Sewage Lagoon Closure
Sewage lagoons are authorized and operated under the wastewater regulations in Title 18, Chapter 72 of the Alaska Administrative Code (18 AAC 72). However, sewage lagoon closures in which the sludge is left in place must meet the requirements for closing a sewage solids monofill under the solid waste regulations in 18 AAC 60.470.
Prior to closing the lagoon in place, a sewage lagoon closure plan must be approved by the Solid Waste Program. The closure plan must be submitted at least 60 days before the lagoon is scheduled to be closed.
Closure Plan Requirements
- A general description of the facility, including the site topography, geology, climate, and surface and groundwater hydrology.
- A description of the anticipated post-closure use of the property.
- A description of how public access to the lagoon will be restricted for at least three years.
- A map of the area within 500 feet showing major topographical, geological, hydrological and biological or man-made features, including drinking water wells or intakes.
- A site plan and cross-sectional drawing of the lagoon.
- A description of the final cover, including installation of at least two feet of soil cover, grading for adequate drainage, and revegetation.
- For a lined lagoon, a discussion of how the lagoon will be capped, or the liner removed and disposed, so that water does not continue to accumulate within the closed lagoon.
- A description of how the closure demonstration requirements of 18 AAC 60.490 will be met.
- A copy of the deed or another legal document that identifies the landowner.
- If the operator of the lagoon is not the landowner, a signed written statement or copy of a lease agreement showing that the landowner consents to the permanent presence of the sewage solids monofill on the property and any associated conditions required by the department.
- A post-closure monitoring plan that meets the requirements of 18 AAC 60.490 and 60.800-860. The normal post-closure monitoring period is five years. The plan will include:
- Annual visual monitoring
- Methane monitoring in buildings closer than 500 feet to the lagoon, if the lagoon contains more than 2,500 cubic yards of waste.
- Surface water or groundwater monitoring if this was required during the active life of the lagoon.