United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R09-87/015
September 1987
&EPA Superfund
Record of Decision:
San Gabriel, CA
-------
TECHNICAL REPORT DATA
'Pteau ftati iHttmcnont on int rtvent Stfort
NO.
EPA/ROD/R09-87/015
3 (»€Ci"«*r S
.CN NO
4. nrui ANO
SUPERFUND RECORD OF DECISION
San Gabriel Area I, CA
First Remedial Action
OAT«
September 30, 1987
6 MM'OMMINC ORGANISATION COOf
7 AUTHOMIS)
• . MMPOMMING ORGANIZATION R(»ORT NO
to. PROGRAM
•. M«PO«MINO ORGANIZATION NAMf ANO AOOMCSS
NO
1 CONTHACT/GBANT NO
12. SPONSORING AGfNCY NAM« ANO AOOAfSS
.U.S. Environmental Protection Agency
401 M Street, S.W.
-Washington, D.C. 20460
13. TVM Of MCPOMT ANO MRIOO COVCHCQ
Final ROD Report
14. S'ONftOMINQ AOtNCV COOI
800/00
16. SUMLIMINTAAV NOTIS
«. AMTHACT
San Gabriel Area 1, of the San Gabriel Ground Water Basin, is located primarily
underneath the city of El Monte, Los Angeles County, California. In 1980, the State of
California, in an extensive well water testing program in the San Gabriel basin, fo.nn*-"
numerous wells contaminated with TCE, PCE and other chlorinated hydrocarbons. As a
result, the California Department of Health Services (DOHS) directed area public water
companies to implement periodic well testing. State Action Levels for TCE and PCE were
set at five and four ug/1 (ppb), respectively. If alternative methods of reducing TCE
and PCE concentrations below the Action Levels were not effective, wells would be
removed from sevice. In 1983, when EPA became involved in addressing the problem, three
mutual water companies, Richwood, Rurban Homes and Hemlock, had no alternate water
supply and had been providing their customers with PCE contaminated water above the DOHS
Action Level. In May 1984, EPA Region IX's Regional Administrator signed a Record of
Decision (ROD) selecting air stripping treatment as the most cost-effective initial
remedial measure (IRM) to provide the three mutual water companies in El Monte with a
source of uncontaminated water. During the design phase of the IRM, it became apparent
that the cost to construct and operate air stripping systems would be much higher than
estimated in the Focused Feasibility Study and the ROD due to the severe site
constraints associated with these systems. As a result, revised cost estimates have
(See Attached Sheet)
17.
«Y WOAM AMD OOCUMCMT ANAC*»I»
oucflirroM
b.(OtNTlHt*«/OPfN CNQtO TlNMS
CO«ATI Fwld/Growp
Record of Decision
San Gabriel Area I, CA
First Remedial Action
Contaminated Media: gw
Key contaminants: VOCs, PCE
It. OlSTHliUTION STAT1MKNT
Iff. StCUMlTT CLAM ( HIM
None
70
20. S«CU*'Tv CLASS .
2J ••'€•
ftrm 2R4.I (••«. 4.77) •••view* COITION •• O«tOi>(TB
-------
EPA/ROD/R09-87/015
San Gabriel Area I, CA
First Remedial Action
16. ABSTRACT (continued)
been developed for all of the ROD'S alternatives. Based on these revised costs andother
factors, EPA has determined that carbon adsorption treatment is now the cost-effective
alternative to treat the PCE contaminated ground water.
The selected interim remedial action for this site includes: installation of an
activated carbon adsorption system for treatment of well discharge at the Richwood
Mutual Water Company; completion of the design nd development of bid documents for the
Rurban Homes system, monitoring of this system with implmentation of a carbon adsorption
system if monitoring results show an increase in well contaminant levels; and based on
future determinations, if necessary, an upgrade to the Hemlock system. The estimated
capital cost for the selected remedy is $1,616,100 - $1,771,800 with annual O&M of
$181,400 - $303,100.
-------
DECLARATION FOR THE RECORD OF DECISION AMENDMENT
SAN GABRIEL AREA 1 INITIAL REMEDIAL MEASURES
SITE NAME AND LOCATION
San Gabriel Area 1, El Monte/ California
STATEMENT OF PURPOSE
This decision document represents the selected remedial action
for this site developed in accordance with CERCLA, as amended by
SARA, and to the extent practicable/ the National Contingency
Plan.
The State of California has concurred on the selected remedy.
STATEMENT OF BASIS
This decision is based upon the administrative record (index
attached). The attached index identifies the items which comprise
the administrative record upon which the selection of a remedial
action is based.
DESCRIPTION OF SELECTED INITIAL REMEDIAL MEASURES;
An overall area-wide remedial investigation/feasibility study for
the San Gabriel Areas 1-4 sites is currently being conducted.
Although many water companies have been affected by contaminated
wells/ only three small mutual water companies in the City of El
Monte have been unable to provide water that meets EPA drinking
water standards and state recommended action levels. These initial
remedial measures ensure that the population served by the three
mutual water companies are not exposed to unacceptable public
health risks during the interim period before a final remedial
action is selected for San Gabriel Area 1. The initial remedial
measures include the following components:
• Installation of an activated carbon adsorption system for
treatment of well discharge at the Richwood Mutual Water
Company.
* Installation of an activated carbon adsorption system for
treatment of well discharge at the Rurban Homes Mutual Water
Company.
0 Installation of an upgrade to the activated carbon adsorption
system currently being operated for treatment of well discharge
at the Hemlock Mutual Water Company to the design standards
of the systems to be installed at Richwood and Rurban Homes
Mutual Water Companies.
-------
-2-
DECLARATIOMS
The selected remedy is protective of human health and the
environment, attains Federal and State requirements that are
applicable or relevant and appropriate, and is cost-effective.
This remedy satisfies the preference for treatment that reduces
toxicity, mobility/ or volume as a principal element. Finally,
it la determined that this remedy utilizes permanent solutions
and alternative treatment technologies to the maximum extent
practicable.
Judith E. Ayres
Regional Administrator
EPA Region IX
^•30-67
Date
-------
RECORD OF DECISION AMENDMENT
DECISION SUMMARY
SAN GABRIEL AREA 1
INITIAL REMEDIAL MEASURES
September 1987
SUMMARY
Large areas of the San Gabriel groundwater basin, Los Angeles
County, California, have been found to be contaminated with
chlorinated hydrocarbons. San Gabriel Area 1, a plume of groundwater
contamination located primarily underneath the city of El Monte,
was included on EPA's final National Priorities List in May 1984.
In 1980, the State of California began an extensive well water
testing program in the San Gabriel basin which found numerous
wells contaminated with trichloroethylene (TCE), tetrachloroethylene
(PCE), and other chlorinated hydrocarbons. The California Department
of Health Services (DOHS) directed public water companies in the
area to periodically test their wells. State Action Levels for
TCE and PCE were set at 5 and 4 parts per billion (ppb), respectively,
based on the Environmental Protection Agency's (EPA) Suggested No
Adverse Response Level (SNARL). If alternative methods of reducing
PCE and TCE concentrations below the Action Levels (such as
blending waters from different wells) are not effective, wells
must be removed from service. In 1983, when EPA became involved
in addressing this problem, there were three mutual water companies—
Richwood, Rurban Homes, and Hemlock—that had no alternative
water supply and had been providing their customers with water
that is contaminated with PCE at concentrations above the DOHS
Action Level.
In May 1963, a management committee comprised of EPA, various
state and local agencies, and representatives of various water
companies and public interest organizations was established with
California DOHS as its chair. The objectives of this committee
are: 1) to find a solution for the three mutual water companies
that have a well contamination problem and have no alternative
water supply; 2) to identify and control any TCE/PCE sources; and
3) to develop an overall strategy for management of the plume
areas.
-------
-2-
To address this first objective, EPA directed its contractor/
CH2M Hill to evaluate alternative initial remedial measures (IRM)
to solve the mutuals' water contamination problems during the
interim period before a final long-term solution to groundwater
contamination in the San Gabriel basin is implemented. This
evaluation was summarized in a Focused Feasibility Study dated
December 6, 1983.
On May 11, 1984, after a formal public comment period/ EPA
Region 9's Regional Administrator signed a Record of Decision
(ROD) selecting air-stripping treatment as the most cost-effective
initial remedial measure (IRM) to provide three small mutual
water companies in El Monte with a source of uncontaminated
water. During the design phase of the IRM/ it became apparent
that the cost to construct and operate air-stripping systems
would be much higher than estimated in the Focused Feasibility
Study (FFS) and the ROD/ due to the severe site constraints
associated with designing and constructing treatment systems for
the mutuals. In addition/ to design an air-stripping system that
the mutuals could operate reliably/ and which would not result in
adverse impacts on the neighboring community/ would require the
addition of a 60/000 gallon storage reservoir to the treatment
system at each mutuals1 well site.
As a result of these findings/ revised cost estimates have
been developed for all of the alternatives considered in the
ROD. Based on these revised cost estimates/ and on the other
relative advantages and disadvantages (non-cost factors) of the
feasible alternatives/ EPA has determined that carbon adsorption
treatment is now the cost-effective alternative.
DISCUSSION
I. Background
On December 6, 1983, EPA's zone contractor/ CH2M Hill
completed a Focused Feasibility Study (CH2M Hill/ 1983) which
evaluated various alternative initial remedial measures (IRM)
which would provide three small mutual water companies in El
Monte with a source of uncontaminated water. The three companies—
Richwood, Rurban Homes/ and Hemlock Mutual Water Companies—had
wells contaminated with tetrachloroethylene (also known as
perchloroethylene or PCE). While other water companies in San
Gabriel Areas 1-4 also have contaminated wells/ only these three
mutuals were unable to provide water that meets the EPA Suggested
No Adverse Response Levels (SNARL) for a 10"° cancer risk level for
PCE and trichloroethylene (TCE). Larger water companies have taken
interim actions such as shutting down contaminated wells or
blending water from clean and contaminated wells to meet the SNARL
level. These options were not available to the three mutuals.
-------
-3-
The Focused Feasibility Study (FFS) identified several
feasible alternatives to solve the mutuals' problems. After a
formal public comment period and a public meeting to which all
members of the mutuals were invited, Region 9's Regional
Administrator signed a Record of Decision on May 11, 1984 selecting
air-stripping treatment as the cost-effective IRM for San Gabriel
Area 1 (U.S. EPA, 1984). Two alternatives that were technically
feasible and lower in cost than air-stripping were not selected
as the cost-effective IRM due to institutional problems. The
lowest cost alternative, under which the mutuals would obtain
water from a nearby water company while leasing their water
rights, was not selected because no nearby water company was
identified which would agree to provide water under such an
arrangement. The next lowest cost alternative was for the mutuals
to dissolve as independent water companies and join a nearby
water company. This alternative was not selected after the
membership of each mutual voted not to dissolve.
After the Record of Decision was signed, EPA issued a work
assignment to its contractor, Cfc^M Hill, to design air-stripping
treatment systems for the Richwood and Rurban Homes Mutual Water
Companies. The third mutual, Hemlock, declined to have an air-
stripping system provided as an IRM and has instead purchased and
installed its own carbon adsorption system. In June of 1984, the
design team from CH2M Hill visited the mutuals1 well sites to
obtain background information on the present water systems'
operating characteristics and to obtain water samples for full
organic priority pollutant analysis. The purpose of the water
analyses was to confirm that the only contaminants present were
volatile organics which could be treated with an air-stripping
system. The results of these analyses confirmed that PCE was the
only contaminant present in the mutuals' well water at levels of
concern.
After the initial site visit, CH2M Hill recommended the
preparation of a Pre-Design Study of air-stripping systems for
the Richwood and Rurban Homes mutuals. The site visit had
identified several severe constraints that would be imposed on the
system design due to the limited site area, high peak water flows
in the systems, close proximity to neighbors at the well sites,
and the need~to design a system which the mutuals could operate
reliably (since the California Department of Health Services
(DBS) at that time planned to require the mutuals to be responsible
for system operation and maintenance). The purpose of the Pre-Oesign
Study was to investigate different configurations of air-stripping
systems to determine the most cost-effective and reliable
configuration before proceeding with the final system design.
EPA authorized CH2M Hill to begin this study in July 1984.
II. The Pre-Design Study
During the Pre-Design Study, CH2M Hill identified and focused
on five major considerations in the development of an air-stripping
system design:
-------
-4-
1) Peak Factor. For both mutuals, there is a constant
cycling of water flow in the system from zero to as high as 880
gallons per minute. These flow rates are caused by the cycling
on and off of the mutuals' wells during operation. The reason
for this constant cycling of the wells is that the mutuals lack
the reservoir capacity that would be available in a standard
waterworks system. Both mutuals have only small pressure tanks
at the well sites which feed directly into the distribution
system. When the pressure in the system drops below a certain set
value/ the pumps turn on long enough to raise the pressure back
above that value.
Since the flow rate of the system is an important design
criterion/ a flow rate study of the mutuals' systems was-conducted.
Multiple time-volume measurements were used to determine the well
pumping rates for Richwood and Rurban Homes. Average flow rates
were determined by estimating the length of time each pump operated
during the month and using the measured pumping rate. The results
of the flow rate study showed that the average flow rates of the
mutuals1 water systems were underestimated during the FFS, by as
much as 79% in the case of Richwood's system. The average flow
rates used in the FFS and the revised estimates for Richwood and
Rurban Homes are summarized in the table below. These findings
are especially significant since the flow rate can have an importar*
effect on the design of alternative water supply systems/ as well
as on their associated capital and operating costs.
Water System Average Flow Rates
Focused Revised
Mutual Feasibility Study Estimate
Water Estimate (Pre-Oesign Study) Percent
Company (gallons/minute) (gallons/mlnute) Difference
Rurban Homes 135 210 +56%
Richwood 95 170 +79%
2) Operational Simplicity. The mutuals are presently
certified to operate their existing water systems. Since the
present systems are not complex/ they do not employ highly trained
individuals as system operators. Thus/ operational simplicity is
desirable for the treatment systems in order to reduce the impact
on the mutuals' operation of their waterworks system/ and to
ensure reliable operation of the treatment system.
3) Limited Area Available. Both mutuals have limited area
available at their well sites for construction of a treatment
system. This imposes a serious constraint for facility construction
especially for the Richwood mutual which has the smaller well site.
Special site preparation and construction procedures will be
required/ affecting the capital cost of the system.
-------
4) Close Proximity of Neighbors. The sites are very close
to neighboring residences. Thus, the community will be sensitive
to any noise produced by the treatment systems, especially at night.
5.) Cost. It became clear in the early stages of the Pre-
Design Study that the combination of site constraints would lead
to increased costs in the design and construction of air-stripping
systems for the mutuals, well above those estimated in the FFS.
To enable EPA to compare the costs of different air-stripping
system configurations, both capital and operating costs were
developed for all the treatment system configurations evaluated.
Hill identified two potential air-stripping treatment
system configurations for the mutuals. The primary difference
between the configurations was whether or not a 60,000 gallon
storage reservoir was installed in addition to the air-stripping
towers. Also/ when it became apparent that the cost of. air-stripping
treatment was going to be much higher than previously estimated,
CH2M Hill also revised the conceptual design and costs for carbon
adsorption treatment systems for the mutuals. Carbon adsorption
was reconsidered since it was identified in the FFS as the next
most cost-effective feasible alternative after air-stripping,
and also because it has several other advantages. The three
treatment system configurations evaluated during the Pre-Design
study are briefly described as follows/ along with a discussion of
their relative advantages and disadvantages, as identified during
the Pre-Oesign Study (CH2M Hill, 1984). The revised cost estimates
for the treatment system configurations will be discussed in a
later section.
1) Air-stripping without a storage reservoir. This
alternative is the system envisioned in the feasibility study.
Water would be pumped directly from the well to two parallel
air-stripping towers, and then pumped to the existing pressure
tanks at the site before distribution to the mutuals' members.
A major problem with this alternative is that the well pumps
presently cycle on and off continuously every few minutes
24 hours a day. Similar cycling of the air-stripping system may
create potential problems concerning system reliability. The
continuous cycling of the air-stripping system may cause excessive
equipment wear. In addition, operation of this system would
require the a»e of a sophisticated microprocessor control system.
This is necessary to control the constant cycling on and off this
system would require. Operation of a complex control system is
probably beyond the capability of the mutuals present staff.
This is a serious problem/ since DOHS planned to negotiate a
letter of understanding or contract with the mutuals under which
the mutuals would be responsible for ongoing operation and
maintenance of the air-stripping system. Thus, the reliability
of the system may be in question if this treatment system
configuration is implemented.
There are several other disadvantages associated with this
alternative involving potential adverse impacts on the community
-------
-6-
surrounding the well sites. This air-stripping system configura, jn
would require essentially 24-hour operation with the system
constantly cycling on and off. The constant cycling may cause I
electrical surges in the neighborhood. In addition, continuous
operation may create a noise problem/ a particularly severe °
disadvantage given the fact that the sites are located in residential
neighborhoods within 200 feet of nearby houses. Operation of an
air-stripping system will increase the noise levels at the well
sites due to the air blowers installed at the bottom of each
air-stripping tower. Although noise barriers would be included
in the system design, it may not be possible to completely mitigate
the impact of increased noise during night-time operations.
Finally/ another disadvantage to this configuration is that the
system would require monthly shutdown of the towers for an hour
or two fo'r disinfection. While this can be done for one tower at
a time/ it would have to be done at periods of low demand or else
water use would have to be restricted during this activity. A
drainage system would have to be installed to dispose of
effluent during this system flushing.
2) Air-stripping with a storage reservoir. This system
would have the same configuration as the first alternative
except that the system would also have a 60/000 gallon storage
reservoir. This would be a below-grade or partially below
grade concrete reservoir/ with the air-stripping towers
installed directly above the reservoir. This would allow the air-
stripping system to operate continuously for longer periods of
time and would reduce the potential reliability problems. Less
frequent cycling of the system would reduce equipment wear.
This configuration would also not require the sophisticated control
system of the first alternative/ because the wells could pump
continuously for longer periods of time while filling up the
reservoir. This treatment system configuration would require
much less change in the mutuals' current system operation than
the other air-stripping configuration/ and therefore/ operation
of the system by the mutuals should be more reliable.
In addition to the advantages in terms of reliability/ this
air-stripping system configuration has several other advantages.
The reservoir would store enough water so that in most cases/ the
system wouldrnot have to run at night/ thereby solving the
potential noise problem. In addition/ more continuous operation
of the system will reduce the frequency of power surges in the
neighborhood. Another advantage of this configuration is that/
because of the reservoir/ no restrictions on water use would be
required during maintenance shutdowns of the towers.
While this alternative would provide much more reliability and
ease of operation than the first alternative/ it has the disadvantage
of approximately 50% higher capital costs/ and greater land
requirements. The latter disadvantage is particularly significant
for Richwood's situation since their well site has very limited
area available for construction. Additional contingency was
-------
-7-
added to the cost estimate for constructing this system configuration
at Richwood1s well site due to this complicating factor.
There are also two disadvantages common to both of the air-
stripping system configurations. First/ heavy construction
equipment would be required to install these systems and both
.sites have limited area. At Richwood/ and possibly at Rurban
Homes/ it would require that easements from neighboring land-owners
be obtained that allow this equipment to park and operate on their
land. Second/ for any air-stripping configuration there is a
potential community concern with air emissions from the systems.
In this case/ the estimated emissions are quite low and should
not create any potential public health or environmental problem.
Before construction of air-stripping systems/ EPA planned to
follow the South Coast Air Quality Management District's review
process for air-stripping towers. This process includes modeling
the estimated emissions to determine potential community exposure/
followed by completion of a health risk assessment by OHS's
Epidemiology Studies section.
3} Carbon adsorption. Carbon adsorption has many operational
advantages over air-stripping. A carbon system could be placed
within the mutuals' existing water systems without changing
the mutuals' current system of operating their wells. The
system would require no control system beyond that which is
already in the mutuals1 systems. The system would be easy to
operate and maintain. The only required maintenance would be
that the carbon be changed periodically (approximately once
or twice a year). Activated carbon supply companies could
be contracted with to recharge the carbon vessels and haul
away the spent carbon. Except for this activity/ the mutuals
could operate exactly the same as they do now. A carbon
system is smaller in size than an air-stripping system/
thereby making it easier to design the system to fit in the
small space available on-site. In addition/ it would not
require as extensive construction activity as would be required
to install an air-stripping system. At the Richwood site/ it may
be possible to install separate carbon systems at each well site/
eliminating the need for a connecting pipe between the sites (one
well site i* obviously too small for an air-stripping tower/
thereby necessitating the connecting pipe for those alternatives).
Another factor which could affect the mutuals1 members satisfaction
with an EPA-installed treatment system is the resulting taste of
the water. An air-stripping system will remove carbon dioxide
from the water which would affect the water's taste. However/ a
carbon system should have no affect on the taste of the mutuals'
water (except for the effect of chlorination/ which is common to
both air-stripping and carbon adsorption). Carbon adsorption
also offers an advantage regarding the protection of public
health in that it is not designed specifically to remove PCE. A
carbon system would remove a wide variety of organic as well as
inorganic contaminants. On the other hand/ the air-stripping
tower would be designed to remove a specific concentration of
-------
-8-
PCE. While other volatile contaminants would be removed/ the
removal efficiency would depend on the relative volatility of the
contaminant. As an example/ TCE is relatively less volatile than
PCE. Finally/ one last advantage of a carbon system is that
there are no air emissions produced/ thus eliminating air emissions-
as a potential cause for community concern.
The primary disadvantage of the carbon adsorption alternative
is that the operation costs are over three times higher than
those for air-stripping. This was considered a major disadvantage
since DBS had developed a policy regarding operation and maintenance
(O&M) requirements which can be summarized as "When a remedial
action directly benefits a viable public or private organization
that is willing and able to provide for future maintenance of
such an action/ it is DHS's intention to obtain commitment for
this maintenance from this organization.* In this situation/
DHS had taken the position that the mutuals should pay for
ongoing O&M. Unfortunately/ the high estimated operating cost
of the carbon adsorption alternative would cause an increase in
the mutuals' members average monthly water bill of over 400%--
from approximately $8 to as high as $41 per month—an increase
in cost which the mutuals members would probably not agree to.
In addition/ if contaminant levels rise to much higher levels/
O&M costs would go up as more carbon is used. O&M costs for an
air-stripper are generally constant over a range of contaminant
levels (This assumes/ of course/ that the air-stripping system is
designed to handle the increased levels of contamination.).
Evaluation of an Upgrade to Hemlock's Existing System.
When EPA became aware that the cost of carbon adsorption
systems for Richwood and Rurban Homes would be comparable to the
cost of air-stripping systems/ a reevaluation of Hemlock's situation
was included in the Pre-Oesign Study. Hemlock had declined to
participate in the IRM project when air-stripping was selected by
EPA as the most cost-effective alternative. Instead/ they had
purchased and installed a carbon adsorption system to treat their
drinking water. While pilot tests had shown that their system
would adequately treat the contaminated water from their wells/
their system was not designed with the same design standards
proposed by EPA for Richwood and Rurban Homes in the Pre-Design
Study. In addition/ OHS required that Hemlock install a flow
restrictor on their water system to ensure adequate treatment of
their well water. The flow restrictor limited the rate at which
well water could be treated by the carbon adsorption system and
could possibly cause problems with low water pressure in the
systems at times of peak water use. Therefore/ as part of the
Pre-Oesign Study/ EPA directed CH2M Hill to evaluate the feasibility
and costs of improving Hemlock's treatment system to meet the
design standards used to design carbon adsorption systems for the
other mutuals. This evaluation proved that installing an upgrade
to Hemlock's system was probably cost-effective in comparison to
-------
-9-
air-stripping, since the design of an air-stripping system for
Hemlock would be affected by the same constraints associated with
Richwodd and Rurban Homes' systems.
III. Activities Subsequent to Completion of the Pre-Design Study.
Consultation with DBS
When the Pre-Design Study was received by EPA in October
1984, discussions were held with OHS to determine which alternative
they recommended and if the DHS policy concerning provision of
O&M costs for the IRM had changed. In a letter dated October 24,
1984, OHS made the following statements:
1) All of the alternatives examined in the Pre-Design study
appeared to have similar cost-effectiveness when considering the
combined technical, social, and cost aspects of each. They
supported the idea of presenting the results of the Pre-Design
Study to the mutuals and obtaining their preference for the IRM.
2) Since EPA (in the State Superfund Contract with OHS) is
requiring the State to assure O&M for the design life of the
system (20 years), OHS feels that the cost analysis should
examine 20-year present worth costs, as well (instead of the
5-year time period used in the Pre-Design Study). Based on its
low operating cost, it appears that air-stripping is still the
preferred alternative.
3) DHS has received letters of intent from the mutuals
regarding their commitment to provide funds for long-term O&M.
Community Relations Activities
After CH2M Hill's site visit in June 1984, the mutuals were
informed by EPA that a Pre-Design Study would be conducted. Once
the study and the subsequent consultations with DOHS were completed,
the Pre-Oesign Study was sent to the Board of Directors of the
Richwood and Rurban Homes mutuals for their review. A meeting
between EPA and the Boards of the mutuals was held in El Monte
on November 7, 1984. At this meeting, the results of the Pre-Design
Study were presented to the mutuals1 Boards along with estimates
of the annual operating costs, for which the mutuals would be
responsible for providing funds, under each alternative. EPA
requested guidance from the mutuals' boardmembers as to whether
they thought another full meeting of the mutuals1 shareholders
should be held given the major change in estimated costs for.the
alternatives.
The boardmembers of the Rurban Homes mutual decided at this
meeting that a meeting for their shareholders was not necessary.
In addition, based on the information provided by EPA and in the
Pre-Design Report, they selected the air-stripping system
-------
-10-
configuration that included the storage reservoir as their preferred
alternative. They specifically stated that even though the
carbon adsorption alternative had several advantages/ the operatingt
costs were 3*0 high that the mutual *s shareholders would never
vote to accept them. Since the shareholders had previously voted
to accept the air-stripping alternative/ the boardmembers felt
that another shareholders vote was not necessary.
Not all of the boardraembers from the Richwood mutual were
available to attend the November meeting with EPA. Therefore/
the boardmembers informed EPA that they would call a meeting of
the full board at a later date to discuss the alternatives and would
provide EPA with the results of that meeting. Richwood's president/
Mel Huber, informed EPA in December 1985 that Richwood's boardmembers
had also decided that the air-stripping configuration with the
60/000 gallon storage reservoir was their preferred IRN alternative/
and that a full shareholder vote was not necessary to implement
this alternative since they had previously approved air-stripping
treatment. As with Rurban Homes/ Richwood's boardmembers recognized
the advantages of the carbon adsorption alternative/ but determined
that the mutuals1 members would not approve it due to its high
operating costs.
In November/ 1984/ the Pre-Design Study was provided to the
board of directors of Hemlock Mutual Mater Company. EPA notified
Hemlock's board of directors that an upgrade to their existing
treatment system could potentially be included as part of the IRM
if Hemlock agreed to pay the operating costs associated with the
improved system. Hemlock notified EPA that it still did not wish
to participate in the IRM project.
Conceptual Design of Air-Stripping Systems
Based on an evaluation of the results of the Pre-Oesign
Study/ EPA's consultations with DHS, and community relations
activities involving the three mutuals/ EPA prepared a revised
cost-effectiveness analysis of the IRM alternatives that was
approved in August 1985 (U.S. EPA/ 1985). EPA determined that
the air-stripping system configuration that did not include the
in-ground storage reservoir was not cost-effective due primarily
to potential.problems with system reliability. An additional
consideration was the potential adverse impacts on the surrounding
community/ such as noise associated with 24-hour operation in a
residential neighborhood. The cost of including a storage reservoir
in the air-stripping system/ however/ made the total 5-year costs
for air-stripping and carbon adsorption virtually equal. [Five
years was used as the basis for comparison/ because the proposed
action was being taken as an initial remedial measure and its
objective was to provide a supply of uncontaminated water to the
mutuals in the interim before a long-term remedial action is
implemented/ It was expected to take approximately 5 years before
a long-term remedial action is implemented.] Therefore/ either
-------
-11-
treatment system alternative appeared to be potentially cost-
effective/ although carbon adsorption had several non-cost advantages
over the air-stripping alternative. The only significant difference
in cost is that air-stripping has a much higher capital cost than
carbon adsorption/ but significantly lower operation & maintenance
(OftM) costs. This fact, however/ had a large effect on the
institutional feasibility of implementing the carbon adsorption
alternative/ since at that time, DHS planned to require the
mutuals to pay for long-term O&M costs. This would have led to
an increase in the average monthly water bill of the mutuals'
members by over 400% which was not considered acceptable to
the mutuals and therefore/ not institutionally feasible. Based
primarily on the institutional feasibility issue/ EPA decided
that the air-stripping alternative/ which now included the
installation of an in-ground storage reservoir/ was still the
cost-effective IRM alternative for Richwood and Rurban Homes.
EPA directed its contractor/ CH2M Hill/ to prepare detailed
conceptual designs for air-stripping systems (including storage
reservoirs) for Richwood and Rurban Homes and to prepare South
Coast Air Quality Management District (SCAQMD) permit applications
for the two mutuals. The conceptual designs were completed and
the mutuals submitted permit applications to SCAQMD in September
1985 (CH2M Hill/ 1985a, 1985b). The detailed conceptual designs
did not contain any major differences from the preliminary conceptual
designs of the airstripping systems included in the Pre-Design
Study.
During the preparation of the detailed conceptual designs for
the air-stripping systems/ the level of contamination in Richwood's
wells started to rise and approached 100 ppb of PCE, 20 times
higher than the SNARL level of 4 ppb. Since this water was being
delivered to customers for drinking and startup of the air-
stripping system was at least 8 months away/ DHS used state funds
to pay for an emergency temporary pipeline connection from Richwood
to the San Gabriel Valley Water Company. San Gabriel Valley
Water Company agreed to provide water to Richwood until the IRM
was implemented. The temporary connection was in place in early
1986.
Senate Bill 1063
In August of 1985/ the California State Assembly began
considering Senate Bill 1063 (SB 1063) that would authorize State
funding for design and construction of carbon treatment systems
for Richwood and Rurban Homes/ as well as an upgrade to Hemlock's
existing carbon adsorption system. The most significant feature of
SB 1063 was that it directed DHS to pay for O&M for the carbon
adsorption systems for 20 years (the design life of the treatment
systems). The bill was passed by the legislature and became law
in October 1985. In February 1986/ DHS informed EPA that it was
prepared to implement the provisions of SB 1063/ including the
payment for 04M on the three carbon adsorption systems. In
-------
-12-
addition/ OHS has decided that it will pay for OSM of Hemlock's
existing carbon adsorption system, whether or not the proposed
upgrade to their system is installed.
Conceptual Design of Carbon Adsorption Systems
Since EPA's decision in August 1985 regarding the continued
cost-effectiveness of implementing the air-stripping alternative
was based primarily on the lack of institutional feasibility of
the carbon adsorption alternative (due to the inability of the
mutuals to pay the high cost of O&M of carbon adsorption systems)/
the passage of SB 1063 allows EPA to reconsider its decision.
In anticipation of a formal reconsideration of the May 1984 Record
of Decision/ EPA directed its contractor/ CH2M Hill/ to prepare
detailed conceptual designs of the carbon adsorption alternative for
the three mutuals. In addition/ updated cost estimates for the
air-stripping and carbon adsorption alternatives were requested.
Preparing the carbon adsorption conceptual designs was to occur in
parallel with the SCAQMD's modeling of estimated air emissions
for the air-stripping designs as part of SCAQMD's permit approval
process. This would bring the design of air-stripping and carbon
adsorption systems to an equal point/ so that the IRM project
could be expeditiously completed regardless of which alternative
EPA chose to go forward with.
In preparing detailed conceptual designs of carbon adsorption
systems for the three mutuals, several significant changes were
made from the preliminary conceptual designs for carbon adsorption
systems that were included in the Pre-Design Study. The major
changes are summarized here for the three mutuals' systems:
1) Richwood and Rurban Homes. The detailed conceptual
designs are based on the assumption used during the Pre-
Design Study that an empty-bed-contact-time (EBCT) of 10
minutes at peak system flow will be sufficient to achieve
suitable levels of contaminant removal (EBCT » carbon bed
volume / peak, system flow rate).
A major change in the detailed conceptual design/
however/ is that it is planned to use two carbon vessels in
a series configuration (i.e./ the treated effluent from the
first carbon bed will then be treated by the second carbon
bed before distribution to the mutuals' distribution system)
rather than the parallel configuration (i.e./ the flow
being split between the two carbon beds and each stream is
treated by only one carbon bed) contemplated during the
Pre-Design Study. The series configuration offers the
advantages of a greater safety factor since at "breakthrough*
-------
-13-
(the time at which a noticeable increase in the contaminant
concentration in the effluent occurs) for the first carbon
bed/ the second bed safeguards against the passing of
contaminants into the distribution system. This in turn
allows less frequent sampling and analysis of the system,
and therefore, lower degree of required operator attention
and lower operating costs. In addition/ a series
configuration allows flexibility in optimizing the carbon
usage rate of the system, which is the most significant
factor in determining the system's operating cost.
A closer analysis of the requirements for designing
adequate carbon systems for the mutuals also led to the
identification of two additional system components: booster
pumps and dedicated backwash systems. Estimates of the
pressure head loss that would occur through the carbon beds
required the addition of booster pumps to the conceptual
design for the carbon adsorption systems. A primary booster
pump would be used to increase the water pressure before
carbon treatment to maintain the current discharge pressures
to the mutuals' distribution systems. A secondary booster
pump would also be installed to provide standby booster
capacity. It was considered prudent to include booster
pumps in the design because the actual head and capacity of
the mutuals' well pumps is unknown. In addition, to reduce
headless and to improve system performance, dedicated
backwash systems would be installed. The backwash system
would consist of a dedicated pump and a backwash storage
reservoir (an in-ground reservoir would be used for Richwood's
system, while an above-ground steel tank would be used for
Rurban Homes). Approximately once per month, the water
from the backwash storage reservoir would be pumped through
the carbon vessels to expand the carbon bed. The wastewater
produced during backwash of the system would be piped to a
drainage sump that connects to the waste system and would
flow to the storm drain system for disposal.
The addition of booster pumps to the carbon adsorption
system conceptual design reduced the relative advantages
that the Pre-Design Study determined carbon adsorption had
as compared to air-stripping. For example, the addition of
booster; pumps will lead to the carbon adsorption system
having a control system as complex as the air-stripping
alternative without reservoir storage. The design of a
simple treatment system to ensure "system reliability" is
not as crucial for the carbon adsorption system, however,
since DHS would operate the carbon adsorption system under
SB 1063. The additional power load of the booster pumps
will also increase the possibility that the carbon adsorption
system could cause electrical power surges in the neighborhood
as the wells cycle on and off. The power load for the
carbon adsorption system, however, would be approximately
-------
-14-
half that of the air-stripping system, so that in a relative
comparicon, air-stripping may cause more power surges. It
cannot be determined whether the added power load of the
carbon adsorption or airstripping will definitely lead to
electrical surges without a detailed evaluation based on
information from the local power company and an analysis of
the motor starting characteristics of the existing and
proposed equipment. An air-stripping system, however,
would have a higher probability of causing such surges due
to the greater increase in cycling power load. The
addition of the booster pumps will also add additional
noise to the carbon adsorption syste, although again this
would be relatively less of a problem than for air-stripping
since the air-stripping system would have air blowers as
well as booster pumps operating.
2) Hemlock. The conceptual design of an upgrade to
Hemlock's existing carbon adsorption system was based on
meeting the same design criteria as the conceptual designs
for Richwood and Rurban Homes — the major design criterion
being achieving a 10 minute EBCT at peak flow. The peak
flow of Hemlock's system was assumed to be 500 gpm, the sum
of the nominal capacities of Hemlock's two well pumps.
Hemlock's current carbon adsorption system is sized to
treat a peak flow of 360 gpm with an EBCT of 5 minutes.
Although limited pilot testing by Hemlock has shown that a
5-minute EBCT is sufficient to treat the current level of
contamination of Hemlock's wells, the system does not have
the same normal safety factor built into its design as in
the conceptual designs for Richwood and Rurban Homes. This
is a concern since higher levels of contamination occur in
other nearby wells and have occurred in Hemlock's wells in
the past. Also, Hemlock operates its system with a flow
restrictor to ensure that the peak flow is not greater than
360 gpm, which would lead to an EBCT of less than 5 minutes.
This has led to some problems with maintaining adequate
pressure in Hemlock's distribution sytem. Although a peak
flow of 500 gpm was assumed during the conceptual design
of an upgrade to Hemlock's existing treatment system, a
more accurate estimate of Hemlock's peak flow would have to
be obtained before the final design of an upgrade to their
existing treatment system could be prepared. In addition,
for the purposes of the conceptual design and cost estimates,
a more recent estimate for Hemlock's average flow of 150
gpm was used.
EPA's contractor, CH2*f Hill, evaluated 2 major sub-
alternative methods of upgrading Hemlock's existing carbon
adsorption system: 1) dedicating Hemlock's existing system
(with minor modifications) to treating the discharge from
Hemlock's North well and installing a separate system to
treat the discharge from the South well; and 2) dismantling
-------
-15-
the existing carbon adsorption system and installing a new
system sized to treat the entire 500 gpm peak flow. The
second subalternative conceptual design has the option of
including a dedicated backwash storage and pumping system
(as in the Richwood and Rurban Homes conceptual designs) or
operating as Hemlock's current system operates with the
effluent from one of the carbon vessels being used to
backwash the other vessel. In general/ the first subalternative
has the advantage of lower initial capital cost, however,
the second subalternative offers greater ease of system operation
and lower O&M costs. The relative advantages and disadvantages
of the two system upgrade subalternatives are discussed in more
detail in the conceptual design report, Evaluation of
Alternatives for Hemlock Mutual Water Company Activated
Carbon System Expansion, June 19, 1986 (CHjM Hill, 1986e).
The specific alternative method of upgrading Hemlock's
existing carbon adsorption treatment system to be used would
be determined during remedial design of the IRN.
The conceptual designs and cost estimates for carbon adsorption
systems for Richwood and Rurban Homes, and for alternative methods
of upgrading Hemlock's existing carbon adsorption systems were
completed in June 1986 (CH2M Hill, 1986c, 1986d, 1986e). In
addition, the cost estimates for the air-stripping alternative were
also updated in June 1986 (CH2M Hill, 19865).
-------
-16-
IV. Cost Revisions
As discussed previously/ CH2M Hill had developed revised
cost estimates during the Pre-Design Study for air-stripping and
carbon adsorption treatment systems for the Richwood and Rurban
Homes Mutual Water companies. For air-stripping systems/ costs
were developed for two distinct treatment system configurations—
with and without a storage reservoir. The cost estimates for
carbon adsorption and for the air-stripping configuration with
the storage reservoir for Richwood and Rurban Homes/ and for
alternative methods of upgrading Hemlock's existing carbon adsorption
system were updated in June 1986 after detailed conceptual designs
were prepared. An updated cost estimate for the air-stripping
configuration that doesn't include a storage reservoir and air-
stripping alternative cost estimates for Hemlock were derived
from June 1986 cost estimates for the air-stripping configuration
that included a storage reservoir prepared for Richwood and Rurban
Homes as explained in the following section.
In addition/ since the flow rate study conducted as part of
the Pre-Design Study developed estimated flow rates for Richwood
and Rurban Homes that are significantly higher than the estimated
flow rates used in the FFS, cost estimates for the other potentially
feasible IRM alternatives have been revised based on the most
recent flow rate estimates for those mutuals. A more recent
estimate of Hemlock's average flow rate has also been used in
revising the cost estimates for the IRM alternatives.
Table 1 summarizes the revised cost estimates for the IRM
alternatives. Table 1 and the following discussion excludes two
alternatives which were identified in the FFS and the Record of
Decision: 1) mutuals obtain water from a nearby water purveyor
while maintaining their water rights; and 2) mutuals obtain water
from a nearby water purveyor while leasing their water rights to
the purveyor. These two alternatives have been deleted from
further consideration at this time since no nearby water purveyor
has been identified that would agree to provide water to the
mutuals under either of these arrangements/ except in the case of
Richwood where San Gabriel Valley water Company agreed to provide
water on an emergency temporary basis until the IRM could be
implemented.
The costs summarized in Table 1 have been calculated for
each of the alternatives based on the following assumptions:
- 5 year operation (since it is estimated that a final remedial
action will be implemented by that time)/
- 10% discount factor in the present worth analysis/ and
- revised estimates of well flow rates as determined during the
Pre-Design Study/ as well as a more recent estimate of Hemlock's
system's average flow rate.
An evaluation of the current estimated costs in comparison
with the December 1983 costs estimated in the FFS is presented in
the following pages.
-------
ALTERNATIVE I; Air-Stripping Treatment
December 1983 Estimate; Air-stripping treatment system capital
and operating cost estimates are taken from the FFS prepared by
CH2M Hill (CH2M Hill, 1983). Operating costs do not include the
cost of periodic water sample analyses to ensure successful removal
of contaminants by the treatment system.
June 1986 Estimate; Capital and operating costs for the air-
stripping system configuration which includes a storage
reservoir for Richwood and Rurban Homes were developed by CH2M
Hill (CH2M Hill, 1986b) based on the detailed conceptual designs
completed in September 1985 (Cf^M Hill, 1985a, 198Sb). A higher
capital cost allowance for equipment installation and reservoir
construction has been included in the cost estimates for the
Richwood mutual to allow for additional construction costs associated
with installing a treatment system in such a small well site
(Richwood's well site is much smaller than Rurban Homes). For
Hemlock, the cost estimate from Richwood has been used with minor
modifications. The cost estimate for Richwood is assumed to be
fairly accurate for Hemlock for several reasons. First, both
systems operate in the same manner with two wells, a hydropneumatic
tank, and a constant cycling on and off of the wells to maintain
system pressure. The average system flow rate of Hemlock is 150
gpra as compared to 170 gpm for Richwood and 210 for Rurban Homes.
Hemlock's well site is also very similar to Richwood's in that it
is very small and narrow. Therefore, the higher capital cost
allowances for equipment installation and reservoir construction
used in the Richwood cost estimate are expected to be more accurate
in Hemlock's situation than the lower cost allowances in the
Rurban Homes estimate. The cost of piping for Hemlock, however,
was based on the estimate for Rurban Homes ($20,000) rather than
Richwood ($50,000) because the additional cost for Richwood is
associated with installing a pipe connection from Richwood's
South well (located at a different well site from the where the
North well is and where the treatment system would be installed)
to the North well site.
Capital costs have also been revised to include an allowance
(15% of capital cost subtotal) for management services during
construction. This cost element was not identified as a separate
cost element during the FFS, but would be included in EPA's
implementation of the IRM. Operating costs have been revised to
include the cost of water sampling and analysis to monitor treatment
system performance and to add a contingency for operating costs.
These cost elements were also not included in the FFS cost
estimates.
Estimates for the air-stripping configuration that does not
include the storage reservoir were developed by subtracting the
cost of the storage reservoir from the cost estimates for the air-
stripping configuration that included the storage reservoir, and
subtracting the associated capital cost allowances for contingency;
engineering, legal and administrative fees; and management services
during construction.
-------
A. Air-Stripping; Rurban Homes Mutual Water Company.
December 1983
Estimate
CAPITAL COST
Towers with packing
Fans
Pumps
Piping
Chlorine System
Equipment
installation
Overflow Piping
Electrical
Soundproofed Bldg.
Mobilization &
site preparation
Subtotal without reservoir
Contingency
Engineering, legal, &
administrative fees
Management services
during construction
Total without reservoir
Subtotal without reservoir
60,000 gallon reservoir
Subtotal with reservoir
Contingency
Engineering, legal, &
administrative fees
Management services
during construction
Total with reservoir
ANNUAL OPERATING COST
Power
Maintenance
Sampling and Analysis cost
Subtotal—annual operating cost
contingency
Total annual operating cost
5-YEAR PRESENT WORTH
OPERATING COST
TOTAL 5-YEAR PRESENT WORTH COSTS
0 WITHOUT RESERVOIR
0 WITH RESERVOIR
$
$
$
$
§
$
49,000
8,000
16,000
4,000
10,000
61,000
*
*
*
*
148,000
44,000
23,000
***
215,000
**
**
**
**
**
**
**
*
*
***
17,400
***
17,400
66,000
June 1986
Estimate
$ 86,000
5,000
20,000
20,0001
12,5002
75,000
25,000
80,000
20,000
20,000
$ 363,000
109,000
54,000
54,000
$ 580,000 $ 365,000
$ 363,000
150,000
$ 513,000
154,000
77,000
77,000
$ 821,000
$ 8,500
10,000
12,000
$ 30,500
9,000
$ 39,500
$ 150,000
**
$ 22,100
$ 84,000
$ 281,000
**
$ 730,000 $ 449,000
$ 971,000 **
* This cost element was not broken out as a separate cost category
in the December 1983 FFS.
** This system configuration (with storage reservoir) was not
considered in the December 1983 FFS.
*** These cost elements were not included in the estimates of
annual operating costs in the December 1983 FFS.
1) This cost element in the June 1986 cost estimate combines the
cost of piping, valves, and instrumentation.
2) This cost element in the June 1986 .cost,. aiMinr 1 ^ v^:i ;^ =
-------
B. Air-Stripping: Richwood Mutual Water Company.
CAPITAL COST
Towers with packing
Fans
Pumps
Piping
Chlorine System
Equipment
installation
Overflow Piping
Electrical
Soundproofed Bldg.
Mobilization &
site preparation
Subtotal without reservoir
Contingency
Engineering, legal, &
administrative fees
Management services
during construction
Total without reservoir
Subtotal without reservoir
60,000 gallon reservoir
Subtotal with reservoir
Contingency
Engineering, legal, &
administrative fees
Management services
during construction
Total with reservoir
ANNUAL OPERATING COST
Power
Maintenance
Sampling and Analysis cost
Subtotal--annual operating cost {
contingency
Total annual operating cost J
5-YEAR PRESENT WORTH
OPERATING COST
TOTAL 5-YEAR PRESENT WORTH COSTS
0 WITHOUT RESERVOIR
0 WITH RESERVOIR
December 1983 June 1986
Estimate Estimate Difference
$
$
39,000
4,000
14,000
3,000
10,000
49,000
*
*
*
*
119,000
36,000
18,000
$ 86,000
5,000
20,000
50,000*
12,5002
125,000
25,000
80,000
20,000
20,000
$ 443,000.
133,000
66,000
***
"5 173,000
**
**
**
**
**
**
***
13,200
***
13,200
50,000
$ 223,000
**
66,000
9 708,000 $ 535,000
$ 443,000
200,000
$ 643,000
194,000
97,000
97,000
1,031,001)
**
$ 7,000
10,000
12,000
$ 29,000
8,700
§ 37,700 $ 24,500
$ 143,000
93,000
$ 851,000 $ 628,000
$ 1,174,000 **
* This cost element was not broken out as a separate cost category
in the December 1983 FFS.
** This system configuration (with storage reservoir) was not
considered in the December 1983 FFS*
*** These cost elements were not included in the estimates of
annual operating costs in the December 1983 FFS.
1) This cost element in the June 1986 cost estimate combines the
cost of piping/ valves, and instrumentation.
2) This cost element in the June 1986 cost esMn^.frs. zal;a ;s
-------
C. Air-Stripping: Hemlock Mutual Water Company.
CAPITAL COST
Towers with packing
Fans
Pumps
Piping
Chlorine System
Equipment
installation
Overflow Piping
Electrical
Soundproofed Bldg.
Mobilization &
site preparation
Subtotal without reservoir
Contingency
Engineering, legal, &
administrative fees
Management services
during construction
Total without reservoir
Subtotal without reservoir
60/000 gallon reservoir
Subtotal with reservoir
Contingency
Engineering, legal, &
administrative fees
Management services
during construction
Total with reservoir
ANNUAL OPERATING COST
Powe r
Maintenance
Sampling and Analysis cost
Subtotal—annual operating cost
contingency
Total annual operating cost
5-YEAR PRESENT WORTH
OPERATING COST
TOTAL 5-YEAR^PRESENT WORTH COSTS
0 WITHOUT RESERVOIR
- WITH RESERVOIR
December 1983
Estimate
$
$
24,000
4,000
14,000
3,000
10,000
39,000
*
*
94/000
28/000
15/000
June 1986
Estimate
$ 86/000
5,000
20,000
20,000*
12,5002
125,000
25,000
80,000
20,000
20,000
$ 413,000
124,000
62,000
***
5 137,000
**
**
**
**
**
**
v~f
62,000
9 661,000 $ 524,000
$ 413/000
200,000
$ 613,000
184,000
92/000 -
92/000
$ 981,000
**
*
*
$
***
§
10
/
800
$
***
$
$
10
41
i
i
800
000
$
$
7
1.0
12
29
8
37
143
/
/
/
,
/
,
/
000
000
000
000
700
700
000
$
$
26
102
,900
,000
$ 178,000
**
$ 804,000 $ 626,000
$ 1,124,000 **
* This cost element was not broken out as a separate cost category
in the December 1983 FFS.
** This system configuration (with storage reservoir) was not
considered in the December 1983 FFS.
*** These cost elements were not included in the estimates of
annual operating costs in the December 1983 FFS.
1) This cost element in the June 1986 cost estimate combines the
cost of piping/ valves, and instrumentation.
2) This cost element in the June 1986 coit •xtii^^ :-, no? •••--•-•
-------
D. Combined Cost of Air-Stripping for the Three Mutuals.
CAPITAL COST
Towers with packing
Fans
Pumps
Piping
Chlorine System
Equipment
installation
Overflow Piping
Electrical
Soundproofed Bldg.
Mobilization &
site preparation
Subtotal without reservoir
Contingency
Engineering/ legal/ &
administrative fees
Management services
during construction
Total without reservoir
Subtotal without reservoir
60/000 gallon reservoir
Subtotal with reservoir
Contingency
Engineering/ legal/ &
administrative fees
Management services
during construction
Total with reservoir
December 1983
Estimate
$ 112/000
16/000
44/000
10/000
30/000
149/000
*
*
*
*
I361/000
108/000
56,000
***
I525,000
**
**
**
**
**
**
ANNUAL OPERATING COST
Power
Maintenance
Sampling and Analysis cost ___
Subtotal—annual operating cost $
contingency __
Total annual operating cost $
5-YEAR PRESENT WORTH
OPERATING COST
TOTAL 5-YEAR PRESENT WORTH COSTS
0 WITHOUT RESERVOIR ,'
0 WITH RESERVOIR
*
*
***
41/400
***
41/400
§ 157/000
682/000
**
June 1986
Estimate Difference
$ 258/000
15/000
60/000
90/0001
37/5002
325/000
75/000
240/000
60/000
60,000
$ 1/219/000
366/000
182/000
182/000
$ 1/949/000 $ 1/424/000
$ 1,219/000
550/000
$ 1/769/000
532,000
266/000
266,000
2,333,000
**
$
$
$
§
22,500
30,000
36,000
88/500
26/400
114/900
436/000
$ 73/500
$ 279/000
$ 2/385/000 $ 1/703/000
$ 3/269/000 **
* This cost element was not broken out as a separate cost category
in the December 1983 FFS.
*.* This system configuration (with storage reservoir) was not
considered in the December 1983 FFS.
*** These cost elements were not included in the estimates of
annual operating costs in the December 1983 FFS.
1) This cost element in the June 1986 cost esfcimafo c^.ihi^:^ JP
-------
-22-
ALTERNATIVE 2: Carbon Adsorption Treatment
December 1983 Estimate: Carbon adsorption treatment system capital*"
and operating cost estimates are taken from the FFS prepared by
CH2M Hill (CH2M Hill/ 1983). Operating costs do not include the
cost of periodic water sample analyses to ensure successful removal
of contaminants by the treatment system.
June 1986 Estimate; Capital and operating costs for carbon
adsorption have been updated and are taken from the conceptual
designs for carbon adsorption systems prepared by EPA's contractor,
CH2M Hill in June 1986 (CH2M Hill, 1986c, 1986d, 1986e).
A much higher contingency allowance (50% as opposed to 10% in the
FFS) has been included in the estimates to reflect the potential
construction problems associated with installing treatment systems
in such small area well sites/ and the uncertainty in final system
design for the carbon adsorption alternative until pilot testing
is completed. This is higher than the contingency allowance used
for air-stripping (30%) because there are relatively less "unknowns"
for the cost of air-stripping than for the cost of carbon adsorption«,
In addition/ an allowance (15% of capital cost subtotal) has been
added for management services during construction. This cost
element was not included in the FFS.
A range of capital and operating costs for an upgrade to
Hemlock's existing carbon adsorption system is presented. The
range is based on the different subalternative methods of upgrading
Hemlock's existing system as outlined in the June 1986 CH2M Hill
conceptual design for Hemlock (CH2M Hill/ 1986e). The subtotals
and total cost figures presented do not equal the sum of the
ranges of the different cost elements because the different
subalternatives have higher costs for some cost categories/ but
lower costs in others. For each cost category/ the entire range
of cost estimates for the Hemlock subalternatives is presented.
The estimated operating costs for carbon adsorption have
been revised and are now an order of magnitude higher than the
estimate in the FFS. This large increase in estimated operating
costs is due to several factors. First/ the FFS cost estimates
were based on estimates of the carbon usage rate that were derived
from experimental data. The estimates in the Pre-Design Study
are based on more recent information regarding actual carbon
usage rates for existing carbon adsorption systems treating water
contaminated with low levels of organic compounds. These actual
carbon usage rates are much higher than the estimated usage rates
based on experimental data. The second factor contributing to
the increase in the operating cost estimate is the revised estimates
of the mutuals1 well flow rates. Since the operating cost of a
carbon adsorption system is approximately directly proportional
to the amount of water treated/ the higher flow estimates lead
to increased operating costs. Finally/ operating cost estimates
now include the cost of water sampling and analysis to monitor
: reatment system performance/ as well as a contingency allowance
.gain a high — 50% — allowance was used to reflect the uncertainty
actual system performance). These cost components were not
,1 eluded in the operating cost estimates in thi
-------
-23-
A. Carbon Adsorption: Rurban Homes Mutual Water Company.
December 1983 June 1986
CAPITAL COST
Equipment purchase
& installation; carbon
vessels with face
piping & internals
Chlorination system
Installation
Backwash storage
Pumps
Site piping, valves/
and instrumentation
Backwash discharge piping
Electrical
Mobilization & site
preparation
Subtotal
Contingency
Engineering/ legal &
administrative fees
Management services
during construction
Total
ANNUAL OPERATING COST
Activated Carbon
Maintenance
Sampling and analysis
Power
Subtotal
Contingency
Total annual operating cost
5-YEAR PRESENT NORTH
OPERATING COST
TOTAL 5-YEAR PRESENT
WORTH COSTS
$
$
$
§
$
$
$
§
$
Estimate
287/000-1
10/000
178/000
**
**
*
**
**
* ,
475,000
48/000
63/000 .
**
586/000
*
*
**
**
10/500
**
10/500
40/000
626/000
Estimate
$ 184/000
2/500
***
26/500
26/500
34/000
49/000
44/000
15/000
$ 381/500
191/000
57/300 -
57/300
$ 687/100
$ 49/500
7/600
12/000
2/000
$ 71,100
35/500
$ 106/600
$ 404/000
$ 1/091,100
Difference
$ 101,000
$ 96/100
$ 364/000
$ 465/100
**
This cost element was not broken out as a separate cost
category in the December 1983 FFS.
This cost element was not identified in the December 1983 FFS.
*** This cost element was not broken out as a separate cost
category in the June 1986 cost estimate.
1) This cost element includes the cost of the carbon vessels and
associated piping/ and the initial charge of activated carbon.
-------
-24-
B. Carbon Adsorption; Richwood Mutual Water Company.
December 1983 June 1986
CAPITAL COST
Equipment purchase
& installation; carbon
vessels with face
piping & internals
Chlorination system
Installation
Backwash storage
Pumps
Site piping, valves,
and instrumentation
Backwash discharge piping
Electrical
Mobilization & site
preparation
Subtotal
Contingency
Engineering, legal &
administrative fees
Management services
during construction
Total
ANNUAL OPERATING COST
Activated Carbon
Maintenance
Sampling and analysis
Power
Subtotal
Contingency
Total annual operating cost
5-YEAR PRESENT WORTH
OPERATING COST
TOTAL 5- YEAR PRESENT
NORTH COSTS
Estimate
$ 195, OOO1
$ 10,000
$ 123,000
**
**
*
**
**
*
$ 328,000
33,000
43,000
**
$ 404,000
*
*
**
**
$ 8,700
**
$ 8,700
$ 33,000
§ 437,000
Estimate
$ 167,000
2,500
***
50,000
28,000
58,000
11,000
44,000
20,000
$ 380,500
190,000
57,000
--
57,000
$ 684,500
$ 40,500
7,500
12,000
2,000
$ 62,000
31,000
$ 93,000
$ 352,000
$ 1,036,500
Difference
.
$ 280,500
$ 84,300
$ 319,000
$ 599,500
This cost element was not broken out as a separate cost
category in the December 1983 FFS.
This cost element was not identified in the December 1983 FFS.
*** This cost element was not broken out as a separate cost
category in the June 1986 cost estimate.
This cost element includes the cost of the carbon vessels and
associated piping, and the initial charge of activated carbon.
**
1)
-------
C. Carbon Adsorption; Hemlock Mutual Water Company.
December 1983 June 1986
CAPITAL COST
Equipment purchase
& installation; carbon
vessels with face
piping & internals
Chlorination system
Installation
Tin-in piping & valves
Foundation
Mobilization & site
preparation
Backwash reservoir & pump
Subtotal
Salvage Value
Contingency
Engineering, legal &
administrative fees
Management services
during construction
Total
ANNUAL OPERATING COST
Activated Carbon
Maintenance
Sampling
Power
Subtotal
Contingency
Total annual operating cost
5-YEAR PRESENT WORTH
OPERATING COST
TOTAL 5-YEAR PRESENT
WORTH COSTS
Estimate Estimate* Differencel
§ 132, 000^ 107,400-
138,500
$ 10,000 ***
$ 85,000 16,400-
17,600
** $ 3,200-
3,500
** 3,300-
5,000
* 5,200-
8,600
** 0-
52,500
$ 227,000 $ 135,800-
225,400
** (5,700)-
0
23,000 67,900-
112,700
30,000 20,400-
33,900
** 20,400-
33,900
$ 280,000 $ 244,500- $ (35,500)-
400,200 . 120,200
* $ 36,000
* 3,500-
5,500
** 12,000-
24,000
** 3,000-
3,500
$ 17,700 $ 54,500-
69,000
** 27,300-
34,500
$ 17,700 $ 81,800- § 64,100-
103,500 85,800
S 67,000 $ 310,000- $ 243,000-
392,000 325,000
$ 347,000 $ 615,700- $ 268,700-
716,200 369,200
* This cost element was not broken out as a separate cost
category in the December 1983 FFS.
** This cost element was not identified in the December 1983 FFS.
*** This cost element was not identified in the June 1986 cost estimate
1) The range of cost figures presented represents the difference
in costs depending on whicl subalternative method of upgrading
Hemlock's existing system : implemented. The subtotals and total
cost figures do not equal ; le sum of the ranges of the di ffornnf;
-------
-26-
D« Combined Cost of Carbon Adsorption for the Three Mutuals.
December 1983 June 1986
CAPITAL COST
Subtotal of primary
capital cost elements
Salvage
Contingency
Engineering, legal, and
administrative fees
Management services
during construction
Total
ANNUAL OPERATING COST
Activated Carbon
Maintenance
Sampling
Power
Subtotal
Contingency
Total annual operating cost
Estimate
$ 1,030,000
**
104,000
136,000
**
$ 1,270,000
*
*
**
**
§ 36,900
**
5 36,900
Estimate1 Difference1
$ 897,800-
984,000
(5,700)-
0
387,000-
432,700
134,700-
148,200
134,700-
148,200
$ 1,616,000- $ 346,000-
1,772,000 502,000
$ 126,000
18,600-
20,600
36,000-
48,000
7,000-
7,500
§ 187,600-
202,100
93,800-
101,000
$ 281,400- $ 244,500-
303,100 266,200
5-YEAR PRESENT NORTH
OPERATING COST
$ 140,000
$ 1,066,000-
1,148,000
$ 926,000-
1,008,000
TOTAL 5-YEAR PRESENT
NORTH COSTS
$ 1,410,000
$ 2,743,000- $ 1,333,000-
2,844,000 1,434,000
This cost element was not broken out as a separate cost
category in the December 1983 FFS.
This cost element was not identified in the December 1983 FFS.
The range of cost figures presented represents the difference
in costs depending on which subalternative method of upgrading
Hemlock's existing system is impelemented. The total cost
figures do not equal the sum of the ranges of the different
cost elements because the different subalternatives have hi
**
1)
CO'
-------
-27-
ALTERNATIVE 3i Mutuals Connect to the Metropolitan Water District
December 1983 Estimate; Capital and operating costs are taken from
the FFS prepared by CH2M Hill (CH2M Hill, 1983). The capital costs
for this alternative were not broken down per mutual since one
reservoir facility would service all three mutuals. Therefore,
the capital costs are shown in the following table as presented
in the FPS.
June 1986 Estimate: Increased water costs to the mutuals under
this alternative have been revised based on the new estimates of
Rurban Homes and Richwood's well flow rates developed by CH2M
Hill during the Pre-Design Study (CH2M Hill, 1984), as well as a
more recent estimate of Hemlock's average flow rate (CH2M Hill,
1986e). In addition, the current cost of uninterruptible, treated
water provided by the Metropolitan Water District (MWD) during
the 1985-1986 fiscal year has been used ($224 per acre-foot).
The cost of MWD water is assumed to be constant over the 5-year
period of the IRM although it is estimated that MWD water rates
will increase at 10% per year for the next five years (CH2M Hill/
1986a). Water costs are calculated as the difference between
present water rates and projected water rates if water is purchased
from MWD.
This alternative, as outlined in the FFS, included a 200,000
gallon storage reservoir which would be used by Richwood, Rurban
Homes, and Hemlock mutuals. The capital cost estimates for the
system components used in the FFS are still used in this estimate
as well. However, the contingency allowance included in the
revised cost estimate has been increased. In the FFS, a small
(approximately 12%) contingency was included, but was only applied
to the capital costs associated with the reservoir, not the
feeder connection and main pipeline costs. In the revised cost
estimate, a 50% contingency allowance has been included and is
applied to all of the capital cost elements. The contingency has
been increased due to several reasons. First, the original
reservoir and pipeline system cost estimate was based on a required
daily water use of 464,000 gallons per day. The current estimate
of the daily water demand of the three mutuals is 763,000 gallons
per day — 64% higher than estimated during the FFS. Therefore,
the size of the reservoir and possibly the pipelines will have to
be larger than contemplated during the FFS. Second, to implement
this alternative an appropriate location for the reservoir would
have to be identified. Depending on the location selected, the
cost of land may vary. In addition, the cost of the main pipeline
is dependent on the reservoir location since its location will
determine the length of the main pipeline. Since a location has
not been specifically identified, inclusion of a large contingency
allowance is warranted. Third, 2 1/2 years have passed since the
original cost estimates, and therefore, construction costs are
probably higher. In fact, as measured by the construction cost
index of Engineering News Record, construction costs have increased
by over 20% over this period. For similar reasons, a 50%
contingency factor has also been applied to the operation and
maintenance costs.
-------
-28-
An estimate for engineering/ legal, and administrative fees
and for management services during construction have also been
included in the revised cost estimates. These costs were not
included in.the FFS, although they would be incurred during
procurement of land for the reservoir and during the design and
construction of the reservoir and associated pipelines.
Combined Costs of Connecting to the Metropolitan Water District
for Rich wood, Rurban Homes
CAPITAL COST
200/000 gallon
storage tank
Land
Pump Station
Feeder connection &
main pipeline
Connection to mutuals
Subtotal
•Contingency
Engineering/ Legal/ &
administrative fees
Management services
during construction
Total Capital Costs
/ and Hemlock
December 1983
Estimate
$ 140/000
130/000
150/000
730/000
36/000
$ 1/186/000
50/000
*
*
$ 1/236/000
Mutual Water Companies.
June 1986
Estimate Difference
$ 140/000
130/000
150/000
730/000
36/000
$ 1/186,000 $
593,000
178/0001
178/0001
$ 2/135,000 $ 899
0
,000
5-YEAR PRESENT WORTH
OPERATION &
MAINTENANCE COSTS
ANNUAL INCREASED WATER
COSTS
5-YEAR PRESENT WORTH
INCREASED WATER COSTS
TOTAL 5-YEAR PRESENT
WORTH COSTS
§ 50,000
$ 94/000
$ 348,000
$ 1/634/000
$ 75/000
25/000
$ 119/000 $ 25/000
$ 451/000 $ 103,000
$ 2,661,000 $ 1,027,000
* This cost element was not included in the cost estimates in
the December 1983 FFS.
1) This cost element has been estimated as 15% of the identifiable
capital costs associated with the construction of the storage
reservoir*
-------
-29-
ALTERNATIVE 4; Mutuals Dissolve and Join With Another Water Company
December 1983 Estimate: Costs for this alternative are taken
from the FFS prepared by CH2M Hill (CH2M Hill, 1983).
June 1986 Estimate; Connection costs for this alternative have
been revised based on more recent estimates of the number of
connections in each of the mutuals' systems — a total of 755
connections for all three mutuals compared with an estimate of
693 used in the FFS. Increased water costs to the mutuals under
this alternative have been revised based on the new estimates of
Rurban Homes and Richwood's well flow rates developed by CH2M
Hill during the Pre-Oesign Study (CH2M Hill, 1984), as well as a
more recent estimate of Hemlock system's average flow rate (CH2M
Hill, 1986e). The revised estimate of the number of connections
in the mutuals' systems also affected the estimate of increased
water costs. Water costs are calculated as the difference between
present water rates and estimated water rates for receiving water
from the San Gabriel Valley Water Company, as stated in the FFS.
Combined Costs for Richwood, Rurban Homes, and Hemlock Mutual
Water Companies to Join With Another Water Company
December 1983 June 1985
Estimate Estimate Difference
ONE-TIME CONNECTION COSTS $ 190,000 " $ 202,000 § 12,000
ANNUAL INCREASED WATER $ 84,000 $ 138,000 $ 54,000
COSTS
5-YEAR PRESENT NORTH $ 316,000 $ 522,000 $ 206,000
INCREASED WATER COSTS
TOTAL 5-YEAR PRESENT $ 506,000 $ 724,000 $ 218,000
WORTH COSTS
-------
-30-
~ -—Customers.
SS^^^SB"^"-"•
sa-jss ,, J^SiSKjKs ~
Combined Cost for Providing Bottled Water to Richwood,
Rurban Homes/ and Hemlock Mutual Water Companies"—
ANNUAL COST OF
PROVIDING
BOTTLED WATER
5rnSVRESBNT OR
COST OF PROVIDING
BOTTLED WATER
Difference
»».394,000
510,459,000 , 865,000
-------
-31-
Increased Water Costs to Mutuals
One consequence of the revised cost estimates for the IRM
alternatives which have been summarized is that the relative
economic impact each alternative will have on the mutuals' members
has been changed. As discussed previously/ OHS had developed a
policy that required that the mutuals assume responsibility for
operation and maintenance of the IRM. The passage of SB 1063 and
DHS's decision to implement its provisions changed this policy
with respect to the carbon adsorption alternative. If this
alternative is implemented/ there will be no significant'economic
impact on the mutuals members. This is also true for the bottled
water alternative since EPA and OHS would pay for bottled water.
However/ the high O&M costs and increased water costs associated
with the other alternatives will cause a large increase in the
mutual members' water bills if those alternatives are implemented.
The average water bill for a member of the mutuals is estimated
at $7-9 per month. The table below summarizes the estimated
estimated average increase in the mutuals' monthly household
water bills for the three alternatives that would cause the
mutuals1 members' water bills to rise.
AVERAGE MONTHLY INCREASE IN MUTUAL MEMBERS' WATER BILLS
Air-Stripping
Connect to MWD
Join With Another
Water Company
Mutual
Rurban Homes
Rich wood
Hemlock
Aver age *
Increase
for Member
$ 11
$ 14
$ 13
Average2
Percent
Increase
140%
180%
160%
Average*
Increase
for Member
$ 13
$ 16
$ 11
Aver age 2
Percent
Increase
170%
200%
140%
Average*
Increase
for Member
$ 15
$ 17
§ 13
Average2
Percent
Increase
190%
220%
170%
1) Based on the following number of households per mutual:
Richwood—217 households/
Rurban Homes—298 households.
Hemlock—240 households
2) Based on an estimated existing average monthly bill of $8 per
household.
-------
-32-
As the table shows/ several of.the IRM alternatives will
lead to large increases in the mutuals1 customers' average monthly
water bills. Of the three alternatives that would increase the
mutuals1 water bills, even the alternative with the lowest annual
costs associated with it (air-stripping) will cause an estimated
increase in the average household monthly water bill of up to 180%
for the Richwood mutual. At the other extreme, the alternative
under which the mutuals join another water company would lead to
an increase of as much as 220% in Richwood's average household
water bill. Although the annual O&M costs of the carbon
adsorption alternative would lead to increases as high as 440% in
the mutuals' average monthly water bills if the mutuals were
paying for O&M, under the provisions of SB 1063 the State will
fund the O&M costs for the carbon adsorption alternative, and
therefore implemenation of this alternative will not affect the
water bills of the mutuals1 customers in any way.
These estimated increased costs to the mutuals for providing
clean water have a large impact on the acceptability of the
different alternatives to the affected community, which in turn
affects the institutional feasibility of the alternatives. In
this situation, to be institutionally feasible an alternative
must be approved by the mutuals prior to implementation. An
alternative that would lead to major increases in monthly water
bills is unlikely to be approved by the mutuals, in which case
the alternative could not be implemented. This was the primary
reason behind EPA's decision to proceed with the design of the
air-stripping alternative even after the results of the Pre-Design
study showed that the cost of carbon adsorption was roughly equal
to the cost of air-stripping (on a 5-year basis). It was not
institutionally feasible to implement the carbon adsorption
alternative when it would have led to five-fold increases in the
mutuals' average household water bills. .
-------
-33-
V. Cleanup Criteria
The Superfund Amendments and Reauthorization Act of 1986
(SARA) $121(d)(2)(A) requires Superfund remedial actions conducted
under $104 and §106 to comply with applicable or relevant and
appropriate requirements, standards/ criteria/ or limitations
(ARARs). ARARs include any standard/ requirement/ criteria/ or
limitation under any Federal environmental law/ as well as any
promulgated standard, requirement, criteria, or limitation under
a State or facility siting law that is more stringent than any
Federal standard/ requirement/ criteria/ or limitation.
Section 121(b) of SARA requires selection/ to the maximum
extent practicable/ of remedial actions that utilize permanent
solutions and alternative treatment technologies that will result
in a permanent and significant decrease in the toxicity/ mobility,
or volume of the hazardous substance/ pollutant, or contaminant.
This section is a discussion of the issues associated with
compliance with Section 121 of SARA.
Objective of the IRM
The objective of the IRM, as described in the May 1984 Record
of Decision, was to ensure that all residents affected by ground
water contamination in San Gabriel Area 1 are provided with a
drinking water supply that is below the EPA Suggested No Adverse
Response Level (SNARL) for a 10~*> cancer risk level for PCE — 4
parts per billion (ppb) [Note that this level was rounded up from
the actual SNARL level of 3.5 ppb.J This level is equal to California
DHS's "Action Level" for PCE which is the level at which DBS
recommends that the water purveyor take some action to lower the
concentration of PCE in drinking water.
The applicable Federal environmental statute is the Safe
Drinking Water Act. Under this law/ EPA establishes drinking
water regulations for contaminants through a two-step process.
First/ EPA promulgates health-based levels termed Maximum Contam-
inant Level Goals (MCLG, previously called Recommended Maximum
Contaminant Levels/ or RMCL) under the Safe Drinking Water Act
Amendments of 1986. MCLGs are set at levels at which no adverse
public health effects would occur and are set at zero for known
or probable carcinogens/ since there is no safe level of exposure
to a carcinogen. MCLGs are unenforceable health goals — public
water supply systems are not required to meet them in water they
deliver to their customers. EPA then establishes Maximum Contam-
inant Levels (MCL) taking into account the availability, cost/
and technical feasibility of water treatment technologies that
can be used to reduce the concentrations of the contaminant in
-------
-34-
public water supplies. MCLs are enforceable standards that must
be met by public water supply systems. In June 1984/ EPA proposed
establishing a RMCL of 0 for PCE since it was considered to be a
carcinogen. EPA has not yet promulgated a final MCLG for PCE,
nor has it proposed a MCL. Therefore, in accordance with the EPA
"Interim Guidance on Compliance with Applicable or Relevant and
Appropriate Requirements" (OSWER No. 9234.0-05), the cleanup
level should be selected based on chemical specific health
advisory levels such that the total risk of all contaminants
falls within the acceptable risk range of 10~4 to 10~7.
Therefore, the cleanup objective of the IRM should be set
based on the PCE health advisory, while also taking into
consideration other Federal and State criteria, advisories, and
guidance. Health advisories issued by the EPA Office of Drinking
Water. The SNARL level for PCE (4 ppb) that was used in the 1984
Record of Decision was considered the health advisory for PCE at
that time by the Office of Drinking Water and is also the California
DHS "Action Level", which is an unenforceable health goal and is
the level at which DHS recommends taking corrective action to
lower the contaminant level in drinking water. The carcinogenic
risk estimate used to establish the SNARL was developed by the
National Academy of Sciences (NAS) in its Drinking Water and
Health study. In September 1985, the Office of Drinking Water
issued a new draft health advisory for PCE that included revised
cancer risk estimates for exposure to PCE in drinking water that
were developed by EPA's Carcinogen Assessment Group (CAG). The
new health advisory for PCE estimates that the concentration
equivalent to a 10~6 cancer risk level is 0.7 ppb. This compares
with a concentration of 3.5 ppb that the NAS study determined was
equivalent to a 10~6 cancer risk level (which was rounded to 4 ppb
in setting the public health objective of the IRM in the 1984
ROD). Both the NAS and CAG risk assessments were based on the
same toxicological data, however, different assumptions were
utilized in developing the cancer risk estimates. The California
DHS action level is still based on the NAS risk assessment for
PCE.
Although the proposed MCLG for PCE is 0 and the new draft
health advisory of the EPA Office of Drinking Water is 0.7 ppb
(as the 10~6 cancer risk level), it is recommended that the PCE
concentration limit be set at 1 ppb for the San Gabriel Area 1
interim remedial action. Since no MCL exists yet for PCE, the
CAG health advisory, along with the DHS action level, should be
considered in the development of applicable or relevant and
appropriate requirement for PCE. The standard detection limit
obtained by a good laboratory for PCE, analyzed in conformance
with EPA Method 601 for purgable halocarbons, is 1 ppb, and
confidence levels for concentrations of less than 1 ppb are
questionable. The recommended alternative, installation of a
carbon adsorption treatment system,, will have no problem reducing
PCE levels to below the detection limit at essentially no additional
cost over the cost of just meeting the DHS action level (and goal
-------
-35-
of the IRM in the 1984 Record of Decision). Therefore, a PCE
concentration limit of 1 ppb is recommended since it appears that
this level is simultaneously most protective of public health and
technologically feasible. Several other Federal/ State, and
local environmental requirements are applicable or relevant and
appropriate and have been considered in developing the IRM
alternatives.
Meeting Applicable or Relevant and Appropriate Requirements
In developing the different IRM alternatives, it has been
assumed that each alternative would be implemented so that it
would comply^with all Federal, State, and local environmental
requirments. The specific requirements as they apply to each of
the alternatives are summarized here:
Air-Stripping — The conceptual design and cost estimates
of the air-stripping alternatives (with and without the in-ground
storage reservoir), as described in the 1986 pre-design studies,
are based on a cleanup goal of 4 ppb for PCE. In order to treat
groundwater (with contaminant levels at the maximum design
concentrations) to the detection limit of PCE (1 ppb) and approach
the 10""** cancer risk level as stated in the EPA drinking water
health advisory, the air-to-water ratio would need to be increased
by up to 20%. In addition, the packing depth of the tower's would
have to be increased by 15-20 feet. As a result, capital costs
would be significantly higher, and the cost of power to operate
the system would also be significantly increased. [Note: These
additional costs to treat to the detection limit for PCE are not
included in the cost summaries on pp. 17-20 and in Table 1. The
cost in those tables assume a target concentration of 4 ppb PCE.J
The air-stripping alternatives would be affected by several
environmental requirements. Since an air-stripping system would
emit PCE to the atmosphere from the top of the stripping tower,
it would be subject to the South Coast Air Quality Management
Note: In accordance with the provisions of §121(e)(l) of the
Superfund Amendments and Reauthorization Act of 1986 (SARA),
the initial remedial measures implemented will meet the
substantive requirements of the Federal, State, and local
environmental laws and regulations cited in this section.
EPA is not required, however, to obtain the Federal,
State, or local permits required under these laws and
regulations. Nevertheless, the mutuals may apply for the
normally required permits in the course of EPA implementation
of the selected initial remedial measures. EPA reserves
the authority under-SARA to implement the project without
obtaining permits (while meeting all the substantive
requirements that apply) if it is necessary to maintain
the project schedule.
-------
-36-
District's (SCAQMD) Rule No. 402. In anticipation of complying
with SCAQMD's requirements, Richwood and Rurban Homes submitted
air emissions permit applications to SCAQMD in September 1985.
SCAQMD's permit review process for air-stripping towers consists
of a modeling analysis to determine the maximum ambient concentra-
tion of pollutants that would occur due to the system's emissions,
followed by a calculation of the maximum individual cancer risk
that would be associated with that ambient concentration. As
part of SCAQMD's review of Richwood and Rurban Homes' permit
applications/ SCAQMD staff performed a screening air quality
model analysis of the maximum estimated emissions from the air-
stripping systems. Estimated maximum long-term (annual-average)
ambient concentrations of PCE (and other trace contaminants/
trichlorethylene and carbon tetrachloride) were developed. Based
on EPA estimates of cancer risk levels associated with exposure
to ambient concentrations of these contaminants/ SCAQMD calculated
the maximum individual risk associated with exposure to the
emissions from the air-stripping systems. For Richwood/ the
maximum individual cancer risk was 6xlO~7/ while for Rurban Homes
the maximum individual cancer risk was 7xlO~8. Both of these risk
estimates are below the 10~6 cancer risk level being used as the
target risk level for exposure to PCE in the mutuals' drinking wate
The air-stripping systems would also be subject to requirements
of the Clean Water Act as established under a National Pollutant
Discharge Elimination System (NPDES) permit. The Clean Water Act
is administered by the Los Angeles Regional Water Quality Control
Board (RWQCB). The air-stripping system would fall under NPDES
requirements due to the planned discharge of wastewater associated
with the periodic (approximately monthly) disinfection of the
air-stripping towers to a nearby storm sewer system. The discharge
would also comply with requirements of the Los Angeles County
Department of Public Works which regulates discharges to the
storm sewer system.
The air-stripping system would also be subject to requirements
of the Sanitary Engineering Branch (SEB) of California DHS, as
well as the Planning Department of the City of El Monte. DHS
requirements::involve a modification to the mutuals' present water
supply system permit/ and primarily consist of DHS approval of
the modification to the mutuals' water supply system. The City
of El Monte has requirements for conditional use permits in
situations where non-residential facilities are constructed in a
zoned residential area/ such as where the mutuals1 well sites are
now currently located.
Carbon Adsorption ~ The carbon adsorption alternative would
treat PCE in groundwater to detection level (1 ppb) and thereby
achieve the most protective technologically feasible cleanup
level. The existing carbon adsorption system conceptual designs
could meet this objective without any significant additional cost.
-------
-37-
This alternative is subject to the same requirements as
is the air-stripping alternative with the exception of the SCAQMD
requirements (since the carbon adsorption alternative would
involve no emissions to the air). Therefore/ DHS and City of £1
Monte requirements would apply/ as well as NPDES requirements and
Los Angeles County Department of Public Works requirements. In
this case/ however/ the wastewater discharge subject to NPDES
requirements is the periodic backwash of the carbon beds. Clean
water is forced through the beds to eliminate channeling and
reduce packing of the beds to improve carbon adsorption system
performance. The backwash water would then be discharged to the
storm sewer. This discharge would be subject to NPOES requirements/
as well as Los Angeles County Department of Public Works requirements.
In keeping with SARA preference for using treatment
technologies that significantly and permanently reduces the volume/
toxicity or mobility of contaminants to the maximum extent
practicable/ the spent carbon would be regenerated for reuse
through high temperature incineration. This would essentially
permanently destroy the contaminants. If the spent carbon is
determined to be a hazardous substance/ it will require disposal
or treatment in accordance with RCRA regulations.
Connect to MWD and Join With Another Water Company — The
primary requirement affecting these two alternatives would be the
DHS public water supply permit requirements due to the modification
of the mutuals1 present water supply system. The Connect to MWD
alternative/ however/ would also be subject to City of El Monte
Planning Department requirements concerning the construction of
the storage reservoir. Currently/ the State Action Level of
4 ppb of PCE is the level to which the public water suppliers
in San Gabriel areas 1-4 are operating to achieve. The <1 ppb
concentration level/ which would be achieved under the carbon
adsorption alternative/ would not necessarily be achieved by
connecting to another water company.
Bottled Water — This alternative would not be subject to
any specific requirements. With regards to EPA's proposed MCL
standards for other volatile organic compounds (and likely to
apply to a PCE MCL as well)/ bottled water is not considered an
acceptable permanent means of meeting MCL requirements (50 Federal
Register/ pg. 46916)/ although it is considered an acceptable
interim measure until permanent means of meeting the MCL are
implemented. Therefore/ in this situation where the IRM is
considered an interim remedy to provide the mutuals with clean
water in the interim period until a comprehensive remedial action
is implemented/ bottled water can be considered an acceptable IRM
alternative in accordance with EPA's proposed MCL standards for
volatile organic compounds.
-------
-38-
VI. Recent Community Relations Activities
Based on the new information regarding the costs of air-
stripping and carbon adsorption systems EPA prepared a draft
report, "Revised Cost-Effectiveness Analysis of Alternatives for
the San Gabriel Area 1 Initial Remedial Measures." This report
proposed that EPA revise its previous decision selecting air-stripping
as the cost-effective alternative for the San Gabriel Area 1
Initial Remedial Measures and now select carbon adsorption as the
cost-effective IRM alternative. In October 1986, EPA released
this draft report for public review and comment. A fact sheet
that summarized the report and EPA's proposed action was prepared
and distributed to everyone on the San Gabriel sites mailing list.
In addition, EPA provided the three mutuals with copies of the
fact sheet for distribution to their shareholders. Copies of the
report were distributed to California OHS and directly to the
three mutual water companies affected. The report was made
available at three information repositories that had been previously
established for this project: 1) El Monte Public Library in El
Monte; 2) Norwood Public Library in El Monte; and 3) EPA Region 9
Office in San Francisco. The fact sheet that was distributed
announced the availability of the report, the location of the
information repositories, and the scheduled public comment period
which ran from October 10, 1986 to October 31, 1986.
A public meeting was not scheduled during the public comment
period. It was felt that the interest level in this proposed
action did not warrant a public meeting. Less than ten members
of the public attended the December 19, 1983 public meeting that
was held to accept comments on the December 1983 Focused Feasibility
Study. No individuals in attendance at that meeting chose to
make an oral statement or to submit written comments at that
time. Only two public comments were submitted during the December
1983 public comment period. In addition to the lack of interest
in EPA's proposed project in the past, it was also known from
meetings with the mutuals' board members that the mutuals supported
EPA's proposed change of selection of remedy for the IRM.
Therefore, it was decided to forego the scheduling of a public
meeting unless requests for such a meeting were obtained for the
public—no such requests were received. EPA did offer to schedule
a meeting for the mutual members upon request.
EPA received two written comments during the public comment
period. One commentor supported the selection of the alternative
under which the mutuals would dissolve and join another water
company. The second commentor while stating a preference for the
carbon adsorption alternative, believed that air-stripping
treatment is the most cost-effective alternative. EPA's response
to these comments is summarized in the attached responsiveness
summary.
-------
-39-
In addition to the public comment period, EPA specifically
asked the mutuals to respond to EPA with their preferences regarding
the alternative initial remedial measures. Both Richwood and
Rurban Homers Mutual Water Companies provided letters to EPA
stating that they were in agreement with the EPA proposal to
revise the selection of alternative for the San Gabriel Area 1
initial remedial measures from air-stripping to carbon adsorption
treatment systems. The president of Hemlock Mutual Water Company
advised EPA that the Hemlock board of directors had decided not
to request that the proposed upgrade to their carbon adsorption
system be implemented/ and therefore., requested that they not be
included in the initial remedial measures project at this time.
-------
-40-
VII. Current Status of the Mutuals1 Water Supply
Richwood Mutual Water Company
In June 1985, the PCE level in Richwood's North Hell
approached 100 ppb (and one sample collected by the mutual showed
a concentration of 110 ppb PCE). Because these contaminant levels
are approximately 25 times the state action levels, DHS made a
determination of imminent or substantial endangerment, pursuant
to section 2535S.3 of the health and safety code/ and funded the
installation of a temporary emergency connection of Richwood to
the San Gabriel Valley Hater Company (SGVWC). Since that time,
Richwood's wells have been shut down and its members have been
obtaining their water from SGVWC. SGVWC entered into a temporary
service agreement with Richwood that provided for SGVWC to
furnish water to Richwood on a temporary basis until the water
treatment system being constructed by EPA was installed and in
operation. SGVWC reserved the right to limit, curtail, or
terminate the agreement at its discretion if in its judgement, it
determines that conditions within its water system warrant such
limitation, curtailment, or termination. Because of the temporary
nature of the agreement and its implementation on the assumption
that EPA would continue to design and install a treatment system,
it is recommended to continue with the implementation of the
initial remedial measures for Richwood Mutual Water Company at
this time.
Rurban Homes Mutual Water Company
The last time Rurban Homes' wells were sampled (1/31/85)
before the October 1986 public comment period on EPA's revised
cost-effectiveness analysis, Well No. 1 showed a PCE concentration
of 4.4 ppb, just above the OHS action level. This well has had a
maximum PCE concentration of 54 ppb in the past. Since the
public comment period, the wells have been sampled monthly for
the first five months of 1987 as part of the Assembly Bill 1803
sampling program currently being conducted by the Main San Gabriel
Basin Watermaster. All of the historical sampling data from
Rurban Homes' wells that are in the current San Gabriel remedial
investigation/feasibility study (RI/FS) database are listed in
Tables 3 and 4. PCE has not been detected at all in Well No. 2
in 1987. The laboratory has reported values of PCE of 0.68 -
1.14 ppb in Well No. 1 in five samples collected in 1987. This
is essentially the limit of quantification for PCE analysis.
At this stage in the San Gabriel RI/FS, the knowledge of the
sources, extent, and character of the groundwater contamination
is not detailed enough to determine the reason for this drop in
contamination levels. The influence o : other wells pumping in
the vicinity or changing water levels ay have affected contaminant
migration, or a slug of contamination
-------
-41-
It is recommended that initial remedial measures for the
Rurban Homes Mutual Water Company be not implemented at this time
since the contaminant levels have remained steady at the levels
recommended as the public health goal for the IRM through the
first half of 1987. It is also recommended, however, that the
design and preparation of bid documents for the IRM for Rurban
Homes be completed at this time. The reason for this is that
there have been several wells in the San Gabriel Valley that have
had contaminant levels that have fluctuated from below DBS action
levels to levels much higher than OHS action levels. Given our
lack of knowledge of the character of the groundwater contamination
in the vicinity of the Rurban Homes wells, it would be prudent to
have the design completed so that if regular monitoring shows the
contaminant levels increasing again or if other investigations
determine that upgradient contamination threatens the wells,
immediate action can be taken to protect public health. This
approach has been discussed with the President of the Rurban
Homes Board of Directors, who had no objections to this approach
and informed the other members of the Board of Directors.
Hemlock Mutual Water Company
Hemlock's existing carbon adsorption system was designed in
1983 and became operational in March 1986. It is currently
operating and is treating water pumped from Hemlock's two wells.
Sampling data for 1987 show contaminant levels in Hemlock's two
wells ranging from less than 10 ppb PCE (including one analysis
that came back nondetectable for PCE) to as high as 150 ppb. The
existing carbon adsorption system has an empty bed contact time
(EBCT) of 5 minutes at peak flow, with.peak flow limited to 360
gallons per minute. The normal design criteria EBCT for carbon
adsorption systems treating water contaminated with volatile
organic compounds is 10-15 minutes.
It was proposed to upgrade Hemlock's existing system to the
design standards of the Richwood and Rurban Homes carbon adsorption
system conceptual designs. Hemlock informed EPA that it did not
wish to have the upgrade of its existing system implemented at
this time. Nevertheless it is recommended to still select a
cost-effective IRM alternative for Hemlock, but to not implement
it at this time. It would be implemented in the future only is
it is determined that there are problems with their present system
that make it necessary to implement' the IRM alternative in order
to protect public health. This would allow EPA to take more
expeditious action in the event that additional action to protect
public health is necessary.
-------
-42-
VIII. Comparison of Alternatives
As previously discussed/ much work has been done to further
evaluate the air-stripping and carbon adsorption alternatives
since the Record of Decision for the San Gabriel Area 1 IRM
was approved in May 1984. This additional evaluation, along with
the development of more refined estimates of the amount of water
used by the mutuals, has led to cost estimates that are very
different from those identified in the Record of Decision. In
addition/ there has been further evaluation of the non-cost
factors that should be taken into account in the selection of
an IRM alternative for implementation. In this section/ the
relative advantages and disadvantages of the IRM alternatives
that were considered are discussed. These advantages and
disadvantages are also summarized in Table 2.
Treatment of Well Discharge With Air-Stripping System
Two different configurations of the air-stripping system
alternative were considered. The air-stripping configuration
that does not include an in-ground storage reservoir was the
second lowest-cost alternative. This configuration of the air-
stripping system alternative is the IRM action originally selects
in the May 1984 Record of Decision. Although this air-stripping
system configuration has a lower overall cost than the configuration
that includes the reservoir/ it was determined during the Pre-Design
Study prepared by CH2M Hill (CH2M Hill, 1984) that this configuration
(without a storage reservoir) could have potentially serious problems
regarding the reliability of the system. The constant cycling on
and off of the system could cause excessive equipment wear.
Also/ this configuration would require a microprocessor control
system to control the cycling of the system. The mutuals presently
have no experience in operating a complex control system.
In addition/ this configuration may cause several negative
impacts on the mutuals and the surrounding community. These
impacts include: 1) potential noise problems associated with
near 24-hour operation of the air-stripping towers; 2) possible
frequent power surges and disruptions caused by the constant
cycling on and off of electrical equipment associated with the
treatment system; and 3) a major change in the way the mutuals
operate their water systems since they presently have no experience
in operating a complex waterworks system.
By including a storage reservoir in the air-stripping system/
the potential for problems concerning system reliability is
reduced/ while the other adverse impacts on the mutuals and
surrounding community are also mitigated. The inclusion of a
storage reservoir however/ increases the 5-year cost of air-stripping
to the point where it is higher in cost than every alternative
except for providing bottle water to the mutuals. Also/ construction
of a 60/000 gallon storage reservoir at the mutuals' well sites would
be difficult due to the limited site area available/ particularly
-------
-43-
at Richwood'a well site. Excavation of the reservoir would be a
major operation that would have a large effect on the neighboring
landowners since the construction would have to be staged on the
adjacent lots.
There are two advantages that are common to both air-
stripping configurations. First/ air-stripping has the lowest
annual cost (O&M plus increased water costs) of all the alternatives.
Also/ the annual cost is not as sensitive to the level of
system. Second/ the air-stripping treatment system has the
advantage of actually beginning to clean the contaminated ground
water-that is present. Thus/ it is consistent with a long-term
goal of restoring the aquifer to an uncontaminated state and
ensures that at least in the area of influence of the mutuals
wells/ the contamination will not continue to migrate/ thereby
potentially affecting other wells. Of course/ there is. also a
small possibility that continuing to pump the ground water could
draw pockets of highly contaminated ground water toward existing
wells/ however/ the effect of the pumping cannot be predicted
definitively at this time since the extent of contamination has
not been entirely defined.
Both configurations of air-stripping also share several
disadvantages/ as well. One disadvantage is the size of the
systems and its associated visual impact. The stripping towers
would be approximately 30-35 feet tall, and therefore/ would
stand out in a residential neighborhood of predominantly single-
story buildings. If contaminant concentrations exceed the
maximum design concentrations/ the air-stripping system may not
meet the public health objective of the IRM without modification
of the system. Air-stripping would also not be effective if
other/ nonvolatile organic compounds (VOC) are present in the
ground water. Based on the results of EPA/ state/ and local
water agency sampling/ however/ it appears that only VOC
contamination is prevalent in San Gabriel Area 1. Another
disadvantage is that air-stripping systems would emit measureable
amounts of PCE into, the atmosphere. This is a potential
concern since the location of the wells is in the highly polluted
South Coast Air Quality Basin. As previously discussed/ SCAQMD
modeling of the emissions concluded that the maximum individual
cancer risk levels associated with the air emissions from the
air-stripping towers would be less than the 10~6 cancer risk
levels on which the public health objective for drinking water in
the IRM is based. However/ there is a non-zero risk (6xlO~7)
associated with the air emissions which may be of concern to the
community since the treatment systems would be constructed in the
middle of residential neighborhoods. Finally/ a major disadvantage
of the air-stripping alternative is that it would have a negative
impact on the affected community due to the estimated increase in
the average household water bill of 140-180% for the mutuals1
members
-------
-44-
Another disadvantage with the air-stripping systems are that
the existing conceptual designs (and the associated cost estimates)
as described in the 1986 pre-design studies/ are based on a
cleanup goal of 4 ppb for PCE. In order to treat groundvater to
the detection limit of 1 ppb (which approaches the 10*"6 cancer
risk level of 0.7 as stated in the EPA draft health advisory for
PCE)/ the air-to-water ratio would need to be increased by up to
20%. In addition/ the packing depth of the towers would probably
have to be increased by 15-20 feet. As a result/ the capital
costs would be significantly higher than currently estimated and
the power costs would increase during operation.
Finally/ a last disadvantage is that the air-stripping
alternative just transfers the contaminants from water to air/
and thus/ does not meet the SARA preference for using treatment
technologies that would significantly and permanently reduce the
volume/ mobility/ and toxicity of contaminants to the maximum
extent practicable.
Join With Another Water Company
Of the other potential alternatives/ Alternative 4—Join
With Another Water Company—has the lowest overall cost. This
alternative/ however/ cannot be implemented unless the mutuals
vote to dissolve as independent water companies and transfer
their water rights to the San Gabriel Valley Water Company. When
this alternative was presented to the mutuals as a potentially
cost-effective IRM after completion of the FFS, the mutuals'
shareholders voted to remain independent. Therefore/ though
this alternative is a low-cost and effective alternative/ it
cannot be implemented.
Also/ as was discussed in Section IV./ although the other
alternatives would under most conditions attain the proposed RMCL
of 0 for PCE in the water being delivered to the mutuals/ this
alternative potentially would not. This is due to the fact that
the San Gabriel Valley Water Company currently has several
contaminated" wells and must treat some water or blend clean and
contaminated water to ensure that all water delivered to customers
meets the public health objective of the IRM of 4 ppb (equal to
the DBS "Action Level"). Therefore/ while this alternative would
definitely meet the public health objective of the IRM/ it may
not attain the health-based goal for drinking water quality as
identified in the proposed RMCL for PCE. In addition/ unlike the
treatment alternatives/ air-stripping and carbon adsorption/ under
this alternative no steps would be taken to remove the contaminants
from the ground water/ thereby allowing the contamination to
continue to migrate while the mutuals1 wells are shut down.
In addition/ this alternative would have the adverse impact
on the affected community of raising the average water bill of
the mutuals' members by an estimated 170-220%. It would also be
-------
-45-
irrevocable, in that once the mutuals are taken over by another
water company/ the situation is premanent. Thus, through a
contamination problem that was no fault of their own/ the mutuals1
members would face higher water bills in prepetuity even if
contamination levels in their wells were to be reduced drastically
by future remedial actions and/or.contaminant migration.
Bottled Water
Providing bottled water to the mutuals is the highest cost
alternative. This alternative has a 5-year cost of more than three
times the next highest cost alternative. It would also be less
effective than the other alternatives since it would be provided
only for cooking and drinking/ while the mutuals' members could
still be exposed to PCE while bathing. Since it costs more and
would be less effective than the other alternatives/ it is not a
cost-effective alternative.
Connection to the Metropolitan Water District
The remaining two alternatives (connection to MWD and carbon
adsorption) both have approximately the same 5-year cost/
approximately 15-20% below the 5-year cost of the air-stripping
system configuration that included the storage reservoir.
Although connecting to MWD would effectively meet the public
health objective of the IRM, there are several disadvantages to
implementing this alternative. First/ the high cost of water
from MWD would have a large impact on the mutuals' members. This
alternative would lead to an increase in the average household's
water bill of from 1401-200%. The water bills would probably
increase further because/ although constant annual costs were
assumed in the cost estimates for this alternative based on MWD's
current water prices/ the cost of MWD water is expected to rise
10% per year over the next 5 years.
Second/ the actual capital cost of implementing this
alternative may be higher than estimated. The uncertainty in
capital cost for this alternative is greater than the other
alternatives because the estimate was made without a particular
location (which would be away from the mutuals' well sites) for
the storage reservoir identified. Factors such as variance in
land costs/ distance to the MWD aqueduct and the mutuals'
distribution systems/ ease of obtaining easements for pipeline
construction/ and site characteristics could all affect the final
implementation costs.
Third/ another disadvantage of this alternative is that
it is likely that more time will be required to implement this
remedy. Air-stripping or carbon adsorption systems can probably
be designed and constructed in approximately 8 months. To connect
the mutuals to MWD would probably take over a year since the
reservoir site would have to be located/ negotiations over the
price of the property conducted/ title closure would have to take
-------
-46-
place, easements for pipeline construction would have to be
obtained/ and then finally the design and construction of the
waterworks facilities could occur.
Fourth, as with the alternative of joining with another
water company, under this alternative no steps would be taken to
remove the contaminants from the ground water/ thereby allowing
the contamination to continue to migrate while the mutuals' wells
are shut down.
Treatment of Well Discharge With Carbon Adsorption
The remaining alternative/ carbon adsorption/ has a 5-year
cost approximately equal to the cost of connecting the mutuals to
MWD. It is approximately 15% more costly than the air-stripping
configuration that does not include the storage reservoir/ but
15% less costly than air-stripping when the storage reservoir is
included. A carbon adsorption treatment system has several
non-cost advantages. Its installation small well sites would be
easier than installing the air-stripping system with the in-ground
reservoir since the excavation necessary would be much less.
Although Richwood's carbon adsorption system (and one of the
Hemlock subalternative systems) would require excavation to
install the backwash system/ the excavation would be much less
involved since the size of backwash storage is only 14/000 gallons
as compared to the 60,-000 gallon storage reservoir planned for
the air-stripping system (with storage reservoir). It would/
however/ be more difficult to install than the air-stripping
alternative that does not include the reservoir storage. Carbon
adsorption also offers potential public health advantages since
it can remove a wide spectrum of organic pollutants in addition
to PCE. In addition/ if contaminant levels rise above the design
concentration levels/ a carbon adsorption system should still be
able to adequately remove the contaminants (although operating
costs may increase accordingly). This is potentially a major
advantage given the fact that the plume of ground water contamination
in San Gabriel Area 1 is not completely characterized and pockets
of high contamination or multiple contaminants may not have been
identified yet. In addition/ the current carbon adsorption design
can treat tile water down to the detection limit of PCE (1 ppb)/
thereby essentially meeting the 10"6 cancer risk level for PCE as
stated in the EPA draft health advisory without any modification
of the system and at essentially no or minimal additional cost
(the carbon may have to be recharged slightly more often to
maintain the 1 ppb level in effluent water).
The carbon adsorption alternative has several Important
advantages regarding the expected impacts on the affected community.
A carbon adsorption system will have less potential for creating
a noise problem in the community than the air-stripping alternative
(although new booster pumps will increase the noise somewhat).
As a smaller system/ there will be less visual impact in a community
of single-story residential homes if carbon adsorption is implemented
-------
-47-
instead of air-stripping. Finally/ because of the intention of
DHS to implement the provisions of SB 1063, there will be no
adverse financial impact on the mutuals' members from implementation
of the carbon adsorption alternative since DHS will provide
funding for system O&M.
The primary disadvantage of carbon adsorption is that its
annual costs are significantly higher than any of the other
alternatives (except bottled water). This is a disadvantage if
the IRM alternative is operated beyond the estimated five years
before a comprehensive remedial action is implemented for San
Gabriel Area 1. The following table presents the overall costs
if 20 years is used as the project life instead of 5 years (20
years can be considered the design life of the treatment system
equipment).
TWENTY YEAR PRESENT WORTH COSTS ASSOCIATED
WITH SELECTED IRM ALTERNATIVES
Alternatives
Air-Stripping
(with storage
reservoir)
Air-Stripping
(without stor-
age reservoir)
Carbon
Adsorption
Connect with
MWO
Capital Costs
$ 2,833,000
$ 1,949,000
$ 1,616,000-!
1,772,000
$ 2,135,000
20-Year Present
Worth O&M
or Increased
Water Costs
$ 978,000
978,000
$ 2,396,000-1
2,581,000
$ 1,181,000
20-Year
Present Worth Costs
$ 3,811,000
$ 2,927,000
$ 4,073,000-1
4,197,000
$ 3,316,000
1) The range of cost figures represents the difference in total
costs for all three mutuals depending on which subalternative
method of upgrading Hemlock's existing carbon adsorption system
is implemented. The total cost figure does not equal the sum of
the ranges given for capital and O&M costs because the Hemlock
subalternatives with higher capital costs have lower O&M costs.
-------
-48-
AS can bs seen from the table/ on a twenty-year basis/ the
cost of carbon adsorption is 9% higher than the cost of the
air-stripping configuration that includes a storage reservoir/
25% higher than the cost of connecting to the MWD (although this
is based on the highly unlikely assumption of a constant cost for
MWD water over 20 years)/ and 40% higher than the air-stripping
configuration that does not include a storage reservoir.
Another disadvantage of the carbon adsorption alternative is
that there will be a small amount of air emissions associated
with the regeneration of the carbon at the carbon recycler's
regeneration facility. The amount of emissions/ however/ would
be substantially less than the emissions associated with the air-
stripping alternative/ since they will be controlled at the
recylcer's facility. Also/ by using high temperature incineration
to regerate the carbon for reuse/ this alternative meets the SARA
preference for using to the maximum extent practicable treatment
technologies that significantly and permanently reduces the
volume/ mobility/ and toxicity of contaminants/ as the regeneration
process essentially permanently destroys the contaminants trapped
in the spent carbon.
-------
-49-
IX. Recommended Alternative
SARA, in addition to Section 300.68(i) of the National
Contingency Plan (40 CFR Part 300), defines the appropriate extent
of remedial-action. Remedies must be protective of human health
and the environment. Remedies that attain or exceed applicable
or relevant and appropriate requirements are protective. The
selected remedy must also be cost-effective; that is, it must
confer a level of protection that cannot be achieved by less
costly alternatives. SARA expresses a preference for treatment
that permanently and significantly reduces volume, toxicity, or
mobility of contaminants to the maximum extent practicable.
This revised cost-effectiveness analysis has summarized the
additional .evaluation of cost estimates and other non-cost factors
concerning potential IRM alternatives that has occurred since the
IRM Record of Decision was signed in May 1984. On the basis of
this evaluation, EPA has determined that the May 1984 decision
selecting air-stripping as the cost-effective alternative be
revised, and that carbon adsorption be selected as the cost-
effective IRM alternative, including the upgrade to Hemlock's
current carbon adsorption system.
There are three alternatives with a total 5-year cost below
that of carbon adsorption. The lowest cost alternative (join
with another water company), however, has been determined to be
institutionally infeasible because the mutuals would not approve
it. The next lowest cost alternative, an air-stripping system
that does not include a storage reservoir has potential reliability
problems, and could cause several adverse impacts on the affected
community. The third lowest cost alternative, connect to MWD, is
virtually equal in cost to carbon adsorption when taking into
account the accuracy of the cost estimates (the estimated cost of
carbon adsorption is within 3-8% of the estimated cost of connecting
to MWD). Of these lower cost alternatives and the remaining
alternatives, however, carbon adsorption has a better balance of
advantages to disadvantages as far as non-cost factors are concerned
The primary advantages of the carbon adsorption alternative are:
0 More protective of public health since it can treat to the
detection limit of PCE (without any additional cost, unlike
the air-stripping design which would have to be modified to
achieve that level of treatment) and will entail minimal
air emissions of PCE (at a thermal regeneration facility).
Also, carbon adsorption can effectively treat contaminant
levels much higher than previously found in the mutuals
wells and can remove other non-VOC organics if they
contaminate the wells. These latter advantages are
potentially significant due to our lack of definitive
knowledge regarding the sources, extent, and character of
the San Gabriel Valley groundwater contamination at this
early stage of the remedial investigation/feasibility study.
-------
-50-
0 Meets SARA preference for use of treatment technologies by
essentially destroying contaminants trapped on spent carbon
during the thermal regeneration process.
0 With SB 1063 being implemented by DBS, the financial impact
on the mutuals' members is mitigated through the State's
funding of operation and maintenance. With the other
alternatives, the water bill for the mutuals1 members would
increase by 140 - 220%. In addition, potential problems
caused by the mutuals' lack of experience in operating a
complex water treatment system would be avoided with OHS
operation of the systems.
* Smaller potential impacts on the community (such as less
visual impact and less potential for noise impacts) than
the air-stripping alternative without the storage reservoir.
0 By continuing to use the mutuals1 wells rather than shutting
them down, may contribute to reduced migration of contamination
(though to what exent, if any, is unknown at this time due
to our lack of knowledge concerning the sources and extent
of contamination) than if non-treatment alternatives (e.g.,
connection to the Metropolitan Water District) is implemented
The only significant disadvantage for carbon adsorption is
that its annual costs are much higher than other alternatives so
that over a long period of time it would be an even more costly
alternative. Although it is possible that the IRM may become
part of the final remedial action alternative, the objective of
the IRM is to provide a solution for the mutuals' contamination
problem in the interim period before the San Gabriel Areas 1-4
Remedial Investigation/ Feasibility Study is completed and a more
comprehensive remedial action is implemented, which is expected
to take approximately 5 years. On a 5-year basis, the cost of
carbon adsorption is favorable compared to the other alternatives
when taking into account its non-cost advantages.
A cost summary of the recommended alternative is shown in
the table on the following page. While the selection of the
carbon adsorption alternative for all three mutuals is recommended,
it is also recommended that only the Richwood system be installed
at this time. It is recommended that the design and development
of bid documents for the Rurban Homes system be completed at this
time, but that actual installation of the system only occur if
continued monitoring of the contaminant levels in Rurban Homes'
wells or other investigations show an increase or potential
increase in the contaminant levels in their wells for which it is
determined the treatment system is necessary to protect public
health. In addition, since Hemlock requested that the upgrade to
their system not be implemented at this time, it is recommended
that it be implemented in the future only if it is determined
that there are problems with their present system that make it
necessary to install the upgrade to protect public health:
-------
-51-
COST SUMMARY OF THE SELECTED ALTERNATIVE
Total
5-Year 5-Year
Capital Present Present
Mutual Cost Worth Worth
Richwood $ 684,500 $ 352,000 $ 1/036,500
*Rurban Homes $ 687,100 $ 404,000 $ 1,091,100
**Hemlock $ 244,500- $ 310,000- $ 615,700-***
(upgrade to 400,200 392,000 716,200
present system)
Due to the recent drop in contaminant levels in Rurban Homes'
wells, the treatment system will not be implemented at this
time if continued monitoring of the wells shows the contaminant
levels remaining near detection limit (1-4 ppb). However,
complete design plans and bid documents will be prepared and EPA
will implement the alternative if future monitoring and
investigations show a rise or potential rise in the contaminant
^ levels found in the wells.
In response to Hemlock's preference, the upgrade to their
present system will not be implemented at this time. However,
if their system has problems in the future, EPA will implement
the upgrade to their system.
The range of cost figures represents the difference in costs
depending on which subalternative method of upgrading Hemlock's
existing system is implemented. The subtotals and total cost
figures do not equal the sum of the ranges of the different
cost elements because the different subalternatives with higher
capital costs have lower operating costs.
-------
-52-
Continued Operations and Operation and Maintenance
DBS will be responsible for continued operations and operation '
and maintenance (O&M) of the carbon adsorption systems once they
are installed. EPA will provide 90% of the funding for continued
operations of the treatment system until the final remedial
action alternative for San Gabriel Area 1 is implemented (currently
estimated as approximately 5 years). Funding will be provided to
DBS through a Cooperative Agreement. The annual continued
operations and O&M costs for the Richwood carbon adsorption
system (the only system being implemented at this time)/ as well
as the estimated O&M costs for the Rurban Homes system and Hemlock's
system if it was upgraded/ are shown below:
Annual Continued
Operations and Operation
Mutual & Maintenance Costs
Richwood - $ 93/000
Rurban Homes $ 106/600
Hemlock $ 81/800 - $ 103/500
Schedule
Complete Design November 30, 1987
Complete Construction June 30/ 1988
Award of Cooperative Agreement for
Continued Operations Costs June 30/ 1988
Future Actions
The overall RI/FS for the San Gabriel Areas 1-4 sites is
currently underway. An initial phase of the remedial investigation/
the Supplemental Sampling Program/ was completed in 1986. The
workplan for the next phase of the RI/FS is currently being
developed. In addition/ the Region is examining alternative
approaches to completing the RI/FS and implementing remedial
actions in the San Gabriel Valley. It is currently estimated
that the RI/FS will take approximately 5 years to complete/ though
this is somewhat dependant on the overall approach that EPA takes
in completing the RI/FS.
-------
TABLE 1
SAN GABRIEL AREA 1
INITIAL REMEDIAL MEASURES
REVISED COST ESTIMATES OF ALTERNATIVES
Alternative
1.
2.
3.
4.
5.
Treat (fell Discharge with Air-Stripping System
A. Without Storage Reservoir
B. With Storage Reservoir
Treat Well Discharge with Carbon Adsorption System1
Connect to Metropolitan Water District
Join with Another Water Conpany
Bottled Water
Capital
Costs
($)
1,949,000
2,833,000
1,616,000-
1,772,000
2,135,000
202,000
-
5-Year
Operation &
Maintenance
($)
436,000
436,000
1,066,000-
1,148,000
75,000
10,459,000
5-Year Total
Increased 5-Year
Water Costs Costs
<$) ($)
2,385,000
3,269,000
2,743,000-
2,844,000
451,000 2,661,000
522,000 724,000
10,459,000
1) The range of cost figures represents the difference in total costs for all three nutuals depending on
which subaltentative method of upgrading Hemlock's existing carton adsorption system is implemented. The
total cost figure does not equal the sun of the ranges given for capital and O&M costs because the
Hemlock subalternatives with higher capital costs have lower O&M costs.
-------
TABLE 2
SAN GABRIEL AREA 1
INITIAL REMEDIAL MEASURES
SLMMARY OF ALTERNATIVES
alternative
Mr-Stripping
Public Health
Concerns
"emissions of PCB
to air leading to
a maximum indiv-
idual increased
cancer risk of up
to 6xlO-7
"would not be
effective if
other non-VOC
organics contam-
inate wells
•will not meet 10~6
cancer risk level
w/o system modifi-
cation/ or meet
action level if
concentration of
PCE rises above
design maximum
Environmental
Concerns
•would block con-
tinued migration
of contamination
•would emit PCE
removed from
water into air
(see public
health concerns)
Technical
Concerns
•proven technology
w/o storage res.;
•potential relia-
bility problems due
to excessive equip-
ment wear and oper-
ational complexity
Impact on
Community
•large increase
(140-180%) in
water bills of
mutual members
•high visual im-
pact in a resi-
dential neighbor-
hood
with storage res.: w/o storage res.;
•potential relia-
bility problems
reduced substan-
tially
•difficult to de-
sign and construct
due to anall areas
available for
construction
•potential noise
problems due to
24-hr, operation
•possible frequent
power surges &
disruptions due
to constant .
cycling of system
Other
•annual costs not
very sensitive to
level of contamin-
ation
•lowest annual
cost of all
alternatives
w/o storage res.;
•alternative with
2nd lowest over-
all cost
with storage res.;
•alternative with
2nd highest over-
all cost
In With
^>ther
i|>any
•would meet public "Does not control
state action level
of 4 ppb PCE, but
may not meet new
draft health
advisory for 10~"6
cancer risk for PCE
continued migra-
tion of contam-
inated ground
water
"Relies on simple
technology
•large increase
(170-220*) in
water bills of
mutual members
•requires perman-
ent irrevocable
dissolution of
mutuals
•alternative with
lowest overall
cost
•institutionally
infeasible as
mutuals will not
approve dissolu
tion
-------
tornatives
nnect to
iropolitan
ter
strict
Public Health
Concerns
"would meet
state action
level and
probably meet
new draft
health
advisory for
10~6 cancer risk
for PCE
TABLE °
(continu
SAN GABRIEL AREA 1
INITIAL REMEDIAL MEASURES
SUMMARY OP ALTERNATIVES
Environmental
Concerns
•does not control
continued migra-
tion of contam-
inated ground
water
Technical
Concerns
•relies on simple
technology
Impact on
Connunity
"large increase
(140-200%) in
water bills of
mutual members
"further increases
in water bills
likely due to
rising MM) water
costs
Other
"alternative with
3rd lowest overall
cost, however,
large uncertainty
in capital costs
"long implementa-
tion time
(> 1 year)
ttled
"mutual members
still potentially
ejqposed to PCE
during bathing
"does not control
continued migra-
tion of contam-
inated ground
water
"relies on simple
technology
"no increase in
cost of water to
mutual members
"inconvenience of
dealing with
bottled water
"alternative with
highest overall
cost (over 3 times
the cost of the
next highest cost
alternative)
Irbon "can effectively
borption treat contaminant
levels greater
than design con-
centration (w/
increase in
operating cost)
and can treat to
detection level
for PCE
•can effectively
remove other non-
VDC organics if
they contaminate
wells
"would block con-
tinued migration
of contamination
"some increased air
emissions at carbon
recycler's regener-
"proven technology
"difficult to de-
sign and construct
due to small areas
available for
construction, more
difficult than air-
stripping w/o
reservoir, less
than air-stripping
"meets SARA prefer-
ence for use of
treatment technol-
ogies by essentially with reservoir
destroying contamin-
ants trapped on
spent carbon during
regeneration
"no increase in
cost of water to
mutual members
"seme increase in
noise levels,
although less
than air-
stripping
alternative
"potential for
electrical surges,
though less than
air-stripping w/o
"alternative with
4th lowest overall
cost
"high annual oper-
ating costs .(only
annual cost of
bottled water is
higher
"annual operating
costs sensitive to
contaminant levels
-------
TKSLE 3
Ifanitoring Data for Rurfaan Heroes frfell NO. 2
STftTIO* ' FARAHE7ES l»8
3t8CHi-:c-:r^LtN= CMS
CMS
CDHS
:3HS
CSHS
CDHS
CIKS
CMS
CDHS
CWS
C3HS
CDHS
CDHS
:DHS
CMS
CDHS
CDHS
cws
C3*5
CWS
CSHS
CDHS
CMS
CMS
CMS
CDHS
CBHS
CMS
COHS
CWS
CBHS
CWS
COHS
CDHS
CMS
CDHS
CDHS
CMS
CMS
CMS
CMS
CMS
CMS
; s .
5
SMIL
ISMIk
1FSP4II
DATE
80.1). 31
8o::i.!<
91.01. 0?
81.01.12
81.02. 19
81.06.1?
81.07. IS
81.07.23
81.08.12
Bl.M.li
31.10.14
31.11.13
81.12.08
61.12.18
32.01.20
82.02.19
8:.OJ.il
82.03. ie
82.05.12
82.06. OE
82.06.17
82.06.18
82.06.23
82.06.30
82.07.07
82.07.14
82.07.23
82.08.03
82.08.17
82.00.22
82.04.30
82.10.27
82.11.22
82.12.22
82.12.29
83.02.16
83.04.07
83.05.17
83.08.1?
83.09.28
84.01.10
84.0i.l2
84.11.13
84.11.27
85.04. IS
87.01,2!
87.01.23
87 M Iff
WHLE
14.000C
it.OOGC
9.3000 '
».3000
8.:ooo
a.SC'OO
7.5WO
3. 3300
7.COOO
11.0000
1S.OOC.O
il.OOOO
5.3000
9.2000
i.9000
«.2000
6.7000
4.1000
3.300C
*.*OCd
7.3000 3
4.3000
4.0000
4.4000
4.7000
6.1000
4.6900 N
6.3000
6.4000
3.7000
3.9000
1.8000 1
0.4300
0.2200
0.2900
0.3100
1.8000
1.7000
2.4000
1.3000
1.0000
0.1000U
1.3000
1.7000
0.5000 U
0.5000 UD
0.5000 U9
faif»* »
WUWALY
UNITS ID
U6/L
JS/l
U6/L
i3/L
UB/u
yeyi
Uc/L
a/'.
US'L
UB/L
US/L
'J8/L
UO/L
U6-L
L£/L
U6/L
JS/L
li/u
t'S/L
'JS/L
US/L
US/L
Ufi/l
US/L
U6/L
US/L
U6/L
US/I
US/L
US/I
U6/L
U6/L
U6/L
J6/L
Ufi/L
U6/L
U6/L
U6/L
US/L
J6/L
U6/L
U5/L
U6/L
U6/1
'J6/L
lffi/L DUP 2
U6/L DUP 1
"i.v': .
-------
TABLE
Monitoring Data for Rurban Hones Vfell No.
STItlOH
LAB
CMS
CMS
COHS
CMS
CDHS
CMS
CDHS
CMS
CDHS
CMS
CMS
CMS
CMS
CMS
CMS
CMS
C3*S
CMS
CDHS
CWS
CHS
CDHS
CDHS
CMS
:»s
CMS
CMS
CMS
CONS
CMS
CMS
CMS
CMS
CMS
CMS
CMS
CMS
CMS
JW LAB
CMS
W.ESDA1L
TSUESMIL
-RUESMIL
TRUESOAIL
TRUESDAIL
DATE
80.10.31
80.11.14
81.01.0'
81.01.12 '
81.02.19
81.06.17
81. 07.15
81.07.23
a;. OB.;:
3i.uf.ii
31.10.14
81.11.18
91.12.08
31.12.16
E2.Oi.2C
92.02. C-«?
I2.:4.08
32.06.08
82.0i.l3
32.0i.*3
82.ftk.3C
82.57. i'
5-. -.1 «•
i.'." . »v
62.08.05
•2.08. T
52.01,30
52.;v.27
82.11. £
82.12.22
82.12.29
83.04.07
83.05.17
83.08.17
83. Of. 15
83.09.28
84.01.10
84.01.12
84.11.27
85.01.31
85.04.15
87.01.23
87.02.05
87.03.03
87.04.0!
87.05.04
VALUE
15.0000
20.0000
18.0000
19.0000
24.3000
11.0000
16.0000 '
19.0000
7.3000
11.0000
16.0000
11.0000
11.0000
I'.OOOO
25.4000
18.2000
36.0000
36.0000
38.0000
32.7000
33.4000
40.0000
35.7600
43. COCO
54.1000
45.0000
24.0000
12.3000
2.5000
4.2000
8.3000
3.7000
1.6000
0.1400
2.7000
2.1000
1.3000
6.6000
4.4000
0.1400
0.8800
0.8300
1.1400
0.6800
0.9400
AN3MU
UNITS ID
U6/L
US/L
n US/L
U6/L
U6/L
US/L
Ufi/L
UE/L
J6/L
IK/L
H US/L
US/t
U6/L
U6/L
3 U6/L
U6/L
Ui'l
US/L
U6/L
3 U6/L
u6/l
U6.L
US/L
US/L
US/L
US/I
US/L
J5/L
US/L
U6/L
U6/L
US/L
US/L
US/L
U6/L
US/L
US/I
1 U6/L
1 US/I
US/L
US/L
US/L
06/L
U5/L
US/L
-------
-58-
REFERENCES
CH2M Hill, 1983. Draft/ Focused Feasibility Study, San Gabriel,
prepared for the U.S. Environmental Protection Agency,
December 6, 1983.
CH2M Hill/ 1984. Discussion Draft, Predesign Study, Wellwater
Treatment"Facilities, IRM, San Gabriel Area 1, prepared
for the U.S. Environmental Protection Agency, September
28, 1984.
CH2M Hill, 1985a. South Coast Air Quality Management District
permit application for proposed air stripping facility
for Richwood Mutual Water Company, prepared for the
CJ.S. Environmental Protection Agency, August 30, 1985.
CH2M Hill, 1985b. South Coast Air Quality Management District
permit application for proposed air stripping facility
for Rurban Mutual Water Company, prepared for the U.S
Environmental Protection Agency, August 30, 1985.
CH2M Hill, 1986a. Draft Supplemental Sampling Program Report,
San Gabriel Basin, prepared for the U.S. Environmental
Protection Agency, May 19, 1986.
CH2M Hill, 1986b. Letter from Steven R. Conklin, CH2M Hill,
to Neil Ziemba, EPA, regarding cost estimates for air-
stripping systems,-prepared for the U.S. Environmental
Protection Agency, June 13, 1986.
CH2M Hill, 1986c. Final Draft, Predesign Memorandum for Richwood
Mutual Water Company Activated Carbon System, El Monte,
California, IRM, San Gabriel Area 1, prepared for the
U.S. Environmental Protection Agency, June 19, 1986.
CH2M Hill, 1986d. Final Draft, Predesign Memorandum for Rurban
Hones Mutual Water Company, Activated Carbon System,
El Monte, California, IRM, San Gabriel Area 1, prepared
for the U.S Environmental Protection Agency, June 19, 1986.
CH2M Hill, 1986e. Final Draft, Evaluation of Alternatives for
Hemlock Mutual Water Company Activated Carbon System
Expansion, El Monte, California, IRM, San Gabriel Area 1,
prepared for the U.S. Environmental Protection Agency,
June 19, 1986.
U.S. Environmental Protection Agency, 1984. Superfund Record of
Decision; San Gabriel Area 1 Site, CA, EPA ROD
R09-84-004, May 1984.
U.S. Environmental Protection Agency, 1985. Action Memorandum
and Revised Cost-Effectiveness Analysis of Alternatives
for the San Gabriel Area 1 Initial Remedial
August, 1985
-------
SAN GABRIEL AREA 1
Responsiveness Summary
Revised Cost-Effectiveness Analysis of Alternatives for the
San Gabriel Area 1 Initital Remedial Measures
Background
Large areas of the San Gabriel groundwater basin, Los Angeles
County/ California, have been found to be contaminated with
chlorinated hydrocarbons. San Gabriel Area 1, a plume of groundwater
contamination located primarily underneath the city of El Monte,
was included on EPA's final National Priorities List in May 1984.
In 1980, the State of California began an extensive well water
testing program in the San Gabriel basin which found numerous
wells contaminated with trichloroethylene (TCE), tetrachloroethylene
(PCE), and other chlorinated hydrocarbons. The California Department
of Health Services (OOHS) directed public water companies in the
area to periodically test their wells. State Action Levels for
TCE and PCE were set at 5 and 4 parts per billion (ppb), respectively,
based on the Environmental Protection Agency's (EPA) Suggested No
Adverse Response Level (SNARL). If alternative methods of reducing
PCE and TCE concentrations below the Action Levels (such as
blending waters from different wells) are not effective, wells
must be removed from service. In 1983, when EPA became involved
in addressing this problem, there were three mutual water companies—
Richwood, Rurban Homes, and Hemlock—that had no alternative
water supply and had been providing their customers with water
that is contaminated with PCE at concentrations above the OOHS
Action Level.
In May 1983, a management committee comprised of EPA, various
state and local agencies, and representatives of various water
companies and public interest organizations was established with
California DOBS as its chair. The objectives of this committee
are: 1) to find a solution for the three mutual water companies
that have a well contamination problem and have no alternative
water supply; 2) to identify and control any TCE/PCE sources; and
3) to develop an overall strategy for management of the plume
areas.
To address this first objective, EPA directed its contractor,
CH2M Hill, to evaluate alternative initial remedial measures (IRM)
to solve the mutuals1 water contamination problems during the
interim period before a final long-term solution to groundwater
contamination in the San Gabriel basin is implemented. This
evaluation was summarized in a Focused Feasibility Study dated
December 6, 1983.
-------
-2-
The Focused Feasibility Study (FFS) identified several
feasible alternatives to solve the mutuals' problems. After a
formal public comment period and a public meeting to which all
members of .the mutuals were invited, Region 9's Regional
Administrator signed a Record of Decision on May 11, 1984 selecting
air-stripping treatment as the cost-effective initial remedial
measures (IRM) for San Gabriel Area 1. Two alternatives that
were technically feasible and lower in cost than air-stripping
were not selected as the cost-effective IRM due to institutional
problems. The lowest cost alternative, under which the mutuals •
would obtain water from a nearby water company while leasing
their water rights, was not selected because no nearby water
company was identified which would agree to provide water under
such an arrangement. The next lowest cost alternative was for
the mutuals to dissolve as independent water companies and join a
nearby water company. This alternative was not selected after
the membership of each mutual voted not to dissolve.
After the Record of Decision was signed, EPA issued a work
assignment to its contractor, Cf^M Hill, to design air-stripping
treatment systems for the Richwood and Rurban Homes Mutual Water
Companies. The third mutual, Hemlock, declined to have an air-
stripping system provided as an IRM and has instead purchased and
installed its own carbon adsorption system. In June of 1984, the
design team from CH2M Hill visited the mutuals' well sites to
obtain background information on the present water systems'
operating characteristics and to obtain water samples for full
organic priority pollutant analysis. The purpose of the water
analyses was to confirm that the only contaminants present were
volatile organics which could be treated with an air-stripping
system. The results of these analyses confirmed that PCE was the
only contaminant present in the mutuals' well water at levels of
concern.
After the initial site visit, CH2M Hill recommended the
preparation of a Pre-Design Study of air-stripping systems for
the Richwood and Rurban Homes mutuals. The site visit had
identified several severe constraints that would be imposed on the
system design due to the limited site area, high peak water flows
in the systems, close proximity to neighbors at the well sites,
and the need to design a system which the mutuals could operate
reliably (since the California Department of Health Services
(DHS) at that time planned to require the mutuals to be responsible
for system operation and maintenance). The purpose of the Pre-Design
Study was to investigate different configurations of air-stripping
systems to determine the most cost-effective and reliable
configuration before proceeding with the final system design.
EPA authorized CH2M Hill to begin this study in July 1984.
-------
-3-
The Pre-Design Study examined two possible configurations of
an air-stripping system -- one with and one without a 60,000
gallon storage reservoir. The addition of a storage reservoir
would allow the treatment system to operate more continuously
during the day and would be more reliable. When it became clear
that the cost of designing and constructing air-stripping systems
would be much higher than those identified in the December 1963
Focused Feasibility Study/ EPA also reevaluated the carbon adsorption
alternative in the Pre-Design Study. This alternative had previously
been determined to be effective in solving the mutuals1 problems.
Based on the results of the Pre-Design Study/ EPA determined
that the air-stripping system configuration without the 60/000
gallon storage reservoir was not cost-effective due primarily to
potential problems with system reliability. Moreover/ this
system would potentially have adverse impacts on the local community/
such as possible noise problems associated with its 24-hour
operation in a residential neighborhood. The cost of including a
storage reservoir in the air-stripping system/ however/ made the
total 5-year costs for air-stripping and carbon adsorption virtually
equal. Therefore, either treatment system alternative appeared
to be potentially cost-effective. The only significant difference
in cost is that air-stripping has a much higher capital cost than
carbon adsorption/ but significantly lower operation and maintenance
(O&M) costs. This fact is important since/ at that time/ DHS
planned to require the mutuals to pay for long-term O&M costs.
EPA and DHS met with the board of directors of Richwood and
Rurban Homes to discuss the results of the Pre-Design Study.
Because the mutuals' shareholders were not able to pay for the
O&M costs of a carbon adsorption system/ EPA decided to continue
with the design of air-stripping systems that now included the
60/000 gallon storage reservoirs. EPA prepared conceptual designs
for the treatment systems/ and in September 1985/ Richwood and
Rurban Homes filed permit applications with the South Coast Air
Quality Management District to construct air-stripping facilities.
When EEA became aware that the cost of carbon adsorption systems
would be comparable to the cost of air-stripping systems/ a
reevaluation of Hemlock's situation was included in the Pre-Design
Study. Hemlock had declined to participate in the IRM project
when air-stripping was selected by EPA as the most cost-effective
alternative. Instead/ they had purchased and installed a carbon
adsorption system to treat their drinking water. While pilot
tests had shown that their system would adequately treat the
contaminated water from their wells/ their system was not designed
with the same design criteria proposed by EPA for Richwood and
Rurban Homes in the Pre-Design Study. In addition/ DHS required
Hemlock to install a flow restrictor on their water system to
ensure adequate treatment of their well water. The flow restrictor
limited the rate at which well water could be treated by the
carbon adsorption system and could possibly cause problems with
-------
-4-
low water pressure in the systems at times of peak water use.
Therefore, as part of the Pre-Design Study, EPA evaluated the
feasibility and costs of improving Hemlock's treatment system to
meet the design criteria used for evaluating carbon adsorption
systems for the other mutuals. This evaluation showed that
installing an upgrade to Hemlock's system was now cost-effective
in comparison to air-stripping. In November 1984, EPA notified
Hemlock's board of of directors that an upgrade to their existing
treatment system could be considered as part of the IRN if Hemlock
agreed to pay operating costs incurred by the improved system.
Hemlock notified EPA that it still did not wish to participate in
the IRM project.
In August of 1985, the California State Assembly began
considering Senate Bill 1063 (SB 1063) that would authorize State
funding for design and construction of carbon treatment systems
for Richwood and Rurban Homes, as well as an upgrade to Hemlock's
existing carbon adsorption system. The most important feature of
SB 1063 was that it directed OHS to pay for O&M for the carbon
adsorption systems for 20 years, which is the design life of the
treatment systems. The bill was passed by the legislature and
became law in October 1985.
In February 1986, DHS informed EPA that it was prepared to
implement the provisions of SB 1063 including the payment for O&M
on the three carbon adsorption systems. This recent development
allowed EPA to reconsider its initial selection of air-stripping
systems, since it was the mutuals1 inability to pay for carbon
adsorption O&M costs that led EPA to continue the design of air-
stripping systems despite the results of the September 1984 Pre-
Design Study. EPA has now prepared conceptual designs and cost
estimates for carbon adsorption systems for Richwood and Rurban
Homes, and for several different ways of upgrading Hemlock's
existing carbon adsorption system.
Based on the new information regarding the costs of air-
stripping and carbon adsorption systems, EPA prepared a draft
report, "Revised Cost-Effectiveness Analysis of Alternatives for
the San Gabriel Area 1 Initial Remedial Measures." This report
proposed that EPA revise its previous decision selecting air-stripping
as the cost-effective alternative for the San Gabriel Area 1
Initial Remedial Measures and now select carbon adsorption as the
cost-effective IRM alternative. In October 1986, EPA released
this draft report for public review and comment. A fact sheet
that summarized the report and EPA's proposed action was prepared
and distributed to everyone on the San Gabriel sites mailing list.
In addition, EPA provided the three mutuals with copies of the
fact sheet for distribution to their shareholders. Copies of the
report were distributed to California OHS and directly to the
three mutual water companies affected. The report was made
available at three information repositories that had been previously
established for this project: 1} El Monte Public Library in El
Monte; 2) Norwood Public Library in El Monte; and 3) EPA Region 9
-------
-5-
Office in San Francisco. The fact sheet that was distributed
announced the availability of the report/ the location of the
information repositories/ and the scheduled public comment period
which ran from October 10, 1986 to October 31, 1986.
A public meeting was not scheduled during the public comment
period. It was felt that the interest level in this proposed
action did not warrant a public meeting. Less than ten members
of the public attended the December 19, 1983 public meeting that
was held to accept comments on the December 1983 Focused Feasibility
Study. No individuals in attendance at that meeting chose to
make an oral statement or to submit written comments at that
time. Only two public comments were submitted during the December
1983 public comment period. In addition to the lack of interest
in EPA's proposed project in the past, it was also known from
meetings with the mutuals' board members that the mutuals supported
EPA's proposed change of selection of, remedy for the IRM.
Therefore, it was decided to forego the scheduling of a public
meeting unless requests for such a meeting were obtained for the
public—no such requests were received. EPA did offer to schedule
a meeting for the mutual members upon request.
EPA received two written comments during the public comment
period. A list of commentors is included at the end of this document
and copies of the written statements are attached.
Comments
In terms of which alternative initial remedial measure was
supported, the two comments received can be summarized as follows;
a later section will discuss specific comments regarding the
revised cost-effectiveness analysis.
One commentor supported the selection of the alternative under
which the mutuals would dissolve and join another water company
as the most cost-effective alternative; and
One cootaentor, while stating a preference for the carbon
adsorption alternative, believes that air-stripping treatment is the
most cost-effective alternative.
Response
It is the recommendation of EPA and the California Department
of Health Services (DHS) that the previous decision selecting treatment
of contaminated water with air-stripping systems be revised to provide
for treatment of contaminated water with carbon adsorption systems
for Richwood and Rurban Homes Mutual Water Companies and to
provide for an upgrade, if necessary, to Hemlock Mutual Water
Company's present carbon adsorption system.
-------
-6-
As wag discussed in the May 1984 Record of Decision/ although
it is lower in cost than treatment alternatives, joining with
another water system would require dissolution of the mutuals by
a shareholders' vote. After meetings with the mutuals to discuss
this alternative/ each mutual voted against dissolution and joining
with another water company. Moreover, implementing this alternative
without the mutuals1 consent would necessitate condemning their
water rights/ which would significantly increase the cost of this
alternative. Therefore/ as in the May 1984 Record of Decision/
EPA and DBS are not recommending implementing this alternative.
Although/ the revised cost-effectiveness analysis confirms that
the air-stripping alternative (that does not include installation
of an in-ground storage reservoir) has a lower 5-year present
worth cost than carbon adsorption/ the carbon adsorption alternative
has several non-cost advantages over the air-stripping alternative.
In addition/ the carbon adsorption systems described in the reviser*
cost-effectiveness analysis can easily treat down to the detection
limit (1 ppb) of PCE which approaches the EPA drinking water
health advisory 10~6 cancer risk level (0.7 ppb) for PCE with
little added cost. The air-stripping systems would have to be
designed with approximately 15-20 additional feet of packing and
would also require an increase in the operating air flow of up to
20%. This would significantly increase the cost of the air-stripping
alternative. Also/ the carbon adsorption system with regeneration
of the spent carbon meets the preference of the Superfund Amendments
and Reauthorization Act of 1986 (SARA) of using treatment technologies
that significantly and permanently reduces the volume/ toxicity/
or mobility of the waste to the maximum extent practicable by
incinerating the contaminants trapped on the spent carbon.
Conversely/ the air-stripping alternative just transfers the
contaminants to the air with dilution leading to an increased
public health risk due to the air emissions. Based on these
other non-cost factors/ EPA and DHS have determined that carbon
adsorption is the cost-effective alternative that best protects
public health and the environment through balancing of cost and
non-cost factors.
Specific Comments and Responses
In addition to the major comments reviewed above/ other
specific comments were received as follows:
0 One commentor stated that in considering the alternatives/
subsequent costs as well as potential air pollution problems
should be considered/ specifically problems relating to spent
carbon transfer and disposal.
Commentor is correct in stating that subsequent costs/ as
well as other environmental effects such as air polluti
• impact? should be
-------
-7-
incineration for reuse rather than disposed of in a
landfill. There may be a small increase in air emissions
at the recyclers1 regeneration facility associated with
the regeneration ofthe spent carbon, however, the amount of
emissions would be less than that associated with the
air-stripping alternative since the thermal regeneration
process would incinerate most of the contaminants adsorbed
to the spent carbon. The cost estimate for replacing
spent carbon assumed a $1.00/pound charge for virgin carbon,
plus a $0.50/pound charge for freight, carbon removal and
replacement in the vessels, hauling away, and disposal. It
is assumed that for a fee the carbon supplier would provide
virgin carbon for use in the mutuals* treatment systems
and would take possession of the spent carbon for regeneration
at their own facility. Requiring regeneration of the
spent carbon is consistent with the SARA preference for
the use of treatment technologies that significantly and
permanently reduces the volume* toxicity, or mobility of
the waste to the maximum extent practicable, as well as
the SARA designation of land disposal of untreated hazardous
waste as the least-preferred cleanup option.
0 One commentor noted that regarding the use of available
space, the air-stripping towers are 5 feet in diameter and
the carbon vessel is ten feet in diameter.
This comment, as related to the constraints posed on system
installation is correct. The revised cost-effectiveness
analysis was in error in stating that it will be more difficult
to construct air-stripping systems than carbon adsorption
systems. In the 1984 Pre-Design Study this was thought to
be the case. Now that more detailed conceptual designs
have been prepared for both treatment systems, it appears
that based on the expected dimensions of the air-stripping
towers and carbon vessels required, it will be more difficult
to handle and place carbon vessels on the sites. However,
it would be more difficult to design and construct the air-
stripping system if the installation of an in-ground
storage reservoir is included because of the large excavation
project involved in constructing that alternative.
0 One commentor stated that the addition of a reservoir in
one of the air-stripping system alternatives and inclusion
of its cost in the cost-effectiveness analysis is questionable.
A similar reservoir could be required for the carbon
adsorption system since replacement and maintenance of. pumps
are involved in both systems. The commentor stated that
the cost of a reservoir should be included in both treatment
systems or not at all.
In the 1984 Pre-Design Study, the installation of a storage
reservoir along with the air-stripping system was considered
due to the complexity of the control system that would be
required to have the well pump and booster pumps cycle on in1
-------
-8-
off continuously. The inclusion of a storage reservoir
for added "system reliability" was strongly influenced by
the fact that operation of the air-stripping system was to
be the responsibility of the mutuals (in accordance with
DBS policy at that time), which had no experience in
operating a complex water treatment system. At that time,
it was assumed that the well pumps had the capacity to pump
water through a carbon adsorption system and still maintain
adequate pressure in the system. More recently, in preparing
the conceptual designs for the carbon adsorption systems,
it has been determined that it would be prudent to include
booster pumps in the design due to the high head losses
associated with the carbon vessels and the fact that the
actual head and capacity of the mutuals existing pumps are
nor known. However, under Senate Bill 1063, DBS will
operate and maintain carbon adsorption systems for the
mutuals. DHS has informed EPA in writing that it is
committed to implementing Senate Bill 1063. Therefore,
the need to simplify the complexity of the carbon adsorption
system to increase "system reliability" is not as great
since the mutuals will not be operating the systems themselves.
Consequently, the carbon adsorption system does not requir*
the installation of a large storage reservoir for each of
the mutuals. In comparing the alternatives, air-stripping
with and without the storage reservoir is considered.
0 One commentor questioned the statement that operation of
the air-stripping system may cause electrical surges due
to system cycling and noted that the power difference
between air-stripping and carbon adsorption would be
approximately 50 Horsepower (141.5 Horsepower for air-
stripping as compared to 95 Horsepower for carbon adsorption).
As previously discussed, during the 1984 Pre-Design Study
it was assumed that booster pumps would not be required for
the carbon adsorption system. Now that they are included
in the current carbon adsorption system conceptual design,
there will be a cycling of electrical equipment similar to
that, associated with the air-stripping system (without a
storage reservoir). However, the power load will be
approximately doubled in the air-stripping system as
compared to the carbon adsorption system (141.5 Horsepower
as compared to 75 Horsepower). [Note: One 20 Horsepower
booster pump is strictly a backup pump in the carbon
adsorption system design, and therefore, the total power
load in 75 Horsepower not 95 as stated by the commentor.]
When comparing the projected power loads to the current
power requirements of the existing wells, the carbon adsorptii
system will involve less than a 36% increase in power load,
while the power load for an air-stripping system will
result in an increase of over 150% from current power
-------
-9-
requirements. It cannot be determined whether this added
power load will cause surging on the power lines without a
detailed evaluation based on information from the local
power company and an analysis of the motor starting
characteristics of the existing and proposed equipment.
An air-stripping system, however, would have a higher
probability of causing such surges due to the greater
increase in cycling power load.
0 One commentor notes that the operation and maintenance
(O&M) costs associated with carbon adsorption are many
times higher than that associated with air-stripping.
In addition, the commentor questions the use of a 5-year
operating cycle.
We agree that the O&M cost for the carbon adsorption
alternative is much higher than that associated with air-
stripping. The primary reason is the cost of replacing
spent carbon. Carbon replacement costs were estimated at
$1.50 per pound, based on $1.00 per pound of virgin carbon,
plus $0.50 per pound for freight, carbon removal and
replacement in the vessels, hauling away, and disposal.
Other O&M costs include power costs (higher for air-stripping
due to greater power usage), maintenance costs (estimated
to be one third higher for air-stripping because of extra
pumps and blowers), and sampling and analysis costs
(essentially the same for both treatment alternatives).
Regarding the use of a 5-year operating cycle in the
present worth analysis, as stated in both the May 1984
Record of Decision and the Revised Cost-Effectiveness
Analysis, 5 years was used since the primary objective of
the initial remedial measures is to take action to provide
clean water during the interim period before a final
remedial action is in place. When a final remedial action
is chosen for San Gabriel Area 1, it may entail abandoning
the use of the mutuals wells. Therefore, it is considered
appropriate to use the 5-year operating cycle in the cost-
effectiveness analysis.
0 One counentor stated that the diameter of the carbon
vessels whould be increased from the proposed 10 feet or
additional vessels provided, in order to decrease the
surface loading rate from the planned 11.2 gpm/ft2 to
below the 5 gpm/ft2 the literature indicates is an acceptable
maximum for pressure vessels. This would entail additional
equipment costs that should be included in the cost estimate
for the carbon adsorption system.
We are in agreement that 5 gpm/ft2 is a desirable surface
loading rate. For Richwood and Rurban Homes/ the .surface
loading rate at the annual average flow is 2.7 gpm/ft2. As
this implies, this is the average loading rate throughout
-------
-10-
the year. Peak flows of 2-3 times the average flow can be
expected on a daily basis for short periods of time in the
morning and evening. This will result in short-term
surface loading rates of 5.4 to 8.1 gpm/ft2. Summer
seasonal peaks of 4 times average flow may occur on the
hottest days of the year. At these infrequent times/ the
surface loading rate in the carbon vessels may reach 10 to
11 gpm/ft2. As the surface loading rate of 10 to 11
gpm/ft2 occurs very infrequently, it is considered acceptable.
It would not be cost-effective to design the carbon vessels
to provide a surface loading rate of 5 gpm/ft2 for flows
of 4 times the average flow.
9 One commentor noted that the costs of carbon adsorption
versus air-stripping show that the latter has appreciable
cost advantages/ and that data from EPA's Drinking Hater
Research Division in Cincinnati/ Ohio confirms this.
We agree with the commentor that air-stripping without the
storage reservoir has a cost advantage over carbon adsorption,
particularly as regards operation and maintenance costs.
The air-stripping alternative that does not include the
storage reservoir/ however./ would be operated by the
mutuals themselves. The complexity of the systems and the
mutuals' inexperience in operating complex water treatment
systems leads to serious concerns regarding the systems'
reliability. Therefore/ EPA and DHS have decided that in
this specific application/ the non-cost advantages of
carbon adsorption outweigh the cost advantage of air-stripping
and better meet the goals of SARA as the overall cost-
effective remedial action alternative.
Response From the Mutuals
As discussed earlier/ EPA provided each mutual with a copy
of the revised cost-effectiveness analysis and provided fact
sheets describing the study to the mutuals for distribution to
their shareholders. EPA asked the mutuals to respond to EPA with
their preferences regarding the alternative initial remedial
measures. Both Richwood and Rurban Homes Mutual Water Companies
provided letters to EPA stating that they were in agreement with
the EPA proposal to revise the selection of alternative for the
San Gabriel Area 1 initial remedial measures from air-stripping
to carbon adsorption treatment systems. The president of Hemlock
Mutual Water Company advised EPA that the Hemlock board of
directors had decided not to request that the proposed upgrade to
their carbon adsorption system be implemented/ and therefore/
requested that they not be included in the initial remedial
measures project at this time.
-------
-11-
New Information
Since the October 1986 public comment period on EPA's revised
cost-effectiveness analysis/ sampling of Rurban Homes' wells has
shown a reduction in contaminant levels. The last time Rurban
Homes' wells were sampled (1/31/85) before the October 1986
public comment period/ Well No. 1 showed a PCE concentration
of 4.4 ppb/ just above the OHS action level. This well has had a
maximum PCE concentration of 54 ppb in the past. Since the
public comment period/ the wells have been sampled monthly for
the first five months of 1987 as part of the Assembly Bill 1803
sampling program currently being conducted by the Main San Gabriel
Basin Watermaster. PCE has not been detected at all in Well No.
2 in 1987. The laboratory has reported values of PCE of 0.68 -
1.14 ppb in Well No. 1 in five samples collected in 1987. This
is essentially the limit of quantification for PCE analysis.
At this stage in the San Gabriel RI/FS/ the knowledge of the
sources/ extent/ and character of the groundwater contamination
is not detailed enough to determine the reason for this drop in
contamination levels. The influence of other wells pumping in
the vicinity or changing water levels may have affected contaminant
migration/ or a slug of contamination may have passed through the
Rurban Homes well field.
Decision Summary
After consideration of the public comments received and the
preferences shown by the three mutuals/ EPA and OHS have decided
to revise the alternative selection for the San Gabriel Area 1
initial remedial measures from air-stripping treatment systems to
carbon adsorption systems. A Carbon adsorption system will be
installed at the Richwood Mutual Water Company.
Although Hemlock Mutual Water Company advised EPA that it
did not wish the upgrade of its carbon adsorption system to be
implemented at this time/ EPA and DHS have decided to still
select the upgrade to Hemlock's present carbon adsorption system
as the revised initial remedial measure alternative. This will
allow EPA and OHS to take action in the future to upgrade Hemlock's
treatment system if Hemlock's present carbon system begins to
have problems without having to go through another remedy selection
process.
For Rurban Homes Mutual Water Company/ EPA and DHS have .
decided not to implement initial remedial measures at this time
since the contaminant levels have remained steady at the levels
recommended as the public health goal for the IRM through the
first half of 1987. The design and preparation of bid documents
for the IRM for Rurban Homes/ however/ will be completed at this
time. This will allow EPA and DHS to take immediate action to
-------
-12-
protect public health if regular monitoring shows the contaminant
levels increasing again or if other investigations determine that
upgradient contamination threatens the wells. This approach has
been discussed with the President of the Rurban Homes Board of
Directors/ who had no objections to this approach and informed
the other members of the Board of Directors.
List of Commentors
0 R. F. Gruszka, Vice President; Southern California Water Company/-
letter dated October 1, 1986.
0 Sanford N. Weiss, Director of Engineering; and George Ames/ A.Q.
Engineer II; South Coast Air Quality Management District; letter
dated November 4, 1986.
List of Responses from Mutuals
• Bonnie Pool/ Secretary/Treasurer; Richwood Mutual Water Company;
letter dated November 2, 1986.
• George W. Bucey, President; Don Sagar/ Vice-President; Dick
Sardeson, Engineer; Mike Cox/ 2nd Vice-President; and John
MeKenna/ Plant Manager; Rurban Homes Mutual Water Company;
letter dated October 31, 1986.
0 Bud Selander/ President/ Hemlock Mutual Water Company; Record of
Communication summarizing phone conversation/ November 5/ 1986.
------- |