bull bull 7 LampOIIOYampLbullbullT-IT 00 -L- TOfilt CTT0 17

0187-EPA-884

Contract No 68-WS-0117

January 14 1991

Mr Robert Leger US Environmental Protection Agency J F kennedy Federal Building Boston Mauachueetts 02203

Subject 1 Groundwater Model Groveland Wells Site Supplemental - RIPS W A I 04-1L32

Dear Mr Leger 1

This letter is eutitted in reaponee to your facaibullUe received on Decebullber 26 1990 concerning the Groveland coaputer 1104el effort In addition the attachltent providebull the following utertl for discussion at the upcoaing IIOdeling bulleeting

l sury of annuallymiddot averaged TCE and l 2-DCE concentrationbull in the study area

2 SuMary of ltreabull Aquifer Interactionbull in Plowpath IIedel Calibration and Validation Runa

3 Echoprinte of the Plowp~th Model Calibration and Validation Runs

4 Calculation of Plowpath Model Reeidual Brrora

s Distribution Map of Plovpath Model Reaidual Errors (no pWiping PUJIP teat and dravdovn)

6 Plovpath Model Outputs of Sibullulated Scenarios (Hydraulic Bead Velocity Pathlinee and Capture Zones)

Mapa (11 x 17)

bull Bott011 of Aquifer Mlp b Hydraulic Condictivity Map c Conaunt Bead Conditione Map d Surface Wbullter Conditions Mbullp e Surface Water Interactions Map f Surface Recharge Arebullbull Map

Mr Robert Leger January 14 1991 Page Two

Bel ow are the responses t o your facs i mile

Item 1 Provide written summary of meeting on December 20 1990

Response A written summary of the meeting is attached

Item 2 Provide maps (all at same scale) showing the following hydraulic conductivity distribution recharge distribution stratified dr i ft and till at land surface bottom of aquifer (where bedrock or till) and stream modes

Response See attachment to this letter

J Item 3 Provide Nip figures showing the diatribution and

ugnitude of residual water levela for the following aiaulations measured ( l-16-90) non-pumping conditions va final calibration valuea aeaaure (3shy90) pubullping conditions va dmulated valuea

Response See attactent to this letter

Item 41 Discuss criteriA for satilfactory calibration of IIOdel

Reaponae In general the criteria for a satilfactory groundwater flow MOdel calibration ia that the ditterencea between model calculated and field aaured water elevationa (residual errore) be within ita range of noraal seasonal changes in the 11odeled area As ahown in the atUched table the atandard deviation between 12 2189 and l 0690 field aeaaureaenta ia 2 49 feet while two model runa have 2 06 and 188 feet residual errors for the no-pumping and pu11ping acenarios respectively Clearly the llodeling reaulta IIAtch the field meaaurementa in both caaes better than the agreement between two sets of field measurements under natural condi tiona Therefore the model calibration was deterrained satisfactory

NUS CORPORATION

Mr Robert Leger January 14 1991 Page Three

Item 5 Simulate other pump tests Sta No 1 - when first constructed - 1987 Sta No 2 -when constructed (if not possible or should not be modeled explain why)

Response No accurate pumping rate was available for all three cases listed Although the water elevations in 6 monitoring wells are available for the 1987 pumping teat it will not be meaningful to com~re model outputs to measured water elevations with an aaaumed pumping rate

Item 6 Provide water balance data for all aimuhted (items 3 and 5) Com~re discharge measurements with Isimulations for 87 and 90 pump tests

Reaponae 1 The Plow~th Model does not provide an internal Naashy ~~ balance check It is very time conaumin9 to check the uaa balance in detail aanually because every surface water and constant head blocks t09ether with all the blocka with surface infiltration need to be conlidered in the cAlculation one by one However the aha of liaulated capture aonea and the surface infiltration ratea in the zones were used to calculated the water supply available to puaping Ita No 1 (andor 2) for each puaping scenario simulated By coaparing the puaping rates uaed and the water supply available no obvious aaaa-~lance error has been found

Item 7 Check preacr ipt ion recorda for cloaeat weather aUtiona and use those data

Reaponae The local (Haverhill Wastewater Treataent Plant) precipitation recorda have been obtained They can be used ta select initial possible infiltration ratea which need not to be very accurate Since there are ao aany factors that can affect the actual infiltration rate in each area the final infiltration rates can only be determined through the flow model calibration

One other use of the local precipitation records ia to check whether the hypothetical conditions used in s ome of the scenarios ( i e Tests 1 through Test 6) can actually exist during the 1970s or not

NUS CORPORATION

~ Mr Robert Leger January 14 1991 Page Four

Item B Oeser ibe recharge estimate technique

Response The Hydrologic Evaluation of Landfill Performance (HELP) model was used to estimate the possible surface infiltration rates for the study area A 10shyfeet soil column representin9 the a verage thickness of the vadose zone with different types of surface coverage and hydraulic conductivity were used in simulation of the water bud9et balance The local climatological data was used when possible

As mentioned earlier these estimates need not to be very accurate because the final values and distribution of the infiltration rates were determined by the flow model calibration process

tea 9 Discuss hydrologic conditions to be aiaulated for long term transport IIOCeling How will estiutes of groundwater discharge (base flow in streallls) be made

Response Hydrolocaic conditions for long termmiddot simulations usually should be the site specific long term averaged conditiona But according to the IIOdeling results of some simulated hypothetical conditions we uy like to simulate some extre11e conditions too

Item 10 Discuss what the physical basis for the two h1yer 11odiel will be Are two layen sufficient

Response These queations can be better answered when the 3-D model results are available At this ti11e it is believed that the groundwater flow PAttern in the bedrock and till is in general the same as the flow in the overburden and a two-layer model will be sufficient for the study The interaction betweeen the two model layers needs to be considered in detail during the development of the 3-D model

Item 11 How will you justify the selection of the aquifer bottOIIl as proposed What are the consequences of this selection in light of contamination in bedrock and till

NUS COAPOAATION

Mr Robert Leqer January 14 1991 Pa9e Fi ve

Response The top of bedrock was selected as the bottom of the aquifer because the hydraulic conduct i vity of the bedrock is two orders of magnatude lower than the atratified drift Therefore the bedrock flow is minor when compared to overburden flow The hydraulic conductivity inputvalue of 90 ft day for the s tratified drift as derived from the pumpin9 teat reflects leaka9e from the bedrock

Item 12 Diacuaa rational for assigning atreambed properties Show stream bullodes of 9ain or loaa

Reaponae The locationbull and propertiea of atreaampD blocka are au11111111rhed in the attached table Water aurface elevationbull were aaaigned bAaed on the atatf gauge Maaureaenta alon9 the creek and were aet a a conatanu in the aodel The leaka9e factorbull were eatited by uein9 vertical hydraulic conductivitiea and ahea of the aurface area of the atre in each block Streaa-aquifer interactionbull depend on the) differencebull between the aiaulated groundwater elevationbull and aurtace water elevationbull aaaigned at theae blocka When the 9roundwater elevation ia higher the atreaa ia 9ainin9 otherwiae the at ream ia rechargin9 the aquifer Therefore the direction of water flow will be decided autOIUitically by the adel when aiaulating different puaping acenarioa A up ahowin9 the locationa of 9aining and loling aectiona of the creek for the IDOdel calibration and validation reaulta is provided

Item 13 Show reaulta and discuSI trans ient 1i11ulationa of puap teata (pa and 9roundwater level hydrographa)

Responae Plowpath only dbullulatea ateady-atate flow condit i ona Therefore the pumping teat waa approxiuted aa a ateady-atate puaping acenar io No hydrograph ia available at thi a time

NUS CORPORATION

Mr Robert Leger January 14 1991 Page Six

Additional explanation if necessary can be provided at our meeting

PMO-~ JRPaptd

Bncloaurea

CCI D Kelley (IPA) D Willey (IPA) wenc J tleparatek (DD) venc G Gerdner (IIUS) JD ChlouJ Orient (IIUS) rue 0216-0lOO

NUS CORPORATION

Meeting Summary

CCputer Modeling Groveland Wells Site

Supplemental MOM RIFS

Date December 20 1990 Place US EPA 90 Canal St

Boston Maaaachuaetta Project Supplemental MOM RIFS EPA W A No 04-lL32 NUS Project No 0216 Prepared by J Forrelli NUS Corporation

Attendeea r

PAr Robert Leger Remedial Project Mana9er (RPM) Richard Willey BydrOCJeOlOC)iat David Zeni ARCS I Contract Officer

USGS 1 Wayne Lathu

Maaaachuaetts DIP Jay ~paratek

HOI Corporation (IPA Contractor - ARCS I Progr) r J D Chiou Civil Zn9ineerModelin9 Specialiat Jeff Orient BydrOC)eOlOCJiat A Otrofaky Deputy Pr09r Mana9er Ja R rorralli Project Mana9er

Pureoser

Thh bulleting waa held at the requeat of IPA to diacuas the input conditione for the groundwater aodel under develos-ent by NUS in accordance with the work plan uendllent dated Deceaber 1990 (Qnly one meeting waa projected in the work plan - at 75 CCIIpletion Other additional aeetin9s may also be middot held during the adel development proceas

Diacusaion r

A table aUJUUrhing alta groundwater TCE levela annually for each well for the period 1910 through 1990 wa1 presented The table wa1 ~1ed on historical data bulls well as the current Supplementbull RI re1u1ts Re1ulta for wells allllpled aore thbulln once ln a year were 1veraged Selected d1t1 will be used for model calibration and validation

-l shy

-_ It waa agreed that OCE will not be modeled althouqh OCE could be modeled independently TCE and OCE have different densities and decay rates and can bull t be modeled as a total mass A aecond data table for OCE will be prepared

Sufficient data for transport model calibrationvalidation exiata The calibration and validation process waa discussed The model will be con1tructed on the bash of the 1983 TCE data set calibrated udng 1984 TCE data set and validated with the 1984-90 TCE data aets

The tran1port model interpolates actual values to determine TCE

I I

leveh between data pointbull vertically and horizontally

Changea in TCE levela re1ult from dilperlion and decay Total 1aa11 of TCE in the aodel will reuin conatant becau1e no decay will be lillulated

Sea1onal differencebull wouldnt be accounted for with thh llodel Model inputoutput h aeauaed for a eteady bulltate condition with c011pariaona aade on a annual inatead of aea1onal bJaia ~~ The llodel area 11 lar9er than the area IIOdeled by ERT Exhibita of thbull aodel 9rid bott011 of aquifer and infiltration rate eatiaatea were preeentect Boundary conditionbull and IIOdel reaolution were diiCUIIed

aeaulta of-the are recent Cheaterton anitoring will be included in the cheaical data bale

A printout of reaidual hydraulic heada will be aupplied to EPA with the adel re1ulta

Eatiaatea of detailed aaaa flux are very difficult becauae of the aurface watergroundwater interaction

Preliainary tlovpath adel re1ulta conahting of exhibitbull depicting hydraulic head contoura and groundwater flow velocity were pre1ented for the following acenarioa

1 No pullpin9 2 1990 puaping teet 3 Sta No 1 at 600 9pm Sta No 2 at 500 9pm 4 Sta No 1 at 600 9pm 5 Sta No 2 at 500 gpm

The next meeting waa tentatively aet for January 11 1991

The aeeting adjourned at approximately 330 pa

-2shy

UNITED STATES EN VIRONMENTAL PROTECTI ON AGENC Y REGION I

JFK Federa l Build1ng Boston MA 02203-2211

MEMORANDUM

DATE Deceoer 24 1910

SUBJ ~~ mer 1c e l ground-water ~oae i 1ng Grovela-o ~we ll s S1te Gr ove l an e t-14

FROM

TO

i rgte llicmiddot ~ltln t~ 11 st )f 1te ns reel to te aao~esec cy t1U~ - IF t nerc ar~ tny oestlcns t e J s l I O OE- r e e reO to ltayne ~acr al

vSG S f middot~1i - 5t5-t - ~

f ffVU I C c~ rgt-ec t ~ a t 11 i l st coe rlt S l gra l C S S~-middotsatmiddotmiddot )r

wmiddot~n N Lmiddot ~ middot s e~torts to oa t e r a umiddoter u-at we war t t he to oroouce a gJl J aef ens 1 o middotmiddot t~ mcmiddotoel

Q 1bull J- - o v oe wn t te~ SLa r y ot mae t g

1 i=lno v cbull maos 1al l a t sane s c a l e S 10middot~ 1 ng e +c ICmiddotI-111

nvomiddotmiddot a ~-bulll c co ~1 ou middot t1 1 1ty Ol StlOut on re~narce middotJI~tr ll 1 1 bull stat1f 1e c dnft anl t 1 l i at hr~ surfac e on t toM o f ao w1 f e r I where oecroc~ c t 1 I middot

s t rearr noles

l lr Ol de lap f middot g or e ~ 3ncw1r1g t t e d l StrlOJt l c n aro Tla 3 1 tl~~

of reslOJal water middotlE-ve ls for t ne following simu lati o s

measuPec I 3 - 16-9(bull l nor- oumoi ng cona i t 1ons vs t tnal calibrat 1o n va lues

measured I 3-90) p umo1ng conditton vs s 1mulatea values

4 1 Dtscuss cnter1a f o r sat 1sfac t o q ca l 1orat l On o f moo~ l

5) Simulate other oumo t ests

St a 0 - nemiddot bull 1 St COS~ru t e J

- 1~17

~ ta tmiddoton - ~lto r e ~ c c l t middotJ c t e J

s hou i o not oe modelec e xo 1a 1n wn y t

Mr Robert Leger January 14 1991 Page Two

Bel ow are the responses t o your facs i mile

Item 1 Provide written summary of meeting on December 20 1990

Response A written summary of the meeting is attached

Item 2 Provide maps (all at same scale) showing the following hydraulic conductivity distribution recharge distribution stratified dr i ft and till at land surface bottom of aquifer (where bedrock or till) and stream modes

Response See attachment to this letter

J Item 3 Provide Nip figures showing the diatribution and

ugnitude of residual water levela for the following aiaulations measured ( l-16-90) non-pumping conditions va final calibration valuea aeaaure (3shy90) pubullping conditions va dmulated valuea

Response See attactent to this letter

Item 41 Discuss criteriA for satilfactory calibration of IIOdel

Reaponae In general the criteria for a satilfactory groundwater flow MOdel calibration ia that the ditterencea between model calculated and field aaured water elevationa (residual errore) be within ita range of noraal seasonal changes in the 11odeled area As ahown in the atUched table the atandard deviation between 12 2189 and l 0690 field aeaaureaenta ia 2 49 feet while two model runa have 2 06 and 188 feet residual errors for the no-pumping and pu11ping acenarios respectively Clearly the llodeling reaulta IIAtch the field meaaurementa in both caaes better than the agreement between two sets of field measurements under natural condi tiona Therefore the model calibration was deterrained satisfactory

NUS CORPORATION

Mr Robert Leger January 14 1991 Page Three

Item 5 Simulate other pump tests Sta No 1 - when first constructed - 1987 Sta No 2 -when constructed (if not possible or should not be modeled explain why)

Response No accurate pumping rate was available for all three cases listed Although the water elevations in 6 monitoring wells are available for the 1987 pumping teat it will not be meaningful to com~re model outputs to measured water elevations with an aaaumed pumping rate

Item 6 Provide water balance data for all aimuhted (items 3 and 5) Com~re discharge measurements with Isimulations for 87 and 90 pump tests

Reaponae 1 The Plow~th Model does not provide an internal Naashy ~~ balance check It is very time conaumin9 to check the uaa balance in detail aanually because every surface water and constant head blocks t09ether with all the blocka with surface infiltration need to be conlidered in the cAlculation one by one However the aha of liaulated capture aonea and the surface infiltration ratea in the zones were used to calculated the water supply available to puaping Ita No 1 (andor 2) for each puaping scenario simulated By coaparing the puaping rates uaed and the water supply available no obvious aaaa-~lance error has been found

Item 7 Check preacr ipt ion recorda for cloaeat weather aUtiona and use those data

Reaponae The local (Haverhill Wastewater Treataent Plant) precipitation recorda have been obtained They can be used ta select initial possible infiltration ratea which need not to be very accurate Since there are ao aany factors that can affect the actual infiltration rate in each area the final infiltration rates can only be determined through the flow model calibration

One other use of the local precipitation records ia to check whether the hypothetical conditions used in s ome of the scenarios ( i e Tests 1 through Test 6) can actually exist during the 1970s or not

NUS CORPORATION

~ Mr Robert Leger January 14 1991 Page Four

Item B Oeser ibe recharge estimate technique

Response The Hydrologic Evaluation of Landfill Performance (HELP) model was used to estimate the possible surface infiltration rates for the study area A 10shyfeet soil column representin9 the a verage thickness of the vadose zone with different types of surface coverage and hydraulic conductivity were used in simulation of the water bud9et balance The local climatological data was used when possible

As mentioned earlier these estimates need not to be very accurate because the final values and distribution of the infiltration rates were determined by the flow model calibration process

tea 9 Discuss hydrologic conditions to be aiaulated for long term transport IIOCeling How will estiutes of groundwater discharge (base flow in streallls) be made

Response Hydrolocaic conditions for long termmiddot simulations usually should be the site specific long term averaged conditiona But according to the IIOdeling results of some simulated hypothetical conditions we uy like to simulate some extre11e conditions too

Item 10 Discuss what the physical basis for the two h1yer 11odiel will be Are two layen sufficient

Response These queations can be better answered when the 3-D model results are available At this ti11e it is believed that the groundwater flow PAttern in the bedrock and till is in general the same as the flow in the overburden and a two-layer model will be sufficient for the study The interaction betweeen the two model layers needs to be considered in detail during the development of the 3-D model

Item 11 How will you justify the selection of the aquifer bottOIIl as proposed What are the consequences of this selection in light of contamination in bedrock and till

NUS COAPOAATION

Mr Robert Leqer January 14 1991 Pa9e Fi ve

Response The top of bedrock was selected as the bottom of the aquifer because the hydraulic conduct i vity of the bedrock is two orders of magnatude lower than the atratified drift Therefore the bedrock flow is minor when compared to overburden flow The hydraulic conductivity inputvalue of 90 ft day for the s tratified drift as derived from the pumpin9 teat reflects leaka9e from the bedrock

Item 12 Diacuaa rational for assigning atreambed properties Show stream bullodes of 9ain or loaa

Reaponae The locationbull and propertiea of atreaampD blocka are au11111111rhed in the attached table Water aurface elevationbull were aaaigned bAaed on the atatf gauge Maaureaenta alon9 the creek and were aet a a conatanu in the aodel The leaka9e factorbull were eatited by uein9 vertical hydraulic conductivitiea and ahea of the aurface area of the atre in each block Streaa-aquifer interactionbull depend on the) differencebull between the aiaulated groundwater elevationbull and aurtace water elevationbull aaaigned at theae blocka When the 9roundwater elevation ia higher the atreaa ia 9ainin9 otherwiae the at ream ia rechargin9 the aquifer Therefore the direction of water flow will be decided autOIUitically by the adel when aiaulating different puaping acenarioa A up ahowin9 the locationa of 9aining and loling aectiona of the creek for the IDOdel calibration and validation reaulta is provided

Item 13 Show reaulta and discuSI trans ient 1i11ulationa of puap teata (pa and 9roundwater level hydrographa)

Responae Plowpath only dbullulatea ateady-atate flow condit i ona Therefore the pumping teat waa approxiuted aa a ateady-atate puaping acenar io No hydrograph ia available at thi a time

NUS CORPORATION

Mr Robert Leger January 14 1991 Page Six

Additional explanation if necessary can be provided at our meeting

PMO-~ JRPaptd

Bncloaurea

CCI D Kelley (IPA) D Willey (IPA) wenc J tleparatek (DD) venc G Gerdner (IIUS) JD ChlouJ Orient (IIUS) rue 0216-0lOO

NUS CORPORATION

Meeting Summary

CCputer Modeling Groveland Wells Site

Supplemental MOM RIFS

Date December 20 1990 Place US EPA 90 Canal St

Boston Maaaachuaetta Project Supplemental MOM RIFS EPA W A No 04-lL32 NUS Project No 0216 Prepared by J Forrelli NUS Corporation

Attendeea r

PAr Robert Leger Remedial Project Mana9er (RPM) Richard Willey BydrOCJeOlOC)iat David Zeni ARCS I Contract Officer

USGS 1 Wayne Lathu

Maaaachuaetts DIP Jay ~paratek

HOI Corporation (IPA Contractor - ARCS I Progr) r J D Chiou Civil Zn9ineerModelin9 Specialiat Jeff Orient BydrOC)eOlOCJiat A Otrofaky Deputy Pr09r Mana9er Ja R rorralli Project Mana9er

Pureoser

Thh bulleting waa held at the requeat of IPA to diacuas the input conditione for the groundwater aodel under develos-ent by NUS in accordance with the work plan uendllent dated Deceaber 1990 (Qnly one meeting waa projected in the work plan - at 75 CCIIpletion Other additional aeetin9s may also be middot held during the adel development proceas

Diacusaion r

A table aUJUUrhing alta groundwater TCE levela annually for each well for the period 1910 through 1990 wa1 presented The table wa1 ~1ed on historical data bulls well as the current Supplementbull RI re1u1ts Re1ulta for wells allllpled aore thbulln once ln a year were 1veraged Selected d1t1 will be used for model calibration and validation

-l shy

-_ It waa agreed that OCE will not be modeled althouqh OCE could be modeled independently TCE and OCE have different densities and decay rates and can bull t be modeled as a total mass A aecond data table for OCE will be prepared

Sufficient data for transport model calibrationvalidation exiata The calibration and validation process waa discussed The model will be con1tructed on the bash of the 1983 TCE data set calibrated udng 1984 TCE data set and validated with the 1984-90 TCE data aets

The tran1port model interpolates actual values to determine TCE

I I

leveh between data pointbull vertically and horizontally

Changea in TCE levela re1ult from dilperlion and decay Total 1aa11 of TCE in the aodel will reuin conatant becau1e no decay will be lillulated

Sea1onal differencebull wouldnt be accounted for with thh llodel Model inputoutput h aeauaed for a eteady bulltate condition with c011pariaona aade on a annual inatead of aea1onal bJaia ~~ The llodel area 11 lar9er than the area IIOdeled by ERT Exhibita of thbull aodel 9rid bott011 of aquifer and infiltration rate eatiaatea were preeentect Boundary conditionbull and IIOdel reaolution were diiCUIIed

aeaulta of-the are recent Cheaterton anitoring will be included in the cheaical data bale

A printout of reaidual hydraulic heada will be aupplied to EPA with the adel re1ulta

Eatiaatea of detailed aaaa flux are very difficult becauae of the aurface watergroundwater interaction

Preliainary tlovpath adel re1ulta conahting of exhibitbull depicting hydraulic head contoura and groundwater flow velocity were pre1ented for the following acenarioa

1 No pullpin9 2 1990 puaping teet 3 Sta No 1 at 600 9pm Sta No 2 at 500 9pm 4 Sta No 1 at 600 9pm 5 Sta No 2 at 500 gpm

The next meeting waa tentatively aet for January 11 1991

The aeeting adjourned at approximately 330 pa

-2shy

UNITED STATES EN VIRONMENTAL PROTECTI ON AGENC Y REGION I

JFK Federa l Build1ng Boston MA 02203-2211

MEMORANDUM

DATE Deceoer 24 1910

SUBJ ~~ mer 1c e l ground-water ~oae i 1ng Grovela-o ~we ll s S1te Gr ove l an e t-14

FROM

TO

i rgte llicmiddot ~ltln t~ 11 st )f 1te ns reel to te aao~esec cy t1U~ - IF t nerc ar~ tny oestlcns t e J s l I O OE- r e e reO to ltayne ~acr al

vSG S f middot~1i - 5t5-t - ~

f ffVU I C c~ rgt-ec t ~ a t 11 i l st coe rlt S l gra l C S S~-middotsatmiddotmiddot )r

wmiddot~n N Lmiddot ~ middot s e~torts to oa t e r a umiddoter u-at we war t t he to oroouce a gJl J aef ens 1 o middotmiddot t~ mcmiddotoel

Q 1bull J- - o v oe wn t te~ SLa r y ot mae t g

1 i=lno v cbull maos 1al l a t sane s c a l e S 10middot~ 1 ng e +c ICmiddotI-111

nvomiddotmiddot a ~-bulll c co ~1 ou middot t1 1 1ty Ol StlOut on re~narce middotJI~tr ll 1 1 bull stat1f 1e c dnft anl t 1 l i at hr~ surfac e on t toM o f ao w1 f e r I where oecroc~ c t 1 I middot

s t rearr noles

l lr Ol de lap f middot g or e ~ 3ncw1r1g t t e d l StrlOJt l c n aro Tla 3 1 tl~~

of reslOJal water middotlE-ve ls for t ne following simu lati o s

measuPec I 3 - 16-9(bull l nor- oumoi ng cona i t 1ons vs t tnal calibrat 1o n va lues

measured I 3-90) p umo1ng conditton vs s 1mulatea values

4 1 Dtscuss cnter1a f o r sat 1sfac t o q ca l 1orat l On o f moo~ l

5) Simulate other oumo t ests

St a 0 - nemiddot bull 1 St COS~ru t e J

- 1~17

~ ta tmiddoton - ~lto r e ~ c c l t middotJ c t e J

s hou i o not oe modelec e xo 1a 1n wn y t

Mr Robert Leger January 14 1991 Page Three

Item 5 Simulate other pump tests Sta No 1 - when first constructed - 1987 Sta No 2 -when constructed (if not possible or should not be modeled explain why)

Response No accurate pumping rate was available for all three cases listed Although the water elevations in 6 monitoring wells are available for the 1987 pumping teat it will not be meaningful to com~re model outputs to measured water elevations with an aaaumed pumping rate

Item 6 Provide water balance data for all aimuhted (items 3 and 5) Com~re discharge measurements with Isimulations for 87 and 90 pump tests

Reaponae 1 The Plow~th Model does not provide an internal Naashy ~~ balance check It is very time conaumin9 to check the uaa balance in detail aanually because every surface water and constant head blocks t09ether with all the blocka with surface infiltration need to be conlidered in the cAlculation one by one However the aha of liaulated capture aonea and the surface infiltration ratea in the zones were used to calculated the water supply available to puaping Ita No 1 (andor 2) for each puaping scenario simulated By coaparing the puaping rates uaed and the water supply available no obvious aaaa-~lance error has been found

Item 7 Check preacr ipt ion recorda for cloaeat weather aUtiona and use those data

Reaponae The local (Haverhill Wastewater Treataent Plant) precipitation recorda have been obtained They can be used ta select initial possible infiltration ratea which need not to be very accurate Since there are ao aany factors that can affect the actual infiltration rate in each area the final infiltration rates can only be determined through the flow model calibration

One other use of the local precipitation records ia to check whether the hypothetical conditions used in s ome of the scenarios ( i e Tests 1 through Test 6) can actually exist during the 1970s or not

NUS CORPORATION

~ Mr Robert Leger January 14 1991 Page Four

Item B Oeser ibe recharge estimate technique

Response The Hydrologic Evaluation of Landfill Performance (HELP) model was used to estimate the possible surface infiltration rates for the study area A 10shyfeet soil column representin9 the a verage thickness of the vadose zone with different types of surface coverage and hydraulic conductivity were used in simulation of the water bud9et balance The local climatological data was used when possible

As mentioned earlier these estimates need not to be very accurate because the final values and distribution of the infiltration rates were determined by the flow model calibration process

tea 9 Discuss hydrologic conditions to be aiaulated for long term transport IIOCeling How will estiutes of groundwater discharge (base flow in streallls) be made

Response Hydrolocaic conditions for long termmiddot simulations usually should be the site specific long term averaged conditiona But according to the IIOdeling results of some simulated hypothetical conditions we uy like to simulate some extre11e conditions too

Item 10 Discuss what the physical basis for the two h1yer 11odiel will be Are two layen sufficient

Response These queations can be better answered when the 3-D model results are available At this ti11e it is believed that the groundwater flow PAttern in the bedrock and till is in general the same as the flow in the overburden and a two-layer model will be sufficient for the study The interaction betweeen the two model layers needs to be considered in detail during the development of the 3-D model

Item 11 How will you justify the selection of the aquifer bottOIIl as proposed What are the consequences of this selection in light of contamination in bedrock and till

NUS COAPOAATION

Mr Robert Leqer January 14 1991 Pa9e Fi ve

Response The top of bedrock was selected as the bottom of the aquifer because the hydraulic conduct i vity of the bedrock is two orders of magnatude lower than the atratified drift Therefore the bedrock flow is minor when compared to overburden flow The hydraulic conductivity inputvalue of 90 ft day for the s tratified drift as derived from the pumpin9 teat reflects leaka9e from the bedrock

Item 12 Diacuaa rational for assigning atreambed properties Show stream bullodes of 9ain or loaa

Reaponae The locationbull and propertiea of atreaampD blocka are au11111111rhed in the attached table Water aurface elevationbull were aaaigned bAaed on the atatf gauge Maaureaenta alon9 the creek and were aet a a conatanu in the aodel The leaka9e factorbull were eatited by uein9 vertical hydraulic conductivitiea and ahea of the aurface area of the atre in each block Streaa-aquifer interactionbull depend on the) differencebull between the aiaulated groundwater elevationbull and aurtace water elevationbull aaaigned at theae blocka When the 9roundwater elevation ia higher the atreaa ia 9ainin9 otherwiae the at ream ia rechargin9 the aquifer Therefore the direction of water flow will be decided autOIUitically by the adel when aiaulating different puaping acenarioa A up ahowin9 the locationa of 9aining and loling aectiona of the creek for the IDOdel calibration and validation reaulta is provided

Item 13 Show reaulta and discuSI trans ient 1i11ulationa of puap teata (pa and 9roundwater level hydrographa)

Responae Plowpath only dbullulatea ateady-atate flow condit i ona Therefore the pumping teat waa approxiuted aa a ateady-atate puaping acenar io No hydrograph ia available at thi a time

NUS CORPORATION

Mr Robert Leger January 14 1991 Page Six

Additional explanation if necessary can be provided at our meeting

PMO-~ JRPaptd

Bncloaurea

CCI D Kelley (IPA) D Willey (IPA) wenc J tleparatek (DD) venc G Gerdner (IIUS) JD ChlouJ Orient (IIUS) rue 0216-0lOO

NUS CORPORATION

Meeting Summary

CCputer Modeling Groveland Wells Site

Supplemental MOM RIFS

Date December 20 1990 Place US EPA 90 Canal St

Boston Maaaachuaetta Project Supplemental MOM RIFS EPA W A No 04-lL32 NUS Project No 0216 Prepared by J Forrelli NUS Corporation

Attendeea r

PAr Robert Leger Remedial Project Mana9er (RPM) Richard Willey BydrOCJeOlOC)iat David Zeni ARCS I Contract Officer

USGS 1 Wayne Lathu

Maaaachuaetts DIP Jay ~paratek

HOI Corporation (IPA Contractor - ARCS I Progr) r J D Chiou Civil Zn9ineerModelin9 Specialiat Jeff Orient BydrOC)eOlOCJiat A Otrofaky Deputy Pr09r Mana9er Ja R rorralli Project Mana9er

Pureoser

Thh bulleting waa held at the requeat of IPA to diacuas the input conditione for the groundwater aodel under develos-ent by NUS in accordance with the work plan uendllent dated Deceaber 1990 (Qnly one meeting waa projected in the work plan - at 75 CCIIpletion Other additional aeetin9s may also be middot held during the adel development proceas

Diacusaion r

A table aUJUUrhing alta groundwater TCE levela annually for each well for the period 1910 through 1990 wa1 presented The table wa1 ~1ed on historical data bulls well as the current Supplementbull RI re1u1ts Re1ulta for wells allllpled aore thbulln once ln a year were 1veraged Selected d1t1 will be used for model calibration and validation

-l shy

-_ It waa agreed that OCE will not be modeled althouqh OCE could be modeled independently TCE and OCE have different densities and decay rates and can bull t be modeled as a total mass A aecond data table for OCE will be prepared

Sufficient data for transport model calibrationvalidation exiata The calibration and validation process waa discussed The model will be con1tructed on the bash of the 1983 TCE data set calibrated udng 1984 TCE data set and validated with the 1984-90 TCE data aets

The tran1port model interpolates actual values to determine TCE

I I

leveh between data pointbull vertically and horizontally

Changea in TCE levela re1ult from dilperlion and decay Total 1aa11 of TCE in the aodel will reuin conatant becau1e no decay will be lillulated

Sea1onal differencebull wouldnt be accounted for with thh llodel Model inputoutput h aeauaed for a eteady bulltate condition with c011pariaona aade on a annual inatead of aea1onal bJaia ~~ The llodel area 11 lar9er than the area IIOdeled by ERT Exhibita of thbull aodel 9rid bott011 of aquifer and infiltration rate eatiaatea were preeentect Boundary conditionbull and IIOdel reaolution were diiCUIIed

aeaulta of-the are recent Cheaterton anitoring will be included in the cheaical data bale

A printout of reaidual hydraulic heada will be aupplied to EPA with the adel re1ulta

Eatiaatea of detailed aaaa flux are very difficult becauae of the aurface watergroundwater interaction

Preliainary tlovpath adel re1ulta conahting of exhibitbull depicting hydraulic head contoura and groundwater flow velocity were pre1ented for the following acenarioa

1 No pullpin9 2 1990 puaping teet 3 Sta No 1 at 600 9pm Sta No 2 at 500 9pm 4 Sta No 1 at 600 9pm 5 Sta No 2 at 500 gpm

The next meeting waa tentatively aet for January 11 1991

The aeeting adjourned at approximately 330 pa

-2shy

UNITED STATES EN VIRONMENTAL PROTECTI ON AGENC Y REGION I

JFK Federa l Build1ng Boston MA 02203-2211

MEMORANDUM

DATE Deceoer 24 1910

SUBJ ~~ mer 1c e l ground-water ~oae i 1ng Grovela-o ~we ll s S1te Gr ove l an e t-14

FROM

TO

i rgte llicmiddot ~ltln t~ 11 st )f 1te ns reel to te aao~esec cy t1U~ - IF t nerc ar~ tny oestlcns t e J s l I O OE- r e e reO to ltayne ~acr al

vSG S f middot~1i - 5t5-t - ~

f ffVU I C c~ rgt-ec t ~ a t 11 i l st coe rlt S l gra l C S S~-middotsatmiddotmiddot )r

wmiddot~n N Lmiddot ~ middot s e~torts to oa t e r a umiddoter u-at we war t t he to oroouce a gJl J aef ens 1 o middotmiddot t~ mcmiddotoel

Q 1bull J- - o v oe wn t te~ SLa r y ot mae t g

1 i=lno v cbull maos 1al l a t sane s c a l e S 10middot~ 1 ng e +c ICmiddotI-111

nvomiddotmiddot a ~-bulll c co ~1 ou middot t1 1 1ty Ol StlOut on re~narce middotJI~tr ll 1 1 bull stat1f 1e c dnft anl t 1 l i at hr~ surfac e on t toM o f ao w1 f e r I where oecroc~ c t 1 I middot

s t rearr noles

l lr Ol de lap f middot g or e ~ 3ncw1r1g t t e d l StrlOJt l c n aro Tla 3 1 tl~~

of reslOJal water middotlE-ve ls for t ne following simu lati o s

measuPec I 3 - 16-9(bull l nor- oumoi ng cona i t 1ons vs t tnal calibrat 1o n va lues

measured I 3-90) p umo1ng conditton vs s 1mulatea values

4 1 Dtscuss cnter1a f o r sat 1sfac t o q ca l 1orat l On o f moo~ l

5) Simulate other oumo t ests

St a 0 - nemiddot bull 1 St COS~ru t e J

- 1~17

~ ta tmiddoton - ~lto r e ~ c c l t middotJ c t e J

s hou i o not oe modelec e xo 1a 1n wn y t

~ Mr Robert Leger January 14 1991 Page Four

Item B Oeser ibe recharge estimate technique

Response The Hydrologic Evaluation of Landfill Performance (HELP) model was used to estimate the possible surface infiltration rates for the study area A 10shyfeet soil column representin9 the a verage thickness of the vadose zone with different types of surface coverage and hydraulic conductivity were used in simulation of the water bud9et balance The local climatological data was used when possible

As mentioned earlier these estimates need not to be very accurate because the final values and distribution of the infiltration rates were determined by the flow model calibration process

tea 9 Discuss hydrologic conditions to be aiaulated for long term transport IIOCeling How will estiutes of groundwater discharge (base flow in streallls) be made

Response Hydrolocaic conditions for long termmiddot simulations usually should be the site specific long term averaged conditiona But according to the IIOdeling results of some simulated hypothetical conditions we uy like to simulate some extre11e conditions too

Item 10 Discuss what the physical basis for the two h1yer 11odiel will be Are two layen sufficient

Response These queations can be better answered when the 3-D model results are available At this ti11e it is believed that the groundwater flow PAttern in the bedrock and till is in general the same as the flow in the overburden and a two-layer model will be sufficient for the study The interaction betweeen the two model layers needs to be considered in detail during the development of the 3-D model

Item 11 How will you justify the selection of the aquifer bottOIIl as proposed What are the consequences of this selection in light of contamination in bedrock and till

NUS COAPOAATION

Mr Robert Leqer January 14 1991 Pa9e Fi ve

Response The top of bedrock was selected as the bottom of the aquifer because the hydraulic conduct i vity of the bedrock is two orders of magnatude lower than the atratified drift Therefore the bedrock flow is minor when compared to overburden flow The hydraulic conductivity inputvalue of 90 ft day for the s tratified drift as derived from the pumpin9 teat reflects leaka9e from the bedrock

Item 12 Diacuaa rational for assigning atreambed properties Show stream bullodes of 9ain or loaa

Reaponae The locationbull and propertiea of atreaampD blocka are au11111111rhed in the attached table Water aurface elevationbull were aaaigned bAaed on the atatf gauge Maaureaenta alon9 the creek and were aet a a conatanu in the aodel The leaka9e factorbull were eatited by uein9 vertical hydraulic conductivitiea and ahea of the aurface area of the atre in each block Streaa-aquifer interactionbull depend on the) differencebull between the aiaulated groundwater elevationbull and aurtace water elevationbull aaaigned at theae blocka When the 9roundwater elevation ia higher the atreaa ia 9ainin9 otherwiae the at ream ia rechargin9 the aquifer Therefore the direction of water flow will be decided autOIUitically by the adel when aiaulating different puaping acenarioa A up ahowin9 the locationa of 9aining and loling aectiona of the creek for the IDOdel calibration and validation reaulta is provided

Item 13 Show reaulta and discuSI trans ient 1i11ulationa of puap teata (pa and 9roundwater level hydrographa)

Responae Plowpath only dbullulatea ateady-atate flow condit i ona Therefore the pumping teat waa approxiuted aa a ateady-atate puaping acenar io No hydrograph ia available at thi a time

NUS CORPORATION

Mr Robert Leger January 14 1991 Page Six

Additional explanation if necessary can be provided at our meeting

PMO-~ JRPaptd

Bncloaurea

CCI D Kelley (IPA) D Willey (IPA) wenc J tleparatek (DD) venc G Gerdner (IIUS) JD ChlouJ Orient (IIUS) rue 0216-0lOO

NUS CORPORATION

Meeting Summary

CCputer Modeling Groveland Wells Site

Supplemental MOM RIFS

Date December 20 1990 Place US EPA 90 Canal St

Boston Maaaachuaetta Project Supplemental MOM RIFS EPA W A No 04-lL32 NUS Project No 0216 Prepared by J Forrelli NUS Corporation

Attendeea r

PAr Robert Leger Remedial Project Mana9er (RPM) Richard Willey BydrOCJeOlOC)iat David Zeni ARCS I Contract Officer

USGS 1 Wayne Lathu

Maaaachuaetts DIP Jay ~paratek

HOI Corporation (IPA Contractor - ARCS I Progr) r J D Chiou Civil Zn9ineerModelin9 Specialiat Jeff Orient BydrOC)eOlOCJiat A Otrofaky Deputy Pr09r Mana9er Ja R rorralli Project Mana9er

Pureoser

Thh bulleting waa held at the requeat of IPA to diacuas the input conditione for the groundwater aodel under develos-ent by NUS in accordance with the work plan uendllent dated Deceaber 1990 (Qnly one meeting waa projected in the work plan - at 75 CCIIpletion Other additional aeetin9s may also be middot held during the adel development proceas

Diacusaion r

A table aUJUUrhing alta groundwater TCE levela annually for each well for the period 1910 through 1990 wa1 presented The table wa1 ~1ed on historical data bulls well as the current Supplementbull RI re1u1ts Re1ulta for wells allllpled aore thbulln once ln a year were 1veraged Selected d1t1 will be used for model calibration and validation

-l shy

-_ It waa agreed that OCE will not be modeled althouqh OCE could be modeled independently TCE and OCE have different densities and decay rates and can bull t be modeled as a total mass A aecond data table for OCE will be prepared

Sufficient data for transport model calibrationvalidation exiata The calibration and validation process waa discussed The model will be con1tructed on the bash of the 1983 TCE data set calibrated udng 1984 TCE data set and validated with the 1984-90 TCE data aets

The tran1port model interpolates actual values to determine TCE

I I

leveh between data pointbull vertically and horizontally

Changea in TCE levela re1ult from dilperlion and decay Total 1aa11 of TCE in the aodel will reuin conatant becau1e no decay will be lillulated

Sea1onal differencebull wouldnt be accounted for with thh llodel Model inputoutput h aeauaed for a eteady bulltate condition with c011pariaona aade on a annual inatead of aea1onal bJaia ~~ The llodel area 11 lar9er than the area IIOdeled by ERT Exhibita of thbull aodel 9rid bott011 of aquifer and infiltration rate eatiaatea were preeentect Boundary conditionbull and IIOdel reaolution were diiCUIIed

aeaulta of-the are recent Cheaterton anitoring will be included in the cheaical data bale

A printout of reaidual hydraulic heada will be aupplied to EPA with the adel re1ulta

Eatiaatea of detailed aaaa flux are very difficult becauae of the aurface watergroundwater interaction

Preliainary tlovpath adel re1ulta conahting of exhibitbull depicting hydraulic head contoura and groundwater flow velocity were pre1ented for the following acenarioa

1 No pullpin9 2 1990 puaping teet 3 Sta No 1 at 600 9pm Sta No 2 at 500 9pm 4 Sta No 1 at 600 9pm 5 Sta No 2 at 500 gpm

The next meeting waa tentatively aet for January 11 1991

The aeeting adjourned at approximately 330 pa

-2shy

UNITED STATES EN VIRONMENTAL PROTECTI ON AGENC Y REGION I

JFK Federa l Build1ng Boston MA 02203-2211

MEMORANDUM

DATE Deceoer 24 1910

SUBJ ~~ mer 1c e l ground-water ~oae i 1ng Grovela-o ~we ll s S1te Gr ove l an e t-14

FROM

TO

i rgte llicmiddot ~ltln t~ 11 st )f 1te ns reel to te aao~esec cy t1U~ - IF t nerc ar~ tny oestlcns t e J s l I O OE- r e e reO to ltayne ~acr al

vSG S f middot~1i - 5t5-t - ~

f ffVU I C c~ rgt-ec t ~ a t 11 i l st coe rlt S l gra l C S S~-middotsatmiddotmiddot )r

wmiddot~n N Lmiddot ~ middot s e~torts to oa t e r a umiddoter u-at we war t t he to oroouce a gJl J aef ens 1 o middotmiddot t~ mcmiddotoel

Q 1bull J- - o v oe wn t te~ SLa r y ot mae t g

1 i=lno v cbull maos 1al l a t sane s c a l e S 10middot~ 1 ng e +c ICmiddotI-111

nvomiddotmiddot a ~-bulll c co ~1 ou middot t1 1 1ty Ol StlOut on re~narce middotJI~tr ll 1 1 bull stat1f 1e c dnft anl t 1 l i at hr~ surfac e on t toM o f ao w1 f e r I where oecroc~ c t 1 I middot

s t rearr noles

l lr Ol de lap f middot g or e ~ 3ncw1r1g t t e d l StrlOJt l c n aro Tla 3 1 tl~~

of reslOJal water middotlE-ve ls for t ne following simu lati o s

measuPec I 3 - 16-9(bull l nor- oumoi ng cona i t 1ons vs t tnal calibrat 1o n va lues

measured I 3-90) p umo1ng conditton vs s 1mulatea values

4 1 Dtscuss cnter1a f o r sat 1sfac t o q ca l 1orat l On o f moo~ l

5) Simulate other oumo t ests

St a 0 - nemiddot bull 1 St COS~ru t e J

- 1~17

~ ta tmiddoton - ~lto r e ~ c c l t middotJ c t e J

s hou i o not oe modelec e xo 1a 1n wn y t

Mr Robert Leqer January 14 1991 Pa9e Fi ve

Response The top of bedrock was selected as the bottom of the aquifer because the hydraulic conduct i vity of the bedrock is two orders of magnatude lower than the atratified drift Therefore the bedrock flow is minor when compared to overburden flow The hydraulic conductivity inputvalue of 90 ft day for the s tratified drift as derived from the pumpin9 teat reflects leaka9e from the bedrock

Item 12 Diacuaa rational for assigning atreambed properties Show stream bullodes of 9ain or loaa

Reaponae The locationbull and propertiea of atreaampD blocka are au11111111rhed in the attached table Water aurface elevationbull were aaaigned bAaed on the atatf gauge Maaureaenta alon9 the creek and were aet a a conatanu in the aodel The leaka9e factorbull were eatited by uein9 vertical hydraulic conductivitiea and ahea of the aurface area of the atre in each block Streaa-aquifer interactionbull depend on the) differencebull between the aiaulated groundwater elevationbull and aurtace water elevationbull aaaigned at theae blocka When the 9roundwater elevation ia higher the atreaa ia 9ainin9 otherwiae the at ream ia rechargin9 the aquifer Therefore the direction of water flow will be decided autOIUitically by the adel when aiaulating different puaping acenarioa A up ahowin9 the locationa of 9aining and loling aectiona of the creek for the IDOdel calibration and validation reaulta is provided

Item 13 Show reaulta and discuSI trans ient 1i11ulationa of puap teata (pa and 9roundwater level hydrographa)

Responae Plowpath only dbullulatea ateady-atate flow condit i ona Therefore the pumping teat waa approxiuted aa a ateady-atate puaping acenar io No hydrograph ia available at thi a time

NUS CORPORATION

Mr Robert Leger January 14 1991 Page Six

Additional explanation if necessary can be provided at our meeting

PMO-~ JRPaptd

Bncloaurea

CCI D Kelley (IPA) D Willey (IPA) wenc J tleparatek (DD) venc G Gerdner (IIUS) JD ChlouJ Orient (IIUS) rue 0216-0lOO

NUS CORPORATION

Meeting Summary

CCputer Modeling Groveland Wells Site

Supplemental MOM RIFS

Date December 20 1990 Place US EPA 90 Canal St

Boston Maaaachuaetta Project Supplemental MOM RIFS EPA W A No 04-lL32 NUS Project No 0216 Prepared by J Forrelli NUS Corporation

Attendeea r

PAr Robert Leger Remedial Project Mana9er (RPM) Richard Willey BydrOCJeOlOC)iat David Zeni ARCS I Contract Officer

USGS 1 Wayne Lathu

Maaaachuaetts DIP Jay ~paratek

HOI Corporation (IPA Contractor - ARCS I Progr) r J D Chiou Civil Zn9ineerModelin9 Specialiat Jeff Orient BydrOC)eOlOCJiat A Otrofaky Deputy Pr09r Mana9er Ja R rorralli Project Mana9er

Pureoser

Thh bulleting waa held at the requeat of IPA to diacuas the input conditione for the groundwater aodel under develos-ent by NUS in accordance with the work plan uendllent dated Deceaber 1990 (Qnly one meeting waa projected in the work plan - at 75 CCIIpletion Other additional aeetin9s may also be middot held during the adel development proceas

Diacusaion r

A table aUJUUrhing alta groundwater TCE levela annually for each well for the period 1910 through 1990 wa1 presented The table wa1 ~1ed on historical data bulls well as the current Supplementbull RI re1u1ts Re1ulta for wells allllpled aore thbulln once ln a year were 1veraged Selected d1t1 will be used for model calibration and validation

-l shy

-_ It waa agreed that OCE will not be modeled althouqh OCE could be modeled independently TCE and OCE have different densities and decay rates and can bull t be modeled as a total mass A aecond data table for OCE will be prepared

Sufficient data for transport model calibrationvalidation exiata The calibration and validation process waa discussed The model will be con1tructed on the bash of the 1983 TCE data set calibrated udng 1984 TCE data set and validated with the 1984-90 TCE data aets

The tran1port model interpolates actual values to determine TCE

I I

leveh between data pointbull vertically and horizontally

Changea in TCE levela re1ult from dilperlion and decay Total 1aa11 of TCE in the aodel will reuin conatant becau1e no decay will be lillulated

Sea1onal differencebull wouldnt be accounted for with thh llodel Model inputoutput h aeauaed for a eteady bulltate condition with c011pariaona aade on a annual inatead of aea1onal bJaia ~~ The llodel area 11 lar9er than the area IIOdeled by ERT Exhibita of thbull aodel 9rid bott011 of aquifer and infiltration rate eatiaatea were preeentect Boundary conditionbull and IIOdel reaolution were diiCUIIed

aeaulta of-the are recent Cheaterton anitoring will be included in the cheaical data bale

A printout of reaidual hydraulic heada will be aupplied to EPA with the adel re1ulta

Eatiaatea of detailed aaaa flux are very difficult becauae of the aurface watergroundwater interaction

Preliainary tlovpath adel re1ulta conahting of exhibitbull depicting hydraulic head contoura and groundwater flow velocity were pre1ented for the following acenarioa

1 No pullpin9 2 1990 puaping teet 3 Sta No 1 at 600 9pm Sta No 2 at 500 9pm 4 Sta No 1 at 600 9pm 5 Sta No 2 at 500 gpm

The next meeting waa tentatively aet for January 11 1991

The aeeting adjourned at approximately 330 pa

-2shy

UNITED STATES EN VIRONMENTAL PROTECTI ON AGENC Y REGION I

JFK Federa l Build1ng Boston MA 02203-2211

MEMORANDUM

DATE Deceoer 24 1910

SUBJ ~~ mer 1c e l ground-water ~oae i 1ng Grovela-o ~we ll s S1te Gr ove l an e t-14

FROM

TO

i rgte llicmiddot ~ltln t~ 11 st )f 1te ns reel to te aao~esec cy t1U~ - IF t nerc ar~ tny oestlcns t e J s l I O OE- r e e reO to ltayne ~acr al

vSG S f middot~1i - 5t5-t - ~

f ffVU I C c~ rgt-ec t ~ a t 11 i l st coe rlt S l gra l C S S~-middotsatmiddotmiddot )r

wmiddot~n N Lmiddot ~ middot s e~torts to oa t e r a umiddoter u-at we war t t he to oroouce a gJl J aef ens 1 o middotmiddot t~ mcmiddotoel

Q 1bull J- - o v oe wn t te~ SLa r y ot mae t g

1 i=lno v cbull maos 1al l a t sane s c a l e S 10middot~ 1 ng e +c ICmiddotI-111

nvomiddotmiddot a ~-bulll c co ~1 ou middot t1 1 1ty Ol StlOut on re~narce middotJI~tr ll 1 1 bull stat1f 1e c dnft anl t 1 l i at hr~ surfac e on t toM o f ao w1 f e r I where oecroc~ c t 1 I middot

s t rearr noles

l lr Ol de lap f middot g or e ~ 3ncw1r1g t t e d l StrlOJt l c n aro Tla 3 1 tl~~

of reslOJal water middotlE-ve ls for t ne following simu lati o s

measuPec I 3 - 16-9(bull l nor- oumoi ng cona i t 1ons vs t tnal calibrat 1o n va lues

measured I 3-90) p umo1ng conditton vs s 1mulatea values

4 1 Dtscuss cnter1a f o r sat 1sfac t o q ca l 1orat l On o f moo~ l

5) Simulate other oumo t ests

St a 0 - nemiddot bull 1 St COS~ru t e J

- 1~17

~ ta tmiddoton - ~lto r e ~ c c l t middotJ c t e J

s hou i o not oe modelec e xo 1a 1n wn y t

Mr Robert Leger January 14 1991 Page Six

Additional explanation if necessary can be provided at our meeting

PMO-~ JRPaptd

Bncloaurea

CCI D Kelley (IPA) D Willey (IPA) wenc J tleparatek (DD) venc G Gerdner (IIUS) JD ChlouJ Orient (IIUS) rue 0216-0lOO

NUS CORPORATION

Meeting Summary

CCputer Modeling Groveland Wells Site

Supplemental MOM RIFS

Date December 20 1990 Place US EPA 90 Canal St

Boston Maaaachuaetta Project Supplemental MOM RIFS EPA W A No 04-lL32 NUS Project No 0216 Prepared by J Forrelli NUS Corporation

Attendeea r

PAr Robert Leger Remedial Project Mana9er (RPM) Richard Willey BydrOCJeOlOC)iat David Zeni ARCS I Contract Officer

USGS 1 Wayne Lathu

Maaaachuaetts DIP Jay ~paratek

HOI Corporation (IPA Contractor - ARCS I Progr) r J D Chiou Civil Zn9ineerModelin9 Specialiat Jeff Orient BydrOC)eOlOCJiat A Otrofaky Deputy Pr09r Mana9er Ja R rorralli Project Mana9er

Pureoser

Thh bulleting waa held at the requeat of IPA to diacuas the input conditione for the groundwater aodel under develos-ent by NUS in accordance with the work plan uendllent dated Deceaber 1990 (Qnly one meeting waa projected in the work plan - at 75 CCIIpletion Other additional aeetin9s may also be middot held during the adel development proceas

Diacusaion r

A table aUJUUrhing alta groundwater TCE levela annually for each well for the period 1910 through 1990 wa1 presented The table wa1 ~1ed on historical data bulls well as the current Supplementbull RI re1u1ts Re1ulta for wells allllpled aore thbulln once ln a year were 1veraged Selected d1t1 will be used for model calibration and validation

-l shy

-_ It waa agreed that OCE will not be modeled althouqh OCE could be modeled independently TCE and OCE have different densities and decay rates and can bull t be modeled as a total mass A aecond data table for OCE will be prepared

Sufficient data for transport model calibrationvalidation exiata The calibration and validation process waa discussed The model will be con1tructed on the bash of the 1983 TCE data set calibrated udng 1984 TCE data set and validated with the 1984-90 TCE data aets

The tran1port model interpolates actual values to determine TCE

I I

leveh between data pointbull vertically and horizontally

Changea in TCE levela re1ult from dilperlion and decay Total 1aa11 of TCE in the aodel will reuin conatant becau1e no decay will be lillulated

Sea1onal differencebull wouldnt be accounted for with thh llodel Model inputoutput h aeauaed for a eteady bulltate condition with c011pariaona aade on a annual inatead of aea1onal bJaia ~~ The llodel area 11 lar9er than the area IIOdeled by ERT Exhibita of thbull aodel 9rid bott011 of aquifer and infiltration rate eatiaatea were preeentect Boundary conditionbull and IIOdel reaolution were diiCUIIed

aeaulta of-the are recent Cheaterton anitoring will be included in the cheaical data bale

A printout of reaidual hydraulic heada will be aupplied to EPA with the adel re1ulta

Eatiaatea of detailed aaaa flux are very difficult becauae of the aurface watergroundwater interaction

Preliainary tlovpath adel re1ulta conahting of exhibitbull depicting hydraulic head contoura and groundwater flow velocity were pre1ented for the following acenarioa

1 No pullpin9 2 1990 puaping teet 3 Sta No 1 at 600 9pm Sta No 2 at 500 9pm 4 Sta No 1 at 600 9pm 5 Sta No 2 at 500 gpm

The next meeting waa tentatively aet for January 11 1991

The aeeting adjourned at approximately 330 pa

-2shy

UNITED STATES EN VIRONMENTAL PROTECTI ON AGENC Y REGION I

JFK Federa l Build1ng Boston MA 02203-2211

MEMORANDUM

DATE Deceoer 24 1910

SUBJ ~~ mer 1c e l ground-water ~oae i 1ng Grovela-o ~we ll s S1te Gr ove l an e t-14

FROM

TO

i rgte llicmiddot ~ltln t~ 11 st )f 1te ns reel to te aao~esec cy t1U~ - IF t nerc ar~ tny oestlcns t e J s l I O OE- r e e reO to ltayne ~acr al

vSG S f middot~1i - 5t5-t - ~

f ffVU I C c~ rgt-ec t ~ a t 11 i l st coe rlt S l gra l C S S~-middotsatmiddotmiddot )r

wmiddot~n N Lmiddot ~ middot s e~torts to oa t e r a umiddoter u-at we war t t he to oroouce a gJl J aef ens 1 o middotmiddot t~ mcmiddotoel

Q 1bull J- - o v oe wn t te~ SLa r y ot mae t g

1 i=lno v cbull maos 1al l a t sane s c a l e S 10middot~ 1 ng e +c ICmiddotI-111

nvomiddotmiddot a ~-bulll c co ~1 ou middot t1 1 1ty Ol StlOut on re~narce middotJI~tr ll 1 1 bull stat1f 1e c dnft anl t 1 l i at hr~ surfac e on t toM o f ao w1 f e r I where oecroc~ c t 1 I middot

s t rearr noles

l lr Ol de lap f middot g or e ~ 3ncw1r1g t t e d l StrlOJt l c n aro Tla 3 1 tl~~

of reslOJal water middotlE-ve ls for t ne following simu lati o s

measuPec I 3 - 16-9(bull l nor- oumoi ng cona i t 1ons vs t tnal calibrat 1o n va lues

measured I 3-90) p umo1ng conditton vs s 1mulatea values

4 1 Dtscuss cnter1a f o r sat 1sfac t o q ca l 1orat l On o f moo~ l

5) Simulate other oumo t ests

St a 0 - nemiddot bull 1 St COS~ru t e J

- 1~17

~ ta tmiddoton - ~lto r e ~ c c l t middotJ c t e J

s hou i o not oe modelec e xo 1a 1n wn y t

Meeting Summary

CCputer Modeling Groveland Wells Site

Supplemental MOM RIFS

Date December 20 1990 Place US EPA 90 Canal St

Boston Maaaachuaetta Project Supplemental MOM RIFS EPA W A No 04-lL32 NUS Project No 0216 Prepared by J Forrelli NUS Corporation

Attendeea r

PAr Robert Leger Remedial Project Mana9er (RPM) Richard Willey BydrOCJeOlOC)iat David Zeni ARCS I Contract Officer

USGS 1 Wayne Lathu

Maaaachuaetts DIP Jay ~paratek

HOI Corporation (IPA Contractor - ARCS I Progr) r J D Chiou Civil Zn9ineerModelin9 Specialiat Jeff Orient BydrOC)eOlOCJiat A Otrofaky Deputy Pr09r Mana9er Ja R rorralli Project Mana9er

Pureoser

Thh bulleting waa held at the requeat of IPA to diacuas the input conditione for the groundwater aodel under develos-ent by NUS in accordance with the work plan uendllent dated Deceaber 1990 (Qnly one meeting waa projected in the work plan - at 75 CCIIpletion Other additional aeetin9s may also be middot held during the adel development proceas

Diacusaion r

A table aUJUUrhing alta groundwater TCE levela annually for each well for the period 1910 through 1990 wa1 presented The table wa1 ~1ed on historical data bulls well as the current Supplementbull RI re1u1ts Re1ulta for wells allllpled aore thbulln once ln a year were 1veraged Selected d1t1 will be used for model calibration and validation

-l shy

-_ It waa agreed that OCE will not be modeled althouqh OCE could be modeled independently TCE and OCE have different densities and decay rates and can bull t be modeled as a total mass A aecond data table for OCE will be prepared

Sufficient data for transport model calibrationvalidation exiata The calibration and validation process waa discussed The model will be con1tructed on the bash of the 1983 TCE data set calibrated udng 1984 TCE data set and validated with the 1984-90 TCE data aets

The tran1port model interpolates actual values to determine TCE

I I

leveh between data pointbull vertically and horizontally

Changea in TCE levela re1ult from dilperlion and decay Total 1aa11 of TCE in the aodel will reuin conatant becau1e no decay will be lillulated

Sea1onal differencebull wouldnt be accounted for with thh llodel Model inputoutput h aeauaed for a eteady bulltate condition with c011pariaona aade on a annual inatead of aea1onal bJaia ~~ The llodel area 11 lar9er than the area IIOdeled by ERT Exhibita of thbull aodel 9rid bott011 of aquifer and infiltration rate eatiaatea were preeentect Boundary conditionbull and IIOdel reaolution were diiCUIIed

aeaulta of-the are recent Cheaterton anitoring will be included in the cheaical data bale

A printout of reaidual hydraulic heada will be aupplied to EPA with the adel re1ulta

Eatiaatea of detailed aaaa flux are very difficult becauae of the aurface watergroundwater interaction

Preliainary tlovpath adel re1ulta conahting of exhibitbull depicting hydraulic head contoura and groundwater flow velocity were pre1ented for the following acenarioa

1 No pullpin9 2 1990 puaping teet 3 Sta No 1 at 600 9pm Sta No 2 at 500 9pm 4 Sta No 1 at 600 9pm 5 Sta No 2 at 500 gpm

The next meeting waa tentatively aet for January 11 1991

The aeeting adjourned at approximately 330 pa

-2shy

UNITED STATES EN VIRONMENTAL PROTECTI ON AGENC Y REGION I

JFK Federa l Build1ng Boston MA 02203-2211

MEMORANDUM

DATE Deceoer 24 1910

SUBJ ~~ mer 1c e l ground-water ~oae i 1ng Grovela-o ~we ll s S1te Gr ove l an e t-14

FROM

TO

i rgte llicmiddot ~ltln t~ 11 st )f 1te ns reel to te aao~esec cy t1U~ - IF t nerc ar~ tny oestlcns t e J s l I O OE- r e e reO to ltayne ~acr al

vSG S f middot~1i - 5t5-t - ~

f ffVU I C c~ rgt-ec t ~ a t 11 i l st coe rlt S l gra l C S S~-middotsatmiddotmiddot )r

wmiddot~n N Lmiddot ~ middot s e~torts to oa t e r a umiddoter u-at we war t t he to oroouce a gJl J aef ens 1 o middotmiddot t~ mcmiddotoel

Q 1bull J- - o v oe wn t te~ SLa r y ot mae t g

1 i=lno v cbull maos 1al l a t sane s c a l e S 10middot~ 1 ng e +c ICmiddotI-111

nvomiddotmiddot a ~-bulll c co ~1 ou middot t1 1 1ty Ol StlOut on re~narce middotJI~tr ll 1 1 bull stat1f 1e c dnft anl t 1 l i at hr~ surfac e on t toM o f ao w1 f e r I where oecroc~ c t 1 I middot

s t rearr noles

l lr Ol de lap f middot g or e ~ 3ncw1r1g t t e d l StrlOJt l c n aro Tla 3 1 tl~~

of reslOJal water middotlE-ve ls for t ne following simu lati o s

measuPec I 3 - 16-9(bull l nor- oumoi ng cona i t 1ons vs t tnal calibrat 1o n va lues

measured I 3-90) p umo1ng conditton vs s 1mulatea values

4 1 Dtscuss cnter1a f o r sat 1sfac t o q ca l 1orat l On o f moo~ l

5) Simulate other oumo t ests

St a 0 - nemiddot bull 1 St COS~ru t e J

- 1~17

~ ta tmiddoton - ~lto r e ~ c c l t middotJ c t e J

s hou i o not oe modelec e xo 1a 1n wn y t

-_ It waa agreed that OCE will not be modeled althouqh OCE could be modeled independently TCE and OCE have different densities and decay rates and can bull t be modeled as a total mass A aecond data table for OCE will be prepared

Sufficient data for transport model calibrationvalidation exiata The calibration and validation process waa discussed The model will be con1tructed on the bash of the 1983 TCE data set calibrated udng 1984 TCE data set and validated with the 1984-90 TCE data aets

The tran1port model interpolates actual values to determine TCE

I I

leveh between data pointbull vertically and horizontally

Changea in TCE levela re1ult from dilperlion and decay Total 1aa11 of TCE in the aodel will reuin conatant becau1e no decay will be lillulated

Sea1onal differencebull wouldnt be accounted for with thh llodel Model inputoutput h aeauaed for a eteady bulltate condition with c011pariaona aade on a annual inatead of aea1onal bJaia ~~ The llodel area 11 lar9er than the area IIOdeled by ERT Exhibita of thbull aodel 9rid bott011 of aquifer and infiltration rate eatiaatea were preeentect Boundary conditionbull and IIOdel reaolution were diiCUIIed

aeaulta of-the are recent Cheaterton anitoring will be included in the cheaical data bale

A printout of reaidual hydraulic heada will be aupplied to EPA with the adel re1ulta

Eatiaatea of detailed aaaa flux are very difficult becauae of the aurface watergroundwater interaction

Preliainary tlovpath adel re1ulta conahting of exhibitbull depicting hydraulic head contoura and groundwater flow velocity were pre1ented for the following acenarioa

1 No pullpin9 2 1990 puaping teet 3 Sta No 1 at 600 9pm Sta No 2 at 500 9pm 4 Sta No 1 at 600 9pm 5 Sta No 2 at 500 gpm

The next meeting waa tentatively aet for January 11 1991

The aeeting adjourned at approximately 330 pa

-2shy

UNITED STATES EN VIRONMENTAL PROTECTI ON AGENC Y REGION I

JFK Federa l Build1ng Boston MA 02203-2211

MEMORANDUM

DATE Deceoer 24 1910

SUBJ ~~ mer 1c e l ground-water ~oae i 1ng Grovela-o ~we ll s S1te Gr ove l an e t-14

FROM

TO

i rgte llicmiddot ~ltln t~ 11 st )f 1te ns reel to te aao~esec cy t1U~ - IF t nerc ar~ tny oestlcns t e J s l I O OE- r e e reO to ltayne ~acr al

vSG S f middot~1i - 5t5-t - ~

f ffVU I C c~ rgt-ec t ~ a t 11 i l st coe rlt S l gra l C S S~-middotsatmiddotmiddot )r

wmiddot~n N Lmiddot ~ middot s e~torts to oa t e r a umiddoter u-at we war t t he to oroouce a gJl J aef ens 1 o middotmiddot t~ mcmiddotoel

Q 1bull J- - o v oe wn t te~ SLa r y ot mae t g

1 i=lno v cbull maos 1al l a t sane s c a l e S 10middot~ 1 ng e +c ICmiddotI-111

nvomiddotmiddot a ~-bulll c co ~1 ou middot t1 1 1ty Ol StlOut on re~narce middotJI~tr ll 1 1 bull stat1f 1e c dnft anl t 1 l i at hr~ surfac e on t toM o f ao w1 f e r I where oecroc~ c t 1 I middot

s t rearr noles

l lr Ol de lap f middot g or e ~ 3ncw1r1g t t e d l StrlOJt l c n aro Tla 3 1 tl~~

of reslOJal water middotlE-ve ls for t ne following simu lati o s

measuPec I 3 - 16-9(bull l nor- oumoi ng cona i t 1ons vs t tnal calibrat 1o n va lues

measured I 3-90) p umo1ng conditton vs s 1mulatea values

4 1 Dtscuss cnter1a f o r sat 1sfac t o q ca l 1orat l On o f moo~ l

5) Simulate other oumo t ests

St a 0 - nemiddot bull 1 St COS~ru t e J

- 1~17

~ ta tmiddoton - ~lto r e ~ c c l t middotJ c t e J

s hou i o not oe modelec e xo 1a 1n wn y t

UNITED STATES EN VIRONMENTAL PROTECTI ON AGENC Y REGION I

JFK Federa l Build1ng Boston MA 02203-2211

MEMORANDUM

DATE Deceoer 24 1910

SUBJ ~~ mer 1c e l ground-water ~oae i 1ng Grovela-o ~we ll s S1te Gr ove l an e t-14

FROM

TO

i rgte llicmiddot ~ltln t~ 11 st )f 1te ns reel to te aao~esec cy t1U~ - IF t nerc ar~ tny oestlcns t e J s l I O OE- r e e reO to ltayne ~acr al

vSG S f middot~1i - 5t5-t - ~

f ffVU I C c~ rgt-ec t ~ a t 11 i l st coe rlt S l gra l C S S~-middotsatmiddotmiddot )r

wmiddot~n N Lmiddot ~ middot s e~torts to oa t e r a umiddoter u-at we war t t he to oroouce a gJl J aef ens 1 o middotmiddot t~ mcmiddotoel

Q 1bull J- - o v oe wn t te~ SLa r y ot mae t g

1 i=lno v cbull maos 1al l a t sane s c a l e S 10middot~ 1 ng e +c ICmiddotI-111

nvomiddotmiddot a ~-bulll c co ~1 ou middot t1 1 1ty Ol StlOut on re~narce middotJI~tr ll 1 1 bull stat1f 1e c dnft anl t 1 l i at hr~ surfac e on t toM o f ao w1 f e r I where oecroc~ c t 1 I middot

s t rearr noles

l lr Ol de lap f middot g or e ~ 3ncw1r1g t t e d l StrlOJt l c n aro Tla 3 1 tl~~

of reslOJal water middotlE-ve ls for t ne following simu lati o s

measuPec I 3 - 16-9(bull l nor- oumoi ng cona i t 1ons vs t tnal calibrat 1o n va lues

measured I 3-90) p umo1ng conditton vs s 1mulatea values

4 1 Dtscuss cnter1a f o r sat 1sfac t o q ca l 1orat l On o f moo~ l

5) Simulate other oumo t ests

St a 0 - nemiddot bull 1 St COS~ru t e J

- 1~17

~ ta tmiddoton - ~lto r e ~ c c l t middotJ c t e J

s hou i o not oe modelec e xo 1a 1n wn y t

Jmiddot r ov 1ce wate - ~a middot a~e l3a bull r a 1 5 111 -LH l - s l te ls ~ 0

~ t Cgtmcsr-e e11sna rg e rr euroa ~ rerre t s Wlt Sl rula tmiddotons for 151~7 a na 119 bull c ump te ss

71 Creck orec1oitat1on recoras fo cl osest weatne stat1on a na use t hose cata

EJ Uescr1 oe re c arge est 1mat1on tecnn1que

lJ 0 1scuss nyor o middotI Of l C conaltlors to be s1mu bullated f o r long term transpo rt mode l 1ng

How w1 l l est 1mae s o f grcuro-wate r c iStarge (base f 1ow 1n straaSl be rroe

i~bull middot [ bull 1sc u~s w-- at ttbulle obullmiddots cel Ja s middotmiddot s ~ cr t r e tw o l a ye r D~ re t c l a ~ middot er s suf f l Clpound-lt shy

~c ( t 1 i yc1 _n st middot f~middot tr-e s= middote t - obull t r- e aobullnf e r c=toTl a s o middotmiddot c oce~

113t arbull t r a tO l ~~ o~- e rvmiddot e t tbull ~ s se middotl or middot 1~middot-middot t C t

co a l namiddoton oecoc bull ac t llbull ~

0 1 bull ~ gtw r e t ts a ~ ~ o middot ~ t r~~ - amp r t smiddot rrl-middotmiddot ~middotn rs of t LJIf~ t er ts

middot naos t l C ~ r oulo - middot-nmiddot tE- 1e ve 1 middot l OOgr3D bull1S