United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R03-88/030
September 1980
Superfund
Record of Decision
Chisman Creek, VA
-------
TECHNICAL REPORT DATA
/Pteast rtad Imtrucnoa* on iHt revtnt btfort committing)
1. REPORT NO.
EPA/ROD/R03-86/030
3. RECIPIENT s ACCESSION NO.
4. TITLE ANO SUBTITLE
SUPERFUND RECORD OP DECISION
Chisman Creek, VA
5. REPORT DATE
September 30. 1936
I. PERFORMING ORGANIZATION CODE
7. AUTHORIS)
8. PERFORMING ORGANIZATION «EPQ«T NQ
9. PERFORMING ORGANIZATION NAME ANO ADDRESS
10. PROGRAM ELEMENT NO.
1i. CON T n AC T/G H AN T NO.
12. SPONSORING AGENCY NAME ANO ADDRESS
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. TYPE Of REPORT ANO PERIOD COv£S£;
Final ROD Reoort
14. SPONSORING AGENCY COOE
800/00
IS. SUPPLEMENTARY NOTES
18. ABSTRACT
The Chisman Creek site, located in Southeastern York County, VA, is in a 520-acre
sub-watershed of the Chisman Creek coastal 3asin on the Virginia Peninsula. As a tidal
estuary, Chisman Creek flows easterly into Chesapeake Bay. Approximately 500 to 1,000
people live within one mile of the site in this primarily residential area. Chisman
Creek supports private and commercial marinas and numerous private docks, and is also a
popular fishing area. In 1957 and 1958, two units of the Virginia Power Yorktown Power
Generating Station began burning coal mixed with coke from a nearby petroleum refinery.
Fly ash was produced by these units until 1974. A private contractor, employed between
1957 and 1974 to haul the fly ash from the generating station, disposed of large
quantities of this incinerated coal by-product in four abandoned sand and gravel pits ir
the Chisman Creek watershed, approximately two miles south of the generating station.
No dust control measures were employed during the hauling, and uncontrolled erosin
caused fly ash to wash from the pits into Chisman Creek and its tributaries during heav.
rains. The remedial investigation conducted at the site found contaminants in the fly
ash, the sediments of Chisman Creek and its tributaries, the ground water within and
adjacent to the pits, and in surface water. The primary contaminants of concern
include: trace metals (nickel and vanadium), and inorganics.
(See attached sheet)
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS-OPEN ENDED TERMS
COSATi
Superfund Record of Decision
Chisman Creek, VA
Contaminated Media: gw, sw, soil
sediments, wetlands
Key contaminants: trace metals (nickel
and vanadium), inorganics
IS. DISTRIBUTION STATEMENT
19. SECURITY CLASS > Hut Rtporti
None
21. NO. OP PAGES
46
20. SECURITY CLASS ,Thit pagtl
22. PRICE
POT* 2230-1 («•». 4-77) PRCVIOUS COITION is OBSOLCTC
-------
EPA/ROD/R03-86/030
Chisman Creek, VA
16. ABSTRACT (continued)
The selected remedial action includes: capping Areas A and B with a soil
layer overlaid with topsoil and vegetative growth; capping Area C with a
low-permeability compacted soil layer overlaid with topsoil and vegetative
growth; installation of a subsurface drain on the west, south, and east
sides of Area C to lower the water table below the bottom of the fly ash;
transportation of ground water drainage from Area C to an onsite treatment
plant; extension of the Newport News and the Allen Mill Road waterlines to
affected homes; implementation of deed restrictions or other controls to
prohibit excavation of soil and restrict onsite building and ground water
use. The estimated capital cost for this remedy is $14,119,000 with O&M
costs for year one of $506,000 and $64,000 for years 2-30.
-------
RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION-
Sice: Chisman Creek Sita, Grafton, York County, Virginia
Documents Reviewed:
I am basing ray decision principally on the following documents
describing the analysis of cost effectiveness and feasibility of remedial
alternatives for the Chisman Creek Site. Also, meetings to discuss these
remedial alternatives have been conducted with the State and the general
public. I have been briefed by my staff on the documents and the meetings
and they form the principal basis for my decision.
- Remedial Investigation Report, Volumes I and II, Chisman Creek
Superfund Site, York County, Virginia, November 22, 1985, prepared
by CH2M Hill
- Public Health and Environmental Evaluation, Chisman Creek Superfund
Site, York County, Virginia, August 1986, prepared by CH2M Hill
- Feasibility Study Report, Chisman Creek Superfund Site, York
County, Virginia, August 1986, prepared by CH2M Hill
- Staff Summaries and Recommendations
- Public Comments and Responsiveness Summary
Description of the Selected Remedy:
1. Areas A and B - These fly ash pits will be capped with a soil layer
overlaid with topsoil and vegetative growth to prevent direct contact
with the fly ash and to minimize erosion of the fly ash.
2. Area C - This fly ash pit will be capped with a low-permeability cover
overpaid with topsoil and vegetative growth. A subsurface drain will
be installed on the west, south, and east sides of the fly ash pit in
order to lower the water table below the bottom of the fly ash.
Contaminated ground water collected from the fly ash during the initial
drawdown period will be conveyed to an onsite treatment plant. Once
the ground water being collected through the drain is shown to meet
National Pollutant Discharge Elimination System (NPDES) limits, the
treatment will cease.
3. Alternate Water Supply - The homes along Wolf Trap Road will be connected
to the existing Newport News waterline and the homes along Aliens Mill
Road will be served by extending the existing waterline to Aliens Mill
Road. During the design of the remedial alternatives, a survey of the
-------
existing water supplies will be conducted. The survey will determine the
the number of homeowners currently using the Tabb or Yorktown Formations
for drinking water and the corresponding number of connections to the
alternate water supply lines.
4. Land Use Controls - EPA will attempt to obtain deed restrictions or
other controls on the use of the fly ash pits and immediately adjacent
areas. These restrictions should prohibit excavation of soil and
restrict building onsite. These controls should also include restrictions
on ground water use in the pits and down gradient of the fly ash pits.
5. Monitoring - Post-closure monitoring program for the ground water and
surface water will be designed and implemented.
Operation and Maintenance
The State of Virginia will perform post closure operation and
maintenance of the site.
Continuing Action
The U.S. Fish and Wildlife Service is preparing a study for EPA on Che
environmental impacts of the site on the streams and ponds adjacent to the
flyash pics. Once the U.S. Fish and Wildlife Service concludes its scudy,
EPA will determine the need for additional remedial measures for any ponds
or streams affected by the site as a separate operable unic under Section
300.68(c) of Che National Oil and Hazardous Substances Contingency Plan (NCP),
40 CFR §300.68(c).
Declarations
Consistent with the Comprehensive Environmental Response and Compensation
and Liability Act of 1980 (CERCLA) 42 U.S.C. §9601-9657 and Che NCP, I
have determined that the remedial acCion described above, together with
proper operation and maintenance, constitute a cost-effective remedy which
mitigates and minimized damage to public health, welfare, and Che environment.
The remedial action minimizes or eliminates che Che chreac of further
contamination Co Che groundwater and the environment. The State of Virginia
has been consulted and agrees with che approved remedy. These activities
will be considered che approved action and eligible for Trusc Fund monies.
I have determined chat che action being taken is appropriate when balanced
against che availability of Trusc Fund monies for use at other sices.
n
James M.
Regional Admincstracor
-------
SUMMARY OF REMEDIAL ALTERNATIVES SELECTION
CHISMAN CREEK SUPERFUND SITE
Site Location
The Chianan Creek Superfund site is located in Southeastern York County,
Virginia, in a 520-acre sub-watershed of the Chisman Creek Coastal Basin on
the Virginia Peninsula (Figure 1). Chianan Creek is a tributary to Chesapeake
Bay. The site consists of four abandoned sand and gravel pits that were
filled with fly ash from the Virginia Power, (formerly Virginia Electric and
Power Company), Yorktcwn Power Generating Station (Figure 2).
The four fly ash disposal pits are located adjacent to Wolftrap Road
(State Route 630), approximately 0.7 miles northeast of the intersection of
Route 630 and tj.S. Route 17 (figure 1). The southerrmost pit, Area A, is
approximately 13.5 acres in area and is bordered on the west by the former
York County municipal landfill and on the east by Route 630. Area B,
approximately 4.5 acres, is 700 feet north of Area A and is bordered on the
east and west by intermittent streams. Area C, approximately 12.9 acres,
is 500 feet northeast of Area B, and is bordered by Route 630 to the west and
by .Chisman Creek to the northeast. Area D, approximately 5 acres, is 150
feet northwest of Area C. Parts of Areas A and C are elevated between 5 and
20 feet above the surrounding land. The relief of Areas B and D is similar
to that of the surrounding land.
Surface Hydrology
The predominant surface hydrologic feature of the area is Chianan Creek,
which is located directly east of the fly ash pits. Chisman Creek is a
tidal estuary 3.75 miles long which flows easterly into Chesapeake Bay. The
Creek is approximately 0.5 miles wide at its mouth, where the average depth
is 12 feet. The mean range of the tide in the creek is approximately 2.5
feet.
Surface drainage of the area around the fly ash pits occurs through a
wetlands and a number of small, unnamed tributaries to Chisman Creek. Natural
drainage throughout the area has been altered by man-made ponds which resulted
from the excavation of sand and gravel fron the Tabb Formation. A number of
these ponds also drain into the tributaries of the creek (Figure 2).
Hydrogeology
The four fly ash disposal pits are situated on the Hornsbyville Flat, a
1/2 mile wide plateau characteristically 25 to 30 feet above mean sea level.
-------
YORKTOWN POWER
GENERATING STATION
SITE LOCATION
CMISMAN came PS
-------
e 20 ooo
N I'J oui
N i; (
Figure 2
STUDY AREA
CMISMAN CHEtK »S /»'V'l'/Jf
.
-------
The Chisman Creek sice and surrounding area are underlaid by cwo geologic
rortnacions, the shallow Tabb and deeper Yorktown Formations (Figure 3). The
Lace Pleistocene Tabb Formation is composed primarily of medium "sand wich
sone gr.ivel or cine siLcy clayey sand, and is of moderace Co high permeabilicy.
Locally, che thickness of the Tabb is as much as 20 c'eec. In some areas the
Tabb has been completely excavated or removed by natural erosion.
The late Miocene/early Pleistocene Yorktown Formation underlies the Tabb
Formation at the site. The Yorktown consists primarily of greenish-gray,
silty sand with whole and broken calcareous fossils (shells) interspersed or
heavily bedded throughout; it is of relatively low permeability. The thickness
of the Yorktown at the sice is unknown, but it is estimated to be 100 to
150 feet.
The regional pattern of ground water flow is from major recharge zones
in che highlands west of the study area, eastward to discharge zones in and
along Chisman Creek. In detail, however, ground water flow patterns in che
study area are much more complex, shaped by details of surface topography, by
local recharge within the study area, by the difference in conductivity
between the Tabb and Yorkcown Formations, and by the topography of the surface
of the Yorktown.
In general, local flow directions in the Tabb are toward the ponds and
stream channels tributary to Chisman Creek. The direction and estimated
velocity of ground water are shown on Figure 4.
Vertical movement of ground water generally is downward from the Tabb
into the Yorktown, but at a very low velocity (less than 10~7 feet per second
or less than 3 feet per year) over most of the site. However, relatively
strong upward flows occur along Chisman Creek and around the other surface
water bodies. The Yorktovn Formation presents a significant geochemical
boundary by virtue of its high shell (calcium carbonate) content, which causes
pore waters to have very high pHs.
Area Land Use
Approximately 500 to 1,000 people live within 1 mile of the Chisman
Creek site.^_Land use in che immediate vicinity of the site is mainly for
single family residences. Extensive residential construction was underway
to the south of Area A at the time of the Remedial Investigation (RI).
Chisman Creek supports private and commercial marinas and numerous private
docks, and is a popular fishing area for both private and comaercial fishermen.
Ponds in the area are reportedly used for recreation as well.
Municipal water service has been extended to most of the residences
adjacent to the flyash pits. However, 46 residential wells in the vicinity
-------
^*^ *•*•*• * •***• """*****
- * v» *•*•** * • * • •
-20
SCALE
HORIZONTAL : l"» 300*
VERTICAL: l" » 10'
SOURCE: CHl.M HILL.ORAFT REMEDIAL
INVESTIGATION REPORT (NOV., 1983)
TYPICAL
GEOLOGIC CROSS SECTION
C.C.JOHNSON a ASSOCIATES,INC.
-------
LEGEND
Contour lnl*n«l'
4F«M.
ttov«i'o«. H«lorr*d
10 MMM tut Livd.
Flo« Velocity V
(Spoclf le DMdwrfi I
in Fi /D«y)
A:
• : 2.10 ;
ci a«io
C2 3.10 '
C3 3MIO
t
\\
«'
.) :•'•
.„•***
INOT|:C» "•
-------
of the site were being used for potable water supply at the time of che
RI. Most of these wells are believed to be completed in or below che Yorkcown
Formation, but at least two are completed in che Tabb (depths less than 30
feet). Approximately 20 other wells in the area are used solely for purposes
other than human consumption (e.g., watering, gardens and lawns.)
Site. History
In 1957 and 1958, two units of the Virginia Power Yorktown Power
Generating Station began burning coal mixed with coke from a nearby petroleum
refinery. Fly ash was produced from these units until 1974, when Virginia
Power converted them to burn fuel oil.
Between 1957 and L974, Virginia Power employed a private contractor to
haul away the fly ash from the generating station. The contractor disposed
large quantities of the fly ash in four abandoned sand and gravel pits in
the Chlsman Creek watershed, approximately two miles south of the generating
station.
Homeowners in the vicinity of the sice reported that the fly ash was
transported to the pits in open trucks. No dust control measures were used,
and fly ash apparently blew from the trucks and the pits. Little, if any,
attempt was made to control erosion, and during heavy rains fly ash apparently
washed from the pits into Chisman Creek and its tributaries.
Area D appears to have been partially filled wich fly ash within
approximately the same time period as the other three pits. However, the
owner of Area D reported that all of the fly ash was excavated from Area D
and deposited in Area C sometime between 1971 and 1973. Area D was reportedly
then refilled with construction rubble from public utility construction
occurring along Wolftrap Road at that time. The RI confirmed the removal of
flyash as the drilling samples showed only traces of flyash.
As encountered in borings at the site, the fly ash is typically a dark
gray silt or fine sand, with occasional gravel or pebble-sized fragments.
Fly ash in Areas A and .C appears to be covered with a patchy deposit of sandy
fill up to_two feet thick.
In 1980, a domestic well west of Area C was reported to have discolored
water. In 1980 and 1981, the State Board of Health (SBH) and the State Water
Control Board (SWCB) sampled ground water from residential wells in the
vicinity of the fly ash pits to determine if contaminants were present In
elevated concentrations. Subsequent studies to determine the nature and
extent of contamination included investigations by the SWCB and Virginia
Institute of Marine Science (VIMS). Both of these studies found ground water
and surface water contamination in and near the fly ash areas. As a result
-------
-8-
of data gathered and conclusions drawn by these studies, che site was included
on che National Priorities List (NPL) in 1983.
Remedial Investigation Findings
The RI was conducted from 1984 to 1985 and a report was issued on
November 22, L985. The RI found that contaminants are found in the fly ash
itself, in the sediments of Chisman Creek and its tributaries, in ground
waters within and adjacent to the pits, and in pond and stream waters tributary
to Chisman Creek. Nickel and vanadium are the most ubiquitous and abundant
of the trace metal contaminants; arsenic, beryllium, chromium, copper,
molybdenum, and selenium are also present at elevated concentrations in some
parts of the study area. Sulfate and total dissolved solids (IDS), which
occur naturally at relatively high concentrations in the Chisman Creek estuary,
are also elevated in ground waters and tributary waters contaminated by the
fly ash. No organic contaminants attributable to the fly ash were found
during the RI. Samples of fly ash taken directly from the pits did not
contain hazardous concentrations of trace metals, as determined by the EP
Toxicity test. The RI concluded that this localized contamination is caused
by the tly ash pits.
For soils and sediments, highest levels of contamination are found in
samples from the fly ash disposal pits, which have concentrations of vanadium,
nickel, arsenic, beryllium, copper, and selenium between about 10 and 100
times background. Concentrations of vanadium and nickel are comparably high
(up to more than 100 times the background levels of 10 to 15 ppm) in sediments
from two ponds directly north of Areas A and B. Sediments from some parts
of the tributary stream channels show concentrations of vanadium and nickel
up to about 50 times background. Sediments from the adjacent part of the
Chisman Creek estuary are contaminated with vanadium at concentrations above
approximately 100 ppm; sediments from much of the rest of the estuary have
relatively low levels of vanadium contamination.
For shallow ground waters, highest levels of contamination are again
found within and immediately beneath the fly ash pits, where concentrations
of TDS and sulfate are approximately 10 and 100 times background levels,
respectively. Trace metals showing highest concentrations above background
are vanadium and nickel (up to about 1000 times background); arsenic, beryllium,
chromium, copper, molybdenum, and selenium show concentrations up to more
than ten tines background.
Filtered samples of contaminated shallow ground waters in the Tabb
Formation downgradient of the fly ash pics also have high levels of TDS and
sulfate, in excess of the Secondary Maximum Contaminant Levels (SMCL) of 500
and 250 ppm, respectively. (SMCLs are Federal aesthetic standards and have
no regulatory weight.) Elevated molybdenum and vanadium are found in ground
waters downgradient of all pics but not at levels that indicate human health
problems. Elevated nickel is found in ground waters downgradient of Area C.
-------
-9--
Th e ground water samples downgradienc from Area A and B do not have elevated
levels of nickel. None of the samples taken from residential wells in the
area was found to have constituents in excess of primary and secondary MCLs.
(Primary MCLs are Federal guidelines that establish human health standards.)"1
For surface waters, highest levels of contamination are found in two ponds
north of Areas A and B, where concentrations of TDS and sulfate are approximately
five and twenty times background levels, respectively. Tributary channels
downstream of these pits also show elevated TDS and sulfate. Concentrations
of sulfate and TDS in these tributary waters exceed the SMCLs.
Concentrations of vanadium are high (up to more than 10 times background)
in the pond north of Area A and in the stream channel adjacent to Area C;
vanadium is slightly elevated in the pond north or Area B. Nickel is present
at slightly elevated levels (approximately two times detection limit) in the
stream channel adjacent to Area C, and molybdenum is found at similar levels
in the two ponds. Surface waters in the study area are otherwise free of
detectable contamination.
Monitoring wells in the upper part of the Yorktown have shown no
contaminants that exceed EPA Drinking Water Standards or Ambient Water Quality
Criteria. Three deeper monitoring wells were recently installed to assess
that part of the Yorktown that is thought to be pumped for residential
supplies. The ground water samples from these wells also did not exceed EPA
Drinking Water Standards or Ambient Water Quality Criteria.
Contaminant migration pathways at the site include erosion, surface
water transport and ground water transport, with erosion judged to be the
most significant historically. Contaminated sediments are widespread throughout
the study area in depositional environments. Surface water transports small
quantities of dissolved contaminants through the ponds and tributary channels
into the Chisman Creek estuary.
Public Health and Environmental Assessment Findings
Potential public health risks from media assessed during the RI were
found to be as follows:
0 Human consumption of ground water at contaminant concentrations found
in ClMMnonitoriag wells within Che flyash pits would exceed guidance levels
for specific noncarcinogens found at the site (See Tables 5-8 and 5-9 of the
PHEE and EPA sample results from April 1986). A cancer risk (10~2 to ICT3)
is also associated with human consumption if arsenic is considered a
carcinogen. Properly filtered ground water samples outside the flyash
pics revealed no contaminants at levels exceeding EPA guidelines with
the exception of Nickel, which was found in monitoring wells downgradient
of Area C. The proximity of residential wells to the pits and the on-going
and potential future migration of contaminants from the pits presents a
public risk from contaminated groundwater.
0 Based on field observations of children and adults frequenting the
site, exposure to fly ash through ingestion presents a health concern.
-------
-10-
As discussed in che PHEE, persons ingesting flyash at quantities (0.1
g/day) over a lifetime would approach maximum recommended intakes, and
at higher quantities (1.0 g/day) actually exceed recommended intakes of
noncarcinogens. A cancer risk is associated with the recreational
setting for both children and adults.
The impacts of the site on off-site surface waters are being further
investigated by the U.S. Fish and Wildlife Service and will be evaluated in
another Record of Decision as a separate operable unit.
Remedial Action Objectives
As specified in the National Oil and Hazardous Substances Contingency Plan
(NCP), "the appropriate extent of remedy shall be determined by the lead
agency's selection of a cost-effective remedial alternative that effectively
mitigates and minimizes threats to and provides adequate protection of public
health and welfare and the environment." NCP §300.68(i). Generally, "this
will require selection of a remedy that attains or exceeds applicable or
relevant and appropriate Federal public health and environmental requirements
that have been identified for the specific site." Id. The remedial alternative
for the Chtsman Creek site must be consistent with the NCP.
The remedial alternatives discussed in this document address the
identified, existing public health and environmental hazards associated with
actual or threatened releases of hazardous substances from the site.
Remedial action objectives are presented below.
1. Direct Contact: Prevent human contact with or consumption of fly
ash or fly ash-contaminated soils.
2. Ingestion of Contaminated Water: Prevent human consumption of
water contaminated by fly ash in excess of relevant human health
standards and criteria.
3. "Wetlands Protection; Minimize disruption or destruction of
existing wetlands that might result from the implementation of
remedial actions at the site.
4. Water Protection; Prevent further degradation of ground water
quality to levels that could jeopardize human health or the
environment.
5. Water Restoration; Restore the quality of ground water in the Tabb
Formation. Surface waters may incidentally be benefitted by
measures taken in this Record of Decision.
-------
-11-
Identificacion and Evaluation of Alternatives
Alternatives to meet the remedial action objectives are classified as
source control or management of migration remedies (See 40 CFR §300.68(c)).
Source control alternatives are directed at controlling the source of con-
tamination. These alternatives will address the problems associated with
the fly ash pits. Other areas besides the fly ash pits could be considered
sources of contamination if enough contaminated material has migrated to
these areas, however, this does not appear to be the case at the Chisman
Creek site. The source control measures will seek to completely remove,
stabilize and/or contain the hazardous substances. The impacts of the
site on off-site surface waters are being further investigated by the
U.S. Fish and Wildlife Service and will be evaluated in another Record
of Decision as a separate operable unit.
An initial screening of the potential remedial technologies for the
flyash areas identified in the Feasibility Study (FS) was conducted pursuant
to §300.68(g) of the NCP to narrow the list of potential remedial actions
for detailed evaluation. The remedial technologies eliminated during initial
screening are shown on Table I.
Alternatives remaining after the initial screening were analyzed on the
basis of the requirements of §300.68(h) of the NCP. A comparision of these
alternatives, as presented in the FS, is on Table 2 and 3, and the costs are
on Table 4.
I. No action with monitoring.
2. Access restrictions (land use controls), alternative water supplies,
monitoring programs, soil cap topped with a vegetative layer.
3. Access restrictions (land use controls), alternative water supplies,
monitoring programs, low-permeability caps, slurry walls, interior
drains for ground water control, and onsite treatment of water
withdrawn from the drains for Areas A, B, and C.
4. Access restrictions (land use controls), alternative water supplies,
monitoring programs, low-permeability cap, perimeter drains to dewater
Che flyash, and onsite treatment (during dewatering only) of water
withdrawn from the drains for Area C. This alternative applies only
to Area C. This alternative, considered as a whole, was infeasible
at Areas A and B and, therefore, another of the retained alternatives
would be chosen for these areas in conjunction with this alternative
for Area C for the site remedial alternative.
5. Alternative water supplies and excavation and offsite disposal of
flyash.
6. Access restrictions (land use controls), alternative water supplies,
monitoring programs and in-place stabilization/solidification
of the flyash.
-------
INAPPLICABLE TECHNOLOGIES
General Response Action
Containment
Techno locv/Technolocy Option
Capping vita Asphalt,
Concrete
Vertical Barriers:
Grout Curtain
Sheet Piling
vibrating Beaa
Horizontal Barriers:
Block Displacement
Gradient Control:
Extraction Hells
Comments
Susceptible to cracking from
settlement, shrinkage, frost
beave (not self-healing)
Not appropriate for site con-
ditions; difficult to assure
integrity
Interlocks difficult to seal;
not water-tight
Difficult to assure integrity
Difficult to assure continuity;
not compatible vita sit*
conditions
Mot as efficient or cost-effective
as drains
Hater Treataent
Biological Processes
Physical Processes:
Activated Carbon
Ion Exchange
Reverse Osmosis
Thermal Processes
Not applicable for the removal
of inorganic constituents
High doses/cost required com-
pared to chemical precipitation
Inefficient in comparison to
optimum technologies
Not applicable for many waste -
streaa constituents, costly
Not applicable to inorganic
constituents
Hater Discharge
Onsite: Aquifer
Reinjection
Offsite: POTH
Industrial HWTP
No advantage In comparison to
direct surface water discharge,
yet more costly
Not acceptable to York River HWTP;
no advantage for the discharge
of treated wastevater
Not cost effective for flow
rates anticipated at the site
Soll/Flyash Onsite
Treataent
Stabilization/Solidification:
Excavate/Mix/Replace
In-Sltu-Injectlon
(Permix™ PT-S
Stabilization System)
Technical implementation
constraints due to blob water
tablet hign cost
Relative Impermeability of flyasb
makes this technology infeasible;
difficult to assure complete
mixing} primarily applicable to
sludges and semi-solids
-------
LS TECHNC10GISS
(Conti.-.uei)
General Respons* Action Technology/Technology Option
Soll/Flyash Disposal Or.site RC3A Landfill
Connents
Site is unsuitable for construc-
tion of a RCRA landfill due to
high water table, floodplain
location, and-^constrlcted area
-------
Tul.l.-
CO1PUUSUI Of ALTDolATlVtS
*ll*ra*ll»« 1
•edbUctl
evaluation allematle* 1 Mlernellve J
Crlterle •* kctia* Soil Cap. Ill
r rrinillll MIOM COO* Mead I Soil capping end land
potential Id* eUract ' uee reetrlcllona
contact ellk llfan* ellocllveli i educe
ami UH»»|a». *i CM- «k* potential lor
laalaalad njai.Hi ill I direct rooted ellk
Ike potential fat llveok. Alternate
OOMIMO) aoManlaeat ealer eupplf IHrSI
*l«iatl*> l> ant reduce* Ike potent lei
of centenlneled "
fioaadealar. Tka
conlaaleaal aouic.
at II oat be coa-
lalaed. ofOlla
algrallo* elll
continue.
evllatalllf Hot Aopllcable Soil capping and land
u»e restriction* kae*
proven pertoraaaco.
Loag-lera afl*ctlv*
neee U depeaaa.1 oa
Uriel lupoctloa aad
•alateaanc*.
Lav-Pern Cap.
SUltf Hall,
Graundeator Control/
Treala*al« 111
C«w|«t.,||«rt|..ir
i«Mk*cm« tit* potcntl*!
lot dlroct ctwlftct
*1U> f ftyutl OAd
roOtscc.) roctiorgo of
e*«t«( IfOB IBO
OVrlOCO t«, lee* pill.
TO OtUUrO
•f foct Ivov-rca* lb*»
cop «u»t b«
•Olol*llMt«.l.
col loci ion/
1 r**t •»•!
•ltd olleraolo ••i«rr
•upptl f«4kK»> lit*
po4««li.»| foi •• — r~
COM*.*p«IO« 0.
9lounO..*t*( . 01 1 • 1 1 o
eDnio*l*ot|on Bill bo
lovolo U JO-iO r**r«
ooc« cootttlnaool !•
l» ploc*. Saoll
tt-nr* ol Mtor will
Itovo lo »• Ii*ott4
Cor on 1-vWllQlt*
pot tod of tttw.
TiooiBMit *y»tom vIM
bo oMoctl** In
•ootlof voloc •jbtolliy
•tw.4or.U U propoilr
Cop* bov*i provo«
potlo.nii.iCi. H-tlll-
loyor cop «.»•*>•
ooVlllOaMl oofoty
focior. rvopor
OOlolOO^kO* MSI bO
porloraM iv*6>IUilo-
lf lo lo««tro ioAtj-
l«ra •l(«ctt««aotw.
Slurry vollti hovo o
provo* porlortMoc*.
Or t.1 00 MM.-4 DC «Mp
•MWft. !• MlMolO MO
tHodMTOl.* ol flfOnH.1-
volor l*to to*
loiklOMi AKlng liooo
of loo votor lofcU.
OroiM-kiOlor iiooi..«nl
oioio* *t*M provon
porfon.Mboo.
•ovttroo pilot oiMl»,
rotjolor oaollorlof.
0.1.1 (rtlooil opoiollo«
parooMMl.
AM*in..tl**> «
Uw-fv.o. C«o,
(.lv.dl.ml Tonliol/
TiVvUMnt. UI
S*t* •liofo.iilv* 1 tor
rOWlO^ eUMv, JU.S
dloc^stloa.
Mill I**** llM
polontl.il lof *-]—•-
CuaI-vo>«l. AM
flr--»h oicovotloo on*!
dlOpOMl OlflltO Mill
gcootlf ro4-tco too
.ung-ttMM polootlol
lor dlioct conioci
•Itb llyooo or cuo-
• ••IOAto.1 9(oun4*
••lor. Of fill*
lAol loo •!!! b« n«*f
bocittirtMiMd !•••!• !•
20- 10 you* onco
on*llo oooloolnoiloo
!• (•oxraod.
SlM/d-lcr* 9fMUM)*
••I** liooloonl will
b« ooc«ift«ry •oil*
dw*«l*iloq •icovo-
11 oo. Sn All. 1 for
91(M.nO**t«t tlVfttBODt
dlftCUMloO.
No OUI IB i*quli«d
upa« coopUtiao of
(bo B.A. IMllottllltr
lo hloH.
A.l«ra«l !•• *.
SloMIUtil I.M./
So Hd II lft.1 l*>n. UI
C.l*ct|. «!>.», u( :,/^
I* *.np(ot;«n. hriith-
e>C«l« !«•(• UIU
d«l«miW I!.*} dll«.l*V
oL*l« !«••. of n*«i-
looloot l.wnntlii.-
ol ou««i /•!• 104 iini|»
!• HnpfOVOAf p) Itil
!••!• OOilt* Ml I) |.«
ooatatMry lo dftn-
OlOO It p»lf.lI»eUM*
9MU COA t* Ml.
Soil ctvp •iH.id
t«K|.|ll« |b»(WI|u.»
OM) oolnioooiMv
pro«ro* lo oiuuic
loto^riif . Ki luiii-
OOCO Of ||M pfO(<.ikOd
S/S atyato.. tkol Mil
dOOOOtt l*t«K>. tf
-------
Technical
tvaluetlon AltanuUlve 1 Alternative i
Criteria •» Artlun Soil Cap, 111
lapUMtnklllti H»t A»»Uca*le Soil cappluv Is
easily Implemented
•life conventional
n*l hods. The leoal
bast* for necessary
land MM restrictions
Safety Mot Applicable Installation ol cap
requires convent lone 1
•It* safety proced-
ures. Potential
•sposur* to llyash Is
•Uloel.
-.ul-l.
IcuUlnuedl
Alternative 1
Luv-Pvfo f*i».
Stuiry veil.
Giounduatei Control/
Treatment, 141
Tap can be const rurt •
•d with convent lonal
equipment . last a 1 la •
tloo of cap elll
require strict
Quality control.
Construction ol cap
rural 1 conveyeac*
structures nay Impact
sfr'ni^'and*^.
Slurry veil and drain
syslo* can be Imple-
mented wltto conven-
tional equipment.
Steep slopes end
dlyfllno, in tlyash add
estr* dllllculty to
standard procedures.
Construction of treat-
•wnl syslas) is
routine, niot study
Inslallallon ul cap
requires standard
all* safety protvd-
ures.
Salety during con-
struction of aluiry
vail and ataln ts ol
concern due lo dliact
vMpusui* to llyash.
Sbort -tern around*
water attraction and
treala^nt systast
Ullure Is not
especled to Utroduc*
substantial health
AMental l»» 4
l.» Wra. (sp.
Trealneol t 141
We Alternative 1 lur
raof to^ snd AM5
discussion.
bialn system can be
fimsliuctcd mil) con*
vetittoiial «Mult««rit .
fiOBlaHly ul load lu
«e»t side ol llyssb
ptt nates Isvleajenta-
tloa dllll>ull.
See Alternative 1 lor
casing and treatment
discussion.
Salety during con-
struction of the
drain system Is ot
concera due to
exposure to coatan-
1 naiad* groundvater
•rut deep excavation.
Alleiltallv* ) Alici4t*ilve 6
taiawat loo, blabltii*! !<«/
Ollsiie Dispose^ AHS Suli.Ui t. *i iitn. 11.1
bnavallon. tiaiis- Avsllal-illty ol'
port, and disposal *\»4«< /eUlt»* tioa
can be lapleawnted «.uuld po>* •
elth conventional 1 lalul . Har
net bods. Sleep ieg-uli« nevrtal years
•lopes naae e«ca«a- to lavlcawoi .
lion neat ptt edo*a
difficult. Hsy
require several yeara
to lapleetrnt.
Salety durlnqcoti- HuieniisI i|*iieialion
Stnirtlon Is a ul l>>*»h dustn rtuiln^
costotrn due to dlrrct to* atiin^ process. •
esposure to flyasb.
Transport of llya>n
over public roads is
• cancer*. Possible
dust ovneieilon or
ace Ideal a 1 spills.
-------
KkJLIC MM.n, k*Xr*M. «*> OKI
•u. tmcn or uttMtrins
lM I
Action
Ali*ra*ti«*
••II Co»
i t I
MtonMtlM I
U. tarn. C**>,
•Urri Mil
MUratllra 4
MUraallw 1
On
Otfuu
I t I
rwkiic kooUk «*4 Mllfft to**
LOM-UIV lo»oct*
fly*M aatoatl*! foe kM*a for MM» oMt*ct 11*1 for kaa*a
OMlMlMl*4 OMlaCt (Ilk II|OM. Oltk MfOOfc. Ul CMloCt Oltk III!
0>o4 r*Mflctla*» coalnl* ri>n i loo 141 OMlrolo •* i
r*4*c* *«p*Ml>> **4 0at«*ll*l foe l*a**- Mlora*llta I. trvi*jM*t*r ol tko f*4*o4lol for'
*llora*lo MIOT HM of OMtMlaoto4 tut i mi* »rmollM ill* k| IMM!** 11 MIAMI io loll.
loatlM of coaiM- MlorcoMM of |M4 of I*a4 M* r**utc- fnnallM of
lMlo4 froM4Mior. MO rMUIctloM M< tioaa M4 *IOMI c*« offtll* i
IMIIM U Mt CM-
I«|M4. MMlfM *M**IIOl I
Mlara*MM of Iw4 u ynaarli >*|M*. orap*fi| >*|M*. 4li«o**l ftciui-.
ooo rMtrlctlM* M*
ndbctlw U
CoMln>cila*-MUto4 lapoct*
•I 4l«rff ooll o*4 Soo Allomotlvo I fotonllol lot orpo- Polooll*
i Io 4r*l* coaalnclloa our* of cuMlractlM for OM>
i 4liort Mruro Io fltook. Io MlrolM4 4uol.
yroloclloa *kMl4 Io fli**k. rioiwr M|M *io • rxnini cMOin Io Mrt*i*.
aill«al* aalmtlol kMltk M* **lol| I* Mitoro oa4 to l*na*M4 li.llic
alllftlo wloMlal
rln. Tlaftlc **4 Irofflc 0*4 cua-
OMoinctlM nIMM oininio* rout*4
MlM 0*4 MM MlM M4 MOt
•ffoct annoJrtlaa,
(Mlaral* r**!4tala.
•L
foe «*po-
fMloa of •«» ol lortoolilol
roalMlnoIlM Ik IM M4 o«Mllc llfo t*
0»lfOMMl. flMOk l> rtMD»4.
DM«llo4 «.«lyollOM *IUc«4 4i«lMM (I
of tkvto lopoct* kra kit* m»t rt4wk
Iko nkltrl of MIIM4 kMlIM M
IMIMI My4f. k4|on*4
MfOO
ftMMVlor raMff
Mf Olltf MlUllf
of o4|oCMt oMMrr
kllM
of lofioMilol
ooxllc III* lo
fllMk lo ri»»c«4.
ouowro SM*|O I
f>Monr* of lorroo- SOM M
•f OM|*B|-
a*t*4 aroMOMlor
•r* alllf*lo4 n*r
I la*. Olrocl *>r-
foo* o*l*r 4loc*jor9*
croala4. fkl* MI
•I lor *oa/or '
lie M»lr
lie* of Ik*
4IOCMIO*. I.O.,
•Ic. *ii*r*4
•rolooo* M| roawo
Ml 10*4 kMlIM Ol
•4 la
•l»
IrukMlor rMofl
•of ollor Mllolli
of o4|*r*«| oMvorv,
ollorllM '
Iriol *+ OOMIIC *>c*pi
II |0 lo II|*M I* 41
ollal**lo« M Ik*
• II*.
ftllomot 1*0 I.
M •HffOCO
lor.
• Although lencins) of the site woa includad aa part ol Altarnatinw >. 3, 4 and
«> in the Feasibility Study, Iron winch tlua Tabla •• «»c«rptad, ta dacidod
the U-m-iiKj Iron each of theae altamativaa tacaui r*at
use MI!.' IK i-onaideied oa an appropriate accaaa raatii.
to
and
Tins ««Klilic,,riaii ia
rictiuna
<«"• •*»••• '•"' M>n.rial!if »fl«et
nl
-------
| Altan.*ll»« 1
t**.i*UM C«t»f»f| M> ATlln*i
I'ni.if i
|uMtlou*4|
Luv Fwt». Cap.
Sluiif Mall
Ml*nv*Al«* 2 Gioutw>Htt1«f
Soil CH> Conuol/Ti*ftl*rot.
141 til
All«in«( !«• 4
tov f*f«. Iftii. All«nt«l !»• 1 Allrn.aU** ft
i>l*dl#ut Cuntiui t-»i »<*•! Ion/ SI *1>1 lt.«t ion/
TlCAlarot Ull»ll« Dlft^uaal !>«lll]|| 1. at IUA
1 i 1 AHS | i |
''--Tiiln«-||-T r-t"rt laini "»"• TMVOIIII IOM of Coulnicllau •ctlil- SM *lt«in«ll«« i Ui*.*< Ion » 1 1,1 - T«^»i>ir loi. «l
• IU1IU (rca •!•*< !!•• Ml ««rct !!•• M| •li«| •lldlllc fm .i>
o* and •d)ac«Ml to Mllaada bibllal, «rl Uodj b^t|t«l. on ww) adia.*!)! i«
atlo. ND|»« Mr >*«UM *li««*« 40d ••cava- cunttruinon »li«.
•••DorMr lo«« el I loo Mf cauM
• lldllU. •io>loo tat M
-------
• Table li "
ASSBOUB ALTOMATIVB EVALUATION aHMJUUR
Criteria
Technical
feasibility
Public Health and
Meltare
Ct»lrona»nlel lapect
All Ho ActloB.UI
Mi tell Cap. 141
Alt LM Para. Cap,
Slurry Hall, W Coatrol/
TraaUaat. Ul
A4i LOT Para. Cap,
Gradleat Coatrol/
141
bcavat Ion/Of (alta
Olapoaal. AM
A6i Stabllltatlon/
lea. Ul
N.A.
Public baaltk kaurda
and contaalaaat
•Igratlo* aaaltlaated
Contaaloeat
mitigated
.... •«•• ooaatmctloa lapacta
far aa adjaoaat araaai
ataMlwa OM
aa Al.
1M
Rlttgataa direct caatact
••gaattoa af O»a-,
•atar
M U
lee*
aa Al
CoMtructiga Up*ct« on
•djaont prapartu*
could ba •loBlflcaat
•l>k of direct couct
alUla*Ud| laaattloi
al ooataalaatad Mlar
alulaatadi rlaU ara
traaafanad ta aaotkar
•hart-tat*
rltk
(aurc*
aa Al
rvtercd
•ItkU JO-M
potMtUI
to Al. but Bora
•K«B«I» cwstructloa
lapact*
uaprovae.
ka»di- and
(lald-acala taatloo,
U«k of dlract coouct !•••
tban Al and AJ| laoactlon ol
coataalMtad Mlar pratmttd
£1*1 Ur to Al
ftaaant Itortb Caat
Araa A
Araa •
Araa C
Araa 0
Total (All dparabla Halt*) $iao,20O
)!.«»,000
1,1*4,000
1,147,000
M.OOO
t?,6M,000
III,204.000
a.Ml.OOO
12,146,000
110,111,000
110. $00.000
•io.yw.ooo
tit,1*7,000
J.416,000
12,1*1,000
}4*,IW,000
SI9.41I.OOO
2,»9I.OOO
l*.t)4.000
141.94S.OOO
HI - lutltatlaaal 4 lafraatructural (Dead raatrlctloaa, Ceoclag, AM, aoaltorlag)
*B • Alienate Hater Cvpply
Itieae coata do not reflect deletion ot "tenciitg" from Alternatives 2, 3, 4
-------
-19-
REMEDIAL ALTERNATIVES
Elements Common To Most Alternatives
All of Che alternatives include the provision of an alternative water
supply to homes that currently rely on the Tabb or Yorktown Formations for
potable water downgradient of the site. The homes along Wolf Trap Road will
be connected to the existing Newport News waterline and the homes along Aliens
Mill will be served by extending the existing waterline to Aliens Mill Road.
During the design of the remedial alternatives, a survey of the existing water
supplies will be conducted. The survey will determine the number of homeowners
currently using the Tabb or Yorktown Formations for drinking water and the
corresponding number of connections to the alternate water supply lines.
All of the alternatives except Alternative 5 (excavation and disposal)
would incorporate the following actions. The description of these technologies
is not repeated in the discussion of each of the alternatives.
° Deed Restrictions
Efforts will be made to obtain deed restrictions on the
flyash pits and immediately adjacent areas. These restrictions
would prohibit excavation of soil and restrict building
construcion onsite. Withdrawal of ground water would also
be restricted to prevent contact with or ingestion of
contaminated groundwater.
0 Monitoring Program
Post closure monitoring program for ground water and surface
water consistent with "applicable" or "relevant and appropriate"
federal public health standards will be designed and implemented.
Ground water and surface water will be monitored over time
— to evaluate the effectiveness of remedial actions and to
determine whether receptors are threatened. Samples will
be taken periodically at various locations to determine if
the remedial action should be adjusted and/or if additional
corrective actions are warranted.
Alternative 1 - No Action
This alternative includes the deed restrictions and monitoring program
described in the introduction of the section.
Under the no action alternative, no remedial actions will be implemented
at the site and the site will remain in its current state.
-------
-20-
0 Environment and Public Health
Under chis alternative, contamination of the surrounding
environment of the fly ash pits may remain.
At the Chisman Creek site, the continued presence of
contamination from the fly ash pits may have adverse effects
on the public health and environment. The human consumption
of ground water may present a cancer risk. Exposure to fly
ash through ingestlon and/or inhalation presents a health
concern for area residents. Dermal contact or ingestion
of contaminated surface waters and sediments during
recreational activities may add to the health risk. Fish
and other aquatic biota would continue to be exposed to
contamination, which could be passed onto the local
population through ingestion.
This alternative would not prevent, mitigate or minimize
threats to public health and the environment and also does
not meet the "applicable" or "relevant and appropriate"
Federal public health requirements.
Cost
The operation and maintenance (O&M) costs associated with
this alternatye are for periodic monitoring, which are
estimated to be $17,900 annually for 30 years.
Alternative 2 - Soil Caps
This alternative includes the deed restrictions and monitoring program
described in the incroduction of this section.
Thia_alternative would involve placement of a 14.3-acre soil cap over
Area A, a 4.8-acre soil cap over Area B, and a 13.4-acre soil cap over Area
C and the construction of runoff diversion and conveyance facilities.
Regrading of Che areas would be necessary prior to placement of the caps.
The cap would be a soil layer overlaid with topsoil and vegetative growth.
Runoff detention measures would be implemented as necessary.
0 Environment and Public Health
Capping protects the public by eliminating direct contact with
the fly ash and by eliminating wind and surface water erosion.
Cost
The cost of this alternative depends primarily on the amount and
availability of materials used for capping. O&M costs include
-------
-21-
Che cose of inspection and maintenance of the caps and periodic
monitoring. The total estimated cost for this alternative is
57,680,000.
Alternative 3 - Construction of a Slurry Wall and Cap
This alternative includes the deed restrictions and monitoring program
described in the introduction of this section.
This alternative involves the construction of a slurry wall around each
of the fly ash pits in order to contain the contaminated waste and divert
the ground water (Figure 5). The pits would then be capped to minimize
infiltration and leachate generation in the manner described in Alternative
2 above. A discussion of slurry wall construction follows*
At the Chisman Creek site a slurry wall could be constructed around
the fly ash pits and keyed into the Yorktown formation which is of low
permeability and also has a chemical composition that minimizes migration
of contaminants (Figure 6). At the Chisman Creek site, a soil-bentonite
slurry wall would be used. This type of slurry wall offers the lowest
installation cost, the lowest permeability, and the widest range of chemical
corapatabilities. While a number of chemical compounds may affect permeability
of a soil-bentonite slurry wall, metals are not included in these compounds.
0 Environment and Public Health
The major environmental and public health concerns presented by
this alternative involve the excavation of contaminated materials
for the constuction of the slurry walls. The excavated material
must be properly disposed of and precautions muse be taken to
prevent emissions from the site and protect workers and the
public.
The slurry walls would be constructed into the Yorktown Formation
and would be, in affect, a hanging slurry wall, which would allow
- ground water to migrate under the wall into the Yorktown
Formation and up into the fly ash pits. The continued flow of
ground water requires ground water gradient controls, most likely
accomplished by interior drains with the flow pumped to adjacent
streams. This pumping would continue forever, thus reducing the
long-term reliability and effectiveness of this alternative.
Cost
Costs for slurry walls are usually expressed in costs per unit
area of wall (dollars per square foot). Total costs are deter-
mined by the length and the depth of the walls as well as the
soil type in which the wall is constructed. The estimated cost
for this alternative is $30,117,000.
-------
Figure 5
ASSEMBLED ALTERNATIVE A.
CHISMAN cnttx, fs
-------
Typical 5'
Impermeable Cap
-Slurry Wall
Slurry Wall
6" Perforated
Subsurface
Drain
No. 78 VOH & T Stone For Drainage
Geotextile Filter Fabric
Limits of Flyash Pit
Tabb
Formation
York town
Formation
Not to Scale
Figure 6
TYPICAL SECTION
SLURRY WALL WITH PERIMETER
SUBSURFACE DRAINS
r ••
CHISMAM CHt IK I r 1
-------
-24-
AlcernaCive. 4 - Low-permeabili cy Cap, Gradient Control/Treatment
This alternative includes che deed restriccions and monitoring program
described in Che introduction of this section.
This alternative applies only to Area C. This alternative, considered
as a whole, was determined to be unsuitable for Areas A and B because it
would have negative impacts on nearby surface waters and the Yorktown
Formation. (See FS ac 3-12).
This alternative would include the construction of a low-penneabllity cap
over Area C. A subsurface drain would be installed around the pit in order
to lower the water table below the bottom of the flyash. A 6-inch perforated
pipe drain system would extend around the west, south, and ease sides of the
pit (Figure 7). The drain would be approximately 15 feet below the surface
along the west side of Area C (800 feet in length) and 10 feet in depth
along the south and east sides (1,400 feet in length).
The drain would collect approximately 30 gpm imitially and 8 gpra upon
attainment of steady-state conditions, approximately one year after instal-
lation. Ground water collected during the initial drawdown period would be
conveyed to a treatment plant onsite having a capacity of 50 gpm. After the
ground water table was lowered beneath the flyash pit, the quality of the
collected ground water would improve. The quality of the ground water would
be verified by the periodic sampling. It is expected that after approximately
one year, the collected ground water would not require treatment and could
be directly discharged to Chlsman Creek or its tributaries.
0 Environmental and Public Health
The major environmental and public health concerns involve the
excavation of contaminated materials for the contruction of the
sub-surface drain. The excavated material must be properly
disposed of and precautions must be taken to prevent emissions
from the site and protect workers and the public.
Cost
Coses for the subsurface drain is dependent on final depth of
the drain and the amount of excavation necessary for the
construction and soil type in which the wall is constructed.
The estimated cost of this alternative for Area C is $10,409,000.
Alternative 5 - Excavation and Offsite Disposal
This alternative involves the excavation of approximately 504,700 cubic
yards of fly ash from the pits and its transport to a sanitary landfill.
-------
Figure 7
ASSEMBLED ALTERNATIVE A4
CHISMAN C8CEK f S
-------
-26-
This alternative would provide one of the highest levels, of cleanup ac the
Chisraan Creek site. It would also be one of the most expensive.
Excavation and removal of contaminated soil and fly ash would eliminate
the source of contamination at the site and shorten the time required for
long-term monitoring. Problems associated with excavation, removal, and
off-site disposal are of concern due to worker safety, short term impacts
and cost. Short term impacts include dust emissions and contaminated run-off.
Additionally, care must be taken during transport to prevent spreading of
the contaminated material. Costs associated with off-site disposal are high
and therefore may exclude complete excavation and removal as a viable
alternative. Additionally, proximity of a sanitary landfill willing to accept
these wastes may have a substantial impact on transportation costs. It is
estimated that three years would be required to complete this removal and
disposal operation.
0 Environment and Public Health
The implementation of this alternative would eliminate any long
term problems and concerns associated with fly ash in the pits.
Environmental and public health risks are those associated with
excavation and transport of contaminated material. Careful
planning and execution would minimize many of these concerns.
Cost
Costs for excavation and disposal are given in dollars per cubic
yard. The estimated cost of this alternative is $49,106,000.
Factors affecting the cost of this alternative include:
- Volume of waste to be excavated
Hauling distance
Health and safety requirements
Disposal fee
The excavation and off-site disposal alternative would be the most costly
alternative for the Chisman Creek site due to the large volumes involved.
Alternative 6 - Solidification/Stabilization and Cap
This alternative includes the deed restrictions and monitoring program
described in the introduction of this section.
Under this alternative, proprietary equipment would be utilized to
convert the flyash in the pits into a relatively impermeable concrete-like
monolith. Prior to the initiation of operations, bench-scale testing would
be conducted to determine treatment requirements for the flyash. Three
rigs would be utilized to implement a two-step treatment process at the
-------
-27-
site: immobilization using ferrous suifate and solidification with hydrated
Lime. Approximately 2-1/2 to 3 years would be required to complete the
stabilization/solidification of the three pits. Upon completion of the
treatment process, a vegetated soil cover would be installed over the
solidified monolith. Implementation of the process would be virtually
identical cor all chree flyash pits.
0 Environment and Public Health
This alternative prevents surface infiltration and leachate
generation at the site. The soil cover isolates the waste
from the surrounding environment and public.
0 Cost
Cost for the S/S processes depends on a number of factors in-
cluding the reagents used for solidification/stabilization,
dosage rates and transportation costs. The pounds of reagent
required per volume of waste is generally used as a basis for
cost estimation. The estimated cost of this alternative is
341,729,000.
RECOMMENDED ALTERNATIVE
Section 300.68(i) of the National Contingency Plan (NCP) states that
the appropriate extent of remedy shall be determined by the lead agency's
selection of the remedial alternative which the agency determines Is cost-
effective (i.e., the lowest cost alternative that is technologically feasible
and reliable) and which effectively mitigates and minimizes threats to, and
provides adequate protection of public health and welfare, and the environment.
This provision further states that, except as otherwise provided, this
will require selection of a remedy that attains or exceeds "applicable" or
"relevant and appropriate" Federal public health and environmental requirements
that have been identified for the site. In selecting the appropriate extent
of remedy from among the alternatives that achieve adequate protection of
public health and welfare and environment, the lead agency must consider cost,
technology, reliability, administration and other concerns, and their
relative effects on public health and welfare and environment NCP §300.68(1)(2).
Based on our evaluation of the proposed alternatives, the public comments
and the information received from State of Virginia, we recommend the following
remedial alternative, which is a combination of Alternatives 2 and 4.
1. Areas A and B - These flyash pits will be capped with a soil layer
overlaid with topsoil and vegetative growth.
-------
-28-
2. Area C - This tly ash pic will be capped with-a low-permeabilicy cap.
This would consist of a compacted soil layer overlaid wich topsoil
and vegetative growth. A subsurface drain will be installed on
the west, south, and east sides of the pit in order to lower the
water table below the bottom of the fly ash. Ground water collected
during .the initial drawdown period will be contaminated from the
fly ash and will be conveyed to an onslte treatment plant. Once
the ground water is uncontaminated, the treatment will cease. This
alternative is preferred at Pit C because, in addition to controlling
surface runoff and direct contact, it would eliminate the migration
of ground water contaminated with Nickel by drying out the pit.
3. Alternate Water Supply - The homes along Wolf Trap Road will be
connected to the existing Newport News waterline and the homes along
Aliens Mill Road will be served by extending the existing waterline
to Aliens Mill Road. During the design of the remedial alternative,
a survey of the existing .water supplies will be conducted. The survey
will determine the number of homeowners currently using the Tabb or
Yorktown Formations for drinking water and the corresponding number of
connections to the alternate water supply.
4. Land Use Controls, and Monitoring - EPA will attempt to obtain deed
restrictions or other controls should be placed on the fly ash pits
and immediately adjacent areas. These restrictions will prohibit
excavation of soil and restrict building onsite. These controls
should also include restrictions of ground water use in the fly pits
and down gradient of the fly pits in the Table Formation.
Post-closure monitoring program for the ground water and surface
water will be designed and implemented
Operation and Maintenance •
At Area C, the subsurface drains will initially collect ground water
that has been in the fly ash pits. This ground water will be contaminated
with inorganics and require treatment by an onsite treatment plant. The
creatmens-will eventually cease once the level of contaminants decrease to
acceptable levels.
The caps will require periodic inspection to maintain the caps and
eliminate any bore animals.
Monitoring will continue adjacent to the fly ash pits to track the
migration of any inorganics that would cause an adverse effect on human
health.
-------
-29-
Consiscency With Other Environmental Laws
The decision co select a remedy which will lower .Che ground water cable
ac Area C was based on consideration of relevant and appropriate criteria,
advisories and guidance. Nickel is an Appendix VIII constituent regulated
under the Resource Conservation and Recovery Act (RCRA). The level of nickel
(up to 1400 mg/1) found in monitoring well 3 to the east of Area C was above
EPA's recommended intake for the prevention of chronic effects (350 ug/1) and
EPA's recommended intake for the prevention of subchronic effects (700 ug/1)
identified in EPA's Health Effects Assesment Document For Nickel (EPA/540/1-86-018,
September 1984). Additionally, the levels in well 3 and well 5, which is to
the west of Area C (up to 300 ug/1) were above EPA's draft Drinking Water
Health Advisory level (150 ug/1). EPA's Ambient Water Quality Criteria for
protection of fresh water aquatic life (88 ug/1 to 280 ug/1) and EPA's Ambient
Water Quality Criteria for the protection of salt water aquatic life (17
ug/1) were exceeded in both wells. Since these ground waters discharge to
nearby surface waters, the Ambient Water Quality Criteria were appropriate
for consideration. The recommended action is designed to lower the water
table around Area C so that the relevant and appropriate criteria, advisories,
and guidance for nickel will not be exceeded.
Ground water outside of Areas A and B is contaminated with IDS and sulfates.
EPA has concluded that achievement of the SMCL's for these compounds also
is not an "appropriate" Federal public health or environmental, requirement
because these standards were established merely to minimize tase and odor
problems for public drinking water supplies. No exceedances of primary
MCL's, which are established to protect public health, have been Identified.
Also, around all the fly ash pits there are elevated levels of vanadium and
molybdenum. There are no "applicable" or "relevant and appropriate standards"
for vanadium and molybdenum. Vanadium and molybdenum are not RCRA Appendix
VIII constituents nor are there Federal Ambient Water Quality Criteria, '
Federal Health Assessment Documents or Drinking Water Health Advisories for
these two compounds. EPA has concluded that actions to remediate the vanadium
and molybdenum ground water contamination are not necessary to protect human
health.
RCRA hazardous waste requirements are not legally "applicable" at this
site because fly ash Is specifically exempted under RCRA (See 40CFR 5261.4(b)(4)).
However, portions of the RCRA closure requirements pertaining to closure and
post-clostfre care of landfills (see 40 CFR §264.112 - §264.120 and 40 CFR
§264.310) and ground water monitoring (40 CFR Part 264, Subpart F), as well as
corrective action requirements (40 CFR §264.100) are "relevant and appropriate"
requirements for this site.
The RCRA final cover requirements of 40 CFR $264.310 are relevant and
appropriate to the actions recommended at Area C because these requirements
are designed to apply to situations where the migrations of liquids through
a site must be minimized. Since an objective of the preferred alternative
for Area C is to mitigate the ground water contamination, percolation from
rain water and surface run-on and run-off oust be minimized. For Areas A
and B, the objectives of the remedial action are only to prevent direct
contact and to minimize erosion, therefore, only those portions of 40 CFR
§264.310 which address minimization of erosion and prevention of direct
contact are relevant and appropriate.
-------
-30-
Cercaln ground water monitoring requirements of 40 CFR Part 264,
Subparc F are relevant and appropriate to all three areas because it is
necessary chat EPA monitor the ground water to verify the effectiveness of
t.;e remedial action. The placement and construction of the wells will be
determined during design. Those portions of the RCRA regulations requiring
the monitoring of Appendix VIII constituents are not appropriate. The RI
data shows that sampling is only necessary for priority pollutant metals
plus TDS, sulfates, vanadium and molybdenum. The latter four compounds will
be analyzed for because they are good indicators of fly ash contamination.
The corrective action requirements of 40 CFR §264.100 are relevant and
appropriate at Area C because the contamination outside of Area C represents
a release of a hazardous constituent(s) which may threaten public health, as
discussed above. At Areas A and B the groundwater contamination will not
threaten public health, therefore, 40 CFR §264.100 is not appropriate for
application at these two areas.
Offsite surface water discharges from the drain system around Area C
must comply with the technical National Pollutant Discharge Elimination
System (NPDES) requirements. The treatment system must have adequate capacity
to meet the NPDES requirements.
Flood Plain/Wetlands Assessment
The recommended alternative may affect the flood plains/wetlands near Area
C to the extent that flows in the streams may be slightly altered. The drain
and cap may change shallow ground water movement resulting in a minor altering
of the flow in the intermittent area west of Area C and in the segment of
Chisman Creek which receives ground water from Area C.
Impacts in the flows of these surface water bodies is unavoidable because
Area C is located so close to these streams. As the ground water outside of
Area C is contaminated, particularly with Nickel, a remedial action is necessary
for the ground water (see the previous discussion). The other remedial
alternatives considered were rejected because they would not remediate the
ground water contamination at Area C (no action and alternative 2), were
unreliable—(alternative 3) or were not cost-effective (alternative 5 and 6).
The recommended alternative has received the approval of the State and local
governments.
With proper design flow, changes should be minimal and, therefore, the proposed
action should have little or no impact on the natural or benefical values of the
flood plain and wetlands. It should, in fact, have a net positive impact because
contaminant loading to the creeks will be reduced. To insure this, the alternative
will be designed so that one drain can discharge on the northwest side of Area
C and the other can discharge on the eastern side of Area C.
-------
-31-
The. snail ponds In che area will not be affected by the action at Area C
because there is a topographic divide between Area C and the-ponds, which
separates the ground flow systems. The actions at Areas A and B will have no
negative effects on the ponds or any other wetlands because the low-permeable
soil cover will have no impact on ground water flows. The actions at Pits A
and B should, in fact, have a positive impact on the ponds by reducing runoff
and erosion into the ponds.
The impact of che site on the creeks, ponds, and aquatic life is being
further evaluated as part of the study being conducted by the U.S. Fish and
Wildlife Service. Another Record of Decision will be developed to directly
address the need, if any, for remedial action in these areas after the studies
are completed.
EVALUATION OF ALTERNATIVES NOT SELECTED
Alternative No. 1 - The no action alternative was not selected because
the fly ash would erode into adjacent streams and ponds may continue to pose
threat to public health and the environment. Also, the fly ash pits would
remain accessible to residents and ground water contamination outside of
Area C would not be remediated.
Alternative No. 2 - This alternative is rejected for Area C because
a soil cap alone will not effectively mitigate the ground water contamination
caused by Area C.
Alternative No. 3 - The alternative includes a low-permeability cap,
slurry walls, interior drains for ground water control. The slurry walls
would be constructed into the Yorktown Formation and would be, in effect,
a hanging slurry wall, which would allow ground water to migrate under the
wall into the Yorktown Formation and up into the fly ash pits. The contin-
ued flow of ground water requires ground water gradient controls, most likely
accomplished by interior drains with the flow pumped to adjacent streams.
This pumping would continue forever, thus reducing the long-term reliability
and effectiveness of this alternative. Additionally, the degree of risk to
human health and environment presented by ground water from Areas A and B
does not warrant the added expense of eliminating ground water from these
areas.
Alternative 5 - This alternative includes excavation of offsite dis-
posal of fly ash and was not selected because It is not cost-effective.
Excavation and off-site disposal would only move the fly ash to a different
location. During construction, this alternative would cause dust emissions
for a number of years while the fly ash is being excavated. Since the
risks posed by the fly ash can be effectively and reliably mitigated for a
cost of $14,119,000, the significant cost, $49,106,000, for off-site disposal
and management of the fly ash is unjustified.
-------
-32-
Alcernative 6 - This alternative caLls for in-place stabilization/solidi-
fication and was not selected because of it not cost-effective. As discussed
in Alternative 5, the long-term risk of the fly ash pits can be effectively
and reliably mitigated with alternative 2 and 4 at a cost of $14,110,000, as
opposed to a cost of $41,945,000 for this alternative.
Estimated Schedule *
Approve ROD 9/86
Award Superfund IAG
to US Corps of Engineers for Design 11/86
Start Design 5/87
Design Complete 10/87
Award Construction Contract 2/88
Start Construction 4/88
* Dependent upon CERCLA reauthorization
-------
CHISMAN CREEK SUPERRJND SITE
GRAFTON, TORK COUNTY, VIRGINIA
RESPONSIVENESS
SEPTEMBER 1986
This conrunity relations responsiveness sunmary is divided into the
following sections:
Section I.
Section II.
Section III.
Section IV.
Overview. This section discusses the EPA's preferred
remedial" action alternative and the anticipated public
reaction to this alternative.
Background of Community Involvement and Concerns.
This section briefly describes the history of
community interest and concerns that arose during
remedial planning activities at the Chisraan Creek
site.
Summary of Major Comments Received during the Public
Comment Period and the EPA's Responses to these Comnsnts.
Comments received are summarized and categorized according
to topics. Garments are separated into 3 groups:
A. Oral comments received before the public meeting,
September 22.
B. Oral contents received during and after the public
meeting, September 22.
C. Written contents.
Remaining Concerns. All remaining concerns that the
EPA or the State of Virginia should be aware of during
future remedial activities•for this site are discussed
in this section.
In addition to the above sections, Attachment A provides a listing of
community relations activities that were conducted during the remedial
response activities at the Chiattan Creek site.
-------
I. OVERVIEW
A short site history, as --ell as the Feasibility Study findings and
cleanup options have been discussed previously in this EDO. The
preferred alternative consists of installation of a clay cap over Pit C
and soil caps over Pits A & B. Pit C would be dewatered through use of
a subsurface drain. In addition, an alternate water supply would be
provided for those residents on Aliens Mill and Wblf Trap ftoads whose
wells draw fron the shallow aquifer. Land use controls would be needed
to prevent damage to the caps.
/*
A primary concern of local officials and residents is the nature of land
use controls intended for implementation. Citizens have voiced a strong
preference that the pits not be fenced. It is suggested they be used as
parks. There is little argument from the community regarding the overall
goals and techniques outlined in the Preferred Alternative Fact Sheet and
in this ROD. However, further study of ground water movement and area
hydrogeology have been suggested.
II. BACKGROUND OF CCftKJNITY INVOLVEMENT AND CONCERNS
Several community groups have been involved in the study process at the
Chisman Creek Site since it was placed on the NPL in 1981. That involvement
has been coordinated by the York County government and the Chesapeake Bay
Foundation and has now grown to include many environmental and academic
institutions. EPA's community relations effort began with a public
meeting to discuss the RI/FS workplan in April 1984 and has continued
with door-to-door visits, small group meetings and additional public
meetings. The level of concern and awareness has varied, reaching peaks
at the RI public meeting in December 1985 attended by 120 residents, and
the FS public comment period from August 26 to September 25.
The primary emphasis of the camunity has been on protecting the ground
water which is threatened by the site and on improving the overall quality
of Chisman Creek. Other issues include: the dangers of direct exposure
to flyash, Virginia Power's liability for the flyash pits and the future
use of the pits and the land surrounding them.
Near the cutset of the public comment period, the York County Board of
Supervisors-organized a Stewardship Committee to act as an advisory board
regarding the Chisman Creek Site. This board .included approximmtely 13
members representing such organizations as the Chesapeake Bay Foundation,
the Virginia Institute of Marine Sciences, William and Nary College, etc.
This board provided most of the public input during the cement period.
-------
-J-
III. SUMMARY OF MAJOR COMMENTS. RECEIVED DURING THE PUBLIC COMMENT PERIOD
.AND THE EPA'S RESPONSES TO THESE '
A. Oral Comments Received Before the Public Meeting , September 22.
I) Areas of Responsibility
Commentor; Who in the state is involved with the ROD?
Responder; The State Health Department and the State Department of
Natural Resources have been working with EPA.
Commentor; Vhere does the York County Board of Supervisors cone in?
The Stewardship Committee serves as an advisor to that group.
Responder; EPA solicits recommendations fron local government and
Garments from both the community and the responsible party. Local
government is not in the chain as a decisionmaking body, but local
officials have a very important role in stating what they believe
is correct or not correct to the state and EPA. EPA is seeking
guidance from those officials in preparing the ROD.
Commentor; >hat happens if the responsible party does not implement
the cleanup?
Responder; EPA will initiate the cleanup under Superfund and seek
reimbursement from the responsible party. Under the current CERCLA
law, the ability to tax has expired; however, the authority to clean
up sites remains. Both houses of Congress have passed reauthorization
of a Superfund bill, and the conference committee has agreed on all
issues except one, the tax issue. Vte hope to have a resolution of the
tax issue by the beginning of October. If we do not, EPA will not
have the ability to fund the next step: preparation of plans and
specifications (remedial design). EPA can complete existing phases
but cannot start new phases.
2) Costs and Phasing
Commentor; At what point does th* state become committed to he
cleanup?
Responder; The state's catnibnent occurs. when plans and specifications
are complete and available for use when selecting a contractor to
implement the cleanup. Prior to that time, EPA signs a contract with
the state of Virginia to arrange for the money to be paid.
Commentor: Is there a process of reparation for the owners of property
• comprising Superfund sites?
Responder; There is no provision for compensation of site owners in
the current Superfund legislation. Property owners are potentially
responsible parties.
-------
Conmentor; How long will it be before remedial action begins?
Responder; We are not sure; it depends on who does the work and
the planning and on when a final decision is trade.
Conmentor; Could Pits A and B be addressed, and the best remedy for
Pit C be decided on later?
Responder: EPA may negotiate with Virginia Power later concerning this
possibility. Such negotiations would address those details that
might call for the Stewardship Committee's alternative suggestions.
The purpose of this meeting is to focus on the FS alternatives.
3) Property Ownership and Use
Commentor; Who owns the property once the problem is corrected?
Responder: Property does not change hands unless the owner decides to
sell it. The state would enforce land use restrictions. The county
has mentioned using the land for recreational purposes. EPA does not
want any disturbance of the site that would destroy the cap. Since
integrity of the cap must be preserved, there must be limited usage.
*
Conmentor; Who enforces the limited usage? Who is responsible if
someone Ts injured because of the fence?
Responder; The purpose of the fence is to prevent unintentional
access. The operation and maintenance of the site will be the state's
responsibility. However, liability is still with the property owner.
Commentor; What kind of uses are acceptable in the eyes of EPA?
Responder; An acceptable use is any use that would not affect (1) the
integrity of the caps at the site, (2) the state's ability
to monitor the wells, and (3) the public health, which would eliminate
use of the groundwater in the area. Upon completion of the cap, EPA
will outline what it believes will be necessary to ensure the integrity
of the land.
Coanentor; We do not want to see fences on the property. He would
rather see sane use of the property.
e>
Responder: EPA will consider alternative access restrictions.
4) Leachate
Ccanentor; Does it make any difference if vanadium and nickel get
into Chignon Creek? What happens if those substances migrate into
that area?
Respondert The ecological effects of vanadium and nickel contamina-
tion are being examined in the U.S. Fish and Wildlife study now
underway.
-------
5) Drainage Ditch and Cap
The Stewardship Committee and EPA discussed the effectiveness of digging a
drainage ditch on three sides of the pit.
Responder; We have evaluated this option on a very conservative
basis and we believe it would be successful. We feel the combination
of the drainage ditches and the cap will dewater Pit C.
Connentor; The studies were conducted during a dry period. You haven't
really seen the pits during wet periods. What type of vegetation
would be suitable?
Responder; Regarding the vegetative cover of the cap, certain types
of vegetation are unsuitable (deep rooted trees, etc.). EPA will
propose a type of vegetation to be used that will not h
-------
-o-
Camaentor; Vfcat is an acceptable concentration of nickel in the wells?
Responder; An acceptable level is 600 micrograras per liter or less.
Qjiinentor; How far away frcra the pits has EPA tested to see how far
the contamination has spread? Can you give a radius in miles?
Responder; All wells around Pit C have been examined. These wells
are loca"tid at the hones where we originally found contaminants
(directly across Wblftrap Road). Significant contamination is found
only in the shallow aquifer. If you go below about 20 feet deep,
there is a higher pH and contamination is not found.
Conrentor; Are there other health hazards besides drinking water,
such as children playing in the water? On a scale of 1 to 10, can
you rate the dangers?
Responder; Beside the fact that the groundwater is somewhat
contaminated, EPA doesn't see an immediate danger to, for example,
children playing in the water. The danger is in the flyash contained
in the pits. EPA plans to cover this flyash and to be sure there is
no additional damage to whatever cap is put on the pits.
Couiuentor; People are generally unaware of what is going on at that
site. Some people are here because I knocked on their doors. I'm
surprised at the lack of representation.
Responder; A year ago when we first began to work in York County,
EPA representatives went out and knocked on doors to notify people
of what we were doing. We worked through the county offices to get
an insert in the county newsletter. We will continue to try to keep
the public informed through meetings and mailing lists, but we
appreciate your efforts in speaking to your neighbors.
2) Land Use
Carmen tor; Did the subject of land use or acquisition of private
property come up?
Responder; CEFCLA allows EPA to take the action we are proposing.
The laws-allow EPA to take remedial response actions it deems necessary
at Superfund sites. All property owners taave been sent notice letters
identifying them as potential responsible parties EPA has the legal
ability to go in and take action.
Comment or; Does the proposed cleanup remove the Chisman Creek site
from the Superfund list? Somehow the problem sounded much more
•, serious when we first met than it sounds now.
Responder; The cleanup action will not immediately remove the site
from the Superfund list. Only when it can be shown that there is no
longer any significant danger due to the site can it be removed
from the list.
-------
Connentgr; At the first meeting, many of us were prepared for a
conflict. A Virginia Power representative said that if EPA did not
correct the problem, Virginia Power would. Virginia Power would- pay
all bills and take fast action. In newspaper reports since then,
Virginia Power keeps trying to downgrade the problem. Virginia
Power now says t^iat if EPA doesn't clean up the problan, they will
do it — if they have to. If Virginia Power was willing to pay for
the cleanup when it was a lot more than i* is now, why doesn't EPA
clean up the site now and send Virginia Power a bill?
Responder; It is a fact that Virginia Power can clean up the site
faster.Rather than using EPA's money up front, EPA would like to
reach an agreanent with the responsible parties so they assune the
cost. EPA prefers not to spend the taxpayer's money first. Seme
cleanups cannot be accomplished through agreements with responsible
parties, and EPA prefers to use Superfund for those instances.
3) General Questions and Comments
Conmentor; How do you determine liability?
Responder; For questions regarding release of liability, you should
contact the EPA legal department.
Cumientor; Are there other places like this in the U.S.? Is
technology being used from these other sites?
Responder; Yes, there are similar sites, but not on the NPL.
EPA representatives were not aware of the specific technologies
being used at those sites.
Coanentort Is there a health risk after the pits are capped at those
sites?
Respondert Vte do not have much information about exposure risks at
capped sites. Under the new laws, the Center for Disease Control
will select an area and will perform extensive studies to obtain
information about how people's health is being affected by these
sites.
Conmentsg: Vtiat is the cost to excavate the pits?
•
Respondert To excavate the pits would cost about $49 million.
Coanentor: Why is that figure so high?
Responder; There will be approximately one million cubic yards of
ash haul "away from all pits, and that material must, be disposed at a
federally approved hazardous waste facility. Tipping fees at such
facilities are extranely high.
Commentor: When will the water lines be installed?
-------
Responder; The answer depends on who pays for installation and how
long it takes to get a contractor. When an agreement is reached
with the responsible party, EPA can set up a timetable.
Cunnentort In the meantime, should residents have their water
examined?
Responder; EPA does not believe .there is currently a problem with
the water related to this site.
(Fran the director of the County Department of Public Utilities) My
office will help you find a place to have water samples examined.
However, the water in Chianan Creek area was "bad" to start with.
There is no "good" water in any well below the Naval Weapons Station.
You will probably want to find out whether there has been pollution
of the well from nearby septic tanks.
Commentor; Is there something such as putting up signs that can be
done to keep people out of the area, particularly from kicking up
the flyash?
Responder; We can explore the options for keeping people out. Only
in emergency conditions can EPA put up signs. We will see if
something can be done, however.
C. Written G-uintmts
1) The following Garments were received from the Stewardship Committee
in a resolution through York County Board of Supervisors Chairman
Ben Rush.
Commentori The committee generally endorses the preferred remedial
alternative, but believes the following issues should be studied
further:
Ground water flew through the pits. The committee is concerned that
the RI data was collected duriny a particularly dry period and may
not be representative of typical conditions.
equilibrium and exchanges between water bound particles and the water
flowing-fefarough those particles.
Geological and hydrogeological conditions and the permeability
of flyash deposits.
Alternate access restrictions. The committee does not support
an option which calls for chain link arid barbed wire fencing
around the pits.
Final ransdial actions should be contingent upon the findings of
the U.S. Pish and Wildlife study new underway.
-------
Sesponder; SPA will cvitinua to «ork with the Ste^ar.iship Commutes
and York Count/ tD :ta:<
-------
-10-
Responder; The NC? requires, with limited exceptions, EPA to select a
remedy that attains or exceeds applicable or relevant and appropriate
Federal public health and environmental requirements (see section 300.68
(i)). Guidance for implementing this requirement is .provided in an EPA
memorandum titled "CERCLA Conpliance With Other Environmental Statutes"
dated October 2, 1985 (see 50 Federal Register 47946 - 47950, November
20, 1985).
The conmentor correctly notes that thero are no MCLs for nickel
established under the Safe Drinking Water Act. However, EPA policy
identifies other Federal criteria, advisories, guidance, and state
standards to be considered (see 50 Federal Register 47949). Relevant
and appropriate guidance to be considered in the case of nickel are:
Health Effects Assessments (HEA), Federal Water Quality Criteria (AWQC),
and Health Advisories. For nickel there is a HEA (see EPA/540/1-36-018,
September 1984 or NTIS-PB86-134293/AS)*, there is a proposed AWQc (see
51 Federal Register 8361, March 11, 1986) and there is a draft drinking
water Health Advisory (October, 1985). Since the ground waters discharge
to nearby surface waters, the AWQC were appropriate for consideration.
As discussed in the Record of Decision, under "Compliance With Other
Environmental Laws", the measured levels at monitoring well 3 exceed
all the guidance levels and at monitoring well 5 sane of the levels
are exceeded. Nickel is also an Appendix VIII constituent under RCRA.
Because the levels of nickel outside of Area C exceed appropriate
guidance and because nickel is an Appendix VIII constituent that has
been released beyond the boundaries of Area.C, and because it is
necessary to protect public health from these releases, the relevant
and appropriate sections of RCRA would authorize a corrective action to
be taken. Additionally, under EPA's CERCLA authorities, EPA believes
a remedial action at Area C is necessary to effectively mitigate and
minimize the threats and to provide adequate protection of public
health and welfare and the environment.
After screening technologies and evaluating alternatives, as
described in the Feasibility Study, EPA found that dewatering of Area
C could be accomplished in a cost-effective manner through the use of
drains and a very low-impermeability cap along with a temporary treat-
ment unit. Dewatering of the fly ash pits will insure that there will
be no release of contaminants into the ground water.
Canmentort The drain system proposed by EPA will be technically
infeasible to implement.
Responder; EPA believes that the drain system can be implemented as
proposed. Construction technologies can be fully evaluated during
design to insure slope stability of the fly ash pit during installation
of the drains.
*Note: EPA's letter of September 17, 1986 transmitted a draft copy
of the HEA, and referenced a federal register notice with a
drinking water guidance on nickel. The HEA was published in
final form, as reference above, with no significant changes
from the draft (i.e. the AIC and AIS values are the sane),
and the guidance level (ISO ug/1) is the sane as the health
advisory level.
-------
-11-
The slopes required for the drains could be less than the l%-2% suggest-*!
by the ccmmentor. The drain must only function to keep the water level
tram rising into the pits; it does not function like a storm sewer, which
is designed to insure a strong gravity flow of water. The drain ;oist be
designed.only to insure that the fluid potential in 'the drain is at
atnospheric pressure so that the water level around Area C will be lowered,
The drains should not cause any significant contamination of the
Yorktown Formation. The ccmmentor was concerned that in its natural
condition, the Yorktown Formation is relatively impermeable to ground
water flow from the Tabb Formation and that the drain would alter these
natural conditions. The RI found that the Yorktown, as defined in the
RI, is naturally permeable and the ccmmentor has not provided any
information to show that the installation of the drains will have a •
significant impact on the degree of interconnection currently existing
between the Tabb and Yorktown Formations.
Commentor; The Public Health and Environmental Evaluation (PHEE)
unnecessarily and inaccurately overstates the potential adverse health
effects.
Responder; The basis for the PHEE calculations are clearly described
in the report. EPA is making its decisions primarily on filtered
samples, as suggested by the commentor (i.e. nickel levels outside of
Area C). EPA recognizes that there is debate over the carcinogenicity
of arsenic, and has taken this uncertainty into consideration. As
sampling results have shown, there are compounds other than nickel that
are elevated in all these disposal area (i.e. chromium, selenium, etc.).
EPA believes the information in the PHEE is useful for evaluating the
risks posed by the site. Based on the RI, FS, the PHEE, and the
documents listed on the ROD's declaration page, EPA believes that there
is sufficient information to select the recommended alternative.
IV. RD1AINING CONCERNS
Community members are adamantly opposed to a remedial solution which
would render the pit areas completely unuseable. EPA has indicated
that it will examine other options for land use control. York County,
the Chisman3Creek Stewardship Committed and Virginia Power have voiced
several suggestions and concerns related to the information in the RI
and FS documents. These concerns are outlined in this document. All 3
groups particularly and the community in general should be a continuing
part of the decision making process regarding this site.
-------
Appendix A
0 April 23, 1984 — EPA held a public meeting on the workplan for
the RI/FS.
9 September 10-13, 1984 — EPA visited residents and distributed
'-. tact sheet which explained future plans for the site.
0 December, 1985 — EPA issued a press release on the RI.
0 December, 1985 — Public meeting on the Remedial Investigation.
9 August 25, 1986 — Local officials and residents were contacted
regarding the release of the Feasibility Study.
9 August 26, 1986 — The FS was distribued to 4 information centers
in the camnunity. A press release on the FS was issued.
9 September 11, 1986 — EPA met with the Stewardship coimi ttee.
9 September 15, 1986 — The ccnment period was extended to September 24.
9 September 22, 1986 — EPA held a public meeting on the FS.
------- |