A Covered Lagoon System is lagoon / pond that is covered with a not permeable cover. The lagoon is usually filled with manure. The cover traps gas produced during decomposition of the manure.
Covered lagoon biogas plants are used for liquid manure with less than 2% solids.
This type of digester is the least expensive compare to another types of digesters.
Requires large lagoon volume and a warm climate.