Understanding, Managing, and Preventing Clogging of Landfill Systems with Black Sticky Material (aka “Black Goo”)

Investigator: University of Wisconsin-Madison

Start Date:
September 2021

Award Amount:

Black solids have been accumulating in recent years within waste and in leachate and gas collection systems, causing clogging that adversely affects management and extraction of leachate and gas. These solids consist of a sticky organic material that also contains a variety of other solids or precipitates entrained within the matrix. Anecdotally referred to as “black goo,” this sticky material fills pores within waste, leachate collection layers and sumps, and the stone and screens for gas and dual-phase extraction wells. Black goo also accumulates in pumps and other appurtenances. Clogging caused by black goo affects gas and leachate management adversely, requiring costly and frequent maintenance to ensure systems operate properly. Developing means to prevent black goo from forming and accumulating within landfills is important for the industry. The proposed study focuses on understanding black goo, developing methods to prevent black goo from forming in landfills, and finding means to remedy landfill systems clogged with black goo.

The study has the following objectives:

• Understand waste streams containing materials comprising the black goo, how they contribute to formation of black goo, and under which conditions.

• Understand how black goo forms (or transforms) in a landfill as well conditions affecting composition and rheology, specifically viscosity and propensity to bind to landfill materials.

• Understand how black goo clogs pores in waste, in leachate collection systems, and gas and leachate extraction wells.

• Use findings from above to develop methods to prevent black goo from forming in landfill environments and to identify optimal methods to remedy clogging by sticky material.