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Cleaning the ocean plastics and reusing the plastic waste as a source of energy at wastewater and water treatment plants in coastal areas.



Our proposal is to offer wastewater treatment utilities a gasification technology to incorporate within their wastewater treatment process, in addition to a waste collection service that will provide ocean plastics as a source of energy at these facilities. The technology would allow a wastewater treatment plant to turn ocean plastic waste into synthetic gas, which can then be used to power the wastewater treatment process at the utility, reducing its reliance on fossil fuels. We would work with established local nonprofits to collect the plastic waste and sell it to the wastewater utility. We would realize a profit through the sale of the technology and the plastic supplying service, while the wastewater utility would recover significant cost savings over  time. This is possible since the energy generated would be worth more than the plastics cost. This financially sustainable system would ensure that there is always an incentive for collecting plastic waste in coastal areas.


The proposed idea will help clean plastics currently polluting the ocean and coastlines and will reuse them as an energy source at wastewater treatment plants. Plastic pollution has infiltrated our food supply chain and our recreational areas and is bound to tighten its hold on our ecosystem. Harvesting this plastic waste and reusing it as an energy source to clean human waste will create a cradle-to-cradle solution while helping wastewater utilities run a more lean and profitable operation.

Is this proposal for a practice or a project?


What actions do you propose?

New gasification technologies convert materials to synthetic gas (syngas) using lower quality feedstocks. Low-grade plastics present an opportunity since gasification can use recovered ocean plastics for conversion into synthetic fuels. The conversion of plastics to syngas could be used in wastewater treatment plants for electricity or steam, since syngas is a combustible fuel that can replace natural gas with minimal pretreatment. This consistent stream of energy will reduce the facilities’ reliance on the power grid and increase its ability to remain functional during extreme weather events, which typically suspend the supply of power.

This project seeks to further the advancement of such technology and put it into practice: in essence, it will streamline a process for collection and delivery of recovered ocean plastic to the gasification reactors installed at wastewater treatment plants, thus providing a cleaner supply of energy to treat wastewater - using waste to clean waste. This is a long-lasting solution to clean our oceans, divert plastic waste from landfills, increase the sustainability of the wastewater sector, and build more energy-secure communities.


Who will take these actions?

The team proposing this idea, Global Water Girls, will be the company managing the project and coordinating with the project partners to implement the project. The project partners are the following: Sustainable Coastlines Hawaii, Biomass Energy Systems, Inc. (BESI), and the City of Honolulu. The core GWG team is made up of four people, all of which have a dedication to the water sector. Fidan Karimova, Founder and CEO, will manage the overall operations and resources for GWG on a day-to-day basis. Anjali Gupta, Co-Founder and CTO, will focus on the scientific and technical operations and oversee technical development for GWG. Katy Lackey, GWG’s Research Manager & Outreach Coordinator, will conduct outreach and community/stakeholder involvement, as well as survey background literature, interviews, write briefs and draft reports. Grace Richardson, GWG’s Applications Engineer, will coordinate on the implementation of the technology and on issues of climate change adaptation and energy recovery. Also involved in GWG is Livia Ehardt, GWG’s CFO, who will oversee GWG’s budget, process expenditures, handle expense reimbursements to partners, and prepare and manage the company’s financial records. Other key personnel not within GWG include Renee Comly, CEO of BESI, technology provider, who will lead the technology installation and management process, and Kahi Pacarro, the Executive Director at Sustainable Coastlines Hawaii, who will supply the ocean plastic from conducting coastal clean-ups.


After a pilot of the technology and the proof that it works well with the use of 100% plastic feedstock, GWG will then pilot or fully install the technology at a wastewater treatment plant in another coastal area battling plastic pollution. For the projects following the Hawaii pilot, GWG will sign a contract with: Davi Victral, to conduct the next pilot/full scale installation in Brazil, (Consulting Feedback); Jose Fernando Perusquia, to pilot the technology in Mexico; Ulrik Sludekilde, to research potential uses for the ash end-product of the plastic gasification process.

Where will these actions be taken?

The smaller, preliminary pilot will take place in Chicago, where the BESI technology is currently located. This is where we will test the feasibility and results of using 100% plastic feedstock for gasification. The full pilot will then take place in Hawaii, since there are already interested partners on the ground such as BESI, and the city of Honolulu Wastewater Treatment Plant. As such, Hawaii serves as the best test location for launching this project.


Pending successful pilot results, the solution would then be tested in Brazil and Mexico respectively, as the two countries are combating plastic pollution and GWG has established contacts at wastewater treatment plants to partner with for testing the solution.

After the Americas, where the idea will be tested and fully installed, the next two locations will be in Asia, specifically in China and India. These two countries are the biggest emitters of plastic waste that eventually reside in our oceans due to ocean currents. Scaling the technology to take in higher amount of plastic feedstock at wastewater treatment plants in China and India would help to alleviate a primary cause of plastic waste plaguing our ocean ecosystem.

In addition, specify the country or countries where these actions will be taken.

United States

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What impact will these actions have on greenhouse gas emissions and/or adapting to climate change?

If the pilot is successful in Hawaii, we will gradually begin to see less of a fossil fuel dependence from the City of Honolulu Wastewater Treatment Plants. To estimate the potential impact of the pilot project on greenhouse gas emissions, we assume that that we can offset 50% of total purchased electricity usage at one of Honolulu’s treatment facilities, the Kailua plant, a 15 MGD design flow facility on the island of Oahu over the period of the next 15 years. This facility uses approximately 7.8 million kWh/year. In general, we assume that 7.03x10^-4 metric tons of CO2 are released per kWh (based on EPA estimates). By generating 50% of the electricity demand onsite, and assuming that this offsets 90% of the greenhouse gas emissions due to that energy use (to account for potentially increased truck traffic to deliver plastic waste feedstock), roughly 2,500 metric tons of CO2 will be reduced per year. Over a period of 15 years, this amounts to 37,000 tons of CO2 reduced from overall emissions. However, should the pilot prove successful, it is assumed that the operations would be scaled to offset electricity usage across Oahu. Assuming the electricity demand per MGD treated is the same across all 9 of Honolulu’s treatment plants which, combined, treat approximately 112 MGD, total electricity consumption for Honolulu’s wastewater treatment is around 73 million kWh/year. By offsetting this electricity consumption by 50% over 15 years, we see a total reduction of 350,000 tons of CO2 emissions.


Further, beyond reducing greenhouse gas emissions, this project will reduce the coastal wastewater treatment plant’s reliance on fossil fuels, which are the source for around 75% of Hawaii’s electricity. With critical infrastructure such as wastewater treatment, onsite generation of electricity will greatly reduce reliance on the grid, and will allow the facilities to adapt to the possibility of insecure sources of power during extreme weather events and other climate change related disasters that threaten access to electricity. By offsetting such a large percentage of costs, onsite generation will also greatly contribute to the financial sustainability of the wastewater treatment operations. Since many of Honolulu’s treatment facilities currently use cogeneration with anaerobic digester gas produced onsite, this project may even allow these facilities to approach net-zero electricity consumption. The data gathered from this pilot project will allow estimation of the feasibility of such a venture.

What are other key benefits?

Currently, the gasification technology is being used on an air force base and in remote locations around the world to clean general waste (i.e. waste found in trash and food discards, which includes plastics). To date there have been no wastewater treatment plants that have utilized this type of gasification technology, with the feedstock being 100% plastic waste. The strategy hence lies in proving through this pilot that wastewater utilities can save considerable costs through this technology, and would therefore be willing to be part of our waste harvesting service. The end goal is to help use waste to clean waste and get people closer to living in a cradle-to-cradle system.

The start of the project will be at wastewater treatment plants, to get over the initial hump of encouraging gasification of the biosolids. Once that concern is addressed, the type of solution could be utilized at water plants, industrial facilities, municipalities, breweries, etc.

Furthermore, in the process of gasification an ash is produced. That ash can be utilized on road pavings and other types of architectural constructions. The end result could be a zero waste system that not only provides a source of cheaper energy to power treatment plants, but also provides an ancillary product that can be put to other beneficial uses.

The major goal that this proposal can help meet is helping committed countries achieve the UN Sustainable Development (SDG) goal 6 - ensuring availability and sustainable management of water and sanitation for all. The target of SDG goal 6 is to achieve universal and equitable access to safe and affordable drinking water for all by 2030. Although this proposal will not accomplish the goal 100%, it will help us make a significant leap towards accomplishing that goal.


What are the proposal’s projected costs?

We will first need to test this technology at a wastewater treatment plant in a form of a pilot test. During that pilot process we will also record and report on the pilot results, in order to have the information to pitch to other wastewater utilities. In order to conduct the pilot we would need $2 million, which is broken down as follows: technology - $1,500,000, wastewater treatment plant - labor costs of the utility engineers; research report (data and analysis of the pilot and information sharing with other interested utilities) - $400,000; core team to implement the pilot from start to finish - $100,000.


Reducing the plastic pollution in the ocean is a challenging and daunting task. However, we believe our project will be the catalyst for a larger movement towards cleaning the oceans while reducing reliance on fossil fuels. In the US alone, 3-4% of the nation’s electricity is used for cleaning water.


A. In the short-term, our proposal will help to increase the awareness of the sheer amount of plastic in the oceans and on our coastlines. A successful pilot in Hawaii will prove 37,000 tons of CO2 reduced from overall emissions. Additionally, it is assumed that the operations would be scaled to offset electricity usage across Oahu. Estimating that the total electricity consumption for all 9 Honolulu’s WWTPs is a combined 73 million kWh/year, we will see a total reduction of 350,000 tons of CO2 emissions over 15 years.


B. In the medium term, our proposal will have been established at 4 other wastewater treatment plants around coastal areas of the world, in addition to continuing operations at the City of Honolulu (full disclosure: MOUs have not yet been established with these utilities, these are being used for estimation purposes). The overall impact of our project in the medium term will be 3.5M (million) tons of carbon emissions reduced from the combined 13 wastewater treatment plants (9 WWTPs in Honolulu and 4 international WWTPs), see below for the breakdown. The following estimates were provided by the EPA for determining power used at conventional wastewater treatment plants: “...1004 kwh/day at 1 mgd, 8128 kwh/day at 10 mgd, and 75,864 kwh/day at 100 mgd size.”

  • Sanepar, Brazil: The major WWTP in Sanepar treats 132 MGD and uses roughly 105,000 kWh/day, which will amount amount to roughly 424,345 tons of CO2  emissions reduced over the span of 35 years.


  • Atontonilco, Mexico: The Atontonilco WWTP treats 525 MGD and uses roughly 153 million kWh/year. Implementing our project would reduce approximately 678,950 tons of CO2 emissions reduced over 35 years.


  • Hong Kong, China: The Stonecutter’s Island Sewage Treatment Plant in Hong Kong treats 647 MGD and uses approximately 188 million kWh/year. We estimate 832,525 tons of CO2 emissions reduced over 35 years.


  • Chennai, India: The Chennai Metropolitan Water Supply & Sewerage WWTP treats 73 MGD and utilizes about 21.9 million kWh/year. We estimate 242,480 tons of CO2 emissions reduced over 35 years.


  • City of Honolulu, Hawaii:

After 50 years, the Oahu WWTP will reduce 125,000 tons of CO2. For all 9 WWTPs in Hawaii we estimate a combined, total reduction of 1.2 million tons of CO2 emissions.

C. In the long term, assuming that all 13 WWTPs are operating, we will reduce 8.5 million tons of CO2 emissions overall by the end of year 100. We can expect 2.3M tons of CO2 reduced from the Hawaii pilot plant, 1.2M tons of CO2 reduced from the Brazil WWTP, 1.9M tons of CO2 reduced from the Mexico WWTP, 2.4M tons of CO2 reduced from the Hong Kong WWTP, and 0.7M tons of CO2 from the Chennai WWTP.

About the author(s)

Anjali has a strong background in Environmental Engineering with a concentration in Water Resources, and GIS capabilities. As a former contractor for the EPA, she wrote specific Policy Guidance for Facilities Planning Management, Water Conservation, and Cost and Effectiveness. Anjali helped design a Waste Vegetable Oil System, using waste vegetable oil from restaurants to preheat the water needed for a power plant.

Fidan has over 7 years of experience in working with utilities and organizations to transition from innovative ideas to implementation practices. She has previously worked with entrepreneurs from over 86 countries. Fidan created TheWaterTracker, a mobile app that measures water use and helps users understand differences in the water consumption of their daily activities and practices.

Katy has over 9 years of experience in research, community advocacy, and program development. This work includes working with an environmental audit team to conduct a water quality assessment for Costa Rica, and exploring the evolution of stormwater management through a GIS mapping lab in Colombia. Katy serves on the Executive Board of the Women's Aquatic Network (WAN) in Washington, DC.

Grace has over 7 years experience in implementing innovative technologies in water and wastewater utilities. She has led demonstrations of technology to improve drinking water quality and to restore polluted bodies of water. She also has experience in energy management at water resource recovery facilities. She is passionate about developing solutions to provide safe and sustainable water resources to communities throughout the world.

Livia has over 7 years of experience working in the accounting industry. She has migrated to the corporate world where she provides technical accounting and transaction support for a large aerospace & defense public company. As part of her undergraduate studies, Livia also pursued a degree in biology to satisfy her curiosity for science and the environment.

Related Proposals

Energy Supply - Our “Oceans Plastic to Energy” proposal uses new gasification technology to ultimately reduce the dependence of coastal wastewater treatment plants on fossil fuels.

Adaptation - Our “Oceans Plastic to Energy” proposal uses new gasification technology to reuses plastic waste and to decrease reliance on burning fossil fuels, which demonstrates that there are advanced technologies available to help us adapt to our changing climate.


EPA’s Greenhouse Gas Equivalencies Calculator:

City of Honolulu, Comprehensive Annual Financial Report:

Energy Assessment Report for County of Honolulu, Kailua Wastewater Treatment Plant:


Sanepar WWTP:


EPA: Electrical Power Consumption for Municipal Wastewater Treatment