Plastics in erosion prevention & sediment control practices. Has the Band-Aid become worse than the wound?

Peter Leete, MnDNR
Topic Area
Emerging Issues and New Directions in Transportation Ecology

Proliferation of plastics is everywhere and has become a global pollution issue. Has anyone taken the time to evaluate just how much plastic our industry is contributing due to erosion prevention and sediment control products? The National Pollutant Discharge Elimination System (NPDES) permit program does not specify that erosion prevention or sediment containment Best Management Practices (BMPs) contain plastic. Though that is a direction the industry has gone. Plastics are now common components of products used temporarily for perimeter control (silt fence & logs/rolls), rolled products (erosion control blanket), in-water containment (silt curtain), Hydromulch (fibers may be synthetic), and slope stabilization methods (geotextile fabric and turf reinforcement mats). But what happens to the plastic in these products? Are they removed when their need has past? Can they be removed? Some may be intended to be permanent, but do they stay in place? Typically, erosion prevention and sediment control products are installed for a temporary need, yet often are left permanently on the ground. Their need is for weeks to months. Yet their plastic components may last for decades or centuries. Is this adding to the buildup of plastic pollutants in the local and global environment?

Sediment is commonly considered a pollutant. Yet it is also a very important component of the natural geomorphic process of our streams and rivers. Deciphering which is what, and when, is a dilemma for project designers and regulators. Determining whether the use of plastic is an essential component of the project, or a contributing pollutant is a difficult task. It is a similar dilemma to deciding whether a piece of art is pretty or ugly. Plastic is not a natural component of stream ecology at any level. Though we are commonly accepting and/or requiring the addition of plastics to the environment in order to prevent sediment from being added to it. Have we reached a point of the Band-Aid being worse than the wound?

This presentation does not have answers, only examples and questions.

Abstract Keywords
Microplastic
NPDES
Erosion Control