Vetiver Grass For Landfill Leachate Seep Control

Did you know vetiver grass can be used to prevent or repair leachate seep breakouts on a landfill slope? A leachate seep occurs when the contaminated liquid in a landfill comes out where it isn’t supposed to, potentially contaminating surface water and groundwater. If not properly pumped, leachate can build up in the waste mass and force itself out wherever it finds a crack or the path of least resistance.

Modern landfills are designed with leachate collection systems and synthetic liners that catch any liquid in the waste mass and directs it to a containment area like a lined pond or tank where it is then properly treated or disposed of in a way protective of public health and the environment. However, there are many landfills and old dumps throughout the world that are not designed or managed in today’s engineering standards, and leachate seeps can be a serious problem for the local communities. Even modern landfills with liners can experience leachate seep breakouts, so it is a common situation that requires attention.

Ways to repair a seep can include spreading dirt or compacted clay and adding grass seed. This may work, but leachate can break out again in that spot or somewhere else nearby, especially if it continues to build up in the waste or not properly extracted in a collection system.

A natural solution is using the vetiver system. With its impressive abilities to uptake high volumes of water and to stabilize and/or use contaminants, vetiver grass can be a perfect low-cost option. Not only will it soak up any excess liquid that comes out of the landfill, its roots will also help stabilize the slope.

Recently, Leachate Management Specialists successfully repaired a leachate seep at a landfill in the Gulf Coast of the US using vetiver grass. A leachate seep had developed, so the landfill owners asked us if we could offer a natural long-term solution to repair it.  We planted vetiver over the seep breakout at the landfill and monitored the progress. Within a few short months, the surface of the ground is now dry and the plants are growing well. We will continue to evaluate the project, but we are quite happy with its performance so far!

It is important to remember that a seep repair using vetiver should be carefully considered and designed because, although more tolerant than many other plants, vetiver is not omnipotent, and highly contaminated leachate (or other environmental conditions) can kill it, especially young plants. And if a project like that fails the first time, you might not be allowed to try vetiver again there or elsewhere.

~ ~ ~ ~

We specialize in providing nature-based systems for landfill leachate and industrial wastewater in the US and use vetiver grass wherever it can grow. We typically design and install systems that take leachate that is already pumped out of a landfill and distribute it to fields of either vetiver grass or trees on top of the landfill. The plants consume the liquid through evapotranspiration and use the contaminants to fuel fast growth.

  • Hi Eric, I can’t reply directly to your comment. Thanks for the answers. Not that I would ever be involved in leachate disposal, it’s just nice to know the reasoning of an application. One could almost consider the planting here like an almost literal band-aid in healing and drying an unwanted wound.

    The open pattern of Vetiver plants chosen, is that because it increases transpiration and growth for each clump? Where I live, one could not use that pattern without extensive maintenance as the surrounding pasture would grow over and cover the Vetiver quickly and I’m surprised that hillside is only mown twice a year. I would probably plant close hedges to reduce the weed growth and other maintenance needs but you are the expert on this particular application so I’m interested in the particulars.

  • Hi Eric, Nice write-up. If that’s functioning like a spring, how’d you prep that and are they wheel tracks through the wet area? How is it maintained now, the widths look narrow for what I assume is a tractor? If I was to walk between the Vetiver, is the ground still wet and if anything, the Vetiver now functions as a fence for mechanised equipment to keep off?

    • Thanks, Evan. I think the seep is seasonal depending on rainfall and leachate extraction. We added some dirt to the area and graded it, then placed a mix of mature vetiver plants and bare-root slips. The wheel tracks were from routine mowing of the landfill cap that occurs only a couple times a year. The mower can drive around it easy enough, then once a year, we can use a raised bushhog to mow the old growth. The ground was dry when I was there last.

  • A very useful post. It should be noted that in many parts of the world household septic systems suffer from somewhat similar situations where effluent leaks and becomes surface flows polluting down slope land and water. Vetiver can be usefully applied at very little cost to dry up those leaks.