Thursday, October 15, 2015

Come See PW Landfill Transforming to an Eco-Park

On Saturday, October 17, 2015 from 10 am to 2 pm there will be a free event at the Prince William County Landfill, with music and Landfill Tours throughout the day that would allow you to see the changes that are transforming the Landfill to an Eco-Park. An Eco-Park is a place used to demonstrate sustainability and reuse. Eco parks have been developed on former industrial sites and in the past decade as part of sustainable industrial development around the world. Here in Prince William County the landfill is has been undergoing a transformation to an eco-park; an ecologically sustainable operation producing green energy, recovering materials and providing a unique location for education and research.

Prince William Landfill is right off of Dumfries Road in Manassas, VA and has operated at this location since 1972 when it was merely the county dump. Today the landfill encompasses 1,000 acres, receives about 1,000 tons/day of household trash, and has extensive environmental controls. The oldest section of the landfill contains 57 acres that were closed in 1991 when the state law that regulates landfills (HB 1205) went into effect. That area is currently used for little league fields and has been undergoing retrofit with liners and leachate and landfill gas collection systems to protect the environment in an ongoing effort to manage the mistakes of the past. The newer section of the landfill was designed to comply within modern environmental regulations and sustainable practices.

Today Prince William County Landfill is engineered and built as a series of cells. The cells include liners of plastic membranes and watertight geo-synthetic clay liner fabric on the bottom of the cells along with a leachate collection system. At the end of each day, earth covers the trash deposited in the cell, to keep animals away, improve aesthetics- cut down on the smell. When a cell if full it is capped to prevent (or at least limit) the rain that percolates through the landfill and covered in soil. Most recently, the landfill capped the Phase I section and opened up a newly lined cell in the Phase II area.

The PW Landfill has a series of groundwater monitoring wells that are observed and/or sampled quarterly to ensure that groundwater is not impacted or any impact is contained and 100 landfill gas extraction wells. Landfill gas is generated during the natural process of bacterial decomposition of organic material contained in the trash buried in the landfill. Landfill gas is approximately forty to sixty percent methane, with the remainder being mostly carbon dioxide. Landfill gas also contains varying amounts of nitrogen, oxygen, water vapor, sulfur, and other contaminants. The gases produced within the landfill are either collected and flared off or used to produce heat and electricity. The landfill gas cannot be allowed to build up in the landfill because of the explosive potential. PW Landfill has operated for almost 40 years and has more than 7 million tons of trash buried at the landfill. That trash currently generates in excess of 2,700 standard cubic feet per minute of landfill gas up from 1,600 standard cubic feet a minute in 1999.

In the late 1990’s NEO Prince William (Fortistar) installed a landfill gas collection system and a 1.9 Mega Watt generator tied into the electrical grid. This first stage of the renewable energy development program became operational in November 1998. The landfill electrical generation plant was expanded in November 2013. The facility, still operated by Fortistar, now generates a total of 6.7 MW of electricity. This is enough power for approximately 5,000 homes. NOVEC buys the renewable energy produced at the landfill and resells it to their customers.
Power Generation at Landfill 

Even with the expanded electrical generation there is still more than 200 standard cubic feet per minute of excess landfill gas available. So the county built a pipeline from the landfill to the county animal shelter on Bristow Road with connections to several buildings along the way to provide landfill gas to heat the Fleet Maintenance Building and provide fuel to the Animal Shelter incinerator (yeah, I know). A connection to the School bus garage was added in 2014. This allows the County Public Works Department to replace the propane formerly used with landfill gas which is a “Renewable Fuel Resource,” and reducing the energy footprint of our county. Now they are evaluating the potential to provide landfill gas for heating, cooling and power to the Kelly Leadership Center and other adjacent County and School buildings and using the landfill gas for vehicle fuel.

Last year the County Board of Supervisors approved an agreement with LEEP Holdings, LLC, of Vienna to begin a demonstration project to convert solid waste to reusable products at the landfill. LEEP was among three companies that submitted proposals to the County for this project. LEEP is currently demonstrating that they can process 250 tons a day of the 1,000 tons a day of garbage that the landfill takes in. Next year they are scheduled to process 300 tons of garbage a day by the third year, and reach the target 400 tons a day by the fourth year. Prince William County Solid Waste Division Chief Tom Smith said that during the demonstration, LEEP plans to show that it can successfully manage its waste conversion operation. “They are proposing to process and sort waste into different products, to pull the metals out for recycling, to turn the organics into a fuel pellet and to take plastic to make a lightweight aggregate for use in making lightweight concrete.” This project if successful will extend the life of the landfill.

In 2011 the County’s Solid Waste Facilities (Landfill and Balls Ford Road Composting facility) were designated as an Extraordinary Environmental Enterprise (E4) participant in the Virginia Environmental Excellence Program (VEEP). Prince William County Landfill is the only active landfill to have received this recognition. In 2012 the landfill was designated an “Audubon at Home” wildlife sanctuary. According to the Prince William Conservation Alliance, who organizes the annual Nokesville Christmas Bird Count, the Prince William County Landfill has the largest numbers of Bald Eagles in the county. On Christmas day 2012 the Birders counted 10 adults and 10 immature Bald Eagles, along with many gulls including 650 Ring-billed Gulls and three Great Black-backed Gulls. Prince William County’s Solid Waste Division was awarded the Virginia Governor’s Environmental Excellence Award in 2013 for its Sustainability Program.

Moving forward, the County has big plans for the landfill. They are looking to partner with private companies in developing solar power at landfill site. Even with the recent reduction in solar costs and the existing federal tax incentives cost is still an issue without state incentives. None the less, the county is exploring options with a private company and NOVEC to build a solar project in phases beginning with net metering to supply power to the buildings on site (1.3 MW) and potentially expand to other buildings. There is plenty of space on the landfill for solar panels, but without state incentives cost is still an issue. That could change with the new U.S. EPA mandated clean energy plan and the landfill will be ready to move forward.

Currently there are activities that occur on site at the Landfill. The Landfill buffer serves as a protected pollinator and wildlife habitat, and the on-site wetland and streams (which are carefully monitored for contamination) have a viewing platform. There are regular tours of the landfill buffer for environmental studies with local 4H Club and the Master Gardeners. There are also hiking trails, bird watching and nature exploration. There are also Landfill community events and tours. The Prince William Landfill would like to do more to expand programs on green building, energy efficiency, and sustainable living; the County hopes to develop and build an Education Center at the Landfill to encourage innovation and advance sustainable solutions to the environmental challenges we face.

1 comment:

  1. Have they looked at converting landfill Gas to Liquids?

    A company in Texas already builds the conversion plants

    "The GTL process utilizes the Fischer Tropsch process to convert gas to liquid fuels, a technology dating back to the 1920s ...
    This process involves three steps:
    1) Conversion of methane into carbon monoxide and hydrogen (syngas) through the reforming process.
    2) Reacting the syngas in the FT reactor to create what are known as long chain hydrocarbons.
    3) Conversion of these hydrocarbons into diesel, naptha, and ‘waxy bottoms,’ which may be further converted to additional diesel and naptha.