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SustainabilityEnvironmentResource Circulation
Resource Circulation
All employees of POC participate in 3R (Reduce, Reuse, Recycle) promotion in a bid to reduce waste in daily activities, and starting from FY 2006, we have been implementing zero-emission initiatives throughout the company.
Recycling of Construction Generated By-products
Effective recycling of construction generated soil is an important issue for the construction industry. We have established a wide-area network of shipping bases across the nation and are promoting the effective utilization of soil and sand. We are also working with the steel industry to develop new environmentally-friendly dredging technology to explore the new use of dredged soil.
Construction Generated Soil and Soil Contamination
In 2014, we expanded our Ichikawa office in Chiba Prefecture, which undertook marine transportation of construction soil for utilization as a reclamation material, and opened the Ichikawa Soil Reuse Center as a facility to receive construction generated soil and contaminated soil. The center makes effective recycling of the received contaminated soil by converting it into raw materials for cement, etc.
We opened a new Soil Reuse Center in Yokohama in 2017 and another one in Nagoya in 2018. In 2021, the center in Nagoya started reception of contaminated soil. In 2022, we began production and sales of fluidized treated soil (construction sludge recycling business) in Ichikawa. Thus, we are promoting comprehensive/wide-area utilization and appropriate treatment of soil generated in the Kanto and Chukyo regions.
Ichikawa Soil Recycling Center
(Contaminated soil treatment
business permit:
No.0781001004)
Yokohama Soil Recycling Center
(Contaminated soil treatment
business permit:
No.0850001003)
Nagoya Soil Recycling Center
(Contaminated soil treatment
business permit: No.10900010002
Industrial waste disposal division
of labor: Permission
No.064200622304)
Effective Utilization of Soft Soil and Dredged Soil
Dredging works to maintain harbor basins and deepening ships channels in port may generate a large amount of dredged soil. Recycling of the generated soil and sand is an imminent environmental issue for us as a company engaged in dredging. We are developing various technologies to tackle these issues.
Calcia Soil Improvement Technology
Calcia reforming technology improves the physical and chemical properties of dredged soil by mixing the soft dredged soil generated from the port works with the Calcia reforming material (materials for controlling the composition and adjusting the particle size of steelmaking slag from converter system) generated in the steelmaking process.
The Calcia reformed soil made by the Calcia reforming technology can be widely applied in marine constructions such as landfill material, partition embankment material, revetment backfill material, and marine embankment material for repairing route burial. It is expected to shorten the construction period and reduce costs.
Our company has developed a high-performance Calcia reforming technology using short fibers and mud improvement materials and is working on dredged soil recycling at ports.
Calcia Improved Soil Drop Mixing Vessel
As more attention is given to creating a recycling-oriented society, various plans are underway nation-wide to apply the Calcia reforming technology to utilize dredged soil for reclamation work and other projects.
To meet these needs, POC upgraded an existing reclaimer vessel* and equipped it with a system for feeding Calcia reforming material. This "Calcia Drop-Mixer" enables us to obtain the prescribed mixing quality for the material on board and ensures efficient and effective construction.
*Reclaimer vessel: A work vessel used in coastal reclamation etc. The vessel unloads soil and sand (via a backhoe, etc.) transported by a soil carrying vessel, and discharges it to reclamation sites via a conveyor, etc.
*The vessel is jointly owned with Kanmon Kowan Construction Co., Ltd.
Concept
Principles of Drop-Mixing
Dredged soil and Calcia reforming material are mixed when down-dropped from a conveyor belt or a spreader and collided with an iron plate or a slope, etc.
Clay Guard Method
The Clayguard method intercepts water on the sides and bottom of a marine waste disposal site by using soil-based seepage material to prevent hazardous materials from accidentally spreading. The soil-based seepage material is made from construction soil such as dredged clay by mixing it with bentonite and other sub-materials to improve water-tightness. Since no solidifying material is used, the material presents self-compacting and deformation-following properties, and can follow external forces such as ground subsidence and waves and maintains its water-tightness for a long period of time.
Muddy soil Recycling Business
The utilization of muddy soil generated from dredging of rivers and lakes and excavation work on land is also an important issue for us, and we are developing various technologies to solve this problem.
Water-absorbing mud stabilization material "Watoru"
The water-absorbing mud stabilization material "Watoru" is a hydration-treated product made by mixing a special chemical with incinerated paper ash (PS ash) from paper manufacturing sludge generated by papermaking companies. In addition to physical reforming through water-absorbing (with an instantaneous reforming effect), it also exhibits chemical reforming ability over time (with gradual strength development).
The material received the Excellent Award in the Infrastructure Technology Development Award in 2021 and is highly recognized as an effective recycling material.
*Watoru is a product developed by JAIWAT Co., Ltd., POC's wholly owned consolidated subsidiary, and is produced in a JAIWAT’s manufacturing plant named “Sodegaura Eco-land” located in Sodegaura city, Chiba Prefecture ,JAPAN.
JAIWAT takes full responsibility of material procurement, manufacture, distribution and quality control of Watoru.
Food Waste Recycling Business
This business processes and sells compost materials made from organic waste discharged from food-related companies, etc.
Characteristics of the business
- With the automatic agitator (scoop-type) and the forced air circulation (aeration), collected food waste is subject to primary fermentation for about 1 month, and then further fermentation and maturation for about 3 months to produce complete compost.
- Since the Miki Composting Center is located near the Hanshin district with concentration of many food-related companies and easily accessible from interchanges of the expressway, it contributes to the reduction of waste transport costs.
Use of recycled product (compost "Minami-No-Hikari")
- Because it is made from food waste, it is a safe and nature-friendly organic compost.
- Fully meets the quality standards of the NPO Japan Bark Compost Association, surpassing common composts. It can be used in various situations from full-scale agriculture to landscaping/greening projects and kitchen gardens.
- The performance of our recycled products has been evaluated, and our product delivery record is improving.
*This business is conducted by Miki Biotech Co., Ltd. (our wholly owned consolidated subsidiary)
Zero Emission Promotion Activities
We define zero emissions as the reduction of the final disposal volume of construction by-products to as close to zero as possible, and have been promoting this initiative company-wide since FY 3/2007. POC's overall recycle rate of construction waste for FY 3/24 was 99.6% (96.0% for the previous year), and the final disposal rate was 0.4% (4.0% for the previous year). The basic unit of final disposal of waste per construction volume was 437kg/100 million yen (FY 3/23 result: 6,537kg/100 million yen). In FY 3/25, we will strive to improve the recycling rate and make systematic efforts to achieve zero final disposal of waste.
Basic Policy for Promoting Zero Emission
Promote the 3R activities and strive to achieve zero final disposal volume in construction waste
Priority items
- Reduction of construction waste generation
- Ensuring sorted waste collection and waste recycling in line with regional characteristics
- Conducting educational and awareness-raising activities (sharing awareness)
Indicators and Targets
Amount of Construction Waste
Total emissions in FY 3/24 decreased by 72.1 thousand tons from the previous year to 498.9 thousand tons. The decrease was attributed to a significant fall in the amount of construction sludge from both civil engineering and building construction projects.
Recycling Rate
In FY 3/24, the recycling rate for all items increased by 8.6% to 99.2% for civil engineering projects and increased by 0.4% to 100% for building construction projects, resulting in overall rate of 99.6%, up 3.6% from FY 3/23.
Waste emissions per unit of production decreased 34.3t/100 million yen to 118.1t/100 million yen. Its breakdown showed the same decreasing trend for both of the business units, with a decrease of 41.9t/100 million yen to 121.1t/100 million yen for civil engineering projects, and a decrease of 26.4t/100 million yen to 114.8t/100 million yen for building construction projects.
The final disposal rate was 0.4% (FY 3/23 result: 4.0%), and the basic unit of final waste disposal per construction volume was 437kg/100 million yen (FY 3/23 result: 6,537kg/100 million yen).
Utilization rate of recycled soil and sand / Effective utilization rate of construction generated soil
The effective utilization rate of recycled sediment resources in FY 3/24 increased to 90.9% from 71.6% in FY 3/23. The reason for this increase was the rise of effective utilization rate for both civil engineering projects and building construction projects, from 67.8% and 96.4% in FY 3/23 to 90.3% and 98.2% in FY 3/24, respectively. In addition, the company-wide effective utilization rate of construction soil generated was 92.8% (FY 3/23 result: 92.6%), an increase from the previous fiscal year.
Promotion of Energy and Resource Saving in Offices
As part of our efforts to conserve resources and energy in our offices, we are working to reduce the amount of copier paper used, conduct green procurement, reduce electricity consumption, and sort and collect waste.
Reduction in Consumption of Copier Paper
We are thoroughly implementing activities to reduce copy paper usage through double-sided copying, one-sheet copying, use of the reverse side, use of electronic media, use of recycled paper, and inventory control of purchased quantities.
Green Purchases
As part of our office environmental activities, we manage the ratio of green product purchases for office supplies. We will continue to promote green purchasing.
Reduction of Electricity Use
We are working to reduce electricity consumption by implementing power-saving measures such as turning off lights during lunch breaks, turning off partial lights when leaving the office, setting air conditioner temperatures and operating air conditioners in limited areas after hours, and using electric fans.
Separate Collection of Waste
Separate trash boxes are placed on each floor of the office for separate collection.
