SFUND RECORDS CTR1652-04013

United States Environmental Protection AgencyRegion 9 AR0088

In the Matter of :

Iron Mountain Mine

Iron Mountain Mines, Inc.,T.W. Arman,Rhone-Poulenc Basic Chemicals Co.

First Amendment toOrder No. 94-12

Respondents

Proceeding under Section 106 of theComprehensive Environmental Response,Compensation and Liability Act of 1980,as amended by the Superfund Amendmentsand Reauthorization Act of 1986,(42 U.S.C. § 9606)

FIRST AMENDMENT TO ORDER NO. 94-12

1. This First Amendment to Order No. 94-12 is issued to

Respondents by the United States Environmental Protection Agency

("EPA") under the authority of section 106 (a) of the Comprehensive

Environmental Response, Compensation, and Liability Act of 1980,

as amended ("CERCLA"). This authority was delegated to the

Administrator of EPA on January 23, 1987, by Executive Order 12580

(52 Fed. Reg. 2926, January 29, 1987), and was further delegated

to EPA Regional Administrators on September 13, 1987 by EPA

Delegation No. 14-14-B. The Regional Administrator redelegated

this authority to the Director, Superfund Division. Except as

specified herein, this action does not alter any of the deadlines

or obligations in Order 94-12 or any other order issued by EPA in

connection with the Iron Mountain Mine Superfund Site.

2. Unless otherwise specified, defined terms in this First

Amendment shall be the same as the terms as defined in

Order 94-12.

I. FINDINGS OF FACT AND CONCLUSIONS OF LAW

3. Except as modified herein, this Amendment is based upon the

Findings of Fact contained in Order Nos. 93-01 (as amended) and

94-12 and the Conclusions of Law of contained in Order 94-12.

4. On September 30, 1992, EPA signed a Record of

Decision ("ROD2") that selected, among other things, treatment of

the Acid Mine Drainage ("AMD") discharges from the Richmond and

Lawson adits utilizing the lime/sulfide High Density Sludge

("HDS") treatment method.

5. On September 24, 1993, EPA signed a Record of

Decision ("ROD3") that selected, among other things, treatment of

the AMD flows from the Old/No. 8 Mine Seep utilizing the lime HDS

treatment method.

6. EPA selected HDS treatment as the method of treatment for

several reasons, including but not limited to:

a. EPA studies and research indicated that HDS sludge would

be chemically and physically more stable than simple mix sludge.

EPA tests on treated sludge showed that, compared to sludge

generated by simple mix, HDS sludge is more effective in binding

the metals in the sludge.

b. EPA studies and research indicated that HDS sludge would

have drainage characteristics that are superior to simple mix

sludge. Improved drainage characteristics will enable sludge to

dewater more effectively in the sludge drying beds at the

treatment plant and improve plant reliability.

c. EPA studies and research indicated that HDS sludge would

have superior physical and handling characteristics and would be

more manageable than simple mix sludge. These superior physical

characteristics would allow for adequate long term management of

the sludge disposal area, Brick Flat Pit ("BFP") .

d. EPA studies and research indicated that HDS sludge would

be more dense and would take up less volume than simple mix

sludge. This greater bulk density would extend the useful life of

the sludge disposal site at BFP significantly. EPA estimated that

compared to simple mix, treatment using the HDS method would

double the useful life of BFP.

e. EPA also determined that HDS treatment would be more

cost effective than simple mix treatment at the Minnesota Flats

plant site.

7. On November 3, 1993,- EPA issued Order 93-01 to Respondents

which required Respondents to, among other things, design and

construct an HDS treatment plant.

8. Rhone-Poulenc resisted construction of an HDS plant on the

ground that the aerated simple mix ("ASM") treatment method was

comparable to the HDS treatment method with respect to sludge

reduction, physical/handling characteristics and compliance with

other CERCLA requirements. EPA disagreed with Rhone-Poulenc's

technical position, but in order to expedite completion of a

treatment plant at Minnesota Flats, EPA agreed to take

responsibility for designing and constructing the HDS components

at the Site, provided that Rhone-Poulenc expeditiously design and

construct the simple mix components that complement the HDS

components to be constructed by EPA. EPA reserved all its rights

to seek recovery of its costs. On October 8, 1993, EPA amended

Order 93-01 to suspend the obligation of Rhone-Poulenc to

construct the HDS treatment components under Order 93-01.

9. On April 19, 1994, EPA issued Order 94-12 which required

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Respondents to, among other things, collect, convey and treat all

acid mine drainage from the Richmond and Lawson Portals and the

Old Mine/No. 8 Seep and dispose of the treatment residue in BFP in

accordance the EPA approved Operation & Maintenance Plan.

10. Pursuant to Order 93-01, as amended, and Order 94-12 Rhone-

Poulenc constructed AMD collection and conveyance facilities,and

the ASM treatment plant components at Minnesota Flats.

11. Since approximately October 1994, Rhone-Poulenc has operated

the ASM treatment plant pursuant to Order 94-12.

12. Information obtained by EPA since it issued ROD2 and RODS,

including but not limited to design studies, actual data from the

existing treatment plant, and investigation of ASM plant

operations, has reinforced the superiority of the HDS system and

the deficiencies of using an ASM system to address the release and

threat of release hazardous substances at the Site.

13. The ASM plant has failed to produce a sludge that is

comparable to the sludge EPA anticipates the HDS method would

produce. The sludge produced by the ASM process has a high water

content, low density, and extremely poor handling characteristics.

Data provided by Rhone-Poulenc show that ASM sludge hauled from

the sludge drying beds to Brick Flat Pit has an average solids

content of less than 40%. EPA anticipates that a properly

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operated HDS plant will generate a sludge with a solids content

between 60% and 65%. EPA estimates that an increase in solids

content from 40% to 60% would correspond to a volume reduction of

50%.

14. The ASM plant is replete with inherent operational

difficulties and other deficiencies. These problems make the

existing plant an unreliable and potentially unsafe manner to

respond to the releases or threats of releases from the Site that

may pose an imminent and substantial endangerment to public

health, welfare or the environment. The HDS treatment method

would eliminate or substantially reduce these difficulties and

deficiencies.

15. The HDS treatment method would also be more cost effective

than the existing ASM treatment method.

16. EPA's selection of the HDS treatment method was fully

consistent with the National Contingency Plan, 40 CFR § 300 et

seq.

17. The existing sludge drying beds were designed for HDS and are

too small to store all of the ASM sludge generated in a major

storm event. During the January 1995 storm event, the sludge

drying beds became full. A spill of untreated AMD from the

treatment plant was avoided only through the combination of

significant effort, considerable extra cost, and the fortuitous

presence of a large construction cadre on-site at the time.

18. Although Rhone-Poulenc has constructed one additional drying

bed since the 1994-1995 wet season, that bed is currently

unavailable to store ASM sludge. Due to the poor drainage

characteristics of the ASM sludge, the ASM sludge blinds off the

sand filters in the drying beds. As a result, unfiltered leachate

ponds at the top of the drying beds. Because the leachate must be

filtered prior to being discharged into Spring Creek, Rhone-

Poulenc currently uses the newer drying bed solely to filter the

leachate that ponds in the other three drying beds.

19. Rhone-Poulenc has regularly ripped the geotextile liner and

the geotextile grid when Rhone-Poulenc is removing the ASM sludge

from the drying beds. Destruction of or damage to the geotextile

liner increases the risk that unfiltered leachate will be released

into Spring Creek and Flat Creek. These rips threatened to cause,

or may have caused, the release of leachate into the environment.

20. Contaminated water has been detected adjacent to and

downgradient from the drying beds. The constituents and location

of the contamination indicate that the contamination may have been

caused in whole or in part by a leak in the liner. The

contaminated water flows into Flat Creek, upstream of residents

who use the water of Flat Creek for agricultural irrigation.

21. Future operation of the ASM treatment plant threatens to

cause similar rips and similar threatened or actual releases of

leachate because the ASM treatment method can require winter

sludge hauls due to the large volume that is generated. These

winter hauls threaten the integrity of the sludge drying bed

liners. Poor weather creates difficult working conditions.

Hauling in the winter does not permit sufficient drying time for

dewatering. The poor handling characteristics of the dewatered

ASM sludges, and the difficult working conditions in the drying

beds significantly increases the likelihood that sludge excavation

operations would damage the drying bed filter and lining system.

As discussed above, this damage may result in the release of

contaminants into the environment.

22. Using the HDS treatment method would reduce substantially the

likelihood of a liner tear and a release of leachate. Since HDS

will create a higher density sludge, sludge hauling will, in all

but the most extreme years, be required only once a year -- in the

summer. In the event of a liner tear during HDS operation, the

leachate from HDS sludge would pose less of a threat to public

health and the environment than leachate from ASM sludge because

the HDS leachate will be less voluminous than the ASM leachate.

23. The ASM sludge is thixotropic and does not allow for an

engineered and stable fill. The continued dumping of ASM sludge

threatens to make BFP unsafe and potentially unusable without

expensive corrective measures. The ASM sludge has blinded off and

clogged the bed-drainage system in BFP and threatens to clog the

few remaining column filter drains in BFP. Without adequate

drainage, BFP will become unmanageable and may have to be

abandoned well before its full capacity is realized.

24. Due to the poor handling characteristics of the ASM sludge,

there are very few options for managing the sludge. None of the

available options allow for the creation of a stable landfill.

Because the ASM sludges could not be placed as an engineered fill

in BFP, until recently, Rhone-Poulenc transported the ASM sludge

to a bluff above the eastern side of BFP and then dumped the ASM

sludge down a slope and into BFP. The bluff, and slope below the

bluff, have failed, so that this procedure can no longer be used.

Because ASM sludge is difficult to handle, Rhone-Poulenc is now

dumping the ASM sludge directly onto the edge of the BFP liner at

the west end of the pit. EPA is unaware of any engineering work

that demonstrates that the anchors for the liners were adequately

engineered for this purpose. If the liner is not properly

engineered, repeatedly dumping the sludge directly onto the edge

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of the liner would threaten to rip the liner and cause a release

of leachate into the environment.

25. EPA studies indicate that the HDS sludge will have a

granular, soil-like consistency. This improved consistency will

allow for the management of BFP as an engineered landfill. This

improved consistency will also result in a sludge that will have

drainage characteristics that are superior to the ASM sludge. The

improved drainage characteristics will enable the landfill to

drain properly and allow BFP to be managed as a dry landfill.

26. Experience with the ASM treatment plant also confirms EPA's

conclusion that the HDS treatment method is more cost effective

than the ASM treatment method. The ASM treatment method generates

a much larger volume of sludge than the HDS treatment method, so

the cost of hauling sludge generated by the ASM method is

proportionally much greater than the cost of hauling sludge

generated by the HDS method. In addition, the unit cost of

hauling HDS sludge will be lower than ASM sludge. First, due to

its lower volume, HDS sludge will only need to be hauled in the

summer, when haul rates will be lower. Second, HDS has superior

handling characteristics so it will be easier (and less expensive)

to haul. While HDS could have slightly higher utility and

maintenance costs, those costs will generally be more than offset

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by the lower haul costs associated with the HDS process.

27. EPA has designed and constructed improvements to the

treatment plant that will enable the treatment plant to treat AMD

using the HDS treatment method. Throughout the design and

construction of these improvements, EPA has kept Rhone-Poulenc

fully informed of its activities and has sought input from Rhone-

Poulenc on the project. During the tie-in of the HDS improvements

to the existing treatment facility, EPA carefully coordinated its

construction activities with Rhone-Poulenc representatives. EPA

has also provided early drafts of operation and maintenance

manuals to Rhone-Poulenc and requested comments on these drafts.

EPA understands that Rhone-Poulenc representatives are currently

using the manuals provided by EPA to train the operators of the

ASM treatment plant for HDS operation. EPA has coordinated and

sponsored training of Rhone-Poulenc personnel on the start-up,

operation and maintenance of the HDS improvements.

28. The HDS treatment plant is scheduled to begin operation on

January 7, 1997.

29. The actions required by this First Amendment to Order No. 94-

12 are necessary to protect the public health or the environment.

The response action was selected in ROD2 and ROD3 and were based

on the Administrative Records for those RODs. The actions

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required by this First Amendment to Order No. 94-12 are based upon

all previous administrative records for the Site and the

administrative records for this First Amendment to Order No. 94-

12.

II. NOTICE TO THE STATE

30. Prior to issuing this First Amendment to Order No. 94-12, EPA

notified the State of California Department of Toxic Substances

Control, that EPA would be issuing this Amendment to Order No. 94-

12.

III. ORDER

31. The following provisions modify requirements contained in

Order 94-12:

HDS Treatment of AMD Flows

32. Starting January 7, 1997, Respondents shall treat, using the

high density sludge treatment process, acid mine drainage from the

Richmond and Lawson Portals and the Old Mine/No. 8 Seep.

33. Respondents shall operate the HDS plant in a manner that

conforms with the Operations and Maintenance Manual attached as

Attachment A and that conforms with the Long-Term Performance

Requirements contained in Table 2-2 of Attachment B.

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34. Respondents shall operate the HDS plant in a manner that

optimizes sludge density and shall use their best efforts to meet

or exceed the sludge densities contained in Table 2-3 of

Attachment B.

35. Respondents shall permit EPA and EPA representatives to

monitor plant operations and plant performance in whatever manner

EPA and its representatives deem appropriate. This paragraph does

not supersede or affect any rights of inspection or other rights

that EPA has under this Order, as amended, or any other order or

any other statutory authority. Upon oral request by EPA or an EPA

representative, Respondents shall provide immediate access to AMD

flow data, and all other analytical data that is currently

available, in hard copy and electronic format. In conducing its

monitoring activities, EPA and its representatives will endeavor

to minimize interference with Respondents' operation and

maintenance of the treatment plant.

EPA Performance Test

36. EPA will conduct one or more 14-day performance tests of the

HDS system. EPA anticipates that the performance test(s) will

occur between January 7, 1997 and June 30, 1997. Respondents

shall cooperate with EPA and EPA representatives in performing

these tests, by among other things, permitting EPA and its

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representatives access to the plant site, plant equipment, process

flows, plant data and plant laboratory equipment. The 14-day

performance test is described in Attachment B. During these 14-

day performance tests, EPA and its representatives will endeavor

to minimize interference with Respondents' operation and

maintenance of the treatment plant.

Sludge Disposal

37. Respondents shall dispose of the treatment sludges in Brick

Flat Pit in a manner consistent with the dry landfill operations

practices concept contained in Attachment D of Unilateral Order

93-01 (the "Dry Landfill Concept"). Brick Flat Pit shall be

managed in accordance with the EPA approved Landfill Management

Report and Plan ("LMRP").

38. Within 90 days of the date of this First Amendment to Order

No. 94-12, Respondents shall submit to EPA a Brick Flat Pit

Baseline Status Report which shall describe the current condition

of Brick Flat Pit and provide an engineering evaluation of the

status of simple mix sludges deposited within the landfill. The

Baseline Status Report shall provide an evaluation of historic

sludge management practices associated with treatment plant

operations, sludge dewatering, excavation, hauling and placement

in BFP. The Brick Flat Pit Baseline Status Report shall contain,

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at a minimum, the following information:

a. An as-built drawing of the Brick Flat Pit Landfill

showing the final as-built topography prior to sludge placement

both in hard copy and electronic file format;

b. The location of all sludge disposed of at the landfill

to date both in hard copy and electronic file format;

c. Computed estimates of the volume of sludge placed in

Brick Flat Pit to date, including hard copy calculations and

electronic file format;

d. A complete listing of all analytical and geotechnical

data that has been produced or obtained to date by the Respondents

pertaining to sludge production at the treatment plant at

Minnesota Flats;

e. A complete listing of computed sludge haulage data

including volume, unit and total costs for sludge excavation and

haulage, repair and O&M of sludge drying beds, repair and O&M of

the haulage roads; and repair and O&M associated with the Brick

Flat Pit landfill operations and facilities;

f. A complete listing of the records and data pertaining to

filtrate contamination of sludge drying bed underdrain systems and

repair records for geotextile protective layers;

g. A complete listing (including detailed acvtivity

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descriptions, engineering analyses and drawings) of any and all

changes to the EPA approved plans and specifications for the

sludge drying beds and Brick Flat Pit landfill facilities that

have been implemented without EPA approval. Examples of such

changes include, but are not limited to, removal of the sludge

drying bed geogrid protective layer, the removal of the protective

drainage rock from the filtrate riser pipes at Brick Flat Pit, and

the constructed dumping location at the west end of Brick Flat

Pit.

h. The current configuration of all drainage and erosion

control features in use;

i. A complete engineering evaluation of the

operability/functionality of the BFP filtrate collection system;

j. A discussion of any areas of concern or non-compliance.

The discussion shall include detailed illustrations of the area of

concern or non-compliance and the plans to correct any

deficiencies.

k. Compaction test reports;

1. Location of all access points including the point

currently being used for sludge dumping into the fill; and

m. Discussion of any changes in landfill management

practices or failures in BFP features or constructed facilities

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and the sludge fill since commencement of placement operations.

39. By November 30th of each year, Respondents shall provide to

EPA, for EPA review and approval, an annual report on landfill

management practices (the Landfill Management Report and Plan)

that addresses landfill management for the 12-month period ending

on October 31 of that year and planned operations for the 12-month

period beginning on November 1 of that year. In the event that a

sludge haul occurs during the month of November, Respondents shall

provide data related to that sludge haul as a supplement to the

annual report. Respondents shall provide such supplement by

December 31 of the year in which the November sludge haul occurs.

40. Within 120 days of the effective date of this First Amendment

to Order No. 94-12 Respondents shall submit to EPA for EPA review

and approval a workplan that specifies the proposed contents of

the annual Landfill Management Report and Plan ("LMRP") and

documents the enginering studies to be performed in support of the

LMRP. The LMRP shall contain sufficient information to enable EPA

to effectively evaluate whether the landfill was properly managed,

consistent with the concept design for a dry landfill, over the

preceding 12 month period, and that the BFP landfill would be

properly managed as a dry landfill over the upcoming 12 month

period.

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41. With respect to operations from the preceding 12-month period

ending on October 31 of that year, the Landfill Management Report

and Plan shall contain at a minimum the following information:

a. An updated as-built drawing of the BFP landfill, with

updated topography;

b. A discussion of the manner in which sludge was

dewatered, excavated, hauled and placed in the BFP landfill,

landfill operations practices, and any problems encountered during

sludge dewatering, excavation, haulage and placement, or landfill

operations;

c. A discussion of areas of non-compliance;

d. A discussion of repairs that were made to sludge

dewatering or BFP landfill facilities, or construction activities

that were undertaken modify sludge dewatering and BFP landfill

facilities;

e. As a minimum, the following flow, analytical and

geotechnical data shall be included in the LMRP:

i. Sludge influent flow rates to sludge drying beds

(to be reported as a daily average);

ii. Filtrate flow rates from sludge drying beds and

Brick Flat Pit (to be reported as a daily average);

iii. Filtrate water quality from sludge drying beds (to

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be reported as a composite daily average) and

Brick Flat Pit (to be reported as a daily average);

iv. Sludge volume, specific gravity, solids contents

of sludge hauled to Brick Flat Pit (to be reported in

a manner consistent with the Operations and Maintenance Plan for

at least six locations from each sludge dewatering bed);

v. Total volume of Sludge in Brick Flat Pit and

stage/elevation curves;

vi. Results of routine analytical testing conducted on

Brick Flat filtrate and seepage discharge. This testing

shall include, as a minimum , flowrate, pH, total and

dissolved cooper, zinc, cadmium, and lead; and total iron and

ferrous iron. Respondents shall conduct this testing at

least every 2-weeks. In conducting this analysis,

Respondents shall comply with the procedures and standards

set forth in Sections 4,5,6,7 and 8 of Attachment B; and

f. Any inconsistencies between the activities or operations

projected in the previous LMRP and the activities or operations

actually undertaken during the projected period.

42. With respect to future operations for the 12-month period

beginning on November 1 of the year, the Landfill Management

Report and Plan shall contain at a minimum the following

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information:

a. Identification of the area of the landfill to be used

for the placement of seasonal sludge production; a description of

sludge placement and landfill operations practices to be

employed;

b. Specifically identify each planned construction activity

to repair or modify sludge dewatering or landfill facilities and

any changes to sludge dewatering or landfill operations

practices; and

c. A discussion of any areas of concern;

d. A complete listing of the analytic and geotechnical

testing and methods that will be completed

i. prior to sludge haulage;

ii. during the sludge haulage; and

iii. On a routine basis.

Equipment Failure

43. In the event of equipment failure at the Site, Respondents

shall follow the following procedures:

a. In the case of equipment failure that causes or

threatens to (1) cause the release of AMD from the treatment

plant that is not fully treated in compliance with Table 2-2 of

Attachment B or (2) require Respondents to operate the plant in

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aerated simple mix mode, Respondents shall:

i. Take all steps necessary to avoid and minimize the

release or threatened release from the treatment plant of AMD

that is not fully treated in compliance with Table 2-2 of the

Attachment B;

ii. Take all steps necessary to cure the problem that

causes or threatens to cause Respondents to operate the plant in

aerated simple mix mode and to cure the equipment failure as soon

as possible; and

iii. Notify EPA within eight hours of discovering the

failure by contacting the RPM by telephone.

b. In the case of any and all other equipment failures,

Respondents shall:

i. Take all steps necessary to repair or replace the

equipment as soon as necessary and

ii. Notify EPA within 48 hours of discovering the

failure by contacting the RPM via telephone.

c. Respondents shall report all equipment failures in the

appropriate monthly report.

44. EPA has equipped the treatment plant with certain essential

and long lead-time spare parts. However, Respondents are solely

responsible for:

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a. Determining which spare parts are necessary or

appropriate to maintain on-site and

b. Maintaining necessary and appropriate spare parts at

the plant site.

Monitoring and Reporting Requirements

45. Respondents shall provide a monthly report to EPA and such

other persons as EPA identifies that describes the monthly

operation of the treatment plant.

46. Respondents shall monitor and report HDS plant performance

and AMD flow in accordance with the requirements set forth in

Section 3 of the Performance Standards and Verification Plan

("PSVP"), attached hereto as Attachment B. Respondents shall

conduct such monitoring and reporting in accordance with the

procedures and standards set forth in Sections 4,5,6,7 and 8 of

Attachment B. Respondents shall submit the information in a

monthly report to EPA and to such other persons as EPA

identifies. i. Respondents shall also include in the monthly

report results of analytical testing conducted on Brick Flat Pit

filtrate and seepage discharges that are called for in the

Landfill Management Report and Plan. Until EPA approves the data

to be included in the Landfill Management Report and Plan

pursuant to paragraph 39, Respondents shall include in the

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monthly report the following analytical data conducted on Brick

Flat Pit filtrate and seepage discharge: flowrate; pH; total and

dissolved copper, zinc, cadmium, and lead; total iron and ferrous

iron. In conducting this analysis, Respondents shall comply with

the procedures and standards set forth in Sections 4,5,6,7 and 8

of Attachment B.

47. Respondents shall also include in the monthly report a

detailed description of equipment failures that occurred during

the preceding month, all steps taken to respond to the failure,

whether a release of untreated AMD or other impact occurred as a

result of the failure, and all steps that were or will be taken

to avoid the risk of such failure in the future. The report

shall also include a detailed description of all maintenance

activities that occurred during the month and a description of

significant activities planned for future months.

48. Respondents shall submit the monthly report required by this

Order, as amended, by the twenty-first (21st) of each month.

Unless otherwise specified by EPA, Respondents shall submit the

report by overnight delivery service.

49. These monitoring and reporting requirements supersede the

monitoring and reporting obligations contained in paragraph 29 of

Order 94-12. Other than the obligations contained in paragraph

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29 of Order 94-12, these new reporting and monitoring

requirements do not superseded or change any other requirement

contained in Order 94-12 or other previous orders issued in

connection with the Site. (i) Within 48 hours of receiving a

request for such information from EPA, Respondents shall provide

to EPA, and to such other persons as EPA identifies, AMD flow

data from the Richmond and Lawson Portals and the Old Mine/No. 8

Seep.

50. Unless otherwise specified by EPA, Respondents shall provide

all data (in the monthly report and otherwise) in hard copy and

electronic format.

51. The effective date for the requirements contained in

paragraphs 44 to 51 is January 7, 1997.

Modification of Operation, Reporting, Monitoring or Performance

Standards.

52. The performance standards for the treatment plant are

technology based. If, as a result of experience gained from plant

operation, Respondents come to believe that the performance

standards or monitoring procedures should be modified, Respondents

may submit a request to EPA to approve a change in the standards

or procedures. The request shall contain sufficient information

to allow EPA to determine the appropriateness of the requested

25

changes. Either at the request of Respondents or on EPA's own

initiative, EPA may modify the performance standards or monitoring

procedures as it deems appropriate. Unless otherwise stated by

EPA, a change in such standard or procedures shall become

effective 30 days after EPA notifies Respondents of the change.

53. Respondents are responsible for ensuring that the Operations

and Maintenance Manual is current and reflects the experience

gained during plant operation. Either at the request of EPA or on

a regular basis as determined by Respondents, Respondents shall

review and propose appropriate revisions to the Operations and

Maintenance Manual for the treatment plant. Respondents shall

submit any proposed changes to EPA for review and approval by EPA.

EPA may at its discretion revise the Operations and Maintenance

Manual or the Performance Standards Verification Plan.

Other

54. Although EPA may, at its discretion, provide technical

assistance to Respondents on HDS plant operation, Respondents are

fully responsible for complying with the requirements of this

Order, as amended.

55. The attachments to this order amendment are hereby

incorporated by reference as if set forth herein in full.

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IV. NOTICE OF INTENT TO COMPLY

56. Not later than fifteen calendar days after this Amendment to

Order No. 94-12 is signed by the Director, Superfund Division,

Respondents shall provide written notice to EPA's Remedial Project

Manager ("RPM") stating whether they will comply with the terms of

this Order, as amended. If Respondents do not unequivocally

commit to perform the work as provided by this Order, as amended,

they shall be deemed to have violated this Order and to have

failed or refused to comply with this Order. Respondent's

written notice shall describe, using facts that exist on or prior

to the effective date of this Order, any "sufficient cause"

defenses asserted by Respondents under sections 106(b) and

107 (c) (3) of CERCLA. The absence of a response by EPA to the

notice required by this paragraph shall not be deemed to be

acceptance of Respondent's assertions.

V. UNITED STATES NOT LIABLE

57. The United States, by issuance of this Order, as amended,

assumes no liability for any injuries or damages to persons or

property resulting from acts or omissions by Respondents, or

its (their) directors, officers, employees, agents,

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representatives, successors, assigns, contractors, or consultants

in carrying out any action or activity pursuant to this Order, as

amended. Neither EPA nor the United States may be deemed to be a

party to any contract entered into by Respondents or its (their)

directors, officers, employees, agents, successors, assigns,

contractors, or consultants in carrying out any action or

activity pursuant to this Order, as amended.

VI. EFFECTIVE DATE AND COMPUTATION OF TIME

58. This Order Amendment shall be effective fifteen (15)

calendar days after the Order Amendment is signed by the

Director, Superfund Division. All times for performance of

ordered activities shall be calculated from this effective date.

VII. OPPORTUNITY TO CONFER

59. Respondents may, within seven (7) calendar days after the

date this Order is signed, request a conference with EPA's

Director, Superfund Division, to discuss this Order. If

requested, the conference shall occur no later than seven (7)

days after the request is made and shall be held at EPA Region 9,

75 Hawthorne Street, San Francisco, CA. The Director may

designate an alternate to meet with Respondents in the event of a

schedule conflict.

60. The purpose and scope of the conference shall be limited to

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issues involving the implementation of the response actions

required by this Order and the extent to which Respondents

intends to comply with this Order. This conference is not an

evidentiary hearing, and does not constitute a proceeding to

challenge this Order. It does not give Respondents a right to

seek review of this Order, or to seek resolution of potential

liability, and no official stenographic record of the conference

will be made. At any conference held pursuant to Respondent's

request, Respondents may appear in person or by an attorney or

other representative.

61. Requests for a conference must be by (1) telefacsimile or

(2) telephone followed by written confirmation mailed that day to

Rick SugarekUnited States Environmental Protection Agency

Region 975 Hawthorne Street

San Francisco, California 94105(415) 744-2226 (ph)(415) 744-2180 (fax)

VIII. EFFECT ON PREVIOUS ORDERS

62. Nothing in this order shall be construed to excuse any non-

compliance with any previous order issued to Respondents,

including Order Nos. 89-18, 90-08 and 91-18, 93-01, 94-12.

63. Except as expressly provided herein, nothing in this order

29

shall be construed as amending any previous order issued to

Respondents.

So Ordered, this 27th day of November, 1996.

BY:Keith A. TakataDirector, Superfund DivisionU.S. Environmental Protection Agency, Region 9