United States
Environmental Protection
Agency . <
Of .ice of
Emergency and
Remedial Response
EPA/ROO/R03-87/035
June 1987
SEPA
Superfund
Record of Decision:
SALTVILLE WASTE DISPOSAL, VA
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--,
TECHNICAL REPORT DATA
(PfetIU MId l1uUtlctiont on th~ n"us~ bttfon CO",,,ltli,,,)
1. RI,.O..T NO. 13. 3. REC'I'IENT'S ACCESSION NO.
,
~1H ItH"lT"\/on1_R7'/01"
TITLe ANO SUBTITLE 5. AEPORT DATI
~UPERFUND RECORD OF DECISION .1,,",," 30. 1987
~altville Waste Disposal Ponds, VA 8. PERFORMING OR~ANIZATION COOl
IRM) .. -
--
7. AUTHORIS) 8. PERFORMING ORGANIZATION REPORT NO.
e. PERflORMING O..GANIZATION NAME ANO AOORESS 10. PROGRAM EI.EMENT NO.
11. CONTRACT/G}(AN T NO,
12. SPONSORING AGENCY NAME ANO AOORESS 13. TYPE OF AEPORT ANO PERIOD COVERED
~.S. Environmental Protection Agency IOq "",1 ROD ReDort
401 M Street, S.W. 1.. SPONSORING AGENCY CODE
Washington, D.C. 20460 800/00
15. SUPPLeMENTARY NOTes
18. ABSTRACT
The Saltville Waste Disposal site is located along the North Fork of the Holston
River (NFHR) between Saltville and Allison Gap in Western Smyth County, Virginia, and
partly extends into Washington County, .Virginia. The Jefferson National Forest is
located approximately one-half mile north of the site.
From 1895 to 1972, Olin Corporation and its predecessors (Mathieson Chemical
Corporation and Mathieson Alkali Works) used the site for various chemical manufacturing
operations. The site includes a former plant area and two waste ponds, 5 and 6.
Between 1951 and 1972, the Olin Corporation operated an electrolytic chlorine and
caustic soda plant which released mercury into the process wastes and onto the plant
grounds. Mercury losses were estimated by Olin Corporation to be 100 Ibs/day from the
chlor-alkali processes. In 1963, Waste Pond 6 was constructed to receive waste overflow
from Waste Pond 5. According to Olin corporation, no wastes containing mercury were
dumped into Waste Pond 6, but structural components of the old plant reportedly were
buried at the eastern edge of the pond. Since 1970, annual fish and sediment sampling
at NFHR has shown mercury" concentrations in" the sediments near the s~te and in fish
tissue at concentrations exceeding allowable limits. ' In 1983, the former plant area was
capped with clay and topsoil and seeded with grass, and a rip-rap of boulders and broken
stones was installed along the river edge. Mercury, the primary contaminant of concern,
{c:.,..,. A ~ . c"'...."'~ \
17. Key WORDS AND OOCUMeNT ANALYSIS
Ia. DESC"II'TORS b.IDeNTIFIERS/OPEN ENDeD TERMS c. CDSATI Field/Group
Record of Decision
Saltville Waste Disposal Ponds, VA (IRM)
Contaminated Media: air, soil, sediment,
surface water
Key contaminants: mercury
. DISTRIBUTION STATeMeNT 19. secuRITY C&.ASS tTllu Rtpo", 21. NO. OF PAGES
None 92
20. secuRITY CLASS IT/lit pal~1 23. PRice
1\1",,,,,,,
!,. ,- 2220-1 (R... .-77)
~"CVIOUI EOITION"'I0810I.CTC
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EPA!ROD/R03-87/035
Saltville Waste Disposal Ponds, VA
16.
ABSTRACT (continued)
has been detected at significant levels in soils, surface water, sediments,
air and river biota.
The selected interim remedial measure includes: upgrading runon controls
with ditches, berms, and/or downchutes; treating Waste Pond 5 outfall using
either sulfide precipitation techniques or carbon adsorption; installing
ground water monitoring systems; performing additional studies; O&M
treatment facility and continued up- and down-gradient NFHR sampling and
analyses. The estimated capital cost is either $840,052 or $2,143,052 with
annual O&M of either 221,941 or 258,941 pending selection of carbon
adsorption or sulfide precipitation treatment respectively. Capital and O&M
costs for the ground water monitoring system have not yet been developed.
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Record of Decision
Remedial Alternative Selection
Site:" Saltville Waste Disposal Site
Saltville, Virginia
. Documents Revi ewed
I am basing my decision concerning the appropriate interim remedial
alternative for the Saltville Waste Disposal Site primarily on the following
documents. A substantial number of additional documents are included in the
administrative record as well.
1.
Saltville Waste Disposal Site Risk Assessment (GCA, July, 1986 and
September, 1986).
2.
Saltville Waste Disposal Site Feasibility Study (GCA, August, 1986).
3.
Summary of Remedial Alternative Selection.
4.
Responsiveness Summary.
5.
The Comprehensive Environmental Response, Compensation, and Liability Act
of 1980, 42 U. S. C. ~ 960 1 ~~., as amended by the Superfund Amendments
and Reauthorization Act of 1986.
6.
The National Oil and Hazardous Substances Pollution Contingency Plan, 40
C.F.R. Part 300, November 20, 1985.
Description of Preferred Interim Remedial Alternative
Upgrade runon controls with ditches/berms/downchutes
- Treat Waste Pond 5 outfall using either sulfide precipitation techniques
or carbon adsorption
Additional Studies
Installation of ~roundwater monitoring system at conclusion of studies
Operation and Maintenance of treatment facility and continued sampling
"and analysis upgradient and down!'tradicnt of the tJFHR.
....... ." .
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Declaration
Consistent with the Comprehensive Environmental Response, Compensation,
and Liability Act of 1980 (CERCLA), as amended by the Superfund Amendments
and Reauthorization Act of 1986 (SARA or the 1986 Act), 3nd the Nation~l Oil
an~ Hazardous Substances Pollution Contingency Plan (NCP), 40 C.F.R. Part 300,
I have dete~ined that at the Saltville Waste Disposal Site, the selected
interim remedial alternative is cost-effectiYe and provides adequate
protection of public health and welfare and the environment.
The State of Virginia has been consulted and concurs with the selected
interim remedial alternative.
The action will require operation
continued effectiveness of the interim
insure that the performance objectives
groundwater quality criteria.
and maintenance activities to ensure
remedial alternative as well as to
meet applicable state surface 3nd
6/; ,if 7
l1ate
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. .
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May 19, 1987-
Mr. Thomas Voltaggio, Chief
Superfund Branch
United States Environmental
Region III
841 Chestnut Building
Philadelphia, Pennsylvania
Dear Mr. Voltaggio:
Protection Agency
19107
The Department of Waste Management (DWM) has reviewed the
draft Record of Decision for the Olin Corporation site in
Saltville, Virginia. As you are aware, the Virginia Water
Control Board (YWCB), other state agencies, and the United States
Environmental Protection Agency worked together several years ago
to develop a remediation plan for this site. In accordance with
that plan, Olin Corporation took remedial measures and has
conducted substantial fish sampling. Fish sampling conducted by
Olin according to an approved YWCB methodology leads to a
conclusion that the remediation of the site was successful in
reducing levels of mercury entering the Holston River and
entering the food chain. . .
Nevertheless, the Department of Waste Management recognizes
that the Superfund Amendments and Reauthorization Act of 1986
compels a more extensive remediation such as that contemplated by
~he draft Record of Decision. For this reason, DWM concurs with
the remediation proposed in the draft Record of Decision. The
Department looks forward to working with you and your staff in
this endeavor.
Very truly yours,
~ \
/ l . '.
/ .-z/Q/~l.
I / /A../ l / . I
If..,.'
C~thia V fBailey !
. .
.cc:
Richard N. Burton
K.C. Das, Ph.D.
Pauline M. Ewald
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Site Description and Summary of
Remedial Alternative Selection for
the Saltville Waste Disposal Site
Introduction
The Record of Decision (ROD) summarizes the Public Health and
Environmental Risk Assessment (RA) and Feasibility Study (FS) fo~r: the
Saltville Site. These reports were based on existing data and available
info~ation supplied by the Saltville Task Force and Olin Corporation
(responsi~le party for the Saltville Site). EPA did not perform a Remedial
Investigation (RI) at this site; because of the available data and
continuing sampling effort being conducted"under a Consent Order (discussed
under No Action Altetnative) between Olin and the Virginia State Water
Control Board (Va. SWCB). A decision was made to conduct a RA based on all
available data to determine if data gaps existed. Several data gaps were
identified in the RA. The FS developed alternatives based on the available
data, however, more data is needed to develop a final clea~up. An interim
alternative with additonal studies was selected to remediate the immediate
threat.
Site Location and Description
The Saltville Waste Disposal Site is located, as shown in Figure 1 along
the North Fork of the Holston River (NFHR), between the town of Saltville
and the community of Allison Gap in western Smyth County, Virginia, and
e~tends partly into Washington County, 'Virginia.
During the period from 1951 to 1972, Olin Corporation operated an
electrolytic chlorine and caustic soda plant at the Saltville Site. One
of the electrodes used in the chlorine-caustic process contained mercury
which was released into the process wastes and onto the plant grounds.
Waste Pond 5 was used to dispose of waste sludges from ~he chlor-alkali
processes. In 1963, Waste Pond 6 was constructed to receive overflow
from Waste Pond 5. No wastes containing mercury were dumped into Waste
Pond 6 according to Olin, but structural components of the old chlor-alkali
, plant reportedly were buried at the eastern edge of the pond. The site,-
as shown in Figure 2, includes, the former chlor-alkali plant area and
the two waste ponds. The NFHR lie9 in the area adjac'nt to the southern
border of the site and flows southwest to Tennessee. Figure 3 is a
schematic of the, Holston-Cherokee system! Sampling and analysis
conducted by the Task Force has demonstrated that hazardous substances
from the site have migrated to the NFHR, beginning from the area adjacent
to the Saltville Site, and continuing down-stream to Weber City. Virginia.
The former chlor-alkali plant area is currently capped with two feet
of clay followed by six inches of topsoil, and seeded with grass. Rip-rap
consisting of small boulders and hroken stones has been instaLlp.d along the
river edge. The site is heavily vegetated, with lush grassy Tegetation.
The si~e is fenced on three sides. bu~ is somewhat accessible by crossing
ehe river or by walking across ehe railroad bridge southwest of the siee.
The Jefferson National Forest is located approximacely 1/2 mile no~th
of the site. Topography of the area is rugged, lying within the Appalachian
Mountains. A small residential area of about 50 home9 is located between
the former chlor-alkali plant and Waste Pond 5. Immediately east of the
fo~mer chlor-alkali plant site is a factory (Hub and Wheels Company) which
employs approxima~ely 30 to 40 people.
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2
Site Hi story
During the period from 1895 to 1972, the Saltville Site was ~sed- by
Oli n Coporation and its predecessors (Mathieson Chemical Corporation and.
Mathieson Alkali Works) as the location for various c~emical manufacturing
operations. Mathieson Chemical Company built the mercury cell chlor-alkali
plant in 1950. The plant produced chlorine gas and sodium hydroxide by
. passing brine, obtained from salt deposits in the area, between electrodes.
The cathode used in .thi.s process contained meFcury and was the source of
mercury wastes. The current passing' through the brine caused the formation
of chlorine gas at the anode through electrolytic oxidation. At the same
time, a sodium amalgam was formed at the cathode. This amalgam was passed
into a decomposing tower where the sodium was separated by flushing it
with water to form sodium h:~roxide. Much of the mercury lost in this
process was solubulized and passed into .Pond 5 in the sludges and brine.
Additional mercury was lost through sloppy operating procedures. Mercury
losses were estimated by Olin at 100 lbs/day from 1951 - 1970.
In 1954, Olin Corporation merged with Mathieson Chemical Corporation.
In 1964, the Minimata Bay ~oisoning in Japan incident drew attention to
the toxic. effects of mercury in the environment. An investigation of
the plant site and nearby river revealed severe mercury contamination at
the site and in the river. As a result of fish and sediment sampling,
both Virginia and Tennessee placed a ban on fishing in the North Fork of
the Holston River. Later, both bans were reduced to cover consumption
of fish only.
After discovery of the problem, Olin modified its operating procedures
to cut mercury losses to 1/4 lb. per day. In 1970 the Va. SWCB adopted a
Total Dissolved Solids Standard of 500 mg/1 for the river, which Olin
was unable to meet. As a result of this, as well as increased operating
costs, Olin decided to close its Saltville operations. The final shut
down occurred in 1972. The chlor-alkali plant was demolished in 1973.
Since 1970, fish a.d sediment sampling in the North Fork of the Holston
River has been performed every year, showing mercury concentrations in the
sediments near the site and at concentrations exceeding allowable limits in
fish tissues. In 1978, a task force was formed by concerned agencies
including the Va. SWCB, Va. Attorney General's Office, Tenn. and Va. State
Departments of Health, the Tennessee V~lley Authority, and the USEPA. The
- task force has been involved in negotiations with Olin Corporation concerning
possible cleanup measures to solve or at least lessen the mercury contam-
ination problem in the NFHR. If' December 1982, the site was listed on the
Proposed National Priorities Li;t of 418 sites. In 1983 Olin diverted a
1300 foot section of the river Ind dredged 1000 feet of the exposed
river bed. Mercury was then extracted from the dredged. sediments. The
sediments were spread over the plant site, and encapsulated; then the
site was capped. In addition, Olin has placed rip-rap along the riverbanks
to stop erosion and has installed a western upland diversion ditch around
Pond 5 to lessen surf~ce water runoff flow into the pond. The diversion
ditch failed twice due to heavy rain, the most recent being in April
. 1987.
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U AiJi iPHING. VA QUAtlNANGLE I7.ft MINUTE SCRIES, 19)0. PHOTOHEVISEO I96». CONTOUR INTERNAL 2O'J.
Figure 2 Topographic map showing the area designated as the Saltville site.
Source: Orient, 1984.
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km 27T
Figure- 3 Schematic of Hols con-Cherokee system.
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3
Current Site Status
The contaminant of concern at the site is mercury. Sampling of air,
soils, surface water, sediments and biota from the NFHR has been performed
. during the past 15 years by Olin and the Task Force, with mercury being
det~cted in all media. Air monitoring has detected insignificant levels of
particulate mercury; however, elevated mercury vapor concentrations were
detected in June 1983" while remedial activities were being conducted at
the site. Surface water sampling by Oak Ridge National Laboratory (ORNL)
in 1975 detected insignificant levels«0.2 mg/l) of dissolved mercury in
filtered water, but significant ()lppm) levels of mercury on suspended
particulates in the river. Mercury in the Waste Pond 5 effluent ranged
from 10 to 120 I'g/~. Low levels of cadmium, lead and arsenic «1 ug/4 .
were also found in Waste Pond 5 effluent. The result of waste sampling
and analysis led to the conclusion that about 53,000 lbs of mercury are
contained in Waste Pond 5 with 92 percent (49,000 lb) contained in the
upper 17 1/2 ft. The mercury is concentrated in the west end, the north-
east corner, and the far east corner of the pond. Mercury in the upper 17
1/2 feet of these areas (29 acres total) represents about 69 percent 9f
the total mercury in the pond. Sediment sampling in the NFHR showed
that levels (above 1 ppm) are present at m08~ sampling stations up to 80
river miles downstream from the Saltville Site. The majority of fish
samples collected below the Saltville Site contained edible-portion
mercury concentrations greater than 1.0 ppm (FDA standard).
The known principal source of continuing mercury flux into the NFHR
is via seepage from the Waste Pond 5 outfall. Mercury flux into the
NFHR from ground water from waste ponds cannot be quantified due to the
absence of analytical data. It appears from reviewin~ all existing data
that not all of the potentially contaminated areas have been sampled.
The extent of the area acting as a possible source of contamination is
unknown and the quantity of mercury which can be leached to the groundwater
is unknown. Ii there is a vertical component of flow downward in the
. aquifer or if the horizontal flow component has not been fully determined
and some groundwater flows away from the river, then mercury leaching
into the groundwater may be impactin~ the aquifer and not just the river.
The geohydrology has not been fully characterized at the site, thus a
groundwater study for the area is needed before a final remedy can be
selected.
The major mechanism for removal of dissolved mercury from the water
column is absorption Jnto the surfaces of particulate phases and subsequent
settling to the river bed sediment. Additionally, s~me dissolved mercury
is ingested by aquatic biota or transported by river currents. Secondary
transformations of mercury in the sediments occur, these include prec.lp~-
tat ion as HgS and methlylation by bacteria. Since the mercury itself is'
not destroyed, the~e inorganic and organic forms of mercury may then
release ionic or metallic mercury into the water column as part of a
recycling process.
1\
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4
Resuspension of sediments by turbulance or activi ty of benthi c org.ani 5mS
can also release these compounds of mercury directly into the water
column. The primary sink for mercury released to the environment is thus
the sediCte~~s.
The alkylation of mercury to methyl~ and dimethyl-mercury is of
particular importance with respect t~ the envrronmental fate of mercury
for the following reasons:
Methylated mercury compounds are highly water soluble;
Tr.~j are rapidly and easily absorbed through biological membranes;
They are not readily degraded or released from the animal body; and
Mercury is preferentially soluble in the lipid-rich membranes of
living cells and, therefore, can be taken up from water by living
organisms.
Consequently, mercury accumulates in fish and other organisms, almost
enti rely in the form of' methylmercury and is. biologically magnified up
the food chain to higher fish and birds. These compounds are taken up by
fish directly through the gills, as well as through the food chain. It
has been reported that fish can concentrate methylmercury by an overall
factor of 3,000, while shellfish concentrate it by a factor of 100 to
100,000. This is particularly significant since alkylmercury compounds are
10 to 100 times more toxic than the inorganic forms.
The rivers of southwest Virginia support perhaps the richest density
and diversity of freshwater mollusks in the world. These river systems
present It support populations of ten species of freshwater mussels on the
Federal F.ndangered Species List. Recent field surveys indicate that the
NFHR above Saltville, Virginia supports a relatively diverse mussel fauna
of 15 species, one of which is an endangered species. Field surveys'
conducted below Saltville show the river to be devoid of mollusks for a
distance of 80 miles downstream to its confluence with the South Fork of
the Holston River. Historically, the North Fork below Saltville supported
.34 mussel species, four of which are now on the Federal Endangered Species
List (Va. Fish and Wildlife Service, January 6, 1987).
Concentratil,ns of mercury present in various fish species analyzed
below Saltville :or 75 miles show that mercury concentrations in fish
filets exceed 1 ppm for 85% of the fish. These mercury concentrations may
pose a chronic risk to various carnivorous mammals and fish eating birds
such as eagles and herons. As part of the 1983 Consent Order, Olin is
monitoring mercury concentrations in filets of juvenile northern hogsuc~e~s
and blue~ill to determine human exposure and environmental risks. Tissue'
conc~ntrations of mercury in filets do not reflect the total body burden
. of mercury and fish health. Many fish species contain the highest mercury
-concentrations in liver and kidney. Analysis of fish on a whole~body
.' basis or analysis of sped fie organs is necessary to determine the total
mercury present in the food chain and po.tentially available to predators
(Fish and Wildlife Service, January 6, 1987).
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5
Although extensive data has been collected on contaminants at the site,
this information is considered inadequate. Some of the problems -are:. the quali ty
assurance/ quali ty control data for all analysis is not available-; only filets --
from juvenile fish of two species are being analyzed; there are only five sampling
st~tions in over 80 miles of river; sampling stations were selected arbitrarily;
and much of the data is simply outdated. The Fish and Wildlife Service and BPA
believe that a complete bi~assessment of the biological environments potentially
impacted by contaminants at the site is necessary to adequately develop a
comprehensive set of remedial actions to mitigate or eliminate the impacts of
contaminants at the Saltville Site.
The concentrations of methylmercury in fish are believed to be highly
deo~.~ent on concentrations of mercury in river sediment. High concentrations
of mercury sediment occur in the 83 mile reach extending from the old chlor-
alkali plant to the confluence with the South Ford of the Holston. Highest
concentrations occur near the Saltvill Waste Pond 5 outfall (River Mile 82).
Any permanent action to solve problems from this site will have to address the
sediment as well as stopping the discharge of mercury from the site into the
river. A bioassessment of the NFHR will be initiated this summer.
Alternatives Evalutation
This section will .briefly define -the scoping of response actions for the
site, screening methods to determine appropriate remedial technologies, and
specific alternatives considered. The FS contains a more indepth analysis of
these discussions. .
A. Scoping of Response Actions for the Site. Pursuant to 40 CFR 300.689(e)
of the NCP, an initial analysis must be made during the RI/FS, prior to develop-
ment of alternatives, which will provide a preliminary determination of the
extent Co which Federal environmental and public health requirements are appli-
cable or relevant and appropriate to the specific site. A preliminary determi-
nation must also be made of the extent to which ocher Federal criteria, advisories,
and guidance and state standards are to be us~d in developing the remedy. The
following discussions provide such an initial anaylsis.
In performing chis institutional analysis several Federal and State statutes
and associated Federal and State regulatory programs were determined to be neither
applicable nor relevant and appropriate to the Saltville Sit~. As such, these
. statutes and/or regulatory programs were eliminated from further consideration 1n
this report. A list of these general statutes appears in Table 1. Table 2 and
the fol1:)wing text lists and discusses those ARARs associates with the Saltville
Site.
RCRA Subtitle C
RCRA Subtitle C and associated regulation (40 CFR 260 through 264) are
considered appli cable or relevant and appropriate to the Saltville site. 0° Mercury.
contaminated wastes at the Saltville site .are listed as U1SI RCRA wastes. Specific.
RCRA regulations applicable to the site include:
o
40 CFR 264 Subpart G - Closure and Post-Closure, specifically 264.111, .114,
.117, .119, .120.
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TABLE 1. STATUTES NOT APPLICABLE OR RELEVANT AND APPROPRIATE TO THE
SALTVILLE WASTE DISPOSAL SITE
Statutes Not Applicable or
Relevant and Appropriate
Justification for Elimination
Open Dump Criteria*
RCBA Subtitle D.
Coastal Zone Management Act.
Wild and Scenic Rivers Act.
National Historic Preservation
Act of 1966i Executive Order
11593.
None of the proposed remedial
alternatives call for open dumping.
The waste onslte is considered a RCRA
Subtitle C hazardous waste.
The Saltville site is not within or
adjacent to the Virginia coastal core,
nor are the proposed remedial actions
expected to influence the coastal zone.
The Virginia Division of Parks and
Recreation has verified that the North
Fork of the Holston River is not
currently a Federal or State
designated or proposed wild or scenic
river (CCA Telecon with Dick Gibbins,
June 1986).
There are no known historic properties
which could be adversely affected by
the proposed remedial alternatives.
The Saltville site Is not listed on
the National Register.
Atomic Energy Act, Low level.
Radioactive Vaste Policy Act.
Safe Drinking Water Act|
Underground Injection Control
Permit! Sole Source Aquifer
Permit.
-Toxic Substance Control Act;
Federal Insecticide, Fungicide
or- Rhodenticide Act.
There are no known radioactive wastes
contained at the Saltville site.
The Saltville site is not located on
or near a sole source aquifer or a
drinking water source. Proposed
remedial alternatives do not include
injection of wastes or treated water
into the ground.
There are no known PCB-eontaminated
wastes or pesticide-contaminated
wastes contained at the Saltville site.
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TABLE 2 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARa)
ASSOCIATED WITH THE SALTVILLE WASTE DISPOSAL SITE
Applicable or Relevant and
Appropriate Requirements
(ARARS)
Summary
RCRA Subtitle C
RCRA Regulations!
o 40 CFR 264 Subpart G
o 40 CFR 264 Subpart F
o 40 CFR 264 Subparta, K and N
o 40 CFR 263
Mercury 'contaminated wastes located
onsite (Waste Pond 5 and associated
effluent) are considered RCRA listed
hazardous wastes, EPA ID No. 0151.
Therefore, RCRA Subtitle C and
associated regulations are applicable
or relevant and appropriate to the
Saltville site.
Requires proper closure and post-
closure at RCRA sites.
Requires monitoring of ground water at
RCRA sites and implementation of
corrective action measures when ground
water contamination is evident.
Subpart G triggers these requirements
upon closure. Subpart F specifies a
maximum contaminant level for total
mercury at .002 mg/1 to protect ground
water (264.94).
Contain specific requirements for
run-on and run-off controls and capping
of surface impoundments and landfills.
If waste is left in place in Waste
Pond 5 upon closure, landfill
requirements (Subpart N) become
applicable. If wastes are removed upon
closure, surface impoundment
requirements (Subpart K) become
applicable.
Contains specific requirements for
transporting wastes offsite.
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TABLE 2
Applicable or Relevant and'
Appropriate Requirements
(ARARS)
Summa ry
Virginia Hazardous Waste
~~nagement Regulations
Virginia has received RCRA Final'
authorization. Virginia regulations
are similar to federal RCRA regulations
with some exceptions. The maximum
contaminant level to protect ground
water is .002 mg/l for total mercury
Section 10.06.05).
Clean Water Act
The federal CWA and associated
regulations are applicable to the
Saltville site because the site is
directly impacting the quality of the
NFHR (a navigable water way) and its
fish and biota.
o
CWA Section 304
EPA has published federal ambient water
quality criteria for the protection of
freshwater aquatic life. Federal
criteria for total recoverable mercury
in freshwater is 0.012 ppb. Federal.
criteria are not legally enforceable.
o
CWA Sections 401 and 404
Under Section 404, the Army Corps of
Engineers has permit jurisdiction
over projects located in or directly
impacting waters of the U.S. by way of
the discharge of fill material. EPA
has the responsibility of evaluating
proposed actions, to ensure a minimi-
zation of aquatic impacts, in accordance
with the Section 404 (b)(I) guidelines,
40 CFR Part 230. Any proposed remedial
alternative involving the discharge of
fill material located in or directly
impacting a water of the.U.S. must be.
regulated by the Corps. Under Section
401, the governing agency (Federal' or
State) must certify that the project
(alternative) ~eets all " applicable
regulations and guidance. The NFHR is
the only water of the U.S. in the
vicinity of the Saltville site.
o
Section 10 of the River and
Harbor Act of 1~99.
The River and Harbor Act requires
authorization from the Corps of
Engineers for any excavation in
the navigable waters that would
be responsible for altering its
conditions or capacity.
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TABLE 2
Applicable or Relevant and
Appropriate Requirements
(ARARS)
Summary
o
CWA Section 402, 40 CFR 122
Effluent flowing from Waste Pond
5 to the NFHR is currently not
permitted, however, it may be sub-
ject to a NPDES permit in the future.
Alternatives proposing to treat th~
effluent prior to entering the NFHR wil
be dictated by the NPDES permit procees
Virginia State Water Control Law
The State Law and associated regulation
are applicable to the Saltville site
because the site is impacting the NJ.o'HR
and its fish and biota. Virginia has
authority to administer its own NPDES.
program and has promulgated state water
quality standards.
Virginia Water Regulations:
o
Virginia Water Quality Control
Standards (Effective 5/28/86)
Total recoverable mercury standard in
fresh water is 0.05 ppb methyl mercury
Although it is stated within the standa
that they are not applicable to the NFH
until January 28, 1987, the Task Force
has informed Olin that Olin should con-
sider these standards applicable to the:
The methyl mercury standard is not
currently being used at the Olin site d.
. to the lack of methyl mercury data.
Therefore, the total recoverable mercur
water quality standard of O.OSppb is th
only legally enforceable ARAR for NFHR.
o
Virginia Water Quality Control
Policy (Effective 5/28/86)
Total recoverable mercury in edible
fish tissue shall not exceed 750 ppb;
total mercury in fresh water river
sediments shall not exceed 300 ppb.
These policy levels act as action
II
. ,
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TABLE 2
Applicable or Relevant and
Appropriate Requirements
(ARAR~)
Summa iy
levels which trigger some type of
agency attention/action when
exceeded. These action levels
have been exceeded and a fishing
ban on the NFHR currently exi~ts
in the vicinity of the Olin facility
and downstream.
Floodplains and Wetlands Guidance,
Executive Orders 11988 and 11990
These guidance and Orders state the
procedures of floodplain mar.agement
and wetland protection. Executive
Order 11990 restricts federal
agencies from undertaking or
providing assistance for construct-
ion in wetlands. Executive Order.
11988 requires that Federal activi-
ties in floodplains must reduce
the risk of flood loss, minimize
the impact of floods on human
safety, health and welfare and
preserve the natural and oeneficial
values served by floodplains. A
FEMA flood prone map ind~cates
that only a portion of the river
bank is in the lOO-year iloodplain.
If a proposed remedial alternative
Is to be located within the lOO-year
floodplain, it must be consistent
with state and local floodplain
and zoning requirements.
Fish and Wildlife Coordination Act
Federal agencies issuing a permit to
modify any body of water must cor'sult
with Federal and State wildlife
agencies to ensure that resources
are appropriately protected. Any
proposed
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TABLE 2
Applicable or Relevant and
Appropriate Requirements
(ARARs)
Summary
OSHA, 29 CFR Parts 1910 and 1926
Archeological and Historic
Preservation Act of 1974
National Environmental Policy
Act (NEPA)
Government and Public Involvement
remedial alternative that may affect
the NFHR must be reviewed by the U.S.
Fish and Wildlife agency as well as the
Virginia Fish and Game Commission and
the State Water Control Board.
Any proposed remedial alternative which
requires workers to enter CERCLA sites
must provide for adequate protection of
human health. Regulations and guidance
promulgated under the Occupational
Safety and Health Act must be
considered prior to implementation of
any alternative.
The Archeological Research Center in
Richmondt Virginia has determined that
the Sa'ltville site has potential to
contain significant archeological
deposits. Prior to choosing a remedial
alternative) the Center must make a
final determination on archeological
significance in the area and be
included in reviewing the proposed
alternatives.
Federal agencies are required to
consider all environmental impacts of
proposed alternatives. NEPA requires
the preparation of an Environmental
Impact Statement (EIS) and compliance
to associated procedures. If the
proposed alternative complies with NCP
requirements at 40 CFR 300.68 and there
is sufficient opportunity for public
comment, an EIS is not required.
CERCLA requires public involvement
during the FS process. Guidance is
included in the EPA publication
entitled "Community Relations in
Superfund: A Handbook".
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6
RCRA Subtitle C
o
40 CFR 264 Subpart N - Landfills, specifically 264.jl0 and .301 (c), (d),
(e). This Subpart becomes applicable if the mercury contaminated wastes
remain in place in Muck Pond 5 at closure. RCRA contains provision for.
capping and ninon and runoff controls. EPA has published gU1:dance on RCRA--
landf ill caps.
o
40 CFR 264 Subpart K - Surf~ce Impoundments. This subpart becomes applicable
. if the mercury contaminated wastes in Pond 5 are removed prior to or during
closure.
o .
40 CFR 264 Subpart F - Groundwater Protection. This Subpart is triggered by
. Subpart G upon closure of the site. The EPA Regional Administrator will need
to specify hazardous constituents to moni~or for, the point of compliance, and
the groundwater concentration limit (MCL) of 0.002 mg/J ~ercury for ground-
.water protection. Under 264.100 corrective action is required if groundwater
concentration is discovered during monitorings specified under Subpart F,
which exceeds the required standrd.
The Hazardous and Solid Waste Amendments of November 1984 (HSWA), amending
RCRA, may also trigger corrective action to be implemented offsite for releases
that have migrated offsite.
The.State of Virginia has authority to run the RCRA program in Virginia.
The Virginia hazardous waste management program is implemented and enforced by
the Virginia State Department of Health (DOH), Division of Solid and Hazardous
Waste Management. The applicable statutes and regulations are Chapter 6, Title
32.1, Article 3, Code of Virginia (1950), Solid Waste Mana~ement and the Virginia
Hazardous Waste Management Regulations. The Virginia statutes and regulations
are substantially equivalent to their Federal counterparts with some more stringent
provisions. Under groundwater protection, the Virginia regulations specify a
maximum contaminant level (MCL) of 0.0002 mg/l of mercury (Section 10.06.05).
In addition, RCRA regulations contain provisions ~pplicable to hazardous waste
transportation, treatmen~, and disposal (40 CFR Parts 262 - 264). For example,
remedial alternatives proposing to transport waste offsLte will need to be perform-
ed in compliance to 40 CFR 263. In addition, alternatives to treat and/or remove
wastes will need to be in compliance with applicable subparts under 40 CFR 264.
Clean Water Act
The Federal Clean Water Act (CWA) , as amended, and similar State Water Control
Laws and regulations are also applicable to the Saltville Site. Section 304(a)(l)
of the CWA sets forth ambient water quality criteria for the pr.tection of freshwater
aquatic life and human health. The Federal criteria for total recoverable mercury
in fre~h water is 0.012 ppb.
The Virginia SWCB has the authority under the CWA to promulgate water quality
laws and standards. The Virginia State Water Control Laws and standards are legally
enforceable. Virginia promulgated the following state standards: 0.05. ppb of ,
total mercury in freshwater and 0.02 ppb of methyl mercury in freshwater, effective
May 28,l986. Virginia has also published a policy document for mercury in fresh'
water .which states that. effective May 28. 1986, the level of methyl mercury in
edible fish tissue shall not exceed 750 ppb and the level of total mercury in
freshwater river sediments shall not exceed 300 ppb.
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7
Exceedence of these levels will trigger an investi~dtion, possible abatement
actions and other actions such as imposition of a fishing ban.
Protection of fTeshwater aquati~ life i~ of importance to Saltville because
of the presence of freshwater fish and associated biota in the NFHR./ The river,
classified as a mountainous stream (Class IV), has been a frequented recreational
fishing area for many years. A State fishing ban has been in place of the
vicinity of the Olin plant and downstream to the Tennessee border since the
early 1970s. The fishing ban, put in place by the ~irginia DOH, was the result
of discovering that fish in the area of the Olin plant possessed mercury concen-
tration levels in the fish tissue exceeding FDA's action level of 1 ppm total
mercury. The fishing ban has remained in place and is not expected to be lifted
in the near future. Additional State standards, under the Virginia Water Quality
Control regulations, that apply to Class IV waters include: minimum of 4.0 and
daily average of 5.0 mg/l of dissolved oxygen, maximum temperature of 31°C, and
a pH range between 6 and 9.
'Section 402 of the CWA covers the implementation of the National Pollutant
Discharge Elimination System (NPDES) permit program. Virginia is authorized by
EPA to administer the State NPDES program. Applicable regulations are the
Virgini~ Discharge Permit Regulations also promulgated uqder the Virginia Water
Control Laws. The Virginia NPDES program covers the discharge of sewage,
industrial wastes, and other pollutants to waters of the State of Virginia.
Section 404 of the CWA covers filling activities in waters of the U.S.
including wetlands areas. The Army Corps of Engineers has the authority to
regulate construction activities in waters of the U.S. Any activities proposed
in such waters will need to be permitted by the Corps, and reviewed by EPA and
the U.S. Fish and Wildlife Service. Activities ~roposed in the river such as
dredging will require authorization pursuant to Section 10 of the Rivers and
Harbors Act of 1899, as well as the Virginia Marine Resources Commission who has
jurisdiction over the subaqueous beds and lands, and the Va. SWCB who has juris-
diction over freshwater water quality. The Virginia Commission of Inland
Fisheries and Game, and most likely the Va. DOH, will also require a review of
- the proposed activi ties.
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8
There is only a smail--portion of.the banks of the NFHR are in a 100-year
flooaplai n. Waste ponds 5 and 6 and surrounding borders are not locat ed in
a 100year floodplain. Proposed alternatives involving construction of a
treatment facility on.the bank of the River will not likely trigger the
floodplain regulations and guidance.
National Environmental Policy Act
The National Environmental Policy Act (NEPA) requires that Federal agencies
consider all environmental impacts of proposed actions. NEPA, therefore, .
contains applicable statutory requirements for Saltville. Procedures for
implementing the Act are specified at 40 CFR 6, and include preparation of
an Environmental Impact Statement (EIg). However, according to EPA's recent
feasibility study guidance, remedial actions under CERCLA are exempt from
the EIg requirement 1f two conditions are met: 1) the remedy complies with
NCP requirements at 40 CFR 300.68; and 2) there is sufficient opportunity.
for public comment. Both of these conditions are expected to be met, therefore
there is no requirement for an EIg for activities taken pursuant to CERCLA
at the Saltville site.
Government and Public Involvement
Public involvement is required by CERCLA during the FS process and is
therefore applicable to the Saltville site. Guidance for achieving this
objective may be found in the EPA publication "Community Relations in Superfund:
A Handbook." Information on communi ty relation plans (CRPs) and public comment
periods on the FS and selection of the rer.edial alternative are outlined in
this guidance document. Use of a CRP (specified at 40 CFR 300.67) and .the
involvement by EPA and the State of Virginia in the RI/FS review process
(NCP. 40 CFR 300 Subpart B) will facilitate meeting the requirements of
Executive Order 12372 and 40 CFR 25.
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c
oJ
OSHA
Worker safety and health at CERCLA sites is an important element in all
response actions. Pursuant to CERCLA 111(c) ~6), EPA, the Occupational Safety
and Health Administration (OSHA) and the National Institute for Occupational
Safety and Health (NIOSH) are jointly developing a program to ensure employee
protection at Superfund sites. 40 CFR 300.38 of the NCP requires that the
OSHA requirement be applied to all CERCLA response activities. Existing EPA
~uidelines for worker safety inclu~~;
o Osha Interim Final Standard to protect workers in hazardous waste
operations, 29 CFR Part 1910, December 19, 1986.
o EPA Occupational Health and Safety Manuals.
Existing OSHA standards codified in 29 CFR Part 1910 - General Industry
Standards and 29 CFR Part 1926 - Safety and Health Regulations for construction
are directly applicable to working conditions.at Superfund response sites. The
NCP requires Superfund remedial actions to comply with all applicable OSHA and
EPA requirements. .
Archeological and Historic Preservation Act of 1974
Although there are no known prehistoric, historic, or archeological data
or materials contained at the Saltville site, Mr. Larsen of the Archeological
Research Center in Yorktown, Virginia believes that the North Fork Area is of
great potential for archeological significance. The river beds may pose
minimal potential for resources but the river banks and surrounding area hold
evidence of prehistoric activi ties as well as civil war artifacts, and 19th
and 20th century pottery. Mr. Larsen suggested that specific site location
information be sent to his a~ency for review before any activity begins.
In a4dition, Indian activity is believed to be present in the North Fork region
and will need to be investigated, and impacts from remedial alternatives will
np-ed to be assessed prior to implementing remedial activities. If this
Archeological Re~earch Center determines that significant archeological deposits
exist on the Saltville site, the Archeol)gical and Historic Preservation Act will
become appli cable to the Saltvi 11e si te and wi 11 need to be considered prior to
choosing and implementing any remedial alternatives.
. .
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10
Floodplains and Wetlands Executive Orders and Guidance
EPA guidance and Federal standards on floodplains and wetlands ar~
applicable for certain proposed remedial alternatives. Applicability depends
upon the exact location ot the. remedial activity because only limited
areas at the Saltville site are in a lOa-year floodplain or a wetland area.
EPA Draft Policy on Floodplains and Wetlands Assessments for '.CERCLA.
Actions states that CERCLA actions must meet, to the extent practicable,
the substantive requirements of Executive Order 11988 - Floodplains
Management, Executive Order 11990-.- Protection of Wetlands, Appendix A .
to 40 CFR Part 6 Statement of Procedures on Floodplains Management and
Wet lands Protection as .well as in the National Flood Insurance Program
(NFIP). EPA's policy states that for removal actions the onscene coordinator
(OSC) should consider, whenever possible, the effect the response action
will have on floodplains and -wetlands. For remedial actions, a floodplai n/
wetlands assessment must be incorporated into the analysis conducted
during the planning of the r~~cdial action(s). Appendix A to 40 CFR
Part 6 states that if there is no other feasible alternative, construction
must be consistent with standards under the NFIP at 44 CFR Part 60 -
Criteria for Land Management and Use. The standards under the NFIP
primarily address construction of and improvement to residential communities
with relation to flood insurance in flood prone areas and are therefore
not directly applicable to this site. The standards include, under
certain circumstances, prohibiting development which may increase the
water surface elevation of the base flood and requi ri ng floodproofi ng
cert Hied by a re~istered engi neer. These standards could become relevant
and appropriate if proposed remedial alternatives includes construction
in a floodplai n.
Executive Order 11988 requires that any Federal action in a floodplain
reduce the risk of flood loss, minimize the impact of floods on human
safety, health and welfare, and restore and preserve the natural and
beneficial values served by floodplains. Federal agencies must evaluate
alternatives to avoid adverse effects and incompatible development in the
floodplains, and to mimimize the potential harm to flooodplains if the
only practicable alternat~ve requires siting an action in a floodplain.
Early and adequate opportunities for public review of plans and proposals
involving actions in floodplains must be provided. A floodplain/wetlands
assessment must co~sist of a description of the alternatives considered
and their effects on the floodplains and wetlands, and measures to minimize
potential harm to the floodplains and wetlands.
The Federal Emergency ~lanagement Agency (FEMA) in Region III was
contacted by EPA. Mr. Tom Majusiak of FE}1A stated that the town of
Saltville had specific re~ulations, criteria and standards for activities
in a lOa-year floodplain. He requ..sted that a detailed letter be sent
to him outlining any proposed activities in a lOa-year floodplain and
stated that the town must review ":ne proposed activities and approve
them.
. .
II
I
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11
Fish and Wildlife Coordination Act. Conservation Act and Advisories
The Fish and Wildlife Coordination Act. et ale requires Federal agencies.-
issuing a permit to modify any body of water to, consult with State and Federal
wildlife ~gencies to ensure that resources are appropriately protected.
Coordination would be necessary at the Saltville site with a number of State
and Federal agencies including -the Va. SWCB. the Virginia Marine Resource
Commission. Virginia ~omm1ssion of Game and. Inland Fisheries. and potentially
the Corps of Engineers. Coordination would be necessary for those alternatives
which may impact the NFHR.
It should be noted that the Saltville site is bordered, in part, on the
north by the Clinch ~ountain State Wildlife Management Area (CMSWMA). The
Virginia Commission of Game and Inland' Fisheries has jurisdiction over this
State natural resource. Dr. Jack Randolf of the Commission requested that a
letter detailing any proposed alternatives that may impact the CMSWHA be sent
to him for review.
B.
Screening of Re~edial Technologies
In this section of the Saltville ROD, general response actions are identified
and remedial technologies are screened, in'order to identify the most technically.
feasible remedial technolo~ies that could be used to formulate remedial alternatives
for the site. Table 3.1 provides a summary of both those source control and managemer,
of migration general response actions and associated remedial technologies identified
for the site.
Factors used in Screening Remedial Technologies
Technical Criteria
applicability to site conditions
applicability to waste characteristics
effectiv. ness and reliability
implementabUity
Environmental and Public Health Criteria
Cost Criteria
increased cost offering no greater reliability
or effectiveness.
increased cost Q:fering no great protection of public
health or environment as established by criteria.
Institutional Criteria (ARARs)
. .- .
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TABLE 3.1.
SUMMARY OF GENERAL RESPONSE ACTIONS AND ASSOCIATED REMEDIAL
TECHNOLOGIES IDENTIFIED FOR THE SALTVILLE WASTE DISPOSAL SITE
Remedial Technologies
A.
Source General Response Actions
---
1.
No Action
2. Containment
3. Dhers1Ot1
4. Removal (Complete/Partial)
5. Treatment
(a) Waste Pond Material
1. In situ
2. Ond te/Of f s1 te
(b) Pipe discharge
6. Disposal (Onsite/Offsite)
B. Management of Migration
General Response Actions
.1. No Action
2. Containment
3. Diversion
4. Removal (Complete/Partial)
5. Treatment
6. Disposal (Onsite/Offsite)
Continue existing sampling program
beyond 4/26/88; maintain existing
runon controls & cap.
Capping/Cover,
Surface Water Runon Controls
Excavation
Chemical Stabilization and enhanced
leaching
Phy'~cal/Chemical/Biological
Wastewater Treatment
Land disposal
Continue existing sampling
program/ban within NPHR
Capping. grouting/seala and dikes
(dam,)
Floodwalls/levees, berms/dikes, etc.
Mechanical, hydraulic and pneumatic
dredgtng
Chemical Stabilization
Land disposal
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12
The followin~ provides a description of remedial actions that will be
screened.
Capping
Capping of waste materials is a proven technology for minimizing surface
water infiltration. Capping is viable for Waste Pond 5 due to its potential
ability to prevent large amounts of surface water (i.e. precipitation and
surface water run-on) from infiltrating through the sludge and migrating
into the NFHR. It has been estimated by GCA, the contractor for the RA/FS
(see Appendix 2). that if infiltration through the sludge is prevented
(i.e.. throu~h use of a capping technique), flow from the outfall of Waste
Pond 5 could be reduced by approximately 80 percent on average (from 0.05
cis currently, to 0.01 cfs). As such, various capping technologies have
been considered for this site, and are listed, described and screened.
Table 3.2 lists the types of caps that are potentially applicable to Waste
Pond 5 at Saltville.
TABLE 3.2.
CAPPING TECHNOLOGIES EVALUATED FOR THE SALTVILLE
. WASTE DISPOSAL SITE
Compact ed 5011
Clay soil compacted to low permeabilities
Flexible Membrane
HOPE
, PVC
HyPalon
Lj ner
~tult ilaye r Cap
RCRA Cap
Admixed L'ners
Hyiraulic Asphalt/Concr~te
S'iil/Cement
Soil/AsphaLt
Sprayed-On Linings
. .
5011 Sealants
Man-made St ructures,
Dome
Roof Structllre
-------
.....>
Table 3.3 summarizes the screening of the cappin~ remedial technologies
evaluate~. Based on the evaluation of cappin~ technologies presented above, it
, it appears that the most feasible cap is a Flexible Membrane Liner (FML)
designed to endure the stresses that ~aybe induced by Waste Pond 5. This
capping technology is the most feasible because of its demonstrated performance
record and particularly due to its lightwei~ht nature, its ability to endure
stresses induced by differential settleme"t, the relative ease in constructing the
cap and the relative short amount of time needed to meet the re~ed~al object~ye.-
Although under normal conditions other designs may offer more protection.
for Waste Pond 5, FMls appear to be the only capping technology that could
r~main effective with relatively minimal maintenance in th~ longer term.
It should be ,noted that the use of a multilayered cap could be potentially
applicable to the site. However, 'due to the extent of site preparation that is
needed to install the cap (i.e. preconsolidation) and the difficulty in
implementation, a lightweight flexible membrane liner is more feasible for this
site.
Compacted soi1 caps are relatively heavy and possess no tensile strength.
Therefore their usefulness as a low permeability cap for Waste Pond 5 is
11mi ted.
Admixed Liners, Sprayed-on Liners and Soil Sealants all are limited in
demonstrated performance. Furthermore, since they would adhere to the surface
of the sludge, cracking would likely occur under the slightest amount of sludge
settlement.
Large Man-made Structures would be difficult to construct at Waste Pond 5
due to the size of the site and topography and nature of soils around the
perimeter of the site.
TABLE 3.3.
SUMMARY OF CAPPING TECHNOLOGY SCREENING
Technology
Screening Factors
Feasible
Completed Soil Cap 1. Very heavy
2. Possesses no tensile stren~th No
and therefore will 'fail if
settlement occurs.
3. Would require preconsolidation
Flexihle Membrane 1. Proven to be effective in
Liner waste containment applications Yes
2. Lightweight
3. Possesses tensile strength and
elon~ation potential
4. Relatively easy to implement
5. Relatively short amount of time
needed to meet remedial objective
6. Can be expected to stay intact
for 50 years
7. Easy to repair
-------
Multilayered Cap
Admixed Lininll;
Materials
Sprayed~n Linings
Soil Sealants
Man-made Structures
Surface Water Runon Control
14
1 .
2.
3.
V"!ry heavy
Would require preconsolidation
Difficult to implement
No
1 .
2.
Limited experience
Brittle - very likely to crack
. No
1.
2.
3.
Limited experience
Difficult to iqstall flawlessly
cracking is likely
No
1
2.
Limited experience
Degraded by freeze-thaw,No
wet-dry cycles
Likely to crack
3.
t.
2.
Limited experience
Soil around perimeter of
site may not support a
structure.
No
Surface water runon controls are appropriate technologies to be considered
as a means of reducin~ mercury discharges from Waste Pond 5 that are caused
by the erosion of sludge due to surface water runon/runoff. In addition,
surface water runon control measures would aid in reducing the transport of
mercury contaminants to the groundwater, and eventually the NFHR, caused by
surface water infiltration of subsurface sludRe layers.
GCA has estimated, based on previously reported data, that approximately
70 million gallons of surface water could drain onto Pond 5 each year in
the absence of any surface water control/diversion systems. As such, a partial
surface water runon control system was installed in April 1983 (per the require-
ments of the "Special Order") to collect approximately 7 5 percent (104 acres of
the total 139 acres) of the drainage area located along the western edge of Waste
Pond 5.
Table 3.4 lists five surface water runon control technologies. These
technologies are described in detail and then screened in this subsection in
order to assess their feasibility to the Saltville site relative to diverting
the remainin~, uncontrolled amount of surface water drainage entering Waste
Pond 5.
. .
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15
TABLF. .3.4.
SUr$ACE WATER RUNON CONTROL TECHNOLOGIES EVALUATED
FOR THE SALTVILLE SITE
Remedial Technolo~ies
o
Dikes and Berms
Diversion Trenches and Ditches
Chute~ and Downpipes
Terraces and Benches
Seepa~e Basins and-Ditches
o
o
o
o
Upon completion of the preliminary screening process, it was determined
that three surface water run on control technologies are applicable technologies
to be considered for implementation at Waste Pond 5. The three applicable
technologies are listed in Table 3.5, along with the screening factors which
eliminated those two remaining surface water control technologies.
TABLE 3.5.
SUMMARY OF SURFACE WATER RUNON CONTROL TECHNOLOGIES SCREENING
Surface Water
Runon. Control
Technology
Feasible to
Waste Pond 5
as a RunOn
Control Technology
Significant Screening Factors
Dikes and Berms
No
Better suited as a temporary or
emergency measure. Draina~e area
restricted to a 5 acre maximum.
Diversion Trenches
and Ditches
a. upgrade current
system
b. new channel
- construction
Yes
Partial diversion trench in use
with limited success since 1983.
Conveys collected water directly
to NFHR. Synthetic liner and/or
stone lined flow channel resistant
to erosive forces of flowing water.
Chutes & Downpipes
Yes
"Integral part of diversion trench
system due to surface elevation of
Pond No.5. Concrete lined gabion
chute currently in use at the site.
Terraces & Benches
Yes
Potentially suitable for construction
in heavy wooded, steeply sloped up
slope area to convey water flow into
a lar~er diversion trench.
Seepage Basins
and Ditches'
No
Limited available space. Diverts
surface water to subsurface strats.
May increase water infiltration"of
slud~e and increase mercury flow to
~round water which discharges into
the NFHR.
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16
Excavation
The National Contingency
as a remedial option. At the
the excavation and removal of
yards of mercury-laden sludge
Plan requires that source removal be evaluated
Was t e Pond 5 sit e, source removal would i nvol ve
all or part of the estimated 4,000,000 cubic
currently impounded in a 79 acre pond.
Excavation and removal.of wastes and contaminated materials typically
involves the use of conventional heavy construction equipment and well-
esta~lished removal techniques. Table 3.6 presents a list of the construction
equipment commonly used for excavation and removal actions.
TABLE 3.6.
EXCAVATION AND REMOVAL EQUIPMENT
o Backhoe
0 Dragline
0 Clamshell
0 Scrapers
0 Industrial Vacuum Loaders
Upon completion of the preliminary screening process, it was determined that
source removal by means of full or partial excavation of the sludge blanket is not
an applicable remedial action technology for Waste Pond 5. Although two excavation
technologies (drag lines, dozers and loaders) are technically feasible, the potential
health risks posed by elevated mercury vapor concentrations during sludge excavation
justify their being eliminaced from further consideration as an applicable remedial
option. The short term risk outweighs the long term benefit.
A summary of the excavation technologies considered and significant screening
factors is presented in Table 3.7.
TABLE 3.7.
SUMMARY OF EXCAVATION TECHNOLOGIES SCREENING
Excavat ion
Technology
Feasible to
Wast e Pond 5
Significant Screening Factor
Backhoe
NO
Length of time required for
full/partial excavation
unsatisfactory. Potential adverse
health effects caused by elevated
mercury vapor concentrations
associated with sludge blanket
disturbances.
Drag line
NO
Potential adverse health effects
caused by elevated mercury vapor
concentrations associated with .'
sludge blanket disturbances.
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- --_.--~-------
17
Clams hell
NO
Specialized piece of equipment
not suited for high production
excavation.
Dozers and Loaders
NO
Potential adverse healfh effec~s
caused by elevated mercury vapor
concentrations associated with
sludge blanket disturbances.
Scrapers
NO
Better suited for removal/
grading of surface cover than for
excavation to depths required at
Salt vi lle.
Industrial Vacuum
NO
Better suited for liquid removal
than semi-solid/solid material
excavation.
pisposal
Onsite Disposal--
This option would involve removal of. the slud~e in Waste Pond 5 and
disposal elsewhere onsite.. The only area on Olin property that could contain
the waste is Pond 6. However, it is not likely that Pond 6 has the capacity
to contain. the large volume of sludge in waste pond 5. Even if it does, .
structural proble~s with the dike and underlying sludges are likely to
be encountered. Presently, Pond 6 has not been identified as a problem area
at Saltville. In view of this fact. it is reasonable to avoid disturbing the
material in Pond 6.
Offsite Disposal--
Landfilling is a commonly used technology for the disposal of haznrdous'
wastes. State-of-the-art RCRA landfill designs include double-liner systems
that have been demonstrated to provide adequate protection of the environment.
At Saltville landfills could be used to contain sludges if chese materials
cOllld be excavated from Waste Pond 5. However, th~re are a few waste
. characteristics that may make this alternative difficult to implement.
One of the most obvious characteristics that affects implementability 1s
the large volume of sludge that exists at the site. If 69% of the mercury
were to hp. removed from the pond. more than 800.000 cubic yards of material
would require disposal after excavation. The removal of ninety-two percent of
the mercury would require excavation and disposal of more than 2,200,000 cubic
yards and the removal of all of the sludge would require excavation and
disposal of more than 4 mi 111 on cubi c yards of sludge. To contai n the .sl:.udges
excavated from the pond. extremely large landfills. must be available or must
h~ built oftsite. t-~ost commerdal facilitit~s do not have the capacHy to
. manage such volumes of waste. Consequently it is most likely that an offsite
faci li ty t.ri 11 have to 'be built in order to implement this technology. Costs
-------
for building such a facility will be
of waste. Another characteristic of
is its water content. The sludge is
is saturated over much of its depth.
significant in view of the large volume
the sludge that affects implementability
reported to have a high water content and
Current RCRA regulations require that wastes containing fre~ liquids must
be dewatered or stabilized before land disposal. - Consequently, ~ll slud-ges
would have to be dewatered or solidified before disposal.
In addition, offsite disposal w1~hout treatment is the least preferred option.
Treatment (Wastewater Pond Discharge)
SARA requires that alternative technologies and resource recovery options be
assessed to the maximum extent practicable. In additon treatment technologies
should be considered. As indicated in Section 3 of the FS, the contaminant at the
site which is most toxic, and most mobile in the environment is mercury. Other
metals such as arsenic, cadmium and lead are also evident. However, since
mercury is the primary contaminant of concern, literature research for this -
task was focused on treatment technologies for the removal of mercury from
wastewater. Table 3.8 presents two remedial response actions that have been
developed for implementation at the Saltville site with a corresponding
compendium of liquid waste treatment technologies, assembled from lit~rature
reports, that have seen actual application to mercurybearing wastewaters.
Although Table 3.8 only presents demonstrated treatment technologies, it should
also be noted that emerging treatment systems which include combinations of -
the treatment technologies provided in Table 3.8, were also reviewed. These
systems are not discussed in this document because, in general, they have not
been demonstrated peyond the pilot-scale size and data is not available on
their cleanup level.
TABLE 3.8.
SALTVILLE WASTEWATER REMEDIAL RESPONSE ACTIONS
Remedial Response Actions
Treatment Technologies
Chemical/Physical Treatment of
Gnsite Contaminated Wastewater
Activated Carbon Adsorption, Chemical
Oxidation: Chemical Precipitation;
Chemical Reduction; Coagulation and
Flocculation: Electrodialysis;
Evaporation; Filtration; Flotation; Flow
Equalization; Ion Exchange; Oil separa-
tion; Reverse Osmosis Sedimentation;
Sludge Treatment; Ultrafiltration
Biological Treatment of Onsite
Contaminated Wastewater
Activated Sludge; Lagoons
Table 3.9 presents the results of the preliminary screening, with a
synopsis of significant screening factors. Upon completion of the preliminary
scre~ning process, it was determined that, as shown in Table 3.l0A, si-x.. -
technologies are applica~le as primary treatment technologies for remediation
of the Saltville wastewater. Table 3.108 lists technologies that are.
applicable as support treatment technologi~s potentially necessary to employ
in order to assume primary treatment ~ffective operation. As is evident from Table
3.9, no biological wastewater treatm~nt technologies are viable. Therefore, the
remdial respons~ action "Biological Treatment of Onsite Contaminated Wastewater" is
eliminated. -
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TABLE 3.9. SUMMARY OF REMEDIAL TREATMENT TECHNOLOGIES SCREENING
Remedial
Treatment
Technology
Feasible to
Saltville
Muck Pond No. 5
Leachate/Discharge
as a Primary .
Treatment
Technology Significant,Screening Factors
Applicable
Support
Technology
CHEMICAL/PHYSICAL
Activated Carbon Yes
Adsorption
Chemical Oxidation
No
Chemical
Precipitation
Yes
Chemical Reduction
Yes
Although more suitable for Yes
adsorption of nonpolar organic
molecular pollutants, Carbon
Adsorption has been retained
due to the great surface
affinity of mercury, and its
ability to function as a
combination filter/adsorber.
Mercury in Saltville wastewater No
has already been oxidized;
mercuric ion is more mobile
than lover oxidation state ions.
Precipitation of metallic No
hydroxides or suIfides is well
suited to Saltville1s inorganic,
soluble discharges. Quality of
residuals in treated effluent
and solid waste will influence
selection. Chemical precipi-
tation is often associated vith
oxidation or reduction processes.
Sulfide precipitation is better
for cblor—alkali point source
category.
Chemical Reduction is a well- No
developed technology. Sodium
borohydride process may be
capable of supporting mercury
recovery, but may introduce
undesirable chemicals into
effluents. Quantity of resi-
duals is less volumous than
other technologies.
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TABLK 1.9 (continued)
Remedial
Treatment
Technology
Feasible to
Saltville
Muck Pond No. 5
Leachate/Discharge
as a Primary
Treatment
Technology Significant Screening Factors
Applicable
Support
Technology
Coagulation/
Flocculation
No
Electrodlalysis
Yes
Evaporation
No
Fi1trat ion
Flotation
flow Equalization
No
No
No
Use of polymers and physical Yes
operations of coagulation/
flocculation will not address
the majority of mercury mass.
Although potentially effective
due to mercury surface affinity,
it is not as suitable as compe-
ting technologies, since it
focuses on colloidal mercury.
A good "support" technology.
Potentially applicable to No
soluble mercury. No chemicals
are added to waatevater by
process. Allows recovery of
mercury. Potential problems
with membrane fouling.
More suited for sludge treat- Yes
ment. Also, mercury volatility
would need to be addressed,
depending upon the heat rate
applied.
More suited to suspended solids. Yes
A good "support" technology.
More suited for colloidal or Yes
oily wascewater. A possible
"support" technology.
Not applicable as a primary Yes
technology. A good "support"
technology.
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TABLE 3.9 (continued)
Remedial
Treatment
Technology
Feasible to
Saltville
Muck Pond No. 5
Leachate/Discharge
aa a Primary
Treatment
Technology Significant Screening Factor*
Applicable
Support
Technology
Ion Exchange
Yes
Oil Separation
Reverse Osmosis
No
Yes
Sedimentation
No
Sludge Treatment
Ultrafiltration
No
No
Potentially applicable to Yes
largely soluble, inorganic
mercury vastevater. Potential
for mercury recovery exists.
Sensitive to fouling by sus-
pended/colloidal particles.
Only applicable to oily waste- No
water; Saltville waatewater has
no oil.
Reverse Osmosis may allow mer- No
cury recovery. Colloidal
fouling of the membrane may be
a problem; will need "support"
technologies. Addresses removal
of TDS.
Although an important "support" Yes
technology, it is not suited for
removal of colloidal or soluble
mercury. It is frequently used
on conjunction with precipitation
technologies for physical-
separation of precipitant* from
wastewater.
Not applicable as a primary Yes
technology. A good "support"
technology.
Ultrafiltration requires higher Yes
molecular weight solutes or
colloids beyond that of the
inorganic, soluble B.^rcury
complexes prevalent in the
Saltville site drainage/leachate.
It may be a potential "support"
technology.
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TABLE 3.9 (continued;
BIOLOGICAL
Feasible Co
Saltville
Muck Pond No. 5
Leachate/Discharge
Remedial
Treatment
Technology
as a Primary
Treatment
Technology
Significant
Screening Factors
Applicable
Support
Technology
Activated Sludge
No
Lagoons
No
Saltville wastewater is largely No
inorganic. Therefore, no carbon
source Tor activated sludge
processes. Also, Saltville
vastewater has a very high TDS
level which would impact micro-
bial viability.
Saltville wastewater is largely No
inorganic, with elevated TDS
levels. Lagoons primarily treat
organic wastewaters by oxidative
processes, with mercuric adsorp-
tion and absorption incidential
to organic treatment. Saltville
wastes cannot support this
microbial-based treatment process.
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TABLE 3.10A.
APPLIGABLE PRtMARY TREATMENT TECHNOLOGIES
Activated Carbon Adsorption
Chemical Precipitation
Chemical Reduction
Electrodialysis
Ion Exchange
TABLE
3.10B.
APPLICABLE SUPPORT TREATMENT TECHNOLOGIES
Activated Carbon Adsorption
Coagulation/Flocculation
Evaporation
Flotation
Flow Equalization
Ion Exchange
Sedimentation
Sludge Treatment
Ultrafiltration
Filtration
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19
Treatment (Waste Pond Material)
Enhanced Leaching--
Under current cond~tions, GCA has estimated that it may take thousands of
years for mercury to be completely leached from Waste Pond 5 by precipitation
falling on its surface. Enhanced leaching technology ofers a means to accelerate
the rate of leaching, -speeding the r~te of cleanup. This technology involves
application of reagents which will solubilize, and thus mobilize, otherwise
insoluble mercury compounds in Waste Pond S. This technology is currently in
the laboratory development stage (U.S. EPA, 1984), and is not knoWn to have
been used previously for cleanup at hazardous waste sites. Enhanced leaching
technology will be des~~iDed and its applicability for use at the Saltville
site assessed below.
Key parameters influencing mercury solubility include pH, oxidation-
reduction (redox) potential, and the presence of solubilizing ligands. At
acidic pH values and oxidizing conditions with moderate to high chloride
concentrations, soluble mercury can reach very high concentrations in the form
of HgC12 and HgC3. Addition of high concentrations of the ligand sodium sulfide
results in the formation of soluble polysulfide species. Other combinations of
pH, redox potential, and ligand concentrations can also produce high concentrations
of dissolved mercury.
Application of reagents at the Saltville site would probably be accomplished
through use of a spray irrigation system. The spray system network could be
floated out onto the pond surface using plywood mats to distribute weight.
Reagents would be mixed with water drawn fro~ the NFHR, and pumped onto the
pond surface via the spray system. The water/reagent mixture would then
infiltrate the sludge, displacing pore water through microscopic hydrodynamic
dispersionand thermal diffusion processes. This pore water exchange may be
maximized by maintaitdng sludge saturation between 85 to 92 percent. Ideally,
the reagent will then react with insoluble mercury compounds in the sludge to
form soluble compounds. The resulting solution containing dissolved mercury
will perco.late downward through the sludge unti i-t reaches -the water table.
Groundwater flowing down gradient will transport the solubilized mercury toward
the NFHR. A well point system located in pond 5 along and near the dike will
intercept the contaminated groundwater by creating drawdown in the water table,
preventing contamination from entering the river. -Water drawn from the pond in
this fashion will be treated in an onsite treatment system. Treatment system
effluent will be monitored for mercury and other parameters and discharged to
the NFHR.
The main advantage of i~plementing this technology is that, ideally,
the source of mercury contamination will be completely eliminated at com-
pletion of operation. Other technologies leave the threat of future exposure
and release of contaminants due to the continued presence of mercury i~ .
pond 5. There are, however, several factors which may prevent effective" -
implementation of this technology at the Saltville site, as well as possibly
" serious adverse impacts which may preclude adoption of this technology.
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20
A major factor in considering this technology is the potential for
serious adverse environmental impacts in the event of technology failure.
Should the well point contaminant collection system prove to b~ inadequate,
or should for any reason malfunction, a concentrated slug of so~ubllized
mercury would enter the NFRR. This would undoubtedly result in substantial
environmental damage, as well as greatly increase the current concentration
and extent of ~ercury contamination. Although the potential for system
failu~e may be low, it should ~arry substantial weight in consid~ration of
this technology because of the severity of the adverse impacts which would
result. . .
A problem involving the implementation of this technology may also
preclude its adoption. Application of solubilizing reagents may not be
effective due to the presence of large cracks and gullies in the waste
material in p~nd 5, some of which extend to depths of 10 feet. The majority
.of the water-reagent mixture would, upon application, travel downward through
the cracks because they are the path of least resistance to flow. Thus,
the reagents would effectively bypass much of the mercury contamination in
the top ten feet of sludge, precluding its solubilization and subsequent
removal. Rehydration or the surficial sludge by flooding Pond 5 would
require stabilization of the dike due to the added pressure upon it from
the additional water in Pond 5. It may not prove to be worthwhile to
stabilize the dike. if the amount of added effectiveness of flooding Pond 5
is unknown. .
The effectiveness of enhanced leaching is related to the extent to
which the reactions involved go to completion, and to the extent that.
soluble species of mercury are formed by each reaction. It may not be
possible to. lower the current pH of pond 5 (11 to 13) to a level necessary
to effect solubilization of insoluble mercury compounds because of the
large quantity of calcium carbonate (limestone) in pond 5. The calcium
carbonate would serve to buffer the pH, maintaining it at its current pH
despite the additon of acids. A problem regarding the metbod of adding
large quantities of sodium sulfide to form soluble polysulfides is that
large quantities of insoluble mercuric sulfide (HgS) would be formed as
well. Furthermore mechanisms describing any of these reactions are not
well defined in the literature indicAting a substantial degree of uncer-
tainty as to what products will be formed by any reaction.
In summary, enhanced leaching technology may result in serious adverse
environmental impacts, may be technically unfeasible to implement, and has no
been demonstrated to be effective. Therefore, at this time, this technology
is not recommended as a viable technolo~y for impleme'ntation of the Saltville
site.
. .
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21
In-Situ Chemical Stabilization--
Chemical stabilization involves the introduction into waste matrial 6f. a
chemical agent which combines with toxic materials to form compounds that are
not soluhl.~ in ~round water. The leachability of the waste is reduced because
the toxic materials are precipitated or otherwise immobilized. In-situ
stabilization involves introduction of chemical reagent into the intact
material of the waste s1~e by surface ~nfiltrat40n or injection.
Chemical stabilization of mercury wastes is a new and untested technology.
When Olin Corp. first proposed the in-situ stabilization approach, the
physical and chemical properties of the stabilization process were poorly
understo~c. The Olin Chemicals Process Division performed a series of
laboratory column tests to dentify potential reagents. The chemicals
tested were calcium sulfide (CaS), sodium thiosulfate (Na2S203).
These chemicals act by combining with mercury in the waste to form insoluble
complexes. The exact chemical species present in the untreated and treated
wastes have not been determined.
As a result of the Olin laboratory tests, sodium thiosulfate was
identified as the optimum stabilizing agent due to its rapid action, high
water solubility, low toxicity, commercial availability and low risk of
formation of polysulfide byproducts. .
The theoretical efficency of chemical stabilization with NaZSZ03 was demon-
strated by means of pilot-scale column tests in which the mercury concentration
in the column effluent wss reduced to approximately lUO ppb, or 5 percent of
the untreated level, by surface application of the chemical. .
Based on laboratory column tests, chemical stabilization appeared to show
promise as a remedial technology. However, field testing of in-situ
.stabilization revealed serious problems in applying tbis process at the
Saltville site. . Effluent mercury concentrations did not differ significantly
between treated and untreated test plots. The failure of the stabilization
process was attributed to channeling of treatment solution through cracks in
the solid waste material.
Based on the uncertainties involved with use of an unproven chemical
process, and the demonstrated inability of surface percolation or injection
to provide the requisite waste"reagent contact, in-situ stabilization does not
appear, at this time, to be a feasible technology for remedial action at the
Saltville site.
Above-Grade Ch:mical Stabilization--
Above-~rade stabilization involves the excavation of waste materials
from the contaminated site, and treatment of the waste by batch mixing with
a complexin~ reagent. The resulting material is less water-soluble than'toe
untreated waste, and therefore may be stored in a landfill with reduced risk
of leaching to ground water.
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22
The chemical technology used for stabilization of mercury wastes is
discussed above, under the heading of in"situ stabilization. Briefly,
so~ium thiosulfate (Na2S203) has been shown to be effective in reducing
mercury levels in leachate from Saltville waste, when tested in laboratory
and pilot-scale column experiments. The experiments were designed to test
the efficacy of in-sit'u treatment, and therefore do not address the situation
where waste and reagent are completely mixed. The effect of complete mixing
would probable be to shorten the required contact time and improve the stabiliz-
ation of the waste. However, differences in conditions such as the water
(".')ntent and oxygenation of the waste could have an unpredi ctable effect on
the complexi~g reaction.
The technology used in excavation, reagent application, and mixing of
the waste is well understood and in common use in chemical processing.
applications. The p~imary characteristic of the waste site that affects this
remedial alternative is the volume of waste to be treated. Pond 5 is
approximately 80 acres in area, and between 40 and 80 feet deep. The
ramifications of treating this huge amount of waste must be considered in a
detailed evaluation of the above-grade stabilization alternative.
Sediment Containment
Sediment containment is a general response action formulated for management
of migration of mercury contaminated sediments from the NFHR to the surface
water and to aquatic biota.
In responding to a situation where bottom sediments are contaminated
with hazardous substances, such as the NFHR, it is technically infeasible or
economically unreasonable to remove all of the contaminated material from its
location in the watercourse. If removal is determined to be an unacceptable
singular remedial response, in-situ control and containment measures are
often considered. These measures are intended to reduce dispersion and
leachi.ng of a hazardous substance to other areas in the water body. They may
be temporary or permanent response measures. The use of in-situ methods for
permanent containment of hazardous waste contaminated sedim~nts is neither
widely practiced nor well-demonstrated. Laboratory and pilot scale testing
is likely to be required before these methods can be implemented at a particular
site. Pe~nent containment methods may include use of dikes, caps, or in-
situ ~routing/sealing.
The potential appears to exist for deployment of dikes and in-situ
grounting/sealing, alone or in combination, to the NFHR sediments. Both
appear potentially technically feasible. However, as stated above the use of
in-situ methods for permanent containment of hazardous waste contaminated
sediments is neither widely practiced nor well demonstrated. Althougn dtilized
by 01in on a limited segment of the NFHR previously, no performance data has
been found documenting the efficiency of the technology. Additionally, caps
appear technically i~feasible due to the significant scour effects normally
associated with mountain stream environments such as the NFHR.
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23
Therefore, in the absence of laboratory
resulting data documenting the effectiveness
sediments, sediment contaminant technologies
consideration for the Saltville site area.,
and bench scale testing, and
of immobilization of Hg in
are screened from fu~the~
River Diversion
.Diversion of a watercourse is 'an established procedure using readily
available technology. Rerouting the existing NFHR would uncouple NFHR
sediments, the direct' source of mercury to aquatic biota, from the mercury
primary transport mechanism, surface water. Direct and indirect uptake by
aquatic rorganisms would thus be eliminated, reducing fish flesh mercury
concentrations.
Potential technologies for river diversion are:
Downpipes/Chutes
Diversion Trenches/Ditches
Berms/Dikes
Floodwalls/Levees
Downpipes/chutes--
It is technically feasible to size conduits to convey the entire tlow of
the NFHR at any point within the NFHR drainage regime. Run-on could be routed
to the conduits, which could be constructed directly on the existing riverbed
grade. However, a number of technical limitations preclude this option for
use on the NFHR. Groundwater and run-off would continue to recharge the
existing riverbed. This flow would would mobilize Hg, and if collected,
would need to be treated or discharged to the downpipe system; treatment of
flows averaging 300 cfs for low levels of mercury is not ,practicable.
Therefore, this technology would not isolate sediment Hg from surface water
and hence aquatic biota. Downpipe/chutes is thus not technically feasible
for application on the NFHR.
Diversion Trenches/ Ditches
Trenches and ditches could potentially be constructed adjacent to the
existing riverbed below river grade. This may intercept and drain away
waters making the existing riverbed, as well as intercept run-on from the
watershed. However, the presence of bedrock at river grade, coupled with
NFHR Valley topography rules out the technical feasibility of installation
of trenches/ditches below river grade adjacent to the NFHR at a capacity to
convey NFHR flows.
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24
Berms/dikes--
Berms/Dikes could potentially be used to direct existing river flow and
run-on from the existing riverbed to an alternate channel. The North Fork
Holston River valley topography is, however, characterized by steep slopes
with alternate channels not available without substantial earth moving. In
the event earth moving was successful, dikes/berms would not eliminate.
recharge of the existing riverbed without engineered measures such as cutoff
walls. The presence of bedrock at the river grade precludes use of these
measures. Surface water would thus be generated in the present river bed,
rendering the technology inapplicable for performance of its intended function
for NFHR Diversion.
Floodwalls/levees--
Floodwalls/levees are potentially applicable to NFHR river diversion in
support of rechanneling of river flow. However, as is the case with downpipes/
chutes, direct recharge of the present riverbed from ground water would
preclude the effectiveness of floodwalls/levees, which would contain the
river flow above the present riverbed grade. Use of sheet pile cutoff walls,
or other engineered measures is technically infeasible due to the presence
of bedrock at river grade plus the 80 mile length of river considered. This
surface water would still flow in the present riverbed. Floodwalls/levees
are thus technically inapplicable to the NFHR diversion.
Sediment Removal
Removal of sediments form natural water bodies and man-made inpound-
ments is an establish~d procedure using readily available equipment. As
indicated previously in this ROD, mercury, the contaminant of concern
at Saltville, has migrated offsite into the NFHR, and is concentrated in
river sediments that are the primary source of Hg for biota uptake. The
RA presented data that support the hypothesis that 0.5 ppm or less Hg in
sediments may likely lead to l~ss than 1 ppm Hg fish tissue levels; the 1 ppm
level will be adequate to safeguard human health. Additional data presented
'1n the RA indicated that sediments exceed '0.5 ppm Hg at all samplin~ locations
in the NFHR downstream of the Pond 5 outfall; this spans a distance of at
least 80 river miles. Sediment removal is thus a method of directly controlling
the contaminated sediment cur~ently in existence offsite.
Depending on the physical nature of the sediment, the depth of overlying
water, and the flow rate of streams and rivers, the following removal techniques
may be applicable:
o
Mechanical sediment removal
Hydraulic sediment removal
Pneumatic sediment removal
o
o
The NFHR constraints and Saltville FS constraints were identified, and
the technologies were screened, based on technical feasibility. Mechanical
sediment removal is a viable remedial technology for support of this general
. response action and is used in remedial alternatives formulation. Hydraulic
and pneumatic sediment removal technologies have be~n screened from further
consideration due to NFHR specific constraints.
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25
Remedial alternatives were developed to deal with the site by combining
those remedial technologies, discussed previously, into more specific remedial
alternatives. Remedial alternatives formulated are listed in Table 4.' The h
remedial alternatives were then screened on the basis of implementability, cost,
and effectiveness. The screening results are summarized in Tables 4.1 and 4.2.
Mechanical sediment removal, alternatives with waste water treatment by chemical
reduction, and combinations of management of mi~ration and source control remedial'
alternatives components (other than No" Act~n) were screened from further con-
sideration (For further detail on 'this screening refer to the Saltville FS, Chapter
4, pages 4-17 to 4-30.)
C.
Remedial Alternatives Considered in Detail
There are objectives of any remedial action(s) to be undertaken at the'
Saltville Site. The remedial action (s) must be consistent with the NCP and comply
with SARA. Subpart F of the NCP (Section 300.68) states that remedial action(s)
must contribute to an effective approach which will minimize and/or mitigate the
threats to public health,welfare, and the environment. Under SARA there are new
requirements to be considered in addition to the requirements of CERCtA for select-
ing the most appropriate remedial action for implementation.
The major new provisions added to the law
permanent solutions and a requirement that all
, legally applicable or relevant and appropriate
requirements (ARARs).
include a strong preference for
onsite remedial actions attain
Federal and state standards,
In addressing permanence"and long-term effectiveness of remedial actions
EPA must consider the following:
- long-term uncertainties of land disposal;
- goals and requirements of the Resource Conservation and Recovery Act (RCRA);
- reduction of mobility, toxicity, or volume;
- short and long-term potential for adverse human health effects;
- lon~-term maintenance costs and replacement costs;
- potential threat to human health and the environment from the excavation,
transportation, and redisposal, or contaminant of hazardous substances or
pollutants or contaminants.
SARA establishes a preference for remedial actions that utilize treatment
to permanently and significantly reduce the volume, toxicity, or mobility of
hazardous substances. Offsite transport and disposal without treatment is the
least preferred option where practicable treatment technologies are available.
For the purposes of this ROD, four alternatives incorporating the technologies
considered in detail were ~valuated for remedial action. These four alternatives
are as follows:
1 )
2)
No Action
Upgrade runon controls with ditches/berms/downchutes
, .
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26
3)
Upgrade runon controls with ditches/berms/downchutes and treat pond 5
outfall uJing either sulfide precipitation techniques or carbon
adsorption, and install ground water monitoring systems.
Upgrade runon controls with ditches/berms/downchutes, cap ponds with
synthetic membrane liner, install ground water monitoring system, and
treat outfall using either sulfide precipitation tech~ques or carb~n
adsorption. .
4)
Alternative 1:
No Action
The No Action Alternative is ~escr1.bed-and analyzed within for comparison
purposes with all other alternatives as required by the NCP. As its name implies,
the No Action Alterntive involves leaving the site as it currently exists with
no additional construction-type work to be performed within or outside the site.
However, the No Action Alternative considered in this document does include the
continuation (beyond April 1988) of all currently implemented remedial measures
specified in the "Special Order."
At present, the Saltville site and the NFHR (offsite area) have undergone
three remedial measures, as performed by Olin Corporation. All of these
activtties have been taken pursuant to the "Special Order" issued by the Common-
Wealth of Virginia. Specifically, the Va. SWCB issued this Special Order (dated
August 1982) to Olin Corporation concerning the mercury contamination problem.
The Order .(effective November 10, 1982 but which presently terminates on April 26,
1988) contained the following remedial action provisions (noted by bullets in the
text) which relate to the current No Action Alternative:
C)
Olin shall undertake and complete the diversion of surface water
runoff from the western portion of Muck Pond 5 by no later than
March 31, 1983 (the "Diversion Project").
A surface water runon diversion channel has been employed with some success
since April 1983 at Waste Pond 5. The channel, which receives storm water
runoff from a portion (104 acres, 75 percent of total drainage area) of the
steeply sloped and heavily wooded 139 acre-total drainage area watershed north
of Waste Pond 5, was constr.ucted on a clay-fill. bed and lined with an erosion
resistent synthetic liner in lieu of stone rip-rap. The existing channel was
not constructed to collect surface water runoff from the eastern end of the pond.
As such, only approximately 5S million gallons/year of the total 70 million
gallons/year of surface water that would drain onto the site is conveyed through
the existing channel structure. The remaining approximately 15 millton gallons/
year continues to drain onto the sludge blanket within Waste Pond 5 from culvert
A (not including the eastern area equal to 51 acres of drainage area), see
Figure 4.
Additionally, a sectio~ of the existing diversion system was routed directly
over a portion of ~he sludge hlanket along the northwestern corner of the pond.
On 14 February 1984, that section of the channel failed due to sludge settlement
below the clay bed. The channel was repaired on 17 July 1984. In April 1987, the
diversion ditch failed in several areas. EPA is organizing a sampling.effort t~
determine the extent of contamination by this release.
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27
As an additional part of the surface water diversion system constructed at
Pond 5 in 1983, a 5 foot wide, two-stage chute was constructed at .the southwest
corner of the pond to convey diverted water to the NFHR. The Cwo stages allow'
for wat~r drops of approximately 40 and 30 feet. The two stages are separated
by a stilling basin and 5 foot I.D. concrete culvert which conducts flow under
the existing access road. The chute was constructed with structually stable
g~outed ~abions which were then paved over with 3 inches of concrete to protect
against the erosion .forces of high velocity water flow.
o
Olin shall undertake and complete the removal of mercury contaminated
sediments from the subaqueous bed of the northern bank of that portion
of the river downstream from the Route 634 bridge to a point 1,000 feet
downstream by not later than December 31, 1982, and shall complete the
site capping and closure .of the soil disposal area by May 31, 1983 (the
"River Project"). A I-year extension was provid.ed if necessary approvals
.and permits were difficult to obtain.
The sediment removal action undertaken by Olin Corporation was completed b~'
January 25, 1983. In order to perform this activity, the NFHR was temporarily
diverted through the use of two. sandbag cofferdams and a diversion .flume located
in the riverbt!d. .This enabled excavation, with standard earthmoving equipment,
under dry conditions. Approximately 1,300 feet of the riverbed downstream of the
Route 634 bridge was isolated. An estimated 7,000 cubic yards of alluvial
mercury-contaminated material was removed. A layer of shotcrete was applied to
seal cracks and crevices if all contaminated material was unable to be removed.
.',
The work area was restored to its original contour and grade using crushed
stone. Material taken from the excavation was mechanically "treated" to
remove metallic mercury. Processed material was deposited on the old plant
site. A clay cap was installed over the old plant site and topsoil and grass
seeding was added along with a storm water diversion system to protect the
capped area.
Another project Olin performed during the summer of 1982 consisted of the
rip~rapping of a portion of the river bank adjacent to Waste Pond 5. This effort
was conducted in order to help stabilize the Pond 5 dike wall since extensive
erosion was jeopardizing the integrity of Pond 5. .
o
Olin shall commence a program of sampling of the mercury concentrations
in both the water column of the river and fish therein and shall maintain
a Sampling Program for a period of 5 years. Sampling shall commence upon
completion of construction of either the "Diversion Project" or the
"River Project", ~vhic.hever occurs first. .
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28
The last component of the proposed No Action Alternative involves the
current Sampling Program which requires the following activities to be performed
" -
by 011n:
1. . Fish--A minimum of one sample collection/year for 5 years (beginning In the
summer of 1983) with fish collection at each of the following river miles: 98,
77, 72, 59, 36, and 8.0. At least 15 sunfish, 12-20 cm in len~th, and 15 north-
ern hogsuckers, 23-3Z"cm in length, are to be"collected at each sampling site.
Each fish shall be analyzed individually for total mercury in edible muscle
using the EPA procedure. Twenty percent of all samples will be split ~th TVA
for analysis. Fish collection will be made by some method other than with
Rotenone.
2. Pond 5 Outfall--Daily flow measurements and samples of the outfall will be
collected daily (S days each week) and analyzed for mercury using the EPA cold
vapor procedure. The outfall will be sampled and ~nalyzed once each week for
TDS. Ten percent of the mercury samples will be split with TVA.
3. Instream--A minimum of three instream sampling studies are to be performed,
which will involve measurements of total mercury in water using the gold film
analyzer, similar in nature to the recent studies performed by Olin, to demon-
strate mercury concentrations in the river water. The portion of the river to
be sampl~d would extend from the Route 634 bridge to a point below the outfall
of Pond 5, to include the end of the concrete pad on the river bottom. Each
samplin~ study is to be performed every 2 weeks for a period of 6 months, March
though August, inclusive. The 2-week interval need not be precise provided"
that sufficient sampling at high flow is obtained. These three studies are to
be performed during the first 12 month period following the completion of the
in-river project, during the third 12 month period, and during the fifth
12-month period. Additionally, biota, both algae and invertebrates, are to
be analyzed for total mercury at the beginning of the fifth 12-month pe~iod
of study.
4. Rainfall Data--Rainfall data shall be provided with all sampling data.
This should include rainfall, before, during and after the actual sampling day.
S. Sediment--Sediment samples will be collected annually for S years at river
miles 98. 77, 72, 59,36, and 8.0. Three core samples should be collected acrcss
the river at each station, and the top inch of the three cores composited and
analyzed for total mercury. Samples should be collected during low flow perioJs.
All samples will be split with TVA. .
, .'
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29
Sampling results are suhject to the following sample analysis requirements.
1.
I!!h - Fish data will be evaluated following each annual ~ollection.
Pond 5 - Mercury and hydrological data will be evaluated semiannually until
a decision can be made regarding the effectiveness of the diversion ditch.
2.
3.
Instream - Instream studies will be evaluated following each 'of the three
studies.
4.
Sediment - Data evaluation following each sample collection.
In summary, the above implemented remedial measures are those actions taken
to date and which are proposed to be continued under the No Action Alternative.
In addition, the continued maintenance of all existing remedial engineered
structures (e.~., rip-rap riverbank stabilization, runon diversion, ditch/
downchute, cap on old chlor-alkalai plant site, plant site runon diversion),
plus all en!l;ineered structures whose failure would result in increased migration/'
transport of mercury to the environment, are included as components of the No
Action Alternative in this document. .
Performance. The performance of this alternative to effectively discontinue~
the release and/or migration of mercury contamination from the Saltville site is
at best questionable because current analytical results continue to demonstrate.
. the migration of mercury wastes from the Saltville site into the NFHR sediments
and biota.
-
Reliability. Based on the analytical results summarized in the RA, the No .
Action Alternative shows no demonstrated reliability to effectively minimize or
immobilize the mercury-contaminated materials.
.
Implementabilityo' Implementability of the No Action Alternative is not
applicable to the Saltville site because no additional remedial measures are
to be implemented.
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30
Safety. Safety co~cerns during the implementation of the No Action
Alternative are no greater than the present safety threats to the Saltville
community, nearby communities and the environment. That is, there will be
no elevated risk as a result of excavation and/or co~struction operati~ns;
however, the potential for exposure as a result of No Action has not been
reduced immediately.
The No Action Alternative aoes not limit or preclude exposure to mercury
via the.si~nificant exposure routes identified in the RA. Recent sampling data
(1985) indicate that .site conditio!ls remain-much the same in regards to the
contaminant levels detected in the sediments of the NFHR and discharge water
from Waste Pond 5. The concentration of mercury in the edible portion of fish
tissue remains on the average above 1 ppm. The area of the NFHR below the Salt-
ville Site is still being used by local residents for recreational activities
such as fishing, suggesting that exposure to mercury is ~ccurring. As concluded
in the RA, the ingestion of fish caught from the NFHR could lead to high mercury
exposures and present a significant risk to public health. The No Action alter-
native would not prevent continued human exposure to high concentrations of .
mercury via the in~estion of contaminated fish. The No Action alternative is
unacceptable in terms of improving and protecting the public health of persons
residi~ around the Saltville Site.
The No Action Alternative includes the continuation of the existing fishing
ban and sediment and fish sample anaylsis. This alternative repre3ents the
current conditions at the Saltville Site. Under the No Action Alternative the
Waste Pond 5 discharge is flowing at a rate or 0.05 cfs with an average mercury
concentration of 39 ppb and a peak of 120 ppb. The average daily flux of mercury
into the river is 10 g/day. Consequently, the current discharge mercury concen-
trations are not suitable for aiding in the depuration of mercury from aquatic
organisms in the North Fork of the Holston River.
The £i shi ng ban may help Umi t human exposure to contaminated fi sh, but
this action diminishes the recreational value of the river and requires constant
enforcement by state fisheries personnel. More importantly, complete compliance
of the fishing ban can not be assumed, suggesting that persons are being exposed
to significant levels of mercury. Under the No Action scenario conditions will
result in mercury fish tissue levels greater than 1ppm, and will continue to
adversely impact the intergrity of the aquatic ecosystem (decrease in species
diversity and vitality). The integrity of the aquatic environment of the
NFHR is dependent on sediment and surface water mercury concentrations being
maintained below the aforementioned criterion. Therefore, the No Action
Alternative is not effective in protecting the environment. The FS estimates
that this alternative would not have a total capital cost. However, annual
O&M costs would be 539,254 with a total present worth cost of ~370,044.
Alternative 2:
Upgrade runon controls with ditches/berms/doWt'chutes
. .
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31
""
Upgradi ng surface water runon cont rols for Waste Pond 5 at Saltville
is a very important remedial alternative component, and possible remedial
alternative alone, because of its ability to reducp the quantity of offsite
rai~fall (surface water runoff/runon) from entering the Pond and subsequently
infiltrating into the sludge material. The approach to runon controls, briefly
formulated in Section 4 of the FS and described in further detail below, is ex-
pected to be completely effective in eliminating runon for the 25-year storm.
In addition, the use of supplemental channel freeboard and design using conser-
vative runoff estimates will probably allow for reasonable prot~ction against
storms of longer recurrence intervals (i.e., 50-year and lOa-year storms).
As discussed earlier the runon control alternative is designed primarily
to intercept runoff from the approximate 35 acre Area A north of Pond 5"and
the 51 acre area east/northeast of the pond. Figure 4.1, presented earlier,
shows these areas and the approximate location of the new runon controls propo-
sed under this alternative.
A description of the runon control routin~ and construction can be found
in the FS on pages 5-7 to 5-11. Figure 4 is a conceptional design of the
surface water runon control system.
Pe rfo rmance--
The above described runon control system design is ~xpected to "be 100
percent effective in reducing runon to Pond 5 from the 25-ye~r storm. A lim-
ited amount of runon (less than 1 percent of the total) may result from the
area between the proposed collection system alignment and the edge of the
pond. No known site topography or geologic problems appear to be a major
factor in the effectiveness of this system.
The useful life of this system, with adequ~te maintenance, is expected
to be 30 years or longer. The drainage channel will have a longer life (SO to
100 years) with proper maintenance. The critical system elements include the
30-inch conduit and the gabion or concrete chute which may erode due to abrasion
or acid precipitation action. Neither of these eleme~ts will necessarily
require replacement after 30 years. However, some slight reduction in system
effectiveness may result.
-------
NEW
AREA A
NEW
EASTERN
AREA
AREA SERVED
BY EXISTING RUNON
CONTROL SYSTEM
_ . _-.?•_ _~3.-^. f in.
-_- V ' — — —%-——
PROPOSED ROUTE
OF NEW RUNON
CONTROL SYSTEM
FOR AREA A AND
EASTERN AREA
EXISTING
PARTIAL
RUNON
CONTROL .
SYSTEM
SCALE, FEET
Figure 4.1. Sketch of existing and proposed upgraded surface
water runon controls at the Saltvllle site.
-------
L f 0 t N D
CONTOUR GRADING
••I HOAO MCGNAOING SCdONS
H4+444 PMOPOSCO Of IH CHANNEL
im» morosio CULVENT
NEW EASTERN
AREA
EXISTING
CULVfMTS "A"
(APPHOXIUAIC
LOCATION I
NOT ONAWN TO SCALC
Conceptual design of surface water runon control system upgrade.
-------
32
Reliability—
The reliability of this system is judged to be high based on'-Che following"
factors: (1) use of simple principles and gravity flow ensures normal operation
most of the time; (2) minimal maintenance requirements; (3) few technical uncertain-
ties is underlying design; (•*) design for 25-year recurrence interval.
The probability of the 25-year design storm being exceeded during any given
year is I in 25. However, this exceedence will noc likely result in failure of the
system due to safety factors employed in the design. It is in fact likely that the
suggested design will handle the 100-year storm without significant failure. Thus,
the likelihood of failure may be more accurately stated as 1 in 100.
Iraplementability—
Based upon the proposed runon control alignment, which does not traverse
the pond sludge, the site conditions do not appear to have any serious impediments
to the constructability of this alternative. In general the excavation and
construction of the runon control system described above is fairly routine.
The most complicated element from the standpoint of constructability will probably
be the grouted gabion chute. The steepness on the slope, 1:2, may slow excavation,
hauling, and placement of the chute. In addition, the grade steepness may require
special means for placing the concrete grouting.
It is estimated that implementation of this alternative would be relatively
rapid compared with others being considered. Total implementation time is estimated
to be less than 6 months including: (1) 2 months for final design and bidding
specifications development; (2) 2 months for plan approvals and contract mobili-
zation; and (3) 2 months for construction of the runon control system.
During actual construction it Is recommended that construction of the grouted
flume be initiated first to allow adequate curing of the concrete. Further
construction programs should progress from the downstream elements in the upstream
direction to minimize delays caused by adverse weather and runoff. The construction
of the first element could be initiated at the same time as the flume since this
element will also require cast-in-place concrete.
Safety—
Unlike many other alternatives being considered, safety considerations for
implementation of this alternative are fairly routine. Since no excavation
on in the wastes will be required, no special protection should be necessary.
Also, since excavation cuts are relatively shallow (less than 10 feet) and side
slopes are generally flat (1:2), 10 special concerns regarding bank failure are
prominent.
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33
The proposed remedial measures designed to divert overland surface ~ater
flow away from Waste Pond 5 are expected to result in a decrease' in the discharge
flow (from 24 gpm to 18 gpm) from. this area into the NFHR. The average and peak
mercury concentrations in the outfall will likely remain at the No-Action levels
of approximately 39 ppb and 120 pp. Using these mercury concentrations and
flow rates in conjunction with the modeling results presented in the RA, it will
take a minimum of 14' years for mercury sediment levels to fall below 0.5 ppm.
In addition, mercury surface water concentrations will exceed 0.05 ppb during
periods of high discharge. These conditions will not result in a rapid depuration
of mercury from fish tissue to levels considered to be protective (1 ppm) to
public health.
Under this remedial alternatives ingestion of contaminated fish remains the
most significant route of exposure. The construction of the ditches, be~ms and
downchutes is not expected to result in worker exposure to mercury from direct
contact with contaminated 50ils or generate contaminated airborne particulates,
as construction will not be in an area of known contamination. However, certain
worker-safety precautions should be used (respirators, Tyvek suits) during
construction, as the proposed construction area is located very close to Waste
Pond 5 and other areas of contamination..
This remedial alternative does not provide significantly improved protec-
tion of the public health over a No Action alternative from exposure to mercury
contamination as levels of mercury in fish tissue are expected to remain above 1
ppm for a minimum of 14 years. Upgrading the existing runon controls will effec-
tively eliminate all overland surface water flow into Waste Pond 5. The reduction
in flow onto Waste Pond 5 will result in a decrease in the discharge flow at the
outfall area from 24 gpm to 18 gpm. This alternative provides no additional
benefit to the protection of the aquatic ecosystem over the No Action alternative.
The construction necessary for this remedial alternative should not.adversely
impact the aquatic environment at the NFHR. In addition, this upgrading process
would occur mainl~ on the side opposite the rivers ed~e offering little or no
adverse exposure to the NF~R. Although upgrading existing runon controls will
effectively eliminate all overland surface water flow into Waste Pond 5. The
continual loading of mercury into the NFHR. will not serve to effectively contri-
pute to the protection of the environment.
The FS estimates that this alternative would cost $50,052 with annual O&M
costs of $42,6~7; total present worth cost would be $452,459.
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34
Alternative 3: Upgrade runon controls with ditches/berms/downchutes
and treat pond 5 outfall using either sulfide precipitation techniques or
carbon adsorption and install ground water monitoring systems.
This alternative combines alternative 2 with treatment of pond 5 outfall and
includes a groundwater monitoring system. Since Alternative 2 ha~been discussed
previously, this section will focus on the treatment systems. The -'groundwater U
monitoring system will have to be designed after the conclusion of a hydro-
geological study at the site. It is proposed to reduce mercury discharge quantity
by either of three potential treatment alternatives as described in Table 5 and
depicted in Figures 5 through 7. Each provides for pH adjustment as a pretreat-
ment step, although this may not be necessary for the sodium sulfhydrate process.
Carbon filtration also requires up-front suspended solids filtration. Brine
(TDS . 10,800 mg/L) should have no effect on any chemical treatment alternatives
are essentially batch systems, while carbon treatment can be operated continuously.
A surge tank will be installed within the area of the current outfall structure
(within the lCGchate) while the existing concrete pipe will be plugged. The
leachate collected in the surge tank will then be pumped to pH ajustment tanks.
The waste pond itself will serve as an equalization basin, to provide regulation
of flow which ranges from 5 to 1,400 gpm over the year. Average flow is estimated
to be 20 gpm, with the majority of flows less than 100 gpm.
Table 5
TREATMENT ALTJ::RNATIVES
EVALUATED FOR THE SALTVILLE SITE
Treatment alternative
SolidR treatment mechanism
Dewatering
1 .
Sodium sulfhydrate
Sulfide preci pHation (Hg2+ to HgS)
Filter leaf
2. "Sulfex", or iron
sulf ide (Permuti t)-
Sulfide precipitation in solids
contact clarifier (Hg2+ to HgS)
Filter press
3.
Carbon filtration
Physical adsorption
None req ui red
Design flow is estabilished at 100 gpm (with two, 50 gpm parallel treatment
treatment ~ystems to be provided). These parallel systems ensure a partial
backup (to 50 gpm) in case one system breaks down, and allows cleaning and main-
tenance on one-half of system capacity without shutting down the entire system.
A 100 gpm design accommodates the majority of daily flows.
Chemical requirements and slud~e production were based on the average flow
'of 20 ~pm. Table 5.3 pres~nts estimated quantities of sludge to be produced by
each treatment process. Sludge will be considered hazardous because a waste
stream only 15 mg/Y in solids containing 39 to 120 ppb is coricentrated to a
minimum of 35 to 4) percent solids cake. For sulfide processes, much of the
sludge generated" ~ comprised of inert filter aid or nonhazardous sulfur
precipitate, but these sludges may still fail the ~P toxicity leaching test of
0.2 mg/L Hg. Since data is lacking, it seems prudent to adopt this approach as
-------
SODIUM
THIOSULFATE
H2 S04
SURGE
TANK
pH
ADJUST
pH
ADJUST
NaSH
REACTOR
REACTOR
PRES SURE
LEAF filTERS
"
Figure 5
(AS NEEDED)
HOlblNG
TANK
DISCHARGE
TO RIVER
PRECOAT TANK
(CELLULOSE TANK)
. .
HAZARDOUS SLUDGE-TO
RCRA LANDFill
Proposed sodium sulfhydrate precip1tation treatment system for waste pon~ No.5.
-------
SURGE
TANK
pH
ADJUST
TANK
SETTLING
TANK
SOLIDS
HAZARDOUS SlUDGE-
. TO
RCRA LANDFILL
Figure 10
(AS NEEDED)
DISCHARGE
TO RIVER
FILTER
PRESS
Proposed iron sulfide "Sulfex" precipitation treatment system for waste pond No.5.
-------
SURGE
TANK
(AS NEEDED)
pH
ADJUST
TANKS
Figure'
ENTIRE filTER
IS HAZARDOUS WASTE-
TO ReRA flLTftt
HOLDING
TANK
Proposed csrbon treatment system for waste pond No.5.
DISCHARGE
TO RIVER
, .
:
-------
35
the worst-case scenario.
TABLE 5.1
ESTIMATED SLUDGE QUANTITIES
GENERATED BY EACH REMEDIAL
TREATMENT ALTERNAT IVEI
ALTERNAT lVE COMPONENT
Process TPY Cu. ydlyr
NaSH 119 108
FeS 5.5 5.4
Carbon 11 13
Each system has two holdi ng tanks at the end of process' treatment which
at 36,000 gallons can hold up to 6 hours of maximum flow or 15 hours of average
flow. Treated effluent can be held in these tanks for testing prior to discharge,
ensuring that the mercury concentration limit has been met. Insufficiently'
treated effluent will be retreated.
Treatment facilities are proposed for location at elevations 1730 and
1740 between Waste Ponds 5 and 6 (Figure 8) at the Saltville site. Facilities.
for each alternative will require concrete foundation work covering aporoximately
100 ft x 100 ft, 30 ft x 50 ft of which will be enclosed by a metal-clad and
roofed building approximately 15 feet in height. It is assumed facilities
are supportable on the existing surface, which formerly supported railroad traffic.
A brief review undertaken on the g~otechnical stability of the Pond 5
dike revealed a stable condition for noroal situations. The stability of the
dike during earthquakes, flooding, and other natural events may be questionable
durin~ worst-case occurrences (FS Appendix 5), but those events would happen, at
l~ast statistically, at a time beyond the intended treatment system design life
of 15 years minimum. The proposed treatment plant location will be above the
estimated 100-year floodplain-of the river.
. .
-------
APPROXIMATE SCALE
EXISTING
OUTFALL STRUCTURE
Figure
Proposed treatment plant location.
-------
36
Performance--
Evaluation of performance of a given treatment alternative is based on.
consideration of its effectiveness and useful life.
Effectiveness--Leachate from S~ltville Waste Pond 5 is discharging to the
NFHR via a concrete outfall pipe. The pipe intake is located at an approximate
elevation of 1,676 feet .MSL, tbe lowest point of-the Waste Pond, hence serving
as a collection point for subsurface water accumulating beneath the entire sludge
pond. Discharge pipe invert elevation is 1,666 feet MSL.
It has been deterurlned by GCA Technology Division, Inc. that the current
avera~e mercury discharge of 39 ppb (peak discharge of 120 ppb) must be reduced
to a mean concentration of less than 20 ppb on a 24-hour basis for a minimum of
15 years. This standard is based on public health and environmental impact
considerations, and applicable or relevant and appropriate statutes. Based on
previous use and a review of literature, each of the treatment technologies
are able to reach the treatment goal of 20 ppb mercury discharge.
Useful life--The projected service life of component technologies varies
for each of the treatment alternatives. Some component technologies, such as
membrane separation equipment and carbon filters, require replacement at some
time during the project design p~riod of 15 years. Significant replacement
needs are identified below for each treatment alternative. All other equipment
will require only routine mechanical maintenance, which is not discussed.
o
Alternative 1: Sodium Salt Precipitation--Will usually require
replacement of filter leaf cloth every 3 to 5 years. Cloth is
readily available from a number of manufacturers.
o
Alternat i ve 2: .. Sulfex" (FeS) Process--approximat ely 20 percent of
individual filter press chamber plates will require replacement every
3 years. .
Q
Alternative 3: Carbon Treatment Process-Packaged carbon treatment
units will require replacement yearly over the project life.
Replacement media and housing are readily available from established
manuf act urers.
. -
Overall. no si~nificant differences in useful life is anticipated from any of
the three treatment systems evaluated above.
. .
-------
Reli abi li ty--
Reliability ~s an evaluation criterion of a treatment process' suitability
is concerned with its operation and maintenance (O&M) requirements and
demonstrated reliability at sites and conditions similar to the Saltville site.
QEeration and maintenance requirements--CERCLA guidance requires eval~ation of the
proposed treatment alternative on labor and materials availability ~nd their cost~, .
frequency, and complexity of O&M requirements. Alternatives needing frequent or
extensive O&M.are considered less reliable than technologies without these needs.
o hlt~rnative 1: Sodium Salt Precipitation--Based on a literature review,
discussions with vendors, design experience with similar systems for mercury
treatment, and a site visit to a chlor~lkali plant, this process is considered
readily operated and maintained by available labor at routine cost. No unusual
O&M activities relative to other technologies are required except for control of
hydrogen sulfide gas, which is generated upon low pH conditions in reactor tanks.
Use of sodium sulfhydrate (NaSH) instead of sodium sulfide (NaZS) practically
elimi nates thi s concern, according to the li terature and plant operato:':~, and is
also easier to handle and store than NaZS." This system is considered reliable.
o Alternative 2: "Sulfex" (FeS) Precipi tation--The Sulfex process developed by
Permutit requires more operator attention to ensure process effectiveness than
NaSH prec~pitation. More chemical storage, mixing and dispensing stages,and a
larger number of chemicals are also needed in the Sulfex process relative to
NaSH. However, filter aid is not needed at the solids dewatering filter,
because the Sulfex reactor has a high solids concentration which allowsb~~er
natural solids concentration. This contrasts with NaSH precipitation, which
requires two to three times more labor to backwash pressure filters to remove
accuJulated solids. This system is considered reliable.
~ .
o Alternative 3: Carbon Treatment--Activated carbon filters used for the mercury
feed stream will eventually diminish infiltration capacity and require yearly
replacement. Pretreatment filter cartridges also must be changed periodically,
e.g., monthly or quarterly. The pH adjustment system will require continual
operator attention and maintenance. The entire carbon treatment process will
require less O&M labor than any of the chemical treatment technolo~ies. O&M is
straightforward and relatively simple, in particular because the repiaced cartridge
filters and carbon filters involve modular units which are readily removed when
spent and rapidly installed when new.
In comparing the three treatment systems relative to reliability, it appears
as if the Sodium Sulfhydrate process might have the highest operation and maint-
enance (O&M) costs based upon the much higher volumes of sludge produced. However,
as the next subsection discusses in more detail, O&M costs for the "Sulfex" process
are similar because of the more complex treatment process which requires greater
operator attention. This, therefore, will likely offset the lesser sludge
handling and disposal requirements of the "Sulfex" and Carbon Treatment proce...ses.
In all, Carbon Treatment systems will still have lesser O&M requirements thar
either of the other two treatment systems.
. -
-------
38
Demonstrated performance--The probabili ty of the SUCCt"~S of each tech-
nology requires evaluation .based on an analysis of its historical performance
at similar sites or for similar wastes. A qualitative assessment ~f each'
technology requires evaluation based on an analysis of its historical performance
at similar sites or for similar wastes. A qualitative assessment of each'
technology's potential performance is provided below. .
a.
Sodium Sulfhydrate
This process has been used successfully for the past 2 years at LCP
Chemical in Orrington, Maine. Mercury concentration in the outfall
discharge is often nondetectable and generally doe~ not exceed 5 to
6 ppb. "The analytical limit of detection used to monitor the outfall
is 0.5 ppb.
No other system was reported in use in the literature. However, as
long as key process variables are carefully controlled (refer to
site visit notes in Appendix 3 of the FS), this process should be
successful at the Saltville site. .
This process is considered to be a demonstrated alternative.
b.
Iron Sulfide ("Sulfex")
This process has been demonstrated on many metal-bearing wastewaters,
primarily from plating and finishing operations. Curre~tly, over 80
Sulfex installations exist, and metal removals to less than 5 ppb are
typically being achieved for most metals. Permutit, manufacturer of .
the Sulfex process, has reviewed the Saltville leachate and feels
that its syst em is appli cable and can reach the requi red average"
discharge limit of 20 ppb.' As it does now for all its instal1.ations,
Permutit may be able to provide a performance gua~antee that it can
meet the 20 ppb limit. This guarantee is based on their experience
with mercury removal as one of many contaminants in a mixed waste
stream treated by Sulfex, and on an evaluation of expected Sulfex
effectiveness.
This process is considered to be a demonstrated alternative.
c.
Carbon Filtration
Discussions with Calgon Corporation, a major carbon media
manufacturer, have confirmed that mercury can be treated effectively
to the discharge limits required for this project. Calgon bases its
projections on current and past experience with remaining mercury at
similar or higher concentrations to those in the Saltville leachate.
This position agrees with the laboratory and pilot-scale testing
undertaken bv Georgia-Pacific for the EPA in 1974. Their work
found that mercury concentrations of 800 ppb and higher were
reduced to 10 to 20 ppb after carbon adsorption treatment.
From these con~iderationR, carbon filtration is deemed a
demonstrated technology.
-------
TABLE 4 . REMEDIAL ALTERNATIVES FORMULATED FOR THE SALTVILLZ
WASTE DISPOSAL SITE3
Management of Migration
A. Mechanical sediment removal
B. No Action
• Source Control
A. Upgrade runon control with ditches/berms
B. Upgrade rur.on control with ditches/berms, and treat pcnd outfall
discharge with chemical precipitation.
C. Upgrade runon control with dicches/benns, saa treat pond outfall
discharge with chemical reduction.
D. Upgrade runon control with ditches/berms, and treat pond outfall
discharge with activated carbon adsorption.
E. Upgrade runon control with ditches/benns and cap with
synthetic membrane liner and install ground water monitoring (gvm)
system.
F. Upgrade runon control with ditches/berms and cap with synthetic
membrane liner and treat pond outfall discharge with chemical
precipitation ana install gvm system.
C. Upgrade runon control wich ditches/benrs and cap wich synthetic
membrane liner and treat pond outfall discharge with chemical
reduction and install gvm system.
H. Upgrade nan on control wich ditches/berms :ind cap wich synthetic
membrane liner and treat pond outfall discharge wich activated
carbon adsorption and install gvm system.
I. Trsat pond oucfa^i discharge vith chemical rsduction.
j. Tr'-iac pond outfall discharge wich chemical precipitarion.
'<. Treat pone cv-.-.-fall diichar;e '»i;r. activated carbon adsorption.
L. ;ir> Action.
NOTE
"Management of migration can bs combined with each source control to formulate
11 additional remedial -. itarr.atives. •' •'.
-------
i-'iit «f. i SUMWV cf iFffmvtNEss
iot< OF Host KEUEOIAL ALTERNATIVES FORMULATED fdh THE SALTVHLE MSIF DISPOSAL SITE
Al lernat He
RtacMng 0.5 ppir
levels in Sediment
Reaching G.05 ppt
in Surface Water
Time Period
Expected to Achieve
Criteria Levels
• Impact to Result ii
Ecosystems from Fish Level
Implementing fit medial ---I ppm
Alternative metnyl mere
1. No Ait ion (Source Control hill not enhance
and M'ndgenunt of Migraticn) nepuiv.tion process
2, Upgrade Pt.non Contrcls
Controls
3. Upgrade ftunon Centre)
wiin Capptrg
Will not enhance the
dcpurat ion process
Will enhance depura-
tion proces by 30
peicent
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TABLE 4 ."3k ORDER OF MAGiNITUDE COST ESTIMATES OF THOSE REMEDIAL ALTERNATIVES
FORMULATED FOR THE S4LTVILLE WASTE DISPOSAL SITE
Coats Estimate3
Management of Migration
A. Mechanical sediment removal $669,089,000
v
B. No Action 624,000b
• i-
Source Control
A. Upgrade ran on control with ditches/berms 651,300
B. Upgrade runon control with ditches/benns, and treat pond 7,993,200
outfall discharge with chemical precipitation.
C. Upgrade runon control with ditches/beras, and treat pond 10,960,000
oucfall discharge with chemical reduction.
D. Upgrade runon control with ditches/berms, and treat pond 7,331,000
oucfall discharge with activated carbon adsorption.
Z. Upgrade runon control with ditches/berns and cap with 7,996,200
synthetic membrane liner and Install ground water
monitoring (gvm} system.
r. Upgrade runon control with ditches/berms and cap with 15,338,200
synthetic membrane liner and treat pond outfall discharge
wich chemical precipitation and install gvm system.
G. Upgrade runon control uith dinchas/cerns and cap with 18,304,900
synthetic mwmbrane liner and treat pond outfall discharge
with chemical reduction and install gvm system.
H. Upgrade runon control with Jitches/benns and cap with 14,675,900
synthetic membrane lir.ar and trea* pond outfall discharge
vi:h activ/ited c*rbr>n •id^orpcicn ana install gwm system.
I. Tr-sat pond outrali .ii 3. charge w'rii c:-,-jrical reduction. 10,932,700
j. Traat jond oucfall discharg; wich clic^.-cai precipicacion . 7,966,000
!'. ~.-eat pcr.-l o-jcf^li •iij-.-.-.a-^-i viuh aciivored carbon 7,303,700
adsorption.
L. t.'o .\ccion. 624, 000^
aCoatii updated anci discot;nC3c Co July 19C6. Values presentee are capital
cost? and O&rf costs (usinj a 671 di-; count rata;. ' ''
"Values shown ars similar sine': .he continuation of current No Action
vitirt? impact: bo:h irha ,;ourc2 -trd the M?HR.
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~9
Implementability--
The implementability of a remedial alternative is its ease of installation
or constructability and the time required to achieve a given levef..of response. --
Constructability--The constructability of a remedial alternative is
essentially the ability to construct or physically implement a practical
remedial alternative. For Saltville, this involves the construction of a
workable treatment syst~ on a given site adja~ent to Waste Pond 5.
Each of the three remaining treatment alternatives being evaluated (NaSH
precipitation, Sulfex precipitation, and carbon filtration) have similar
construction requirements. The site tentatively selected for construction of
the treatment facility (refer bacw to Figure 8) must be grubbed and graded,
For the first two t~chnologi~s, a concrete foundation will be poured for a
100 ft x 100 ft area, 30 ft x 50 ft of which will be covered by a metal-clad
and roofed building. The building will have small laboratory facilities,
certain critical equipment (such as pumps and chemical storage, and mixing
tanks which need weather protection), a storage and maintenance area, and an
administration/work office for a two-man staff.
The concrete foundation area for the carbon treatment alternative is
expected' to cover only 30 ft x 50 ft, one-half of which will support a
bui Idi ng of tbe type and funct! ons descri bed for the sulfur preci pi tation
alternatives.
, There are no known limitations to constructing any of the three treatment
alternatives on the site. Equipment to construct the plant and unit operations
for plant processes are readily available. Utilities (water and electricity)
exist at the municipal wastewater plant 100 yards southwest of the site. That
plant could receive sanitary discharge from the leachate treatment plant.
Time--The time to implement and the time to achieve beneficial results
are two crit,ical aspects of remedial planning.
Time to Implement--Vendor estimates and construction experience at
similar sites have been used to project the time of implementation
for each of the three proposed alternatives. Pilot testing of each
technology is anticipated to occur during the conceptual design
phase of work which follows this feasibility study. Jar testing
will be needed for each sulfur precipitation treatment method, and a
bench-scale carbon filter should be tested also. Testing results
will confirm the erfectiveneqs and cost performance of each
technology. Testing will probably require a period of 6 to 8 weeks
to complete.
Time to implement anyone of the alternatives is considered as the
time to purchase equipment, install shakedown, and begin full
operation of the treatment plant. It is expected that the minim~m
time required to accomplish these tasks will be as follows
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40
(excluding time for obtaining necessary permits, which is assumed to
be the same for each treatment alternative):
Technology
No. of weeks
Sodium sulfhydrate
24 - 40
"Sulfex" (iron sulfide) .
24 - 40
Carbon. filtration
1~ - 24
Sulfide processes will require the most time because equipment must
be purchased from a number of vendors. Additional time is spent in
preparing bid packa6cs and specifications for each vendor and in
ensuring that pumps, tanks, piping, and chemical feed systems, for
example, from different sources are well integrated. The "Sulfex"
process may require less implementation time because much equipment
is available from a single manufacturer who can also install the
treatment system. However, it will be considered to have a imple-
mentation time equal to NaSH to be conservative.
The carbon filtration technology is available from a single vendor.
Filters are kept "on the shelf" for immediate application and can be
dispatched to sites very quickly. Installation is rapid and relatively
easy. Construction of sitework, building, and surge and equalization
tanks and installation of utilities will require the most time for
implementation of this alternative.
o
Time to Achieve Beneficial Results
Mercury concentration in Pond 5 discharge to the river will decrease from
a peak of 120 ppb to below 20 ppb immediately upon full operation of any
one of the three alternatives. .
Safety --
Each technology was evaluated with regard to safety during construction
and operation. In general, the guidelines of EPA, OSHA, NIOSH, and the
U.S. Army Corps of Engineers will be followed during each stage of
remedial construction at the site in order to prevent safety hazards to
on-site workers. .
Construction accident r~sks will be limited to hazards typical in the
industry for work involving concrete sitework, building ~rection,
mechani cal ~qui pment i 'istallat ion, and ut i 11 ty servi ce connect ion.
Because the construction site is above the waste pond leachate by more
than 60 feet and no mercury vapor ~missions have been d~tected during
recent site visits, even on very hot days expected to release volatiles,
no contact with hazardous substances 1s possibly by workers except ofo.r
durin~ construction 'of the surge tank in the leachate and plugging of
the outfall ripe. Construction sitework will otherwis'~ occur in
noncontaminated areas. .
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41
No expod.Jre to
reaRent or chemical
review, none of the
filtration involves
materials.
the surrounding community should occur for any process
reaction occurring at the site. Based on the above
three alternatives poses an unusual safety haz~rd.- Carbon
the least exposure of workers to toxic or dange.rous
Upgrading runon control with concurrent treatment by either of the three
systems will result in a decrease in both discharge flow and discharge mercury
concentrations from the No Action levels. The.mercury concentration from the
Waste Pond 5 outfall will decrease to.below 20 ppb. At this mercury concen-
tration, the river surface water and sediment levels will approach and be
maintained at 0.05 ppb and 0.-5 ppm. The reduction in discharge flow and
concentration will result in a decrease in the flux of mercury into the
river from a No A::..ion average value of 10 g/day to 1.6 g/day.
Disturbances to the area around the Waste Pond 5 discharge will occur as
a result of the construction of a treatment facility. However the disturbance
is considered to have a negligable impact on the aquatic and terrestrial
ecosystems. COnsequently, the treatment of Waste Pond 5 discharge concurrent
with uPRradin~ runon control will be effective in reducing mercury concentrations
to levels considered protective of the environment.
Upgrading runon control with concurrent treatment of the discharge from
Waste Pond 5 will eventually result in a decrease in both discharge flow and
discharge mercury concentrations from the No Action levels. The flow rate trom
the Waste Pond 5 outfall will decrease from 0.05 to 0.04 cis with the water
heing treated to bring mercury concentrations in the discharge to J7 ppb, as
stated previously. At these discharge rates and mercury concentrations the
river surface water and sediment levels will approach and be maintained at
0.05 ppb and 0.5 ppm in a minimum of 10 years. The advantage of the treatment
alt~rnative over an alternative with no treatment is that surface water concen-
trations of mercury will not exceed 0.05 ppb.
The potential exposures via direct contact and inhalation during and after
construction c! the treatment facility are expected to be similar to the previous
alternative, with additional consideration for the construction and operation
of the treatment facility. The construction of the treatment facility will be
outside of Waste Pond 5, in an area of no known contamination. However,
construction of the surge tank and the plugging of the outfall pipe will occur
in contaminated areas suggesting that worker exposure to elevated levels of
mercury in 50ils and leachate 1s possible. The body dose levels of mercury
resulting from such exposure are impossible co esti~ate due to the limited
amount of scientific information quant1fyi~g the dermal absorption of mercury.
Construction of this remedial activity increases the chance of worker exposure
over the No Action al~~rnative mainly due to the construction of a surge pump
and plugging of the outfall pipe.
. The operation of the 'treatment facility introduces additional exposure to
other hazar.dous materials (process chemicals for pR adjustment such as H2S04.,
and NaOH) and the generation of potentially hazardous sludges. Laboratory
accidents, such as chemical spills are considered to present a potential for
exposure via direct contact with acids or inhalation of any gaseous fumes or
vapors. Additional risks incurred as a result of che operation of the treatment
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42
alternative include truck accidents resulting during the transportation of
the sludge to an offsite RCRA facility.
The F5 estimates that the cost of this alternative would r~nge-between --
the following:
Remedial alternative
Total Annual Present Total
capital O&M wo r t h present
cost costs of annual worth
($) ($) costs ($) ($)
860,052 245,687 1,946,407 2,R06,459
Upgrade runon control with
ditches/berms/downchutes and
treat Pond 5 outfall using
sod ill': ,:;ulfhydrate
precipitation
Upgrade runon control with
ditches/berms/downchutes and
treat Pond 5 outfall using
iron &ulfide (sulfex)
precipitat ion
2,143,052
219,687
1,750,407
3,894,459
Upgrade runon control with
ditches/berms/downchutes and
treat Pond 5 outfall using
carbon filtration.
840,052
182,687
1,469,407
2,309,459
This does not include costs for a groundwater ~onitoring system. These
costs will developed when further studies on the hydrology are completed.
Alternative 4: Upgrade runon controls with ditches/berms/downchute~, cap
pond 5 with synthetic membrane liner, install ground water monitoring system,
and treat outfall using either sulfide precipitation techniques or carhon
adsorption
Alternative 4 combines alternatives 2 and 3 and includes capping of Waste
Pond 5. Alternative 2 and 3 have been described previously, hence this section
will focus on capping. Capping is a very feasible remedial alternative component
(but not a remedial alternative alone) for Waste Pond No.5, because of its
potential. to prevent surface water infiltratio~ into the sludge and consequently
reduce the amount of contamination migrating to the NFHR. The approach to
capping formulated in previous sections is e~pected to account for settlement
and stabiU.:.y problems, and if implemented properly, is expected to be reasonably
effective.
The cover design is in compliance with RCRA closure and post closure
care requirements in that the cover is designed to:
Q
Provide long-term minimization of ~igratio~ of liquids;
Function with minimum maintenance:
Promote drainage; and
Accomodat~ settling and subsidence so that the cover's integrity is maintained.
. .
Q
Q
Q
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43
A cross-section of the proposed cap design is illustrated in Figure
9. In general, this cap design employs the use of a 100 mil (0.1 inches)
flexible membrane liner (FML) designed to cover the entire 70-75'.acre.s of
Waste Pond 5. Fill and geotextlle materials are 'also employed to"stabilize
the sludge .surface. The,cover will be sloped in general conformance with the
discontinuous or not consistent with the general slope, diversion pipes or
cha~nels will be placed over the,cover to convey the water. If-depressions in
the cover exist. pumping may be required to remove this water. The cover may
require reinforceme~t ~n those areas. The cap may be fitted with compensation
joints that will accomodate settlement if it oc~urs. A compensation joint
is an area where the liner material is folded. If tension is applied, the
liner will compensate by unfolding.
P~rformance--
The capping of Waste Pond No.5, together with upgraded surface water
runon controls, will minimize surface water infiltration which are both major
contributors to the cause of mercury contamination of the NFHR. A large
percentage of the water that seeps through the sludge and mobilizes mercury
comes from precipitation and surface water runon from upland areas. A
properly functioning cover will prevent some of this water from coming into
. contact wi th, the mercury sludge and therefore reduce the envi ronmental and
health hazard from the Pond. Peak mercury concentrations will be reduced.
Mercury flux will be reduced as well.
Capping will be particularly effective for the Waste Pond because most of
the mercury is located in the upper layers of the sludge (18 feet) above the
water table. Consequentlv, a large percentage of the water that comes in
contact with the mercury seeps down from the surface. Ground water base
flow accounts for the remaining flow out of the outfall, however, a ground
water study is necessary to determine the flow.
Si te condi tions that could potentia.Lly affect the performance of a cover
are sludge instability and settlement characteristics. As indicated in
Section 3 of the FS, there is great potential for the sludge to settle when
subjected to heavy loads. The cap design introduced in this study has been
tailored to accomodate these conditions. . The cap 1s lightweight and may be
fitted with compensation joints to accommodate any settlement that may occur.
Layers of fill and geotextile are included in .the design to add stability to
the sludge surface and bearing capacity to support the machinery used in
- liner installations. Additional geotextile material can be applied to areas
where additional support is needed.
When evaluating useful life, a number of factors must be considered. The
pria:..ry concern of liners exposed to the sun is degradation from ultraviolet
radiation. Schle~al has indicated that a liner manufactured with 2 percent
carbon black is expected to be sufficiently resistant to ultraviolet degrad-
ation. In addition, the thicker the liner, the less impact ultraviolet
degradation will have on liner integrity. Representatives of Schlegal'Lining
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44
Company have indicated that thick liners (i.e., 100 mil) instal~ed in arid
climates with prolonged exposure to the sun, have lasted up to 50 years
Schlegal indicated that humid environments are more favorable for liners.
Thus, it is conceivable that a thicker gauged liner installed in climatic
conditions characteristic of Virginia will remain structurally stable ror.at
least a SO-year period. At the end of this period, complete liner replacement
may be required.
Another consideration under tiseful life is the effect of continual stress
on the liner. Three conceivable occurrences could cause continual stressing of
the liner: '.
o
Ponding of water;
o
Differential settlement of the sludge; and
o
Ground subsidence due to water table lowering.
As stated earlier, the liner system is capable of enduring these stresses
for prolonged periods of time. However, it is conceivable that breaches could
occur. The advantages of leaving the liner exposed are that failures can be
quickly detected and the liner can be easily accessed for repairs. Thus, a
breach could be detected and repaired before unfavorable events occur.
Consequently, the useful life of the liner is prolonged due to the ease in
monitoring and repair of the liner. .
Reliability-
Flexible membrane Liners have gained widespread use as barrier layers in
the recent past. They have been installed in liner systems, under liquid
impoundments and disposal units, in cover systems over waste disposal units,
and other liquid and waste barrier applications. They have been demonstrated
to be effective in preventing migration of liquids. A flawless FML is
virtually impermeable. However, construction fabrication flaws are sometimes
unavoidable and therefore it cannot be assumed that FMLs are leak free.
Nevertheless, a well constructed FML can be an extremely effective barrier.
Exposed FMLs have been installed as covers over liquid impoundments,
reservoirs, and anaerobic digesters and have performed extremely well
Thick gauged FMLs (i.e., aOto 150 mil) have endured hot, arid climates for
periods of of up to 50 years.
Lining companies have installed thick FMLs as harrier layers over
anaerobic digesters. In these applications the liner is designed to conform
with the liquid level of the impoundment. The thicker gauges of FMLs have been
used due to their strength capabilities in accommodating the stresses resulting
from liquid level movement. These FMLs have been reported to perform extremely
well with little or no difficulties in these applications.
Geotext i les and it 11 layers have been used in many applications to' .eqhance
stability and improve bearing capacity underneath highways, along slopes under
-------
GRAVEL
FILL
" .
C~O ~/L. HOPE ~N:~ - --
-l;:-:-:-~~:-:-:-:-~~ :::GEOrEXrlLE .
. f!J5171///i
Figure '\
Cross-sectional view of proposed cap overlying
Waste pond No. S. .
. .
."
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45
wastes disposal units, etc.. It is expected that the support layer design will
be sufficient to support machinery used in liner applications. Where_extremely
soft sludge is encountered, addi tional layers of geotextile may be"" used to enhan"ce-
stability. .
Operation of the capping sys~em may involve surface water pumping if depressions
in the liner system are evident and prolonged ponding occurs. Continual monitoring
of the site will be reqqired to scan for tear~ or breaches in the liner.
Maintenance may be required if breach-es or tears occur or if the slope of the
surface water conveyance system is disturbed. -Maintenance will involve relatively
simple liner patching activities and reassemblement of the pipe system.
Operation (i.e., pumping of surface water) of the site could occur rather
frequently during winter and spring months if ponding of water occurs. However,
the pumping activities would be rather simple because water would only be pumped
to the perimeter run-on control system or one of the main surface water conveyance
pipes installed over the liners. Monitoring of cap integrity should be rather
frequent (i.e., monthly) so that failures can be detected and repaired expeditiously.
Implementability--
Construction of the cap will be complicated by the settlement and
stability characteristics of the sludge. Extreme precautions will have to be
taken to avoid disturbing the sludge. Stability problems were encount~red
during and after the construction of a portion of the runon control system
over the sludge. However, by using careful techniques, the const'ruction was
somewhat successfuL The contractor placed a geotextile over the surface of
the sludge to attempt to stabilize the surface. Subsequently, layers of the
r~non control system were placed in thin lifts to avoid substantial disturbance.
Precautions were taken to avoid inducing substantial machinery loads on the
syst em.
Similar precautions should be taken during installation of the cover
system. The layers of fill and geotexitles are expected to provide sufficient
bearing capacity and stability enhancement for construction activities.
Substantial machinery loads should be avoided over the softest portions of the
site (Le., the westerly and central portions). In these areas it may- be more
feasible to manually install the FML. Schlegal has indicated that the liner
material can be manufactured in smaller, more manageable rolls. Additional
layers of geotextiles may be placed if additional support is needed.
It is conceivable that construction will be prolonged due to difficulties
encountered during construction. Installation of a liner over a stable foundation
could be accomplished in approximately 1 month. However, the structual
difficulties associated with Waste Pond No.5 could prolong construction from
2 to 3 months. This accounts for time to install the fill and geotextile layers.
In addition to construction difficulties, contigencies such as adverse weather -
conditions must be considered. Liner manufacturers recommend that liners not
be iostalled in windy, wet, or cold weather(temperature below 40°F are unfavor-
able). It is probable that all or some of these conditions will persist
throughout the year (particularly winter and spring). Thus, time must be set
aside i9r these contigencies. Schlegal estimates that at least 2 to 3 weeks
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46
be set aside to account for weather contigencies. Baserl on the above tlm~
estimates, it appears that installation of a cap over Waste Pond 5 could take
take from 3 to 6 months.
Beneficial results may not be seen immediately after this technology is
implemented. Results of concentration monitoring of the outfall after the
c.onstruction of a runon control system sulltge!'Jts that there is at least a
6-month lag in time to see beneficial results. The lag exists because of the
time it takes for.wa~er to infiltrate throu~h the sludge. Thus, it is.
conceivable that beneficial results will not be seen until 6 months after
construction.
Safety--
There are no major safety-related issues concerning threats to nearby
communities and the environment. Threats to the environment are not expected
to increase during implementation of this alternative. Worker potection in
accordance with OSHA must be instituted during cap construction (particularly
during installation of geotextile and fill layers). Extreme care ~ill have to
be taken when drivin~ heavy construction machinery over the sludge to avoid
stability failures and vehicle accidents.
Risk from exposure to mercury via direct contact with contaminated soils
or leachate was considered possible for workers during the construction of the
cap and treatment facility. Additionally, exposure via inhalation of
contaminated dust or vapors generated by ~hese construction activities was
considered possible for area residents. Exposures via these two routes are
considered to be temporary, lasting only for the duration of the construction
period. Once the cap is in place exposure via direct contact or inhalation
will be significantly reduced.
The treatment alternatives present additional risks from exposure to
process chemicals and hazardous slud~es. The risk to the operators of the
treatment facility will continue for the duration of treatment operations.
Truck accidents resulting from the transporation of hazardous sludges to an
offsite RCRA facility is considered to present an insignificant risk.
The treatment of Waste Pond 5 discharge water in addition to upgrading
runon controls and the placement of a full syn.thetic flexible membrane cap
over Waste Pond 5 will result in a decrease in the mercury concentrations to
approximately 69 ppb. The resultant flux of 0.118 g/day mercury into the
river will result in approaching and achieving mercury concentrations of
0.05 ppbin surface water and 0.5 ppm in sediments. At those levels mercury
levels in fish tissue will fall below 1 ppm. Disruption of the area around
Waste Pond 5 will result during the construction of the treatment facility and
placement of the cap however this disruption to the terrestrial and aquatic
ecosv~tems is considered to be negli~ible. The treatment of Waste Pond 5
dischar~e concurrent with upgrading run-on control' and the placement. of a full'
synthetic flexible membrane cap will be effective in protecting the
envi ronment.
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47
The FS estimates that the COgt of this alternative would range hetween
the following:
Total Annual Present Total
capital O&M worth oresent
. cost costs of annual worth
Remedial alternative ($) ($) costs ($) ($)
Upgrade runon control with 8,455,035 405,922 3,456,927 11,911,962
ditches/berms/downchutes,
cap Pond 5 with synthetic
membrane liner, install
ground water monitoring
system, treat outfall using
sodium sulfhvdrate
precipitation
Upgrade runon control with 9,738,035 379,922 3,260,927 12,999,962
ditches/berms/downchutes,
cap Pond 5 with synthetic
membrane liner, install gwm
system, treat outfall using
iron sulfide (sulfex)
precipitation
Upgrade runon control with 8,435,035 342,922 2,979,927 11 ,414,962
ditches/berms/downchutes,
cap Pond 5 with synthetic
membrane liner, install gwm
system, treat outfall usin~
carbon filtration
. .
)
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48
Recommended Alternative
Section 121 of SARA adds a new section to CERCLA that establishes a
variety of requirements relating to the ~evel of cleanup for rem~ia~ actions
under CERCLA. This section codifies many of the existing requirements under
the NCP, but also establishes additional directions for selecting permanent
remedies and for meeting state requirements (ARARs - listed in "I'.:ble 2).
The basic requirements for a selected remedy are that the remedial
act ions be: ".
1 )
2)
3)
4)
Protective of human health and the environment;
Cost effective;
In accordance with the NCP; and.
In accordance with new SARA provisions.
Consideri ng the current and potential site hazards, the recommended alternati ve
is alternative 3. Alternative 3 has been chosen as a interim alternative due
to the studies still needed to define the extent of contamination. This
alternative consists of upgrade runon control with ditches/berms/downchutes,
treatment of Pond 5 outfall, and grounwater monitoring. In addition to this
interim remedy, a groundwater study, bioassessment, and additional sampling
along the NFHR need to be implemented. Once these studies are complete, a
final remedial action could be developed. It should be noted that an interim
alternative does not have to comply with all SARA requirements. However, this
interim alternative does make use of treatment options.
The No Action alternative is not effective in mitigating the mercury
exposed hazard to the environment at the Saltville Site. Under the No Action
alternative, mercury concentrations in the sediment will remain above O.Sppm
and mercury surface water concentrations will exceed 0.05ppb at certain times
of the year. These envi ronmental condi tions wi 11 result in mercury fish tissue
levels greater than Ippm, and will continue to adversely impact the integrity
of the aquatic ecosystem (decrease in species diversity and vltality). The
concentrations of 0.05ppb in surface water and 0.5ppm in sediments.
Consequently, these alternatives contribute to the effective and timely
cleanup of the aquatic environment at the Saltville Site.
Comparison of Alternatives and Consistency with other Environmental Laws
Alternative 1
The No Action Alternative is required by the NCP, 40 CFR 300.68, to be
developed and considered as part of the CERCLA. The No Action Altern;.i:ive
developed for the Saltville Site consists of continued compliance to :he
Special Order (issued by the VSWCB to Olin Corporation on August 198~), continued
monitoring and analysis of fish, and river sediments and water, maintenance
of existing onsite runon control structures, and site security.
This alternative does not meet the goals of the NCP which are to minimize
or mitigate threats to the human health and the ~nvironment and provide
adequate protection of human health and the envi ronment. Fish and fresh water
- in the NFHR will continue to receive mercury-contaminated wastes.
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49
The No Action alternative is not in compliance with applicable
State RCRA closure/post closure requirements (40 CFR 264 Subpart G)
address groundwater contamination (264 Subpart F). I~ is presently'
what e~tent g~oundwater is contaminated. .
Federal and
and does not
unknown to
Alternative 2
. . . .'
This alternative appears to help minimize threats to the environment through
a moderate reduction of the flow of contaminated effluent from Waste Pond S to
the NFHR. This alternative does not, however, appear to provide adequate
protection of the environment because the untreated, contaminated effluent will
continue to enter the NFHR at only a slightly reduced volume. This alternative
is not in compliance with applicable Federal and State RCRA closure and ground-
water monitoring requirements at 40 CFR 264 Subparts G aua F.
Runon controls should be upgraded in compliance to RCRA specifications.
State standards appear to be equivalent to the Federal RCRA standards.
Appropriate and relevant requirements include 40 CFR 264.301(c) for landfills
and 264.221(d) for surface impoundments. Under 264.301(c), the runon control
system must be designed, constructed, operated, and maintained to prevent flow
onto the active portion of the landfill during a peak discharge from at least
a 25-year storm. Under 264.221(d), surface impoundments a~e required to have
dikes that are designed, constructed, and maintained with sufficient integrity
to prevent massive failure of the dikes. The runon control system specified
in this alternative is designed to w{thstand at least a 2S-year storm and the
associated dikes are designed to have sufficient structural integrity. Runoff
controls and associated collection and holding facilities are not applicable
nor relevant and appropriate requirements to this alternative at Waste Pond S.
The purpose of runon control is to reduce the amount of water reaching the
Waste Pond and to reduce the amount of contamination run-off generated. The
runoff resulting from diverting runon onto the Pond will remain uncontaminated
and will flow naturally into the NFHR. Although the upgrading of runon controls
does not appear to involve direct contact with the contaminated wastes, OSHA
should be consulted for proper worker safety and health guidance prior to
commencing any work at the site.
Aside from specified detection and compliance monitoring programs in
Subpart F, corrective action requirements at 264.100 may also become applicable
or relevant if groundwater contamination is evident. Under the RCRA regulations,
corrective actions must attain a groundwater cleanup standard established for
each facility. For a limited number of potential contaminant~, a standard is
specified in the regulations at levels corresponding to National Interim primary
Drinkin~ Water Standards (NIPDWS) developed pursuant to the Saf~ Drinking Water
Act. 40 CFR 141.11 specifies ,maximum contaminant level for mer~ury of 0.002
mg/L. In the absence of an ACL or a standard based on Safe Dr~nking Water Act
determina~ions, the groundwacer protection standard of 0.002 mg/L mercury
(264.94} is considered a background level. It should be noted that the State
of Virginia has specified a more ~tringent Met for mercury'at 0.0002 mg/L co
protect groundwater (Section 10.060.05 of the Virginia Hazardous Waste Management
Regulations).
-------
50
Alternative 3
The influent to the proposed treatment fa~;lity (i.e., the existing Pond
5 discharge) is a RCRA hazardous waste (40 CFR 261.3(c)(2». In addition,
wastewater sludge or spent carbon generated by the treatment process may be
considered a characteristic RCRA hazardous was:e, since. its expecte.~ mercury
concentration is sufficiently high to cause it to exceed the EP toxicity limit
for mercury ,0.2 mglL .(40 cn .261.24).
Construction and operation or the treatment facility must be in
compliance with RCRA facility standards and administrative requirements for
hazardous waste storage,' treatment or.disposal -facilities under 40 CFR Part
264 Subparts A through H. The treatment facility will be designed and
operated in accordance with these requirements. Performance aspects of the
.treatment facilitv will be regulated under the Clean Water Act's NPDES prog~am
governing wastewater discharges, as discussed below. and will not be regulated
under RCRA (40 CFR 261.4(a)(2».
Sludge or spent carbon generated during the t~eatment process will be
temporarily stored on-site while awaiting off-site transport and disposal.
Sludge or soent carbon will not be stored on-site fo~ more than 90 days.
Therefore, according to 40 CFR 262.34(a), the on-site storage of these
hazardous wastes will not require a RCRA permit. Rowever, they must be
stored in ~ompliance with the requirements of 40 CFR Part 265 Subpart I
(interim status standards for storage of hazardous wastes in containe~s).
These requirements are ordinarily administrative in nature and do not impose
stringent design standards on sludge storage facilities. . They will be
complied with through proper recordkeeping and operation of the storage
facility.
RCRA regulates the off-site transport of hazardous wastes through the
adoption of certain DOT re~ulations governing the transport of these wastes.
RCRA hazardous waste transport regulations are ~pecified under 40 CFR Part 263
and encompass transporter identification numbers, manifests, recordkeeping and
hazardous waste discharges during transport. The off-site transport of
hazardous sludge or spent carbon from the Saltville site will be performed in
DOT-approved transport containers by a commercj~l hauler having an EPA
transporter identification number. In this manner, the off-site transport of
wastes from the Saltville site will be performed in compliance with the
Part 263 requirements.
In accordance with the NCP and specified under 40 CFR 300.68(a)(3),
'off-site disposal of hazardous wastes removed from CERCLA sites can only occur
at facilities that are fully permitted under appropriate federal and state
regulations (i.e., a fully permitted RCRA facility). The hazardous sludge or
spent carbon transported off the Saltville site must b.~ disposed of i.n such a
faci.lity. A fully-permitted RCRA disposal facility tt: it will accept the
mercury-contaminated sludge or spent carbon from the ~altville site has not
been identified as part of this study. However, commercial RCRA landfills
only access wastewater sludges for disposal, depending on the solids
content and chemical make-up of the sludge. It is not expected that this
sludge area is hazardous to health. . a'
-------
51
issue will significantly impact implementation of a treatment alternative,
although the time required to implement the alternative may be le~gthened if
it is difficult to locate a permit te~ landfill- that will accept th_e waste from --
the Saltville site.
. -
tind-e-r Se:ct ion 40'2 - ~'f - the- Clean t-Tat~t' Act, the Federal government has
authority to regulate wastewater-discharges through the NPDES permit program
(40 CFR Part 415 Subpart F). The State of Virginia is authorized to
administer the NPDES perIni t program at the State l~vel.
It is assumed that the NPDES permit for the discharge will set a limit on
the concentration of mercury in the discharge in order to achieve the water
quality standard for mercury of 0.05 ppb ir the NFHR. Allowable mercury
concentrations in the treatment process effluent have been estimated by GCA
based on the modeling of mercury loading to the river. Based on vendor
information, the three treatment alfernatives under consideration are capable
of generating an effluent in which the concentration of mercury will be
within the allowable limits. Therefore, it is expected that the Saltville
treatment f~cility will comply wit~ the mercury dischar~e requirements of
its NPDE S pe rmi t. -
Federal requirements under Executive Orders 11988 and 11990 governing the
impacts of activities on floodplains and wetlands are applicable to certain
portions of the Saltville site. However, since the proposed treatment
faclli ty will not be const ructed on those portions of the si te designated as
floodplains or wetlands, these requirements will not impact implementation of
a trp.atment alternative.
Treatment system effluent will be discharged to the NFHR. Construction
of the di ~charge out fall wHl not phy~i cally modify the NFHR. It is assured
that water quality will also not be modified as long as NPDES discharge permit
requirements are complied with. Therefore, requirements of the Fish and
Wildlife Coordination Act, et al., will not impact the implementation of
treatment alternative.
OSHA requirements for worker health and safety are applicable to
construction and operation of the treatment faciU ty on- the site. During
th~se activities, workers will come into contact with and handle hazardous
substances such as the influent to the treatment facility and the sludge or
spent carhon generated by the treatment process. Proper worker health and
safety practices will be instituted during the facility's construction and
operation to comply with OSHA requirements. Thus, OSHA requirements will not
s ignifi cantly impact implementation of a t re.(tment alt~rnat i ve.
The Hazardous Waste Management Regulations administered by the State of
Virginia (Chapter 6, Title 32.1, Code of Virginia) are essentially equivalent
to Federal raqufrements under RCRA. Thus, the impacts of the Virginia
~3zardous waste Management Regulations on implementation of a treatment
~lternative are the same as those related to RCRA regulations, as pre~lously
elf scussed.
-------
52
Under the CWA, the Fed~~al government has authorized the State of
Virginia to promulgate enforceable water quality standards. As a result, the
Va. SWCB administers the Virginia State Wate~ Control Law. Und~r t~is law, the
State has set a wacer quali~y standard for total mercury in fresh water "of
0.05 ppb. This standard will be enforceable for the NFHR in January 1987. As
a result, "the discharge of treatment process effluent to the NFHR must not
cause total mercury concentratl~ns in the river to exceed the 0.05 ppb limit.
Construction of the treatment facility on the Saltville site must be
approved by the Saltville Town Council and variances to local zoning
ordinances may be required for the facility. No other local requirements have
been identified as pertinent to a treatment alternative at the site. Town
Council approval for the facility and any needed variances are not expected to
interfere with implementation of ~ treatment alternative. .
Alternative 4
This alternative appears to minimize threats to the environment through a
lar~e reduction in the flow of cQntaminated effluent to the NFHR. Less water
will be allowed to run onto the Pond and mix with the mercury-contaminated
sludge, therefore reducing the amount of contaminated runoff generated. The
institutional issues and considerations for the second remedial alternative
also applies to the runon controls specified in this alternative.
Capping will further minimize the amount of runon, and hence minimize
the amount of contaminated run-off to the NFHR. . The installation of a cap
appears to effectively minimize the flow of contaminated effluent from the
Pond to the NFHR which will result in a reduced impact to the environment. As
stated in the previous analyses of alterna~ives, human health is not currently
an issue at the Saltville sit~. Because this alternative proposes to close
the Pond with waste left on-site, both landfill and surface impoundment
closure requirements become applicable. The proposed cap is equivalent, as
technically feasible, to applicable RCRA landfill and surface impoundment cap
design requirements (40 CFR 114.228(a)(2)(ii) and .310) and EPA guidance.
State standards for final covers are equivalent to Federal RCRA standards.
The proposed cap will provide long-term minimization of migration of liquids
through the closed landfill/impoundment, function with minimum maintenance,
promote drainage and minimize erosion or abrasion of the covers, and will
accommodate settling and subsidence so that the cap's inte~rity is
maintained. Prior to capping, all free liquids must be eliminated by removing
liquid wastes or solidifying the remaining waste and waste residues, and
remaining wastes must be stabilized tn a bearing capacity sufficient to
support: a final cover (264.228(a)(2)(ii». Due to the nature of the wastes in.
Pond 5 a true RCRA cap design as spe ified in EPA guidance document on
"Landfill Design Liner Syst~ms and Final Cover", July 1982, was not
t~chnically feasible. The proposed cap contains ~everal layers with a
flexible membrane as the final cover. Due to the instabili~y of the wastes,
no soil or vegetation was proposed. Runon wi 11 be di rected by lateral." ..
branches on top of the flexible membrane and pumped out of the Pond area and
into the NFHR. The runon and runoff control systems and proposed
-------
53
maintenance appear to be in compliance with applicable RCRA landfill and
surface impoundment requirements specified at 40 CFR 264 .228( b) and
.301(d)(e), and 264.310(b).
This alternative proposes to implement RCRA closure and post-closure
requirements in compliance with applicable RCRA regulations at,~O CFR 264
Subpart G. State closure standards appear to be equivalent toCthe-Fed~ral
RCRA closure standards. Section 264.111 of Subpart G specifies that the
,faciU ty 'mus~, be ,~lose~ ,in a ,manner. that minimizes the need, for further, "', " ,
maintenance, and contruis, mdnimizes or eliminates, to the extent necessary to
prevent threats to human health and the environment, post-closure escape of
hazardous waste, constituents or leachate to the ground or surface waters or
the atmospheres. 'All faciU ty eq~ipment and structures must be properly
disposed of or decontaminated following closure (264.114). An independent
registered professional engineer must certify that the facility has been
properly closed (264.115).
, .
Section 264.117 s~ecifies a post~closure care period for 30 years during
which applicable monitoring and reporting requirements must be complied with
and post-closure use of the property must never be allowed to disturb the
integrity of the firial cover. Sections 264.119 and .120 require the loca~
land authority to be notified upon closure and a specified notice to be
inserted in the deed to the property. The implementation of a RCRA
closure/post-closure program is also expected to minimize and mitigate
threats to and protect future human health a~d welfare and the environment.
RCRA closure requirements also specify that groundwater must be
monitored pursuant to 40 CFR 264 Subpart F (Section 264.117). The proposed
closure sped fies a groundwater moni tori ng program incompliance with
Subpart F. RCRA groundwater protection requirements establish a three-stage
program to detect, evaluate and, if necessary, correct groundwater
contamination. Initially, the uppe~ost aquifer and its characteristics must
be identified. The EPA Regional Administrator must then specify hazardous
constituents to be m~nitored for (264.93) and maximum concentration limits for
those constituents (264.94), as well as identify 'the point of compliance at
which the ground water monitoring standard applies and the monitoring must
conducted (264.95). The location and construction of the well monitoring
system must be in conpliance with 264.97. The detection and compliance
monitoring programs must be carried out pursuant to 264.98 and .99.
. The combined effect of upgrading runon controls and implementing wastewater
treatment of the,effluent from Waste Pond 5 is expected to have greater impact
on minimizing and mitigating threats to and protection of the environment
than Alternative 1 or 2. The volume and concentration of contaminants flowing
to the NFHR is expected to further decrease with the implementation of this
alternative.
Before this alternative could be implemented, a groundwater study, bio-
assessment and additional ~ampling need to be completed. Furthe~ore, a consensus
on the significance of seepage under the Pond 5 dike as a service of mercury loading
is unknown. Alternate 4 was not chosen due to the absence of information to justify
and imPlemJ?t this alternative. Alternative 3 was chosen as an int~r~~,alternative.
Costs
The projected costs were developed in accordance with EPA policy for
estimating costs within a reasonable range of the actual implementation costs.
Table 6 lists costs of the remedial' alternatives proposed.
-------
TABLE t - COSTS OF REMEDIAL ALTERNATIVES
PROPOSED FOR THE SALTVILLE SITE
Remedial alternative
No action
Upgrade runon control with
Total
capital
cost
($)..
N/A
50,052
Annual
O&M
costs
(i)
39,254
42,687
Present
worth
of annual
costs ($)
370,044
402,407
Total
. present
worth
(!)
370,044
452,459
ditches/berms/downchutes
Upgrade runon control with
ditches/benrs/dovnchutes and
treat Pond 5 outfall using
sodium aulfhydrate
precipitation
Upgrade runon control with 2,143,052
ditches/berms/downchutes and
treat Pond 5 outfall using
iron sulfide (sulfex)
precipitation
860,052 245,687 1,946,407 2,806,459
Upgrade runon control with
ditches/berms/downchutes and
treat Pond 5 outfall using
carbon filtration.
Treat Pond 5 outfall using
sodium sulfhydrate
precipitation
Treat Pond 5 outfall using
sulfide (sulfex)
precipitation
Treat Pond 5 outfall using
carbon filtration
Upgrade runon control with
ditches/berms/downchutes,
cap Pond 5 with synthetic
membrane liner, inrtall
ground water monitoring
system
219,687 1,750,407 3,894,459
• 840,052 182,687 1,469,407 2,309,459
810,000 242,254 1,914,044 2,724,044
2,093,000 216,254 1,718,044 3,812,044
790,000 . 179,254 1,437,044 2,227,044
7,645,035 163,663 1,542,883 9,187,918
-------
--
TABLE ~. (continued)
Remedial alternative
Total
capital
cost
(S)
Annual
O&M
. c 0.8 t S
($)
Present
worth
of annu4.1
costs (5)
Total
present
worth
($)
~pgrade runon ~ontrol with
ditches/berms/downchutes,
cap Pond 5 with synehetic
~embrane liner, install
~round water monitoring
system, treat outfall using
sodium sulfhydrate
precipi. tdtion
Up~r3de runon control with
dit~hes/bl::rms.'downchutes,
~~p Pond 5 with synthetic
membrane liner, install gwm
system, treat outfall using
lron sulfide (sulfex)
precipitation
Up~rade runon control with
dicches/berms/downchutes,
cap Pond 5 with ~ynthp.tic
,uembrane 1 iner, i!1s tall gvm
5ystt!m, trt!<1t outfall US1.!1g
carbon filtration
- 8,455,035
9,738,035
8,435,035
405,922
379,922
342,92l
3,456,927
3,260,927
2,979,927
tl,9tl,9b2
12,9'?9,Yb~
1 t .414 .9", :::
, .
j
j
-------
54
Table 7 presents a sensitivity analysis of total present worth. cost of
the cemenial alternatives and variations of the alternatives. 'Altern~tive
3 could ran~e between $2,300,000 to $3,900,000 depending upon treatment
technology chosen.
There are no costs presently developed for the groundwater study,
bioassessment or additional sampling and monitoring. EPA will be undertaking
these studies in the "near future. .
1\
./
-------
TABLE
1.
Va.ini....
SENSITIVITY ANALYSIS OF TOTAL PRESENT WORTH COST OF REMEDIAL ALTERNATIVES
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-------
RESroNSIVENESS SUMMARY
This community relations responsiveness summary is divided into the
following sections:
Section I
CNervlew. A diSOlssion of EPA' s preferred remedial
alternative and the public's expected response to this
alternative~ .
Section II
Background of Ccmnunity Involvement and Concerns. A discussion
of the history of cammunity interest and concerns raised
during remedial planning activities at the Saltville waste
Disposal site. .
Section III Surrrnary of Major Carments Received D.1ri~ the Public
Ccmnent Period and Agency Responses. A summary of canrrents
and responses categorized by topic.
I. OVERVIE.W
The selected alternative outlined in the ROD consists prUnarily
of uooradient stormwater control by construction of di tches, berms, and
swales and detoxification of contaminated material in an onsite pond.
This is essentially the same alternative which was proposed in September,
1986 but not finalized. It is an interUn solution, which will be followed
by additional. study and cleanup measures. Community interest thro\~hout
this project has been low and continues low. Most comments on the FS
were received from the States of Virginia and Tenessee (which is several
miles downstream of Saltville, Va.) and 01 in Corp.
Little public response is anticipated upon signature of this ROD.
However, the parties previously mentioned undoubtP.dly will provide input
at decision points throughout the project.
I I. eACKGROUND OF COMMUNITY nM>LVEMENT AND. CONCERNS
The height of community interest was reached with the closing of the
Qlin ~lant in 1971. Although contamination from the Olin facility resulted
in a ban on fishi~ in the North Fork of the Holston river many years ago,
r~sidents and former at1ployees rE!t1ained disinteeested. The only negative
. camrcent received by EPA Region III was the only written camrent received
during the camnent period. The .resident sLggested "the removal of contamination
to Mr. Olin's herre."
In 1978, a task force comprised of several state and federal agencies
was foemed to guide remedial actions at the site. The task foece has been
involved in most remedial plans and actions undertaken since that !time. ' " .
-------
-2-
The camrent perioo on the focused Feasibility StLdy began May,,21
and ended June 11. The comment period and the availability of the Feasibility
Study were announced in a press re1easesent to all Saltville a~ea
!redia, and in a quarter-page ad in the Saltville News Messenger - -
(attached to this sumnary) which appeared May 21. 'ibis ad offered a-
public meeting if needed. None was requested during the canment
period.- - -
III. Sunmary of major ccmnents received during the ccmnent period and
agency responses.
Risk Assessment
Canment: The Risk Assessment should have been revised to incorporate
data gathered through 1986.
Resp:>nse: The risk assessnent was canpleted without the 1986 data because
of the irrminent expiration of EPA' s contract with NUS Corp., the contractor
. which prepared the document. Past data provided enough information to -
complete this portion of the project, and additional studies are planned
which ~uld make use of all available data. .
Comment: The Risk Assessment did not include actual consumption survey
data and failed to consider ingestion of contaminated floodplain soils
as a potential pathway. Available literature suggests using from 1.0 g/
day to 5.0 g/day as a reasonable ingestion rate for Allowable Daily
Intake calculations.
-RP.sp:>nse: Additional st\.rlies are recanaended which may address these issues.
Canment: The predictive model which associates sediment concentrations
with fisheries contamination cannot be considered acceptable until
the continuous and variable loading of uncontaminated non~J.X>int source.
sedUnent is accomodated. In addition, a =~asonable program to ~ield
verify sediment/fish relationships at specific sample sites should
be defined including th~ use of available sedUnent/fish data.
Response: An updated report of the RA/FS will bt! issued based on the new
data generated in the sttrlies as ....ell as cut:'rent data from rtenbers of the
task force.
Feasibility Study
Comment: Remedial action should add=ess possible mercury seepage
unde = Pond 5.
Resp:>nse: The ground water stLdy described in this ROD will attempt to
addt"ess that issue.
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Comment: The ~easibility Study should have reconciled the discrepancy
be t....een EPA' s ~-sr.el'~ion that 92 percent of total nercury is methyl in
fom as oppOsed to Orfr\l~,J._~9nclusion that 50 percent of total mercury is
in rrethyl fOtH. . »
r- ..
Response: 1hi.& d'lscrepanc:y will be resolved at the conclusion of a
full bioassessnent.
.' .
Commeot'''~ ~A has not demonstrated . that tt\ere is a p:>tential groondwater
problan at the site. Therefore, a geohydrological study is unnecessary.
EPA has not demonstrated. any environmental effect on flora and fauna
of the North Fork Holston River area, therefore a study of whole body
concentrations is unnecessary.
. .
. Response: '!he Feasibility Sttrly states that. there is not enough infoanation
to determine if ground water contamination is present. There is no ground wa!
data available. 'therefore, a stooy will be done to determine whether
ground water is a potential route of exposure.
Comrrent: The water quality standard occasionally is exceeded within
.the mixing zone of the outfall trem pond five. It is not "consistently
exceeded" in the river as noted in the FS.
Response: The f~ct that water quality standards are exceeded in the river
is EPA's prnnary concern. The consistency of this problem will be better
documented in future studies.
ConInent: A party disagrees that the No Action alternative in the FS ¥IOuld
not sufficiently protect the environment. The No Action alternative includes
maintenance of the already implemented rEmedial rneasures, which are effective
in reduci~ nercury discharge to the river.
Response: EPA believes that mercury concf'!ntrations have not been t'educed
by remedial measures. This phenomenon appears to have been caused by
seasonal changes.
Comment: A party had several comments on implementation of EPA's
prefert'ed alternative.
- Runon control plans are Unpractical, considering the composition of
soil and waste material in the path of diversion ditches.
~ Plans to use ~~e waste pond as an equalization basin will ~nd liquid
behind the dikes and l~r their stahility.
- EPA's cost projections for bnplementation of the preferred alternative
probably at'e much too low. They do not take into account the difficulty
of ¥lOcking on an unstable surface (waste disposal areas.)
- EPA's proposal to utilize a wastewater treatment plant during the
cleanup may be Lmpractical.
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Res{X>nse: These issues will be thoroughly explare~t( WI6 - fiddrnssed ih the
design phase of the interim measure. . .
OtherCcrrments
CaT'IItEnt: Mile 52 of the Holston River should be identified as the
downstrean baJnd~ of investigations related to the Saltville site.
~s{X>nse: This recommendation will be followed in future studies.
. . . .
Comment: EPA projects the life of a synthetic membrane pro{X>sed under
the capping alternative as approximately 50 years. Such membranes have
been in use only 30 years. Olin Corp. projects the effective life of such
a membrane as less than 5 years. As such, they are not cost effective
in this instance.
Response: At this tUne, there is insufficient infocnation to evaluate
the validity of this comment.
. .
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