NCD981927502_19970519_Geigy Chemical Corporation_FRBCERCLA RA_Response to EPA-DEHNR Comments Draft Downgradient Groundwater RA Work Plan-OCR

May 19, 1997
Geigy Chemical Corporation Site
Aberdeen, North Carolina
Committee Correspondence
RECEIVED
MAY 2 O 199?
Ms. Giezelle Bennett
Remedial Project Manager SUPERFUND SECTION
USEPA Region IV, North Superfund Remedial Branch
100 Alabama Street, S.W:
Atlanta, GA 30303-3104
RE: Response to EPA and NCDEHNR Comments
VIA FEDERAL EXPRESS
Draft Downgradient Groundwater Remedial Action Work Plan
Geigy Chemical Corporation Site
Aberdeen, North Carolina
Dear Giezelle:
On behalf of Olin Corporation, Novartis Crop Protection; and Kaiser Aluminum & Chemical
Corporation (the Companies), and in response to om meeting of February 26, 1997, please find
enclosed two (2) copies of the Companies' responses to the February 19, 1997 comments on the
Draft Downgradient Groundwater Remedial Action Work Plan.
To facilitate distribution, one copy has been sent directly to Mr. Randy McElveen ofNCDEHNR
and Mr. Tim Eggert ofCDM.
If you require additional copies of the comment responses, or have any questions about the
proposed limited action alternative, please contact me at [phone].
Regards,
,d ~ l+~/4A
Garland Hilliard
Project Coordinator
/Enclosure
c: R. McElveen (NCDEHNR)
T. Eggert (COM)
H. Moats (Novartis)
G. Crouse (Novartis)
H. Grubbs, Esq. (WCS&R)
B. Vinzant (Kaiser)
M. Sheehan (Rust)
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• •
RESPONSE TO USEPA COMMENTS
DATED FEBRUARY 19, 1997
ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
MAY 1997
Rust Job No. 37222
Rust Environment & Infrastructure
Greenville, South Carolina
~SPONSE TO USEPA COMMENt
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
GENERAL COMMENTS
General Comment No. I
The Agencies would like the PRPs to consider the following as an alternative: Choose a limited
action alternative in which the PRPs would conduct monitoring of the groundwater and surface
water for an agreed upon amount of time to gather data to determine if the modeling results are
accurate and reflect future site conditions and contaminant concentrations. If the monitoring
shows that the modeling is accurate, then the limited action alternative would continue. If the
monitoring does not reflect the model, then a pump and treat alternative would be implemented.
Response:
As discussed during our meeting with the Agencies on February 26, 1997, the Companies agree
to implement the limited action alternative. Monitoring will be conducted at the locations
described in the RA WP and will occur quarterly during years one through three, semi-annually
during years four through five, and annually thereafter. Previously proposed and additional
monitoring locations requested by the Agencies are shown in Figure I, and will be reflected in the
revised Draft RAWP.
Monitoring results will be reviewed with the Agencies at the end of the initial three-year period,
and every five-year period thereafter ( coincident with the facility property remedy reviews), to
evaluate and ensure the continued protection provided by the limited action alternative. Results
will be compared with model estimates of future pesticide concentrations. The model will be
updated as necessary with available monitoring data. The need to modify sampling locations
and/or frequencies will also be evaluated during remedy review meetings.
The RA WP will be revised to reflect periodic monitoring and source control as the proposed
remedy for the downgradient area. Reference to natural attenuation as the proposed remedy will
be eliminated to address previous comments by EPA.
General Comment No. 2
The supplemental responses lo comments on the draft Downgradient Remedial Action Work Plan
(dated February 3, 1997) are inadequate with respect to the intended purpose of this document.
The inadequacies are as follows:
I May 1997
'SPONSE TO usEPA coMMEA
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
a) It.is standard procedure to sum the risks across pathways when presenting results
of the risk characterization. It is not appropriate to present the risk associated
with a single exposure route (incidental ingestion of surface water) as is done in
the response to comments. Risks associated with ingestion and dermal contact
with sediment, and ingestion and dermal contact with surface water should be
summed to fully reflect the potential risk.
b) The calculations of risk based concentrations (remediation goals) for human
exposure to surface water are not consistent with EPA Region IV guidance. Per
Region IV guidance, all significant routes should be considered in the back
calculation, not only the "risk driver" as is referenced in the response to
comments. In other words, ingestion of surface water, in addition to dermal
contact, should have been considered This will have the effect of slightly
lowering the human health risk-based concentrations presented in Table 3.
c) Derivation of the dilution factors is not presented Without this information, it is
impossible to comment on the· significance and applicability of the simulated
future surface water concentrations.
Response:
a. Table 1 lists cumulative human health risks summed across all suiface water and sediment
pathways. The cumulative risks are well below USEPA's IE-04 to IE-06 excess lifetime
cancer risks and the 1.0 hazard quotient action levels for Superfund sites. These results
further support the position that current groundwater discharges of chemicals to suiface
water do not pose a human health risk.
b. Table 2 presents risk-based concentrations for human exposure to suiface water calculated
per USEPA Region IV guidance.
c. Dilution factors were calculated following methods used by the United States Geological
Survey (USGS) to apportion drainage basin contributions to river/stream flow.
2 May 1997
.RESPONSE TO USEPA COMME!.
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWN GRADIENT REMEDIAL
ACTION WORK PLAN
Calculations used to determine simulated future surface water concentrations are attached
(Table 3). Actual dilution rates would be calculated at the time of sampling.
General Comment No. 3
It was noted in the January 21, 1997 meeting that phytoremediation would be difficult to
implement along Aberdeen Creek due to the current development of this area. It should,
however, be able to be implemented along McFarland's Branch, which is presently undeveloped.
McFarland's Branch is the one creek which is most likely to be impacted by groundwater
discharge of the contaminants since it is the closest groundwater discharge point to the site and
it has the least ins/ream dilution. Therefore, implementation of phytoremediation along this
creek could provide more confidence in the natural attenuation alternative.
Response:
The Companies believe natural phytoremediation is already occurring along the maJonty of
McFarland's Branch. The area along McFarland's Branch is heavily wooded and includes
numerous large poplar trees. Poplars have deep root systems and can transpire 50 to 350 gallons
per day of groundwater. The Companies believe that the existing tree cover around McFarland's
branch is extensive and does not require additional planting.
General Comment No. 4
The PRPs have not been responsive to the Agencies comments. The Agencies comments with
respect to additional monitoring before and during the remediation process have been
reasonable and technically valid and therefore, need to be given an appropriate response. The
Agencies wish to move forward with this project without further delays.
Response:
As discussed during our meeting of February 2611\ the Companies wish to proceed with the limited
action alternative without further delays. Proposed monitoring locations presented in the Draft
RA WP and additional monitoring locations requested by the Agencies are shown on Figure I.
Based on discussions during the February 26th meeting, the following changes and clarifications
will be incorporated into the RA WP:
3 May 1997
MW-29D
• • RESPONSE TO USEPA COMMENTS
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
MW-29D has been previously shown to lie outside of the hydraulic limits of the downgradient
area. Water-level measurements will be recorded at MW-29D and MW-29L during each period
monitoring event. Sampling of MW-29D would be included in the monitoring program if
hydraulic data indicate that this location no longer lies outside of the downgradient area. The well
would be sampled on the same frequency as other monitoring wells included in the limited action
alternative.
Town Well No. 2 Sentinel Well
A new well (MW-36L) will be installed into the Lower Black Creek aquifer at the location shown
in Figure I, to address the State's request to monitor groundwater quality midway between Town
Well No. 2 and the estimated extent of pesticides in the Lower Black Creek aquifer. As
previously noted by the Companies, flow model simulations indicate that the capture zone for
Town Well No. 2 extends to the east-southeast and away from the extent of pesticides in the
Lower Black Creek aquifer (Figure 2). The Companies believe that the proposed well location
will be suitable to provide prior indication of potential impacts to Town Well No: 2.
Stream Surface Water and Sediment Monitoring
Baseline surface water and sediment monitoring will be conducted in McFarland's Branch,
Aberdeen Creek, and Ray's Mill Creek. Surface water and sediment monitoring will then be
conducted in McFarland's Branch in conjunction with the routine groundwater monitoring events.
The need for subsequent sampling of the other surface waters will be determined using sentinel
groundwater monitoring wells along Aberdeen Creek (MW-32L and MW-38L) and Ray's Mill
Creek (MW-39L). Surface water and sediments will be sampled at those locations where the
groundwater results exceed trigger levels. The trigger levels are provided in Table 2 of
Attachment I .
Monitoring Frequency
The Companies agree to sample downgradient monitoring locations on a quarterly basis through
the first three years of the remedy. Results will be evaluated with the Agencies during an interim
remedy review meeting at the end of year three. Concentration trend data will be reviewed and
compared to modeled concentration trends.
4 May 1997
.RESPONSE TO USEPA COMME~
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
The Companies propose to conduct semi-annual sampling of downgradient monitoring locations
during years four and five of the remedy, and annual sampling thereafter. Monitoring frequencies
and/or locations will be revised as appropriate during the five-year periodic remedy reviews.
General Comment No. 5
At this time, we do not have a proper characterization of the plume in the Lower Black Creek
aquifer. MW-31L is contaminated above the groundwater standards. One additional
monitoring well to the east-southeast of MW-3JL should be installed to verify the extent of the
plume in this area. A round of surface water and sediment sampling in the surrounding surface
waters is also required Surface water and sediment sampling should be very thorough and
include all appropriate background samples on Ray's Mill Creek and McFarland's Branch. At
least two samples should be taken between Ray's Mill Creek and McFarland's Branch in
Aberdeen Creek and one sample in Aberdeen Creek downgradient of the convergence of
McFarland's Branch and another approximately one quarter mile downgradient of the
convergence with McFarland's Branch.
Response:
The Companies will install one additional monitoring well (MW-381) into the Lower Black Creek
aquifer at a location west of MW-3 IL (pending receipt of an access agreement) to verify the
extent of pesticides in the western portion of the downgradient area (Figure I). The well will be
installed adjacent to an additional surface water monitoring station on Aberdeen Creek. Data
from this well and the adjoining surface water station, in addition to data obtained from MW-321
and its adjoining surface water station, will be used to verify estimated surface water/groundwater
dilution ratios included in calculations of future surface water concentration trends ( see specific
comment no. !, below).
The Companies will conduct surface water quality monitoring along McFarland's Branch at the
locations shown in Figure I. Select locations will be verified with the Agencies following field
reconnaissance.
Sediment sampling in Aberdeen and Ray's Mill Creek will be conducted on a contingent basis, as
discussed in general comment response No. 4.
5 May 1997
.RESPONSE TO USEPA COMME.
General Comment No. 6
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
The proposed Record of Decision Amendment or Remedial Action Work Plans should include a
decision tree to guide the Agencies and the PRPs to a protective remedy if it is determined that
natural attenuation is not achieving the remediation goals in a "reasonable time frame ~ We
must determine what treatment alternatives will be appropriate and which site specific conditions
will trigger a specific alternative: i.e., if a surface water body is or becomes contaminated above
an acceptable risk level, a pump and treat alternative could be implemented upgradient of the
water body to contain the contaminant plume.
Response:
A draft decision tree to guide the evaluation of the limited action alternative monitoring program
is attached for the Agencies' review. A comparison of the trend data to the model would be held
during the interim remedy evaluation (year 3) and every five years thereafter. The decision tree
will be updated, as necessary, during periodic remedy reviews.
Confirmation that the limited action alternative remains protective will be based on the following
criteria:
• determination that drinking water supplies are protected;
• observed and estimated groundwater water quality concentration trends substantially agree;
and
• pesticide concentrations in surface water and/or stream sediments are below risk-based action
levels.
Because several factors may be involved in the need for corrective action, and since associated
conditions may be transient, specific corrective action alternatives cannot be specified at this time.
Any potential corrective actions would be evaluated with the Agencies prior to implementation.
General Comment No. 7
General Comment Response pg. 5 -In the third paragraph, it should be noted that even though
the pesticide concentrations are in the low part per billion range, they are still 2 orders of
magnitude higher than the cleanup goals, and thus will require significant attenuation
(degradation, dilution, sorption, etc.) before cleanup goals are reached
6 May 1997
I
.RESPONSE TO USEPA COMMEN'8
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
With respect to the thiri paragraph, EPA does not agree with the PRPs contention that the
remedy efforts should focus on the measurement of attenuation results and not the study of the
degradation processes. z1ck of understanding as to how the pesticides are degrading at the site I
could lead to undesirable consequences, as the by-praducts of degradation could be more
I detrimental than the pesticides themselves. A degradation study should be performed as part of
the monitoring program, so that a full understanding of the natural attenuation processes is
achieved.
Response:
The Companies continue to believe that monitoring of BHC concentrations in groundwater is the I .
most appropriate approach for detennining remedy effectiveness at the Geigy Site given practical
considerations associated lith monitoring for degradation products. Most importantly, however,
this approach also will b~ protective given that degradation products are less toxic than parent
BHC compounds. The !basis for our reasoning is outlined briefly below. More detailed
information and supportinl citations are presented in Attachment A to this document.
• BHC degradation is complex and can produce more than 30 daughter products via
chemical and biological mechanisms (Table 4). Many of the degradation products can
react with each ottler or can be further acted upon by chemical and biological processes,
producing even Jore daughter products. This high number of daughter products
complicates monitdring and virtually eliminates the possibility that the monitoring results I
•
could be used to detennine the degree to which degradation has occurred. Ultimately,
BHC degradation fesults in production of carbon dioxide, water, and hydrogen chloride
• I
which are chemically indistinguishable from that occurring naturally in the environment.
BHC degradation !products are less toxic than the parent compound. In fact, BHC
I
degradation basically mimics human metabolic detoxification processes. Table 5 presents I
chronic toxicity values (or acute values, absent chronic values) for BHC isomers and
daughter products. As can be seen, daughter products are less toxic than the parent BHC
isomers. In fact, pentachlorocyclohexene (PCCH), which is one of the initial BHC
degradation products, is nearly 40 times less toxic than the parent compound lindane.
7 May 1997
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• RESPONSE To USEPA coMMEfs
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
Similar relationships are apparent for all other degradation products for which toxicity
data are availablel Thus, BHC degradation will reduce the toxicity of chemicals present in
the groundwater.
Standard analytical methods have not been developed for the maJonty of daughter
products. Tabld 6 identifies BHC daughter products and identifies those for which
I
USEP A has developed analytical methods. As can be seen, methods are available for less
than one-third ofithe compounds, and no method is available for PCCH or the other initial
degradation product, tetrachlorocyclohexene (TCCH).
Daughter prodjts will be present at non-detectable concentrations. Total BHC
concentrations inlgroundwater are generally in the range of 10 µg/L or less. Degradation
processes that lead to the formation of more than 3 0 daughter products will produce
concentrations ,ell below these initial concentrations. As can be seen from Table 6,
quantitation limits for the few daughter compounds for which they exist are comparable to
or greater than th1e current concentrations of parent BHC.
For these reasons, the Companies maintain that monitoring of BHC concentrations ts an
appropriate and health protective approach for determining remedy effectiveness at the Geigy
Site.
General Comment No. 8
General Comments Response page 7 -EPA disagrees with the PRPs assertion.that the proposed
monitoring plan is adeq~ate to evaluate the effectiveness of the proposed remedy. Because of
the great uncertainty as)ociated with the modeling results which are used to support selection of
the natural attenuation ~lternative, a much more extensive monitoring plan is needed to verify
that the remedy is and r1mains protective of human health and the environment. If the natural
I attenuation alternative is selected, the monitoring plan should be revised per EPA '.s previous
comments. In addition, la decision tree and detailed contingency plan should be developed, in
the event that natural attenuation is found through monitoring to be ineffective.
Response:
Please see general comment responses I, 4 and 6.
8 May 1997
General Comment No. 9
SPONSE TO USEPA COMME~
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWN GRADIENT REMEDIAL
ACTION WORK PLAN
The North Carolina 2L Standards are one ARAR which applies to the State groundwater
standards. It also gives alternatives such as natural attenuation as a means to meet these I . standards. However, there are also Federal ARARs concerning groundwater that must be met.
Therefore, NCAC 2L aldne cannot be a viable alternative since it does not apply to Federal
ARARs. Throughout thei document, specifically comment numbers 2, 7, and 15 still stand and
should be incorporated as previously noted.
Response:
The Companies will revise the RA WP per the changes requested in comments 2, 7 and 15 of the
I Agencies submittal dated December 19, 1996.
. I
Section 5.0 of the Draft 1RAWP will be re-titled "Remedy Protectiveness". The first paragraph
under Section 5.1 will bel deleted to remove discussion of the North Carolina 21 standards. The
first sentence in Section 5.2.2 will be revised to reflect the Agencies comment that North Carolina
21 standards are an applibable ARAR.
The subheading"Statutol Compliance" under Section 7.0 (Conclusions) will be revised to read
"Remedy Protectiveness"!. The first (bulleted) paragraph will also be deleted.
9 Mayl997
I •
.RESPONSE TO USEPA COMMENTS
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
SPECIFIC COMMENTS
Specific Comment No. 1
The Future Surface Water Concentrations paragraph on page 6 states that concerns of potential
I future pesticide concentrations in surface water will be addressed by estimating future surface
water concentrations. Itlis assumed that this will be accomplished by modeling of surface water
to groundwater ratios. 1This information is valuable and should be completed and verified by
analyzing actual surface water concentrations in the creeks and the ratio may then be calibrated
to fit the real data.
Response:
Estimated future pesticide concentrations in surface water were provided to the Agencies in the
Supplemental Comment !Responses dated February 3, 1997. The estimates were prepared for
each of the four transport scenarios evaluated in the RA WP and were calculated using the surface
water/groundwater dilution ratios discussed in general comment response 2c.
Monitoring results for tL two adjoining groundwater and surface water locati~ns proposed for
Aberdeen Creek, and th~ two adjoining groundwater and surface water locations proposed for I
McFarland's Branch, qigure 1) will be used to calculate actual surface water/groundwater
dilution ratios (following subtraction of background concentrations, if any). Calculated surface
water/groundwater dilution ratios will then be used to prepare future concentration trend I
estimates for Aberdeen Creek and McFarland's Branch. Differences, if any, between previously
I
estimated and observed dilution ratios for Aberdeen Creek will be used to refine the dilution ratio
I estimate for Ray's Mill Greek.
Specific Comment No. 2
Additional Monitoring)age 7 -Please respond as directed in general comments 1 and 2 and as
stated in the January 21) 1997 meeting. The Agencies cannot accept modeling without adequate
verification from monitdring wells and surf ace waters.
Response:
The Companies will conduct monitoring at the additional locations indicated in Figure I, as
described in the respons~ to General Comment No.4, to confirm model results. Monitoring data
10 May 1997
I
LsPoNsE TO usEPA coMMEA
DA TED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
will be evaluated with the Agencies during the interim remedy review meeting (year 3) and
subsequent five-year reJedy review meetings. Results will be used to annually update the flow
and transport model. Cbmparison of observed and predicted concentration trends will allow
assessment of the accurall y of future concentration trend estimates. ·
Specific Comment No. 3
Conceptual Groundwater Extraction System page 7 -All aquifers must be sufficiently monitored
to evaluate the effectivehess of the model and to aid in making proper management decisions
about potential actions Jhich may need to be taken.
Response:
The conceptual groundwater extraction system will be expanded to contain the migration of
I
pesticides in the Upper Black Creek aquifer from discharging to McFarland's Branch. Associated
transport simulations aJd remedy cost estimates will similarly be revised. Results will be
I presented in the revised Draft RA WP.
Specific Comment No. 4
I
The State has reviewed the Groundwater Quality Sample Results for MW-33S, and other shallow
monitoring wells in thislarea, dated January JO, 1997 and the response in the RAWP, page 7.
The potentiometric data: seems to indicate the potential for considerable seepage to the Upper
Black Creek Aquifer. Therefore, in order to verify that higher concentrations of pesticides have
not moved directly to th1 Upper Black Creek aquifer, we request that one additional monitoring
well be installed approtmately 200 to 300 feet north of MW-33S in the Upper Black Creek
aquifer.
Response:
The Companies agree to install one additional monitoring well in the Upper Black Creek aquifer
at the location shown in I Figure I, pending receipt of the property access agreement and approval
of the Final RA WP. Work will be coordinated with the installation of the additional monitoring I
wells in the downgradient area. The well will be sampled on the same frequency as the I
downgradient area monitoring wells. Results will be evaluated with the Agencies as part of the
interim (year three) rem1edy review and used to determine the need for continued monitoring at
this location.
11 May 1997
Specific Comment No. 5
I
'SPONSE TO USEPA COMMENt
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
For Comment No. JO, the location of the private well needs to be included on the map, because
this is one of the main riasons why natural attenuation cannot be approved at this Site. The
name of the owner doel not have to be included, but the fact that a private well is still
operational must be inclu~ed on this map.
Response:
The location of the private well will be included on the map showing existing monitoring well and
stream staff gauge locatio1ns (Figure 2-3 of the Draft RA WP).
Specific Comment No. 6
EPA Region JV risk assessment guidance does not allow the rationale taken by the PRPs in
comment/response #13(A). The child's head and mouth must be included in the risk
calculations. Swimmin~ conditions may always be created in even the shallowest of surface
waters. Please make appropriate changes to the McFarland's Branch Risk Assessment.
Response:
The Companies have calculated surface water ingestion risks in response to this comment.
Table 7 provides the equ~tions and assumptions for this pathway. Table 8 presents the resultant
risks. As was the case fJ all other pathways, the calculated risks are well below USEPA's IE-04
to IE-06 excess lifetime !ancer risks and the 1.0 hazard quotient action levels for Superfund sites.
These results further suJport the position that current groundwater discharges of chemicals to
I surface water do not pose a threat to human health.
Specific Comment No. 7
Response #14 -The PRPs state that dilution of the groundwater entering Aberdeen Creek will
reduce the concentratiolis of the pesticides in the creek below levels of concern. The accuracy of
this statement, however,/ is unknown since the background concentrations of the pesticides in
Aberdeen Creek are unlmown. If the background concentrations of the pesticides are near the
levels of concern, the I added mass from future groundwater discharge may increase the
concentrations above the levels of concern. Assuming that the pesticides discharging with the
I
groundwater will be diluted by "clean" surface water is inappropriate for Aberdeen Creek.
Therefore, the monitorihg program should include sampling of surface water and sediment in
12 May 1997
~ • RESPONSE TO USEPA COMMENTS
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
Aberdeen Creek, so that a complete evaluation of the contaminant distribution/migration in the
area and the potential im1acts can be made. The remedy should not be monitored in a vacuum.
Response # 14 discusses botential pesticide sources unrelated to the Site. Without evidence to
shaw that other sources Jxist, the Agencies do not accept the contributions of any other sources I
to the creeks or groundwater. The Agencies know of no other potential source of pesticide
contamination which coJld significantly affect the groundwater or surface waters as the Geigy
Chemical Site has done. The Agencies also disagree with the idea that dilution estimates are
sufficient data to verify surf ace water quality. The Agencies disagree with the statement that
"direct surface water an~ sediment monitoring of Aberdeen Creek is not an appropriate means
of evaluating potentidl site-related risks resulting from discharge of downgradient
groundwater". Surrogdte monitoring is not sufficient to verify surface water quality. The
Agencies cannot excludJ real surface water data at this point in the process. in order to make
the best decision about I the remedy to be used in the cleanup process we must have all the
applicable data available.
Response:
Please see general comment response 4.
Specific Comment No. 81 .
Re!ponse #17 -it shoul~ be noted that while the baseline scenario (no adsorption and no decay) I is a conservative scenario with respect to evaluating the potential impacts on surface water, it is
not a conservative sceJario with respect to evaluating the mass reduction rate in the Lawer I
Black Creek Aquifer. 1j adsorption (retardation) of the pesticides is actually occurring in the
aquifer, the mass removhl rate will be less than that defined by the baseline scenario.
Response:
The baseline scenario was considered to be the most conservative approach to address potential
surface water exposureJ and thus the most protective basis for evaluating the remedy. Future
monitoring results will Ile used to periodically update the transport model and evaluate the effects I
of adsorption of pesticides to aquifer formation materials.
I Specific Comment No. 9:
13 May 1997
~ • RESPONSE TO USEPA COMMENTS
DA TED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
The Agencies agree witli response #19 which states that transport modeling is a management
tool to assist in the evalJation of the known data and to make decisions about the remedy. The
model however should nJ1 replace real data in the decision process.
Response:
The Companies agree and will conduct monitoring at the additional locations and increased
frequencies requested ~YI the Agencies (see general comment response 4) to provide data needed
to support remedy decisions.
I Specific Comment No. I 0
Response #20 -The resiilts of the non-baseline scenarios should be included in the RAWP so as
I .
to reflect the range of likely potential outcomes. However, it is recommended that all reference
to the half-life calculat1d with the MW-IID data (J.5 years) as being the "site-specific" or
"conservative" degraJtion rate be removed from the document. As the original cpmment
indicates, referring to /this degradation rate as being "site-specific" or "conservative" is
misleading since the technical basis used to calcula,te the half-life is groundless."
Response:
The non-baseline scenarios will be included in the RA WP. Reference to the Site-specific
degradation rate will be beleted from the document.
I Specific Comment No. 11
Response #36 -The grJundwater flow velocities presented in this report to Justify the proposed
frequency of monitorini are based on a very simplistic model of the aquifer system. Because of
the great uncertainties ~ssociated with groundwater flow and contaminant fate at the site, as well
as the uncertainties as~ociated with seasonal variations, sampling techniques, and analytical
techniques, the samplink frequency should be revised per the original comment.
Response:
Please see general comment responses I and 4.
14 May 1997
I • •
Specific Comment No. 12
RESPONSE TO USEPA COMMENTS
DA TED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
Response #37 -EPA disdgrees with the statement that "sampling results show that BHC isomers
have the capacity to de'w,ade under site-specific conditions". As indicated previously, the
analysis performed to cdlculate a half-life for the pesticide is flawed There has been no data
collected to date which ~ndicate that the pesticides are degrading. Until further studies are
conducted to evaluate thk potential degradation processes, dilution and dispersion are the only
processes which can b~ counted on to decrease the contaminant concentrations in the I downgradient groundwater.
Response:
The third paragraph on page 7-2 of the Draft RAWP (original subject of specific comment 37)
will be revised to read: "Modeling results indicate that naturally occurring Site conditions have
the capacity to attenuate concentrations of BHC isomers in the downgradient area to levels below
proposed Performance Standards under a wide range of conditions. Monitoring will be
conducted to verify modeled concentration trends and refine estimated attenuation rates."
Specific Comment No. 13
Comment #42 is addresking the failure of the proposed downgradient pump and treat system in
I the Upper and Lower Black Creek aquifer to contain the containment plume south of MW-2D.
The pump and treat rehieiry must contain the entire plume to prevent continued discharge of
contaminants to the suJounding creeks. Please revise the pump and treat to include the entire
contaminant plume.
Response:
Please see specific comment response 3.
. . I
Specific Comment No. ,14
Comment #43 discussek monitoring and actions to be taken if the NC Groundwater Standards I are exceeded at Municipal Water Supply Well Number 2. The NCAC Title 15A Subchapter 2L
Section . 0106(k)(4) reJuires thalthe Groundwater Standards "be met at a location no closer
than one year time of/(groundwater) travel upgradient of an existing or foreseeable receptor,
based on travel time and the natural attenuation capacity" of the contaminants. This condition I
must be demonstrated for Town Well Number 2 and documented in the RA WP before its
15 May 1997
I • • RESPONSE TO USEPA COMMENTS
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
finalized A monitoring well with acceptable concentrations does not exist in the area between
the estimated boundary of the plume and Town Well No. 2. Modeling along with one or more
properly placed monitor\ng well(s) to verify the model results should be sufficient.
Proper response actiojs should be documented with this Section of the RA WP and in the
Operations and Maintdnance Plan for conditions that are within a one year time of travel
upgradient of the pluJe. The supplemental monitoring at Town Well No. 2 should also be I accomplished as indicated in the plans.
Response:
See general comment response 4 regarding the installation of a sentinel well (MW-36L) for Town
Well No. 2. General rJsponse actions which will be implemented if pesticides are detected in the
sentinel well at concehtrations above proposed Perfonnance Standards are provided in the
decision tree, attached!. Specific response actions will depend on the nature and extent of
potential pesticide migr~tion to Town Well No. 2, as well as results of supplemental monitoring of I potable water at the well head. Specific response actions will be coordinated with the Town of
Aberdeen and the Age~cies.
Specific Comment No. 15
Response #48 -Again,/ because of the great uncertainties associated with groundwater flow and
contaminant fate at the Site, the monitoring plan should be revised per the original comment to I verify that the remedy is and remains protective of human health and the environment.
I
Response #48 states that potentiometric data indicates that these locations will not experience
increases in pesticide~ over time. The Agencies disagree with this statement especially for I monitoring well MW-25D. The companies often make emphatic statements based on modeled
assumptions. All _askmptions must be verified with real data. After a years consecutive
monitoring for verific~tion that pesticide concentrations in MW-19D and MW-25D continue to
decrease, monitoring ~~ be reduced at that time to a frequency that the Agencies determine to I be appropriate (possibly the 5 year review period).
I Monitoring of MW-20D and MW-23D will be required on an annual basis and during 5-year
review periods as a Jinimum to aid in determining the effectiveness of the remedy. Monitoring
16 M~l997
I • • RESPONSE TO USEPA COMMENTS
DATED FEBRUARY 19, 1997 ON THE
DRAFT DOWNGRADIENT REMEDIAL
ACTION WORK PLAN
of PZ-3 and PZ-4 should be included at least on an annual basis and at the 5 year review
periods.
A monitoring well should be installed to replace the destroyed PZ-4 monitoring point. This I
inner plume sampling location is critical for verifying the accuracy of the modeled plume
calibration and to aid ~n the management decision making process. At some point it may I
become necessary to add additional inner plume monitoring points to verify the concentrations
and extent of plume.
Response:
Please see general comment response 4. Wells MW-19D, MW-25D, MW-20D, MW-23D, PZ-3 I
and the replacement foriPZ-4 are components of the limited action alternative monitoring plan.
The need to install additional monitoring wells to verify the concentrations and extent of
downgradient pesticid~s will be assessed during periodic remedy review meetings with the
Agencies.
Specific Comment No. 16
I Comment #52 addressed comprehensive surface water monitoring. Please include the I
monitoring points SW0 l, SW-7, and SW-9 and additional monitoring in Aberdeen Creek as
indicated above.
Response:
Please see general comment response 4.
17 May 1997
Additional down-stream
monitoring point to be
located following field
reconnaissance.
N
Legend
c::::::J Pond
~ Swamp
c::::::J Building
/V Paved Roads
, ,, Unpaved Roads
-,-• -i Wooded Area
/V Railroads
/V Stream
~ US EPA
Monitoring Well/Piezometer
EB Monitoring Well
Lower Black Creek Aquifer
0 Monitoring Well
Upper Black Creek Aquifer
•
• •
s
~
0
e
Town of Aberdeen Municipal Well
Piezometer Nest
Lower Black Creek Aquifer
Monitoring Well Cluster
Upper/ Lower Black Creek Aquifer
Surface Water/ Sediment Sampling Location
Sentinel Well
•
Existing well or surface water/ sediment
sampling location included in Drah RAWP
monitoring plan.
Additional well or surface water/ sediment
monitoring location requested by Agencies,
with proposed modifications or supplemental
notes shown in text Boxes. Proposed well
identification shown in arentheses.
800 0 800 1600 ~-------
0 1 4
RIKr
Rust Environment & Infrastructure
SCALE IN FEET
1 2
SCALE IN MILES
FIGURE 1
DOWNGRADIENT REMEDIAL ACTION
PROPOSED MONITORING LOCATIONS
GEIGY CHEMICAL CORPORATION SITE
ABERDEEN NORTH CAROLINA
34
•
N
Legend
C::J Pond (D
r:-:---.:J Swamp + c::::::::J Building -¼-/'v' Paved Roads
, ,, Unpaved Roads • ~ Wooded Area 51 ./'Y' Railroads
/V Stream ~
(j US EPA i:=:J Monitoring Well/Piezometer ,.,,..,,, • USGS Well Cluster
Monitoring Well
Lower Black Creek Aquifer
Town of Aberdeen Municipal Well
Town of Aberdeen Municipal Well
(Abandoned I
Piezometer Nest
Lower Black Creek Aquifer
Monitoring Well Cluster
Upper/ Lower Black Creek Aquifer
Stream Staff Gauge
Simulated Capture Zone
for Town Well No.2 at 30 Gpm
54 Gpm Transient Aun for One Day
-,o-Total BHC Concentration µg/L
(Dashed where inferred)
0
RIKf
800 0 800 1600 ~----------
l 4
SCALE IN FEET
l 2
SCALE IN MILES
34
DRAFT
16-MAY-1997
FIGURE 2
SIMULATED CAPTURE ZONES FOR
MUNICIPAL WATER SUPPLY WELL NUMBER 2
IN THE LOWER BLACK CREEK AQUIFER
Rust Environment & Infrastructure
GEIGY CHEMICAL CORPORATION SITE
ABERDEEN NORTH CAROLINA
SW/SED 2
SW/SED 3
SW/SED 2
SW/SED 3
SW/SED 7
• TABLE I
SUMMARY OF PREDICTED HUMAN HEALTH RISKS I
ACROSS ALL PATHWAYS FOR EACH SAMPLE LOCATION
GEIGY CHEMICAL CORPORATION SITE
A. Potential Carcinogenic Risks (Excess Lifetime Cancer Risks)
I
2E-08 4E-l l 3E-11
2E-08
Bj Potential Non-Carcinogenic Risks (Hazard Index)
I
2E-04 6E-07 4E-07
9E-05
9E-07 6E-07
I
(a) Only locations at which chemicals were detected are listed.
I
Pathway not complete at this location; no chemicals detected.
2E-08
2E-08
2E-04
IE-04
2E-06
• TABLE2
RISK-BASED CONCENTRATIONS FOR SURFACE WATER
I
BASED ON LONG-TERM EXPOSURES IN HUMANS
GEIGY CHEMICAL CORPORATION SITE
alpha-BHC I 3.5 35 350 8
beta-BHC I 12 120 1200 8
I gamma-BHG: 17
I
170 1700 0.4
delta-BHC I 93 930 · 2800 8
(a) Human healthlrisk based concentrations are presented for the risk range identified in USEPA Region IV guidance:
excess lifetime 1cancer risks in the range of IO~ to IO~ for potential carcinogen, and hazard indices in the range ofO. I , I. to 3 ,or noncarcmogens. The RBCs for delta-BHC are based on potential noncarcinogenic effects; each of the others
is based on po ential carcinogenic effects.
• TABLE3
SUMMARY OF DILUTION FACTOR CALCULATIONS
GEIGY CHEMICAL CORPORATION SITE
Estimated Stream Estimated
Flow Rate Groundwater
(see note I) Discharge Rate
Stream Drainage cfs gpm (gpm)
I
,rea (mi2
)
McFarland's I 0.5 0.65 290 50
Branch (see note 2)
I
Ray's Mill Creek I 5 7 3000 100
(see note 3) I
Aberdeen Creek I 14 20 9000 180
(see note 3)
I
Notes: I
1. Calculated as proportion based on stream gauge data at mouth of Aberdeen Creek:
Average Flow Rate (!auging station 0213357100) = 51 cfs
Drainage Area= 37.8 rm
where:
37.8 mi' =
DA
DA =
50 cfs
X
Drainage area of stream(~
x average stream flow rate ( cfs)
Stream gauge data and calculation method provided by Curtis Weaver, USGS, 3/20/96.
2. Drainage area calculated at n\outh of creek based on topographic data.
Calculated
Dilution Factor
6
(see note 4)
30
50
I .
3. Drainage area provided by Curtis Weaver, USGS, 3/20/96. Drainage area calculated at mouth of creek and at Pages Lake for Ray's
Mill Creek and Aberdeen Creel respectively.
I
4. Dilution factor for McFarlarld Branch reduced to 2.3 based on estimated groundwater and measured surface water concentrations.
•
TABLE4
BHC ISOMER DEGRADATION PRODUCTS
Chlorobenzene
Dichlorocyclohexadientriol
2,4-Dichloroplienol
I
2,4-Dichlorothiophenol
I Hexachlorobenzene
Hydroxydichlo~othiophenol
m-Dichlorobenh:ne
o-Dichlorobeniene
p-Dichlorobeniene I Pentachloro-2-cyclohexen-l-ol I Pentachlorobenzene
I
Pentachlorocyclohexene
I
Pentachlorocyclohexenol
I Pentachlorophenol
I
1,2,3, 4-Tetrachlorobenzene
I 1,2,3 ,5-Tetrachlorobenzene
I
1,2, 4 ,5-Tetrachlorobenzene I Tetrachlorophenol
I
2,3,4,5-Tetrachlorophenol
2,3 ,5, 6-Tetrachlorophenol
Tetrachlorocyclohexene
Tetrachlorocyclohexenol
2,3,4,6-Tetrachloro-2-cyclohexen-I -ol
2,4,5,6-Tetrachloro-2-cyclohexen-l-ol
1,2,3-Trichlorobenzene
1,2,4-Trichlorobenzene
1,3,5-Trichlorobenzene
2, 4 ,5-T richlorobenzene
(36/45)-4,5,6-trichlorocyclohexen-3-ol
Trichlorocyclohexadientriol
Trichlorothiophenol
2,3,5-Trichlorophenol
2,3,6-Trichlorophenol
2,4,5-Trichlorophenol
2,4,6-Trichlorophenol
3,4,5-Trichlorophenol
•
TABLE5
ORAU TOXICITY VALVES OF BHC ISOMERS AND DEGRADATION PRODUCTS
I
BHC Isomen
alpha-BHC
bea-BHC
dclta-BHC
gamrna-BHC 0.0003 IRIS
IRIS
IRIS
IRIS
Degradation Products
ChJorobenzenc
DichJorocyclohcx.ad ientriol
2,4-Dichlorophenol
2,4-Oichlorothiophenol
Hcxachlorobenzenc
Hydroxydichlorothiophenol
m-Dichlorobcnzenc
o-Dichlorobenzenc
~Dichlorobenzenc
Pcntachloro-2-cyclohcxen-l-.
Pentachlorobenzene
Pentachlorocyclohcxenc
Pentachlorocyclohcxenol
Pentachlorophenol
0.02
0.003
0.0008
0.089
0.09
EPA Region 3
1,2,3 ,4-T ctrachlorobenzenc
1,2,3,.5-T ctrachlorobcnzenc
1,2, 4,.5-T ctrachlorobenzenc
Tctrachlorophenol
2,3 ,4, .5-T ctrachlorophenol
2,3, 5 ,6-T ctrachlorophenol
Tctrachlorocyclohcxenc
Tctrachlorocyclohcxenol
2,3,4,6-T ctrachl~ 2-cyclohc:
2,4,.5,6-Tctrachloro-2-cyclohc
1,2,3-Trichlorobcnzenc
1,2, 4-Trichlorobenzenc
1,3,5-T richlorobenzenc
2,4,.5-T richlorobenzenc
(3 6/4 5 }-4,.5 ,6-trichlorocyclohc
Trichlorocyclohcxadientriol
Trichlorothiophenol
2,3,.5-Trichlorophenol
2,3,6-Trichlorophenol
2,4,5-Trichlorophenol
2,4,6-Trichlorophcnol
3,4,S-Trichlorophenol
NOlES:
-= No information available,
0.0008
O.oJ
0.0003
0.03
0.01
0.1
NA = Not applicable. Chroruc to,uc1ty value available.
HEAST • Health Effects summary Table. USEPA (199Sb).
IRIS
IRIS
IRIS
IRIS
IRIS
IRIS
IRIS
IRJS., Integrated Risk InfonnatiOtl System USEPA (1997).
RTECS• Registry ofToxic Effec:J of Chemical Substances, 1997.
Sax 1994"' Dangerous Properties bftndu.wial Materials, 8th Edition.
USEPA .. U.S. Environmental Pr~tcction Agency.
EPA Region III., Risk-Based Coricentration Table. USEPA (1996)
I
(a) A mouse intrapcritoncal LD50 is listed because no oral LD50 value is available.
(b) A mouse oral LD50 is listed bcca~e no rat value is available.
6.3E<-O0
1.8E<-O0
l.3E+O0
l.6E+00
0.024
0.12
I.IE-02
IRIS
IRIS
IIEAST
IRIS
IIEAST
IRIS
IRIS
177
6,000
1,000
76
NA
NA
NA
NA
NA
NA
2,930
NA
1,167
1,727
NA
140
400 (b)
NA
1390 (•)
NA
800
308
NA
NA
Sax 1994
Sax 1994
Sax 1994
Sax 1994
NA
NA
NA
NA
NA
NA
RTECS
NA
Sax 1994
Sax 1994
NA
Sax 1994
Sax 1994
NA
Sax 1994
NA
Sax 1994
Sax 1994
NA
NA
•
TABLE6
USEPA ANALYTICAL METHOD AVAILABILITY AND QUANTITATION
I LIMITS FOR BHC ISOMER DAUGHTER PRODUCTS
Chlorobenzcne I
Dichlorocyclohexadientriol
,4-Dichlorophenol
,4-Dichlorothiophenol
Hexachlorobenzcne
Hydroxydichlorothiophlol
m-Dichlorobenzene
o-Dicblorobcnzene
p-Dichlorobenzene
Pentachloro-2-cyclohexei-l-ol
Pentachlorobenzene
Pentachlorocyclohexene
Pcntachlorocyclohexenol
Pentachlorophenol
I .2 ,3 ,4-T etrach lorobenzene
I 1,2,3 ,5-T etrachlorobenzene
I 1.2,4,5-T etrachlorobenzcrie
etrachlorophenol I
2,3,4 ,5-T etrachlorophenol
2 ,3 ,5 ,6-T etrachlorophenoi
Tctrachlorocyclohexene I
T etrachlorocyclohexenol
,3 ,4 ,6-T etrachloro-, 2-cyclohcxen-l -ol
2,4,5,6-T etrachloro-2-cycl1ohexen-l-ol
1,2,3-Trichlorobcnzene
1,2,4-T richlorobenzenc
1,3,5-T richlorobenzenc
,4,5-Trichlorobcnzene
(36/45)-4,5,6-trichlorocyclohexen-3-ol
richlorocyclohexadientri 11
Trichlorothiophenol
,3,5-T richlorophenol
,3,6-Trichlorophenol
.4.5-Trichlorophenol
,4,6-Trichlorophenol
3,4,5-Trichlorophenol
Notes: I
108-90-7
120-83-2
1122-41-4
I 18-74-1
541-73-1
95-50-1
106-46-7
608-93-5
3 I 9-94-8
87-86-5
634-66-2
634-90-2
95-94-3
25167-83-3
4901-51-3
58-90-2
1782.00-9
78137-68-5
78137-69-6
87-61-6
120-82-1
108-70-3
27941-98-6
993-78-8
933-75-5
95-95-4
88.06-2
57730-96-8
X
X
X
X
X
X
X
X
X
X
X
-• USEPA analytical method not available.
X = USEPA analytical method available.
EMMI = Environmental M6nitoring Methods Index Database. USEPA (1995a).
TCL CRQL • Target Compound List Contract Required Quantitation Limit. USEPA (1994b).
I
5
10
20
0.3 (a)
10
25
10
(a) Value based upon USE~A Test Methods for Evaluating Solid Wastes (SW-846) recommended methodology
for converting a selected Method Detection Limit (MDL) to a Practical Quantitation Limit (PQL) by
multiplying by a factor rif 10 (USEPA 1994a).
TCLCRQL
TCLCRQL
TCLCRQL
TCLCRQL
TCLCRQL
TCLCRQL
TCLCRQL
EMMI
TCLCRQL
TCLCRQL
TCLCRQL
• • TABLE7
SURFACE WATER INGESTION
EXPOSURE AND TOXICITY ASSUMPTIONS
GEIGY CHEMICAL CORPORATION SITE
cw
IR
EF
ED
CF
Bio
BW
AT
--~ I . = Sw,ace Water Concentrabon (mg/L)
I
Ingestion Rate ( ml)day)
I
I = Exposure Frequency ( days/year)
I
= Exposure Duratiod (years)
I
= Conversion factor I
I = Bioavailability Factor (unitless)
I
Body Weight (kg) I
. I Average Tune (days)
= ED • 365 days/yea¼ for noncarcinogens
= 70 yr • 365 daysty.!.r for carcinogens
I
RID= I
Refer.ence Dose forl delta-BHC
CSF = Cancer Slope Factor
alpha-BHC
beta-BHC
ganuna-BHC
chemical-specific
52
IE-3 Uml
1.0
45
3,650
25,550
0.0003 mg/kg-day
6.3 (mg/kg-day)1
1.8 (mg/kg-day)1
1.3 (mg/kg-day)'
Site sampling data
USEPA Region IV (1995) default value
Assumes 3 days/week during summer months
and I day/week during spring and fall
USEPA Region IV (I 995)
USEPA (1989) default value
USEPA Region IV (1995) default value
USEPA (I 989)
ganuna-BHC selected as surrogate; USEPA
(1996)
USEPA (1996)
U.S. Environmental ProtectionlAgency (USEPA). 1989. Risk Assessment Guidance for Superfund. Vohune I. Human Health I Evaluation Manual /Part A) Interim Final. Washington, DC: Office of Emergency and Remedial Response. EPA 540-1-89/002.
U.S. Environmental ProtectioJ Agency (USEPA). 1995. Supplemental Guidance to RAGS.
I
Region 4 Bulletins. Human Health Risk Assessment. Interim. November.
U.S. Environmental ProtectioJ Agency (USEPA). 1996. Integrated Risk Information System (IRIS). Cincinnati, OH:
Environmental Criteria and A~sessment Office.
SW-2
dplm-B S:20E::05
beta-BCH 8.SOE-05
gamma-BCH S.90E-OS
Tobi Excess Llfrtlme Cancer Risk
:nu alpha-BCH 4.40E-05
bda-BCH 5.SOE-05
gamma-BCH 3.SOE-05
Total Excess Ufedme Cancer Risk
SW-2
gamma-BCH 0000059
delta-BCH 0.00Cl097
Tobi Haunt Quotient
~
gamma-SCH 0.000035
delta-SCH 0.000061
Tobi Hanni Quotient
TABLES
POTENTIAL RISKS ASSOCIATID wmt lNCIDENTAL INGESTION
BY CIDlDREN OF CHEMICALS IN SURFACE WATER
GEIGY CHEMICAL CORPORATION SITE
LOO 6.30E+OO liver B2
LOO l.80E+OO liver C
LOO l .30E+OO liver B2-C
LOO 6.30E+OO liver B2
LOO I .80E+OO liver C
LOO I .30E+OO liver B2-C
LOO 3.00E-04 liver, kidm:y
LOO 3.00E-04 liver, kidney
LOO 3.00E-04 liver, kidney
1.00 3.00E-04 liver, kidney
(a) {L)ADD -(Ingestion rate mUd • Bio •exposure frequency days/yr• exposure duration )Totw!lter concentration mg/L •cFUmlY(iwcraging time yr•36Sd/yr"'body weight kg)
(b) USEPA Weight of Evidence for Carcinogenic Effects: (A]• Human Carcinogen, sufficient evidence from human epidemiological studies;
(82] • Probable Human Carcinogen, inadequate or no evidence from epidemiological studies 811d adequatt: evidence from animal studies;
(CJ -Possible Human Carcinogen, limited evidence in animals in the absence of human data. [DJ= Not classified as to human carcinogenicity.
2.3SE-10 l.48E-09
3.84E-10 6.92E-IO • 2.67E-IO J.47E-IO
2.52E-09
l.99E-IO l.25E-09
2.49E-IO
l.58E-10
l.91E-09
1.87E-09 6.23E-06
3.07E-09 l.02E-05
1.65E-OS
1.IIE-09 l69E-06
l.93E-09 6.44E-06
I.OIE-05
•
GEIGY CHEMICAL CORPORATION SITE
DOWNGRADIENT REMEDY DECISION TREE
ATTACHMENT 1
LIMITED ACTION ALTERNATIVE MONITORING
Monitoring points Lll be in accordance with the sample locations shown on Figure I.
Sample frequencies1 are described in the RA WP and decision tree. The need to revise
monitoring locationk will be assessed during remedy review meetings.
• Groundwater sJmples collected during the first year (i.e., first four quarterly sampling
efforts) will be I analyzed for TCL pesticides using EPA method 8081 ( or current
promulgated equivalent), including heptachlor and heptachlor epoxide per
NCDEHNR' s r~quest. Results of these sampling efforts will be reviewed with the
Agencies at th~ end of the -first year and used to develop a parameter list for
subsequent sampling events. Potential parameters for subsequent analyses will be
screened by calc,ulating the geometric mean concentration of individual TCL pesticides
at each monitoring well over the four quarterly sampling events. Constituents with
mean concentdtions greater than the threshold values listed in Table I will be• ' reviewed with the Agencies to determine if they should be included in subsequent
groundwater mbnitoring events. Information used to develop the groundwater
monitoring par~meter list will include the location and frequency of detects,
concentration tr~nds, and difference between mean concentration and threshold values.
Based on all infilrmation to date, the parameter list is anticipated to be .alpha-, beta-,
I delta-and gamma-BHC.
• Surface water Jd stream sediment samples collected during the baseline event will be
analyzed for alpha-, beta-, delta-and gamma-BHC, heptachlor, and heptachlor epoxide
using EPA method 8081 (or current promulgated equivalent). Heptachlor and/or
heptachlor epoxitle will be deleted from subsequent analyses if the mean groundwater
' concentrations of these constituents from the baseline event are below their associated
MCL (0.4 ug/1 arid 0.2 ug/1, respectively) (see Table I).
• Confirmation sJmples will be collected and analyzed in the event pesticide
concentrations iri a stream surface water or sediment sample exceed risk-based levels
determined to be protective of potential human or ecologic receptors.
• Supplemental monitoring of Town Well No. 2 will be coordinated with the Town of
Aberdeen during I each groundwater monitoring event. Samples will be analyzed for
drinking water series pesticides using EPA methods 505 and 508.
• In the event thaJ a supplemental sample result is found to exceed 50% of a given
drinking water st~ndard, Town Well No. 2 will be resampled on a rush basis. If the
sample confirms I pesticide levels are greater than 50% of a given drinking water
standard, supplemental sampling will increase to a monthly basis to further assist
I
•
monitoring of: well-head pesticide concentration trends and prevent potential
exposures thrciugh the implementation of corrective measures, where appropriate.
When two s~ccessive months of supplemental sampling indicate that the
concentrations \ have again dropped to below 50% of the given drinking water
standards, supplemental sampling will be conducted on the same frequency as
groundwater monitoring samples.
• Visual surveillLce will be conducted during each routine monitoring event to
determine if ne\i/ residential wells have been installed in the downgradient area.
• Surface water Ld sediment samples will be collected from McFarland's Branch,
Aberdeen Creek and Ray's Mill Creek during the initial sampling event to document
baseline conditibns. Sampling in Aberdeen Creek and Ray's Mill Creek will be
conducted there1after only if trigger levels in sentinel groundwater monitoring wells ' MW-32L, MW-38L and MW-39L are exceeded. Trigger levels are provided in Table
2 of Attachment\!. Sentinel wells MW-32L, MW-38L, and MW-39L will be screened
across the entire saturated thickness of the aquifer.
2
•
TABLE 1
PROPOSED GROUNDWATER MONITORING THRESHOLD CONCENTRATIONS
I
TCL Pesticide
I
Monitoring Threshold Concentration (ug/L)
Existing Performance MCL 1
Standard
aldrin 0.05
aloha-BHC I 0.05
beta-BHC I 0.05
delta-BHC I 0.05
l!amma-BHC I 0.05 0.2
Chlordane I .. 2
dieldrin I 0.1
endrin I 2
endrin ketone I 0.1
heotachlor I 0.4 ' ' heotachlor eooxide ' 0.2 1
methoxvclor 40
toxaohene 1 3 <
I 1 Proposed thresholo value based on Federal MCL.
3
Compound
Alpha-BHC
Beta-BHC
Delta-BHC
TABLE 2
TRIGGER LEVELS FOR RAY'S MILL CREEK AND ABERDEEN CREEK
SURFACE WATER/SEDIMENT SAMPLING
Ray's Mill Creek Aberdeen Creek
Risk-Based In Stream Trigger Level In-Stream Trigger Level
Concentration Concentration in Groundwater Concentration in Groundwater
for Surface Correction (ug/1)3 Correction (ug/1)3
Water (ui:~/1)1 Factor2 Factor2
3.5 15 53 25 88
8 15 120 25 200
8 15 120 25 200
Gamma-BHC 0.4 15 6 25 10
Notes:
1 Lower of the human health or ecological risk-based concentration for surface water.
2 Calculated as one-half the dilution factor for Ray's Mill Creek (30) and Aberdeen Creek (50); dilution factor
will be verified and revised if necessary based on measured surface water/groundwater concentrations.
3 Calculated as the risk-based concentration in surface water times the in-stream concentration correction factor.
Surface water and sediment to be sampled in Ray's Mill Creek and Aberdeen Creek following baseline event
only if associated trigger levels in sentinel wells are exceeded. Sentinel wells are MW-32L and MW-38L for
Aberdeen Creek, and MW-39L for Ray's Mill Creek.
4
•
•
GEIGY CHEMICAL CORPORATION SITE
DOWNGRADIENT REMEDY DECISION TREE
ATTACHMENT 2
DATA DEVELOPMENT
• Monitoring results will be reported to the Agencies after each sampling event,
following data ~alidation and review by the Companies.
• Data will be coipiled into annual monitoring reports which will include:
* Graphical c~mparison of individual monitoring well pesticide concentration trends
to predicted trends; Recalibrate transport model and provide updated transport ' simulations, if necessary;
* Graphical pr~sentation of pesticide mass reduction trendsfor the Upper and Lower
Black Creek \aquifers; .
• Revised gamma-BHC isoconcentration maps for the Upper and Lower Black
Creek aquife}s;
• Revised potehtiometric maps for the Upper and Lower Black Creek aquifers;
• Graphical c~mparison of stream surface water and sediment pesticide
concentratio~
1
trends to risk-based levels determined to be protective of potential
human and ecologic receptors; and
• Identification \of data outliers through graphical and/or statistical analysis.
• Graphical comparison of pesticide analytical results in sentinel wells MW-32L, ' MW-38L, and MW-39L to trigger levels.
• Annual monitori~g reports will comment on the appropriateness of sampling
frequencies, analytical parameters and methods, and media. Recommendations for any
' modifications of future monitoring events will be included for review and discussion
with the Agencies.I
5
•
GEIGY CHEMICAL CORPORATION SITE
DOWNGRADIENT REMEDY DECISION TREE
ATTACHMENT 3
REMEDY EVALUATION
Groundwater ·
• Performance o~ the limited action alternative will be evaluated independently for the
Upper and Lower Black Creek aquifers.
• Groundwater lonitoring results will be compared with the following proposed
performance stahdards for the downgradient area:
I Compo
1
und
alpha-BHC
I beta-BHC
I delta-BHC
I
Proposed Performance Standard (ug/L)
0.05
0.05
0.05
0.2 · gamma-BHC
• Monitoring data L11 be evaluated to determine if:
• The reme1dy continues to be protective of human health and the environment;
• Former ~ource areas are hydraulically isolated by the facility property I . groundwater extraction and treatment system;
• Overall p~sticide concentrations within each aquifer are declining;"
• The areal 1extent of pesticides within each aquifer is declining; and
• The Site iroundwater flow and transport models need to be refined.
• Groundwater coJentration and mass reduction trends will be graphically evaluated
following the pro~edures described in Section H. 4. I of the RA WP.
Stream Surface wa.lr/Sediment
• Surface water Jd sediments in Aberdeen Creek and Ray's Mill Creek will be
resampled if grouhdwater concentrations in the sentinel wells exceed trigger levels.
Monitoring data \will be compared against risk-based levels determined to be
protective for long-term exposures. In the event transient increases in pesticide
concentrations occur above long-term levels, short-term risk-based levels will be
developed and used to evaluate the need for potential corrective measures.
6
Drinking Water
Town Well No. 2
•
• Town Well No. 2 supplemental monitoring results will be compared against MCLs.
Sentinel Well
• Sentinel well -36L) monitoring results will be compared against MCLs.
7
•
GEIGY CHEMICAL CORPORATION SITE
DOWNGRADIENT REMEDY DECISION TREE
ATTACHMENT 4
GROUNDWATER PERFORMANCE STANDARDS COMPLIANCE EVALUATION
• Attainment of koundwater performance standards will be independently evaluated for
the Upper and Lower Black Creek aquifers.
0 Attainment of groundwater performance standards will be evaluated by preparing
concentration trend graphs for visual comparison against associated performance
standards.
8
•
GEIGY CHEMICAL CORPORATION SITE
DOWNGRADIENT REMEDY DECISION TREE
ATTACHMENT 5
POST ATTAINMENT REMEDY REVIEW
• Post-attainment monitoring data will be reviewed with the Agencies following
verification that groundwater performance standards have been achieved.
• Post-attainment monitoring will be conducted independently in the Upper and Lower
Black Creek aquifers for a minimum consecutive period of five years.
• Attainment of Jroundwater performance standards will be verified by conducting a
one-tailed t-testl at the 95 percent confidence level between the average observed
concentration at a given well and the groundwater performance standard.
• Monitoring of the Upper and/or Lower Black Creek aquifers may be independently
terminated.
9
•
ATTACHMENT A
BHC DEGRADATION
AND IMPLICATIONS FOR MONITORING
AT THE GEIGY CHEMICAL CORPORATION SITE
BHC isomers have been detected at low part per billion (ppb) concentrations in the groundwater
beneath the Geigy Ch1emical Corporation Site in Aberdeen, North Carolina. Olin Corporation,
' Novartis Crop Protection Inc., and Kaiser Aluminum & Chemical Corporation (the Companies),
in conjunction with th~ U.S. Environmental Protection Agency (USEPA) and the State of North
Carolina have propose~ a limited action alternative for the site that consists of source control and
downgradient monitoring The Companies have proposed that the downgradient monitoring for
the site focus on me~surement of concentrations of BHC isomers. During recent meetings
between the Companicis, USEP A, and the State, inclusion of BHC degradation products into the
' downgradient monitoring program has been discussed.
I
To address the feasibility and necessity of this approach, the Companies conducted an exhaustive
literature search to identify information on BHC degradation, daughter product analytical
chemistry, and daughter product toxicity. More than 25 on-line databases and secondary
publications were utiliied to identify pertinent literature. From the initial list of relevant .articles,
we identified approxirilately 30 key citations for detailed review. This paper summarizes the
results of our review land then discusses the implications of these findings .for groundwater
monitoring at the Geigy site. A complete list of the literature reviewed is presented at the end of
this document. I
BBC DEGRADATION
Numerous studies hat been conducted to address the processes and products of BHC
degradation. Most of these studies have been conducted using relatively high concentrations of
BHC isomers in the pJrent medium (e.g., generally on the order of 2 parts per million [ppm]),
compared to the levels\ detected at the Geigy site. The use of ppm level concentrations in the
parent medium increases the likelihood that daughter products will be present at analytically
detectable levels. ·
Table A-1 lists the BHCC degradation products identified in the literature. As can be seen, more
than 30 products have b1een identified. These chemicals can be formed as a result of chemical and
biological processes. In1 general, two principal degradation pathways exist. One basically follows
a reductive dehalogenation process and proceeds as follows: BHC ➔ pentachlorocyclohexene
(PCCH) or tetrachlor6cyclohexene (TCCH) ➔ tetrachlorobenzene ➔ trichlorobenzene ➔
monochlorobenzenes, Jnd eventually, CO2 + H20 + HCI. The other basically follows a
A-1
•
ATTACHMENT A
hydroxylation process, that results in the formation of chlorophenols, which themselves undergo
reductive dehalogenation to eventually produce chloroacetic acid, and finally CO2 + H20 + HCI.
Chemical Degradatio1 Processes -
I
The primary chemical mechanism of BHC degradation is hydrolysis, during which a water
molecule reacts with a\chlorine atom on the cyclohexane ring. The hydrolysis of alpha-BHC and
gamma-BHC occurs by trans-dehydrochlorination of the axial chlorines resulting in the formation
of the intermediate coriipound PCCH and HCI. PCCH reacts further with either H20 or OH and ' undergoes a sequential dehydrochlorination to produce a mixture of the regioisomers, 1,2,3-,
trichlorobenzene and 1,2,4-trichlorobenzene (Sharom et al. 1980; USEPA 1993; Alexander
1994). The trichlorobtinzenes are stable with respect to hydrolysis, but are susceptible to other
abiotic degradation pr9cesses such as hydroxylation. The only other product from this set of
reactions is HCl, which is indistinguishable from naturally occurring chloride ion in the
environment. Hydroly1sis of BHC follows 1st order kinetics. Hydrolysis rate constants are
moderate at a pH of s,I negligible at pHs of 7.3 to 7.8, and greatest at a pH of 9 (Saleh et al.
1982). Beta-BHC is thb only BHC isomer that does not hydrolyze to any significant extent. This
is principally because the 6 equatorial chlorines on this isomer do not permit initial trans-
' dehydrochlorination to RCCH, as occurs in the other isomers (USEPA 1993).
BHC isomers may also be transported from soil and groundwater through volatilization. The
process of volatilization involves the transformation to PCCH, diffusion of PCCH upwards
towards surface soils, arid ultimately PCCH volatilization into the atmosphere, where it is rapidly
oxidized (Cliath and S~encer 1972; Alexander 1994). Approximately 2/3 to 3/4 of lindane
applied in field studies vi>latilized in the form of PCCH, based upon a vapor pressure for PCCH, I
which is approximately p times greater than that of lindane at 30°C (Cliath and Spencer 1972;
Samuel and Pillai 1990; Waliszewski 1993). Volatilization ofBHC isomers and PCCH increases
linearly with increasing \temperature. A six-fold increase in PCCH was demonstrated when
temperature was increased from l 5°C to 45°C (Cliath and Spencer, 1972; Samuel and Pillai,
1990). Volatilization alsb increased in flooded soils compared to nonflooded soils (Samuel and
Pillai, 1990). Although J
1
olatilization of BHC is documented, it is likely only to play a significant
role in near-surface groundwater (Zoeteman et al. 1980).
I .
Biological Degradation iocesses
BHC biodegradation occurs through both aerobic and anaerobic mechanisms. If environmental
conditions are appropriatb, both of these mechanisms may act in a single location (e.g., at the
groundwater capillary fiin1ge in shallow aquifer systems, such as the Upper Black Aquifer at the
Geigy site).
A-2
•
ATTACHMENT A
Aerobic degradation ofBHC isomers is extremely complex, but basically mimics human metabolic
processes. A variety\ of commonly found soil microbes and fungi, such as Pseudomonas and
Bacillus species, Enterobacteriacae, Clostridiae, and White rot fungus (Phanerochaete
chrysoporium) have bJen shown to readily degrade BHC under aerobic conditions (Kohnen et al.
1974; Tu 1976; Engst ~t al. 1977; Haider 1979; Kennedy et al. 1990; McTeman and Pereira 1991;
Sahu et al. 1993).
The primary product ,of aerobic microbial degradation is 2,3,4,5,6-PCCH. This product is
chemically unstable and is susceptible to reaction with naturally occurring organic materials (Yule I
et al. 1967; Haider 1919; Kennedy et al. 1990). PCCH is subsequently transformed into several
chlorinated benzenes and phenols by the elimination of HCI, or through chemical or biochemical
dehydrogenation and b~ the addition of water. During this dehydrogenation, small amounts of
hexa-and pentachlorotlenzenes are possibly formed. More prominent, however, are tetra-and
trichlorobenzenes and torresponding phenols (Tu 1976; Haider 1979; Kennedy et al. 1990).
Subsequent ,degradatiori products include chloroacetic acid, and ultimately, CO2, H20, and HCI
(Haider 1979; Sahu et \at. 1993). Some of the chlorinated benzenes also can be biologically
transformed to chlorophenols and chlorocatechols. These materials are biologically stable, but
they may undergo polyrilerization through an oxidative coupling mechanism or conversion to the
equivalent quinone.
Under anaerobic conditions, both strict and facultative anaerobes degrade BHC to the primary
product TCCH (Jagnow\et al. 1977; Adhya et al. 1995). Degradation under anaerobic conditions
is more rapid than the aerobic mechanism and proceeds primarily through a dehydrohalogenation
pathway that involves thlorinated cyclohexenes and chlorinated benzenes. Specifically, the
primary degradation \product TCCH is subsequently dechlorinated into benzene,
monochlorobenzene, and small amounts of tetra-and trichlorobenzenes (Jagnow et al. 1977; I
Haider 1979; Adhya et al. 1995). Again, some of these chlorinated benzenes can be biologically
transformed to chlorophJnols, chlorocatechols, and equivalent quinones.
Some of the intermediatJs, notably PCCH and TCCH, rapidly volatilize from soil and enter the
atmosphere where they ~re degraded by interaction with native hydroxyl radicals (Cliath and
Spencer 1972; Samuel Jnd Pillai 1990; Waliszewski 1993). Further, when anaerobic BHC
degradation processes o~cur, it is likely that subsequent organic products may be destroyed
aerobically. For example,\chlorinated benzenes that are generated anaerobically from BHC can be
transformed aerobically (Benezet and Matsumura 1973; Kohnen et al. 1974; Jagnow et al. 1977).
Such two-stage processek involving an initial anaerobic phase followed by a final aerobic phase
represent likely means for 1the mineralization ofBHC (Alexander 1994).
A-3
•
ATTACHMENT A
DETECTION OF DEGRADATION PRODUCTS
I
The majority of BHC degradation products cannot be detected with standard analytical
techniques. In fact, t~e majority of BHC degradation studies reported in the literature relied on
research-type analytidl methods to detect these compounds. Analytical methods have not been I
developed by USEPA for the majority of compounds. A!, shown in Table A-2, USEPA analytical
methods are available\ for only about one-third of the degradation products, and no standard
methods are available, for the two initial degradation products PCCH and TCCH. Thus,
measurement of BHC degradation in the groundwater at the Geigy site would be complicated by a
lack of detection limits !ror most of the compounds.
I
Detection of degradation products also would be complicated by the very low parent BHC
concentrations that cutrently exist in groundwater. Chemical and biological BHC degradation
processes act both sim~ltaneously and sequentially. For example, hydrolysis and biodegradation
will act on BHC isomJrs at the same time to produce different chemical intermediates. These
intermediates themselv~s will also be chemically and biologically transformed to produce still
other chemicals, some rif which act upon themselves. A!, a result, at any given time, there could
be several dozen reactibn products at a specific location. Because the initial concentrations of
BHCs are already low ~t the Geigy site, the concentrations of the daughter products will be even
lower, and are likely tb be below practical quantitation limits. Total BHC concentration in I
groundwater are generally in the range of IO µg/L or less. Degradation processes that lead to the
I • formation of more than 30 daughter products will produce concentrations well below these initial
starting levels. As can be seen from Table A-2, quantitation limits for the few daughter products
for which they exist, are 1\equal to or greater than the current parent compound concentrations.
DAUGHTER PRODUCT TOXICITY
BHC degradation prodjts are less toxic than the parent compound. In fact, BHC degradation
basically mimics human lnetabolic detoxification processes. Table A-3 presents chronic toxicity
values (or acute values, ~bsent chronic values) for BHC isomers and the daughter products. A!,
can be seen, the daughtei products are less toxic than the parent BHC isomers. In fact, PCCH is
nearly 40 times less toxic\ than the parent compound lindane. Similar relationships are apparent
for the other daughter lproducts. Thus, BHC degradation will reduce the toxicity of the
compounds present in grdundwater.
I
IMPLICATIONS FOR MONITORING AT THE GEIGY SITE
Based on this review, the\ Companies maintain that monitoring of parent BHC concentrations in
groundwater is an most \ appropriate and health protective approach for determining remedy
effectiveness at the Geigy site. The factors supporting this decision are:
A-4
•
•
•
ATTACHMENT A
The high number of BHC daughter products complicates monitoring and virtually
eliminates the ~ossibility that the monitoring results could be used to determine the degree
to which degra~ation has occurred.
Standard analtical methods have not been developed for the majority of daughter
products.
• The daughter products will be present at non-detectable concentrations.
• BHC degradatiln products are less toxic than the parent compound.
Given the significant dtree to which BHC degradation processes are understood, the decreased
toxicity of degradation \products, and the inherent practical limitations in monitoring degradation
products, the Companies believe that it is sufficient to monitor the disappearance of the parent
BHC compound to ensJre that public health is being protected.
A-5
•
TABLE A-1
BHC ISOMER DEGRADATION PRODUCTS
I Chlorobenzene
I
Dichlorocyclohexadientriol
I
2,4-Dichlorophenol
2,4-Dichloroiliiophenol I Hexachlorobenzene
Hydroxydichldrothiophenol
m-Dichloroberizene
o-Dichlorobenkne
p-Dichloroben±ene I Pentachloro-2-cyclohexen-l -ol
I Pentachlorobenzene
I Pentachlorocyclohexene
I
Pentachlorocyclohexenol I Pentachlorophenol
I 1,2,3, 4-Tetrachlorobenzene I 1,2,3 ,5-Tetrachlorobenzene
I 1,2, 4 ,5-Tetrachlorobenzene
I Tetrachlorophenol
I
2,3,4,5-Tetrachlorophenol
2,3,5,6-Tetrachlorophenol
Tetrachlorocyclohexene
Tetrachlorocyclohexenol
2,3, 4, 6-Tetrachloro-2-cyclohexen-l -ol
2, 4 ,5, 6-Tetrachloro-2-cyclohexen-l -ol
1,2,3-Trichlorobenzene
1,2,4-Trichlorobenzene
1,3,5-Trichlorobenzene
2,4,5-Trichlorobenzene
(36/45)-4,5,6-trichlorocyclohexen-3-ol
Trichlorocyclohexadientriol
Trichlorothiophenol
2,3,5-Trichlorophenol
2,3,6-Trichlorophenol
2, 4 ,5-T richlorophenol
2, 4, 6-T richlo~ophenol
3,4,5-Trichlorophenol
•
TABLEA-2
USEPA ANALYTICAL METHOD AVAILABILITY AND QUANTITATION
I LIMITS FOR BHC ISOMER DAUGHTER PRODUCTS
hlorobenzene I
ichlorocyclohcxadien riol
,4-Dichlorophenol
,4-Dichlorothiophenol
exachlorobenzene
ydroxydichlorothiophenol
m-Dichlorobenzene
o-Dichlorobenzene
p-Dichlorobcnzene
Pentachloro-2-cyclohexen-l-ol
Pentachlorobenzene I
Pcntachlorocyclohexene I Pentachlorocyclohexenol
Pentachlorophenol ]
1.2,3,4-Tetrachlorobenzene
I 1,2,3,5-T etrachlorobenzene
I 1,2,4,5-T etrachlorobenzene
T etrachlorophenol I
,3,4,5-T etrachlorophenol
I 2 ,3 ,5 ,6-T etrach lorophenol
T etrachlorocyclohexene [
etrachlorocyclohexenol
I 2,3 ,4,6-T etrachloro-2-cyclohexen-l-ol
I ,4,5,6-T etrachloro-2-c~lohexen-l-ol
1.2,3-Trichlorobenzene j
1,2,4-Trichlorobenzene
1,3,5-Trichlorobenzenc
,4,5-Trichlorobenzene
(36/45)-4,5,6-trichloroc clohexen-3-ol
Trichlorocyclohexadient I. ol
richlorothiophenol
,3,5-Trichlorophcnol
,3,6· Trichlorophenol
,4,5• Trichlorophcnol
,4,6• Trichlorophcnol
,4,5• Trichlorophenol
Notes: I
-= USEPA analytical method not available.
X = USEPA analytical mdthod available.
108-90-7
120-83-2
1122-41-4
118-74-1
541-73-1
95-50-1
I06-46-7
608-93-5
319-94-8
87-86-5
634-66-2
634-90-2
95-94-3
25167-83-3
4901-51-3
58-90-2
1782-00-9
78137-68-5
78137-69-6
87-61-6
120-82-1
I08-70-3
27941-98-6
993-78-8
933-75-5
95-95-4
88-06-2
57730-96-8
X
X
X
X
X
X
X
X
X
X
X
' EMMI = Environmental Monitoring Methods Index Database. USEPA (1995a).
TCL CRQL = Target Coriipound List Contract Required Quantitation Limit. USEPA (1994b).
I
5
IO
20
0.3 (a)
10
25
IO
(a) Value based upon USEPA Test Methods for Evaluating Solid Wastes (SW.846) recommended methodology
for converting a select~ Method Detection Limit (MDL) to a Practical Quantitation Limit (PQL) by
multiplying by a factor1 of 10 (USEPA 1994a).
TCLCRQL
TCLCRQL
TCLCRQL
TCLCRQL
TCLCRQL
TCLCRQL
TCLCRQL
EMMI
TCLCRQL
TCLCRQL
TCLCRQL
•
TABLEA-3
ORAL TOXICITY VALUES OF BHC ISOMERS AND DEGRADATION PRODUCTS
I
6.3E+O0 IRIS 177 Sax 1994
I.8E+O0 IRIS 6,000 Sax 1994
1,000 Sax 1994 gamma-BHC 0.0003 IRIS L3E+OO HEAST 76 Sax 1994
Degradation Products
ChJorobenzcne 0.02 IRIS NA NA Dichlorocyclohcxadicntriol
2,4-Dichlorophenol 0.003 IRIS NA NA
2,4-Dichiorothiophcnol
HcxachJorobcnzcnc 0.0008 IRIS I.6E+00 IRIS NA NA
Hydroxydichlorothiophenol
m-Dichlorobcnzcne 0.089 EPA Region 3
o-Dichlorobenzcnc 0.09 IRIS NA NA
~Dichlorobenzcnc 0.024 HEAST NA NA
Pcntachloro-2-cyclohcxen-1 o
Pcnt.achlorobcnzcnc 0.0008 IRIS NA NA
Pcntachlorocyclohcxcnc 2,930 RTECS
Pcntachlorocyclohcxcnol
Pcntachlorophcnol 0.03 IRIS 0.12 IRIS NA NA I ,2,3 ,4-T ctrachlorobenzcnc 1,167 Sax 1994
1,2,3,5-Tctrachlorobenzcnc 1,727 Sax 1994 1,2, 4,5-T ctrachlorobenzcnc 0.0003 IRIS NA NA
Tctrachlorophcnol 140 Sax 1994 2,3 ,4,5-T ctrachlorophcnol 400 (b) Sax 1994
2,3,5,6-T ctnchlorophcnol 0.03 IRIS NA NA TctrachJorocyclohcxcnc
Tctrachlorocyclohcxcnol
2,3,4,6-TctrachJoro-2-cyclohf
2,4,5,6-Tctrachloro-2-cycloh
1,2,3-Trichlorobcnzenc 1390 (•) Sax 1994
1,2,4-TrichJorobenzenc 0.01 IRIS NA NA 1,3,5-TrichJorobenzenc 800 Sax 1994 2,4, 5-TrichJorobenzcnc
(36/45 )-4,5,6-trichJorocyclohc
TrichJorocyclohc,cadientriol
TrichJorot.h.iophCl1ol
2,3,5-TrichJorophcnol
2,3,6-Trichlorophcnol 308 Sax 1994
2,4,5-T richlorophenol 0.1 IRIS NA NA
2,4,6-TrichJorophenol l.lE-02 IRIS NA NA
3,4,5-Trichlorophcnol
NOTES, I
- • No information available.
NA "' Not apphcable. Chronic toxicity value available.
HEAST"' Health Effects surnrnky Table. USEPA (1995b).
IRlS"' Integrated Risk Informatibn System. USEPA (1997)
RTECS::a Registry ofToxic Effects of Chemical Substances, 1997.
Sax 1994 = Dangerous Propenics' of Industrial Materials, 8th Edition
USEPA :a: U.S. Environmental Piotcction Agency.
EPA Region III= Ris\c-Ba.,erl ctincentration Table. USEPA (1996).
(a) A mouse intrapcritoncal LD50 J listed because no oral LD50 value is available.
(b) A mouse oral LD50 is listed bed.use no rat value is available.
•
ATTACHMENT A
LITERATURE REVIEWED
I
Adhya, T.K., Rao, V.R., Dani, R.C., Panda, D., and Sethunathan, N. 1995. Leaching of
hexachlorocyclohexarie isomers in a flooded field unplanted or planted to rice. Water Air Soil
Pollut. 81:305-313.
Agency for Toxic Substances and Disease Registry.
' Beta-, Gamma-, and Delta-Hexachlorocyclohexane.
Services. Atlanta, GAi:TP-93/09.
1994. Toxicological Profile for Alpha-,
U.S. Department of Health & Human
Alexander, M. 1994. Biodegradation and Bioremediation. San Diego: Academic Press, Inc.
Benezet, H.J., and Matsumura, F. 1973. Isomerization of y-BHC to a-BHC in the environment.
Nature 243 :480-481.
Bintein, S., and Devillers, J. 1996. Evaluating the environmental fate of lindane in France. ' Chemosphere 32:2427-2440.
Chadwick, R.W., cobeland, M.F., Wolff, G.L., Cooke, N., Whitehouse, D.D., and Mole, M.L.
1985. Effects of agel and obesity on the metabolism of Lindane by black a/a, yellow A vy/a, and
pseudoagouti Avy/a phenotypes of(YS x VY) F, hybrid mice. J. Toxicol. Environ. Health 16:771-
796.
Chadwick, R.W., Freal, J.J., Sovocool, G.W., Bryden, C.C., and Copeland, M.F. 1978. The
identification of thre~ previously unreported lindane metabolites from mammals. Chemosphere
8:633-640.
Cliath, M.M., and Spencer, W.F. 1972. Lindane and DDT. Environ. Sci. Technol. 6:910-913.
I
Drego, J., Murthy, N.B.K., and Raghu, K. 1990. [14C]-y-Hexachlorocyclohexane in a flooded soil
with green manuring. J. Agric. Food Chem. 38:266-268.
Engst, R., Macholz, R., Kujawa, M. Et al. 1979. Metabolism of lindane m microbial
organization, warm-blooded animals and humans. Gig. Sanit. 10:64-65.
Fitzloffi, J.F., and Pal, J.C. 1984. Epoxidation of the lindane metabolite, P-PCCH, by human-
and rat-liver microsori1es. Xenobiotica 14:599-604.
A-9
•
ATTACHMENT A
Fitzloffi, J.F., Portig, J., and Stein, K. 1982. Lindane metabolism by human and rat liver
microsomes. Xenobidtica 12: 197-202.
Francis, A.J., Spanggbrd, R.J., and Ouchi, G.I. 1975. Degradation of lindane by Escherichia
' coli. Appl. Microbiol. 29:567-568.
Haider, K. 1979. Dlgradation and metabolization of lindane and other hexachlorocyclohexane
isomers by anaerobic !nd aerobic soil microorganisms. Z. Naturforsh. 34:1066-1069.
Hamada, M., KawanJ E., Kawamura, S., and Shiro, M. 1981. Radiation and photo-induced
degradation of five isbmers of 1,2,3,4,5,6-Hexachlorocyclohexane. Agric. Biol. Chem. 45:659-
665.
Hiihnerfuss, H., Faller, J., Konig, W.A., and Ludwig, P. 1992. Gas chromatographic separation
of the enantiomers ofjmarine pollutants: 4. Fate of hexachlorocyclohexane isomers in the Baltic
and North Sea. Environ. Sci. Technol. 26:2127-2133.
I
Jagnow, G., Haider, K., and Ellwardt, P.C. 1977. Anaerobic dechlorination and degradation of
hexachlorocyclohexanb isomers by anaerobic and facultative anaerobic bacteria. Arch. Microbial.
115 :285-292.
Kennedy, D.W., Aust, S.D., and Bumpus, J.A. 1990. Comparative biodegradation of alkyl halide
insecticides by the white rot fungus, Phanerochaete chrysosporium (BKM-F-1767). Appl. I Environ. Microbial. 56:2347-2353.
I
Kohnen, R., Haider, K., and Jagnow, G. I 974. Investigations on the microbial degradation of
lindane in submerged I and aerated moist soil. Lectures held at the IUP AC Third International
Congress of Pesticide fhemistry, Helsinki, 3-9 July 1974.
McTeman, W.F., and Pereira, J.A. 1991. Biotransformation of lindane and 2,4-D in batch I enrichment cultures. Wat. Res. 25:1417-1423.
I
Registry of Toxic Effects of Chemical Substances (RTECS). 1997. National Institute for
Occupational Safety a~d Health (NIOSH). Washington, D.C.
. I
Sahu, S.K., Patnaik, K.K., Bhuyan, S., and Sethunathan, N. 1993. Degradation of soil-applied
isomers ofhexachlorotyclohexane by a Pseudomonas SP. Soil Biol. Biochem. 25:387-391.
A-10
•
ATTACHMENT A
Saleh, F.Y., Dickson, K.L., and Rodgers, Jr., J.H. 1982.
environment: Rate cohstants of physical and chemical processes.
297.
Fate of lindane in the aquatic
Environ. Toxicol. Chem. 1 :289-
Samuel, T., and Pillai, M.K.K. 1990. Effect of temperature and sunlight exposure on the fate of
soil-applied [14C]-gan\ma-Hexachlorocyclohexane. Arch. Environ. Contam. Toxicol. 19:214-220.
Sax's Dangerous Proberties of Industrial Materials, 8th Edition. 1994. Richard J. Lewis, Sr.
New York: Van Nostrand Reinhold Company.
Sharom, M.S., Miles, J.R.W., Harris, C.R., and McEwen. 1980. Persistence of 12 insecticides in
water. Water Res. 14: 1089-1093.
I Tsezos, M., and Wang, X. 1991. A study of lindane: Biosorption and biodegradation ' interactions. B.F.E. 8:120-125.
I
Tu, C.M. 1976. Util' zation and degradation oflindane by soil microorganisms. Arch. Microbiol.
108:259-263.
U.S. Department ofGommerce. 1980. Metabolism of Pesticides Update III. Washington, D.C.: ' National Technical Information Service. PB83-165498.
U.S. Environmental Protection Agency. 1993. Environmental Fa'te Constants for Organic
Chemicals Under Consideration for EPA's Hazardous Waste Identifications Projects. Atlanta,
GA: Office of research and development. EP A/600R-93/132.
I
U.S. Environmental ljrotection Agency. 1994a. EPA Test Methods for Evaluating Solid Waste
Physical Chemical Methods Integrated Manual. Volume I, Section B. Washington, DC: Office
of Solid Waste and Elnergency Response. SW-846.
U.S. Environmental Protection Agency. 1994b. USEPA Contract Laboratory Program:
Statement of Work for Organic Analysis. Washington, DC: Office of Solid Waste and Emergency
Response. PB95-96j503.
U.S. Environmental !Protection Agency. 1995a. Environmental Monitoring Methods Index ' (EMMI) Database. Washington, DC: Office of Solid Waste and Emergency Response.
I
U.S. Environmental Protection Agency. 1995b. Health Effects Assessment Summary Tables
' {HEAST). Annual F~-1995. March. Washington, D.C.: Office of Solid Waste and Emergency
Response. EPA 540/R-94/020.
A-11
•
ATTACHMENT A
U.S. Environmental Protection Agency. 1996. Risk-Based Concentration (RBC) Table. Office
ofRCRA, Technical 1nd Program Support Branch. USEP A Region III. Philadelphia, PA.
I .
U.S. Environmental Protection Agency. 1997. Integrated Risk Information System (IRIS). ' National Center for Environmental Assessment (NCEA). Cincinnati, OH.
I
Waliszewski, S.M. 1993. Residues of lindane, HCH isomers and HCB in the soil after lindane
application. Environ! Poll. 82:289-293.
Yule, W.N., Chiba, M., and Morley, H.V. 1967. Fate of insecticide residues. Decomposition of
lindane in soil. J. Ag~. Food Chem. 15:1000-1004.
I
Zoeteman, B.C.J., Harmsen, K., Linders, J.B., Morra, C.F.H., and Slooff, W. 1980. Persistent
organic pollutants in river water and groundwater of the Netherlands. Chemosphere 9:231-249.
A-12
t-
I GEIGY CHEMICAL CORPORATION SITE
DOWNGRADIENT AREA REMEDY DECISION TREE
I
L-iiiiited;Ai:liffri Al}l::f_!~)ti~c)\}orli1ori.~,g,.~ _ . , .,._
;surf2cc'\Vilicr •S1r"c1',il~'.Scdim~~lk ~•J)r_i~1hi~g" \Va1Cr_;
:j Au:1t•1rmcntll&I·
,. ·,n1ifo,1)c\,c1opmcn't ... ; IUE!~r!.!IDGII ::
Contii1gci1c)'_ Dc\·clopmcnt ,
.. ~•; . ldt'iitir"\· ,\r'eJs Of t~•;,,li:t·rn·/)
-C1111:;ci~::\pel'lcd:l)urati,,11 . Nn Yes
Identify Poteiltiul Corn'Cth:e~H------,
~l~·a\u_~s ~ ' , .,. · ., -., ~
;·· Gi;f,·1i nJ!c~~-,., 1~~1plc'i'.,e_1liil-iit"~,-i·
•· '. _·i,i1pll'll1t~,;i 1\11'.Ji.~i·,,:,.j~fil,_;~: ;'.
-ht1J•m·1t•d ,\rt•afst· .. .;--:•-, ~
-(;'onthiiit! Rcnlti1h: . -·~-:-r: ·:. • . . .
. . . .... " -~4-
-·•· -\ •• i', ,., ·, -, ,l ' -., !'. .
.Q1mfterly-Moriitoring_A·,1-r1:Rcport,ing . . '. ,. '. :, :' 'y .:•. J
I
,,h15 Ycar-i'criod iC: R~inCd ,, 'RCvic\,·s . . -. .. . --..
""" : ].)_~\ttJwl11ilt'n11.~I_··~-f -~ ·
No
:sc~{faimu,_li 1\1.,i-,ii,ri:i~g-~~ci R_fpo~;ting-, .
-..:. . , '.(\'cal"S·:Ho·S) (/J. .. ,
. .... "it)a1a"l>Cvcl;,pment ·:l .. ,~~,;1~1r~~~,:i"·---r-.. -
i Arinunl Pl,st-Att_nin1l_1ci11 l\··loi1ltli"ri_,lg
,, . ". · ' 'A ncl:Rc[)nrling_ 1.'~-· • Yes No ~ --·A,;m~;,1 Moniiori;;gAnd-R~IM>;ti_ng·', >-+.:::...-.,: ·:/ i:';(Up(H!r,And~(if·Lo~,:cr.lll~ck,.. · .. ,:., , · :(Up"pcl". A"nd/p"r)~ii~,·cr;m,ick
.r--•· G•·C~k_Aql1i(cr·s):
Yes
Con\in:;c ·Anllufll ~.,~-~1-;\ i1~~i,;•11~1~1
~~ . ~ ic_;,li1oring An_d ·Rc1>•·•~·fing•·· >.·
•(UpJ)cr And/Or:·Lm\·cr;lllnCk' _5'_
·' .···:: -~·-"CrCcKX<1i1ifCi:sr ~ _-, '
Remedy Task (Dd11ils Described In Rererenced Attachment. Where
Applicahle)
Mnnitorin~ And Reportin~ Fre11uency
(Grnundw:1tcr/Surface Water/Stream Sediment/Drinkin~ Water)
Meelin~s With A~encies (Evaluution Criteria Descrihed In
Rererenced Attachment)
Decision Point
Limited Action Altt>rnative Completion
·,:-:." . <;rcCk .A<1liifers) (o .. -j
Notes:
( I) -Monitoring Consists or (;roundwater And
Surface Water/Sediment Sampling Locations In
McFarland's Branch. !\fonitoring Followin~ The
Surface Water/Sediment Baseline S:1mpling
Event In Ray's !\·till Ami Aberdeen Creeks Will
He Based On Trigger Levels In Groundwater (See
Attachment I).
5/19197
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