Lagoons vs Ponds

If you’re looking for standards from the EPA regarding groundwater and wastewater storage, you’ll need to determine whether you’re building a lagoon or a pond. Both are a type of in-ground storage area for water, but they vary slightly in their intended purpose and design. Some official documents still use the terms interchangeably, so verify the precise definition of lagoon or pond indicated in each standard before assuming it applies to your particular project.

Waste vs Fresh Water

In most materials, from sources like the Environmental Protection Agency (EPA), the term lagoon is used to refer to in-ground structures designed for wastewater. Lagoons are designed to hold groundwater that is contaminated in some way, even if those secondary ingredients are valuable on their own. In addition to wastewater, useful water in the midst of processing is generally held in a lagoon if it poses a contamination risk at all. Evaporation and processing ponds may be referred to as lagoons if they serve as storage areas as well. Manure sludge and acidic tailings may process into valuable fertilizer and metal ores respectively, but they’re all stored in lagoons due to the hazardous components. The term pond is much more flexible and is used often to refer to freshwater and wastewater storage structures.

Importance of a Liner

Since groundwater lagoons almost always contain some kind of wastewater, these structures generally require liners in all cases. Trying to use a naturally sealed lagoon will result in soil and water contamination due to seepage. Evaporation ponds and lagoons also require liners to maintain a steady rate of water loss. Finally, freshwater ponds can go without liners in some cases. However, this can result in the loss of valuable groundwater after it was pumped or reclaimed at a high energy cost. Liners make the most of every stored gallon by reducing seepage loss as much as possible.

Size and Shape

Lagoons and ponds can cover multiple acres of surface area and hold hundreds of thousands of gallons of water. The two terms don’t indicate any specific size or shape of the finished structure. Ponds, in general, are shallower than lakes. Lakes are deeper, and therefore have water that isn’t exposed to the light shining through the surface. This is known as an aphotic zone. Most lagoons and ponds alike used for groundwater storage don’t qualify as lakes, but some very large designs may take that form instead.

Once you’ve narrowed down the right terminology for your project, you’re ready to select a liner. You can always reach out to us here at BTL Liners for more advice tailored to your specifications.

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