Spring is coming. Get ready to remove your lagoon’s sludge blanket

DATE POSTED: January 29, 2020


It won’t be long before spring weather arrives and wastewater lagoons begin to thaw and return to more efficient operation. But as this happens, non-aerated lagoons can experience benthal feedback—a process where the turbulence of the warming water stirs up the sludge blanket and releases hydrogen sulfide gas along with nutrients that have accumulated in the settled sludge. 

The result is not only wafting odours, but also potentially high concentrations of TSS, BOD, phosphorus and ammonia in treated effluent. In some cases, the concentrations of some wastewater constituents can be higher in the treated effluent than the influent.

An excessively thick sludge blanket can often be the cause of these symptoms. Too much sludge also reduces lagoon capacity, retention time and can change the flow path of the wastewater. 

Removing some, or all, of the sludge blanket can quickly restore lagoon capacity and eliminate performance issues. In some cases, the installation of baffles, aeration and/or fixed-film biological treatment can also provide a significant, cost-effective improvement to lagoon performance.

Map the blanket to fully understand the problem

Creating a sludge map is an important first step to measure the thickness of the sludge blanket and how it’s distributed throughout the lagoon cell. Once the measurements are complete, Bishop Water can discuss important sludge management considerations and actions including: 

  • Current lagoon capacity vs. design capacity
  • Depth and distribution of sludge
  • Location and volume of recommended sludge removal
  • Budget and long-term planning for sludge removal

Bishop Water Technologies can provide comprehensive services to measure, plan, remove and dewater sludge from wastewater treatment lagoons of all sizes. Our advanced hydraulic dredge enables lagoon cleanout to occur while the facility remains in operation and the Bishop Solids Management Solution—using Geotube® dewatering containers—dramatically reduces the cost of sludge disposal and truck traffic.

Contact us to discuss your lagoon’s sludge blanket and a sludge management plan. 

Learn more about the Bishop Solids Management Solution

Are you on the right path for lagoon sludge management? A sludge map can help.

DATE POSTED: November 27, 2019


How much sludge is in your treatment lagoon? Is it half full or half empty? Either way, digging up the dirt on your sludge can be a huge asset for optimizing the lagoon’s performance and reducing operating costs.

Creating a sludge map is an important first step to improving lagoon management and can reveal critical information about the volume of sludge and how it’s distributed throughout the treatment cells.

Our sludge mapping team often finds that sludge depth is significantly different than what operators expected and that it’s unevenly distributed in lagoon cells. These factors alone can cause a number of problems in lagoon operation such as insufficient treatment capacity and retention time, flow impediment, short circuiting, and inadequate removal of BOD, TSS and/or ammonia. 

But once the information is in hand, operators and utilities managers can benchmark the current sludge situation and make informed decisions on a number of sludge management actions including: 

  • Current and required lagoon capacity;
  • How much sludge to remove and from which areas of the lagoon;
  • How often sludge should be removed;
  • Budget planning for removal.

Depending on the results, lagoon operators may decide to cleanout the entire lagoon, or remove sludge only from areas of concern. 

Bishop Water Technologies and its business partner, Geo-Dredging and Dewatering Solutions can provide comprehensive services to measure, plan, remove and dewater sludge from wastewater treatment lagoons of all sizes. Our advanced hydraulic dredge enables lagoon cleanout to occur while the facility remains in operation and our onsite dewatering capabilities—using Geotube® containers—dramatically reduces the cost of sludge disposal and truck traffic.  

Our affordable sludge mapping services can often be completed in a day or two and can include a sludge profile that will show the composition of the sludge, identify contaminants and the dewatering properties of the sludge.

Contact us to discuss a sludge survey for your wastewater lagoon.

Learn more about our sludge mapping and sludge profiling services.