available: 16%

Groundwater Well DatabaseAssistance provided by the

Jefferson County GIS Department

Utilized available well completion reports from Health Department

Database consists of over 1100 wells with georeferenced locations

Internship

• Worked for Jefferson County GIS/Addressing Office

• Water budget study• Analytical Services Inc.

The Effect of Bedrock Geology on Well Yield in Jefferson County, West Virginia

Jeremiah SandersShepherd University

My Study

• Focus on geology• How geology affect well yield• Null Hypothesis: There is no difference in the

distribution of well yield between the bedrock formations

Methods

• Well database• Clean up

database• Create parcel ID

Methods

• Importing to ArcGIS• 1276 parcel match• Quality assessment

Methods

• Create new database• New field entries• Examined well

completion reports• Inconsistent entries

in well completion reports

Methods

• Join new database to parcels/address Points

• 911 well points

Methods

• State well records and USGS study (McCoy et al. 2005)

wells added• Total 1124 well points• Joined bedrock data to

well points• Used SPSS 19(IBM, USA)

to check for normality and K-W test

Results

Єa Єe Єh Єt Єw Єwl OЄc Om Omu Opr Os Zc0

50

100

150

200

250

300

Bedrock Formation

# of

Wel

ls

(Єa)-Antietam Formation

(Єe)- Elbrook Formation

(Єh)-Harpers Formation

(Єt)-Tomstown Formation

(Єw)-Waynesboro Formation

(Єwl)-Weverton and Loudoun Formations undivided

(OЄc)- Conococheague Limestone

(Om)-Martinsburg Formation

(Omu)-Middle Ordivician limestone

(Opr)-Pinesburg Station Dolomite and Rockdale Run Formation

(Os)- Stonehenge Limestone

(Zc)-Catoctin Formation

Results

Єa Єe Єh Єt Єw Єwl OЄc Om Omu Opr Os Zc0

20

40

60

80

100

120

140

160

180

Bedrock Formation

Aver

age

Yiel

d (lp

m)

(Єa)-Antietam Formation

(Єe)- Elbrook Formation

(Єh)-Harpers Formation

(Єt)-Tomstown Formation

(Єw)-Waynesboro Formation

(Єwl)-Weverton and Loudoun Formations undivided

(OЄc)- Conococheague Limestone

(Om)-Martinsburg Formation

(Omu)-Middle Ordivician limestone

(Opr)-Pinesburg Station Dolomite and Rockdale Run Formation

(Os)- Stonehenge Limestone

(Zc)-Catoctin Formation

Hydrogeologic UnitsAreas possessing unique characteristics

Western Fault Dominated

Central Folded Carbonates

Eastern Metamorphics

Table of Mean Values

Review of well database illustrates uniqueness of each Hydrogeologic Unit:

Hydrogeologic Unit

Well Depth(feet)

Yield(gpm)

Depth to Water(feet)

Casing Length

(feet)

Western 281 19 46 57

Central 278 32 66 74

Eastern 355 14 94 83

Groundwater Development PotentialThe Central Unit has the greatest number of high yielding wells

Yield (gpm)

Hydrogeologic Conditions Vary Across County

Site-specific assessment is recommended to understand compatibility of groundwater development with planned use

Water Quality Review

Common Groundwater Contaminants:

Hydrogeologic Unit

Common Contaminants

Western Sulfate, Nitrate, Bacteria, Hardness

Central Nitrate, Bacteria, Hardness

Eastern Iron, Manganese, Radionuclides

Contaminant MigrationInfluenced by geologic conditions and land use

Conduits in Karst areas can facilitate direct groundwater contamination and rapid contaminant transport

RecommendationsTo promote sustainability and long-term protection of the County’s groundwater resources, ASI recommends:

Assessment of High-Yield withdrawals

Incorporating Groundwater Protection into long-term planning