SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, DC 20549
                -------------------------------------------

                                 FORM 10-K

(mark one)
[      X ] Annual Report Pursuant to Section 13 or 15(d) of the Securities
       Exchange Act of 1934 for the fiscal year ended April 4, 1998

[   ]  Transition Report Pursuant to Section 13 or 15(d) of the Securities
       Exchange Act of 1934

                       Commission file number 1-9549

                           THERMO TERRATECH INC.
           (Exact name of Registrant as specified in its charter)

Delaware                                                          04-2925807
(State or other jurisdiction of                             (I.R.S. Employer
incorporation or organization)                           Identification No.)

81 Wyman Street, P.O. Box 9046
Waltham, Massachusetts                                            02254-9046
(Address of principal executive offices)                          (Zip Code)
     Registrant's telephone number, including area code: (781) 622-1000

        Securities registered pursuant to Section 12(b) of the Act:

                                                 Name of each exchange
          Title of each class                     on which registered
      Common Stock, $.10 par value              American Stock Exchange

        Securities registered pursuant to Section 12(g) of the Act:
                                    None

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months and (2) has been subject to the filing requirements for
at least the past 90 days. Yes [X] No [ ]

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of the Registrant's knowledge, in definitive proxy or information
statements incorporated by reference into Part III of this Form 10-K or any
amendment to this Form 10-K. [ ]

The aggregate market value of the voting stock held by nonaffiliates of the
Registrant as of May 29, 1998, was approximately $14,762,000.

As of May 29, 1998, the Registrant had 19,513,824 shares of Common Stock
outstanding.

                    DOCUMENTS INCORPORATED BY REFERENCE

Portions of the Registrant's Fiscal 1998 Annual Report to Shareholders for the
year ended April 4, 1998, are incorporated by reference into Parts I and II.

Portions of the Registrant's definitive Proxy Statement for the Annual Meeting
of Shareholders to be held on September 15, 1998, are incorporated by reference
into Part III.

<PAGE>


                                     PART I


Item 1. Business

(a)  General Development of Business

     Thermo TerraTech Inc. (the Company or the Registrant) provides industrial
outsourcing services and manufacturing support encompassing a broad range of
specializations, including infrastructure engineering, design and construction,
environmental compliance, laboratory testing, and metal treating.

     The Company's majority-owned, publicly held Thermo Remediation Inc.
subsidiary is a national provider of environmental-liability management
services. Through a nationwide network of offices, Thermo Remediation offers
these and related consulting services in five areas: industrial remediation,
nuclear remediation, waste-fluids collection and recycling, soil remediation,
and environmental-management and information- consulting. In fiscal 1998, Thermo
Remediation made several small acquisitions: TriTechnics Corporation, an
environmental engineering and consulting firm, for $1.6 million in cash; RPM
Systems, Inc., an environmental-management, planning, and information technology
company, for $0.6 million in cash and 374,507 shares of Thermo Remediation
common stock, valued at $2.4 million; and Benchmark Environmental Corporation, a
provider of nuclear-remediation and waste-management services to government and
private industry, for $2.9 million in cash and 85,106 shares of Thermo
Remediation common stock, valued at $0.5 million. As of April 4, 1998, the
Company owns 69% of Thermo Remediation's outstanding common stock and holds a
$2.7 million principal amount 3 7/8% subordinated convertible note due 2000
issued by Thermo Remediation, convertible into shares of Thermo Remediation
common stock at a conversion price of $9.83 per share.

     The Company's majority-owned Thermo EuroTech N.V. subsidiary, located in
the Netherlands, specializes in converting "off-spec" and contaminated petroleum
fluids into useable oil products. In February 1998, Thermo EuroTech acquired a
70% controlling interest in Green Sunrise Holdings Ltd., an environmental
services and industrial outsourcing firm based in the Republic of Ireland, for
approximately $4.4 million in cash and a commitment to issue 69,200 shares of
its common stock valued at $0.3 million. As of April 4, 1998, the Company owns
56% of Thermo EuroTech's outstanding common stock.

     In May 1997, the Company purchased a controlling interest in The Randers
Group Incorporated, a publicly traded provider of design, engineering, project
management, and construction services for industrial clients in the
manufacturing, pharmaceutical, and chemical-processing industries. The Company
purchased 7,100,000 shares of Randers common stock from certain members of
Randers' management, and 420,000 shares from Thermo Power Corporation, an
affiliate of the Company, at a price of $0.625 per share, for an aggregate cost
of $4.7 million. Following these transactions and currently, the Company owns
approximately 53.3% of Randers' actual outstanding common stock. In addition,
Thermo Electron Corporation, which owns a majority of the Company's outstanding
common stock, owns approximately 8.9% of actual Randers' outstanding common
stock.
                                     2

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           Subsequently, in September 1997, the Company entered into a
definitive agreement to transfer its wholly owned The Killam Group Inc.
subsidiary to Randers in exchange for newly issued shares of Randers' common
stock. The Killam Group provides comprehensive engineering and outsourcing
services in such areas as water and wastewater treatment, highway and bridge
projects, process engineering, construction management, and inspection and
operational services. Effective April 4, 1998, the agreement was amended to
provide that the price for The Killam Group would be equal to $70.6 million, the
book value of the transferred businesses as of April 4, 1998. The number of new
shares of Randers common stock to be issued to the Company will equal such book
value divided by $0.625, or 113,031,051 shares. Upon such issuance, the Company
and Thermo Electron would own approximately 94.8% and 1.0%, respectively, of
Randers'outstanding common stock. The transfer is subject to approval of the 
transaction by Randers' shareholders and continued listing of Randers' common 
stock on the American Stock Exchange following the transaction. However, 
because the Company currently owns 53.3% of Randers' outstanding common stock, 
approval by Randers'shareholders is assured.

          The Company's Lancaster Laboratories Inc. subsidiary, based in
Lancaster, Pennsylvania, operates analytical laboratories that provide
comprehensive laboratory-based environmental testing, analysis, and related
services to detect and measure organic contaminants in samples of soil, water,
air, industrial wastes, mixed wastes, and biological materials. Lancaster
Laboratories is also a provider of high-quality analytical and consulting
services to the pharmaceutical and food industries.

           The Company performs metallurgical processing services using
thermal-treatment equipment at locations in California, Minnesota, and
Wisconsin. In October 1997, the Company sold substantially all of the assets of
its Holcroft Division, its thermal-processing equipment business, excluding
certain accounts receivable, to Holcroft L.L.C., an affiliate of Madison Capital
Partners, for $10.9 million in cash, two promissory notes for principal amounts
aggregating $2.9 million, and the assumption by Holcroft L.L.C. of certain
liabilities of the Holcroft Division. After recording a post-closing purchase
price adjustment, the Company incurred a nominal loss on the sale. This business
comprised the Company's product revenues and contributed $893,000 and $1,765,000
of operating income in fiscal 1998 and 1997, respectively.

       The Company was incorporated on May 30, 1986, as an indirect, wholly
owned subsidiary of Thermo Electron. As of April 4, 1998, Thermo Electron owned
15,935,435 shares of the common stock of the Company, representing 82% of such
stock outstanding. Thermo Electron develops, manufactures, and markets
analytical and monitoring instruments; biomedical products including
heart-assist devices, respiratory-care equipment, and mammography systems; paper
recycling and papermaking equipment; alternative-energy systems; industrial
process equipment; and other specialized products. Thermo Electron also provides
industrial outsourcing, laboratory, and metallurgical services, and conducts
advanced-technology research and development.
                               3
<PAGE>
     Thermo Electron may repurchase shares of the Company's, Thermo
Remediation's, Randers; or Thermo EuroTech's common stock from time to time in
the open market or in negotiated transactions. During fiscal 1998(1), Thermo
Electron purchased 1,230,777 shares, 8,500 shares, and 349,664 shares of the
Company's, Thermo Remediation's, and Thermo EuroTech's common stock,
respectively, in the open market and negotiated transactions for a total price
of $13,900,000, $62,000, and $1,400,000, respectively.

Forward-looking Statements

     Forward-looking statements, within the meaning of Section 21E of the
Securities Exchange Act of 1934, are made throughout this Annual Report on Form
10-K. For this purpose, any statements contained herein that are not statements
of historical fact may be deemed to be forward-looking statements. Without
limiting the foregoing, the words "believes," "anticipates," "plans," "expects,"
"seeks," "estimates," and similar expressions are intended to identify
forward-looking statements. There are a number of important factors that could
cause the results of the Company to differ materially from those indicated by
such forward-looking statements, including those detailed under the heading
"Forward-looking Statements" in the Registrant's Fiscal 1998 Annual Report to
Shareholders, which statements are incorporated herein by reference.

(b)  Financial Information About Industry Segments

     The Company conducts business in one segment: outsourcing services. The
Company's principal services are environmental-liability management, engineering
and design, and laboratory-based testing. The Company also provides specialized
metal-treating services which, until October 1997, included the design,
manufacture, and installation of advanced custom-engineered thermal-processing
systems.

(c)  Description of Business

     (i) Principal Services and Products

Remediation and Recycling Services

     The Company provides environmental consulting and remediation construction
management to clients in the transportation, refining, chemical, wood-treating,
gas, and electric utility industries across the nation. Through its consulting,
engineering, and on-site services, the Company offers a broad array of remedial
solutions to help clients manage problems associated with environmental
compliance, waste management, and the remediation of industrial sites
contaminated with various wastes and residues. The Company provides particular
expertise in bioremediation, and in managing wastes from manufactured-gas
plants, refineries, and railroad properties.

----------------------
1  References to fiscal 1998, 1997, and 1996 herein are for the fiscal years
   ended April 4, 1998, March 29, 1997, and March 30, 1996, respectively.
                                  4

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     The Company performs the cleanup of hazardous waste sites for government
and industry as a prime construction contractor and completes predesigned
remedial action contracts at sites containing hazardous, toxic, and radioactive
wastes. Under contracts with federal and state governments, and other public-
and private-sector clients, the Company also provides project management and
construction services for the remediation of hazardous and nonhazardous wastes.
Most of this contract work is obtained through a bid process, with the job being
awarded to the lowest qualified bidder.

     The Company provides services to remove radioactive contaminants from soil,
as well as health physics services, radiochemistry laboratory services,
radiation dosimetry services, radiation-instrument calibration and repair
services, and radiation-source production. As part of its radiation and
nuclear/health physics services business, the Company provides site surveys for
radioactive materials and on-site samples, as well as analysis in support of
decontamination programs and dosimetry services to measure personnel exposure.
In addition, using its proprietary segmented-gate system technology, the Company
removes radioactive contaminants from soil. A substantial part of the Company's
health physics services has been performed under the U.S. Department of Energy's
remedial action programs.

     The Company collects, tests, processes, and recycles used motor oil and
other industrial fluids. In addition, the Company collects and recycles oily
water and oil filters. The company has processing facilities in Phoenix and
Tucson, Arizona; Las Vegas, Nevada; Nampa, Idaho; Commerce City, Colorado; and
Portland, Oregon from which it operates a fleet of oil and water collection
trucks to pick up waste oils and oily water. Each facility consists of a series
of tanks set in protective enclosures used to store the fluids before
processing. Processing of oil consists of straining, filtering, and blending.
Once processed, the oil is sold as burner fuel for a variety of industrial uses,
including use in cement and asphalt kilns, industrial furnaces, and as "cutter
stock" to make marine diesel fuel for large, oceangoing vessels. Water is
processed to reclaim all usable oil and remove solid contaminants until the
water meets sewer-discharge standards.

     Thermo EuroTech specializes in processing "off-spec" mixtures of oil that
contain water, ash, and sediment into commercially tradable end products used in
blending. The end products of this process are commercial grade oils that can be
blended to make diesel fuels and marine fuels or be used as a feed material.
Although a large percentage of Thermo EuroTech's oil feedstock has historically
come from the former Soviet Union, Thermo EuroTech no longer receives any oil
from that nation as a result of political and economic changes that make
transportation of waste oil difficult. To overcome this loss of supply, Thermo
EuroTech has taken steps to replace and diversify its feedstock suppliers.
However, no assurance can be given that it will not experience future
disruptions in deliveries. The Company's strategy is to use Thermo EuroTech as a
platform from which to eventually provide a broad range of environmental-
remediation services throughout Western Europe. Thermo EuroTech also provides
in-plant waste management and recycling services through its Ireland-based Green
Sunrise subsidiary, acquired in February 1998.
                                   5
<PAGE>
     The Company designs and operates facilities for the remediation of
nonhazardous soil. The Company's soil-remediation centers are environmentally
secure facilities for receiving, storing, and processing petroleum-contaminated
soils. Each site consists principally of a soil-remediation unit and a
soil-storage area. The Company currently provides soil-remediation services at
facilities in California, Oregon, Washington, South Carolina, Maryland, and New
York.

     The market for remediation of petroleum-contaminated soils, as with many
other waste markets, was created by environmental regulations. The market for
soil-remediation services has been driven largely by state programs to enforce
the Environmental Protection Agency's (EPA's) underground storage tank (UST)
regulations and to fund cleanups. UST compliance requirements and attendant
remediation costs are often beyond the financial capabilities of individuals and
smaller companies. To address this problem, some states established
tax-supported trust funds to assist in the financing of UST compliance and
remediation. Many states have realized that the number of sites requiring
remediation and the costs of compliance are substantially higher than were
originally estimated. As a result, several states have significantly reduced
compliance requirements and altered regulatory approaches and standards in order
to reduce the costs of cleanup. More lenient regulatory standards, reduced
enforcement, and uncertainty with respect to such changes have already resulted
in lower levels of cleanup activity in most states where the Company conducts
business, which has had a material adverse effect on the Company's business.

     During fiscal 1998, 1997, and 1996, the Company derived revenues of $142.4
million, $126.8 million, and $77.0 million, respectively, from
environmental-liability management services.

Consulting and Design Services

     The Company provides comprehensive engineering and outsourcing services in
such areas as water and wastewater treatment, highway and bridge projects,
process engineering, construction management, and operational services. Also,
the Company provides a wide range of comprehensive environmental consulting and
professional engineering services to private- and public-sector clients. These
services include the design and inspection of water supply and wastewater
treatment facilities; investigations of different methods to clean up
hazardous-waste sites; assistance in obtaining government permits;
transportation-related and similar types of infrastructure engineering, survey,
and land-use planning; and support services including mechanical, electrical,
and structural engineering. In addition, the Company provides natural resource
management services, including environmental-impact studies.

     The Company offers engineering, consulting, and design services in
the areas of municipal and industrial water quality management, bridge and
highway construction and reconstruction, and natural resource management.
The Company specializes in the design, planning, and construction
supervision of municipal and privately owned water-treatment plants, waste
treatment plants, and hazardous-wastewater facilities. The
                                6
<PAGE>
Company provides full-service contract operations to plant owners in the public
and private sectors. These services facilitate regulatory compliance; optimize
day-to-day plant operations; reduce costs; provide competent, experienced
personnel; and promote good community relations.

     The Company also provides a broad range of bridge and highway engineering
services.

     The Company's environmental-impact assessments and mitigation and
restoration studies help to determine water quality, promote the safety of
wildlife, and assist clients in meeting environmental permitting and licensing
requirements. The Company also provides aquatic biology expertise and ecological
risk assessment to electric utility plants throughout the country.

     A substantial portion of the Company's engineering and design services
sales are made to existing customers on a repeat basis. Engineering and design
services are often performed as multiyear studies. In addition to federal,
state, and local governments, customers include public utilities, consulting and
construction engineers, waste management companies, oil refineries, mining
companies, chemical manufacturers, architectural and engineering firms, and a
variety of service companies involved with real estate transactions.

     During fiscal 1998, 1997, and 1996, the Company derived revenues of $84.6
million, $74.8 million, and $74.0 million, respectively, from engineering and
design services.

Laboratory-testing Services

     The Company provides comprehensive laboratory-based services for the
environmental, pharmaceutical, and food industries. These laboratories also
provide analysis and related services to detect and measure hazardous wastes and
radioactive materials.

     Analytical laboratory services consist of a comprehensive range of
analytical tests to detect and measure organic contaminants, inorganic
contaminants, and radioactive materials in samples of soil, water, air,
industrial wastes, and biological materials. The Company has established
detailed procedures and strict operating standards to ensure consistent
performance and to allow it to participate in the EPA's Contract Laboratory
Program. The Company's environmental laboratory business has been negatively
affected by reduced federal spending on environmental testing.

     During fiscal 1998, 1997, and 1996, the Company derived revenues of $37.5
million, $35.4 million, and $35.5 million, respectively, from laboratory-testing
services. Revenues from laboratory-testing services exclude radiochemistry
laboratory service revenues included in environmental-liability management
services.
                                   7

<PAGE>


Metal-treating Services and Process Systems

     The Company performs metallurgical processing services using
thermal-treatment equipment at locations in California, Minnesota, and
Wisconsin. Through its Holcroft Division, which was sold in October 1997, the
Company designed, manufactured, and installed computer-controlled,
custom-engineered, thermal-processing systems used to treat primary metals and
metal parts. During fiscal 1998, 1997, and 1996, the Company derived revenues of
$36.6 million, $44.3 million, and $35.8 million, respectively, from
metal-treating services and process systems.

     (ii) New Products

     The Company has made no commitments to new products that would require the
investment of a material amount of the Company's assets.

     (iii) Raw Materials

     Prior to fiscal 1996, a large percentage of Thermo EuroTech's oil feedstock
came from the former Soviet Union. Thermo EuroTech no longer receives any oil
from that nation as a result of political and economic changes that make
transportation of waste oil difficult. To overcome this loss of supply, Thermo
EuroTech has taken steps to replace and diversify its feedstock suppliers.
However, no assurance can be given that it will not experience future
disruptions in deliveries.

     (iv) Patents, Licenses, and Trademarks

     The Company currently owns or has rights under licenses to a number of U.S.
patents. Although the Company believes that patent protection provides it with
competitive advantages with respect to certain portions of its business and will
continue to seek patent protection when appropriate, the Company also believes
that its business depends primarily upon trade secrets and the technical and
marketing expertise of its personnel.

     (v) Seasonal Influences

     A majority of the Company's businesses experience seasonal fluctuations. A
majority of the Company's soil-remediation sites, as well as the Company's
fluids-recycling sites, experience declines in severe weather conditions. Site
remediation work and certain environmental testing services may decline in
winter months as a result of severe weather conditions. In Europe, Thermo
EuroTech may experience a decline in the feedstock delivered to its facilities
during winter months, due to frozen waterways.

     (vi) Working Capital Requirements

     In general, there are no special inventory requirements or credit terms
extended to customers that would have a material adverse effect on the Company's
working capital.
                                       8

<PAGE>


     (vii) Dependency on a Single Customer

     See Government Contracts.

     (viii) Backlog

     The Company's backlog of firm orders was $111.8 million and $108.7 million
as of April 4, 1998, and March 29, 1997, respectively. These amounts include the
backlog of all of the Company's subsidiaries, with the exception of
soil-recycling and fluids-recycling, which are provided on a current basis
pursuant to purchase orders. Included in the Company's backlog at fiscal
year-end 1998 and 1997 is the incomplete portion of contracts that are accounted
for using the percentage-of-completion method. The Company believes that
substantially all of the backlog at April 4, 1998, will be completed during the
next 12 months. Certain of these orders are subject to cancellation by the
customer upon payment of a cancellation charge and all government contracts are
subject to termination at any time by the government without penalty.

     (ix) Government Contracts

     Approximately 4%, 13%, and 10% of the Company's revenues in fiscal 1998,
1997, and 1996, respectively, were derived from contracts or subcontracts with
the federal government that are subject to renegotiation of profits or
termination. The Company does not have any knowledge of threatened or pending
renegotiation or termination of any material contract or subcontract.

     (x) Competition

     Many of the Company's businesses are engaged in highly competitive,
regional markets, with competition coming from numerous small firms offering
limited services, as well as much larger firms that offer an array of services.

Environmental-liability Management Services

     In the market for industrial-remediation services, the Company competes
with numerous regional or local companies as well as a number of national
remediation contractors. The Company competes primarily based on price, as the
vast majority of the contracts it seeks are awarded on the basis of scope,
effectiveness, and cost. Other competitive factors for the Company's
industrial-remediation businesses include: reputation; experience; breadth and
quality of services offered; and technical, managerial, and business
proficiency.

     The type of nuclear-remediation services offered by the Company are also
offered by many large national companies. The Company competes primarily on the
basis of its proprietary technology and price.

     The Company operates the largest fleet of waste-fluids collection vehicles
in Arizona and Nevada. The Company competes with numerous smaller and several
larger collection companies in its current market primarily on the basis of
quality of service and price.
                                  9
<PAGE>
     Competition in the soil-remediation business is intense. The Company's
principal competitors are landfills, including major landfill companies. The
Company also currently competes with companies offering a wide range of disposal
options, including other fixed-site, thermal-treatment facilities, operators of
mobile thermal-treatment facilities, bioremediation and vapor-extraction
facilities, and, in certain states, with asphalt plants and brick kilns that use
the contaminated soil in their production processes. Competition in the
soil-remediation market has always been highly localized, consisting mostly of
single-site or single-unit operators. Competitive conditions limit the prices
charged by the Company in each local market for soil-remediation services.
Pricing is therefore a major competitive factor for the Company. The Company
believes competition and pricing pressure will remain intense for the
foreseeable future.

     Fewer than 20 companies offer environmental management and information
systems of the type provided by the Company. While some of these companies
possess similar resources as the Company, many are large, national consulting
firms that devote a relatively small percentage of their resources to this area.
The Company competes for business, both regionally and nationally, primarily
based on reputation and the quality of its services and, to a lesser extent, on
price. Less than 10% of the Company's work in this area is obtained through a
bidding process.

     Thermo EuroTech faces competition for oil from other oil processors and
blenders and from a company with a similar distillation technology in Italy. The
market for blending oils is very large and oils such as Thermo EuroTech's end
products represent a very small percentage of the total market. Thermo EuroTech
competes primarily based on price.

Engineering and Design Services

     The Company's engineering and design businesses are engaged in highly
competitive markets in all of its service areas. These markets tend to be
regional. In its geographic service area, competition consists of small, one- to
three-person firms offering a limited scope of services, as well as much larger
firms that may be regional, national, or international in the scope of services
they offer. The principal competitive factors for the Company are: reputation;
experience; price; breadth and quality of services offered; and technical,
managerial, and business proficiency.

Laboratory-testing Services

     Hundreds of independent analytical testing laboratories and consulting
firms compete for business nationwide. Many of these firms use equipment and
processes similar to those of the Company. Competition is based not only on
price, but also on reputation for accuracy, quality, and the ability to respond
rapidly to customer requirements. In addition, many industrial companies have
their own in-house analytical testing capabilities. The Company believes that
its competitive strength lies in the quality of its services.
                                     10

<PAGE>


Metal-treating Services

     The market for metal-treating services is typically regional and
competitive. All regions in which the Company has facilities contain numerous
competitors. In addition, in-house heat-treating facilities provide a major
source of competition. The Company competes in this segment on the basis of
services provided, turnaround time, and price.

     (xi) Environmental Protection Regulations

     The Company believes that compliance by the Company with federal, state,
and local environmental protection regulations will not have a material adverse
effect on its capital expenditures, earnings, or competitive position.

     (xii) Number of Employees

     At April 4, 1998, the Company employed 2,736 persons.

(d)  Financial Information About Exports by Domestic Operations and About
     Foreign Operations

     The Company's exports by domestic operations and foreign operations are
currently insignificant.

(e)  Executive Officers of the Registrant

                                 Present Title (Fiscal Year First Became
    Name                   Age   Executive Officer)

    Dr. John P. Appleton    63   President and Chief Executive Officer
                                   (1993)
    John N. Hatsopoulos     63   Chief Financial Officer and Senior Vice
                                   President (1988)
    Emil C. Herkert         60   Vice President (1996)
    Jeffrey L. Powell       39   Vice President (1994)
    Paul F. Kelleher        55   Chief Accounting Officer (1986)

     Each executive officer serves until his successor is chosen or appointed by
the Board of Directors and qualified or until earlier resignation, death, or
removal. All executive officers, except Mr. Herkert and Mr. Powell, have held
comparable positions for at least five years, either with the Company or with
its parent company, Thermo Electron. Mr. Herkert has served as President of
Killam Associates, a subsidiary of Randers, since 1977. Mr. Powell served as
President of Thermo Remediation since its inception in 1993, and as its Chief
Executive Officer from May 1997 until April 1998, when he was named Senior Vice
President. Messrs. Hatsopoulos and Kelleher are full-time employees of Thermo
Electron, but devote such time to the affairs of the Company as the Company's
needs reasonably require.
                                    11

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Item 2. Properties

     The location and general character of the Company's principal properties as
of April 4, 1998, are as follows:

     The Company owns approximately 490,000 square feet of office, engineering,
laboratory, and production space, principally in Pennsylvania, Minnesota, New
Jersey, Ireland, Idaho, Wisconsin, and California, and leases approximately
730,000 square feet of office, engineering, laboratory, and production space
pursuant to leases expiring in fiscal 1999 through 2023, principally in
California, Pennsylvania, New Mexico, New York, Massachusetts, New Jersey, New
Hampshire, and Florida.

     The Company also owns approximately 70 acres in Maryland, California, and
Oregon, from which it provides soil-remediation services. The Company occupies
approximately 19 acres principally in New York, Washington, California, and
South Carolina pursuant to leases expiring in fiscal 1999 through 2006, from
which it provides soil-remediation services.

     The Company leases approximately six acres on one site in Arizona and one
site in Nevada pursuant to leases expiring in fiscal 1999, consisting of office
space, fluids recycling and maintenance facilities, and sites for fluids storage
tanks.

     The Company occupies approximately 15 acres in Delfzijl, Holland, pursuant
to a lease expiring in 2059, consisting of office space, distillation
facilities, and oil storage tanks.

     The Company believes that these facilities are in good condition and are
adequate for its present operations and that other suitable space is readily
available if any of such leases are not extended. With respect to leases
expiring in the near future, in the event the Company does not renew such
leases, the Company believes suitable alternate space is available for lease on
acceptable terms.

Item 3. Legal Proceedings

     Not applicable.

Item 4. Submission of Matters to a Vote of Security Holders

     Not applicable.
                                       12

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                                  PART II


Item 5. Market for Registrant's Common Equity and Related Stockholder
         Matters

     Information concerning the market and market price for the Registrant's
Common Stock, $.10 par value, and dividend policy are included under the
sections labeled "Common Stock Market Information" and "Dividend Policy" in the
Registrant's Fiscal 1998 Annual Report to Shareholders and is incorporated
herein by reference.

Item 6. Selected Financial Data

     The information required under this item is included under the sections
labeled "Selected Financial Information" and "Dividend Policy" in the
Registrant's Fiscal 1998 Annual Report to Shareholders and is incorporated
herein by reference.

Item 7. Management's Discussion and Analysis of Financial Condition and
        Results of Operations

     The information required under this item is included under the heading
"Management's Discussion and Analysis of Financial Condition and Results of
Operations" in the Registrant's Fiscal 1998 Annual Report to Shareholders and is
incorporated herein by reference.

Item 8. Financial Statements and Supplementary Data

     The Registrant's Consolidated Financial Statements as of April 4, 1998, are
included in the Registrant's Fiscal 1998 Annual Report to Shareholders and are
incorporated herein by reference.

Item 9. Changes in and Disagreements with Accountants on Accounting and
         Financial Disclosure

     Not applicable.
                                      13

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                                  PART III


Item 10. Directors and Executive Officers of the Registrant

     The information concerning Directors required under this item is
incorporated herein by reference from the material contained under the
caption "Election of Directors" in the Registrant's definitive proxy
statement to be filed with the Securities and Exchange Commission pursuant
to Regulation 14A, not later than 120 days after the close of the fiscal
year. The information concerning delinquent filers pursuant to Item 405 of
Regulation S-K is incorporated herein by reference from the material
contained under the heading "Section 16(a) Beneficial Ownership Reporting
Compliance" under the caption "Stock Ownership" in the Registrant's
definitive proxy statement to be filed with the Securities and Exchange
Commission pursuant to Regulation 14A, not later than 120 days after the
close of the fiscal year.

Item 11. Executive Compensation

    The information required under this item is incorporated herein by
reference from the material contained under the caption "Executive
Compensation" in the Registrant's definitive proxy statement to be filed with
the Securities and Exchange Commission pursuant to Regulation 14A,
not later than 120 days after the close of the fiscal year.

Item 12. Security Ownership of Certain Beneficial Owners and Management

    The information required under this item is incorporated herein by
reference from the material contained under the caption "Stock Ownership"
in the Registrant's definitive proxy statement to be filed with the
Securities and Exchange Commission pursuant to Regulation 14A, not later
than 120 days after the close of the fiscal year.

Item 13. Certain Relationships and Related Transactions

     The information required under this item is incorporated herein by
reference from the material contained under the caption "Relationship with
Affiliates" in the Registrant's definitive proxy statement to be filed with the
Securities and Exchange Commission pursuant to Regulation 14A, not later than
120 days after the close of the fiscal year.
                                     14

<PAGE>


                                  PART IV


Item 14.  Exhibits, Financial Statement Schedules, and Reports on Form 8-K

   (a,d)  Financial Statements and Schedules

          (1) The consolidated financial statements set forth in the list below
              are filed as part of this Report.

          (2) The consolidated financial statement schedule set forth in the
              list below is filed as part of this Report.

          (3) Exhibits filed herewith or incorporated herein by reference are
              set forth in Item 14(c) below.

          List of Financial Statements and Schedules Referenced in this
          Item 14

          Information incorporated by reference from Exhibit 13 filed herewith:

              Consolidated Statement of Operations
              Consolidated Balance Sheet
              Consolidated Statement of Cash Flows
              Consolidated Statement of Shareholders' Investment
              Notes to Consolidated Financial Statements
              Report of Independent Public Accountants

          Financial Schedule filed herewith:

              Schedule II: Valuation and Qualifying Accounts

          All other schedules are omitted because they are not applicable or not
          required, or because the required information is shown either in the
          financial statements or the notes thereto.

     (b)  Reports on Form 8-K

           None.

     (c)  Exhibits

          See Exhibit Index on the page immediately preceding exhibits.
                                      15

<PAGE>


                                 SIGNATURES


     Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the Registrant has duly caused this report to be signed by
the undersigned, thereunto duly authorized.

Date: June 29, 1998                    THERMO TERRATECH INC.



                                       By: John P. Appleton
                                           John P. Appleton
                                           President and
                                             Chief Executive Officer

     Pursuant to the requirements of the Securities Exchange Act of 1934, this
report has been signed below by the following persons on behalf of the
Registrant and in the capacities indicated, as of June 29, 1998.

Signature                              Title



By: John P. Appleton                   President, Chief Executive Officer,
    John P. Appleton                     and Director

By: John N. Hatsopoulos                Chief Financial Officer, Senior
    John N. Hatsopoulos                  Vice President, and Director

By: Paul F. Kelleher                   Chief Accounting Officer
    Paul F. Kelleher

By: Brian D. Holt                      Director
    Brian D. Holt

By: Donald E. Noble                    Director
    Donald E. Noble

By: William A. Rainville               Director
    William A. Rainville

By: Polyvios C. Vintiadis              Chairman of the Board and Director
    Polyvios C. Vintiadis
                                     16

<PAGE>


                  Report of Independent Public Accountants

To the Shareholders and Board of Directors of Thermo TerraTech Inc.:

     We have audited, in accordance with generally accepted auditing standards,
the consolidated financial statements included in Thermo TerraTech Inc.'s Annual
Report to Shareholders incorporated by reference in this Form 10-K, and have
issued our report thereon dated May 12, 1998. Our audits were made for the
purpose of forming an opinion on those statements taken as a whole. The schedule
listed in Item 14 on page 15 is the responsibility of the Company's management
and is presented for purposes of complying with the Securities and Exchange
Commission's rules and is not part of the basic consolidated financial
statements. This schedule has been subjected to the auditing procedures applied
in the audits of the basic consolidated financial statements and, in our
opinion, fairly states in all material respects the consolidated financial data
required to be set forth therein in relation to the basic consolidated financial
statements taken as a whole.



                               Arthur Andersen LLP



Boston, Massachusetts
May 12, 1998
                                   17

<PAGE>


SCHEDULE II

                           THERMO TERRATECH INC.


                     VALUATION AND QUALIFYING ACCOUNTS
                               (In thousands)


                     Balance  Provision
                          at    Charged             Accounts           Balance
                   Beginning         to   Accounts  Written-            at End
Description          of Year    Expense  Recovered       off  Other(a) of Year
------------------------------------------------------------------------------
Allowance for
  Doubtful Accounts

Year Ended
  April 4, 1998     $ 3,838     $ 1,141   $      -  $  (773)  $   244  $4,450

Year Ended
  March 29, 1997    $ 2,861     $   625   $     49  $  (516)  $   819  $3,838

Year Ended
  March 30, 1996    $ 3,572     $    85   $     84  $(1,628)  $   748  $2,861

(a)  Includes allowances of businesses acquired during the year as described in
     Note 3 to Consolidated Financial Statements in the Registrant's Fiscal 1998
     Annual Report to Shareholders and the effect of foreign currency
     translation.
                                         18


<PAGE>


                               EXHIBIT INDEX

Exhibit
Number     Description of Exhibit

  2.1      Purchase and Sale Agreement executed October 6, 1997, by and among
           Remediation Technologies, Inc., RETEC Thermal, Inc., TETRA Thermal,
           Inc., and TETRA Technologies, Inc. (filed as Exhibit 2.1 to Thermo
           Remediation Inc.'s Current Report on Form 8-K dated October 6, 1997
           [File No. 1-12636] and incorporated herein by reference).

  2.2      Assignment and Assumption Agreement executed October 6, 1997, by and
           among Remediation Technologies, Inc., RETEC Thermal, Inc., TETRA
           Thermal, Inc., and TETRA Technologies, Inc. (filed as Exhibit 2.2 to
           Thermo Remediation Inc.'s Current Report on Form 8-K dated October 6,
           1997 [File No. 1-12636] and incorporated herein by reference).

  2.3      Asset Purchase Agreement dated as of October 10, 1997, between the
           Registrant and Holcroft L.L.C. (filed as Exhibit 2.1 to the
           Registrant's Current Report on Form 8-K dated October 6, 1997, and
           incorporated herein by reference).

  2.4      $2,218,000.00 Principal Promissory Note issued by Holcroft L.L.C. to
           the Registrant (filed as Exhibit 2.2 to the Registrant's Current
           Report on Form 8-K dated October 6, 1997, and incorporated herein by
           reference).

  2.5      $663,117.82 Principal Promissory Note issued by Holcroft L.L.C. to
           the Registrant (filed as Exhibit 2.3 to the Registrant's Current
           Report on Form 8-K dated October 6, 1997, and incorporated herein by
           reference).

  2.6      Subordination Agreement dated as of October 10, 1997, between the
           Registrant and Comerica Bank (filed as Exhibit 2.4 to the
           Registrant's Current Report on Form 8-K dated October 6, 1997, and
           incorporated herein by reference).

  2.7      Stock Purchase and Sale Agreement dated May 12, 1997, by and between
           the Registrant and Thomas R. Eurich, Michael J. Krivitzky, Thomas J.
           McEnhill, and Bruce M. Bourdon (filed as Exhibit (iv) to Amendment
           No. 3 to Schedule 13D filed by Thermo Electron Corporation and the
           Registrant on May 13, 1997, and incorporated herein by reference).

  2.8      Amendment No. 1 dated September 19, 1997, to Stock Purchase and Sale
           Agreement dated May 12, 1997, by and between the Registrant and
           Thomas R. Eurich, Michael J. Krivitzky, Thomas J. McEnhill, and Bruce
           M. Bourdon (filed as Exhibit 2.5 to The Randers Group Incorporated's
           Annual Report on Form 10-K for the fiscal year ended April 4, 1998
           [File No. 0-18095] and incorporated herein by reference).
                                       19

<PAGE>


Exhibit
Number     Description of Exhibit

  2.9      Letter of Intent dated May 12, 1997, by and between the Registrant
           and The Randers Group Incorporated (filed as Exhibit (v) to Amendment
           No. 3 to Schedule 13D filed by Thermo Electron Corporation and the
           Registrant on May 13, 1997, and incorporated herein by reference).

  2.10     Stock Purchase Agreement entered on September 19, 1997, by and
           between the Registrant and The Randers Group Incorporated (filed as
           Exhibit (vii) to Amendment No. 4 to Schedule 13D filed by Thermo
           Electron Corporation and the Registrant on October 1, 1997, and
           incorporated herein by reference).

  2.11     Amendment No. 1 dated as of April 4, 1998, to Stock Purchase
           Agreement entered on September 19, 1997, by and between the
           Registrant and The Randers Group Incorporated (filed as Exhibit 2.8
           to The Randers Group Incorporated's Annual Report on Form 10-K for
           the fiscal year ended April 4, 1998 [File No. 0-18095] and
           incorporated herein by reference).

  2.12     Agreement by and among the Registrant, The Randers Group
           Incorporated, Thomas R. Eurich, Michael J. Krivitzky, Thomas J.
           McEnhill, Bruce M. Bourdon, and David A. Wiegerink (filed as Exhibit
           10 to The Randers Group Incorporated's Current Report on Form 8-K
           dated October 3, 1997 [File No. 0-18095] and incorporated herein by
           reference).

  3.1      Restated Certificate of Incorporation, as amended (filed
           as Exhibit 99 to the Registrant's Registration Statement
           on Form S-2 [Reg. No. 333-02269] and incorporated herein
           by reference).

  3.2      Bylaws of the Registrant (filed as Exhibit 3(b) to the Registrant's
           Annual Report on Form 10-K for the fiscal year ended April 2, 1988
           [File No. 1-9549] and incorporated herein by reference).

  4.1      Fiscal Agency Agreement dated as of May 2, 1996, among the
           Registrant, Thermo Electron Corporation, and Chemical Bank, as Fiscal
           Agent (filed as Exhibit 4.2 to the Registrant's Annual Report on Form
           10-K for the fiscal year ended March 30, 1996 [File No. 1-9549] and
           incorporated herein by reference).


                                       20

<PAGE>


Exhibit
Number     Description of Exhibit

  4.2      Fiscal Agency Agreement dated as of May 5, 1995, among Thermo
           Remediation Inc., Thermo Electron Corporation, and Chemical Bank, as
           fiscal agent (filed as Exhibit 4.1 to Thermo Remediation Inc.'s
           Annual Report on Form 10-K for the fiscal year ended April 4, 1998
           [File No. 1-12636] and incorporated herein by reference).

           The Registrant hereby agrees, pursuant to Item 601(b)(4)(iii) (A) of
           Regulation S-K, to furnish to the Commission, upon request, a copy of
           each other instrument with respect to other long-term debt of the
           Company or its subsidiaries.

 10.1      Thermo Electron Corporate Charter as amended and restated effective
           January 3, 1993 (filed as Exhibit 10(a) to the Registrant's Annual
           Report on Form 10-K for the fiscal year ended April 3, 1993 [File No.
           1-9549] and incorporated herein by reference).

 10.2      Amended and Restated Corporate Services Agreement dated January 3,
           1993, between Thermo Electron Corporation and the Registrant (filed
           as Exhibit 10(b) to the Registrant's Annual Report on Form 10-K for
           the fiscal year ended April 3, 1993 [File No. 1-9549] and
           incorporated herein by reference).

 10.3      Agreement of Lease dated December 31, 1985, between
           Claridge Properties Ltd. and Thermo Electron Corporation
           (filed as Exhibit 10(c) to the Registrant's Registration
           Statement on Form S-1 [Reg. No. 33-6763] and incorporated
           herein by reference).

 10.4      Assignment of Lease dated December 31, 1985, between Thermo
           Electron Corporation and TMO, Inc. (filed as Exhibit 10(d) to
           the Registrant's Registration Statement on Form S-1 [Reg. No.
           33-6763] and incorporated herein by reference).

 10.5      Sublease dated March 30, 1986, between TMO, Inc. and
           Holcroft/Loftus, Inc. (filed as Exhibit 10(e) to the
           Registrant's Registration Statement on Form S-1 [Reg. No.
           33-6763] and incorporated herein by reference).

 10.6      Lease Amending Agreement dated January 1, 1995, between
           Claridge Properties Ltd., Thermo Electron Corporation,
           and TMO, Inc. (filed as Exhibit 10.6 to the Registrant's
           Annual Report on Form 10-K [File No. 1-9549] and
           incorporated by reference).
                                      21

<PAGE>


Exhibit
Number     Description of Exhibit

 10.7      Second Amendment to Sublease dated as of October 10, 1997, between
           the Registrant and TMO, Inc. (filed as Exhibit 2.5 to the
           Registrant's Current Report on Form 8-K dated October 6, 1997, and
           incorporated herein by reference).

 10.8      Sublease dated as of October 10, 1997, between the Registrant and
           Holcroft L.L.C. (filed as Exhibit 2.6 to the Registrant's Current
           Report on Form 8-K dated October 6, 1997 and incorporated herein by
           reference).

 10.9      Exclusive License and Marketing Agreement dated March 22, 1990, among
           TPS Technologies Inc., Holcroft Inc., and Thermo Soil Recyclers Inc.
           (filed as Exhibit 10(q) to the Registrant's Annual Report on Form
           10-K for the fiscal year ended March 31, 1990 [File No. 1-9549] and
           incorporated herein by reference).

 10.10     Form of Indemnification Agreement with Directors and Officers (filed
           as Exhibit 10(k) to the Registrant's Annual Report on Form 10-K for
           the fiscal year ended March 30, 1991 [File No. 1-9549] and
           incorporated herein by reference).

 10.11     Development Agreement dated September 15, 1991, between Thermo
           Electron Corporation and the Registrant (filed as Exhibit 10(l) to
           the Registrant's Quarterly Report on Form 10-Q for the fiscal quarter
           ended September 28, 1991 [File No. 1-9549] and incorporated herein by
           reference).

 10.12     Amended and Restated Development Agreement dated January 2, 1992,
           between Thermo Electron Corporation and the Registrant (filed as
           Exhibit 10(m) to the Registrant's Annual Report on Form 10-K for the
           fiscal year ended March 28, 1992 [File No. 1-9549] and incorporated
           herein by reference).

 10.13     Asset Transfer Agreement dated as of October 1, 1993, among the
           Registrant, TPS Technologies Inc., and Thermo Remediation Inc.
           (filed as Exhibit 2.3 to Thermo Remediation's Registration
           Statement on Form S-1 [Reg. No. 33-70544] and incorporated
           herein by reference).

 10.14     Exclusive License Agreement dated as of October 1, 1993, among
           the Registrant, TPS Technologies Inc., and Thermo Remediation
           Inc. (filed as Exhibit 2.4 to Thermo Remediation's Registration
           Statement on Form S-1 [Reg. No. 33-70544] and incorporated
           herein by reference).

                                       22

<PAGE>


Exhibit
Number     Description of Exhibit

 10.15     Non-Competition and Non-Disclosure Agreement dated as of
           October 1, 1993, among the Registrant, TPS Technologies
           Inc. and Thermo Remediation Inc. (filed as Exhibit 2.5 to
           Thermo Remediation's Registration Statement on Form S-1
           [Reg. No. 33-70544] and incorporated herein by reference).

 10.16     Tax Allocation Agreement dated as of June 1, 1992,
           between the Registrant and Thermo Remediation Inc. (filed
           as Exhibit 10.3 to Thermo Remediation's Registration
           Statement on Form S-1 [Reg. No. 33-70544] and
           incorporated herein by reference).

 10.17     Agreement of Partnership dated May 16, 1994, among Terra
           Tech Labs Inc. (a wholly owned subsidiary of the
           Registrant) and Eberline Analytical Corporation, Skinner
           & Sherman, Inc., TMA/NORCAL Inc., Normandeau Associates
           Inc., Bettigole Andrews & Clark Inc., Fellows, Read &
           Associates Inc., and Thermo Consulting Engineers Inc.
           (each a wholly owned subsidiary of Thermo Instrument
           Systems Inc.; filed as Exhibit 1 to the Registrant's
           Current Report on Form 8-K relating to the events
           occurring on May 16, 1994 [File No. 1-9549] and
           incorporated herein by reference).

 10.18     Promissory Note dated May 16, 1994, issued by the Registrant to
           Thermo Electron Corporation (filed as Exhibit 2 to the Registrant's
           Current Report on Form 8-K relating to the events occurring on May
           16, 1994 [File No. 1-9549] and incorporated herein by reference).

 10.19     Agreement of Dissolution of Partnership dated May 9,
           1995, among Thermo Terra Tech (the Partnership), Terra
           Tech Labs, Inc. (a wholly owned subsidiary of the
           Registrant) and Eberline Analytical Corporation, Skinner
           & Sherman, Inc., TMA/NORCAL Inc., Normandeau Associates
           Inc., Bettigole Andrews & Clark Inc., Fellows, Read &
           Associates Inc., and Thermo Consulting Engineers Inc.
           (each a wholly owned subsidiary of Thermo Instrument
           Systems Inc.; filed as Exhibit 2.1 to the Registrant's
           Current Report on Form 8-K relating to the events
           occurring on May 9, 1995 [File No. 1-9549] and
           incorporated herein by reference).

 10.20     Stock Purchase Agreement dated May 9, 1995, between the Registrant
           and Thermo Instrument Systems Inc. (filed as Exhibit 2.2 to the
           Registrant's Current Report on Form 8-K relating to the events
           occurring on May 9, 1995 [File No. 1-9549] and incorporated herein by
           reference).

                                     23

<PAGE>


Exhibit
Number     Description of Exhibit

 10.21     Note dated May 17, 1995, from the Registrant to Thermo Electron
           Corporation (filed as Exhibit 2.3 to the Registrant's Current Report
           on Form 8-K relating to the events occurring on May 9, 1995 [File No.
           1-9549] and incorporated herein by reference).

 10.22     Stock Purchase and Note Issuance Agreement dated as of
           November 22, 1993, between the Registrant and Thermo
           Remediation Inc. (filed as Exhibit 10.11 to Thermo
           Remediation's Registration Statement on Form S-1 [Reg.
           No. 33-70544] and incorporated herein by reference).

 10.23     $2,650,000 principal amount Subordinated Convertible Note
           dated as of November  22,  1993, made by Thermo
           Remediation Inc., issued to the Registrant (filed as
           Exhibit 10.12 to Thermo Remediation's Registration
           Statement on Form S-1 [Reg. No. 33-70544] and
           incorporated herein by reference).

 10.24     Stock Purchase and Sale Agreement made and entered into
           on February 6, 1995, to be effective as of January 29,
           1995, by and between Nord Est S.A., the Registrant, and
           Emil C. Herkert, Kenneth L. Zippler, Franklin O.
           Williamson, Jr., Fletcher N. Platt, Jr., Eugene J.
           Destefano, Meint Olthof, and Stanley P. Kaltnecker, Jr.
           (filed as Exhibit 1 to the Registrant's Current Report on
           Form 8-K relating to the events occurring on February 6,
           1995 [File No. 1-9549] and incorporated herein by
           reference).

 10.25     Agreement and Plan of Merger dated as of June 28, 1995,
           by and among the Registrant, Eberline Acquisition Inc.,
           Thermo Remediation Inc., and Eberline Holdings Inc.
           (filed as Appendix B to Thermo Remediation's Proxy
           Statement for the Annual Meeting held on December 13,
           1995 [File No. 1-12636] and incorporated herein by
           reference).

 10.26     $28,000,000 Secured Promissory Note dated as of January 29, 1995,
           issued by the Registrant to Nord Est S.A. (filed as Exhibit 2 to the
           Registrant's Current Report on Form 8-K relating to the events
           occurring on February 6, 1995 [File No. 1-9549] and incorporated
           herein by reference).

 10.27     $38,000,000 Promissory Note dated as of February 21, 1995, issued by
           the Registrant to Thermo Electron Corporation (filed as Exhibit 3 to
           the Registrant's Current Report on Form 8-K relating to the events
           occurring on February 6, 1995 [File No. 1-9549] and incorporated
           herein by reference).
                                   24

<PAGE>


Exhibit
Number     Description of Exhibit

 10.28     Asset Purchase Agreement by and among Thermo Analytical
           Inc. (as Buyer); Lancaster Laboratories, Inc. and
           Clewmark Holdings (as Sellers); and Earl H. Hess, Anita
           F. Hess, Kenneth E. Hess, J. Wilson Hershey, and Carol D.
           Hess (as the principal owners of Sellers) (filed as
           Exhibit 1 to the Registrant's Current Report on Form 8-K
           relating to the events occurring on May 10, 1995 [File
           No. 1-9549] and incorporated herein by reference).

 10.29     Agreement and Plan of Merger dated as of the first day of
           December 1995, by and among Thermo Remediation Inc., TRI
           Acquisition Inc., and Remediation Technologies, Inc.
           (filed as Exhibit 2(a) to the Registrant's Current Report
           on Form 8-K relating to the events occurring on December
           8, 1995 [File No. 1-9549] and incorporated herein by
           reference).

 10.30     Purchase and Sale Agreement dated as of December 20,
           1994, by and among TPS Technologies Inc., TPST Soil
           Recyclers of Maryland Inc., Rafich Corporation, Harry
           Ratrie, John C. Cyphers, and J. Thomas Hood (filed as
           Exhibit 1 to Thermo Remediation's Current Report on Form
           8-K for the events occurring on December 21, 1994 [File
           No. 1-12636] and incorporated herein by reference).

 10.31     Stock Purchase Agreement entered into on March 29, 1995,
           by and among Stalt Holding, B.V., Beheersmaatschappij J.
           Amerika N.V., A.J. Van Es, J.B. Van Es and D.A. Slager,
           and the Registrant (filed as Exhibit 1 to the
           Registrant's Current Report on Form 8-K relating to the
           events occurring on March 29, 1995 [File No. 1-9549] and
           incorporated herein by reference).

 10.32     Master Repurchase Agreement dated January 1, 1994, between the
           Registrant and Thermo Electron Corporation (filed as Exhibit 10.21 to
           the Registrant's Annual Report on Form 10-K for the fiscal year ended
           April 2, 1994 [File No. 1-9549] and incorporated herein by
           reference).

 10.33     Amended and Restated Master Guarantee Reimbursement and
           Loan Agreement dated as of February 12, 1998, between
           Thermo Remediation Inc. and Thermo Electron Corporation
           (filed as Exhibit 10.13 to Thermo Remediation Inc.'s
           Annual Report on Form 10-K for the fiscal year ended
           April 4, 1998 [File No. 1-12636] and incorporated herein
           by reference).
                                    25

<PAGE>


Exhibit
Number     Description of Exhibit

 10.34     Master Guarantee Reimbursement and Loan Agreement dated as of
           February 26, 1998, between The Randers Group Incorporated and Thermo
           Electron Corporation (filed as Exhibit 10.11 to The Randers Group
           Incorporated's Annual Report on Form 10-K for the fiscal year ended
           April 4, 1998 [File No. 0-18095] and incorporated herein by
           reference).

 10.35     Amended and Restated Master Guarantee Reimbursement and Loan
           Agreement dated as of February 26, 1998, between the Registrant and
           Thermo Electron Corporation.

 10.36     Thermo TerraTech Inc. - The Randers Group Incorporated Nonqualified
           Stock Option Plan (filed as Exhibit 10.1 to the Registrant's
           Quarterly Report on Form 10-Q for the quarter ended January 3, 1998
           [File No. 1-9549] and incorporated herein by reference).

 10.37     Incentive Stock Option Plan of the Registrant (filed as
           Exhibit 10(h) to the Registrant's Registration Statement
           on Form S-1 [Reg. No. 33-6763] and incorporated herein by
           reference). (Maximum number of shares issuable in the
           aggregate under this plan and the Registrant's
           Nonqualified Stock Option Plan is 1,850,000 shares, after
           adjustment to reflect share increases approved in 1987,
           1989, and 1992, 6-for-5 stock splits effected in July
           1988 and March 1989, and 3-for-2 stock split effected in
           September 1989.)

 10.38     Nonqualified Stock Option Plan of the Registrant (filed
           as Exhibit 10(i) to the Registrant's Registration
           Statement on Form S-1 [Reg. No. 33-6763] and incorporated
           herein by reference). (Maximum number of shares issuable
           in the aggregate under this plan and the Registrant's
           Incentive Stock Option Plan is 1,850,000 shares, after
           adjustment to reflect share increases approved in 1987,
           1989, and 1992, 6-for-5 stock splits effected in July
           1988 and March 1989, and 3-for-2 stock split effected in
           September 1989.)

 10.39     Deferred Compensation Plan for Directors of the
           Registrant (filed as Exhibit 10(k) to the Registrant's
           Registration Statement on Form S-1 [Reg. No. 33-6763] and
           incorporated herein by reference).

 10.40     Equity Incentive Plan (filed as Exhibit 10.63 to Thermedics Inc.'s
           Annual Report on Form 10-K for the fiscal year ended January 1, 1994
           [File No. 1-9567] and incorporated herein by reference; maximum
           number of shares issuable is 1,750,000 shares, after adjustment to
           reflect share increase approved in 1994).
                                    26

<PAGE>


                               EXHIBIT INDEX


Exhibit
Number     Description of Exhibit

 10.41     Directors Stock Option Plan, as amended and restated effective
           January 1, 1995 (filed as Exhibit 10.39 to the Registrant's Annual
           Report on Form 10-K for the fiscal year ended April 1, 1995 [File No.
           1-9549] and incorporated herein by reference).

 10.42     Thermo TerraTech Inc. (formerly Thermo Process Systems Inc.)- Thermo
           Remediation Inc. Nonqualified Stock Option Plan (filed as Exhibit
           10(l) to the Registrant's Quarterly Report on Form 10-Q for the
           fiscal quarter ended January 1, 1994 [File No. 1-9549] and
           incorporated herein by reference).

           In addition to the stock-based compensation plans of the Registrant,
           the executive officers of the Registrant may be granted awards under
           stock-based compensation plans of Thermo Electron for services
           rendered to the Registrant or to such affiliated corporations. The
           terms of such plans are substantially the same as those of the
           Registrant's Equity Incentive Plan.

 10.43     Restated Stock Holdings Assistance Plan and Form of Executive Loan
           (filed as Exhibit 10.42 to the Registrant's Annual Report on Form
           10-K for the fiscal year ended March 29, 1997, and incorporated
           herein by reference).

 13        Annual Report to Shareholders for the fiscal year ended April 4, 1998
           (only those portions incorporated herein by reference).

 21        Subsidiaries of the Registrant.

 23        Consent of Arthur Andersen LLP.

 27.1      Financial Data Schedule for the year ended April 4, 1998.

 27.2      Financial Data Schedule for the year ended March 30, 1996
           (restated for the adoption of SFAS No. 128).

 27.3      Financial Data Schedule for the quarter ended June 29,
           1996 (restated for the adoption of SFAS No. 128).

 27.4      Financial Data Schedule for the quarter ended September
           28, 1996 (restated for the adoption of SFAS No. 128).

 27.5      Financial Data Schedule for the quarter ended December
           28, 1996 (restated for the adoption of SFAS No. 128).

 27.6      Financial Data Schedule for the quarter ended June 28,
           1997 (restated for the adoption of SFAS No. 128).

                                    27