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Release: April 20, 2004

NGK Conducts Soil and Groundwater Examination on the
Site of its Manufacturing Subsidiary

NGK INSULATORS, LTD. (President & COO: Shun Matsushita; Head Office: Nagoya, Aichi, Japan) has voluntarily carried out a test for soil and groundwater on the premises under its basic policy concerning the environment. The result showed contaminants exceeding the environmental quality standard on the site of NGK Printer Ceramics Co., Ltd. (President: Takayuki Mori; Head Office: Komaki, Aichi, Japan), NGK's subsidiary manufacturing electronic components. Accordingly, the company reported to Komaki City and Aichi Prefecture on April 19 and has started taking countermeasures as well.

1. Location of Examination

  • Subsidiary: NGK Printer Ceramics Co., Ltd. (owned solely by NGK Insulators, Ltd.)
  • Address: 434-3 Aza Gotanda, Ooaza Shimozue, Komaki, Aichi, Japan
  • Site Area: 35,469 m2
  • Number of Employees: approx. 260
  • Business: Manufacture of ceramic electronic components

2. Methods of Examination

  • Preliminary Survey: Soil gas analysis (Period: June to July 2003)
  • In-Depth Examination: Soil boring investigation (13 locations), analysis of groundwater pumped up from wells (8 locations), geological survey (Period: July 2003 to March 2004)

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3. Results of Examination

  • Near the site of the former solvent recovery equipment
    Volatile chlorinated organic compounds exceeding the environmental quality standard (hereinafter "EQS") were detected from both soil and groundwater.
  • Near the perimeter of the site
    Volatile chlorinated organic compounds exceeding EQS were discovered from groundwater.

Analytical Value (Maximum Value of Detected Substances)

Detected Substances EQS(mg/L) Former Solvent Recovery Equipment Site Site Perimeter
Soil (mg/L) JWater (mg/L) Soil (mg/L) Water (mg/L)
Substances used Trichloroethylene 0.03 0.089
(X 3)
(X 11)
(X 5)
Tetrachloroethylene 0.01 0.16
(X 16)
(X 23)
(X 7)
Degradation Products cis-1,2-
0.04 0.11
(X 2.8)
(X 16)
(X 17)
0.02 0.03
(X 1.5)
** 1,2-Dichloroethane 0.004 Below
(X 9)
(X 11)

(A figure in a parenthesis is the ratio to EQS)

**As there is no fact of using 1,2-Dichloroethane, a cause of its detection is under investigation.
* Number of locations exceeding EQS for soil contamination: 6 out of 23 locations
* Number of locations exceeding EQS for groundwater pollution: 10 out of 20 locations

4. Cause of Pollution (Presumption)

NGK Printer Ceramics Co., Ltd. used to manufacture ceramic packages using a solvent of volatile chlorinated organic compounds in a preparation process of ceramic powder, and utilized solvent recovery equipment to collect evaporated gas. A part of the equipment, a concrete catchment pit, had a crack in it and leaked organic solvent that remained in soil afterwards.

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5. Summary in Chronological Order

1986-1998: Used Trichloroethylene and Tetrachloroethylene as a solvent in a preparation process of ceramic package's raw materials. Collected the evaporated gas with solvent recovery equipment.
September 1998: Disposed of solvent recovery equipment due to discontinuance of ceramic packages.
February 2001: Removed a catchment pit and a side ditch in the course of plant improvement.
June 2003: Initiated a soil survey on a voluntary basis in accordance with enforcement of the Soil Contamination Countermeasures Law (February 2003).
June-July 2003: Carried out a soil gas analysis as a preliminary survey. Due to the result showing a sign of contamination, an in-depth examination started.
March 2004: Completed the examination and analysis discovering soil and groundwater pollution. Discussed and planned countermeasures.
April 2004: Reported the result of the research and the countermeasures to Komaki City and Aichi Prefecture.

6. Outline of Countermeasures

As an emergency measure, NGK started with preventing polluted groundwater from flowing out of the premises. As a permanent measure, the company takes steps to purify soil and groundwater on the site.

  • Emergency Measure
    Install a "barrier well" (5 locations, 8 wells in total) at the perimeter on the downstream side of groundwater. Prevent pollutants from flowing outside by pumping groundwater up from the wells and properly treat discharged water by removing contaminated groundwater. (Started from March)
  • Permanent Measure
    Purify an upper layer of contaminated earth by gas absorption and a lower layer by lifting groundwater and using an aeration method with injection of oxidizing agent (hydrogen peroxide solution) which accelerates resolution of chlorinated organic compounds. Emitted gas will be absorbed and treated with activated carbon. (Initiated from April) NGK will keep monitoring and regularly report the result of these countermeasures.
  • Preventative Measure
    The company totally abolished the use of Trichloroethylene and Tetrachloroethylene in September 1998.

7. Influence on Health

NGK considers that there would be no problem if people did not drink the well water on a daily basis.

8. Report to Locals

  • April 20: Outline the incident to representatives and offices in the neighboring districts.
  • April 28: Hold a meeting to explain to local residents at the Komaki Kinrou Center (Ooaza Kamizue, Komaki, Aichi), starting from 7 p.m.

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