DE Envirothon Aquatics DE Envirothon Aquatics Training:Training:

Groundwater – Surface WaterGroundwater – Surface WaterConnectionConnection

Chris Brown, HydrologistChris Brown, Hydrologist

Delaware DNRECDelaware DNREC

Tank Management SectionTank Management Section

Key Online ResourcesKey Online ResourcesGroundwater & Surface WaterGroundwater & Surface Water

USGS – USGS – www.usgs.gov/education - - USGS Circular 1139 “Groundwater and Surface USGS Circular 1139 “Groundwater and Surface

Water”Water” USGS – “Groundwater & the Rural Homeowner”USGS – “Groundwater & the Rural Homeowner” DE GS – DE GS – www.dgs.udel.edu

Water Resources & Water Conditions tabsWater Resources & Water Conditions tabs DE Environmental Observing System – DE Environmental Observing System –

www.deos.udel.edu “DEOS Geobrowser “DEOS Geobrowser National Estuarine Research Reserve System -National Estuarine Research Reserve System - http://nerrs.noaa.gov – Research & Monitoring data – Research & Monitoring data

CDMO – Get Data – Data ExportCDMO – Get Data – Data Export Google Earth & Air PhotosGoogle Earth & Air Photos

At an Eco-Station, consider the At an Eco-Station, consider the following:following:

Where is the water & where is it going?Where is the water & where is it going? How does the water fit into the eco-system? How does the water fit into the eco-system? ““Read the land” - what does the topography tell Read the land” - what does the topography tell

you?you? Be ready to interpret air photos, topo maps, or sets Be ready to interpret air photos, topo maps, or sets

of water quality data (surface or groundwater) of water quality data (surface or groundwater) What may influence the flow of the water?What may influence the flow of the water? What may affect the water quality, and key What may affect the water quality, and key

parameters (D.O., temperature, etc.)parameters (D.O., temperature, etc.) How have (or could) humans affect the water How have (or could) humans affect the water

quality?quality?

Part of the Hydrologic Part of the Hydrologic CycleCycle

AquiferAquifer

Geologic formation, either sediment Geologic formation, either sediment or rock, capable of bearing water or rock, capable of bearing water and supplying water to wellsand supplying water to wells

Coastal Plain aquifers consist of Coastal Plain aquifers consist of sedimentsediment

Piedmont aquifers are generally Piedmont aquifers are generally bedrockbedrock

Groundwater Flow: Where? And How Groundwater Flow: Where? And How Fast?Fast?

PorosityPorosity Void spaces within Void spaces within

sediment or rocksediment or rock Between sediment Between sediment

grainsgrains Fractures in rockFractures in rock InterconnectedInterconnected

PermeabilityPermeability Hydraulic Hydraulic

ConductivityConductivity Ability of material Ability of material

to transmit a fluidto transmit a fluid Sand & Gravel – Sand & Gravel –

HighHigh Clay - LowClay - Low

Groundwater Flow: Why and Where?Groundwater Flow: Why and Where?

From high to low elevation – even a From high to low elevation – even a few inchesfew inches

From high to low pressure – pumping From high to low pressure – pumping wellswells

In humid regions, like the mid-In humid regions, like the mid-Atlantic, flow is generally toward a Atlantic, flow is generally toward a surface water bodysurface water body

Wells and recharge will influence flowWells and recharge will influence flow

Common Scenarios in Delaware:Surface & Groundwater Connection

Groundwater seepage along Indian River Bay

Areas free of ice that result from warm ground water (15 degrees C) discharging into cold surface water (5 degrees C) in the Inland Bays

WELLS

Vadose Zone

Water Table

Screen

Sand Pack

TYPICAL WELL

Pump

GENERALIZED GEOLOGIC GENERALIZED GEOLOGIC CROSS SECTION OF KENT CROSS SECTION OF KENT

COUNTYCOUNTYMILFORDMILFORD

FELTONFELTONWOODSIDEWOODSIDE

DOVERDOVERCHESWOLDCHESWOLDCLAYTONCLAYTON Columbia AquiferColumbia Aquifer

+50+50

-100-100

-200-200

-300-300

-400-400

-500-500

-600-600

-800-800

-700-700

-900-900

Frederica Aquifer

Rancocas Fm.

CheswoldAquifer

Piney PointAquifer

TD=276'TD=276'

TD=1168'TD=1168'

-1000-1000

TD=606'TD=606' TD=611'TD=611' TD=626'TD=626'

TD=955'TD=955'

Columbia AquiferColumbia Aquifer

Columbia Aquifer

Soil Layer

•Most susceptible to contaminationMost susceptible to contamination•Most adversely affectedMost adversely affected

•Most heavily used aquiferMost heavily used aquifer•IrrigationIrrigation•Public water supplyPublic water supply•Domestic water supplyDomestic water supply•75% of stream flow75% of stream flow

Delaware Geological Survey

Making the ConnectionMaking the Connection

Remember the Remember the groundwater-groundwater-surface water surface water connectionconnection

and the and the GROUND GROUND SURFACE -SURFACE -groundwater groundwater connection…connection…

Part of the Hydrologic Part of the Hydrologic CycleCycle