Well Re-Appropriation Well Re-Appropriation AssessmentAssessment

City of Taneytown, MarylandCity of Taneytown, Maryland

2008 2008

BackgroundBackground

Two City supply wells developed in 2005Two City supply wells developed in 2005

Initial conservative permitted rates selected by MDEInitial conservative permitted rates selected by MDE

City operated wells at higher rates due to other well City operated wells at higher rates due to other well issues in systemissues in system

Wells performed better than expected, but MDE not Wells performed better than expected, but MDE not convinced that a higher rate is possibleconvinced that a higher rate is possible

Hydrogeologic assessment done to justify increasing the Hydrogeologic assessment done to justify increasing the permitted rate of the wellspermitted rate of the wells

AssessmentAssessment

Precipitation data over several year period reviewed to Precipitation data over several year period reviewed to determine background conditionsdetermine background conditions

Historical stream flow data reviewed to determine Historical stream flow data reviewed to determine

conditions during 2007 droughtconditions during 2007 drought

Historical groundwater observation well data reviewed to Historical groundwater observation well data reviewed to determine conditions during 2007 droughtdetermine conditions during 2007 drought

Well operational data reviewed to determine response of Well operational data reviewed to determine response of wells to the 2007 drought wells to the 2007 drought

PrecipitationPrecipitation

Monthly deviation from normal precipitationMonthly deviation from normal precipitation

PrecipitationPrecipitation

Daily precipitation used to determine levels during 2007Daily precipitation used to determine levels during 2007

Stream Flow DataStream Flow Data

Historical USGS gage data used to determine severity of Historical USGS gage data used to determine severity of 2007 drought on stream flow2007 drought on stream flow

Stream Flow DataStream Flow Data

Flow rate recurrenceFlow rate recurrence

assessed to determine assessed to determine

relative levels of 2007 relative levels of 2007

and 2002 droughts and 2002 droughts

Stream Flow DataStream Flow Data

Severity of 2007 drought impact on stream flow assessedSeverity of 2007 drought impact on stream flow assessed

Groundwater DataGroundwater Data

Historical groundwater data assessed for drought impactHistorical groundwater data assessed for drought impact

Groundwater DataGroundwater Data

2007 drought impact on groundwater levels assessed2007 drought impact on groundwater levels assessed

Operational DataOperational Data

Pumping data reviewed to assess well performance Pumping data reviewed to assess well performance during 2007 droughtduring 2007 drought

Operational DataOperational Data

Water levels reviewed to determine effect of 2007 Water levels reviewed to determine effect of 2007 droughtdrought

Well Areas of InfluenceWell Areas of Influence

Areas of influenceAreas of influence

delineated to determinedelineated to determine

potential impacts to potential impacts to

surrounding wellssurrounding wells

ConclusionConclusion

Precipitation data showed 2007 deficits similar to 2002 droughtPrecipitation data showed 2007 deficits similar to 2002 drought

2007 drought had a more severe impact to stream flow levels than 2007 drought had a more severe impact to stream flow levels than groundwater levelsgroundwater levels

Wells performed well during 2007 drought at higher rates and with a Wells performed well during 2007 drought at higher rates and with a significant cushion in drawdown levels remainingsignificant cushion in drawdown levels remaining

Wells have ability to withstand drought impacts better than expectedWells have ability to withstand drought impacts better than expected

Well capacity determination based solely on stream flow data is too Well capacity determination based solely on stream flow data is too conservative and restrictiveconservative and restrictive