DCDigesterCheckKnow before you clean.

Digesters We Assess

Different feedstocks.
The same expensive question.

Should this digester be considered for a cleanout?

Canadian anaerobic digestion facilities

Agriculture & manure

Dairy and livestock digesters, including facilities where sand, grit or bedding may contribute to accumulation.

Food waste

Digesters receiving food-processing residuals, commercial food waste and other organic feedstocks.

SSO & organics

Facilities receiving source-separated organics and mixed organic streams where contaminants may be present.

RNG & biogas / CHP

Digesters supporting renewable natural gas, biogas utilization and combined heat and power facilities.

Wastewater

Anaerobic digestion assets at wastewater treatment facilities where solids and grit accumulation may affect usable volume.

Common configurations

Mixed plug-flow / DVO-type systems, CSTR and other anaerobic digester configurations, subject to available information and access.

Common digester configurations

Different systems. Different accumulation patterns.

Covered plug-flow anaerobic digester at an agricultural siteAGRICULTURAL PLUG-FLOW EXAMPLE

Covered plug-flow / DVO-type

Long, covered digester configurations commonly used in agricultural applications. Feedstock characteristics, bedding and grit can influence where material settles along the flow path.

Covered anaerobic lagoon digesterCOVERED LAGOON EXAMPLE

Covered anaerobic lagoons

Large-volume covered basins can accumulate settled material over time. Available depth, solids distribution and operating history are important context when considering usable capacity.

Complete-mix anaerobic digester tanksCOMPLETE-MIX TANK EXAMPLE

CSTR / mixed tanks

Continuously mixed tank systems rely on effective mixing and usable volume. Changes in solids behavior, mixing or pumping can be useful indicators for further investigation.

Reference photographs: U.S. EPA AgSTAR. “DVO-type” describes a general covered plug-flow style and does not imply affiliation with or authorization by any manufacturer. Images are examples of digester configurations, not DigesterCheck client sites.

HRT & usable volume

Why retention time matters.

Hydraulic Retention Time (HRT) is the average time material remains in the digester. In simplified terms:

Usable digester volume÷Daily influent flow=Approx. HRT

If settled material occupies part of the intended working volume, the effective usable volume—and therefore the effective retention time—may be lower than the original design basis. HRT alone does not prove a cleanout is required, but it is one useful piece of the assessment.

USABLE VOLUME
ACCUMULATED SOLIDSPotential lost volume

Service area

DigesterCheck is Canada-focused, with initial emphasis on Ontario, Alberta, British Columbia and Québec.

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