Support for Local Environmental Conservation

To realize a sustainable society, HEPCO Group, as a company with deep roots in Hokkaido with its abundant nature, will strive to implement environmental conservation measures at our power plants, appropriately control and dispose of chemical substances, and take other steps to reduce the burden on the environment in this region.

Environmental Conservation Initiatives in HEPCO Group Power Generation Operations

HEPCO Group power plants are built after preliminary investigations have been conducted and estimates prepared of the impact that such construction will have on the environment. We then select equipment and methods for minimizing our environmental footprint. We have also entered into pollution prevention agreements with local governments near our thermal, geothermal and nuclear power stationsso that we also strive to prevent pollution by continuously monitoring gas and water discharges while the stations are operating. Moreover, in accordance with environmental laws and regulations,we dispose of hazardous chemical substances and faithfully survey amounts of chemical substances used.
These activities enable us to operate our business in harmony with Hokkaido's nature as well as its living environment.

Key environmental protection measures applied during power station construction

	Examples
Terrestrialenvironment	Restrictions on areas where the topography can be altered or logging carried out Reduction of on-site work by assembling large machinery at the plant site Measures for protecting rare insects, raptors and other fauna Greening activities that take into consideration the surrounding natural vegetation
Water environment	Selection of construction methods that do not disturb the habitat or homes of living creatures Preventing adverse impact on water quality by treating water to be discharged (pH, SS*1)

Key environmental protection measures applied during thermal power station operation

	Items monitored
Atmospheric environment	Sulfur oxide (SoX) - Nitrogen oxide (NOX) Particulate matter
Water environment	Wastewater quality (pH, COD*2, SS, etc.) Temperature differential between condenser cooling water intake and discharge

*1 SS:Suspended Solids (amount of particulate matter 2 mm in diameter or smaller that is suspended in or floating on water)
*2 COD:Chemical Oxygen Demand (conversion of the amount of oxidizing agent necessary for decomposing organic matter to the amount of oxygen)

PCB Neutralization Initiatives

In accordance with relevant laws and regulations, HEPCO Group securely stores and manages PCBs at our business facilities in Hokkaido.
We completed the outsourcing of disposal of high-level PCBs to the Japan Environmental Storage & Safety Corporation's Hokkaido PCB Treatment Office within the time period set (end of FY2023). In addition, we properly treat and dispose of low-level PCBs as well.

Storage status of PCB and other waste (March 31, 2024)

Waste material	Low-level PCBs
Insulating oil*1	3 kl
Transformers	16 units
Condensers	13 units
Rags and other contaminated objects	1,639 kg
Small-and medium-sized machinery, etc.*2	78 units
Fluorescent lamp ballast	-

*1Amount stored in drum cans
*2Bushings, instrument transformers, circuit breakers, relays , etc.

HEPCO Tomakomai Recycling Center

In Tomakomai City, we established a low-level PCB neutralization facility certified by the Minister of the Environment. Since August 2017, we have been treating and disposing of our own PCB-contaminated medium- and large-sized equipment.

HEPCO Tomakomai Recycling Center

Addressing Asbestos Issues

Facilities with asbestos sprayed coatings are periodically checked for safety, and promptly removed or other abatement measures taken as necessary.
In addition, molded objects, which contain non-friable asbestos, are replaced with non-asbestos products when repairs are made or other maintenance performed.

Main uses of asbestos in buildings and facilities (FY2024)

Waste material	Waste material Location and usage
Spray containingasbestos	Used as acoustic absorbent material, thermal insulation and fireproof material in buildings
Spray containingasbestos	2 buildings
Construction material	Used in fireproof boards, flooring and other materials for buildings
Construction material	Contained in construction materials used prior to August 2006. After that date, products containing asbestos have not been used.
Soundproofing material	Soundproofing material for transformers (transforming facilities)
Soundproofing material	54
Asbestos cement pipe	Pipe material for underground lines (power transmission facilities)
Asbestos cement pipe	Route length: approx. 3.2 km
Thermal insulating material	Power generation facilities (thermal power)
Thermal insulating material	Volume of remaining asbestos-containing products: approx. 2,500 m3 (approx. 6% of total)
Cushioning material	Suspension insulators for power transmission and other facilities
Cushioning material	Number of remaining asbestos-containing products: approx. 607,900 (approx. 24% of total)
Thickening material	Overhead power lines
Thickening material	Length of lines to which corrosion preventive compound has been applied: approx. 183.0km (approx. 2.3% of total overhead power line length)
Sealant & joint sheets	Power generation facilities (thermal & nuclear)
Sealant & joint sheets	Number of remaining asbestos-containing products: (Thermal) approx. 23,900 (approx. 26% of total) (Nuclear) approx. 34,300 (approx. 62% of total)

Appropriate Management of Specified Chemical Substances (Compliance with PRTR Act)

In accordance with the Act on Confirmation, etc. of Release Amounts of Specific Chemical Substances in the Environment and Promotion of Improvements to the Management Thereof (PRTR Act), HEPCO verifies the quantities of specified chemical substances released or transferred, and we properly control and effectively manage these substances as we endeavor to reduce the amount handled. HEPCO notifies the Japanese government when we handle a specified or larger quantity of any of these designated chemical substances.

PRTR Act Notifications (FY2024)

Substance	Notifying plant		Environmental emissions		Quantity transferred	Use or source
Substance	Number of plants	Type	Atmosphere	Water areas	Quantity transferred	Use or source
Dioxin	1	Other	0.01 mg-TEQ	0	0	Waste incinerator
1,3,5-Trimethylbenzene	1	Other	5.29 kg	0	0	Fuel for power supply vehicle
Toluene	1	Thermal	3,000 kg	0	0	Fuel for generating power
Polychlorinated biphenyl	1	Other	0	0	0.02 kg	PCB waste treatment at PCB waste treatment facilities
Methylnaphthalene	4	Thermal	838 kg	0	1.10 kg	Fuel for generating power
Methylnaphthalene	1	Nuclear	200 kg	0	0	Fuel for auxiliary boiler

*With the exception of dioxins, totals have been tabulated for substances with an annual volume of 1 ton or more (0.5 t or more for specified Class 1 Designated Chemical Substances).