Idea Transcript
Soil and Groundwater
The Environment of Tokyo 2011
●土壌汚染対策法の概要
Soil is an important factor that constitutes the environment together with air and water, and plays an important role as the basis of survival of organisms including human beings. In recent years, soil contamination by volatile organic compounds (VOCs), heavy metals, and other chemical substances has been revealed. Since there is a close relationship between soil contamination and groundwater contamination and both have a long-term effect, the social concerns are high and effective measures are essential. Therefore, in order to prevent impairment to human health from soil contamination, TMG established regulations concerning measures on soil contamination in the Tokyo Metropolitan Environmental Security Ordinance, and has been providing instruction since October 2001. Moreover, the Soil Contamination Countermeasures Law was enacted and enforced in February 2003. The law was recently revised and the revised version came into force in April 2010.
In the late 1960s, soil contamination due to hexavalent chromium included in chromite ore residue was revealed at former chemical factory sites and other locations in Koto Ward and Edogawa Ward. Since then, soil contamination in urban areas has become a serious issue.
Measures against Soil Contamination by Ordinances and Laws In October 2001, according to the Tokyo Metropolitan Environmental Security Ordinance, TMG required hazardous substance handling facilities, and personnel perform largescale modifications of land, to implement a “soil contamination state investigation.” They would be obligated to perform
Landowners, etc.
Investigation and report
(property owners, managers, and occupants)
(investigation by a designated research agency)
Unsuitable for the specified standards
Unsuitable for the specified standards
(it is possible that voluntarily application for assignment)
When there is a possibility of a health hazard
- The Governor directs implementation of measures, such as decontamination, to the persons who caused the contamination (the land owner, etc., if the people who caused the contamination are unknown).
- Those who change the configuration of the land shall submit plans to the Governor. - If the changes are not appropriate, the Governor orders them to change the plan.
Creation of Greenery and Natural Environment Conservation
● Measures required from the point of view of risk by direct ingestion of the soil “No Trespassing” (“Keep Out”) signs, paving, banking, soil replacement, and removal of contaminated soil (decontamination)
Environmental Assessments
- Regulations on the carrying out of soil within areas (prior notification, order to change the plan, or order to take appropriate measures for those who violate the transportation standards or treatment standards) - Obligation to issue and save control slips regarding soil contamination - Transportation to facilities that are authorized as contaminated soil management contractors
Number of Notifications at the Time of Closing Factories (Article 116 of the Ordinance)
Provision of Information and Promotion of Cooperation Surveys and Researches
Number of Notifications at the Time of Modifying Land (Article 117 of the Ordinance)
350
700
300 250
Soil contamination state investigation
200
Dif usion of Pollution Prevention Program
150
Completion report
100 50
No. of notifications
No. of notifications
Implementation of measures to prevent diffusion of contamination
Soil contamination state investigation
Contaminated or likely to be contaminated
When the removal of contaminated soil (decontamination) is performed, the designation of the area is canceled.
● Measures required from the point of view of risk by ingestion of groundwater Measurement of the groundwater quality, encapsulation process, containment (in-situ, leaching control system, and pollution cutoff work), prevention of expansion of groundwater contamination, and removal of contaminated soil (decontamination)
Storage and passing on of records (Article 28)
When it is confirmed that contaminated soil is causing the contamination of the atmosphere and groundwater, and is also resulting in damage to human health or in the possibility of damage (Article 114)
Implementation of treatment of contaminated soil
Areas where groundwater contamination has been detected (Article 115)
Soil contamination state investigation
When closing or removing factories or designated worksites (Article 116)
Conservation of Water Environment
Limitations on changing the configuration of the land
Measures to decontaminate
Total: 5,231 cases
Those who Investigation purchase of land history the land
Land modification of 3,000 m2 or more (Article 117)
Protecting the Living Environment: Noise/Vibration/ Offensive Odors
Areas that require application when changing the configuration
- Designation and public announcement by the Governor - Indication and access to registers
When measures are performed except for removal of contaminated soil (decontamination)
Potential contamination No potential contamination
Total: 2,563 cases
Soil and Groundwater
When there is no possibility of a health hazard
Designation of areas, etc. Areas requiring measures
Chemical Substance Control
Investigation not covered by any law
(investigation by a designated research agency)
3,767 Contaminated Not contaminated
Those who modify land
Air Pollution Control
- When discontinuing the use of specified facilities where hazardous substances are used - When changing the configuration of potentially contaminated land over 3,000 m2 - When there is a possible health hazard, which may be caused by soil contamination
28%
1679
Waste Management and Resource Recovery
■Scheme
1,464
884
Hazardous substance-handling facilities
Heavy metals that may accumulate in higher concentrations in the surface of soil over a long period of time (standard soil content)
Health hazards caused by groundwater contamination
Standard solution items of the soil environmental quality standards established from the aspect of ingestion of groundwater, etc. (standard soil solution volume)
Condition of Contamination at the Time of Land Modification (Article 117 of the Ordinance)(October 2001 to March 2010)
34%
●Process of Soil Contamination Treatment according to the Ordinance
Health hazards caused by direct ingestion of contaminated soil
(Specified Hazardous Substances)
(URL) http://www.kankyo.metro.tokyo.jp/chemical/soil/index.html (in Japanese)
Condition of Contamination When Factories Closed (Article 116 of the Ordinance)(October 2001 to March 2011)
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■Applicable Substances
treatment of the contaminated soil, if contamination was confirmed by the investigation. As a result of performing these investigations, which was implemented by the hazardous substance handling facilities when a factory was closed, soil contamination was detected in about 34% of the soil. Moreover, in an investigation of the land-use history, it was found that about 28% of the land was potentially contaminated when you modified large scale land. The national government enacted the Soil Contamination Countermeasures Law in February 2003 (revised in April 2010). After the Soil Contamination Countermeasures Law was enacted, TMG specified 146 locations as designated districts and measure-required districts. Of these, 95 locations have been removed from the designation list (as of the end of March, 2011).
Soil Contamination Issues in Tokyo
Climate Change
● Outline of the Soil Contamination Countermeasures Law
600 500
Investigation of land-use history
400
Soil contamination state investigation
300
Dif usion of Pollution Prevention Program
200 100
0 FY2001
FY2002
FY2003
FY2004
FY2005
FY2006
FY2007
FY2008
FY2009
FY2010
References
Completion report
0 FY2001
FY2002
FY2003
FY2004
FY2005
FY2006
FY2007
FY2008
FY2009
FY2010
(The number of notifications submitted in 2001 was the total for 6 months, as the Tokyo Metropolitan Environmental Security Ordinance was enacted on October 1, 2001.)
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Soil and Groundwater ●Countermeasures against Soil Contamination ✔ Forum on Soil Decontamination Technology
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close-up
What is soil contamination?
-Understanding the health risks caused by soil pollution -
Generally, the cost of decontaminating contaminated soil is high. Companies, particularly those with limited financial resources, are searching for low-cost decontamination technologies that can be applied to smaller areas of land. Therefore, since July 2004, TMG has held the Forum on Soil Decontamination Technology every year. This aims to promote competition in the soil decontamination market, to accelerate development of low-cost decontamination technologies, and to provide companies with information regarding these technologies.
The soil forms the surface of the land (ground) we live on and is one of the indispensable components needed to sustain our lives on earth. It sometimes contains hazardous substances produced by different factors. These substances in turn might cause serious damage to human health (health risk) when they are absorbed by the human body through the direct intake of dispersed substances in the air, the intake of ground water into which these substances are dissolved, etc. In order to deal with this issue, certain standards and measures were established within the laws and ordinances to prevent negative effects on human health by these substances in the soil. Soil contamination is generally defined as the condition of the soil wherein the concentration of an accumulated hazardous substance exceeds the standards set under the laws or ordinances as a result of man-made causes such as the leakage of chemical agents and wastewater into the soil. It can also refer to the general state where the concentration of hazardous substances in the soil is above the standards due to not only man-made causes, but also natural causes including the composition of soil. The laws and ordinances require that if soil contamination is found and there is a possibility that a hazardous substance can reach the human body through soil dispersion, the intake of ground water, etc., measures to block those pathways in order to protect human health should be implemented.
(URL)http://www.kankyo.metro.tokyo.jp/chemical/event/soil_forum/index.html (in Japanese)
◆ Percolation of hazardous substances into soil caused by improper storage and handling (anthropogenic causes)
✔ Selection of Simple and Quick Measurement Technologies In general, not only the cost of treating contaminated soil, but also the cost of investigating and analyzing contaminants is high. The dissemination of low-cost investigative technologies is an important issue in reducing the costs of measures against soil contamination. TMG has publicly sought simple and quick analytical technologies (simplified analytical methods) of a practical level with the aim of reducing the cost of analyzing contaminants and shortening the investigating period, and excellent technologies are selected based on the result of demonstration experiments. TMG selected 13 technologies for heavy metals in FY2005, 4 technologies for Volatile Organic Compounds (VOCs) in FY2006, 18 technologies for heavy metals and 3 technologies for VOCs in FY2007, and 7 technologies for heavy metals in FY2009. These selected simple analytical methods can be used for a portion of soil investigations based on the Ordinance.
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Groundwater accounts for approximately 10% of water usage in Tokyo. Groundwater is not only important as a water resource, but is also an indispensable part of water circulation. When groundwater is pumped excessively, the land will sink. Since groundwater flows gradually, once the groundwater is contaminated, the effect will continue for a long time. Therefore, preservation of groundwater and its quality control are an important issue for the protection of the whole environment of Tokyo. TMG has conducted groundwater quality investigation in all districts in Tokyo since the wells used as water sources were discovered to be contaminated with trichloroethylene. According to the results of an investigation (outlook
(URL)http://www.kankyo.metro.tokyo.jp/water/groundwater/investigation. html (in Japanese)
● Countermeasures against Groundwater Contamination (Flow Chart) Groundwater quality investigation based on the Water Pollution Control Law
◆ Soil that contains a large amount of naturally existing arsenic, lead, etc. (natural causes)
Environmental investigations conducted by cities
Outlook investigation ・Over a period of 4 years 260 blocks will be investigated starting 2010
Soil and groundwater investigation based on the ordinance
Notes Measures against cutting off and properly
Measures to reduce the concentration
Follow-up investigations of groundwater contamination
Continuous monitoring investigation ・Periodic water quality investigation at contamination-confirmed areas
Measures applicable when the content of a hazardous substance in the soil does not Measures for non-conforming content conform to the standards Measures applicable when the solution volume of a hazardous substance in the soil does not conform to the standards
Removal level of a hazardous substance to the measures appropriate standards
Insolubilization
After insolubilization
Soil with non-conforming solution volume Chemical agent injection plant
Injection of a chemical agent
Insolubilized soil
Investigation for identification of the contamination source
(Example: In-situ insolubilization)
Sheeting, paving, landing up, etc.
Groundwater level
Air Pollution Control Chemical Substance Control
Insolubilization is a measure to make a hazardous substance insoluble in water by injecting a chemical agent into the soil containing non-conforming solution volume. In addition, there is the “Insolubilization – burying again” measure wherein the non-conforming soil is excavated and then a hazardous substance is insolubilized at a plant etc. to backfill the same location.
Flow of groundwater
Protecting the Living Environment: Noise/Vibration/ Offensive Odors
Creation of Greenery and Natural Environment Conservation
Measures for non-conforming solution volume
During insolubilization
Waste Management and Resource Recovery
Conservation of Water Environment
Investigation of areas surrounding contaminated wells Control control the channels through which a hazardous measures substance is taken into the human body
Climate Change
Soil and Groundwater Soil contamination
✔ Promotion of Measures against Soil Contamination Despite the progress made by landowners and entities responsible for the contamination in terms of soil contamination countermeasures, there are some cases where the land remains unused. This is due to the existence of or concern for the possible existence of soil contamination resulting from difficulties in implementing an investigation or measure on the part of small and medium-sized companies already laden with numerous burdens. In such cases, there are concerns about the impact on the surrounding environment including the dispersing of contaminated soil, the permeation of contaminants into ground water, etc. In order to facilitate soil contamination countermeasures for this type of unused land, TMG created the “Soil Contamination Countermeasure Guidelines for Small and Medium-sized Companies” (FY 2010). Its purpose was to provide small and medium-sized companies intending to implement certain measures with basic knowledge on health risks due to soil contamination as well as on the investigation of soil contamination, and clearly illustrate the specific procedures to select reasonable countermeasures.
investigation) in FY2009, the environmental quality standards were not met in 6 of the 71 investigated points. Moreover, based on the Water Pollution Control Law, TMG has been controlling or providing instruction to business facilities treating trichloroethylene regarding the underground saturation prevention of hazardous substances. According to the Tokyo Metropolitan Environmental Security Ordinance, if groundwater contamination is detected at a site, the owner of adjacent facilities is required to perform investigations concerning the soil contamination responsible for the groundwater contamination. If contamination is detected in the area, they are required to decontaminate both soil and groundwater.
Factories / Facilities
(URL)http://www.kankyo.metro.tokyo.jp/chemical/soil/information/analysis/ index.html (in Japanese)
Countermeasures against Groundwater Contamination
On-site investigation
Guidance on decontamination Ordering the introduction of decontamination measures according to the Water Pollution Control Law Implementation of decontamination
Control measures
Environmental Assessments
Measures for non-conforming solution volume
Confirmation of the effectiveness of the decontamination
In-situ purification Chemical agents and nutrient salts Injection well
Soil with non-conforming elution volume
Treatment tank Water draining with monitoring
Injection
Groundwater level
Microbial degradation Pumping well
Flow of groundwater
The measures for in-situ purification can be categorized into the following three groups. In-situ leaching: The hazardous substances are recovered through the use of gas or ground water. In-situ degradation: The hazardous substances are degraded by chemical reactions or microbial activities. In-situ soil washing: The hazardous substances are dissolved into surfactants and recovered.
Removal measures Measures for non-conforming content Measures for non-conforming solution volume
During excavation
Excavation and removal
After excavation Burying again
Excavation
Groundwater level
Non-conforming soil
The non-conforming soil is excavated and removed and the site is backfilled with the conforming soil. The excavated soil is treated properly in or out of the enclosure. Due caution needs to be exercised in this measure so that the hazardous substances will not disperse into the surroundings when transported or treated.
Conforming soil
Groundwater level
Provision of Information and Promotion of Cooperation
(Example: In-situ degradation, Left diagram: Bioremediation)
Removal measures Measures for non-conforming content Measures for non-conforming solution volume
Excerpts from “Soil Contamination Countermeasures Guideline for Small and Medium-sized Companies” (URL) http://www.kankyo.metro.tokyo.jp/chemical/soil/information/ guideline.html (in Japanese)
● Investigation Methods for Groundwater Name of Investigation
Purpose of Investigation
Outlook investigation
To understand the outlook of the groundwater and water quality in the entire Tokyo area
Investigation of areas surrounding contaminated wells
To confirm the scope of the area in the block where new contamination has been detected as a result of the outlook investigation
Continuous monitoring investigation
Continuous monitoring after contamination has been detected
Contents of Investigation One point check per block Check of the water quality of the wells around the block where the new contamination was detected Periodic check of the water quality of the contaminated well
● Transition of Substances Exceeding the Environmental quality Standards No. of points checked
㻔㻗
Fluoride
(Outlook investigation)
Surveys and Researches
Boron
㻔㻕
Hexavalent chromium
㻔㻓
Nitrate nitrogen and nitrite nitrogen Arsenic
㻛 㻙
References
Lead
㻗
Others/VOCs
㻕
Trichloroethylene
㻓 㻔㻜㻜㻛 㻃 㻔㻜㻜㻜 㻃 㻕㻓㻓㻓 㻃 㻕㻓㻓㻔 㻃 㻕㻓㻓㻕 㻃 㻕㻓㻓㻖 㻕㻓㻓㻗 㻃 㻕㻓㻓㻘 㻃 㻕㻓㻓㻙 㻃 㻕㻓㻓㻚 FY
㻕㻓㻓㻛
㻕㻓㻓㻜
Tetrachloroethylene
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