NCD991278953_19960522_National Starch & Chemical Corp._FRBCERCLA RA_Comments on 1996 Reply to Comments on the RD RA Work Plan OU-3 and OU-4-OCR

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
BRAC UNIT ID:404-347-1735 MAY 22'96 9:10 No.001 P.01 VVl!t,JNAI... f'Ulll,.I W \l•IIU}
'" FAX TRANSMITTAL .,,,,.,.,,--2....
~
'Grn~RAL !.ERViCES ADMINISTHA I ION I
May 22, 1996
·,: " •'•""
4WMD·NSRB .DR~liJj
Dr. Abu M. z. Alam
National Starch & Chemical Company
10 Finderne Avenue
P.O. Box 6500
Bridgewater, NJ 08807-0500
SUBJ: Comments on National Starch & Chemical Company March 28,
1996 Raply to Comments on the Draft Remedial Design/
Remedial Action Work Plan for Operable Unit #3 and
Operable Unit #4 at the National Starch & Chemical Company
Superfund Site
Dear Dr. Alam:
Below arc the Agency's comment~/concerns on National starch
& Chemical Company March 28, 1996 corrc1;1pondences. These
comments/concerno need to be addressed in the revised Remedial
Design/Remedial Action Work Plans for Operable Units #3 and 114.
If you disagree, please call so that we can discuss your
concerns·. '
'I'he Agency would like to receive the final version of these
documents by Friday, June 2J, 1996.
Comments/concerns with regard to NSCC March 2R, 1996
Response to NCIJEHNR Comments on NSCC Response to Jant.1ary 18
Comment~ on Remedial Design/Remedial Action Work Plan for
Operable Unit #3, at the Na ti_onal Starch & Chemical Company
Superfund S.ite. : ·"'
The December 1995 araft work Plan states that the bedrock
extraction wells'will be drilled to a depth of 200 foot below
surface. As discussed and agreed upon during our March 26
conference c_all,' two of these wells will be cored to depth.
Groundwater samples will be collected from these two wells via
packers (every HJ feet or sol to define the vertical depth of
groundwater contamination in the bedrock zone. If the oorc,s at
200 feet depth show fractures, the coring is to continue until
competent bedrock is encountered.
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
BRAC. UN IT .ID:404-347-1735 MAY 22'96 9:10 No.001 P.02
' ' ; .
' This information will be used to determine if the existing
bedrock wells are at sufficient depth to determine the aerial
extent of groundwater contamination in the bedrock zone and
whether or not the existing bedrock monitoring wells arc at
sufficient depth to monitor the bedrock extraction systems in the
lagoon area and Arca 2. This approach needs to delineated in the
revised Work Plan.
Comments/concerns with regard to NSCC March 28, 1996
Response to USEPA Comments (3/18/96) on Remedial Design/Remedial
Action Work Plan'. for Natur.il Degradation Trea tabili ty Study for
Operable Unit #4 at the Natjonal Starch & Chemical Company
superfunei Site.
1. Page 3, Item 2., third paragraph, second sentence: Change
this sentence to read, "· .. on a quarterly basis for 1,2-DCA
andiJEor:,:1-,,JEDCA degradation by ·producLs such as ... ".
2, Page 3, Item 2., fourth paragraph: The installation and
sampling procedures for the soil gas monitoring wells need to
be incorporated in the revised documents.
3. Page 3, Item 3: Are soil gas samples to be collected from
two separate depths at every location (the four Soil Plots
and the four. Soil Gas Mani taring locations as discussed in
Item 2 at the top of Page 3)? This component needs to be
clarified.
If you have: any questions, please c<1ll me at (404) 347-77!H,
x:·2053.
sincerely yours,
Jon K. Bornholm
Remedial ?reject Manager
Enclosure
cc: David Lown, ·NCPEHNR
1·
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION4
3◄5 COURTLAND STREET. N.E.
AT"WJ~ q_e5'~G't91~:i,6S
VIA FACSIMILE
RECEIVED
MAY 201996
SUPERFUNO SECTION
4WMD-NSRB
Mr. David J. Lown
.North Carolina Department of Environment, Health
and Natural Resources/Superfund Section
Suite 150
401 Oberlin Road
Raleigh, NC 27605
SUBJ: Request to Review Two March 28, 1996 Response to Comments on OU
#3 Remedial Design/Remedial Action Work Plan and OU #4 Natural
Degradation.Treatability Study work Plan for the National Starch
& Chemical Company Superfund Site
Dear Mr. Lown:
I have facsimiled for your review and the State's file the
referenced document submitted to the Agency on March 18, 1996. Please
review these documents. If you have any comments, please submit them to
me by Wednesday, May 29, 1996. Thank you for your efforts. I will send
you hard copies of these documents as well.
If you have any questions, I can be reached at [phone], x-
2053.
Sincerely yours,
jlbPJc--
Jon K. Bornholm
Remedial Project Manager
Enclosures
1.
2.
March 28, 1996 Response to NCDEHNR Comments on NSCC Response to
January 18 Comments on Remedial Design/Remedial Action Work Plan for
OU #3 at National Starch & Chemical Company Superfund Site.
March 28, 1996 Response to USEPA Comments (3/18/96) on Remedial
Design/Remedial Action Work Plan for Natural Degradation
Treatability Study for OU #4 at National Starch & Chemical Company
Superfund Site.
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
• CONFIRMATION OF FAX SENT 3/28/96
{l[:~tional Sta,ch and Chem/ca/Company
SAFETY AND ENVIRONMENTAL AFFAIRS -BRIDGEWATER, NJ FAX LEA DER SHEET
' To: JON K. BORNHOLM Date: March 28, 1996
USEP A REGION IV, ATLANTA
Fax No.: 404-347-1695
,from: Abu Alam
Tel: [phone]; Fax: [phone]
Pages: 7 (including this c:over sheet)
Subject: Response to USEPA Comments of 3/18/96
Attached please find the Responses to USEPA's comments of March 18, 1996 on
NSCC's January 16 response on earlier ( 11/22/96) comments on the Remedial
Design/Remedial Action Work Plan for the Operable Unit 4 (OU4) at the Cedar
Springs Road Plant site in Salisbury, North Carolina. We are also sending a hard copy
to you by maiL: Thanks for your assistance in this matter. Regards,
Abu Alam
C:\rROJECTS\SALSBRY\FAXBRNH4.AA
.°i.1::JlS u u ...... 1 .. ._..,
U: ~ --JU:CllON IV
A '!';.AN'f A, GA
The information contained in this facsimile message is confidential and intended only for the use of the individual or entity named above. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this coffimunication is strictly prohibited. If you have received this communication in error, please immediately notify us by telephone, so that we may arrange for the return of the original m~ssage to us. Thank you.
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
fBJ:!.tional Starch and Che~lca/ Company
10 Finderne Avenue
P.O. Box 6500
Bridgewater, New Jersey 08807-0500
908-685-5000
Cable Address: NASPROD,BAJDGEWATERNEWJEASEY
Writer's Direct Dial Number:
Fax Number:
Mr. Jon Bomhqlm
Remedial Project Manager
United States Environmental Protection Agency
Region IV :
345 Courtland Street, N.E.,
Atlanta, Georgia 30365
March 28, I 995
Subject: Response to USEP A comments (3/18/96) on
Remedial Design/Remedial Action Work Plan for
Natural Degradation Treatability Study for Operable Unit 4
at National Starch and Chemical Company's Cedar Springs
Road Plant, Site, Salisbury, North Carolina
Dear Mr. Bornholm:
Attached please find NSCC's response to USEPA's March 18 comments. USEPA provided
these comments after review of NSCC's January 16 response to USEPA's November 22
comments an the Natural Degradation Treatability Study Work Plan for the fourth Operable Unit
(OU4) al the National Starc,h and Chemical Company's Cedar Springs Road Plant site in North
Carolina. Altogether there are five pages of comments and responses. As in the case of
responses to OU3 comments NSCC assumes that USEPA will transmit these responses to the
NCDEHNR. We will wait until we hear from you and the NCDEHNR before we revise and
finalize the Natural Degradation Treatability Study Work Plan. Please feel free to call me if
there are any questions.
Very Truly Yours,
aiu/J'Yl-~ae,..____
Abu M. Z. Alam, s90. P.J;'..
Director, Environmental Projects
CC: D. Cregar, NSCC w/o Response
M. Ford, NSCC
C:\l'ROJECTS\SALS8RY\OU4TLTR3.AA
A. Samson, NSCC
R. Paradowski, NSCC
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Responses to USEPA's Comments (03/18/96) on the
Remedial Design/Remedial Action Work Plan
for the Fourth Operable Unit (OU4)
: National Starch & Chemical Company
Cedar Springs Road Plant, North Carolina
' A. Work Plan Comments
The Agency continues to question NSCC's approach with regard to constructing single plots for
each of the parameters to be evaluated and the location selection of the plots. The Agency
believes that it is necessary to duplicate (at a minimum) each plot as well as have randomized
location of the plots. The Agency's rationale for taking these positions is provided in the
following comments:
Comment No. 1
NSCC argues that their original approach of using a single plot to evaluate the effectiveness of
each treatment is adequate to meet the objectives of the study. The four plots proposed are: no
treatment, treatment with moisture, treatment with moisture and nutrients, and no treatment in
an uncontaminated area. lfthe objectives of this study are (1) to measure the rate of natural
degradation of 1,2-dichloroethane (DCA) with known confidence, and (2) to determine with
known level of confidence that the treatments provide ( or do not provide) a greater rate of
degradation, then the approach proposed by NSCC is insufficient.
For a specific treatment, in order to know the rate of degradation and the associated error of it's
value (i.e., error bars), replicate plots must be operated. In other words, replicate plots allow the
calculation of the rate +/-error where the magnitude of the error indicates the confidence of the
computed rate. Thus, if a measured degradation rate implies that the site would be clean in 20
years due to natural degradation, insufficient data would be collected to specify if the rate is 20
+!-5 years or 20 +/-19 years. In this example, the error will assist the Agency in determining
the feasibility of the proposed treatment.
The error in the rate is also required to compare the effectiveness of the treatments. By
operating replicate plots, sufficient data will be generated to state with known confidence that a
particular treatment approach provides a higher rate relative to others, or that it does not ( e.g.,
Treatment, is superior to Treatment2 with 80% confidence). Without replicate plots, this will
not be attainable.
C:\PROJECTS\SALS8RY\OU4RESP2.AA
If
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
\
Response to Comment No. l
The Natural Degradation Treatability Study is required by the Record of Decision (ROD) for
Operable Unit 4 (OU4). The Statement of Work accompanying the Unilateral Administrative
Order for Remedial Design/Remedial Action at OU3 and OU4 stated the following five
objectives for the Natural Degradation Treatability Study:
1.
2.
3.
4.
Determine ifthe natural degradation of site contaminants is occurring in the
saprolite;
Determine whether natural degradation can be enhanced through the
addition of nutrients to the soil;
Determine where in the subsurface degradation is occurring;
Determine at what rate the natural degradation is proceeding; and
5. Estimate a time frame when the Performance Standards via natural
degradation will be attained.
As discussed during the March 26 telephone conference with the USEP A and the NCDEHNR,
NSCC and its consultant Dr. David Kosson of the Rutgers University has reviewed USEPA's
comments in the light of the five objectives of the Natural Degradation Treatability Study listed
above. To achieve the above five objectives in an efficient and cost-effective manner, NSCC
proposes the following modifications to the Remedial Design/Remedial Action Work Plan for
OU4 submitted during October 1995.
1. Initially NSCC will conduct the Natural Degradation Treatability Study
using the four Soil Plots as originally proposed. The purpose of this initial
phase is to determine:
(a) If natural degradation of 1,2-DCA is occurring in the saprolite;
(b) Whether natural degradation of 1,2-DCA can be enhanced by
addition of moisture or addition of moisture and nutrients; and
(c) Which of the three treatment methods provides the maximum
· degradation of 1,2-DCA.
NSCC believes that ;the results of this initial phase of the study will identify the
treatment method that produces the best degradation rate and will also give initial
estimates of the degradation rates for the three treatment methods.
C:\PROJECTS\SALSBRY\OU4RESP2.AA 2
I
D
I
I
I
I
I
I
I
I
I
I
I
I
I
I
\
2.
3.
4.
During the initial phase of the Natural Degradation Treatability Study
· NSCC will 'also install four Soil Gas Monitoring Wells in the unsaturated
saprolite zqne. Two of these four Soil Gas Monitoring Wells will be located
in the contaminated soils near the Lagoon Area and the other two Soil Gas
Monitoring Wells will be located in the contaminated soils under the
pavement in Area 2.
During installation of each Soil Gas Monitoring Well soil samples will be
collected and analyzed to establish initial concentrations of 1,2-DCA and
other organic contaminants.
The proposed Soil Gas Monitoring Wells will be located at random. Soil gas
from these wells will be monitored on a quarterly basis for 1,2-DCA
degradation by-products such as Chloroethane, ethane, ethene and vinyl
chloride. Data from these four Soil Gas Monitoring Wells will then be used
to determine whether 1,2-DCA is naturally degrading at other contaminated
locations at ,this site.
Results of soil gas monitoring in these four Soil Gas Monitoring Wells will
also be compared and correlated with the results of soil gas monitoring in the
four proposed Soil Plots in Area 2.
In the initial phase NSCC will collect and analyze soil gas samples from two
separate depths (one screened at 2-4 ft. and the other screened. at 5-7 ft.)
using nested vapor sampling wells and 0.25 inch diameter stainless steel
tubing. These measurements will provide answer to where in the soil
1, 2-DCA de_gradation is taking place and will also provide concentration
gradients in .the soil gas.
Upon establishment of the treatment method that gave the best degradation
rate for 1,2-DCA during the initial phase ( estimated to be about one year),
NSCC will select this treatment method for replication at other locations
during the second phase. Replication will be conducted at three other
randomly selected Soil Plots to establish a reliable and statistically valid
degradation :rate for 1,2-DCA.
NSCC believes that the proposed Soil Plot with addition of moisture and
nutrients wiH give the highest degradation rate. Whichever treatment
method (Soil. Plot) gives the best degradation rate during the initial phase,
NSCC will continue to operate that Soil Plot during the second phase. The
other three Soil Plots will be relocated during the second phase at three
randomly selected locations within the contaminated soil.
C:\PROJECTS\SALSBRY\OU4RESP2.AA 1 3
R
D
I
I
I
I
I
I
I
I
I
I
I
I
I
I
5.
6.
Monitoring results from all four Soil Plots duplicating the same treatment
method wiil then be used to determine statistically valid 1,2-DCA
degradation ratc(s) and to estimate the time required to clean up the site.
Before starting the initial phase of the field study NSCC will collect two soil
samples from the contaminated area. These soil samples will be used for
conducting laboratory studies and screening for biodegradation. These
laboratory ·studies will answer the following questions:
a. Are ;bacteria capable of biodegrading 1,2-DCA in soil at the site?
b. Which conditions most favor biodegradation of 1,2-DCA at the site?
c. What additions (moisture, nutrients, pH control agent, etc.) will
enhance the biodegradation rate most?
I d. What arc the specific biodegradation rates under controlled
conditions in the laboratory?
The answer to these questions will assist in conducting the field
biodegradation study, and collection and interpretation of data.
Before starting the initial phase of the field study NSCC will also collect soil
samples from the contaminated area to establish partitioning of 1,2-DCA
between the· soil water and solid phases, and between soil vapor and solid
phases. Results of 1,2-DCA partitioning will assist in the interpretation of
the soil gas inonitoring data including the mass balance of the degradation
products of 1,2-DCA such as Chloroethane, ethane, ethene, and vinyl
chloride.
Comment No. 2
NSCC argues that because values of environmental parameters are often correlated to distance,
randomization of the location plots is a poor approach. The Agency believes the opposite to be true. Because these values may be correlated with distance , i.e., the values may be a function
of space, not randomly distributed, the location of the plots must be randomized to eliminate the
spatial bias.
Response to Comment No.·2
NSCC respectfully disagrees with the Agency. NSCC had provided enough information
indicating that randomizat_ion brings in far more uncertainties in the determination of
C:\l'ROJECTS\SALSBRY\OU4RESP2.AA 4
I
R
I
I
I
I
I
I
I
I
I
I
I
. .
degradation rates. However, rather than continue to argue the merits of specific versus
random selection of Soil mots and delay the implementation of this project, NSCC
proposes to install three Soil Plots at random locations during the second phase (about
1 year after the initial phase) of the Natural Degradation Treatability Study after
establishment of the best treatment method and determination of preliminary estimates of
the 1,2-DCA degradation rates from the four Soil Plots installed during the initial phase.
C:\l'ROJECTS\SALSBRY\OU4RESP2.AA 5
I
R
I
I
I
I
I
I
I
I
I
I
I
I
I
I
, I
' CONFIRMATION OF FAX SENT 3/28/96
{N;ational Starch and Chemical Company
SAFETY AND ENVIRONMENTAL AFFAIRS-BRIDGEWATER, NJ
\
FAX LEA DER SHEET
To:· JON K. BORNHOLM Date: March 28, 1996
USEP A REGION IV, ATLANTA
Fax No.: 404-347-1695
From: Abu Alam
Tel: [phone]; Fax: [phone]
Pages: 18 (including this:cover sheet)
Subject: Response to NCDEHNR Comments of 3/13/96
Attached pleas~ find the Responses to NCDEHNR's comments of March 13, 1996 on
NSCC's Febru~ry 22 response on earlier( 1/18/96) comments on the Remedial
Design/Remedial Action Work Plan for the Operable Unit 3 at the Cedar Springs
Road plant site in Salisbury, North Carolina. We are also sending a hard copy to you
by mail. Thanks for your assistance in this matter. Regards,
Abu Alam
C:\PROJECTS\SALSBRY\FAXBRNH3.AA
The information contained in this facsimile message is confidential and intended only for the use of the individual or entity named above. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination,
distribution or copying of chis comri1unication is strictly prohibited. If you have received this communication in error, please immediately notify us by telephone, so that we may arrange for the return of the original message to us. Thank you.
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
\
fBJ!.tional Starch and Chem/ca/ Company
10 Finderne Avenue
' P. 0. Box 6500
Bridgewater, New Jersey 0880,-0500
908-685-5000 '
Cable Address: NASPROD,BRIDGEWATERNEWJERSEY
Writer's Direct Dial Number:
Fax Number:
Mr. Jon Bornholm
Remedial Project Manager,
United States Environmental Protection Agency
Region IV
345 Courtland Street, N.E.
Atlanta, Georgia 30365
· March 28, 1996
Subject: Response to NCDEHNR Comments on NSCC Response
to January 18 Comments on Remedial Design/Remedial Action
Work Plan for Operable Unit 3 at National Starch and
Chemical C,ompany's Cedar Springs Road Plant Site,
Salisbury, North Carolina
Dear Mr. Bornholm:
Attached please find responses to NCDEHNR comments on the NSCC response to earlier
('1/18/96) comments by NCDEHNR on the Remedial Design/Remedial Action Work Plan for the
Operable Unit 3 (OU3) at the National Starch and Chemical Company's Cedar Springs Road
Plant site in Salisbury, North Carolina. Altogether there are 16 pages of comments and
responses including with tables and figures. As you have done before with Responses to
Review Comments for Operable Unit 3, we are assuming that you will also transmit these
responses to NCDEI-INR. Also as we have discussed and agreed earlier, we will wait until we
hear from you and the NCDEHNR before we revise and finalize the Remedial Design/Remedial
Action Work Plan for OU3. Please feel free to call me if there are any questions.
Very Truly Yours, ,
(24~~-~
A:bu M. Z. Ala , C.D. P.E:
Director, Envir erital Projects
CC: D. Cregar, NSCC w/o Proposal
R. Paradowski, NSCC
C:\PROJECTS\SALSBR Y\OU3RL TR2.AA
A. Samson, NSCC
M. Ford, NSCC
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
\
Responses to NCDEHNR's Comments (03/13/96) on the
Remedial Design/Remedial Action Work Plan
, . for the Third Operable Unit (OU3)
National Starch & Chemical Company
Cedar Springs Road Plant, North Carolina
A. Work Plan Contents
Comment on NSCC Response No. 1
We disagree. As illustrated in Figure 1-5, the contours to the northwest, northeast, and southwest
cannot be closed based on the information provide.
Response to Comment on NSCC Response No. 1
Please note that the horizontal extent of contamination has been delineated and is presented in
the Draft and Final Remedial Investigation Reports for Operable Unit 3 (IT, March 18, 1993 and
June 2, 1993). During the·Phase II Remedial Investigation of Operable Unit 3, a total of36
groundwater samples were collected as part of the groundwater screening investigation to
establish the extent of groundwater contamination. During this screening process, groundwater
samples were obtained by one of three methods: (a) push-point water sampler, (b) temporary well
screen, or (c) a water sampler equipped with a covered retractable screen. Each groundwater
sample was analyzed at an on-site laboratory for 1,2-DCA. Split samples were sent to an off-
site laboratory in the CLP program for full TCL VOC analysis using CLP approved methods and
Level IV DQOs. Approxirpately, 85 percent of the screening samples were confirmed by the
l'aboratory in the CLP program. The sample locations and analytical results are shown on Figure
1-4 of the RD/RA Work Plan. This figure is the same as Figure No. 4-4 in the IT Report. The
data presented on this figure indicates the following:
a.
b.
c.
Four groundwater monitoring and sampling locations on the cast side of the
Northeast Tributary were found to be uncontaminated;
Four groundwater monitoring and sampling locations on the north side of
Arca 2 of the Plant were also found to be uncontaminated;
Four groundwater monitoring and sampling locations on the west side of
Arca 2 of the Plant and the Lagoon Area were also found to·bc
uncontaminated;
d. Two groundwater monitoring and sampling locations on the south side of the
Lagoon Arca were also found to.be uncontaminated.
C:\PROJECTS\SALSBRY\OU3RES2.AA
I
I
I
I
I
I
I
I
I
I
I
I
I
I
N 850
N 250 -
CHAIN LINK FENCE---~
12dc~V408668 006/03-17•93//S
:z
\
ND,c,
LEGEND
ND GROUNDWATER SCREENING POJNr
6 SHOWING 1,2-DCA CONCENTRATION
,_ __ _ 1,2-0CA CONCENTRATION
10000 _/. CONTOUR
3J"' ,c,4J
ND ,c,ND
.P,
------------
,c,ND
E 250
NOTE: Confirmation data
supplemented by groundwater
screening data
APPROXIMATE SCALE (ft)
0 100 200 300 ~ 500
0 1lj a:
VJ (!) z a: a. VJ a: i:'i w u
FIGURE 4-4
1,2-DCA PLUME IN
GROUNDWATER, PHASE II
OU3RI
NATIONAL STARCH AND
CHEMICAL COMPANY
SALISBURY N.C. rn INTERNATIONAL
TECHNOLOGY
CORPORATION
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Thus, the extent of groundwater contamination in the saprolite zone was well defined
during the Remedial Investigations of OU3.
Following the groundwater screening investigation discussed above, a total of 12 monitoring
wells (NS-33/34, NS-35/36, NS-37/38, NS-39/40, NS-41/42, and NS-43/44) were installed
during phase II of OU3 RI. These new monitoring wells were installed in pairs, one in the
saprolite and one in the bedrock. The six new saprolite wells ( NS-33, NS-35, NS-37, NS-39,
NS-42, and NS-43) as well as two existing saprolite wells (NS-13 and NS-14) were sampled and
analyzed for TCL VOCs by an off-site laboratory in the CLP program under Level IV DQOs. ·
Concentrations of 1,2-DCA from these eight wells and that from three wells (NS-03, NS-12, NS-
24) installed during the Remedial Investigations for OU! and OU2 were used in developing the
1,2-DCA contamination contours. Attached Figure 2-6 reproduced from the Final Remedial
Investigations Report for OU3 (IT, June 2, 1993) shows the locations of these wells. Table I
summarizes the coordinates, ground surface elevations, lengths of screen and screened intervals,
the depth of the boreholes and other pertinent information for the saprolite and bedrock
monitoring wells at this site.
Data collected during the Remedial Investigations OU I, OU2 and OU3 demonstrated that the
contamination at this site originated in the saprolite zone near the ground surface and gradually
percolated down into the bedrock. Table 2 summarizes 1,2-DCA contamination data for paired
saprolite and bedrock monitoring wells installed at the site. Thus, although there are no bedrock
monitoring wells south and west of the Lagoons and Area 2 of the Plant, it is highly unlikely that
the bedrock zones in these areas are contaminated because the saprolite monitoring wells in these
areas are found to be uncontaminated. This was the main reason no bedrock monitoring wells
_/ were installed in these areas.
Groundwater elevations in the saprolite and bedrock zones were measured by IT during the
Remedial Investigations at ()U3. Groundwater contours developed from these measurements in
the saprolite and the bedrock zones were presented in the attached Figures 3-1 and 3-2
(reproduced from the Final RI Report), respectively. Review and evaluation of the data
presented in these two figures and the 1,2-DCA concentration data from the monitoring wells
indicate the following:
a. The two bedrock monitoring wells (NS-34 and NS-44) located on the cast side
of the Northeast Tributary (cast of the Lagoon Arca and Area 2 of the Plant)
were found to be uncontaminated. Therefore, the bedrock zone east of the
Northeast Tributary is uncontaminated;
b. The two bedrock monitoring wells (NS-24 and NS-38) located on the north
side of Area:2 of the Plant were found to be either uncontaminated or
estimated concentration of 1,2-DCA were found to be below the detection
limit (at 1 ppb). Therefore, the bedrock zone north of Area 2 is
uncontaminated;
C:\i'R OJ ECTS\SA LS BR Y\OU3 RES2 .A A 3
D
I
I
I .-
1
I
I
I
I
I
I
I
I
1050 :....
• NS-01A • NS-37/38
NS-24e
:e 1B ...... ,._
750 -
◄50 -
150 -
-150 -
.-450 -
NS-03
'' '' '' '' '' ''
NS-12
.. ,
NS-39/40 • ===c---NS-41/42 □□E:J• 7,,
l...---r::::::::::;~==='-----e NS-14
-750 I
NS-43/44 •
NS-33/34 •
1,
LEGEND
NS-35 MONITORING WELL LOCA TXlN
Q
1§ er
en (') z a: 0.. en er
1§ w u
• AND IDEN11FICAllON
APPROXIMATE SCALE {ft)
f002'0jl)()«)Oa,o
FIGURE 2-6
-650 ·350 .50 250 550 LOCATION OF MONITORING
WELLS USED TO PROVIDE
WATER LEVEL DATA
PHASE II OU3 RI
"°8666.0&0/3•17-lil3/mw_ou3/,.
NATIONAL STARCH AND
CHEMICAL COMPANY
SALISBURY N.C. rn INTERNATIONAL
TECHNOLOGY
COAPORATlON
Coordinates
SAPROLITE WELLS North
NS-01A 1706.56
NS-03 358.1
NS-12 -50.3
NS-13 -417.185
NS-14 -604.148
NS-33 -679.48
NS-35 288.409
NS-37 1646.6
NS-39 -302.572
NS-42 -397.216
NS-43 253.6
BEDROCK WELLS
NS-24 1002.13
NS-34 -662.875
NS-36 302.835
NS-38 1646.6
NS-40 -302.888
NS-41 -406.745
NS-44 253.6
Notes:
SGS = Below Ground Surface
TOC = Top of Casing
East
-462.3 --605.15 ..
-595.89
180.417
94.982
409.374
365.995
-27.1
-66.12
90.258
614
-167.76
409.251
366.143
-27.1
-55.544
88.092
614
Table 1
Monitoring Well, Groundwater and Bedrock Information
Operable Unit 3
Cedar Springs Road Plant Site
Ground Top of
Height of Surface Screen Screen
TOC Riser Elev. Length SGS
(ft.) (ft.). (ft.) (ft.) (ft.)
787.45 1.9 785.55 10 38 .. 1
774:58 -.. 1 :6 772.98 10 8.4
774.58 2.3 772.28 10 10.2
763.09 3.1 759.99 10 4.4
765.7 3.7 762 10 6.3
775.67 2 773.67 10 49
745.05 2 743.05 5 6.5
747.6 2 745.6 10 43.5
765.06 2 763.06 10 30.8
761.32 2 . 759.32 20 60
761 2 759 10 38.5
758.7 2.4 756.3 20 55.1
775.47 2 773.47 15 63.84
744.33 2 742.33 15 25.8
747.6 2 745.6 15 66.5
764.64 2 762.64 20 74.3
760.69 2 758.69 10 122
761 2 759 10 51.75
• = Height of riser on wells NS-33, -35, -37, -39, -42, -43, -34, -36, -38, -40, -42, and -44 is an estimation.
Information presented in this table was taken from Final Remedial Investigations Reports for OU1 and OU3.
Bottom of Top of Bottom of Bottom of
Screen Screen Sreen Borehole
SGS Elev. Elev. BGS
(ft.) (ft.) (ft.) (ft.) ~
48.1 747.45 737.45 48.1
18.4 764.58 754.58 18.4
20.2 762.08 752.08 25
14.4 755.59 745.59 14.4
16.3 755.7 745.7 16.3
59 724.67 714.67 59.5
11.5 736.55 731.55 12
53.5 702.1 692.1 54
40.8 732.26 722.26 41.3
80 699.32 679.32 80
48.5 720.5 710.5 49
75.1 701.2 681 .2 75.1
78.84 709.63 694.63 80.5
40.8 716.53 701.53 41.3
81.5 679.1 664.1 .85.5
94.3 688.34 668.34 94.8
132 636.69 626.69 138
61.75 707.25 697.25 66
D
u
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Paired Wells
NS 33/34
NS35/36
.
NS 37/38
NS 39/40
NS 41/42
NS 43/44
Table 2
Concentration of 1,2 Dichloroethane in
Paired Monitoring Wells
Operable Unit 3
Cedar Springs Road Plant Site
Saprolite Well
(ppb)
ND
72000 D
I J
7000D
82000 DJ
ND
Bedrock Well
(PP~)
ND
11000 D
1 J
99000 D
39000 D
ND
I
B->
···'.·.>/
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
-> 'b
\
1050 -> 'rs-
~
450 -
1 -
' -----------------------' :,--·-----------,------
: : : _____________ 742.s
763 :: '' '' '' '' ''
: :-----------.
" , ..
'' " '' '' : :
'' ''
'' '' ,, <' • I
761 :: '' '
·------_·:_-_-_-~'----- --------. -·-~ = =1---~-----~ ~~~~~.
150 -
.>~ 757•
-450 -LAGOON
• 752.5
?. ~ ;< • 761
-750 I
-650 -350 -50 250 550
40665~ 060/5·11 •93/wt.301 _S/J$
APPROXIMATE SCALE (ft)
0 1 00 200 300 ~ 500
LEGEND
• MONITORING WELL LOCATION
?S? AND GAOUNDWA TEA
ELEVATION (ft, MSL)
FIGURE 3-1
GROUNDWATER ELEVATION
CONTOUR MAP, SAPROLITE
WELLS MARCH 1 , 1993
NATIONAL STARCH AND
CHEMICAL COMPANY
SALISBURY N.C. m INTERNATIONAL
TECHNOLOGY
CORPORATION
I
D
I
I
I
I
I
I
I
I
I
I
I
I
I
I
><'v ~
········ 730 --------t-
1050 -735
.. 735 ---:::::::=------------
750 -
450 -:: ----------~ ,------
:; : : o, 'I :: ': " "
' ' '' , , ', '' '' '' ,:
'' '' '' '' ' :
···········'· .. 740
" " ············~i .. . . : : : ,-------------, --·-····~~ ········~--:. :
' ,'
" " :: : : ·················· 7~5 --+----
150 -" " " ::
'' '' : : ·:
'' ............ i i·:-·····
" . ······-·-· ............. ~-
-150 -
757 e
GOON LAGOON I L--t+-.---t-h 2
-750 I -f··· .. ·······1·-.
-650 -350 ········:50----
408668.060/S· 1 Hl3/'M.301 _t:>/i,;
/ /
I 'l{f
250
e76B
550
APPROXIMATE SCALE (ft)
1 00 200 300 "400 500
LEGEND
• MONITORING WELL LOCATION
767 LOCATION AND GROUNDWA TEA
ELEVATION (ft MSL)
FIGURE 3-2
GROUNDWATER ELEVATION
CONTOUR MAP, BEDROCK
WELLS MARCH 1 , 1993 ·
NATIONAL STARCH AND
CHEMICAL COMPANY
SALISBURY N.C. rn INTERNATIONAL
TECHNOLOGY . -
CORPORATION
I
B
D
I
I
I
I
I
I
I
I
I
I
I
I
I
I
c.
d.
e.
I
At this site groundwater flows north from the Lagoon Area and the water
level drops at least 4 feet in a distance of about 200 feet from the southeast
corner to the northeast corner of Lagoon 2. Because of this large hydraulic
gradient (0.02 ft/ft) towards the north the contaminated groundwater from
the Lagoon Area cannot flow south. Thus, the bedrock zone south of the
Lagoons should be uncontaminated;
At this site the bedrock wells are always found to be uncontaminated when
the upper saprolite wells at the same locations are uncontaminated. The
saprolite monitoring well NS-14 located south of the contaminated area at the
Lagoons was found to be uncontaminated. Thus, the bedrock zone south of
the Lagoons should also be uncontaminated where the saprolite monitoring
wells indicate no contamination; and
On the western side of the Plant Area the groundwater flows northeast from
southwest and the water level drops at least 5 feet in a distance of 470 feet
from monitoring well NS-12 to the edge of the contamination detected in
Area 2. Because of this significant hydraulic gradient (0.0106 ft/ft)
contaminated groundwater from Area 2 and the Lagoon Area cannot flow
west or southwest. Saprolite monitoring wells NS-03 and NS-12 were found
to be uncontaminated. Thus, the bedrock zone west of Area 2 and the
Lagoon Area should be uncontaminated.
The five proposed bedrock extraction wells are expected to have radii of influence ranging from about 300 feet to about 500 feet. When the proposed bedrock extraction wells are installed and
operational, NSCC plans to monitor drawdowns in the surrounding saprolite and bedrock
monitoring wells, particularly monitoring wells located (a) to the south of the Lagoons, (b) to
the west of the Lagoons and Area 2, and (c) to the north of Area 2. This drawdown monitoring
will determine the area of influence of the proposed bedrock extraction wells. If the drawdown
measurements indicate that the area of influence of the proposed bedrock extraction wells does not extend to the existing monitoring wells to the north and west, NSCC will consider installing
one new bedrock monitoring well between NS-24 and Area 2 and one new bedrock monitoring
well west of Area 2.
As discussed during the Mar.ch 26 telephone conference installation of bedrock monitoring wells are expensive and time consuming. NSCC's primary objective is to cleanup this site as soon as possible and in a cost effective manner. NSCC believes that installation of additional bedrock monitoring wells is unnecessary, will delay the startup of the project and will waste resources.
Therefore, NSCC does not i~tend to install these two new bedrock monitoring wells until the need for these wells are demonstrated.
C:\PROJECTS\SALSBRY\OU3RES2.AA 9
D
n
u
I
I
I
I
I
I
I
I
I
I
I
I
I
Comment on NSCC Response No. 2
As illustrated in Figure 1-6 there is insufficient data for closing the contours to the northwest,
west, and south of the contaminated zone. If there is additional information, please show in on
Figure 1-6. If there is no additional data, then additional monitoring wells are needed.
Response to Comment on NSCC Response No. 2
The extent of groundwater contamination has been delineated and was presented in the Draft and
Final Remedial_Investigation Reports for Operable Unit 3 (IT, March I 8, 1993 and June 2, 1993).
The contours provided in Figure 1-6 are based on the concentrations of 1,2 DCA in the bedrock
monitoring wells and on the distribution of 1,2 DCA concentrations at the water table
extrapolated to the bedrock zone in the area where there are no bedrock monitoring wells.
Figure 1-6 in the OU3 RD/RA Work Plan shows that 1,2-DCA was found to be non-detect in
bedrock wells located to the east and north of the plant in wells NS-24 and NS-38 located on-site
and directly down gradient of contaminated plume.
The extrapolation of the bedrock contours based on the distribution of 1,2 DCA at the water table
is a sound approach. It is based on the fact that the hydraulic conductivity of the saprolite zone
has been determined to be 3 times larger than the hydraulic conductivity of the bedrock zone and
on the fact that the hydraulic gradients in the saprolite and the bedrock zones are virtually
identical. The hydraulic conductivity of the saprolite and the bedrock have been previously
determined to range from 0.72 to 3.35 ft/day and 0.01 to 1.13 ft/day, respectively. The hydraulic
gradients for the saprolite and bedrock zones were presented respectively in figures 3-1 and 3-2
of the Final OU3 RI Report and are attached to this response.
The data presented in these figures demonstrate that the nested saprolite/bedrock wells have
similar potentiometric surfac,es. This indicates that the bedrock and saprolite zones are
interconnected. These figures also show that the direction of groundwater flow from both the
east and west is generally towards the Northeast Tributary and overall along the Northeast
Tributary. Monitoring well data further indicates that the migration of the contaminated plume
in the bedrock zone has yet to reach the two on-site bedrock monitoring wells (NS-24 and
NS-38) located on the north side of Area 2. This is also supported by the delineation of the
1,2 DCA at the water table (saprolite zone). Since the saprolite zone is a more conductive zone,
the northerly migration of the contamination plume should be faster in the saprolite. Because of
this, the leading edge of the contamination plume in the saprolite zone should be beyond the
leading edge of the contaminant plume in the bedrock. Therefore, the outer limits of the
contaminated plume in the saprolite"zone can be used to conservatively estimate the leading
edge of the contaminated plume in the bedrock zone and thus allow closure of the bedrock
contours. Because of this reasoning NSCC believes that additional bedrock monitoring wells are
unnecessary and will waste resources.
As discussed during the March 26 telephone conference with USEP A and the NCDEHNR and as
C:\PROJECTS\SALSBRY\OUJRES2.AA 10
D
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
1050 "' I:: L
'-
750 ' ,-
' T"
' 450 -I
_,
150
-150
-------
-450 -
-750 I
./350
, ,
' ,
'
"' ~
',
I I
I I
, , ,
' ,
,
'
' -
--~l-:-,
11
□
' , ,
,
'
.350
' ,
'
, ,
' ' '
' '
I
-50
' ' ' ' ' '
, , ,
' ' ' I
' ' ' ' '
,
' '
' ' ' ' '
' ' ' ' ' '
' ,
' '
-,
' ,
' '
' ,
' '
' J---1-~i ---

-
..2,0_ -
' , , , , f ',," ' , , ' , , ' , ' ', ' , ' ' , ''
, ,
',
' ' ' ' ' ' ' ' '
i '
' '
, ,
' '
550
' ' '
II
LEGEND
1,2-DCA CONCENTRATION
CONTOUR IN PPM
72WJ 1,2-0CACONCENTRATION
IN PPB, GROUNONATER
SMP!.ES * II PROPOSED EXTRACTION
WELL LOCATION
0 ci
O'.
(f)
(!) z ii'
tl. (f)
O'. <(
0
UJ
0
"'
IGURE 1,6
SCALE(!t)
"' "' "'
1,2-DCA IN BEDROCK
GROUNDWATER SAMPLES,
PHASE II OU3 RI
NATIONAL STARCH AND
CHEMICAL COMPANY
SAUSBURY N.C.
...
I
I
D
I
•
I
I
I
·•
I
I
I
I
I
I
I
I
I
I
mentioned in Response No. 2, if after installation and operation of the proposed saprolite and
bedrock extraction wells it is determined that the area of influence of these extraction wells do
not extend far enough lo include the entire contaminant plume, then NSCC will consider
installation of additional monitoring wells to the north and west of the contaminated areas.
Comment on NSCC Resp_onse No. 4
In light of the lack of data on the bedrock zone, at a minimum two additional monitoring wells,
one north and one west of !he known plume should be installed. In our previous comment, we
provided a diagram with suggested locations.
Response to Comment on NSCC Response No.4
As discussed during the March 26 telephone conference with the USEP A and the NCDEHNR,
NSCC believes that there is enough bedrock monitoring wells and supporting data lo show that
additional bedrock monitoring wells are unnecessary and wasteful of resources. Initially NSCC
plans to installation of the five new bedrock extraction wells as proposed in Figure 2-2 and 2-4.
Upon installation of these bedrock wells step-drawdown tests will be conducted to determine
their yields and area of influence. If results of these tests indicate that the area of influence of
these wells does no( extend far enough to cover the entire contaminant plume then NSCC will ·
consider installation of additional wells.
Comment on NSCC Response No. 5
\\'.ithout an analysis of site-to region-scale fracture patterns, it will be difficult to interpret the
orientation and significance of fracture zones found during coring;geophysical logging, or
packer testing.
Response to Comment on NSCC Response No. 5
NSCC appreciates the comment but cannot waste resources to investigate regional bedrock
fracture patterns. • As required by the EPA's Record of Decision, NSCC's objective is to extract
and treat the contaminated groundwater to remediate the contamination as expeditiously and as
cost-effectively as possible. Therefore, NSCC intends to implement the activities identified in
the RD/RA Work Plan for OU3. NSCC believes this will delineate the vertical extent of the
groundwater contamination in accordance with the Record of Decision.
C:\PROJECTS\SALSURY\OU3RES2.AA 12
-- - - - - - - ---" 19 17 ta " 20 " 22 " ,.
' ' ' ' ,-4---1-.--.,---,---1---i---r--r c:"-
1 I I I I I I I I
I I I I l I I ~---1-•-~--~---1---~--~--~--I I I I I I I t I
I I I I I --1-~-~---1---1---~--~--~--
I I I I I I I
"
"
n
"
"
"
"
"
-I!!!!!!! I!!!!
I EGEND·
• NS-44 EXISTING MONITORING WELL
• PROPOSED BEDROCK EXTRACTION WELL
GROUNDWATER FLOW-PATH
APPROXIMATE EXTENT OF GROUND'NATER
CONTAMINATION AT THE LAGOON AREA
Notes: Monitoring well NS 41/42 ■re not shov.11.
SCALE:
1 ""j
FIGURE 2-4
LAGOON AREA
PROPOSED BEDROCK
EXTRACTION WELL POSITIONS
NATIONA1. STARCH ANO a-fEMICAL COMPANY
CEDAR SPRINGS ROAD
SALISBURY, NORTH CAROLINA
---

-
----" " " " ,.
' ' ' -~--}--+---~--~--~--
' ' ' I I I I I I
---r--r--1--,--7---
10 I I I I I
___ ~lll'J).JB.E fON,;: --:: ;::--
' 1 I I I
-1 --,---r--r--r--
1 I I I
' ' ' ---,---, --, --
'
" ' ' ' ' ' ---~--r--~--~--~--
" 1 I I I
' '
"
-

-
J
i
-I!!!!!!
I EGENP·
•
EXISTING MONITORING WELL
PROPOSED BEDROCK EXTRACTION WElL
GROUNOWATER FLOW PATH
APPROXIMATE EXTENT OF GROUNDWATER
CONTAMINATION AT THE PLANT AREA
SCALE:
i w
FIGURE 2-2
PLANT AREA
PROPOSED BEDROCK
EXTRACTION WELL POSITIONS
NATIONAL STARCH ANO CHEMICAL COMPANY
CEDAR SPRINGS ROAD
SALISBURY, NORTH CAROLINA
lllilj1
I
H
D
I
•
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Comment on NSCC Response No. 6
Computer modeling does not delineate a contaminant plume. Without the additional monitoring
wells suggested above, the effectiveness of the proposed extraction system will be difficult to
evaluate.
Response to Comment on Response No. 6
NSCC agrees that the computer modeling was not performed to delineate the contaminant plume,
but was used to determine the needed extraction rates and well placements to effectively extract
the contaminated groundwater. However, computer models have been and can be used to
delineate contaminant plumes when they are first developed, calibrated and verified with data
from the field.
NSCC believes that a sufficient number of monitoring wells have been installed at the site during
the Remedial Investigations of OU!, OU2, and OU3 to evaluate the effectiveness of the proposed
extraction wells.
Comment on NSCC Response No. 7
Generally, geophysical logs are used to determine lithology and make stratigraphic correlations
in sedimentary sequences and would be helpful ifwe were working the Costa! Plain geological
province. Where has geophysical logging been used to determine lithology and make
stratigraphic correlations in the Piedmont Province? Exactly which geophysical logging
techniques are NSCC proposing to use?
Response to Comment on Response No. 7
Based on the March 26 telephone conference discussions with the USEPA and the NCDEHNR,
NSCC will eliminate the proposed geophysical logging, and will rely on rock core data and
results of packer testing to determine fracture zones and contamination zones. The data obtained
from the rock cores will be used to identify the packer test zones.
Comment on NSCC Response No. 11
Approval by NCDEHNR will be necessary before the reporting period is changed.
Response to Comm·ent on Response No. 11
NSCC will coordinate with and receive approval from the USEPA and the NCDEHNR before
the reporting period is changed for this project.
C:\PROJECTS\SALS£3RY\OU3RES2.AA 15
. -
B
D
D
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Responses to NCDEHNR Comments (03/13/96) on the
Health and Safety Plan
for
Remedial Design/Remedial Action Work Plan
for the Third Operable Unit (OU3)
National Starch and Chemical Company
Cedar Springs Road Plant, North Carolina
Comment on NSCC Response No. 4
The OVA is calibrated to methane at factory. Table 6 shows the relative responses for selected
organic compounds relative to methane. Unless the identity of the chemical being detected is
known, its concentration cannot be determined. The proper indicator is meter units not "ppm".
Response to Comment on NSCC Response No. 4
The suggested change of "ppm" to "meter units" has been incorporated into the Revised RD/RA
Work Plan for OU3.
C:\rROJECTS\SALSBRY\OU3RES2.AA 16