Wastewater lagoons
Decades of loading had taken the lagoon to a measured 20.5 per cent solids, with a dredging quotation in hand and no budget line to meet it.
of organic solids digested
01The plant
A municipal lagoon holding about 99 million gallons.
02Before
Decades of loading had brought the accumulation to 20.5 per cent of the lagoon by volume. A dredging quotation was in hand at $2.5 million and there was no budget line to meet it.
03Treatment
Hydrated as a powder and applied around the lagoon perimeter over three months, July to October.
Every result in this library was measured at an operating plant treating with one of the formulations SediLogic supplies, over the window stated above. It is a field result published as reported, not a controlled trial we ran.
04Sizing
The opening quantity was set against total volume and the ongoing ones against daily flow, five days a week. Both are bases rather than rates; a quantity for your own lagoon comes from the planner.
05Method
Accumulation depth converted to dry weight at the start and the close.
06Outcome
The plant reported the work costing a fraction of the quoted dredge. Deferred, not resolved: the inert fraction is still on the bottom, and it will need a dredge eventually.
At the start
20.5 per cent of the lagoon volume taken up by accumulation, against a $2.5 million dredging quotation.
At the close
672,659 dry pounds digested — about 1,682 wet tons — and the dredge not carried out.
07Limits
The closing accumulation is not published as a percentage or a depth, so the reduction cannot be checked against the opening 20.5 per cent. Nothing was left untreated. The lagoon is not named and no location is given, so the result cannot be traced to a works. Neither the volatile fraction at the start nor the method used to convert depth to dry weight is recorded.
Only the volatile organic fraction of a sludge responds to any of this. Grit, sand, silt, mineral precipitates and plastics remain at any dose, here and everywhere else.
—What we would supply
Spike and Puck are sinking solids for bottom sludge. Maintain is a soluble pouch for organic load in the water column, with Polar for cold-water conditions. The planner calculates quantities only for products with a written dose method; Puck and Polar need a separate review.
Use the written dose method for your product and lagoon. A quantity reported in a case study was chosen for that site and should not be used as your application rate.
—Read next
Wastewater lagoons
Municipal24 weeks
of accumulated solids digested
Just over five feet of accumulated solids in the primary aerated lagoon, assessed at 2,365 dry tons. The plant wanted a route that did not involve dredging.
Wastewater lagoons
MunicipalFive months, May to October
reduction in solids volume overall
Accumulated solids across two lagoon cells, against a specification calling for a 50 per cent reduction. The treatment window was bounded by water temperature, which has to stay above roughly 55°F for the organisms to work at all.
Wastewater lagoons
Industrial12 months
reduction in accumulated solids
Accumulated solids had cut hydraulic retention time to 13 days, capping what the facility could put through the plant and putting effluent quality within sight of a limit.
Your lagoon next
This result came from a different plant. Your sludge composition and operating conditions need their own assessment. Send us your lagoon details for a dosing review; do not use the quantity on this page as your application rate.
