Tour Time: the Landfill

The tour continues, this time we are off to the landfill!

Do you have a preconceived notion of what a landfill looks like? I know that I sure did and it was nothing like what I saw when I got to Resource Recovery. I will never forget driving to my first meeting here, with Krystal, to discuss me coming here for my internship. I thought to myself, "Where is the landfill? All I see is green grass hills!" I don't exactly know what I was looking for when I thought of a landfill, I guess I thought that I would see a lot more trash, however, it certainly was not what I saw driving down Shun Pike.

Those grassy hills that I saw on my first drive down here are in fact the first three phases of the landfill. So now I'll try to break down what happens at the landfill:

The landfill at RIRRC is the state's central landfill (the only active landfill aside for the active landfill in Tiverton, which will most likely be closed within the next year). Just about every city/town had their own dump for trash. These have all since been capped (with the exception of Tiverton) and built around. Meaning, most Department of Public Works (DPW) yards and buildings are placed where their former landfills existed.

The landfill is broken down into 6 phases:

In the early 1980's the RI Solid Waste Management Corporation (RIRRC's former title) bought the Silvestri landfill in Johnston, RI. This was an unlined landfill. It has been capped and closed since 1993.This is the first phase of the five phases of the landfill.

The second phase of the landfill began with the closure of the first phase in 1993. With this new phase, we became a sanitary landfill. Meaning that the contents of the landfill are sealed in and are not allowed to interact with the soil, avoiding contamination.

In 1997, RIRRC moved onto phase three of the landfill.

The third phase only lasted a short while, when the fourth phase began in 1999.

*Phases 1-4 have all been capped.

In 2004 phase five began. This phase is still active.

Finally, the sixth and final phase of the landfill began in 2015 and will end the life of Rhode Island's central landfill, which is projected to close in 2034. "Eventually this expansion will require the removal of our tipping facility, removal of the old power plant, relocation of the compost area, removal of the administrative building, relocation of the small vehicle area, and relocation of the mixed glass cleaning and sorting operation."

Each of these phases (aside from the first) is lined at first to avoid soil/water contamination and second it is sealed at the top once it has settled. these linings are made up of two parts: clay/sand and plastic.Once capped, either grass is planted or turf is used to cover the linings.

If you couldn't already tell, the landfill is an engineering marvel. The engineers are always figuring out the best place for the trash to be compacted to use as little space as possible, to keep the life of the landfill as long as possible. They do this with GPS equipped trucks equipment, so they know exactly how much trash is placed in any given area. They are also moving the roads that allow for the workers to get around up on the hill based on the structure.

Each day the compacted trash must be covered. It is primarily covered with gravel and Posi-shell. This is a layer (similar to stucco) that gets sprayed on so that animals cannot dig in the garbage, it also prevents any loose trash to be covered so that it is not able to fly away. There was a law put into place that banned Resource Recovery from used the glass recycled from the MRF as cover. One reason for this was that it was thought that it did not do a good enough job at sealing in the odor, but as of a recent legislative session, the state Senate passed a law that allows glass to be mixed into the cover material, stretching what is bought for material. This will save RIRRC money, using an item that is allowed in the mixed recycling stream, but does not have a market to be sold to.

Although it is a sanitary landfill, there is contaminated water, called leachate that is collected by pipes and send to the two large holding tanks before it is send to the pre-treatment plant. There is 230,000 gallons of waste water produced by the landfill daily. Each hold tank can hold up to 750,000 gallons each and the pre-treatment can treat a maximum daily flow of 650,000 gallons of wastewater per day.

Aside of the leachate that is collected underground, the runoff water from the landfill is collected in retaining ponds. This water is not contaminated like the leachate, the ponds are in place for more a safety precaution.

There is more than just water being collected at RIRRC. There is a system of pipes and meters that capture methane gas. This gas is used at Broadrock Renewable Energy (which is located right across the street from RIRRC) to provide energy for over 28,000 homes!

I could go on and on for days about the details of the landfill, but I think that I have hit the highlights. As for the MRF tour, there is an amazing virtual tour and lots more information over on the RIRRC website, click here for more information!

Shown below are some of my personal photos from my tour of the landfill: