Regulations for Prevention of Groundwater Pollution (Structural Standards)

Regulations for the prevention of groundwater contamination based on the Water Pollution Control Law

Last update date April 1, 2024

Effective regulations for the prevention of groundwater pollution

In order to prevent groundwater contamination by the harmful substances listed in the following table, the installers of facilities that manufacture, use, treat, and store harmful substances are required to establish standards for structures, equipment, and usage to prevent underground penetration. Regulations have been established in the Water Pollution Control Law that require compliance, periodic inspections, and record and preservation of the results (enforced on June 1, 2012).

Standards for Structure
Periodic inspection
Recording and storing results of periodic inspections

List of Hazardous Substances

Table Hazardous substances (Article 2 of the Ordinance)
No.	Hazardous substances
１	Cadmium and its compounds
２	Cyanide compounds
３	Organic phosphorus compounds (limited to palation, methylparation, methyl dimeton and EPN)
４	Lead and its compounds
５	Hexavalent chromium compounds
６	Arsenic and its compounds
７	Mercury and alkyl mercury and other mercury compounds
８	Polychlorinated biphenyl (PCB)
９	Trichloroethylene
10	Tetrachloroethylene
11	Dichloromethane
12	Carbon tetrachloride
13	1,2-dichloroethane
14	1,1-dichloroethylene
15	1,2-dichloroethylene
16	1,1,1-trichloroethane
17	1,1,2-trichloroethane
18	1,3-dichloropropene
19	Chiuram
20	Zimazine
21	Thiobencarb
22	Benzene
23	Selenium and its compounds
24	Boron and its compounds
25	Fluorine and its compounds
26	Ammonia, ammonium compounds, nitrite compounds and nitrate compounds
27	Vinyl chloride monomer (chloroethylene)
28	1,4-dioxane

Standards for Structure, Equipment, and Methods of Use of Hazardous Substance Use Specific Facilities and Hazardous Substance Storage Designated Facilities (Article 12-4 of the Act)

Scope of structure and equipment
Structures and equipment to which the standards are applied

Floor and surroundings (Article 8-3 of the Regulations)

The floor and surroundings of the installation location of designated hazardous substance use facilities and designated hazardous substance storage facilities must be materials and structures that can prevent the infiltration of water containing harmful substances into the underground and outflow of the facilities. .

Piping, etc. (Article 8-4 of the Regulations)

When installing piping (*) attached to the main body of a designated facility for using harmful substances or designated facility for storing harmful substances on the ground, use a material and structure that can prevent leakage of water containing harmful substances, or leakage It must be a structure that can confirm leakage if there is.
In addition, when installing underground, it shall be a material and structure that can prevent leakage of water containing harmful substances and penetration into the underground, or a structure that can confirm leakage etc. if there is leakage or penetration into the underground Must have.
※Pipes, fittings, flanges, valves, pump equipment, etc. that are connected to the facility and flow water containing harmful substances flows.

Drainage, etc. (Article 8-5 of the Regulations)

Drainage drains (*) of drainage systems attached to the main body of designated facilities for using harmful substances and designated facilities for storing harmful substances must be materials and structures that can prevent the penetration of water containing harmful substances into the basement. .
※Drainage ditches, drains, drains, drain pumps, etc. that are connected to the facility and containing harmful substances flow.

Underground storage facilities (Article 8-6 of the Regulations)

Of the underground storage facility itself and the accompanying piping, the underground storage facility itself must be a material and structure that can prevent leakage of water containing harmful substances and penetration into the basement.

Method of use (Article 8-7 of the Regulations)

Acceptance, transfer, distribution, etc. of water containing harmful substances pertaining to designated facilities that use harmful substances and designated facilities for storing harmful substances shall be performed by a method that does not scatter, run out, or penetrate underground, and harmful substances. The facility must be properly operated, such as checking the supply status of water containing water and the operation of equipment.
In the event that water containing harmful substances is leaked, measures shall be taken to prevent leakage immediately, and water containing the leaked harmful substances shall be collected and reused, or properly treated so as not to hinder the living environment conservation.
Businesses need to create management guidelines that describe usage, inspection method, number of inspections, etc.
Guidance for development of management guidelines (Ministry of the Environment website) (outside site)
Example of preparation of management guidelines (Ministry of the Environment website) (outside site)

Criteria for judging water that does not contain harmful substances

If the concentration of harmful substances in wastewater from the cleaning facility can be less than the concentration in the following table by washing equipment with harmful substances several times and collecting waste liquids in separate containers, etc. Can be determined to be water that does not contain harmful substances. In that case, structural standards and periodic inspections are not applied to pipes, drains, etc., because water containing harmful substances does not flow.
However, structural standards and periodic inspections are applied to the floor and surrounding areas of the cleaning facility, regardless of the concentration of harmful substances.

Table Concentrations that are not considered to be detected
Types of Hazardous Substances	Concentration	Types of Hazardous Substances	Concentration
Cadmium and its compounds	Less than 0.001mg/L	1,2-dichloroethylene	Less than 0.004mg/L (for each cis body and trans body)
Cyanide compounds	Less than 0.1mg/L	1,1,1-trichloroethane	Less than 0.0005mg/L
Organic phosphorus compounds (limited to palation, methylparation, methyl dimeton and EPN)	Less than 0.1mg/L	1,1,2-trichloroethane	Less than 0.0006mg/L
Lead and its compounds	Less than 0.005mg/L	1,3-dichloropropene	Less than 0.0002mg/L
Hexavalent chromium compounds	Less than 0.01mg/L	Chiuram	Less than 0.0006mg/L
Arsenic and its compounds	Less than 0.005mg/L	Zimazine	Less than 0.0003mg/L
Mercury and alkyl mercury and other mercury compounds	Less than 0.0005mg/L	Thiobencarb	Less than 0.002mg/L
Alkyl mercury compounds	Less than 0.0005mg/L	Benzene	Less than 0.001mg/L
Polychlorinated biphenyl (PCB)	Less than 0.0005mg/L	Selenium and its compounds	Less than 0.002mg/L
Trichloroethylene	Less than 0.002mg/L	Boron and its compounds	Less than 0.2mg/L
Tetrachloroethylene	Less than 0.0005mg/L	Fluorine and its compounds	Less than 0.2mg/L
Dichloromethane	Less than 0.002mg/L	Ammonia, ammonium compounds, nitrite compounds and nitrate compounds	Ammonia nitrogen: Less than 0.7mg/L, nitrite nitrogen: Less than 0.2mg/L, nitrate nitrogen: Less than 0.2mg/L
Carbon tetrachloride	Less than 0.0002mg/L
1,2-dichloroethane	Less than 0.0004mg/L	Vinyl chloride monomer (chloroethylene)	Less than 0.0002mg/L
1,1-dichloroethylene	Less than 0.002mg/L	1,4-dioxane	Less than 0.005mg/L

Certification method specified by the Minister of the Environment based on the provisions of Article 6-2 of the Water Pollution Control Law Enforcement Regulations (Ministry of the Environment website) (outside site)

Periodic inspection (Article 9-2-2 of the Regulations)

Periodical inspections of hazardous substance use specific facilities and designated hazardous substance storage facilities are conducted by visual inspection (excluding cases where visual inspection is difficult and equipment is used) and the floor and surroundings of the installation site of the facility. Underground storage facilities, such as the main body of the facility, the accompanying pipes, drains, etc., must be performed in items and frequency according to the structural standards.
If the inspection confirms that abnormality or leakage of water containing harmful substances or penetrates underground, necessary measures such as repairs must be taken immediately.

Recording and preservation of the results of periodic inspections (Article 9-2-3 of the Regulations)

When a periodic inspection is performed, the following items 1 to 5 must be recorded and stored for 3 years.
Example of preparation of periodic inspection table (Ministry of the Environment website) (outside site)
①Designated hazardous substance use facilities and designated hazardous substance storage facilities that have been inspected
②Date of inspection
③Method and Results of Inspection
④Name of the person who conducted the inspection and the person in charge of the inspection
⑤If repairs or other necessary measures are taken based on the results of the inspection, the details will be taken.
In addition, regardless of periodic inspections, if abnormalities or leakage of water containing harmful substances or penetration into the underground are confirmed at facilities that use harmful substances or designated hazardous substances storage facilities, the following items 1 to 5 are recorded. Please record and try to keep it for 3 years.
①Specific facilities for the use of harmful substances and designated facilities for the storage of harmful substances whose abnormalities have been confirmed
②Date on which abnormalities were confirmed
③Details of abnormality, etc.
④Name of the person who confirmed the abnormality
⑤If repairs or other necessary measures have been taken, the contents of such measures.