Wastewater lagoons

Resort wastewater lagoon, Hawaii

A forty-year-old lagoon carrying heavy accumulated solids and an effluent suspended-solids figure the resort could not hold.

Single digits

effluent suspended solids, from a starting figure that was never recorded

Field resultNo method statedConfounded

Duty: Wastewater lagoons
Sector: Municipal
Treatment window: 30 days
What was counted: Suspended solids

Dosed at 1 ppm of influent flow
A fine-bubble aeration system was installed during the same window

Aerial view of a multi-cell aerated wastewater lagoon, its surface broken by aeration, with grass berms dividing the cells and a small control building alongside. — Illustration — an operating aerated lagoon, not the works described on this page.

01The plant

What was being treated

A resort wastewater lagoon roughly forty years old.

02Before

How the material got there

The lagoon had lost the ability to settle out suspended solids. The effluent ran dark green, with heavy growth and floating material blanketing the surface.

03Treatment

What was applied, and how

A thirty-day opening programme with a maintenance dose after it. Fine-bubble diffused aeration was installed over the same period.

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

What the quantity was set against

Set against influent flow rather than lagoon volume, which suits a water-column problem — the target was what was arriving, not what had settled.

05Outcome

What followed

The site manager reported the effluent still improving at the close of the thirty days.

At the start

Dark green effluent, suspended solids very high, heavy surface growth and floating material across the lagoon.

At the close

Suspended solids in single figures to low double figures, the surface growth gone and the effluent clear.

06Limits

What this record does not establish.

No opening suspended-solids figure was published, so the reduction has no arithmetic behind it — 'very high' to 'single digits' is a description, not a measurement. Aeration was installed during the same window, so the result cannot be attributed to the product alone. No method, no laboratory and no untreated comparison are 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

For this duty, in our range.

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.

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—Read next

The same duty, measured somewhere else.

Wastewater lagoons
Agricultural lagoon serving 8,000 dairy cows, South America
Agricultural4 months
83%
reduction in total suspended solids
Field result
A lagoon loaded well past what it was built for, carrying a foam layer across most of the surface and blocking the irrigation draw.
- TSS 18,650 mg/L to 3,220 mg/L
- BOD₅ 5,195 mg/L to 2,752 mg/L, a 47 per cent reduction
- COD rose over the same period, from 18,211 mg/L to 19,303 mg/L
- Around 70 per cent of the water surface reported clear of foam
Suspended solidsBOD and COD
Wastewater lagoons
Swine manure lagoon
Agricultural6 weeks
91%
reduction in total suspended solids
Field resultThird-party lab
Suspended solids and phosphorus in a manure lagoon at concentrations that constrained where the contents could go.
- Phosphorus down 85 per cent
- COD down 84 per cent
- Figures attributed to an accredited outside laboratory
Suspended solidsBOD and COD
Wastewater lagoons
Barbourville, Kentucky
Municipal24 weeks
43.3%
of accumulated solids digested
Field result
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.
- 1,025 dry tons removed
- Average depth 5.08 ft to 2.65 ft
Sludge depth and solids

All field results

Your lagoon next

This was measured somewhere else.

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.

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