Biological Dredging of Wastewater Lagoons

The digestion of sludge by Arkea® in a lagoon not only extends the life of the lagoon operation, but also saves considerable operational costs normally associated with mechanical dredging.


Customer’s plant in the southeast processes up to 10,000 barrels of crude oil per day.

Approx 250 gpm of process water discharges from the plant site 24/7, passing through an onsite WWTP and through two lagoons, the south lagoon (primary settling), and the north lagoon (polishing/final effluent).

Customer Problems/Challenges

The south lagoon was approximately 85% full of sludge by volume, resulting in the loss of treatment and settling time, as well as increased risk of effluent permit violation in high flow events.

ArchaeaSolutions, Inc. Strategy

Lake DredgingArchaeaSolutions, Inc. used Arkea® bioaugmentation and process consulting to improve plant upstream efficiency and break down lagoon solids. Arkea® bioaugmentation included the addition of microbes, macronutrients, and micronutrients, as well as equipment utilization including Arkea® reactors and 2 aerators.


In approximately 10 months, the existing sludge solids in the south lagoon have been reduced by 57% as of the 01/14 survey date. Measurements were made at 9 different grid points. The average sludge blanket depth went from 42” to 18.2” inches. See measurement grids/charts and sludge measurement data below.

Long-term Arkea® treatment benefits to both lagoons are increased retention/treatment time, increased system freeboard, and improved ability to prevent/minimize carryover of sludge/solids during rain events.

ArchaeaSolutions, Inc. expects continued long-term progress and exceptional results with continued breakdown of incoming new process solids, as well as continued breakdown of remaining volatile solids in south and north lagoons.

South Lagoon Measurement Grid

South Lagoon Measurement Grid

Sludge Measurement (Inches) at Each Measurement Grid Point

March 4th 2013

June 12th 2013

January 10th 2014

Dredging Chart

Arkea® & Biological Dredging