'5 J995

July 10 1995

VIA CERTIFIED MAILRETURN RECEIPT REQUESTFD

Mr Darrell J SommerhauserU S ERA Region VII726 Minnesota AvenueKansas City KS 66101

roBroikOth.01

At,)

SUBJECT Additional Response Action Draft Downgradient Monitoring Well Installation Work PlanColorado Avenue Subsite Hastings Ground Water Contamination SiteU S ERA Unilateral Administrative Order Docket Number VII 93 F 0019

Dear Mr Sommerhauser

ERA s letter of May 12 1995 (Sommerhauser to Muzik) responded to but gave no consideration toDravo s letter of April 13 1995 which requested that the installation of the downgradient monitoring wellsbe deferred until the groundwater recovery and treatment system is in place ERA s letter indicated thatrather than dealing with Dravo s request ERA would undertake the work themselves and bill theRespondents for the work

By separate correspondence also dated May 12 1995 ERA (Asher to Brodnik and Serrano) advisedthe other Colorado Site Respondents of ERA s action noted above and stated that ERA construes Dravo swntten response and failure to submit a work plan for the additional response actions as a refusal toperform the additional response actions The ERA letter then went on to remind the respondents of thecivil penalties possible for failure to comply with ERA s Orders

Dravo has not refused to perform the work We submitted a very reasonable request to perform workat the same time when the treatment system is installed Since ERA (1) refuses to consider our request(2) has threatened to perform the work and bill Respondents and (3) has threatened civil penalties thatwould far exceed the cost of the work Dravo has little choice but to proceed with the unnecessary work

Accordingly Enclosure (1) Downgradient Monitoring Well Work Installation Plan dated July 1995 issubmitted for ERA approval

Sincerely

enclosure (1)

cc Martyn Brodnik EsqLawrence A Demase EsqJohn Fulton ENSR w/enclosureGlenn Serrano Esq

Charles J MuzikProject Coordinator

2014043

CAR3150

Colorado Avenue SubsiteHastings GroundwaterContamination Superfund SiteHastings, Nebraska

Downgradient Monitoring WellInstallation Work Plan

Prepared for Dravo Corporationby ENSR Consulting and Engineering

July 1995

Document Number 2340-003 142

CAR3151

BNGX

CONTENTS

1 0 INTRODUCTION 1 11 1 Purpose 1 1

2.0 WELL INSTALLATION AND SAMPLING PROGRAM 212 1 Proposed Well Locations 2 12.2 Monrtonng Well Installation Procedures and Methodologies 2-6

30 SCHEDULE 31

APPENDICES

R. \HEPORTS\2340O03 142

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LIST OF TABLES

Procedures and Methodologies 2 7

H \REPORTS\2340003 142

UST OF FIGURES

1 Proposed Monitoring Well Locations 2 32 Proposed Well Construction Details for BW 9D 2-43 Proposed Well Construction Details for BW 10 and BW 11 254 Proposed Downgradient Monitoring Well Installation Schedule 3 2

R.\REPORTS\2340003 142

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1 0 INTRODUCTION

The Downgradient Monitoring Well installation Work Ran (Work Plan) is prepared on behalf ofthe Dravo Corporation (Dravo) and fulfills paragraph 50 (d) (f) of the March 1993 UnilateralAdministrative Order (UAO) Docket No VII 93 F0019 Statement of Work (SOW) and the U SEnvironmental Protection Agency s (EPA s) March 22 and May 12,1995 letters The UAO whichwas issued by the EPA, required that a Groundwater Remedial Design/Remedial Action (RD/RA)Program for the Colorado Avenue Subsrte (Subsite) Hastings Nebraska be developed

11 Purpose

Data generated from the downgradtent monitoring wells will be used to 1) assess the effects ofmass removal and containment of volatile organic compounds (VOCs) in the groundwaterbeneath the Subsite and 2) evaluate the potential impacts of VOCs on groundwater from othersource areas This Work Plan addresses the following

• a schedule for installing and sampling the downgradient monitoring wells

• proposed well locations and

• methods and procedures associated with monitoring well installation

R \RETORTS\234O003 142 1 1

CAR3J55

2 0 WELL INSTALLATION AND SAMPLING PROGRAM

The well installation and sampling program consists of the following

• Installing three downgradient monrtonng wells (BW 9D BW 10 and BW 11) and

• Collecting groundwater samples from wells BW 9D BW 10 and BW 11 and two existingwells (MW 7 and MW 24)

The following sections detail monitoring well locations and well installation procedures andmethodologies

2.1 Proposed Well Locations

The following section provides a basis for selecting the proposed monrtonng well locationsillustrated in Rgure 1

BW9D Proposed monrtonng well BW 9D which will be screened from approximately 165 feetto 200 feet below the ground surface will be installed adjacent to MW 7 Well MW 7 is locatedeast of the Thomson Oil Company and was installed by the State of Nebraska as part of theState s response to a leaking underground storage tank

BW 90 will act as the deep monrtonng well complement to MW 7 Data generated from BW 9Dwill be used to assess the extent of VOC migration east of Bm Street and to assist in delineatingthe 290 /yg/l isoconcentration contour which will be used to establish the area of treatmentdescribed in the SOW page 2 paragraph 2

BW 10 and BW 11 Proposed monrtonng wells BW 10 and BW 11 which will be screened fromapproximately 120 feet to 200 feet below the ground surface will be installed to evaluate thetransport of VOCs associated with other potential source areas east of Bm Street as well asprovide groundwater chemistry and elevation data to fulfill the requirement for downgradientcompliance monrtonng The well design utilizing an extended well screen was previouslyapproved by the U S EPA in their letter dated October 27 1993

The monrtonng wells which are referred to as downgradient compliance wells are located in agenerally north to south line and are aligned perpendicular to the direction of groundwater flow

FL\flEPO«TS\23*0003 1*2 21

CAR3156

Both are located approximately 800 feet east of Elm Street and are being installed todemonstrate the long term effectiveness of the interim remedy

Monitoring well construction details for wells BW 9D and BW 10/BW 11 are presented as Rgures2 and 3 respectively

R.\BEPORTS\23*0003 142 22

C'ARjl57

•II

0 500 1000 2000SCALE IN FEET

BOB

MN-24

FIGURE 1

BW-9D

UW-24

PROPOPSED DOWNGRADIENT UONfTORING WELL

EXISTING DOWNGRADIENT MONITORING WELL

SOimCC. THIS FIGURE WAS PREPARED AND MOOmCD FROM A FIGURE BYMK ENVIRONMENTAL SENT VIA TAX OATH) OCTOBER 16 1882

ENSR CONSULTING AND ENGINEERING

PROPOSED DOWNGRADIENTMONITORING WELL LOCATIONS

COLORADO AVENUE SUBSITEHASTINGS NEBRASKA

MOPJWF

Dote. 6/7/957/7/95

ProiactNumtMr2340

i- h_- 003181

CARS ] 58

TOP OF PVCWELL CASING

0 —

155 —

160 —165 —

200 —

LOCKED CAP

CONCRETE PAD

GROUND SURFACETOP OF GROUT

PROTECTIVEOUTER CASING

10-INCH DIAMETERBOREHOLE

4-INCH DIAMETERPVC WELL CASING

STATIC WATER LEVEL

VOLCLAY GROUT OR BENTONITE

TOP OF SEALBENTONITE PELLETS

OF FILTER PACKTOP OF WELL SCREEN

4-INCH DIAMETERSTAINLESS STEEL OR PVCWELL SCREEN

CENTRAUZERS

SIUCA SANDFILTER PACK

BOTTOM OFWELL SCREEN

BOTTOM OF BOREHOLE

FIGURE 2BW-9D WELL CONSTRUCTION DETAIL

COLORADO AVENUE SUBSITEHASTINGS GROUNDWATER CONTAMINATION SFTE

_ _— — — HASTINGS, NEBRASKAENSR CONSULTING AND ENGINEERING ____=_______..=___- __

2340-003\234O34o

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TOP OF PVCWELL CASING

0 —

• 105 -

110 —115 -

200 —

205 —

LOCKED CAP

CONCRETE PAD

GROUND SURFACE

TOP OF GROUT

PROTECTIVEOUTER CASING

10-INCH DIAMETERBOREHOLE

4-INCH DIAMETERPVC WELL CASING

STATIC WATER LEVEL

VOLCLAY GROUT OR BENTONITE

TOP OF SEALBENTONITE PELLETS

TOP OF FILTER PACKTOP OF WELL SCREEN

4-INCH DIAMETERSTAINLESS STEEL OR PVCWELL SCREEN

CENTRAUZERS

SILICA SANDFILTER PACK

BOTTOM OFWELL SCREEN

BOTTOM OF BOREHOLE

FIGURE 3BW-10/BW-11 WELL CONSTRUCTION DETAIL

COLORADO AVENUE SUBSITEHASTINGS GROUNDWATER CONTAMINATION SITE

HASTINGS, NEBRASKA.NSR CONSULTING AND ENGINEERING -

CAR3160

2.2 Monitoring Well Installation Procedures and Methodologies

In general the procedures and methodologies outlined in the Sampling and Analysis Plan (SAP)which was approved in December 1993 will be used as the guidance document for thisinvestigation Modifications to the procedures specified in the SAP are presented below

• BW 90 BW 10 and BW 11 will be constructed of 4-inch diameter PVC nser and wellscreen Each well will be installed approximately to the top of clay (approximately 200feet) using the procedures outlined in the SAP

• The well screen associated with BW 9D will be installed so that the bottom of the screenextends from approximately the top of day to approximately 165 feet below the groundsurface (See Rgure 2)

• The well screen associated with BW 10 and BW 11 will be installed so that the bottomof the screen extends from approximately the top of clay to approximately seven feetabove the static water table surface (approximately 120 feet below the ground surfaceSee Rgure 3)

• Groundwater sampling will be conducted using a 5 foot interval packer system to allowfor discrete sampling Stepwise procedures for utilizing the packer system are presentedin Appendix A

Table 1 lists the procedures and methodologies which will be utilized during the investigation

R.\REPORTS\2340003 142 26

CAR.,/6;

TABLE 1

Procedures and Methodologies

*WiDrilling Procedures

Sofl Sampling Procedures

Total Organic VoJatBe Screening Procedures

Health & Safety Air Monitoring

Monitoring WeU Installation Procedures

Monitoring Well Development Procedures

Groundwater Elevation Data

Well Labeling

Groundwater Quality Sampling

QA/QC Samples

Field Equipment Calibration

Decontamination Procedures

Sample Handling Requirements

Documentation

Sampling Packing & Shipping

x?"' ̂ *̂?»!$ppa8pf*2$eciHwMolWlBp*̂

3.1

3.2

3,3

34

3.8

38

381

38.2

383

39

310

40

50

53

54

**" f*ge32

32

37

3-7

3-6

311

312

313

313

315

3 16

4-1

51

5-3

5-4

'Dated July 1993 and approved in December 1993

R \TABLES\2J40003 TA1

CARj 162

30 SCHEDULE

The schedule for completing the investigation is presented in Figure 4 The scheduled durationof the entire project is approximately five months

R. \RBWTS\2M0003 142 31

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FIGURE 4PROPOSED DOWNGRADIENT MONITORING WELL INSTALLATION SCHEDULE

COLORADO AVENUE SUBSITE HASTINGS NEBRASKA

Task Name Start Date Duration End Date

^^L-HH

' ^J•*"t]

S bmrt Downgradient Monitoring Well Installation Work Plan 7/10/95 Od 7/10/95

EPA Review a d Appr al 7/10/95 21 OOd 7/30/95

S to Ac e s Ag eements 7/31/95 14 OOd 8/13/95

S bcontractor Bid and Selection 7/31/95 21 OOd8/20/95

M bilization 8/21/95 5 OOd8/25/95

Drill and Install Wells 8/26/95 14 OOd 9/9/95Well Development 8/10/95 3 OOd8/12/95

Soil Disposition Sampling 9/10/95 100d 8/10/95Receive Laboratory Results Associated with Soil Disposal 9/11/95 14 OOd 9/24/95Disposal of Soil Cuttings 9/25/95 30 OOd 10/24/95WellS mpl g 10/1/95 5 OOd10S/95

Survey Wells 9/10/95 2 OOd9/11/95Rec tve L boratory Results 10/6/95 20 OOd 10/25/95

D ta Validation 10/26/95 10 OOd 11M/95

P epare Report 11/5/95 25 OOd 12/1/95

o

o\

Printed 7/10/95Page 1

APPENDIX A

STEPWISE PROCEDURE FOR USING THEINTERVAL PACKER SYSTEM

IV

FINAL SAMPLING AND ANALYSIS PLAN

FOR MARCH 1*91 QUARTERLY SAMPLING

AT THE

HASTINGS GROUND WATER CONTAMINATION SITE

Hastings, Nebraska

March 14, 1991

Work Assignment No 08 7LS2

Prepared by

MK Environmental Services1120 Lincoln Street, Suite 1200

Denver, Colorado 80203

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rt

IIII

APPENDIX A-I

STANDARD OPERATING PROCEDURES

JJJ

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II

III

m. If multiple nnervals are to be sampled withm a single stacked dedicatedbladder pump well, switch to new sampling ports and repeat steps e throughL Repeat for »fh additional sampling interval,3

]]]J

and field duplicate samples may be performed to ensure data qualityJ Proper packer inflation is necessary to ""™™"* the intake of formation water from depth

intervals other than that of interest. The packer must be inflated such that the rubber1 gaskets press firmly against the monitor well casing Incomplete inflation may allowJ leakage of borehole water from above or below the packer into the sampling interval1 Borehole packers cannot prevent formation water from traveling outside the boreholeJ through the filter pack and entering the "packed off interval."

] 3 4 J Interval Sampling PnmpDuring the ground water sampling program, every effort will be made to preserve theintegrity of samples and to avoid any contamination of samples from equipment usedbetween weDs. Insuring sample integrity wJD be accomplished by utilizing pumping, bailing,and sampling techniques which nmnTnw disturbance of water being sampled in order toprevent volatilization of organics. Rigorous decontamination procedures wfll be followedto prevent cross contaminanon from other wells or outside sources. Samples may beanalyzed for volatile organics, EDB, semi-volatile organics, metals, major ions, and

Analyses of quality control samples such as xmsate samples, trrp (travel) blanks,

As target depths maease the effective force on the packers from ambient formation waterincreases Accordingly the following formula should be employed to define the inflationpressures which must be obtained to properly inflate the packers

Inflation pressure = 433 x H -t 10 psi

where

I433 = pounds per square inch (psi) of water per foot

I H = distance from water table to midpoint of the packer in feet• 10 pa = Safety Factor

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JUN-e6-l995 16 06 913 551 7145 9T/" p 04

A second qualitative check should be performed 10 insure proper packer inflation.Occasionally, tug on the safety cable to insure there is significant faction between theborehole wan and the packers and monitor the packer inflation pressure with a pressuregage

The procedures that wfll be used to collect ground water samples with the intervalsampling bladder pump include the following steps

a. Check well for above-ground damage.b Remove the well capc. Take and record OVA readings for background, at the well head and in the

breathing zone. If necessary, make appropriate adjustments to level of healthand safety protection, according to the Site-Specific Health and Safety Plan.

d, Pnor to sampling, measure and record from the top of the well, inner casingdiameter (m\ depth to water (ft), total depth of well The height (AH) ofwater column to be purged for each casing volume is the distance betweenpackers, five feet Calculate the total volume of water to be purged fromthe well (approximately 3 packer interval volumes) using the followingformula.

V = 0.0408 x AH x D1

where V » one well volume (gals)0 0408 gal/m'-ft = conversion factor to gallonsAH = effective height of the water column (ft)

AH = H h, where H = Total depth of well (ft) and h= Depth to water (ft) in well

D - diameter of well casing (in)and 3 x V = iota! purge volume (gals)

e. Lower interval sampler to deepest target interval Depth intervals aremeasured as depth below ground surface. Inflate packers, record tune andstart pump Take OVA, pH, temperature, and conductivity readings on purgewater

A26

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JUN-06-1995 18 06 913 551 7145 ST/" P 05

•

J

f. Purge the well by removing the equivalent of three sampling interval wellvolumes of water After each well volume is removed, take a grab samplefor temperature, pH, specific conductivity, and OVA measurements. Theexact amount of purging will be determined m the field on the basis of

. geological and/or hydrological conditions and on wen construction detail (seeJ Section 32 for details) Water purged from the wells, except grab sample

water, will be passed through a carbon filtration unit prior to discharging to1 the ground surface Rinse pH and EC meters with deaomzed water after each

useg Reduce pumping rate to a level that wiD immmrt* volatilization,h. Fill the VOA vials such that a convex meniscus is formed on the neck of the

vial and carefully cap the bottle. Tip the bottle upside down and inspect forJ air bubbles. Should noticeable air bubbles appear, repeat the process until

an an* free sample is obtained. If an air-free sample is not achieved in twoJ tnes, dump the vial out and start procedure over with fresh formation water

Sample for all other appropriate anarytes after VOAs and EDB are collected.1 i. Deflate packers. Raise interval sampler to second deepest sampling interval.•J Inflate packers, record time and start pomp Take OVA, pH, temperature,

and conductivity readings on purge water Repeat steps f. through h. for theJ second interval

j Deflate packers. Raise interval samphng to shallowest sampling intervalInflate packers, record time and start pump Take OVA, pH, temperature,and conductivity readings on purge water Repeat steps i through h. for the

1 third interval to be sampled and any additiririai intervals.J k. Carefully log and package aD sample bottles m their respective coolers, add

ice and packaging material as necessary, and seal for shipment.L Deflate packers and remove the interval sampler from the well

Decontaminate by applying high temperature, high-pressure water spray to allJ portions of the yymplmg ^pflpipgnT. Submerge pump intake ports in

3

water and pump three to five gallons of distilled water through pump andi tubing to remove remnant formation water Decontaminate gloves, boots andJ clothing, when appropriate, in a

m. Lock the wells (if appropriate)

m. A<l27

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I\

n. Dispose of expendable materials in a plastic bag and label bags as samplingwaste,

o The following information will be recorded on the sampling log form

• Well number• Sample numberOO• Total depth of well, water level before purging, top and bottom

of sampling interval (if appropriate) casing diameter• Purge volume• Any visible well damage• pH, temperature, conductivity and OVA readings

Time begin purge• Time end purge• Sample ume(s) and date(s)• Well purging and sampling technique• Type of sample (ground water duplicate, nnsate tnp blank,

other)• Analysis requested• Samplers' signatures• Other notes and information, as required

344 BailerDuring the ground water sampling program, every effort will be made to preserve theintegnty of samples and to avoid any contamination of samples from equipment usedbetween wells. Insuring sample integrity will be accomplished by utflinng pumping, bailing,and sampling techniques which rmmTnw. disturbance of water being sampled m order toprevent volatilization of organic*. Rigorous decontamination procedures will be followedto prevent cross contamination from other wells or outside sources. Samples may beanalyzed for volatile organics, semi volatile organics EDB n^tai^ major ions andalkalinity Analyses of quality control samples such as nnsate samples tnp (travel) blanks,and field duplicate samples may be performed to ensure data quality

A-28ximm

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